KR20140105775A - Composite phase difference plate and composite polarizing plate using same - Google Patents

Abstract

An adhesive layer 31 composed of a cured product of an active energy ray-curable resin composition and a (meth) acrylic resin layer 14 are laminated on a (meth) acrylic resin layer 14 of a first retardation plate 10 having a (meth) And a second retardation film 18 made of a cycloolefin resin film are laminated in this order. The adhesive layer 31 is formed by laminating an N-substituted (meth) acrylamide and a compound having a (meth) acryloyloxy group in the molecule Is formed of a curable resin composition containing a curable component and a composite retardation plate (20) having a thickness of 10 m or less is provided. The composite retardation plate 20 is laminated on one side of the polarizing film 42 and the protective film 44 is laminated on the other side to form a composite polarizing plate 50.

Description

Technical Field [0001] The present invention relates to a composite retardation plate and a composite polarizer using the same,

The present invention relates to a composite retardation plate suitably used for a liquid crystal display device in which a retardation plate comprising a (meth) acrylic resin layer and a retardation film composed of a cycloolefin-based resin film are laminated, and a composite polarizing plate in which the retardation plate is combined with a polarizing plate .

BACKGROUND ART [0002] Liquid crystal display devices are used in various display devices, taking advantage of features such as low power consumption, low voltage operation, light weight, and thinness. The liquid crystal display device is composed of many materials such as a liquid crystal cell, a polarizing plate, a retardation plate, a condensing sheet, a diffusion film, a light guide plate, and a light reflection sheet. Therefore, improvements have been actively made aiming at improvement in productivity, light weight, and brightness by reducing the number of constituent films or reducing the thickness of a film or a sheet.

In many cases, the retarder is produced by stretching a resin film. The main chain of the resin is gathered at the elongation axis by stretching. The resin having no bulky group in the side chain has the maximum refractive index in the stretching axis direction, and the direction becomes the slow axis. Such a resin is called a resin having a positive refractive index anisotropy, and a retardation plate formed of the resin is sometimes referred to as a positive retardation plate. Recently, a stretched film of a cycloolefin resin having a small photoelastic coefficient has been widely used as a positive retardation plate. On the other hand, in a resin having a bulky group in the side chain, the refractive index in the side chain direction, that is, the direction orthogonal to the stretching axis becomes maximum, so that the stretching axis direction becomes the fast axis. Such a resin is called a resin having a negative refractive index anisotropy, and a retardation plate formed of the resin is sometimes called a negative retardation plate. As a resin having negative refractive index anisotropy, styrene type resin having styrene as a main constituent unit and (meth) acrylic type resin having acrylic acid ester or methacrylic acid ester as a main constituent unit have been known heretofore.

The (meth) acrylic resin has a low appearance of retardation. On the other hand, the styrene-based resin exhibits a large retardation manifestation, but has problems such as chemical resistance and mechanical strength. So, there is an attempt to combine both. For example, Japanese Patent No. 4770176 (Patent Document 1) discloses a resin multilayer film in which a second layer of a (meth) acrylic resin composition on both sides of a first layer made of a styrenic resin is laminated by coextrusion, Stretching is performed to give an in-plane retardation to form a retarder. Japanese Patent Laid-Open Publication No. 2009-175222 (Patent Document 2) discloses a laminated polarizing plate in which a retardation plate made of a resin multilayer film disclosed in Patent Document 1 is laminated on a polarizing film through an adhesive layer, And a primer layer interposed between the adhesive layer and the adhesive layer, thereby enhancing the adhesive strength of both.

Further, in the case of a retarder applied to a liquid crystal display, two or more films may be laminated and used from the viewpoint of optical compensation. In this case, in general, from the viewpoint of workability, a pressure-sensitive adhesive made of an acrylic resin is used for bonding these films. For example, Japanese Patent Application Laid-Open No. 2010-217870 (Patent Document 3) discloses a method in which a first retardation plate made of an olefin resin having a cycloolefin resin as a typical example, Layered second retardation plate is laminated and laminated on the polarizing film through the adhesive layer on the first retardation plate side to form a composite polarizing plate.

On the other hand, it is also known to adhere two kinds of adherends to each other with an adhesive which is cured by irradiation with an active energy ray, which is a typical example of ultraviolet rays. For example, Japanese Patent No. 2805225 (Patent Document 4) discloses a process for producing a cycloolefin-based resin, which includes a reactive monomer or a reactive oligomer having an acrylic group and a photopolymerization initiator in order to bond the molded article of the cycloolefin- A method of curing an adhesive by irradiating ultraviolet rays after bonding the two with an ultraviolet curing type adhesive is described. Japanese Unexamined Patent Publication (Kokai) No. 2005-62443 (Patent Document 5) discloses a method in which a transparent substrate, which is a typical example of glass, a retardation film made of an organic polymer material such as a cycloolefin resin, and an adhesive made of an acrylic ultraviolet- , And the adhesive is cured by irradiation with ultraviolet rays to make the thickness of the adhesive layer 10 m or less.

In the case of using a pressure-sensitive adhesive as disclosed in Patent Document 3 for bonding a cycloolefin-based resin film and a (meth) acrylic resin film, the thickness of the pressure-sensitive adhesive layer of at least about 15 μm is required in order to maintain a proper pressure- It is an obstacle in reducing the thickness of the panel or the liquid crystal display device. When the cycloolefin resin film and the (meth) acrylic resin film are bonded with a pressure-sensitive adhesive having a thickness of 10 占 퐉 or less, the adhesive force is not sufficient, and the laminated retardation plate itself, When a composite polarizing plate having a retardation plate attached to a polarizing film or a liquid crystal panel having a compound polarizing plate bonded to a liquid crystal cell glass is exposed to a high temperature, the film can not sufficiently absorb shrinkage and peeling or peeling occurs between the film and the pressure- , Defects such as foaming may occur.

On the other hand, it is also conceivable to use acrylic-based ultraviolet-curing resin as an adhesive for curing the cycloolefin-based resin film and the (meth) acrylic-based resin film and to cure them by ultraviolet irradiation. However, commercially available acrylic- It was difficult to obtain a sufficient adhesive force.

Disclosure of the Invention An object of the present invention is to provide a retardation plate comprising a cycloolefin resin film laminated on the (meth) acrylic resin layer of a retardation plate having a (meth) acrylic resin layer on its outermost surface, ) It is an object of the present invention to improve the adhesion between the acrylic resin layer and the cycloolefin-based resin film while keeping the film thickness to 10 m or less.

Another object of the present invention is to provide a polarizing plate which is obtained by bonding the composite retardation plate thus obtained to one surface of a polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin, The present invention provides a composite polarizing plate comprising:

As a result of the research, it has been found that a combination of two specific (meth) acrylic compounds as the curable component to form an active energy ray curable resin composition and using this as an adhesive can provide a high adhesion strength between the (meth) acrylic resin film and the cycloolefin resin film The present invention has been accomplished on the basis of these findings.

That is, according to the present invention, the (meth) acrylic resin layer of the first retardation plate having the (meth) acrylic resin layer on the outermost surface is provided with an adhesive layer comprising a cured product of the active energy ray- And the second retardation film made of a film are laminated in this order. The above active energy ray-curable resin composition is characterized by containing N-substituted (meth) acrylamide and a compound having a (meth) acryloyloxy group in its molecule as a curing component And the above-mentioned adhesive layer is provided with a composite retardation plate having a thickness of 10 mu m or less.

In this compound phase difference plate, N-substituted (meth) acrylamide, which is one of the curing components constituting the active energy ray-curable resin composition,

(I)

(I)

(Wherein Q ₁ represents a hydrogen atom or a methyl group, Q ₂ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Q ₃ represents an alkyl group having 1 to 6 carbon atoms which may have a hydroxyl group, or Q ₂ and Q ₃ together form a 5-membered ring or a 6-membered ring which may be taken together with the nitrogen atom to which they are bonded and the oxygen atom as a ring member)

Is preferable.

The compound having a (meth) acryloyloxy group in the molecule, which is another curing component constituting the active energy ray-curable resin composition,

(II)

(II)

(Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group having 1 to 6 carbon atoms)

Is preferably an alkyl (meth) acrylate represented by the following general formula

The active energy ray-curable resin composition contains 60 to 80% by weight of N-substituted (meth) acrylamide and 40 to 80% by weight of a compound having a (meth) acryloyloxy group in the molecule based on the total amount of the curable component. By weight to 20% by weight. When a combination of the N-substituted (meth) acrylamide represented by the formula (I) and the alkyl (meth) acrylate represented by the formula (II) is employed, 60 to 80% by weight of the substituted (meth) acrylamide and 40 to 20% by weight of the alkyl (meth) acrylate represented by the formula (II).

In these composite retardation plates, the first retardation plate may be composed of a single film of a (meth) acrylic resin, but it may be composed of a laminated film including a retardation developing layer made of another resin in addition to the (meth) acrylic resin layer You may. In this case also, the second retardation plate made of the cycloolefin-based resin film is bonded to the (meth) acrylic resin layer through the active energy ray-curable resin composition specified above. Therefore, when the first retardation plate is constituted by a laminated film, the (meth) acrylic resin layer is made to be the outermost surface to be adhered to the cycloolefin-based resin film.

When the first retardation plate is constituted by the laminated film as described above, the (meth) acrylic resin layer usually has a glass transition temperature of 120 ° C or lower, and the retardation layer is composed of a resin having a glass transition temperature of 120 ° C or higher . From the viewpoint of realizing such a high glass transition temperature and at the same time being a resin having a negative refractive index anisotropy, it is preferable that the retardation developing layer is made of a styrenic resin. Further, the (meth) acrylic resin layer is advantageous from the viewpoint of film formability in that it contains rubber particles.

It is particularly advantageous that the first retardation plate has a three-layer structure in which a (meth) acrylic resin layer is formed on both sides of the retardation developing layer. In this case, the phase difference-generating layer and the (meth) acrylic resin layer formed on both surfaces thereof may have a thickness of about 10 to 100 mu m.

Further, according to the present invention, a protective film made of a thermoplastic resin is laminated on one side of a polarizing film on which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin through a second adhesive layer, A composite polarizing plate in which any one of the above-mentioned composite retardation plates is laminated on the side of the cycloolefin based resin film through a third adhesive layer is also provided.

This composite polarizing plate can be combined with a liquid crystal cell to form a liquid crystal display panel. In this case, the composite polarizing plate is bonded to the liquid crystal cell on the side of the compound phase difference plate, that is, on the side of the first retardation plate having the (meth) acrylic resin layer. Thus, this liquid crystal display panel comprises a liquid crystal cell and the above-mentioned composite polarizing plate, and the composite polarizing plate is bonded to the liquid crystal cell on the side of the composite retardation plate.

INDUSTRIAL APPLICABILITY According to the present invention, compared to a conventional composite retardation plate in which a first retardation plate including a (meth) acrylic resin layer and a second retardation plate comprising a cycloolefin based resin film are bonded via an adhesive, Therefore, it is possible to reduce the thickness of the composite retarder, and furthermore, the thickness of the liquid crystal panel. Also, the adhesion between the cycloolefin resin film and the (meth) acrylic resin layer is good.

1 is a schematic cross-sectional view showing an example of a preferable layer configuration of a composite retarder according to the present invention.
2 is a schematic cross-sectional view showing an example of a preferable layer configuration of a composite polarizing plate according to the present invention.

[Composite retardation plate]

The composite retardation plate of the present invention is a composite retardation plate comprising a (meth) acrylic resin layer of a first retardation plate having a (meth) acrylic resin layer on its outermost surface, an adhesive layer composed of a cured product of an active energy ray- And a second retardation plate made of an olefin-based resin film. Here, the first retardation plate may be one whose top surface is a (meth) acrylic resin layer adhered to the second retardation plate made of a cycloolefin-based resin film and having a phase difference. Specifically, it may be a single film of a (meth) acrylic resin, or may be a multilayer film including a retardation-releasing layer made of another resin in addition to a (meth) acrylic resin layer. Among them, it is preferable that a (meth) acrylic resin layer is formed on one side or both sides of the retardation developing layer made of a resin different from the (meth) acrylic resin, so that the retardation is expressed.

As used herein, the term "(meth) acrylic resin" is a resin having a (meth) acrylic acid ester as a main constituent unit, as described in the section "BACKGROUND ART". The term "(meth) acrylic acid" means that any of acrylic acid and methacrylic acid may be used, and "(meth) acrylic acid ester" means any of acrylic acid ester and methacrylic acid ester. In the present specification, "(meth)" when "(meth) acrylamide", "(meth) acrylate", "(meth) acryloyl"

An example of a preferable layer configuration of the composite retarder according to the present invention is shown in a schematic sectional view in Fig. The compound phase difference plate of the present invention will be described with reference to Fig. 1, an adhesive layer 31 and a second retardation film 18 made of a cycloolefin resin film are laminated in this order on a first retardation plate 10 including a (meth) acrylic resin layer And laminated to form the composite retarder 20 of the present invention. The adhesive layer 31 is formed of a cured product of the active energy ray-curable resin composition. In the example shown in this figure, the first retardation film 10 is formed in such a state that (meth) acrylic resin layers 14 and 15 are formed on both sides of the retardation film 12 mainly contributing to the development of the retardation function .

As described above, since the (meth) acrylic resin itself has a negative refractive index anisotropy and gives a negative retardation film by stretching, the single film can be used as the first retardation film 10. 1, the phase difference developing layer 12 and the (meth) acrylic resin layer 15 are omitted, and only the (meth) acrylic resin layer 14 is used as the first retardation film 10 . However, as mentioned above, since the (meth) acrylic resin itself has a small retardation manifestation, it is preferably used in combination with the retardation developing layer 12. In this case, a state in which the (meth) acrylic resin layer 14 is formed on one side of the retardation developing layer 12, in other words, the second retardation film 18 made of the cycloolefin resin film in Fig. 1 The first retardation plate 10 may be used in a state in which the (meth) acrylic resin layer 15 located therebetween is omitted. However, when the (meth) acrylic resin layers 14 and 15 are formed on both sides of the retardation developing layer 12 as shown in FIG. 1, the (meth) acrylic resin layers 14 and 15 ) Serves also as a protective layer of the phase difference manifestation layer 12. Hereinafter, the adhesive used for forming the first retardation plate 10, the second retardation plate 18, and the adhesive layer 31 that adheres to each other will be described in order.

[First retardation plate]

1, the first retardation plate 10 constituting the composite retardation plate 20 preferably has a structure in which the retardation layer 12 and one surface thereof (the second retardation layer 12 made of a cycloolefin resin film, (Meth) acrylic resin layer 14 laminated on the retardation layer 12 and the (meth) acrylic resin layer 14 laminated on both sides thereof (more specifically, 14 and 15, respectively. When the (meth) acrylic resin layer is formed on one side or both sides of the retardation developing layer 12 as described above, the retardation developing layer 12 can be made of, for example, a styrene resin. Since the styrene-based resin has a bulky phenyl group in the side chain, the refractive index in the direction perpendicular to the stretching axis (the direction perpendicular to the stretching axis and the thickness direction in the plane) becomes large when uniaxially stretched, and exhibits a negative refractive index anisotropy. In addition, the occurrence of phase difference is also significant. Thus, the film made of the styrene-based resin is suitable as the retardation-generating layer 12 for imparting a negative retardation plate. The negative retardation film is a film in which the refractive index in the direction of the maximum refractive index (slow axis direction) in the plane is n _x , the refractive index in the direction perpendicular to the direction (fast axis direction) is n _y and the refractive index in the thickness direction is n _z , n _z ≒ n _x > n _y , and the N _z coefficient is approximately 0 (zero). Here, the N _z coefficient is defined by the following equation (1).

N _z coefficient = (n _x -n _z ) / (n _x -n _y ) (1)

The styrene-based resin may be a homopolymer of styrene or a derivative thereof, or may be a copolymer of styrene or a derivative thereof and a copolymerizable monomer other than styrene or a derivative thereof. The styrene derivative is a compound in which a substituent is bonded to styrene, and examples thereof include alkyl styrenes such as o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ; Substituted styrenes such as hydroxystyrene, tert-butoxystyrene, vinylbenzoic acid, o-chlorostyrene and p-chlorostyrene, in which a benzene nucleus of styrene has a hydroxyl group, an alkoxy group, a carboxyl group, a halogen and the like. A ternary copolymer obtained by copolymerizing a styrene or styrene derivative with a cyclic olefin monomer and a cyclic olefin monomer may also be used. Among them, the styrene-based resin is preferably a copolymer of styrene or a styrene derivative with at least one monomer selected from acrylonitrile, maleic anhydride, methyl methacrylate and butadiene in view of heat resistance, Similarly, from the viewpoint of heat resistance, it is preferable that the styrene-based resin (phase difference-generating layer 12) has a glass transition temperature of 120 캜 or higher.

It is preferable that the thickness of the phase difference developing layer 12, particularly the phase difference developing layer 12 made of a styrene series resin, is 10 to 100 탆. When the thickness is less than 10 mu m, a sufficient retardation value is hardly expressed by stretching. On the other hand, when the thickness exceeds 100 탆, the impact strength of the retarder tends to be weak, and the phase difference due to external stress tends to increase.

Examples of the (meth) acrylic resin constituting the (meth) acrylic resin layers 14 and 15 include a homopolymer of an alkyl methacrylate or an alkyl acrylate, a copolymer of an alkyl methacrylate and an alkyl acrylate And the like. Specific examples of the methacrylic acid alkyl ester include methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like. Specific examples of the acrylic acid alkyl ester include methyl acrylate, ethyl acrylate and propyl acrylate, . Commercially available (meth) acrylic resins may be used for such (meth) acrylic resins. As the (meth) acrylic resin, a so-called impact (meth) acrylic resin may be used.

It is possible to improve the chemical resistance and mechanical strength of the first retardation film 10 by laminating the (meth) acrylic resin layers 14 and 15 on the retardation developing layer 12. In order to further improve the mechanical strength, it is also preferable to include rubber particles in the (meth) acrylic resin layers 14 and 15. The rubber particles are preferably of acrylic type. Here, the acrylic rubber particles are rubber-elastic particles obtained by polymerizing an acrylic monomer containing an acrylic acid alkyl ester as a main component such as butyl acrylate or 2-ethylhexyl acrylate in the presence of a polyfunctional monomer. The acrylic rubber particles may be a single layer of such rubber-elastic particles, or a multi-layer structure having at least one rubber elastic layer. As the acrylic rubber particles having a multilayered structure, those having rubber elastic particles as mentioned above as the nuclei and covering the periphery thereof with a hard methacrylic acid alkyl ester polymer, those having a hard methacrylic acid alkyl ester polymer as a nucleus , The periphery of which is covered with an acrylic polymer having rubber elasticity as described above or the case where the periphery of a hard core is covered with a rubber elastic acrylic polymer and the periphery thereof is covered with a hard methacrylic acid alkyl ester polymer . The average diameter of the rubber particles formed of the elastic layer is usually in the range of about 50 to 400 nm.

The content of the rubber particles in the (meth) acrylic resin layers 14, 15 is usually about 5 to 50 parts by weight per 100 parts by weight of the (meth) acrylic resin. (Meth) acrylic resin and acrylic rubber particles are commercially available in the form of a mixture thereof. Therefore, commercially available products thereof can be used. Examples of commercially available (meth) acrylic resins containing acrylic rubber particles include "HT55X" and "Technoloy S001" sold by Sumitomo Chemical Co., "Technoloy S001" is sold in film form.

The (meth) acrylic resin composition containing rubber particles as described above generally has a glass transition temperature of 120 ° C or lower. In the present invention, a (meth) acrylic resin composition having a glass transition temperature of 110 ° C or lower is preferably used .

It is preferable that the glass transition temperature of the retardation developing layer 12 is 120 DEG C or higher and the glass transition temperature of the (meth) acrylic resin layer 14 or 15 is 120 DEG C or lower, particularly 110 DEG C or lower desirable. It is also preferable that the glass transition temperatures of the two resins do not overlap and that the retardation developing layer 12 has a glass transition temperature higher than that of the (meth) acrylic resin layers 14 and 15. This is because the production of a retardation plate by co-extrusion described below is made easier.

The thickness of the (meth) acrylic resin layers 14 and 15 is preferably 10 to 100 탆.

The composite retardation plate 20 is obtained by co-extruding, for example, a resin for forming the retardation developing layer 12 and a resin for forming the (meth) acrylic resin layers 14 and 15, In-plane retardation to the retardation film. Further, a single layer film is separately prepared from the resin forming the phase difference manifestation layer 12 and the resin forming the (meth) acrylic resin layer 14, 15, and then laminated films are formed by heat fusion by heat lamination. And then stretching the coated film. The stretching is not particularly limited as long as a desired in-plane retardation value can be obtained. For example, it may be longitudinal uniaxial stretching, tenter horizontal uniaxial stretching, simultaneous biaxial stretching, and sequential biaxial stretching.

As described above, the composite retardation plate 20 preferably has a three-layer structure in which (meth) acrylic resin layers 14 and 15 are laminated on both surfaces of the retardation developing layer 12. In this case, these (meth) acrylic resin layers can have almost the same thickness. By having a three-layer structure, the mechanical strength and chemical resistance of the retarder can be further improved. In the case of a three-layer structure, the total film thickness is 30 to 200 mu m, preferably 30 to 150 mu m, more preferably 30 to 100 mu m.

It is preferable that the first retardation plate 10 has an in-plane retardation Re in the range of 20 to 120 nm and that the Nz coefficient defined by the above formula (1) is in the range of more than -2 and less than -0.5 desirable. The in-plane retardation Re is a value obtained by multiplying the in-plane birefringence of the film by the thickness of the film. Using the in-plane biaxial refractive indexes n _x and n _y defined in relation to the formula (1) Is defined by the following equation (2). The retardation (Rth) in the thickness direction is a value obtained by multiplying the thickness direction birefringence index by the thickness of the film. The refractive indexes n _x and n _{y in the in-} plane biaxial direction, the refractive index n _{z in the} thickness direction, , And is defined by the following equation (3).

Plane retardation value Re = (n _x -n _y ) x d (2)

The retardation value along the thickness direction (Rth) = _{[(n x + n y) /} 2-n z ] × d (3)

The in-plane retardation Re, the thickness direction retardation (Rth), and the Nz coefficient can be obtained by various commercially available phase difference systems. The phase difference or the Nz coefficient may be a value in the vicinity of the center of the visible light, for example, between 500 and 600 nm. In this specification, when the measurement wavelength is not specifically described, the value is set to a value at a wavelength of 590 nm.

[Second retardation plate]

1, the second retardation plate 18 constituting the composite retardation plate 20 of the present invention has a (meth) acrylic resin layer 14 formed on the outermost surface of the first retardation plate 10, Through an adhesive layer 31 made of a cured product of the active energy ray-curable resin composition. Here, the second retarder comprises a cycloolefin-based resin film. The cycloolefin-based resin is a thermoplastic resin having a unit of a monomer comprising a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene-based monomer, and is also referred to as a thermoplastic cycloolefin-based resin. The cycloolefin resin may be a hydrogenated product of a ring-opening polymer of the above cycloolefin or a ring-opening copolymer using two or more cycloolefins, and may be an aromatic compound having a polymerizable double bond such as a cycloolefin, a chain olefin, May be used. A polar group may be introduced into the cycloolefin-based resin.

When a cycloolefin is a copolymer of an aromatic compound having a chain olefin and / or a vinyl group, ethylene or propylene may be used as the chain olefin, and aromatic compounds having a vinyl group such as styrene,? -Methylstyrene, Styrene, and the like can be used, respectively. In such a copolymer, the unit of the monomer comprising cycloolefin may be 50 mol% or less, and in this case, it is preferably about 15 to 50 mol%. Particularly, when the second retardation plate is constituted by using a ternary copolymer comprising a cycloolefin, a chain olefin and an aromatic compound having a vinyl group, the content of the unit of the monomer composed of cycloolefin is set to a relatively small amount as described above . In this case, the content of the unit of the monomer composed of the chain olefin is usually 5 to 80 mol%, and the content of the unit of the monomer composed of the aromatic group having the vinyl group is usually 5 to 80 mol%.

Suitable commercially available products as the cycloolefin-based resin can be used. For example, TOPAS manufactured by TOPAS ADVANCED POLYMERS GmbH in Germany, TOPAS sold by Polyplastics in Japan, ATON sold by JSR, and Zeon sold by Nippon Zeon Co., ZEONOR "and" Zeonex "sold by Mitsui Chemicals, Inc., and" Arpel "(all trade names) sold by Mitsui Chemicals, Inc. Known methods such as a solvent casting method and a melt extrusion method are suitably used for film formation of such cycloolefin-based resin.

The cycloolefin-based resin film is subjected to uniaxial stretching or biaxial stretching to give a retardation to form a retarder. The draw ratio at this time is usually 1.1 to 5 times, preferably 1.1 to 3 times. The retardation plate obtained by stretching is preferably thin, but if it is too thin, the strength tends to deteriorate and the workability tends to be poor. On the other hand, if it is too thick, transparency deteriorates or the weight of the compound retardation plate or complex polarizer increases . From this viewpoint, the thickness of the second retardation plate made of the cycloolefin-based resin is preferably 5 to 150 占 퐉, more preferably 10 to 100 占 퐉, particularly preferably 15 to 80 占 퐉.

There is also a cycloolefin-based resin film that is preliminarily formed and, in some cases, commercially available in a state where a further retardation is imparted. Among them, if the film is a film before imparting a retardation, as long as it has a retardation as the original film of the second retardation film in the present invention, the film may be used as the second retardation film itself in the present invention have. Examples of commercially available products of such cycloolefin-based resin films include "Zeonoah Film" sold by Nippon Zeon Co., Ltd., "Aton Film" sold by JSR Corporation, Sekisui Igaku Kogyo Co., And "SCA40" (all trade names).

The cycloolefin-based resin film may contain additives such as a residual solvent, a stabilizer, a plasticizer, an anti-aging agent, an antistatic agent and an ultraviolet absorber if necessary, as long as the object of the present invention is not impaired. Further, a leveling agent may be contained in order to reduce surface roughness.

In the present invention, the second retardation plate 18 made of a cycloolefin-based resin film has an in-plane retardation Re in the range of 30 to 150 nm and an Nz coefficient defined by the foregoing formula (1) 1 > and less than 2.

The second retardation plate made of the cycloolefin based resin film is adhered to the first retardation plate including the (meth) acrylic resin layer using the adhesive described below. In order to improve the adhesiveness, the adhesive surface of the retardation plate containing the (meth) acrylic resin layer and / or the cycloolefin resin film bonded thereto is subjected to plasma treatment, corona treatment, ultraviolet ray irradiation treatment, A surface treatment such as a frame (flame) treatment, a saponification treatment, a primer treatment or the like may be appropriately carried out. Hereinafter, the adhesive used for adhesion between the retarder including the (meth) acrylic resin layer and the cycloolefin resin film will be described.

[Adhesive for sticking the first retardation plate and the second retardation plate]

In the present invention, the adhesion between the (meth) acrylic resin layer 14, which is the outermost surface of the first retardation film 10, and the second retardation film 18 made of a cycloolefin resin film, A resin composition is used. The active energy ray curable resin composition contains a compound capable of curing upon irradiation with an active energy ray, that is, a curable component. In the present invention, a composition comprising N-substituted (meth) acrylamide and a compound having a (meth) acryloyloxy group in its molecule as a curing component is employed.

≪ N-substituted (meth) acrylamide &

N-substituted (meth) acrylamide is a (meth) acrylamide having a substituent at the N-position. A typical example of the substituent is an alkyl group which may be further substituted, and may form a ring together with the nitrogen atom of (meth) acrylamide. In addition to the carbon atom and the nitrogen atom of (meth) acrylamide, An oxygen atom may be contained as a ring member. A substituent such as alkyl or oxo (= O) may be bonded to the carbon atom constituting the ring. N-substituted (meth) acrylamides can generally be prepared by the reaction of (meth) acrylic acid or its chloride with a primary or secondary amine.

The N-substituted (meth) acrylamide is particularly preferably represented by the above formula (I). In the above formula (I) representing a suitable N-substituted (meth) acrylamide, when Q ₂ is an alkyl group and Q ₃ is an alkyl group which may have a hydroxyl group, . When Q ₃ is an alkyl group having a hydroxyl group, this corresponds to a hydroxyalkyl group. Q ₂ and Q ₃ are taken together to form a 5-membered ring or a 6-membered ring when they form a 5-membered or 6-membered ring which may have an oxygen atom as a ring member, together with the nitrogen atom to which they are bonded, (C ₄ H ₈ N-), 2-oxazolidinone-3-yl (C ₂ H ₄ OC (= O) (C ₅ H ₁₀ N-), morpholino (C ₂ H ₄ OC ₂ H ₄ N-), and the like.

Specific examples of the N-substituted (meth) acrylamides corresponding to the formula (I), Q ₂ being a hydrogen atom and Q ₃ being an alkyl group include N-methyl (meth) acrylamide, N- , N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide and N-hexyl (meth) acrylamide. Similarly, specific examples of N-substituted (meth) acrylamides wherein Q ₂ and Q ₃ together are an alkyl group include N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide and the like. Examples of N-substituted (meth) acrylamides wherein Q ₂ is a hydrogen atom and Q ₃ is an alkyl group having a hydroxyl group include N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) Methacrylamide, N- (2-hydroxypropyl) (meth) acrylamide, and the like. Specific examples of N-substituted (meth) acrylamides in which Q ₂ and Q ₃ in formula (I) are united to form a 5-membered ring or a 6-membered ring together with the nitrogen atom to which they are bonded are N- Acryloylpyrrolidine, 3-acryloyl-2-oxazolidinone, 4-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine and the like. Among them, N-hydroxyalkyl (meth) acrylamides such as N-hydroxymethylacrylamide and N- (2-hydroxyethyl) acrylamide are particularly preferable.

Other examples include N-alkyl (meth) acrylamides having long chain alkyl such as N-dodecyl (meth) acrylamide, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) N- (alkoxyalkyl) (meth) acrylamides such as N- (propoxymethyl) acrylamide and N- (butoxymethyl) acrylamide can also be used as N-substituted Meth) acrylamide.

≪ Compound having (meth) acryloyloxy group >

The compound having a (meth) acryloyloxy group in the molecule which is another curable component of the active energy ray-curable resin composition may be various ones having at least one (meth) acryloyloxy group in the molecule, May also be referred to as " (meth) acrylate ". Specifically, a (meth) acryloyloxy group having at least one (meth) acryloyloxy group in the molecule or a compound obtained by reacting two or more kinds of compounds having a functional group and having at least (Meth) acrylate oligomer having two (meth) acrylate oligomers.

(Meth) acrylate monomers include monofunctional (meth) acrylate monomers having one (meth) acryloyloxy group in the molecule, difunctional (meth) acrylate monomers having two (meth) acryloyloxy groups in the molecule (Meth) acryloyloxy groups in the molecule and a trifunctional or higher polyfunctional (meth) acrylate monomer having three or more (meth) acryloyloxy groups.

Among these, monofunctional (meth) acrylate monomers are preferable, and alkyl (meth) acrylates represented by the above formula (II) are particularly preferable. In the formula (II) representing an alkyl (meth) acrylate, when R ₂ is an alkyl group, the alkyl group may be straight-chain or branched if it has 3 or more carbon atoms. Specific examples of the alkyl (meth) acrylate represented by the formula (II) include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) Butyl (meth) acrylate, and tert-butyl (meth) acrylate. Of these, methyl acrylate is particularly preferable.

(Meth) acrylates such as benzyl (meth) acrylate, isobornyl (meth) acrylate such as benzyl (meth) acrylate, (Meth) acrylates of terpene alcohols such as N, N-dimethylaminoethyl (meth) acrylate, and aminoalkyl (meth) acrylates such as 2-phenoxyethyl (meth) acrylate, ethylcarbitol (Meth) acrylate having an ether bond at an alcohol moiety such as phenoxypolyethylene glycol (meth) acrylate and phenoxypolyethylene glycol (meth) acrylate can also be used as monofunctional (meth) acrylates.

Further, monofunctional (meth) acrylate having a hydroxyl group at the alcohol moiety or monofunctional (meth) acrylate having a carboxyl group at the alcohol moiety may be used. Specific examples of the monofunctional (meth) acrylate having a hydroxyl group at the alcohol moiety include 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (Meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, trimethylolpropane mono (meth) acrylate and pentaerythritol mono (meth) acrylate. Specific examples of the monofunctional (meth) acrylate having a carboxyl group at the alcohol moiety include 2-carboxyethyl (meth) acrylate, 1- [2- (meth) acryloyloxyethyl] phthalic acid, 1- [ (Meth) acryloyloxyethyl] hexahydrophthalic acid, 1- [2- (meth) acryloyloxyethyl] succinic acid and 4- [2- (meth) acryloyloxyethyl] trimellitic acid. .

Is an example of a compound having one (meth) acryloyloxy group in the molecule, but a polyfunctional compound having a plurality of (meth) acryloyloxy groups in the molecule may also be a (meth) acrylate used as a curing component have. As described above, the polyfunctional (meth) acrylate includes a bifunctional (meth) acrylate monomer having two (meth) acryloyloxy groups in the molecule, a polyfunctional (meth) acrylate monomer having three or more (Meth) acrylate oligomer having at least two (meth) acryloyloxy groups in the molecule, obtained by reacting two or more kinds of compounds having a trifunctional or higher functional (meth) acrylate monomer and a functional group. These monomers and oligomers will be specifically described below.

Typical examples of the bifunctional (meth) acrylate monomers include alkylene glycol di (meth) acrylates, polyoxyalkylene glycol di (meth) acrylates, di (meth) acrylates of halogen-substituted alkylene glycols, Di (meth) acrylates of aliphatic polyols, di (meth) acrylates of hydrogenated dicyclopentadiene or tricyclodecanedialcohol, di (meth) acrylates of dioxane glycol or dioxanedialcohol, bis Di (meth) acrylates of alkylene oxide adducts of bisphenol F, and epoxy di (meth) acrylates of bisphenol A or bisphenol F, and the like.

More specific examples of the bifunctional (meth) acrylate monomers include ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) (Meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylol propane di (meth) acrylate, pentaerythritol di (meth) acrylate, Acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (Meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, hydroxypivalic acid neopentyl glycol ester Di (meth) acrylate, 2,2-bis [4- {2- (2- (meth) acryloyloxyethoxy) ethoxy} (Meth) acryloyloxyethoxy) ethoxy} cyclohexyl] propane, hydrogenated dicyclopentadienyl (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 1,3-dioxane Acrylate], an acetal compound of hydroxypivalaldehyde and trimethylolpropane [chemical name: 2- (2-hydroxy-1-hydroxyethyl) (1-dimethylethyl) -5-ethyl-5-hydroxymethyl-1,3-dioxane], 1,3,5-tris (2-hydroxyethyl) isocyanurate Di (meth) acrylate, and the like.

Representative polyfunctional (meth) acrylate monomers having a trifunctional or higher functionality are poly (meth) acrylates of tri- or higher aliphatic polyols. Specific examples thereof include glycerin tri (meth) acrylate, trimethylol propane tri (meth) acrylate, ditrimethylol propane tri (meth) acrylate, ditrimethylol propane tetra (meth) acrylate, pentaerythritol tri (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa have.

Other examples include tri (meth) acrylates of tri- or more halogen-substituted polyols, tri (meth) acrylates of alkylene oxide adducts of glycerin, tri (meth) acrylates of alkylene oxide adducts of trimethylolpropane, , 1-tris [2- {2- (meth) acryloyloxyethoxy} ethoxy] propane, 1,3,5-tris [2- (meth) acryloyloxyethyl] isocyanurate, Polyfunctional (meth) acrylate monomers.

On the other hand, (meth) acrylate oligomers include urethane (meth) acrylate oligomers, polyester (meth) acrylate oligomers and epoxy (meth) acrylate oligomers.

The urethane (meth) acrylate oligomer refers to a compound having at least two (meth) acryloyloxy groups in the molecule and having a urethane bond (-NHCOO-). Specifically, a urethanation reaction product of a hydroxyl group-containing (meth) acrylate monomer having a hydroxyl group and at least one (meth) acryloyloxy group in a molecule with a polyisocyanate, or a polyol is reacted with a polyisocyanate (Meth) acrylate monomer having a hydroxyl group and at least one (meth) acryloyloxy group each having a hydroxyl group in the molecule, and the like can be used as the urethanization reaction product of the resulting isocyanato group-containing urethane compound.

Specific examples of the hydroxyl group-containing (meth) acrylate monomer used in the urethanization reaction include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2- Acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, (Meth) acrylate, and the like.

Specific examples of the polyisocyanate used in the urethanization reaction with such a hydroxyl group-containing (meth) acrylate monomer include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, A compound obtained by hydrogenating xylylene diisocyanate and aromatic diisocyanate such as hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, triphenylmethane triisocyanate, dibenzyl benzene triisocyanate, and diisocyanates thereof in a large amount And polyisocyanates obtained by polymerization.

As the polyol for producing the terminal isocyanato group-containing urethane compound by the reaction with the polyisocyanate, a polyester polyol, a polyether polyol and the like can be used in addition to the aliphatic or alicyclic polyol. Specific examples of the aliphatic or alicyclic polyol include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, , Ditrimethylol propane, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylol propionic acid, dimethylol butyric acid, glycerin, hydrogenated bisphenol A and the like.

The polyester polyol is a compound obtained by dehydration condensation reaction of a polybasic carboxylic acid or an anhydride thereof with the above polyols. Specific examples of the polybasic carboxylic acid and its anhydride may be anhydrides which may be anhydrides, for example, succinic acid, adipic acid, (maleic anhydride) maleic acid, (anhydrous) itaconic acid , (Anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, and hexahydrophthalic anhydride.

The polyether polyol may be a polyoxyalkylene-modified polyol obtained by reacting an alkylene oxide with the above polyol or bisphenol in addition to the polyalkylene glycol.

The polyester (meth) acrylate oligomer means a compound having at least two (meth) acryloyloxy groups in the molecule and having an ester bond. Specifically, it can be obtained by a dehydration condensation reaction of (meth) acrylic acid, a polybasic carboxylic acid or an anhydride thereof, and a polyol. Specific examples of the polybasic carboxylic acid or its anhydride used in the dehydration condensation reaction may be an anhydride which is labeled with "(anhydrous)", and examples thereof include succinic acid, adipic acid, (anhydrous) maleic acid , (Anhydrous) phthalic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, and the like. Specific examples of the polyol used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethyl Dipentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutyric acid, glycerin, hydrogenated bisphenol A, and the like.

The epoxy (meth) acrylate oligomer is obtained by the addition reaction of polyglycidyl ether and (meth) acrylic acid, and also has at least two (meth) acryloyloxy groups in the molecule. Specific examples of the polyglycidyl ether used in this addition reaction include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether Sebac ether, bisphenol A diglycidyl ether, and the like.

<Quantitative Ratio of N-Substituted (Meth) Acrylamide and (Meth) Acrylate>

In the present invention, the above-described N-substituted (meth) acrylamide and (meth) acrylate are used in combination as a curing component in the active energy ray-curable resin composition, and their quantitative relationship includes both (Meth) acrylamide is contained in an amount of 60 to 80% by weight, more preferably 70 to 80% by weight, based on the total amount of the curable component, including the compound which cures upon irradiation with an active energy ray, , And 20 to 40% by weight, and more preferably 20 to 30% by weight, of the (meth) acrylate. Similarly, in the case of using the N-substituted (meth) acrylamide represented by the above formula (I) and the alkyl (meth) acrylate represented by the above formula (II), on the basis of the total amount of the curing component, (Meth) acrylamide is 60 to 80 parts by weight, more preferably 70 to 80 parts by weight, and the proportion of the alkyl (meth) acrylate represented by the formula (II) is 20 to 40 parts by weight, By weight, more preferably 20 to 30% by weight. The proportion of the N-substituted (meth) acrylamide represented by the compound represented by the formula (I) is less than 60% by weight in the total of the curing components, in other words, the compound represented by the formula (II) (Meth) acrylate exceeds 40% by weight in the entire curable component, the adhesive strength to the cycloolefin-based resin film tends to be lowered. On the other hand, when the proportion of the N-substituted (meth) acrylamide represented by the formula (I) is more than 80% by weight in the entire curable component, in other words, the compound represented by the formula When the proportion of the (meth) acrylate is below 20% by weight in the entire curable component, the adhesive force to the retarder including the (meth) acrylic resin layer tends to decrease.

&Lt; Photo radical polymerization initiator &gt;

The active energy ray-curable resin composition contains the above-described N-substituted (meth) acrylamide and (meth) acrylate as a curable component, and since they are all radical polymerizable compounds, the composition contains a photo radical polymerization initiator . The photo radical polymerization initiator may be any one capable of initiating polymerization of the radical polymerizable compound by irradiation with an active energy ray, and conventionally known ones can be used. Specific examples of the photoradical polymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxypropyl- Acetophenone based initiators such as -1- [4- (methylthio) phenyl-2-morpholinopropane-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one; Benzophenone based initiators such as benzophenone, 4-chlorobenzophenone and 4,4'-diaminobenzophenone; Benzoin ether initiators such as benzoin propyl ether and benzoin ethyl ether; Thioxanthone initiators such as 4-isopropylthioxanthone; In addition, there are xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, and the like.

The blending amount of the photo radical polymerization initiator is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, per 100 parts by weight of the radically polymerizable compound containing N-substituted (meth) acrylamide and (meth) acrylate Wealth. If the amount of the photo radical polymerization initiator is small, the curing becomes insufficient, and mechanical strength and adhesiveness tend to be lowered. On the other hand, if the amount of the photo radical polymerization initiator is excessively large, the amount of the active energy ray-curable compound in the curable resin composition becomes relatively small, and the durability of the resultant composite retarder may deteriorate.

&Lt; Other optional components that can be incorporated into the curable resin composition &gt;

The active energy ray curable resin composition may further contain a photosensitizer, if necessary. By adding the photosensitizer, the reactivity of the radical polymerization is improved, and the mechanical strength and adhesion of the adhesive layer can be improved. The photosensitizer may be any compound having a maximum absorption at a wavelength longer than 380 nm. Examples of the photosensitizer include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, anthracene compounds, And a photoreducible dye. Examples of carbonyl compounds that can be photosensitizers include benzoin derivatives such as benzoin methyl ether, benzoin isopropyl ether and 2,2-dimethoxy-2-phenylacetophenone; Benzophenone compounds such as benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone and 4,4'-bis (diethylamino) benzophenone; Thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone; Anthraquinone derivatives such as 2-chloro anthraquinone and 2-methyl anthraquinone; Acridone derivatives such as N-methyl acridone and N-butyl acridone, and the like. The anthracene compound preferably has an alkoxy group at the 9th position and the 10th position of the anthracene, and examples of the anthracene compound which can be a photosensitizer include 9,10-dipropoxyanthracene, 2-methyl-9,10- Dihydroxy anthracene, 9,10-dibutoxyanthracene, 2-methyl-9,10-dibutoxyanthracene, 2-ethyl-9,10-dibutoxyanthracene, etc., have. These photosensitizers may be used alone or in combination of two or more. When the photosensitizer is blended, the amount thereof is usually about 0.1 to 20 parts by weight, based on 100 parts by weight of the entire active energy ray curable compound.

The active energy ray-curable resin composition may contain an antistatic agent for imparting antistatic properties. As the antistatic agent, various known ones can be used. For example, cationic surfactants, anionic surfactants, nonionic surfactants, ionic compounds having organic cations other than the cationic surfactants, ionic compounds having organic anions other than the anionic surfactants, conductive inorganic particles, conductive polymers, etc. Can be used. The mixing ratio of these antistatic agents can be suitably determined in accordance with desired characteristics, and is generally about 0.1 to 10 parts by weight, based on 100 parts by weight of the total of the active energy ray curable compound.

The active energy ray-curable resin composition may contain a known polymer additive commonly used in polymers. Examples thereof include primary antioxidants such as phenol and amine type, secondary sulfur antioxidants, hindered amine light stabilizers (HALS), benzophenone, benzotriazole, and benzoate.

A leveling agent may be added to the active energy ray-curable resin composition. When the curable resin composition is applied to the first retardation plate having the (meth) acrylic resin layer on the outermost surface or the second retardation plate composed of the cycloolefin-based resin film, when the releasability is insufficient, Can be improved. As the leveling agent, various compounds having a leveling effect such as a silicone type, a fluorine type, a polyether type, an acrylic copolymer type, a titanate type and the like can be used. The blending ratio of the leveling agent is about 0.01 to 1 part by weight based on 100 parts by weight of the active energy ray curable compound contained in the curable resin composition.

In addition, the active energy ray-curable resin composition may contain a solvent as required. The solvent is appropriately selected in consideration of the solubility of the components constituting the curable resin composition. Commonly used solvents include aliphatic hydrocarbons such as n-hexane and cyclohexane; Aromatic hydrocarbons such as toluene and xylene; Alcohols such as methanol, ethanol, propanol, isopropanol and butanol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Esters such as methyl acetate, ethyl acetate and butyl acetate; Cellosolve such as methylcellosolve, ethylcellosolve and butylcellosolve; And halogenated hydrocarbons such as methylene chloride and chloroform. The compounding ratio of the solvent is suitably determined in view of adjustment of the viscosity depending on processing purposes such as film forming property and an optimum viscosity range in the coating system employed.

The active energy ray curable resin composition for forming the adhesive layer 31 is coated on either the adhesive surface of the first retardation plate 10 or the second retardation plate 18 and another retardation plate is laminated thereon do. For coating the active energy ray-curable resin composition, various coating methods such as doctor blade, wire bar, die coater, comma coater, and gravure coater can be used.

The light source used for the irradiation of the active energy ray is not particularly limited and may be a light source having a light emission distribution with a wavelength of 400 nm or less such as a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, Lamps and the like can be used. Although the light irradiation intensity to the active energy ray-curable resin composition varies depending on the composition, it is preferable that the irradiation intensity in the wavelength range effective for activation of the polymerization initiator is 10 to 2,500 mW / cm 2. If the light irradiation intensity to the active energy ray-curable resin composition is too small, the time required for the reaction to proceed sufficiently is prolonged. On the contrary, if it is excessively large, heat and active energy radiated from the lamp , There is a possibility of causing yellowing of the active energy ray-curable resin composition or deterioration of the adhesive film. The light irradiation time for the active energy ray-curable resin composition is also controlled for each composition and is not particularly limited, but it is preferable to set the accumulated light quantity as a product of irradiation intensity and irradiation time to be 10 to 2,500 mJ / cm 2 Do. If the amount of accumulated light in the active energy ray-curable resin composition is too small, the generation of active species derived from the polymerization initiator is not sufficient, and the curing of the resulting adhesive layer may be insufficient. If the accumulated light amount is too large, the irradiation time becomes very long, which is disadvantageous to the productivity improvement.

[Composite Polarizer]

The composite retardation film 20 of the present invention, which shows an example of the layer structure in Fig. 1, can be combined with a polarizing plate to form a composite polarizing plate. An example of a preferable layer configuration of the composite polarizing plate according to the present invention is shown in a schematic sectional view in Fig. As shown in this figure, a protective film 44 made of a thermoplastic resin is laminated on one side of the polarizing film 42 through the second adhesive layer 32, and the other side of the polarizing film 42 The composite retardation plate 20 described above with reference to Fig. 1 is laminated on the side of the second retardation plate 18 made of the cycloolefin based resin film via the third adhesive layer 33, (50). A pressure sensitive adhesive layer 46 for bonding to another member such as a liquid crystal cell is formed on the surface of the compound retarder 20 opposite to the surface bonded to the polarizing film 42, A separator 48 for adhering and protecting the surface of the pressure-sensitive adhesive layer 46 is provided. On the other hand, in Fig. 2, in order to make the relationship of each layer easy to understand, some of the layers are shown apart from each other, but actually, adjacent layers are brought into contact with each other and brought into close contact with each other. Hereinafter, each member constituting the composite polarizing plate 50 will be described in detail. However, since the compound retarder 20 and the members constituting it are the same as those described above with reference to Fig. 1, their description is omitted.

[Polarizing Film]

Specifically, the polarizing film 42 is adsorbed and aligned on the polyvinyl alcohol-based resin film. The dichroic dye in the polyvinyl alcohol-based resin film can be oriented in the stretching direction by performing uniaxial stretching before, during, or after the adsorption of the dichroic dye. The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate resin include polyvinyl acetate which is a homopolymer of vinyl acetate, as well as copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymer. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins such as ethylene, vinyl ethers, acrylamides having an ammonium group, and the like.

The saponification degree of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, for example, polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like. The polymerization degree of the polyvinyl alcohol-based resin is usually in the range of 1,000 to 10,000, preferably 1,500 to 5,000.

Such a polyvinyl alcohol-based resin film is used as the original film of the polarizing film. The method of forming the polyvinyl alcohol-based resin is not particularly limited, and can be formed by a conventionally known appropriate method. The thickness of the original film made of a polyvinyl alcohol-based resin is not particularly limited, but is, for example, about 10 to 150 占 퐉.

The polarizing film is usually formed by a process of dyeing a polyvinyl alcohol resin film with a dichroic dye and adsorbing the dichroic dye (dyeing process), a process of treating a polyvinyl alcohol resin film adsorbed with a dichroic dye with an aqueous solution of boric acid (Boric acid treatment step), and a step of washing with water after the treatment with the aqueous solution of boric acid (water washing step).

The uniaxial stretching may also be carried out, but the uniaxial stretching of the polyvinyl alcohol based resin film may be carried out before the dyeing treatment step, during the dyeing treatment step, or after the dyeing treatment step. In the case of performing the uniaxial stretching after the dyeing treatment step, the uniaxial stretching may be performed before the boric acid treatment step or during the boric acid treatment step. Of course, it is also possible to perform uniaxial stretching in a plurality of such steps. The uniaxial stretching may be carried out by passing the film between spaced rolls having different circumferential speeds or by sandwiching the film with a thermal roll. Further, dry drawing may be used in which drawing is performed in the air, or may be wet drawing in which drawing is performed in a state of being swollen with a solvent. The stretching magnification is usually about 3 to 8 times.

The dyeing treatment step is carried out, for example, by immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye. As the dichroic dye, iodine or a dichroic organic dye is specifically used. The dichroic organic dyes include C.I. DIRECT RED 39 and the like, and dichromatic direct dyes composed of compounds such as trisazo or tetrakisazo. On the other hand, it is preferable that the polyvinyl alcohol-based resin film is subjected to immersion treatment in water before the dyeing treatment.

When iodine is used as the dichroic dye, a method in which a polyvinyl alcohol resin film is dipped in an aqueous solution containing iodine and potassium iodide is generally employed. The content of iodine in this aqueous solution is usually 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually 0.5 to 20 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye, the temperature of the aqueous solution used for dyeing is usually 20 to 40 占 폚, and the immersion time (dyeing time) in this aqueous solution is usually 20 to 1,800 seconds.

On the other hand, when a dichroic organic dye is used as the dichroic dye, a method in which a polyvinyl alcohol resin film is dipped in an aqueous solution containing a water-soluble dichroic organic dye is generally employed. The content of the dichroic organic dye in this aqueous solution is usually 1 x ^10-4 to 10 parts by weight, preferably 1 x ^10-3 to 1 part by weight, more preferably 1 x ^10-3 To 1 x 10 ^-2 parts by weight. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. When a dichroic organic dye is used as the dichroic dye, the dye aqueous solution used for dyeing usually has a temperature of 20 to 80 캜, and the immersion time (dyeing time) in the aqueous solution is usually 10 to 1,800 seconds.

The boric acid treatment step is carried out by immersing a polyvinyl alcohol-based resin film dyed with a dichroic dye into an aqueous solution of boric acid. The boric acid content in the boric acid aqueous solution is usually 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. In the case where iodine is used as the dichroic dye in the dyeing treatment step described above, the aqueous boric acid solution used in this step preferably contains potassium iodide. In this case, the content of potassium iodide in the aqueous boric acid solution is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. The immersing time in the aqueous boric acid solution is usually 60 to 1,200 seconds, preferably 150 to 600 seconds, more preferably 200 to 400 seconds. The temperature of the boric acid aqueous solution is usually 50 占 폚 or higher, preferably 50 to 85 占 폚, and more preferably 60 to 80 占 폚.

In the subsequent water washing treatment step, the polyvinyl alcohol based resin film after the boric acid treatment is subjected to water washing treatment, for example, by immersing it in water. The temperature of the water in the water washing treatment is usually 5 to 40 占 폚, and the immersion time is usually 1 to 120 seconds. After the washing treatment, the drying treatment is usually carried out to obtain a polarizing film. The drying treatment can be performed using, for example, a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually 30 to 100 占 폚, preferably 50 to 80 占 폚. The drying treatment time is usually from 60 to 600 seconds, preferably from 120 to 600 seconds.

As described above, a polarizing film in which a dichroic dye is adsorbed and aligned on a uniaxially stretched polyvinyl alcohol-based resin film can be produced. The thickness of the polarizing film may be about 5 to 40 mu m.

[Protective film made of thermoplastic resin]

The second retardation plate 18 made of a cycloolefin resin film constituting the composite retardation plate 20 is bonded to one surface of the polarizing film 42 as described above, A separate protective film 44 made of a thermoplastic resin can be bonded to the surface. The protective film 44 is also bonded to the polarizing film 42 through an adhesive. The protective film 44 is widely used as a material for forming a protective film in the related art, for example, a cellulose acetate resin, a polyolefin resin, an acrylic resin, a polyimide resin, a polycarbonate resin, And the like. Among these, from the viewpoints of mass productivity and adhesiveness, it is preferable to use a cellulose acetate resin film as the protective film 44. A cellulose acetate resin film is preferably used as the protective film 44 from the standpoint of ease of installation of the surface treatment layer and optical properties.

The cellulose acetate based resin film is a film made of a cellulose part or a completely acetic acid esterified product, and examples thereof include a triacetyl cellulose film and a diacetyl cellulose film. Fuji Tach TD80UF ", "Fuji Tach TD80UZ ", and Konica Minolta Opt Co., Ltd., which are commercially available products such as those sold by Fuji Film Co., Quot; KC8UY2 ", "KC8UY ", and" KC4UEW "

The polarizing film 42 and the protective film 44 made of a thermoplastic resin are bonded together using a suitable adhesive described later. In order to improve the adhesiveness of both, a surface for improving adhesiveness, such as a plasma treatment, a corona treatment, an ultraviolet ray irradiation treatment, a flame treatment, a saponification treatment, a primer treatment or the like, The treatment may be appropriately carried out. When the protective film 44 is composed of a cellulose acetate resin film and is adhered to the polarizing film 42 using an aqueous adhesive agent described later, as one of preferable surface treatments to be performed on the cellulose acetate resin film, For example. The saponification treatment is carried out by immersing the film in an aqueous solution of an alkali such as sodium hydroxide or potassium hydroxide.

If the protective film 44 made of a thermoplastic resin is thin, the strength is lowered and the workability tends to deteriorate. If the thickness is excessively large, the transparency may be deteriorated or the weight of the composite polarizer 50 Tends to increase. From this viewpoint, the thickness of the protective film 44 is usually 10 to 200 占 퐉, preferably 20 to 150 占 퐉, and more preferably 30 to 100 占 퐉.

The protective film 44 made of a thermoplastic resin may be subjected to surface treatment such as antiglare treatment, hard coat treatment, antistatic treatment and antireflection treatment on the surface opposite to the surface to which the polarizing film 42 is adhered.

[Polarizing Film, Protective Film, and Adhesive for Sticking the Compound Phase Difference Plate]

An adhesive is used for adhesion between the polarizing film 42 and the protective film 44 made of a thermoplastic resin and for adhesion between the polarizing film 42 and the second retardation plate 18 constituting the composite retardation plate 20. [ 2, a second adhesive layer 32 is provided between the polarizing film 42 and the protective film 44, and a third adhesive layer 32 is provided between the polarizing film and the second retardation plate 18, (33) are formed. For this reason, any adhesive may be used as long as it exhibits an adhesive force to both. Examples thereof include an aqueous adhesive in which an adhesive component is dissolved or dispersed in water, and a curable adhesive containing an active energy ray-curable compound. Considering that the surface of the polarizing film 42 is hydrophilic, an aqueous adhesive in which the adhesive component is dissolved or dispersed in water is preferable. The aqueous adhesive is also preferable from the viewpoint that the adhesive layer after curing can be made thin. As the main component of the water-based adhesive, polyvinyl alcohol resin, urethane resin, or the like can be used. On the other hand, the adhesives constituting the second adhesive layer 32 and the third adhesive layer 33 may be the same or different, but it is advantageous from the viewpoint of working efficiency to use the same adhesive as long as proper adhesiveness can be obtained.

When a polyvinyl alcohol-based resin is used as the main component of the water-based adhesive, the polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. The polyvinyl acetate resin may be a copolymer of vinyl acetate and other monomers copolymerizable therewith, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, and acrylamides having an ammonium group. The polyvinyl alcohol-based resin used for the adhesive preferably has an appropriate degree of polymerization. For example, when the aqueous solution has a concentration of 4% by weight, the viscosity of the polyvinyl alcohol resin is preferably in the range of 4 to 50 mPa · sec, more preferably in the range of 6 to 30 mPa · sec Is more preferable.

The degree of saponification of the polyvinyl alcohol-based resin used in the adhesive is preferably 80 mol% or more, more preferably 90 mol% or more. When the degree of saponification of the polyvinyl alcohol-based resin used for the adhesive agent is low, the water resistance of the resulting adhesive layer tends to become insufficient.

The modified polyvinyl alcohol-based resin is preferably used as the adhesive. Examples of the suitable modified polyvinyl alcohol-based resin include an acetacetyl-modified polyvinyl alcohol-based resin, an anion-modified polyvinyl alcohol-based resin, and a cation-modified polyvinyl alcohol-based resin. Use of such a modified polyvinyl alcohol-based resin tends to provide an effect of improving the water resistance of the adhesive layer.

The acetacetyl group-modified polyvinyl alcohol-based resin has an acetacetyl group (CH ₃ COCH ₂ CO-) in addition to the hydroxyl group constituting the polyvinyl alcohol skeleton and may have another acyl group such as an acetyl group . This acetacetyl group is typically present in a state in which the hydrogen atom of the hydroxyl group constituting the polyvinyl alcohol is substituted. The acetacetyl group-modified polyvinyl alcohol resin can be produced, for example, by reacting polyvinyl alcohol with a diketone. Since the acetacetyl group-modified polyvinyl alcohol-based resin has an acetacetyl group which is a highly reactive functional group, it is preferable in improving the durability of the adhesive layer.

The content of the acetacetyl group in the acetacetyl group-modified polyvinyl alcohol-based resin is not particularly limited so long as it is 0.1 mol% or more. The content of the acetacetyl group referred to herein is a value obtained by expressing the molar fraction of the acetacetyl group as the percentage of the total amount of the hydroxyl group, the acetacetyl group and the other acyl group (such as the acetyl group) in the polyvinyl alcohol resin , &Quot; degree of acetacetylation &quot; When the degree of acetacetylation in the polyvinyl alcohol-based resin is less than 0.1 mol%, the effect of improving the water resistance of the adhesive layer tends to be insufficient. The degree of acetacetylation in the polyvinyl alcohol-based resin is preferably about 0.1 to 40 mol%, more preferably 1 to 20 mol%, particularly preferably 2 to 7 mol%. When the degree of acetacetylation exceeds 40 mol%, the effect of improving the water resistance tends to be small.

The anion-denatured polyvinyl alcohol-based resin has an anionic group, typically a carboxyl group (-COOH) or a salt thereof in addition to the hydroxyl group constituting the polyvinyl alcohol skeleton, and even if it has other acyl groups such as an acetyl group good. The anion-modified polyvinyl alcohol-based resin can be produced, for example, by copolymerizing an unsaturated monomer having an anionic group (typically a carboxyl group) with vinyl acetate followed by saponification. On the other hand, the cation-modified polyvinyl alcohol-based resin contains a cationic group, typically a tertiary amino group or a quaternary ammonium group, in addition to the hydroxyl group constituting the polyvinyl alcohol skeleton, and other acyl groups such as an acetyl group and the like You can have it. The cation-modified polyvinyl alcohol-based resin can be produced, for example, by copolymerizing an unsaturated monomer having a cationic group (typically, a tertiary amino group or a quaternary ammonium group) with vinyl acetate followed by saponification.

The adhesive to be used in the present invention may contain two or more kinds of modified polyvinyl alcohol resins as mentioned above and may also include unmodified polyvinyl alcohol resins such as completely or partially saponified polyvinyl acetate, And a vinyl alcohol-based resin.

Since the adhesive containing a polyvinyl alcohol-based resin as a main component is used in the form of an aqueous solution, the concentration thereof is preferably such that the polyvinyl alcohol-based resin is in the range of 1 to 20 parts by weight based on 100 parts by weight of water, And more preferably 1 to 15 parts by weight, more preferably 1 to 10 parts by weight, particularly 2 to 10 parts by weight. When the concentration of the polyvinyl alcohol-based resin in the aqueous solution is too small, the adhesiveness tends to be lowered. On the other hand, when the concentration is too large, the optical characteristics of the obtained polarizing plate tends to be lowered. The water used for the adhesive may be pure water, ultrapure water, tap water or the like and is not particularly limited, but pure water or ultrapure water is preferable from the viewpoint of maintaining the uniformity and transparency of the formed adhesive layer. Alcohol such as methanol or ethanol may be added to the aqueous adhesive solution.

The polyvinyl alcohol resin constituting the adhesive can be appropriately selected and used from commercially available products. Specific examples of the polyvinyl alcohol having a high degree of saponification include "PVA-117H" sold by Kuraray Co., Ltd. and "Goserinol NH-20" sold by Nippon Gosei Kagaku Kogyo Co., , "Acetacetyl group-modified polyvinyl alcohol," "Koshefima Z" series sold by Nippon Kasei Kagaku Kogyo Co., Ltd., anion-modified polyvinyl alcohol, and " "Kosei T-330" sold by Nippon Kasei Kagaku Kogyo Co., Ltd., cation-modified polyvinyl alcohol, and "K-318" and "KM- Quot; CM-318 "and" Kosepaima K-210 "sold by Nippon Kasei Kagaku Kogyo Co., Ltd. (all trade names).

A water-based adhesive containing a polyvinyl alcohol-based resin as a main component may contain a crosslinking agent. The cross-linking agent may be a compound containing a functional group having reactivity with the polyvinyl alcohol-based resin, and any of those conventionally used in a polyvinyl alcohol-based adhesive may be used without particular limitation. For example, an isocyanate compound having at least two isocyanato groups (-NCO) in the molecule; An epoxy compound having at least two epoxy groups in the molecule; Mono- or di-aldehydes; An organic titanium compound; Magnesium, calcium, iron, nickel, zinc and aluminum; Metal salts of glyoxylic acid; Methylol melamine and the like.

Specific examples of the isocyanate compound as a crosslinking agent include tolylene diisocyanate, hydrogenated tolylene diisocyanate, adduct of trimethylolpropane and tolylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, Keto oxime block water or phenol block water.

Specific examples of the epoxy compound to be a crosslinking agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, di- or tri-glycidyl ether of glycerin, 1,6-hexanediol diglycidyl ether, trimethyl A water-soluble polyamide epoxy resin obtained by reacting polyamide polyamine, which is a reaction product of polyalkylene polyamine and dicarboxylic acid, with epichlorohydrin, and the like, which are obtained by reacting propylene glycol diol, oligo propane triglycidyl ether, diglycidyl aniline, diglycidyl amine, .

Specific examples of the monoaldehydes to be crosslinking agents include formaldehyde, acetaldehyde, propionaldehyde and butylaldehyde. Specific examples of dialdehydes include glyoxal, marondialdehyde, succindialdehyde, glutaraldaldehyde, Malaldehyde, phthalaldehyde, and the like.

As the organic titanium compound to be used as a crosslinking agent, various products are available from Matsumoto Fine Chemical Co., Ltd. (Search on November 16, 2011) of the company's organic titanium compound (Internet <URL: http: //www.m-chem.co.jp/products/products1.html>). Soluble titanium compound, the chemical formula of the water-soluble organic titanium compound, the chemical formula of the compound, the product name of the compound, and the like.

_{[(CH 3) 2 CHO]} 2 Ti [OCH 2 CH 2 N (CH 2 CH 2 OH) 2] 2: Chemical name company speak "titanium di-isopropoxy-bis (triethanol amino sulfonate)" The company's trade name "Olga Chicks TC-400 &quot;,&quot;

(HO) ₂ Ti [OCH (CH ₃ ) COO ^- ] ₂ (NH ₄ ⁺ ) ₂ : The chemical name "titan lactate ammonium salt"

(HO) ₂ Ti [OCH (CH ₃ ) COOH] ₂ : The chemical name "titan lactate" which the company refers to, the trade names "Olga Chicks TC-310" and "Olga Chicks TC-315".

The metal salt of the glyoxylic acid is preferably an alkali metal salt or an alkaline earth metal salt, and examples thereof include sodium glyoxylate, potassium glyoxylate, magnesium glyoxylate and calcium glyoxylate.

Among these crosslinking agents, epoxy compounds including the above-mentioned water-soluble polyamide epoxy resin, and alkali metal or alkaline earth metal salts of aldehydes, methylol melamine, and glyoxylic acid are suitably used.

The crosslinking agent is preferably dissolved in water together with the polyvinyl alcohol-based resin to form an adhesive. However, as described below, the amount of the crosslinking agent in the aqueous solution may be small, so that it may be used as a crosslinking agent if it has a solubility of at least about 0.1% by weight, for example, in water. Of course, a compound having solubility in water to such an extent that it is generally referred to as water-soluble is suitable as a crosslinking agent for use in the present invention.

The blending amount of the crosslinking agent is appropriately designed according to the kind of the polyvinyl alcohol-based resin, and is usually about 5 to 60 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the polyvinyl alcohol-based resin. When a cross-linking agent is blended in this range, good adhesion can be obtained. As described above, in order to improve the durability of the adhesive layer, an acetacetyl group-modified polyvinyl alcohol-based resin is preferably used. In this case, the cross-linking agent is added to 100 parts by weight of the polyvinyl alcohol- By weight, more preferably 10 to 50 parts by weight. If the blending amount of the crosslinking agent is excessively large, the crosslinking reaction of the adhesive proceeds in a short time, and the adhesive tends to gel early, so that the pot life is extremely shortened, making industrial use difficult.

The adhesives may be blended with conventionally known additives such as silane coupling agents, plasticizers, antistatic agents, and fine particles, as long as they do not impair the effects of the present invention.

When a urethane resin is used as a main component of the water-based adhesive, a mixture of a polyester-based ionomer-type urethane resin and a compound having a glycidyloxy group can be given as an example of a suitable adhesive. The polyester-based ionomer-type urethane resin referred to here is a urethane resin having a polyester skeleton, and a small amount of an ionic component (hydrophilic component) is introduced into the urethane resin. Such an ionomeric urethane resin emulsifies directly in water without using an emulsifier, so that the emulsion is suitably used for an aqueous adhesive. The use of a polyester-based ionomeric urethane resin as an adhesive for a polarizing film and a protective film is disclosed, for example, in JP-A-2005-070140, JP-A-4432487 (= Open Publication No. 2005-208456.

A curable adhesive containing an active energy ray-curable compound may be used for adhesion between the polarizing film 42 and the second retardation film 18 made of the protective film 44 and / or the cycloolefin-based resin film. The term &quot; active energy ray-curable compound &quot; means a compound that can be cured by irradiation with an active energy ray. The active energy ray-curable compound may be cationically polymerized or radically polymerized. Examples of the cationic polymerizable compound include an epoxy compound having at least one epoxy group in the molecule, and an oxetane compound having at least one oxetane ring in the molecule. Examples of the radically polymerizable compound include (meth) acrylic compounds having at least one (meth) acryloyloxy group in the molecule.

The active energy ray curable compound used in this adhesion preferably contains at least an epoxy compound and accordingly it is preferable that the active energy ray curable compound to be used for the adhesion has a good balance between the polarizing film 42 and the second retardation plate 18 made of a cycloolefin- Thereby exhibiting adhesion. When the protective film 44 is formed of a cellulose acetate resin film, the active energy ray curable adhesive containing the epoxy compound as a curable component exhibits good adhesion between the protective film 44 and the polarizing film 42.

From the viewpoints of weather resistance, refractive index, cationic polymerizability, and the like, it is preferable that the epoxy compound is composed mainly of an epoxy compound which does not contain an aromatic ring in the molecule. Examples of the epoxy compound which does not contain an aromatic ring in the molecule include glycidyl ether of a polyol having an alicyclic ring, aliphatic epoxy compound, and alicyclic epoxy compound. The epoxy compound suitably used for such an active energy ray-curable adhesive is described in detail in, for example, Japanese Patent No. 306270 (= Japanese Patent Application Laid-Open No. 2004-245925).

The glycidyl ether of a polyol having an alicyclic ring may be a glycidyl etherified nucleus-hydrogenated polyhydroxy compound obtained by subjecting an aromatic polyol to a selective hydrogenation reaction to an aromatic ring under pressure in the presence of a catalyst . Examples of the aromatic polyol include bisphenol-type compounds such as bisphenol A, bisphenol F and bisphenol S; Novolak type resins such as phenol novolak resins, cresol novolac resins and hydroxybenzaldehyde phenol novolac resins; Polyfunctional type compounds such as tetrahydroxydiphenylmethane, tetrahydroxybenzophenone and polyvinylphenol, and the like. Glycidyl ether can be obtained by reacting epichlorohydrin with an alicyclic polyol obtained by hydrogenating an aromatic ring of these aromatic polyols. Among the glycidyl ethers of polyols having alicyclic rings, diglycidyl ethers of hydrogenated bisphenol A are particularly preferred.

The aliphatic epoxy compound may be a polyglycidyl ether of an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof. More specifically, diglycidyl ether of 1,4-butanediol; Diglycidyl ether of 1,6-hexanediol; Triglycidyl ether of glycerin; Triglycidyl ether of trimethylolpropane; Diglycidyl ether of polyethylene glycol; Diglycidyl ether of propylene glycol; And polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide or propylene oxide) to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol or glycerin.

The alicyclic epoxy compound is a compound having at least one epoxy group bonded to an alicyclic ring in the molecule. Here, the "epoxy group bonded to an alicyclic ring" means a bridging oxygen atom -O- in the structure represented by the following formula (III), wherein n is an integer of 2 to 5.

(III)

(III)

A compound in which one or more hydrogen atoms of the group (CH ₂ ) _n in the formula (III) is removed from the group bonded to another chemical structure may be an alicyclic epoxy compound. Further, one or a plurality of hydrogen atoms in (CH ₂ ) _n forming an alicyclic ring may be appropriately substituted with a straight chain alkyl group such as a methyl group or an ethyl group.

Among the above epoxy compounds, an alicyclic epoxy compound, that is, a compound having at least one epoxy group bonded to an alicyclic ring is preferable, and an oxabicyclohexane ring [in the formula (III) where n = 3 ] Or an oxabicycloheptane ring [wherein n = 4 in the formula (III)] has a high modulus of elasticity of the cured product and gives good adhesion between the polarizing film and the protective film, . Specific examples of the alicyclic epoxy compound are given below. Here, the compound names are given first, and then the corresponding chemical formulas are shown, and the chemical names and corresponding chemical names are given the same reference numerals.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-

B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate,

C: Ethylene bis (3,4-epoxycyclohexanecarboxylate),

D: bis (3,4-epoxycyclohexylmethyl) adipate,

E: bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate,

F: diethylene glycol bis (3,4-epoxycyclohexylmethyl ether),

G: ethylene glycol bis (3,4-epoxycyclohexylmethyl ether),

H: 2,3,14,15-diepoxy-7,11,18,21-tetraoxatrispyro [5.2.2.5.2.2] heneic acid,

I: 3- (3,4-epoxycyclohexyl) -8,9-epoxy-1,5-dioxaspiro [5.5] undecane,

J: 4-vinylcyclohexene dioxide,

K: limonene dioxide,

L: bis (2,3-epoxycyclopentyl) ether,

M: dicyclopentadiene dioxide and the like.

In the active energy ray-curable adhesive, only one epoxy compound may be used alone, or two or more epoxy compounds may be used in combination.

The active energy ray-curable adhesive may contain an oxetane compound in addition to the above epoxy compound. By adding the oxetane compound, the viscosity of the adhesive can be lowered and the curing rate can be increased.

The oxetane compound is a compound having at least one oxetane ring (4-membered ring ether) in the molecule, and examples thereof include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis [ (3-ethyl-3-oxetanyl) methyl] ether, 3-ethyl-3- Hexyloxymethyl) oxetane, phenol novolac oxetane, and the like. The blending amount of the oxetane compound is generally 50% by weight or less, preferably 10 to 40% by weight based on the total amount of the active energy ray-curable compound. The oxetane compounds are commercially available products such as "AARON oxetane OXT-101", "AARON oxetane OXT-121", "AORON oxetane OXT- Oxetane OXT-211 "," aronoxetane OXT-221 "and" aronoxetane OXT-212 ".

When the active energy ray-curable adhesive contains a cationic polymerizable compound such as an epoxy compound or an oxetane compound, the adhesive is usually compounded with a photocationic polymerization initiator. The use of a photocationic polymerization initiator makes it possible to form an adhesive layer at room temperature, so that it is possible to reduce the need to consider distortion due to heat resistance and expansion of the polarizing film, and to bond the polarizing film and the protective film with good adhesion. In addition, since the photocationic polymerization initiator acts catalytically with light, the above-mentioned adhesive mixed with the photocationic polymerization initiator is excellent in storage stability and workability.

The cationic ionic polymerization initiator generates a cationic species or a Lewis acid by irradiation of an active energy ray such as visible light, ultraviolet ray, X-ray or electron beam to initiate the polymerization reaction of the cationic polymerizable compound. Any kind of photocatalytic ion polymerization initiator may be used, and specific examples thereof include aromatic diazonium salts; Onium salts such as aromatic iodonium salts and aromatic sulfonium salts; Iron-arene complexes and the like.

Examples of the aromatic diazonium salt include the following compounds.

Benzene diazonium hexafluoroantimonate, benzene diazonium hexafluoroantimonate,

Benzene diazonium hexafluorophosphate,

Benzene diazonium hexafluoroborate and the like.

Examples of the aromatic iodonium salt include the following compounds.

Diphenyl iodonium tetrakis (pentafluorophenyl) borate,

Diphenyl iodonium hexafluorophosphate,

Diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate,

Di (4-nonylphenyl) iodonium hexafluorophosphate, and the like.

Examples of the aromatic sulfonium salts include the following compounds.

Triphenylsulfonium hexafluorophosphate,

Triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate,

Triphenylsulfonium tetrakis (pentafluorophenyl) borate,

4,4'-bis (diphenylsulfono) diphenylsulfide bis hexafluorophosphate,

4,4'-bis [di (? - hydroxyethoxy) phenylsulfonio] diphenylsulfide bis hexafluoroantimonate,

4,4'-bis [di (? - hydroxyethoxy) phenylsulfonio] diphenylsulfide bis hexafluorophosphate,

7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate,

7- (di (p-toluyl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate,

4-phenylcarbonyl-4'-diphenylsulfone-diphenylsulfide hexafluorophosphate,

4- (p-tert-butylphenylcarbonyl) -4'-diphenylsulfonio-diphenylsulfide hexafluoroantimonate,

4- (p-tert-butylphenylcarbonyl) -4'-di (p-toluyl) sulfonio-diphenylsulfide tetrakis (pentafluorophenyl) borate and the like.

Examples of the iron-arene complexes include the following compounds.

Xylene-cyclopentadienyl iron (II) hexafluoroantimonate,

Cumene-cyclopentadienyl iron (II) hexafluorophosphate,

Xylene-cyclopentadienyl iron (II) tris (trifluoromethylsulfonyl) methanide, and the like.

These cationic ion polymerization initiators can be easily obtained from commercial products. Examples thereof include "Kayarad PCI-220" and "Kayarad PCI-620" sold by Nippon Kayaku Co., Ltd., Union Carbide Co., "UVACURE 1590" sold by Daicel-Cytech Co., Ltd., "Adeka Optoma SP-150" and "Adeka Optoma SP- CIP-2064S "and" CIP-2064S "sold by Nippon Soda Co., Ltd.," CI-5102 "," CIT-1370 "," CIT- DPI-101 "," DPI-102 "," DPI-103 "," DPI-105 "," MPI-103 "," MPI- "TPS-103", "TPS-105", "MDS-103", "MDS-102", "BBI-102", "BBI-103", "BBI-105" -105 "," DTS-102 "and" DTS-103 ", and" PI-2074 "sold by Rhodia.

These photo cationic polymerization initiators may be used alone or in combination of two or more. Among them, in particular, an aromatic sulfonium salt has an ultraviolet ray absorbing property even in a wavelength range of 300 nm or more, and thus gives a cured product having excellent curability, good mechanical strength and good adhesion between a polarizing film and a protective film It is preferably used.

The blending amount of the photocationic polymerization initiator is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, based on 100 parts by weight of the total amount of the cationic polymerizable compound including an epoxy compound and an oxetane compound. When the blending amount of the photocationic polymerization initiator is small, the curing becomes insufficient, and the mechanical strength and the adhesion between the polarizing film and the protective film tend to be lowered. On the other hand, if the compounding amount of the photocationic polymerization initiator is too large, the amount of the ionic substance in the cured product increases, so that the hygroscopic property of the cured product is increased, and the durability of the resulting adhesive layer may be lowered.

Further, the active energy ray-curable adhesive may contain, together with the above epoxy compound or epoxy compound and oxetane compound, a (meth) acrylic compound which is subjected to radical polymerization. (Meth) acrylic compound is used in combination, the effect of increasing the hardness and mechanical strength of the adhesive layer can be expected, and further, the viscosity and the curing speed of the curable adhesive can be further easily adjusted. Examples of such (meth) acrylic compounds include the same as the above-mentioned active energy ray curable resin composition for forming the adhesive layer.

The adhesive constituting the second adhesive layer 32 and / or the third adhesive layer 33 may contain optional components as required. Examples of such optional components include those described above as components which can be blended in the curable resin composition constituting the adhesive layer 31 for adhering the first retardation plate 10 and the second retardation plate 18 .

[Liquid crystal display panel and liquid crystal display device]

The composite polarizing plate 50 of the present invention constituted as described above is constituted of a pressure sensitive adhesive layer formed on the surface opposite to the surface of the compound retardation film 20 adhered to the polarizing film 42, Layer 46 to the liquid crystal cell to form a liquid crystal display panel. This liquid crystal panel is combined with a backlight to form a liquid crystal display device. In the configuration shown in Fig. 2, the separator 48 formed on the surface of the pressure-sensitive adhesive layer 46 is peeled off before bonding to the liquid crystal cell. A liquid crystal panel may be constituted by disposing the complex polarizer 50 of the present invention on both sides of the liquid crystal cell or by arranging the complex polarizer 50 of the present invention on one side of the liquid crystal cell. In the latter case, a separate polarizing plate is generally disposed on the surface of the liquid crystal cell where the composite polarizing plate 50 of the present invention is not disposed. The liquid crystal display panel and the liquid crystal display device having such a configuration are particularly effective when the liquid crystal cell is in the transverse electric field (IPS) mode.

In the liquid crystal panel and the liquid crystal display device described above, when the composite polarizing plate 50 of the present invention is disposed on one surface of the liquid crystal cell, the transparent protective film, which becomes the liquid crystal cell side of the polarizing plate disposed on the other surface, It is preferable that the in-plane retardation (Re) is 10 nm or less and the absolute value of the retardation (Rth) in the thickness direction is 15 nm or less. More preferably, the in-plane retardation (Re) is 5 nm or less and the absolute value of the retardation (Rth) in the thickness direction is 10 nm or less.

Examples of the material for use in the transparent protective film having an in-plane retardation (Re) of 10 nm or less and an absolute value of a retardation (Rth) in the thickness direction of 15 nm or less include cellulose resins, cyclic olefin resins, (meth) Polyethylene terephthalate resin, and polypropylene resin. In the film made of these resins, those having a small retardation in the in-plane direction and in the thickness direction may be appropriately selected and used.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In the examples,% and parts representing the content or amount are based on the weight unless otherwise specified. The retardation and the Nz coefficient of the film are values measured at a wavelength of 590 nm. First, a production example of a first retardation plate having a (meth) acrylic resin layer is described.

[Production Example 1] Production of a first retardation plate having a methacrylic resin layer

The styrene-maleic anhydride copolymer resin having a glass transition temperature of 131 DEG C was used as the resin for the phase difference developing layer 12, which was sold under the trade name of "DAIRAQUE D332" by NOVA CHEMICAL. The resin used as the (meth) acrylic resin layer 14, 15 is used for "Technoloy S001" sold by Sumitomo Chemical Co., Ltd. and contains about 20% of acrylic rubber particles having an average particle diameter of 200 μm Methacrylic resin having a glass transition temperature of 105 占 폚 was used. Then, the three layers co-extruded so as to form a methacrylic resin layer on both sides of the layer made of the styrene-maleic anhydride copolymer resin, and the thickness of the layer made of the styrene-maleic anhydride copolymer resin was 80 m, And a thickness of the methacrylic resin layer formed on both surfaces thereof was 40 mu m, respectively. This three-layered resin film was stretched so that the thickness of the retardation developing layer 12 was 40 占 퐉 and the thickness of the methacrylic resin layers 14 and 15 was 20 占 퐉 and the total thickness was 80 占 퐉, . This retardation plate had an in-plane retardation of 47.3 nm and an Nz coefficient of -1.06.

Next, a production example of an adhesive made of a curable resin composition used for adhering the above-prepared first retardation plate to a second retardation plate made of a cycloolefin-based resin film is described.

[Preparation Example 2] Preparation of curable resin composition A

Methyl-1- [4- (methylthio) phenyl] acrylamide, methyl acrylate, sold under the trade name "Irgacure 907" by BASF, 2-morpholinopropane-1-one, and a silicone leveling agent sold under the trade name "SH710 " by Dow Corning Co., Ltd. were mixed in the following proportions to obtain a curable resin composition A It was prepared. The above-mentioned "Irgacure 907" is abbreviated as " photo radical polymerization initiator "Irgacure 907 ". The above-mentioned "SH710" is abbreviated as "silicone leveling agent" SH710 ".

Curable resin composition A

N- (2-hydroxyethyl) acrylamide 80 parts

Methyl acrylate 20 parts

Photoradical polymerization initiator "Irgacure 907" Part 3

Silicon leveling agent "SH710" 0.2 part

[Production Examples 3 and 4] Preparation of curable resin compositions B and C

The curable resin compositions B and C were prepared in the same manner as in Production Example 2 except that the mixing ratio of N- (2-hydroxyethyl) acrylamide and methyl acrylate was changed as follows.

Curable resin composition B

N- (2-hydroxyethyl) acrylamide 70 parts

Methyl acrylate 30 parts

Photoradical polymerization initiator "Irgacure 907" Part 3

Silicon leveling agent "SH710" 0.2 part

Curable resin composition C

N- (2-hydroxyethyl) acrylamide 60 parts

Methyl acrylate 40 parts

Photoradical polymerization initiator "Irgacure 907" Part 3

Silicon leveling agent "SH710" 0.2 part

[Preparation Example 5] Preparation of curable resin composition X

The curable resin composition X was prepared in the same manner as in Production Example 2 except that methyl acrylate was not used and the amount of N- (2-hydroxyethyl) acrylamide was changed to 100 parts. The blending amount of the curable resin composition X is as follows.

Curable resin composition X

N- (2-hydroxyethyl) acrylamide 100 parts

Photoradical polymerization initiator "Irgacure 907" Part 3

Silicon leveling agent "SH710" 0.2 part

[Preparation Example 6] Preparation of curable resin composition Y

Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, which is sold under the trade name "Suloxide 2021P " by Dai-ichi Kagaku Co., Ltd., and 3,4-epoxycyclohexylmethyl 3,4- Oxetane compound sold under the trade name AARON OXETHANE OXT-221 ", the chemical name is bis (3-ethyl-3-oxetanylmethyl) ether, trade name "UVACURE 1590 " (Diphenylsulphonio) diphenyl sulfide bishexafluorophosphate based light cation polymerization initiator and silicone leveling agent "SH710" which are commercially available from Nippon Synthetic Chemical Industry Co., Ltd. are mixed at the following ratios to prepare a curable resin composition X was prepared. The above-mentioned " Suloxide 2021P "is abbreviated as " Epoxy Compound" Suloxide 2021P ", and abbreviated as " CEL 2021P " The above-mentioned "Aromon oxetane OXT-221" is abbreviated as "Oxetane compound" Aromon oxetane OXT-221 "and abbreviated as" OXT-221 "in the table. The above-mentioned "UVACURE 1590" is abbreviated as &quot; UVACURE 1590 &quot;

Curable resin composition Y

Epoxy Compound "Suloxide 2021P" 75 parts

Oxetane compound "Aronoxetane OXT-221" 25 parts

Gwangyang Ion Polymerization Initiator "UVACURE 1590" 5 parts

Silicon leveling agent "SH710" 0.2 part

Next, examples in which a composite retardation plate was produced by bonding the second retardation plate made of a cycloolefin-based resin to the first retardation plate produced in Production Example 1 using the curable resin compositions prepared in Production Examples 2 to 6 and A comparative example is shown.

[Example 1]

Plane retardation = 90 nm, thickness direction retardation = 79 nm) made of a stretched film of cycloolefine resin having a thickness of 25 mu m (Zeonoa film sold by Nippon Zeon Co., Ltd.) as a second retardation plate , And the curable resin composition A prepared in Production Example 2 was coated on one side thereof with a coating machine (bar coater manufactured by Dai-ichirika Co., Ltd.). Since the film thickness when the curable resin composition was coated changes depending on the viscosity, the number of the bar coater was changed and the film thickness after curing was adjusted to be 7 占 퐉. Then, on one surface of the first retardation plate prepared in Production Example 1, a cycloolefin resin film on which a coating film of the curable resin composition A described above was formed was placed so that the coating film side became an adhesive surface to the first retardation plate ("LPA3301" manufactured by Fuji Plasma Co., Ltd.). Ultraviolet rays were irradiated to the bonded product on the side of the cycloolefin based resin film using an ultraviolet irradiator equipped with a belt conveyor (lamp: "D bulb" manufactured by Fusion UV Systems Co., Ltd.) so that the accumulated light quantity was 250 mJ / And the curable resin composition was cured to prepare a composite retarder.

[Examples 2 and 3]

A composite retardation plate was fabricated by operating in the same manner as in Example 1, except that the curable resin composition was adjusted so as to have a film thickness after curing of 5 占 퐉 and 3 占 퐉.

[Examples 4 to 6]

Three types of compound phase difference plates having different adhesive layer thicknesses were produced by operating in the same manner as in Examples 1 to 3, respectively, except that the curable resin composition B prepared in Preparation Example 3 was used in place of the curable resin composition A.

[Examples 7 and 8]

Two types of compound retardation plates having different adhesive layer thicknesses were produced by the same procedures as in Examples 2 and 3 except that the curable resin composition C prepared in Production Example 4 was used in place of the curable resin composition A. [

[Comparative Examples 1 to 3]

Three types of compound retardation plates having different adhesive layer thicknesses were produced by operating in the same manner as in Examples 1 to 3, respectively, except that the curable resin composition X prepared in Production Example 5 was used in place of the curable resin composition A.

[Comparative Examples 4 to 6]

Three types of compound retardation plates having different adhesive layer thicknesses were produced by operating in the same manner as in Examples 1 to 3 except that the curable resin composition Y prepared in Preparation Example 6 was used in place of the curable resin composition A.

[Comparative Example 7]

A corona treatment was applied to one surface of a stretched cycloolefin-based resin film having a thickness of 25 占 퐉 which was the same as that used in Example 1, and an acrylic pressure-sensitive adhesive sheet having a thickness of 15 占 퐉 was bonded thereto. Further, a corona treatment was applied to one surface of the first retardation plate manufactured in Production Example 1, and the surface of the first retardation plate was bonded to the opposite surface of the acrylic pressure-sensitive adhesive to the oriented cycloolefin-based resin film to produce a composite retardation plate.

[Evaluation test of adhesive strength]

The surfaces of the cycloolefin resin films of the composite retardation plates produced in Examples 1 to 8 and Comparative Examples 1 to 7 were subjected to corona treatment and then the acrylic pressure sensitive adhesive sheet was bonded to the treated surface to obtain a composite retarder having an adhesive . A test piece having a width of 25 mm and a length of about 200 mm was cut from the compound retarder having the obtained pressure sensitive adhesive and the pressure sensitive adhesive surface was bonded to a soda glass and then pressed in an autoclave at a pressure of 5 kgf / Minute, followed by allowing to stand for one day in an atmosphere at a temperature of 23 캜 and a relative humidity of 60%.

In this state, using a universal tensile tester ("AG-1" manufactured by Shimadzu Seisakusho Co., Ltd.), a first retardation plate having a three-layer structure in one longitudinal end (one side with a width of 25 mm) JIS K 6854-1: 1999 "Adhesive-peel adhesion strength test method - Part 1: 90 degrees at a crosshead speed (grip moving speed) of 200 mm / min under an atmosphere of a temperature of 23 캜 and a relative humidity of 60% Peeling ", a 90 ° peeling test was conducted to evaluate the adhesive force between the first retardation plate including the methacrylic resin layer and the second retardation plate comprising the cycloolefin resin film. The results are shown in Table 1. In Table 1, the term &quot; material breakage &quot; in the &quot; adhesive force &quot; column indicates that in the above peeling test, the first retardation plate and the second retardation plate are not separated from each other in the adhesive layer, Or the layer of the second retarder plate is broken.

Yes No
Adhesive (Curable resin composition and its curable component) Film thickness
(탆) Adhesion
(N / 25 mm) sign HEAA MA CEL 2021P OXT-221 Example 1
A
80%

20%




7 Material destruction Example 2 5 Material destruction Example 3 3 Material destruction Example 4
B

70%

30%




7 Material destruction Example 5 5 Material destruction Example 6 3 Material destruction Example 7 C
60%
40%


5 1.5 Example 8 3 1.0 Comparative Example 1 X


100%

-




7 0.5 Comparative Example 2 5 0.4 Comparative Example 3 3 0.3 Comparative Example 4 Y






75%

25%
7 0.4 Comparative Example 5 5 0.3 Comparative Example 6 3 0.4 Comparative Example 7 (Acrylic adhesive) 15 10.0

(footnote)

HEAA: N- (2-hydroxyethyl) acrylamide

MA: methyl acrylate

CEL 2021P: epoxy compound "Suloxide 2021P"

OXT-221: oxetane compound "AARON oxetane OXT-221"

As shown in Table 1, by adhering the first retardation plate and the second retardation plate using an adhesive containing a mixture of N- (2-hydroxyethyl) acrylate and methyl acrylate as a curable component, , The adhesive strength can be improved. On the other hand, when an adhesive containing a mixture of an epoxy compound and an oxetane compound as a curable component is used for adhesion between the first retardation plate and the second retardation plate (Comparative Examples 4 to 6), sufficient adhesion can not be obtained.

10: first retardation plate,
12: phase difference developing layer,
14, 15: a (meth) acrylic resin layer,
18: a second retardation plate,
20: Composite retarder,
31: adhesive layer,
32: second adhesive layer,
33: third adhesive layer,
42: polarizing film,
44: protective film,
46: pressure-sensitive adhesive layer,
48: Separator,
50: Composite polarizer.

Claims (11)

(Meth) acryl-based resin layer of a first retardation plate having a (meth) acrylic resin layer on its outermost surface, an adhesive layer comprising a cured product of an active energy ray-curable resin composition and a second retardation film comprising a cycloolefin- Are stacked in this order,
The active energy ray-curable resin composition contains N-substituted (meth) acrylamide and a compound having a (meth) acryloyloxy group in the molecule as a curing component,
Wherein the adhesive layer has a thickness of 10 占 퐉 or less. The composition according to claim 1, wherein the N-substituted (meth) acrylamide is a compound retarder represented by the following formula (I)

(I)
(Wherein Q ₁ represents a hydrogen atom or a methyl group, Q ₂ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Q ₃ represents an alkyl group having 1 to 6 carbon atoms which may have a hydroxyl group, or Q ₂ and Q ₃ together form a 5-membered ring or a 6-membered ring which may be taken together with the nitrogen atom to which they are bonded and the oxygen atom as a ring member) The compound having a (meth) acryloyloxy group according to claim 1 or 2, wherein the compound is an alkyl (meth) acrylate represented by the following formula (II):

(II)
(Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group having 1 to 6 carbon atoms) The active energy ray-curable resin composition according to claim 1, wherein the active energy ray-curable resin composition contains 60 to 80% by weight of N-substituted (meth) acrylamide represented by the following formula (I) (Meth) acrylate represented by the following general formula (II): 40 to 20 wt%

(I)
(Wherein Q ₁ represents a hydrogen atom or a methyl group, Q ₂ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Q ₃ represents an alkyl group having 1 to 6 carbon atoms which may have a hydroxyl group, or Q ₂ and Q ₃ together form a 5-membered ring or a 6-membered ring which may be taken together with the nitrogen atom to which they are bonded and the oxygen atom as a ring member)

(II)
(Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group having 1 to 6 carbon atoms) The composite retarder according to any one of claims 1 to 4, wherein the first retardation plate comprises a retardation-developing layer made of another resin in addition to the (meth) acrylic resin layer. 6. The compound retarder according to claim 5, wherein the retardation developing layer has a glass transition temperature of 120 DEG C or higher and the (meth) acrylic resin layer has a glass transition temperature of 120 DEG C or lower. The composite retarder according to claim 5 or 6, wherein the retardation-developing layer is made of a styrene-based resin. The composite retarder according to any one of claims 5 to 7, wherein the (meth) acrylic resin layer contains rubber particles. The compound retarder according to any one of claims 5 to 8, wherein the first retardation plate is formed by forming the (meth) acrylic resin layer on both surfaces of the retardation developing layer. The composite retarder according to claim 9, wherein the phase difference-generating layer and the (meth) acrylic resin layer formed on both sides thereof have a thickness of 10 to 100 탆. A protective film made of a thermoplastic resin is laminated on one side of a polarizing film on which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol based resin through a second adhesive layer and on the other side of the polarizing film, Wherein the composite retardation film according to any one of claims 1 to 10 is laminated on the side of the cycloolefin based resin film through an adhesive layer.

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