TWI570454B - Composite phase difference plate and composite polarizing plate using the same - Google Patents

Description

Composite phase difference plate and composite polarizing plate using the same

The present invention relates to a phase difference plate having a (meth)acrylic resin layer and a phase difference plate comprising a cycloolefin resin film (in the present disclosure, "..." also means "including The composite phase difference plate which is laminated and which is suitable for use in a liquid crystal display device, and a composite phase difference plate which is obtained by combining the composite phase difference plate and a polarizing plate.

The liquid crystal display device is used in various display devices because it consumes less power, operates at a low voltage, is lightweight, and is thin. The liquid crystal display device is composed of a plurality of materials such as a liquid crystal cell, a polarizing plate, a phase difference plate, a light collecting sheet, a diffusion film, a light guiding plate, and a light reflecting sheet. Therefore, improvement in productivity, weight reduction, brightness improvement, and the like has been progressing by reducing the number of sheets constituting the film or thinning the thickness of the film or sheet.

The phase difference plate is usually produced by stretching a resin film. The main chain of the resin is extended to conform to the axis of extension, but the resin having no bulky chain in the side chain has a maximum refractive index in the direction of the axis of extension, and its direction is a slow axis. Such a resin is referred to as a resin having a positive refractive index anisotropy, and a phase difference plate formed of the resin is also referred to as a positive phase difference plate. Recently, positive phase difference A stretched film of a cycloolefin-based resin having a small photoelastic coefficient is often used for the sheet. On the other hand, the side chain has a bulky resin, and since the side chain direction, that is, the refractive index in the direction orthogonal to the extension axis, is maximized, the direction of the extension axis becomes a fast axis. Such a resin is referred to as a resin having a negative refractive index anisotropy, and a phase difference plate formed of the resin is also referred to as a negative phase difference plate. A resin having a negative refractive index anisotropy has been known since ancient times as a styrene resin having styrene as a main constituent unit or a (meth)acrylic resin having acrylate or methacrylate as a main constituent unit.

The (meth)acrylic resin has a small phase difference in developability. On the other hand, although the styrene-based resin has a large phase difference, it has disadvantages such as chemical resistance and mechanical strength. Therefore, we also try to combine the two. For example, Japanese Patent No. 4770176 (Patent Document 1) discloses that a double-sided co-extrusion of a first layer composed of a styrene resin is composed of a (meth)acrylic resin layer. The resin layered film was laminated on the second layer of the composition, and the resin multilayer film was stretched to provide an in-plane retardation to form a phase difference plate. Japanese Laid-Open Patent Publication No. 2009-175222 (Patent Document 2) discloses that a retardation film composed of the resin multilayer film disclosed in Patent Document 1 is laminated on a polarizing film via an adhesive layer to form a composite polarizing plate. When the undercoat layer is interposed between the phase difference plate and the adhesive layer, the adhesion between the two is improved.

Further, from the viewpoint of optical compensation, a phase difference plate suitable for a liquid crystal display device can be used by laminating two or more films. At this time, generally, from the viewpoint of workability, an adhesive composed of an acrylic resin can be used for the film. Japanese Patent Publication No. 2010-217870 (Patent Document 3) discloses a first phase difference plate composed of an olefin resin containing a cycloolefin resin as a representative example. The second phase difference plate composed of the three-layer structure disclosed in Patent Document 1 is laminated on the first phase difference plate side via the adhesive layer, and is laminated on the polarizing film via the adhesive layer on the first phase difference plate side. To make a composite polarizer.

On the other hand, it is also known that two types of adherends are adhered by an adhesive which is cured by irradiation with an active energy ray of ultraviolet light as a representative example. For example, Japanese Patent No. 2805225 (Patent Document 4) discloses that the molded article of the cycloolefin resin is bonded to each other, or the molded article and the material different therefrom are bonded to each other. A method in which a monomer or a reactive oligomer is bonded to an ultraviolet curable adhesive of a photopolymerization initiator, and then irradiated with ultraviolet rays to cure the adhesive. In JP-A-2005-62443 (Patent Document 5), an adhesive made of an acrylic ultraviolet curable resin is used, and a transparent substrate made of glass as a representative example and an organic compound such as a cycloolefin resin are used. The retardation film composed of the polymer material is bonded, and the adhesive is cured by ultraviolet irradiation, and the thickness of the adhesive layer is 10 μm or less.

When the adhesive disclosed in the above Patent Document 3 is used for bonding the cycloolefin resin film to the (meth)acrylic resin film, in order to maintain an appropriate adhesive force, a thickness of the adhesive layer of at least about 15 μm is required. It has become a bottleneck in the reduction in thickness of a liquid crystal panel or a liquid crystal display device. In addition, when the adhesive layer is thinned, when the cycloolefin resin film and the (meth)acrylic resin film are bonded together with an adhesive having a thickness of 10 μm or less, the adhesion is insufficient, and the laminate is insufficient. The phase difference plate itself, the composite polarizing plate in which the laminated phase difference plate is bonded to the polarizing film, or the liquid crystal panel in which the composite polarizing plate is bonded to the liquid crystal cell glass is exposed to a high temperature, Fully absorb the shrinkage of the film, sometimes in the film and adhesive layer There are problems such as floating, peeling, foaming, and the like.

In addition, it is also possible to use an acrylic ultraviolet curable resin as an adhesive for bonding a cycloolefin resin film and a (meth)acrylic resin film, and it is cured by ultraviolet irradiation, but it is commercially available separately. It is also difficult to obtain a sufficient adhesion force in the acrylic ultraviolet curable resin.

The problem of the present invention is to laminate a phase difference plate made of a cycloolefin resin film on the (meth)acrylic resin layer having a retardation plate of a (meth)acrylic resin layer on the outermost surface. When the composite retardation film is formed, the adhesion between the (meth)acrylic resin layer and the cycloolefin resin is increased while the film thickness is 10 μm or less.

Another object of the present invention is to provide a composite polarizing plate in which a polyvinyl alcohol-based resin adsorbs a surface of a polarizing film having a dichroic dye, and the composite phase difference plate obtained as described above is bonded thereto. The adhesion of each layer is sufficient, and at the same time, the thinner is sought.

As a result of the investigation, it has been found that when a combination of two specific types of (meth)acrylic compounds is used as a curable component to form an active energy ray-curable resin composition, and this is used as an adhesive, it can be used in (meth) The present invention is completed by obtaining a high adhesion between the acrylic resin film and the cycloolefin resin film.

That is, according to the present invention, it is possible to provide a composite phase difference plate which is attached to the (meth)acrylic resin layer having the first phase difference plate of the (meth)acrylic resin layer on the outermost surface, in order An adhesive layer comprising a cured product of an active energy ray-curable resin composition and a second retardation film comprising a cycloolefin-based resin film, wherein the active energy ray-curable resin composition contains N-substituted (meth) acrylamide and a compound having a (meth) propylene oxime group in the molecule as a hardening The above-mentioned adhesive layer has a thickness of 10 μm or less.

In the composite phase difference plate, the N-substituted (meth) acrylamide which is a curable component constituting the active energy ray-curable resin composition is preferably a compound represented by the following formula (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, and 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 with the nitrogen atom to which the bond is bonded, a 5-membered ring or a 6-membered ring which may have an oxygen atom as a ring constituent member is formed.

Further, the compound having a (meth)acryloxy group in the molecule which is another curable component constituting the active energy ray-curable resin composition is preferably an alkyl (meth)acrylate represented by the following formula (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 preferably contains 60 to 80% by weight of N-substituted (meth) acrylamide and (meth) propylene oxime in the molecule, based on the total amount of the curable component. The compound is based on 40 to 20% by weight. Further, when a combination of the N-substituted (meth) acrylamide represented by the above formula (I) and the alkyl (meth) acrylate represented by the above formula (II) is used, the above formula is preferably also contained ( I) 60 to 80% by weight of N-substituted (meth) acrylamide, and (meth) represented by the above formula (II) The alkyl acrylate is 40 to 20% by weight.

In the composite retardation film, the first retardation film may be composed of a single film of a (meth)acrylic resin, but may be composed of another resin in addition to the (meth)acrylic resin layer. The phase difference is formed by a laminated film of the layer. In this case, the second retardation film composed of the cycloolefin-based resin film is bonded to the (meth)acrylic resin layer via the above-described active energy ray-curable resin composition. Therefore, when the first retardation film is composed of the laminated film, the (meth)acrylic resin layer is adhered to the outermost surface of the cycloolefin-based resin film.

When the first phase difference plate is composed of the laminated film as described above, the (meth)acrylic resin layer generally has a glass transition temperature of 120 ° C or lower, but the phase difference display layer is preferably a glass transition having a temperature of 120 ° C or higher. Temperature resin composition. From the viewpoint of producing a resin which achieves such a high glass transition temperature and at the same time has a negative refractive index anisotropy, the phase difference display layer is preferably made of a styrene resin. Moreover, it is advantageous from a viewpoint of film-film-forming property that a (meth)acrylic-type resin layer contains rubber particle.

The first retardation film is particularly advantageous in that the three-layer structure of the (meth)acrylic resin layer is formed on both surfaces of the phase difference display layer. In this case, the phase difference display layer and the (meth)acrylic resin layer formed on both sides thereof may have respective thicknesses in the range of about 10 to 100 μm.

Further, according to the present invention, it is also possible to provide a composite polarizing plate in which a polyvinyl alcohol-based resin adsorbs one side of a polarizing film having a dichroic dye, and is laminated with a thermoplastic resin via a second adhesive layer. The protective film is formed on the other side of the polarizing film, and any of the above composite retardation films is laminated on the side of the cycloolefin resin film via the third adhesive layer.

The 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 composite phase difference plate, that is, on the side of the first phase difference plate having the (meth)acrylic resin layer. Therefore, the liquid crystal display panel includes a liquid crystal cell and the composite polarizing plate, and the composite polarizing plate is bonded to the liquid crystal cell with the composite phase difference plate side.

According to the present invention, a conventional composite phase in which a first phase difference plate containing a (meth)acrylic resin layer and a second phase difference plate composed of a cycloolefin resin film are adhered via an adhesive is used. The difference in thickness can reduce the thickness, so that a composite phase difference plate or even a liquid crystal panel can be made thinner and lighter. Further, the adhesion between the cycloolefin resin film and the (meth)acrylic resin layer was also good.

10‧‧‧First phase difference plate

12‧‧‧ phase difference display layer

14, 15‧‧‧ (meth)acrylic resin layer

18‧‧‧Second phase difference plate

20‧‧‧Composite phase difference plate

31‧‧‧ adhesive layer

32‧‧‧second adhesive layer

33‧‧‧ third adhesive layer

42‧‧‧ polarizing film

44‧‧‧Protective film

46‧‧‧Adhesive layer

48‧‧‧Separator

50‧‧‧Composite polarizer

Fig. 1 is a schematic cross-sectional view showing an example of a preferred layer configuration of the composite phase difference plate of the present invention.

Fig. 2 is a schematic cross-sectional view showing an example of a preferred layer configuration of the composite polarizing plate of the present invention.

[Composite phase difference plate]

The composite retardation film of the present invention is based on the (meth)acrylic resin layer having the first retardation film of the (meth)acrylic resin layer on the outermost surface, and is made of an active energy ray-curable resin composition. A second retardation film composed of a cycloolefin-based resin film is laminated on the adhesive layer formed of the cured product. Here, the first retardation film may be a (meth)acrylic resin layer which is adhered to the outermost surface of the second phase difference plate made of the cycloolefin-based resin film, and may have a phase difference. . Specifically, it may be a separate film of a (meth)acrylic resin, or may be a A multilayer film including a phase difference display layer made of another resin in addition to the acrylic resin layer. In particular, it is preferable that a (meth)acrylic resin layer is formed on one surface or both surfaces of a phase difference display layer composed of a resin different from the (meth)acrylic resin, and a phase difference is exhibited.

The "(meth)acrylic resin" as used herein, as described in the "Prior Art", is a resin having a (meth) acrylate as a main constituent unit. Further, "(meth)acrylic acid" means any of acrylic acid and methacrylic acid, and "(meth)acrylate" means any of acrylate and methacrylate. In the other parts of the specification, "(meth)", "(meth) acrylate", "(meth) acrylate", "(meth) acrylate", etc. Intention.

An example of a preferred layer configuration of the composite phase difference plate of the present invention is shown in a schematic cross-sectional view in Fig. 1 . The composite phase difference plate of the present invention will be described with reference to Fig. 1 . As shown in Fig. 1, the first retardation film 10 containing the (meth)acrylic resin layer is sequentially laminated with the adhesive layer 31 and the second retardation film 18 composed of the cycloolefin resin film. Further, the composite phase difference plate 20 of the present invention is constructed. Further, the adhesive layer 31 is formed of a cured product of an active energy ray-curable resin composition. In the example shown in the figure, the state of the first phase difference plate 10 is such that the (meth)acrylic resin layer 14 is formed on both sides of the phase difference display layer 12 mainly contributing to the phase difference function. 15.

As has been described before, the (meth)acrylic resin itself has a negative refractive index anisotropy, and a negative phase difference plate is imparted by stretching, so that the first phase difference plate can be made of a separate film thereof. 10. Referring to Fig. 1, the phase difference display layer 12 and the other (meth)acrylic resin layer 15 can be omitted, and the first retardation film 10 can be made only of the (meth)acrylic resin layer 14. However, still as described previously In general, since the (meth)acrylic resin itself has a small phase difference in developability, it is preferably used in combination with the phase difference display layer 12. In this case, the first retardation film 10 may be formed in a state in which the (meth)acrylic resin layer 14 is formed on one surface of the phase difference display layer 12, in other words, the cycloolefin resin is omitted from the first drawing. The state of the (meth)acrylic resin layer 15 of the second phase difference plate 18 made of a film. However, as shown in Fig. 1, when the (meth)acrylic resin layers 14 and 15 are formed on both sides of the phase difference display layer 12, the respective (meth)acrylic resin layers 14 and It is also preferable to use the protective layer of the phase difference display layer 12 as well. Hereinafter, the first phase difference plate 10, the second phase difference plate 18, and the adhesive used to form the adhesive layer 31 for bonding the composite phase difference plate 20 will be described in order.

[First phase difference plate]

As shown in Fig. 1, the first phase difference plate 10 constituting the composite phase difference plate 20 preferably includes a phase difference display layer 12 and a single layer laminated thereon (a ring-shaped olefin resin film is bonded thereto). More preferably, the (meth)acrylic resin layer 14 on the side of the second phase difference 18 includes a phase difference display layer 12 and (meth)acrylic resin layers 14 and 15 laminated on both surfaces thereof. When the (meth)acrylic resin layer is provided on one side or both sides of the phase difference display layer 12, the phase difference display layer 12 may be made of, for example, a styrene resin. Since the styrene resin has a bulky phenyl group in the side chain, the refractive index in the direction orthogonal to the extension axis (the direction orthogonal to the extension axis and the thickness direction) becomes large when uniaxially extending, and is displayed. Negative refractive index anisotropy. Moreover, the phase difference is also large. Therefore, a film made of a styrene resin is suitable as the phase difference display layer 12 for imparting a negative phase difference plate. Negative retardation plate means to a maximum refractive index within the plane direction (slow axis direction) of the refractive index n _x, the refractive index in the direction perpendicular to its plane (fast axis direction) of n _y, and with When the refractive index in the thickness direction is n _z , the film has a relationship of n _z ≒n _x > n _y and an N _z coefficient of about 0. Here, the N _z coefficient is defined by the following formula (1).

N _z coefficient = (n _{x -} n _z ) / (n _{x -} n _y ) (1)

The styrene resin may be a homopolymer of styrene or a derivative thereof, or may be a copolymer of styrene or a derivative thereof and another copolymerizable monomer twice or more. The styrene derivative refers to a compound having a substituent bonded to styrene, and examples thereof include o-methyl styrene, m-methyl styrene, p-methyl styrene, 2,4-dimethyl styrene, and o. Alkyl styrene such as ethyl styrene and p-ethyl styrene; introduction of benzene nucleus in styrene such as hydroxystyrene, tert-butoxystyrene, vinyl benzoic acid, o-chlorostyrene and p-chlorostyrene A substituted styrene such as a hydroxyl group, an alkoxy group, a carboxyl group or a halogen. A terpolymer obtained by copolymerizing a styrene or a styrene derivative with a non-cyclic olefin monomer and a cyclic olefin monomer can also be used. Among them, from the viewpoint of heat resistance, the styrene resin is preferably a styrene or styrene derivative, and at least one monomer selected from the group consisting of acrylonitrile, maleic anhydride, methyl methacrylate, and butadiene. In the same manner, the styrene resin (phase difference display layer 12) preferably has a glass transition temperature of 120 ° C or higher from the viewpoint of heat resistance.

The phase difference display layer 12, in particular, the phase difference display layer 12 composed of a styrene resin, preferably has a thickness of 10 to 100 μm. When the thickness is less than 10 μm, it is difficult to exhibit a sufficient phase difference value by stretching. In addition, when the thickness exceeds 100 μm, the impact strength of the phase difference plate tends to be weak, and the external stress tends to cause a large change in phase difference.

The (meth)acrylic resin constituting the (meth)acrylic resin layers 14 and 15 may, for example, be a homopolymer of an alkyl methacrylate or an alkyl acrylate or a methyl acrylate. a copolymer of an alkyl olefinate and an alkyl acrylate. Specifically, the alkyl methacrylate may, for example, be methyl methacrylate, ethyl methacrylate or propyl methacrylate. Further, specifically, the alkyl acrylate may, for example, be methyl acrylate, ethyl acrylate or acrylic acid. Propyl ester and the like. As such a (meth)acrylic resin, a commercially available general-purpose (meth)acrylic resin can be used. A (meth)acrylic resin may also be referred to as an impact-resistant (meth)acrylic resin.

By laminating the (meth)acrylic resin layers 14 and 15 to the phase difference display layer 12, the chemical resistance and mechanical strength of the first phase difference plate 10 can be improved. In order to further improve the mechanical strength, it is also preferable that the (meth)acrylic resin layers 14 and 15 contain rubber particles. The rubber particles are preferably acrylic. Here, the acrylic rubber particles are rubber-elastic obtained by polymerizing an acrylic monomer having an alkyl acrylate such as butyl acrylate or 2-ethylhexyl acrylate as a main component in the presence of a polyfunctional monomer. particle. The acrylic rubber particles may be formed of a single layer of particles having such rubber elasticity, or may be a multilayer structure having at least one rubber elastic layer. The acrylic rubber particles having a multilayer structure may, for example, be a core having rubber rubber as described above and coated with a hard methacrylic acid ester polymer as a core; and polymerized with a hard alkyl methacrylate; The material is used as a core, and is surrounded by the above-mentioned rubber-elastic acrylic polymer; or the periphery of the hard core is coated with a rubber-elastic acrylic polymer, and further a hard methyl group is surrounded. An alkyl acrylate polymer coated person or the like. The rubber particles formed of the elastic layer generally have an average diameter in the range of about 50 to 400 nm.

The content of the rubber particles in the (meth)acrylic resin layers 14 and 15 is usually about 5 to 50 parts by weight per 100 parts by weight of the (meth)acrylic resin layer. (meth)acrylic resin and acrylic rubber particles are mixed Since it is commercially available, it can be used as a commercial item. An example of a commercially available product in which a (meth)acrylic resin layer of acrylic rubber particles is blended is, for example, "HT 55X" or "Technolloy S001" sold by Sumitomo Chemical Co., Ltd. "Technolloy S001" is sold as a film.

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

As described above, the glass transition temperature of the phase difference display layer 12 is preferably 120 ° C or higher. On the other hand, the glass transition temperature of the (meth)acrylic resin layers 14 and 15 is preferably 120 ° C or lower, and particularly preferably 110 ° C or lower. . Further, it is preferable that the glass transition temperatures of the two do not overlap, and the phase difference display layer 12 preferably has a glass transition temperature higher than that of the (meth)acrylic resin layers 14, 15. This is because it becomes easier to produce a phase difference plate by co-extrusion as will be described later.

The thickness of the (meth)acrylic resin layers 14, 15 is preferably from 10 to 100 μm.

The composite phase difference plate 20 can be co-extruded with the resin forming the phase difference display layer 12 and the resin forming the (meth)acrylic resin layers 14 and 15, respectively, and then formed into a phase difference display layer. The layer is produced by imparting an extension process of the in-plane phase difference. Further, a single layer film can be produced by forming a resin of the phase difference developing layer 12 and a resin forming the (meth)acrylic resin layers 14 and 15, and then a layer can be obtained by thermal fusion by a heat buildup layer. After the film is bonded, it is produced by a method of stretching treatment. The extension system is not particularly limited as long as the desired in-plane retardation value can be obtained, and may be, for example, a longitudinal uniaxial extension, a tensile transverse uniaxial extension, a simultaneous biaxial extension, a sequential biaxial extension, or the like.

The composite phase difference plate 20 is preferably formed as a phase difference display layer as described above. The three-layer structure of the (meth)acrylic resin layers 14 and 15 is laminated on both sides of 12. In this case, these (meth)acrylic resin layers can be formed to have approximately the same thickness. By forming a three-layer structure, the mechanical strength and chemical resistance of the phase difference plate can be further improved. The total film thickness at the time of forming the three-layer structure is from 30 to 200 μm, preferably from 30 to 150 μm, more preferably from 30 to 100 μm.

In the first phase difference plate 10, the in-plane phase difference Re is preferably in the range of 20 to 120 nm, and the Nz coefficient defined by the previous formula (1) is preferably in the range of more than -2 and less than -0.5. The value of the in-plane phase difference Re in the in-plane birefringence multiplied by the thickness of the film is the in-plane biaxial refractive index n _x and n _y defined by the previous formula (1). And the thickness d of the film, and is defined by the following formula (2). Further, the phase difference Rth in the thickness direction is a value obtained by multiplying the birefringence in the thickness direction by the thickness of the film, and is a refractive index n _x and n _{y in the in-} plane two-axis direction, a refractive index n _{z in the} thickness direction, and The thickness d of the film is defined by the following formula (3).

In-plane phase difference value Re=(n _x -n _y )×d (2)

The phase difference in the thickness direction is Rth=[(n _x +n _y )/2-n _z ]×d (3)

The in-plane phase difference Re or the thickness direction phase difference Rth or the Nz coefficient can be obtained by various commercially available phase difference meters. The phase difference or the Nz coefficient may be a value in the vicinity of the center of visible light, for example, at any wavelength between 500 and 600 nm. However, in the present specification, the value at the wavelength of 590 nm is not particularly described.

[Second phase difference plate]

The second phase difference plate 18 constituting the composite phase difference plate 20 of the present invention is a layer of the adhesive layer 31 composed of a cured product of an active energy ray-curable resin composition, as shown in Fig. 1 . The (meth)acrylic resin layer 14 formed on the outermost surface of the first phase difference plate 10 is joined. Here, the second phase difference plate is a cyclic olefin It is composed of a resin film. The cycloolefin-based resin is, for example, a thermoplastic resin having a unit of a monomer composed of a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene-based monomer, and is also called a thermoplastic cycloolefin-based resin. The cycloolefin resin may be a ring-opening polymer of the above cycloolefin or a hydrogen additive of a ring-opening copolymer of two or more kinds of cyclic olefins, or may be a cyclic olefin, a chain olefin or a polymerization such as a vinyl group. An addition polymer of an aromatic compound such as a double bond. A polar group can be introduced into the cycloolefin resin.

When it is a copolymer of a cyclic olefin, a chain olefin, and/or an aromatic compound having a vinyl group, the chain olefin may be ethylene or propylene or the like, and the aromatic compound having a vinyl group may be styrene or α. -methylstyrene, nucleoalkyl-substituted styrene, and the like. In such a copolymer, the unit of the monomer composed of the cyclic olefin may be 50 mol% or less, and preferably 15 to 50 mol% at this time. In particular, when a second phase difference plate is formed using a terpolymer composed of a cyclic olefin, a chain olefin, and an aromatic compound having a vinyl group, the content of the unit of the monomer composed of the cyclic olefin is as described above. Generally it can be a small amount. In this case, the content of the unit of the monomer composed of the chain olefin is generally 5 to 80 mol%, and the content of the unit of the monomer composed of the aromatic compound having a vinyl group is generally 5 to 80 mol%. .

As the cycloolefin-based resin, a suitable commercially available product can be used. For example, "TOPAS", which is produced by TOPAS ADVANCED POLYMERS GmbH, Germany, and sold by Polyplastic in Japan, "Arton" sold by JSR (shares), and sold by Japan Zeon (shares) "ZEONOR" and "ZEONEX", "Apel" (all of which are trade names) sold by Mitsui Chemicals Co., Ltd., etc. In order to form a film by forming a film of such a cycloolefin-based resin, a known method such as a solvent casting method or a melt extrusion method can be suitably used.

The cycloolefin-based resin film is subjected to uniaxial stretching or biaxial stretching to impart a phase difference to form a phase difference plate. The stretching ratio at this time is generally 1.1 to 5 times, preferably 1.1 to 3 times. The retardation plate obtained by the stretching is preferably thin, but if it is too thin, the strength is lowered, the workability tends to be deteriorated, and if it is too thick, the transparency is lowered, and the composite phase difference is poor. The tendency of the weight of the plate or composite polarizing plate to become large. From such a viewpoint, the thickness of the second phase difference plate composed of the cycloolefin resin is generally 5 to 150 μm, more preferably 10 to 100 μm, and particularly preferably 15 to 80 μm.

There is also a cycloolefin-based resin film which is commercially available in a state in which a film is formed in advance and a phase difference is further imparted as the case may be. In the above, the film before the phase difference is applied can be used as the raw material film of the second retardation film of the present invention, and the first aspect of the present invention can be used as long as the phase difference is given. The two phase difference plates are used by themselves. In the case of a commercial product of such a cycloolefin-based resin film, "Zeonor film" sold by Japan Zeon Co., Ltd., "Arton film" sold by JSF (share), "ESCENA" and "SCA 40" (all of which are trade names) sold by Sekisui Chemical Industry Co., Ltd., etc.

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

In the present invention, the second retardation film 18 composed of the cycloolefin-based resin film preferably has an in-plane retardation Re in the range of 30 to 150 nm, and further has an Nz coefficient defined by the above formula (1). It should be in the range of more than 1 and less than 2.

The second phase difference plate composed of the cycloolefin resin film is as follows. The adhesive is adhered to the first retardation film containing the (meth)acrylic resin layer. When the two are adhered, in order to improve the adhesion, the surface of the phase difference plate containing the (meth)acrylic resin layer and/or the surface of the cycloolefin-based resin film bonded thereto may be suitably subjected to plasma treatment and electricity. Surface treatment such as halo treatment, ultraviolet irradiation treatment, flame treatment, saponification treatment, and primer treatment. Hereinafter, an adhesive used for sticking a phase difference plate containing a (meth)acrylic resin layer and a cycloolefin-based resin film will be described.

[Adhesive for sticking first phase difference plate and second phase difference plate]

In the present invention, the adhesive energy of the (meth)acrylic resin layer 14 which is the outermost surface of the first retardation film 10 and the second phase difference plate 18 which is composed of the cycloolefin-based resin film can be used as the active energy. A line curable resin composition. The active energy ray-curable resin composition contains a compound which is cured by irradiation with an active energy ray, that is, contains a curable component. In the present invention, a compound having a N-substituted (meth) acrylamide and a compound having a (meth) acryloxy group in the molecule as a curable component is used.

(N-substituted (meth) acrylamide)

The N-substituted (meth) acrylamide is a (meth) acrylamide having a substituent at the N-position. A typical example of the substituent may be an alkyl group which may be further substituted, but may also form a ring together with a nitrogen atom of (meth) acrylamide, which may contain a nitrogen atom and (meth) acrylamide. In addition to the nitrogen atom, an oxygen atom may be added as a ring constituent member. Further, a substituent such as an alkyl group or a pendant oxy group (=O) may be bonded to a carbon atom constituting the ring. N-substituted (meth) acrylamides can generally be produced by the reaction of (meth)acrylic acid or its chloride with a first or second amine.

The N-substituted (meth) acrylamide is particularly preferably those represented by the above formula (I). In the above formula (I) which represents 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, the respective alkyl groups are carbon numbers. 3 or more, it can be a straight chain or a branch. When Q ₃ is an alkyl group having a hydroxyl group, the hydroxyalkyl group corresponds to this. When Q ₂ and Q ₃ together with the nitrogen atom to which the bond is bonded form a 5-membered ring or a 6-membered ring which may have an oxygen atom as a ring constituent member, the 5-membered ring or the 6-membered ring may be in the N- When the form of a group bonded to a carbonyl group (C=O) is disclosed, there are 1-pyrrolidinyl groups (C ₄ H ₈ N-), 2- Zizodone-3-yl (C ₂ H ₄ OC(=O)N-), piperidinyl (C ₅ H ₁₀ N-), morpholinyl (C ₂ H ₄ OC ₂ H ₄ N-), and the like.

A specific example of an N-substituted (meth) acrylamide corresponding to the formula (I) and wherein Q ₂ is a hydrogen atom and Q ₃ is an alkyl group is N-methyl(meth) acrylamide, N-B. Base (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N- Hexyl (meth) acrylamide and the like. Similarly, specific examples of N-substituted (meth) acrylamides in which Q ₂ and Q ₃ are alkyl groups are N,N-dimethyl(meth)acrylamide, N,N-diethyl Base (meth) acrylamide and the like. Similarly, a specific example of N-substituted (meth) acrylamide having Q ₂ as a hydrogen atom and Q ₃ being an alkyl group having a hydroxyl group is N-hydroxymethyl(meth)acrylamide, N-( 2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, and the like. Further, the formula (I) in the Q ₂ and Q ₃ form, together with the nitrogen atom bonded such as the 5-membered ring or 6-membered ring N- Specific examples of substituted (meth) acrylamide, and N- tied with Propylene decyl pyrrolidine, 3-propenyl fluoren-2- An oxazolidinone, 4-propenylmorpholine, N-propenylpiperidine, N-methylpropenylpiperidine, and the like. Among these, N-hydroxyalkyl (meth) acrylamide such as N-hydroxymethyl acrylamide or N-(2-hydroxyethyl) acrylamide is particularly preferable.

Other, such as N-dodecyl (meth) acrylamide, N-alkyl (meth) acrylamide having a long-chain alkyl group, or N-(methoxymethyl) acrylamide, N-(ethoxyl) N-(alkoxyalkyl)(methyl) acrylamide such as acrylamide, N-(propyloxymethyl) acrylamide and N-(butoxymethyl) acrylamide, It can be used as an N-substituted (meth) acrylamide which forms a hardening component of the active energy ray-curable resin composition.

<Compound with (meth)acryloxyloxy group>

The compound having a (meth)acryloxy group in the molecule as another curable component of the active energy ray-curable resin composition may have at least one (meth) acryloxy group in the molecule. In the following, it is sometimes referred to simply as "(meth) acrylate". Specifically, the (meth) acrylate monomer having at least one (meth) acryloxy group in the molecule or the compound having two or more functional groups obtained by reacting at least two molecules in the molecule ( A (meth) acrylate oligomer such as a methyl propylene oxy group is equivalent to this.

The (meth) acrylate monomer is a monofunctional (meth) acrylate monomer having one (meth) propylene fluorenyloxy group in the molecule, and has two (meth) acrylonitrile groups in the molecule. Among the difunctional (meth) acrylate monomers having an oxy group and a trifunctional or higher polyfunctional (meth) acrylate monomer having three or more (meth) acryloxy groups in the molecule, among these, It is preferably a monofunctional (meth) acrylate monomer, and more preferably an alkyl (meth) acrylate represented by the above formula (II). In the above formula (II) which represents an alkyl (meth)acrylate, when R ₂ is an alkyl group, the alkyl group may be a straight chain or a branch if it has a carbon number of 3 or more. Specific examples of the alkyl (meth)acrylate represented by the above formula (II) include methyl (meth)acrylate, ethyl (meth)acrylate, and isopropyl (meth)acrylate. Butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, and the like. Among these, methyl acrylate is particularly preferred.

Further, an alkyl (meth)acrylate having a higher alkyl group number such as 2-ethylhexyl (meth)acrylate, or an aralkyl (meth)acrylate such as benzyl (meth)acrylate, (methyl) Terpene alcohol (meth) acrylate such as isobornyl acrylate, aminoalkyl (meth) acrylate such as N,N-dimethylaminoethyl (meth)acrylate, and (meth)acrylic acid 2-phenoxyethyl ester, ethyl carbitol (meth) acrylate, and phenoxy polyethylene glycol (meth) acrylate are equivalent to (meth) acrylate having an ether bond at the alcohol moiety, and may also be It is used as a monofunctional (meth) acrylate.

Further, a monofunctional (meth) acrylate having a hydroxyl group at an alcohol moiety or a monofunctional (meth) acrylate having a carboxyl group at an alcohol moiety may be used. Specific examples of the monofunctional (meth) acrylate having a hydroxyl group at the alcohol moiety are 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl methacrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, and the like. Specific examples of the monofunctional (meth) acrylate having a carboxyl group at the alcohol moiety are 2-carboxyethyl (meth)acrylate and 1-[2-(methyl)acryloxyethyl. ] decanoic acid, 1-[2-(methyl) propylene methoxyethyl] hexahydrophthalic acid, 1-[2-(methyl) propylene methoxyethyl] succinic acid, 4-[2-( Methyl) propylene methoxyethyl] trimellitic acid or the like.

The above is an example of a compound having one (meth) acryloxy group in the molecule, but a polyfunctional compound having a plurality of (meth) acryloxy groups in the molecule may be used as a curable component ( Methyl) acrylate. The polyfunctional (meth) acrylate is a bifunctional (meth) acrylate monomer having two (meth) acryloxy groups in the molecule, as described above, and has three or more molecules in the molecule. A trifunctional or higher polyfunctional (meth) acrylate monomer having a (meth) acryloxy group and at least two (meth) propylene in a molecule obtained by reacting two or more compounds having a functional group A methoxyl (meth) acrylate oligomer or the like. Hereinafter, such monomers or oligomers will be specifically described.

Representative examples of the bifunctional (meth) acrylate monomer include, for example, alkylene glycol di(meth)acrylates, polyoxyalkylene glycol di(meth)acrylates, and halogen-substituted alkane. Di(meth)acrylates of alcohols, di(meth)acrylates of aliphatic polyols, di(meth)acrylates of hydrogenated dicyclopentadiene or tricyclodecanedialkyl alcohol, two Alkanol or two a di(meth)acrylate of an alkyldialkanol, a di(meth)acrylate of an alkylene oxide adduct of bisphenol A or bisphenol F, an epoxy group of bisphenol A or bisphenol F (Meth) acrylates and the like.

More specific examples of the bifunctional (meth) acrylate monomer include ethylene glycol di(meth) acrylate, 1,3-butylene glycol di(meth) acrylate, 1, 4 - Butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(methyl) Acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, bis(trimethylolpropane)di(meth)acrylate, diethylene glycol di(methyl) Acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol Di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, di(meth)acrylate of hydroxytrimethylacetate neopentyl glycol ester, 2,2-bis[4- 2-(2-(Methyl)propenyloxyethoxy)ethoxy}phenyl]propane, 2,2-bis[4-2-(2-(methyl)propenyloxyethoxy) Ethoxy}cyclohexyl]propane, hydrogenated dicyclopentadienyl di(meth)acrylate, tricyclodecane dimethanol di(a) ) Acrylate, 1,3-bis Alkane-2,5-diyldi(meth)acrylate [alias: two Alkenyol di(meth)acrylate], hydroxytrimethylacetaldehyde and trimethylolpropane acetal [Chemical name: 2-(2-hydroxy-1,1-dimethylethyl) -5-ethyl-5-hydroxymethyl-1,3-di Di(meth)acrylate of alkane], bis(meth)acrylate of 1,3,5-quino(2-hydroxyethyl) isocyanate, and the like.

A representative example of a trifunctional or higher polyfunctional (meth) acrylate monomer is a poly(meth) acrylate of a trivalent or higher aliphatic polyol. Specific examples thereof include glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, hydrazine (trimethylolpropane) tri(meth)acrylate, and hydrazine ( Trimethylolpropane)tetrakis(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylic acid Ester, dipentaerythritol hexa(meth) acrylate, and the like.

Other, poly(meth) acrylate of a trivalent or higher halogen-substituted polyol, tris(meth) acrylate of an alkylene oxide adduct of glycerin, and an alkylene oxide adduct of trimethylolpropane (Meth) acrylate, 1,1,1-para [2-2-(methyl) propylene oxyethoxy} ethoxy] propane, isocyanuric acid 1,3,5-para [ 2-(Methyl) propylene methoxyethyl] ester or the like may also be a polyfunctional (meth) acrylate monomer.

On the other hand, the (meth) acrylate oligomer is a urethane (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, or an epoxy (meth) acrylate. Ester oligomers and the like.

The urethane (meth) acrylate oligomer refers to a compound having at least two (meth) acryloxy groups in the molecule and having a urethane bond (-NHCOO-) at the same time. Specifically, it may be a urethane-forming reaction product of a hydroxyl group-containing (meth) acrylate monomer having at least one (hydroxy) decyloxy group in the molecule and a polyisocyanate; Or a urethane compound containing a terminal isocyanate group obtained by reacting a polyhydric alcohol with a polyisocyanate, and a hydroxyl group having one hydroxyl group and at least one (meth) acryloxy group in the molecule; A ureidolation reaction product of a (meth) acrylate monomer or the like.

a hydroxyl group-containing (meth) acrylate used in the above urethanation reaction Specific examples of the monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 2-hydroxy(meth)acrylate. 3-phenoxypropyl ester, glycerol di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and the like.

The polyisocyanate supplied to the ureido grouping reaction of the hydroxyl group-containing (meth) acrylate monomer may specifically be, for example, hexamethylene diisocyanate, lysine diisocyanate or isophor. Ketone diisocyanate, dicyclohexylmethane diisocyanate, tolyl diisocyanate, xylylene diisocyanate; a compound obtained by hydrogenating an aromatic diisocyanate, such as hydrogenated tolyl diisocyanate or hydrogenated xylylene diisocyanate Triphenylmethane triisocyanate, diphenylmethylbenzene triisocyanate, polyisocyanate obtained by multiquantifying the diisocyanate in these, and the like.

Further, in order to produce a polyol containing a terminal isocyanato group-containing urethane compound by reacting with a polyisocyanate, an aliphatic or alicyclic polyol may be used, and a polyester polyol may be used. Alcohol, polyether polyol, and the like. Specifically, the aliphatic or alicyclic polyol may, for example, be 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol or neopentyl Alcohol, trimethylolethane, trimethylolpropane, hydrazine (trimethylolpropane), pentaerythritol, dipentaerythritol, dimethylol heptane, dimethylolpropionic acid, dimethylol butyric acid, glycerol , hydrogenated bisphenol A and the like.

The polyester polyol is a compound obtained by subjecting the above polyol to a polyvalent carboxylic acid or an anhydride thereof by a dehydration condensation reaction. Specific examples of the polyvalent carboxylic acid and the acid anhydride thereof are described as "(anhydride)", and succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride) are described. ), trimellitic acid (anhydride), pyromellitic acid (anhydride), hydrazine Acid (anhydride), isophthalic acid, p-nonanoic acid, hexahydrofurfuric acid (anhydride), and the like.

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

The polyester (meth) acrylate oligomer refers to a compound having at least two (meth) acryloxy groups in the molecule and having an ester bond at the same time. Specifically, it can be obtained by a dehydration condensation reaction of (meth)acrylic acid, a polyvalent carboxylic acid or an anhydride thereof, and a polyhydric alcohol. Specific examples of the polyvalent carboxylic acid or its anhydride used in the dehydration condensation reaction include succinic acid (anhydride), adipic acid, and maleic acid (anhydride) when it is described as "(anhydride)". , itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), hexahydrophthalic acid (anhydride), citric acid (anhydride), isophthalic acid, citric acid, and the like. Further, specific examples of the polyhydric alcohol used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol. , neopentyl glycol, trimethylolethane, trimethylolpropane, hydrazine (trimethylolpropane), pentaerythritol, dipentaerythritol, dimethylol heptane, dimethylolpropionic acid, dihydroxyl Butyric acid, glycerin, hydrogenated bisphenol A, and the like.

Epoxy (meth) acrylate oligomer refers to an addition reaction of polyglycidyl ether and (meth)acrylic acid, or at least 2 (meth) propylene oxime in the molecule base. Specific examples of the polyglycidyl ether used in the addition reaction include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and 1,6-hex. Glycol diglycidyl ether, bisphenol A diglycidyl ether, and the like.

<The ratio of the amount of N-substituted (meth) acrylamide to (meth) acrylate>

In the present invention, the N-substituted (meth) acrylamide and (meth) acrylate described above are used in combination as a curable component in the active energy ray-curable resin composition. The relationship between the amounts includes both, and the compound is also contained when it contains other compounds which are hardened by irradiation with an active energy ray. The N-substituted (meth) acrylamide is 60 based on the total amount of the curable component. It is 80% by weight, more preferably 70 to 80% by weight, and the (meth) acrylate is 20 to 40% by weight, more preferably 20 to 30% by weight. When the N-substituted (meth) acrylamide represented by the above formula (I) and the alkyl (meth) acrylate represented by the above formula (II) are used, the amount of the curable component is also used in the same manner. The ratio of the N-substituted (meth) acrylamide represented by the formula (I) is from 60 to 80% by weight, more preferably from 70 to 80% by weight, and the (meth)acrylic acid represented by the formula (II) The ratio of the alkyl ester is from 20 to 40% by weight, more preferably from 20 to 30% by weight. The ratio of the N-substituted (meth) acrylamide as a representative example of the compound represented by the formula (I) is less than 60% by weight in the entire curable component, in other words, the compound represented by the formula (II) is used. When the ratio of the (meth) acrylate of the representative example is more than 40% by weight in the entire curable component, the adhesion to the cycloolefin resin film tends to decrease. In addition, the ratio of the N-substituted (meth) acrylamide as a representative example of the compound 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 (II) When the ratio of the (meth) acrylate is less than 20% by weight in the entire curable component, the adhesion of the phase difference plate containing the (meth)acrylic resin layer tends to decrease.

<Photoradical polymerization initiator>

The active energy ray-curable resin composition contains the N-substituted (meth) acrylamide and the (meth) acrylate described above as a curable component, and therefore all of them are radical polymerizable compounds. It is preferred to formulate a photoradical polymerization initiator. The photoradical polymerization initiator may be any one that can be used to initiate polymerization of a radically polymerizable compound by irradiation with an active energy ray, and a conventionally known one can be used. To lift Specific examples of the photo-radical polymerization initiator are: acetophenone, 3-methylethyl benzene, benzyl dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxyl -2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl-2-morpholinylpropan-1-one and 2-hydroxy-2-methyl-1 Anthraquinone-based initiator such as phenylpropan-1-one; benzophenone starting from benzophenone, 4-chlorobenzophenone and 4,4'-diaminobenzophenone a benzoin ether initiator such as benzoin propyl ether or benzoin ethyl ether; a thioxanthone initiator such as 4-isopropylthionone; other such as oxygen Xanthone, anthrone, camphorquinone, benzaldehyde, anthraquinone, and the like.

The amount of the photoradical polymerization initiator is usually 0.5 to 20 parts by weight based on 100 parts by weight of the radically polymerizable compound containing N-substituted (meth)acrylamide and (meth) acrylate. It is preferably from 1 to 6 parts by weight. When the amount of the photoradical polymerization initiator is small, the hardening becomes insufficient, and the mechanical strength or the adhesion tends to be lowered. In addition, when the amount of the photoradical polymerization initiator is too large, the amount of the active energy ray-curable compound in the curable resin composition is relatively small, and the durability of the obtained composite phase difference plate may be lowered. .

<Other optional components that can be formulated in the curable resin composition>

The active energy ray-curable resin composition may further contain a photosensitizer as needed. The reactivity of the radical polymerization can be improved by blending the photosensitizer, and the mechanical strength or adhesion of the adhesive layer can be improved. The photosensitizer may be a compound having a maximum absorption at a wavelength longer than 380 nm, and examples thereof include a carbonyl compound, an organic sulfur compound, a persulfide compound, a redox compound, an azo (azo) compound, and a diazo compound. A halogen compound, a quinone compound, a photoreductive dye, or the like. Examples of the carbonyl compound which can be used as a photosensitizer include benzoin methyl ether, benzoin isopropyl ether, and benzene such as 2,2-dimethoxy-2-phenylethyl benzene. Occasion derivative; diphenyl Ketone, 2,4-dichlorobenzophenone, methyl o-benzhydryl benzoate, 4,4'-bis(dimethylamino)benzophenone and 4,4'-double (two a benzophenone compound such as ethylamino)benzophenone; a thioxanthone derivative such as 2-chlorothiazinone or 2-isopropylthioxanthone; 2-chloroindanone and 2- An anthrone derivative such as methyl fluorenone; an acridone derivative such as N-methylacridone or N-butylacridone. The lanthanoid compound is preferably an alkoxy group at the 9th and 10th positions of the oxime. If an oxime compound which can be a photosensitizer is exemplified, there are 9,10-dipropoxy fluorene and 2-methyl group. -9,10-dipropoxy fluorene, 2-ethyl-9,10-dipropoxy fluorene, 9,10-dibutoxy fluorene, 2-methyl-9,10-dibutoxy fluorene , 2-ethyl-9,10-dibutoxyfluorene, and the like. These photosensitizers may be used alone or in combination of two or more. When the photosensitizer is formulated in an amount of 100 parts by weight based on the total amount of the active energy ray-curable compound, it is usually about 0.1 to 20 parts by weight.

Further, the active energy ray-curable resin composition may also contain an antistatic agent for imparting antistatic properties. As the antistatic agent, various known ones can be used. For example, a cationic surfactant, an anionic surfactant, a nonionic surfactant, an ionic compound having an organic cation other than the above cationic surfactant, an ionic compound having an organic anion other than the above anionic surfactant, and a conductive material can be used. Inorganic particles, conductive polymers, and the like. The blending ratio of the antistatic agents is appropriately determined in accordance with the desired properties. When the total amount of the active energy ray-curable compound is 100 parts by weight, it is usually about 0.1 to 10 parts by weight.

The active energy ray-curable resin composition may also contain a known polymer additive which is generally used in polymers. For example, a primary antioxidant such as a phenol type or an amine type, a sulfur-based secondary antioxidant, a hindered amine light stabilizer (HALS), a benzophenone type, a benzotriazole type, a benzoate type, etc. UV absorbers, etc.

A leveling agent can also be formulated in the active energy ray-curable resin composition. When this When the curable resin composition is applied to a first retardation film having a (meth)acrylic resin layer on the outermost surface or a second retardation film comprising a cycloolefin-based resin film, if coating property is lacking, The wettability can be improved by blending a leveling agent. 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, or a titanate type 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.

Further, the active energy ray-curable resin composition may contain a solvent as needed. The solvent is appropriately selected in consideration of the solubility of the component constituting the curable resin composition. The solvent to be used generally includes, for example, aliphatic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; and 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; methyl cellosolve, ethyl cellosolve and a cellosolve such as butyl cellosolve; a halogenated hydrocarbon such as dichloromethane or chloroform. The blending ratio of the solvent is appropriately determined from the viewpoints of the viscosity adjustment according to the purpose of processing such as film forming property or the optimum viscosity range in the coating method to be used.

The active energy ray-curable resin composition forming the adhesive layer 31 is applied to any of the adhesion surfaces of the first retardation film 10 and the second retardation film 18, and another phase difference plate is laminated thereon. . The application of the active energy ray-curable resin composition can be carried out by various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater.

The light source used for the irradiation of the active energy ray is not particularly limited, and can be used for, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, a black light lamp, or the like having a light-emitting distribution at a wavelength of 400 nm or less. Microwave-excited mercury lamps, metal halide lamps, and the like. The light irradiation intensity of the active energy ray-curable resin composition varies depending on each composition, but it is preferably an irradiation intensity of 10 to 2500 mW/cm ² in a wavelength region effective for activation of the polymerization initiator. When the light irradiation intensity of the active energy ray-curable resin composition is too small, the time required until the reaction proceeds sufficiently, and conversely, if the intensity is too large, heat and active energy may be radiated from the lamp. When the linear curable resin composition is heated during polymerization, yellowing of the active energy ray-curable resin composition or deterioration of the adhered film is caused. The light irradiation time of the active energy ray-curable resin composition is not particularly limited, and is preferably set so that the integrated light amount indicated by the product of the irradiation intensity and the irradiation time is 10 to 2,500 mJ/cm ² . When the integrated light amount of the active energy ray-curable resin composition is too small, the generation of the active species derived from the polymerization initiator is insufficient, and the curing of the obtained adhesive layer may be insufficient. Further, if the amount of integrated light is too large, the irradiation time becomes very long, which is disadvantageous for improving productivity.

[Composite polarizer]

The composite phase difference plate 20 of the present invention which is an example of a layer configuration in Fig. 1 can be combined with a polarizing plate to form a composite polarizing plate. An example of a preferred layer configuration of the composite polarizing plate of the present invention is shown in a schematic cross-sectional view in Fig. 2 . As shown in the figure, a protective film 44 made of a thermoplastic resin is laminated on one surface of the polarizing film 42 via a second adhesive layer 32, and a third adhesive layer 33 is disposed on the other surface of the polarizing film 42. The composite phase difference plate 20 described above is laminated on the side of the second phase difference plate 18 made of a cycloolefin resin to form the composite polarizing plate 50, with reference to Fig. 1 . On the surface of the composite phase difference plate 20 opposite to the surface to be bonded to the polarizing film 42, an adhesive layer 46 for bonding to other members such as liquid crystal cells is generally provided, and temporary protective adhesion is provided on the outer side thereof. a separator 48 on the surface of the agent layer 46 to fit To other components. Further, in Fig. 2, in order to make the relationship between the layers easier to understand, a part of the layers are separated and displayed, but in reality, the adjacent layers are in contact with each other and adhered to each other. Hereinafter, each member constituting the composite polarizing plate 50 will be described in detail. However, the composite phase difference plate and the components constituting the composite phase difference plate are the same as those described above with reference to FIG. 1, and the description thereof will be omitted.

[Polarizing film]

Specifically, the polarizing film 42 is a method in which a polyvinyl alcohol-based resin film is adsorbed and aligned with a dichroic dye. By performing uniaxial stretching at any stage before, during or after adsorption of the dichroic dye, the dichroic dye in the polyvinyl alcohol resin film can be aligned in the extending direction. The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. The polyvinyl acetate-based resin may, for example, be a polyvinyl acetate which is a homopolymer of vinyl acetate, and may, for example, be a copolymer of vinyl acetate and another monomer copolymerizable therewith, for example. Ethylene-vinyl acetate copolymer and the like. The single system which can be copolymerized with vinyl acetate may, for example, be an unsaturated carboxylic acid, an unsaturated sulfonic acid, an olefin such as the above ethylene, a vinyl ether or an acrylamide having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin is generally from 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, an aldehyde-modified polyvinyl formal, a polyvinyl acetal, or a polyvinyl butyral (polyvinyl) may be used. Butyral) and so on. Further, the degree of polymerization of the polyvinyl alcohol-based resin is usually in the range of from 1,000 to 10,000, preferably in the range of from 1,500 to 5,000.

When such a polyvinyl alcohol-based resin is formed into a film, it can be used as a raw material film of a polarizing film. The method of forming a film of a polyvinyl alcohol-based resin is not particularly limited. The film can be formed according to a conventionally known appropriate method. The film thickness of the raw material film made of a polyvinyl alcohol-based resin is not particularly limited, but is, for example, about 10 to 150 μm.

In general, the polarizing film is a polyvinyl alcohol-based resin film which is obtained by dyeing a polyvinyl alcohol-based resin film with a dichroic dye to adsorb the dichroic dye (dyeing step) and adsorbing a dichroic dye. The step of treating with a boric acid aqueous solution (boric acid treatment step) and the step of washing with the aqueous boric acid solution followed by water washing (water washing treatment step) are carried out.

Further, although uniaxial stretching is also performed, the uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before the dyeing treatment step, or may be carried out in the dyeing treatment step, or may be performed after the dyeing treatment step. When the uniaxial stretching is performed after the dyeing treatment step, the uniaxial stretching may be performed before the boric acid treatment step or in the boric acid treatment step. Of course, uniaxial stretching can also be performed in these multiple stages. The uniaxial stretching can be carried out by passing the film through a separation roll having a peripheral speed, or by sandwiching the film with a heat roll. Further, it may be a dry stretching which is extended in the atmosphere, or may be a wet stretching which is extended in a state of being swollen with a solvent. The stretching ratio is generally 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, specifically, iodine or a dichroic organic dye can be used. The dichroic organic dye comprises: a dichroic direct dye composed of a disazo compound such as CIDIRECT RED 39, and a compound composed of a trisazo or a tetrakisazo compound. Dichromatic direct dye. Further, the polyvinyl alcohol-based resin film is preferably subjected to a water immersion treatment before the dyeing treatment.

When iodine is used as a dichroic dye, it is generally used in water containing iodine and potassium iodide. A method of dyeing a solution by immersing a polyvinyl alcohol-based resin film in a solution. The content of iodine in the 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 to be dyed is generally 20 to 40 ° C, and the immersion time (dyeing time) of the aqueous solution is generally 20 to 1800 seconds.

Further, when a dichroic organic dye is used as the dichroic dye, a method in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing an aqueous solution of a dichroic organic dye and dyed is generally used. The content of the dichroic organic dye in the aqueous solution is usually from 1 × 10 ^-4 to 10 parts by weight, preferably from 1 × 10 ^-3 to 1 part by weight, more preferably 1 part by weight per 100 parts by weight of water. ×10 ^-3 to 1 × 10 ^-2 parts by weight. The aqueous solution may also contain an inorganic salt such as sodium sulfate as a dyeing aid. When a dichroic organic dye is used as the dichroic dye, the temperature of the aqueous solution to be dyed is generally 20 to 80 ° C, and the immersion time (dyeing time) of the aqueous solution is usually 10 to 1800 seconds.

The boric acid treatment step can be carried out by immersing the polyvinyl alcohol-based resin film dyed with the dichroic dye in an aqueous boric acid solution. The content of boric acid in the aqueous boric acid solution is usually 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of the water. When iodine is used as the dichroic dye in the above dyeing treatment step, the aqueous boric acid solution used in this step preferably contains potassium iodide. At this time, 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 the water. The immersion time for the aqueous boric acid solution is generally from 60 to 1200 seconds, preferably from 150 to 600 seconds, more preferably from 200 to 400 seconds. The temperature of the aqueous boric acid solution is usually 50 ° C or higher, preferably 50 to 85 ° C, more preferably 60 to 80 ° C.

Then, in the water washing treatment step, the polyethylene treated by the above boric acid is used The alcohol resin film is immersed in water, for example, and is subjected to a water washing treatment. The temperature of the water in the water washing treatment is generally 5 to 40 ° C, and the immersion time is usually 1 to 120 seconds. After the water washing treatment, a drying treatment is generally performed to obtain a polarizing film. The drying treatment can be carried out, for example, using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually from 30 to 100 ° C, preferably from 50 to 80 ° C. The drying treatment time is generally from 60 to 600 seconds, preferably from 120 to 600 seconds.

According to the above, a polarizing film in which a uniaxially stretched polyvinyl alcohol-based resin film is adsorbed and has a dichroic dye can be produced. The polarizing film may have a thickness of about 5 to 40 μm.

[Protective film made of thermoplastic resin]

As described above, the second retardation film 18 made of the cycloolefin-based resin film constituting the composite phase difference plate 20 can be bonded to one surface of the polarizing film 42 and bonded to the surface on the opposite side of the polarizing film 42 by thermoplasticity. Another protective film 44 composed of a resin. The protective film 44 is also bonded to the polarizing film 42 via an adhesive. The protective film 44 can be widely used as a protective film in the field, for example, a cellulose acetate resin, a polyolefin resin, an acrylic resin, a polyimide resin, a polycarbonate resin, a polyester resin, or the like. It consists of a suitable material used to form the material. From the viewpoint of mass productivity or adhesion, among these, a cellulose acetate resin film is preferably used as the protective film 44. From the viewpoint of easiness in providing the surface treatment layer and optical characteristics, a cellulose acetate resin film is preferably used as the protective film 44.

The cellulose acetate-based resin film is a film composed of a part of cellulose or a completely acetate ester, and examples thereof include a triethylenesulfonated cellulose film and a diethyl fluorene-based cellulose film. As such a cellulose acetate-based resin film, a commercially available product such as "Fujitac TD80" or "Fujitac TD80UF" sold by Fuji Film Co., Ltd., and "Fujitac TD80UZ", "KC8UX2M", "KC8UY", and "KC4UEW" sold by Konica Minolta Opto (shares, all of which are trade names).

The polarizing film 42 and the protective film 44 made of a thermoplastic resin are bonded together using an appropriate adhesive described later. In order to improve the adhesion between the two, plasma treatment, corona treatment, ultraviolet irradiation treatment, flame treatment, saponification treatment, primer treatment, etc. may be appropriately applied to either or both of the two surfaces. Subsequent surface treatment. When the protective film 44 is formed of a cellulose acetate-based resin film and adhered to the polarizing film 42 by using a water-based adhesive to be described later, one of preferable surface treatments to the cellulose acetate-based resin film is, for example, a saponification treatment. The saponification treatment is carried out by immersing a film in an aqueous solution of an alkali such as sodium hydroxide or potassium hydroxide.

The protective film 44 made of a thermoplastic resin is preferably thin. However, if it is too thin, the strength is lowered and the workability tends to be deteriorated. On the other hand, if it is too thick, the transparency is lowered, or The weight of the composite polarizing plate 50 tends to increase. From such a viewpoint, the thickness of the protective film 44 is generally 10 to 200 μm, preferably 20 to 150 μm, more preferably 30 to 100 μm.

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

[Adhesive for bonding polarizing film to protective film and composite phase difference plate]

The adhesion of the polarizing film 42 to the protective film 44 made of a thermoplastic resin and the adhesion of the polarizing film 42 to the second phase difference plate 18 constituting the composite phase difference plate 20 are as follows. Thereby, as shown in FIG. 2, the second adhesive layer 32 is formed between the polarizing film 42 and the protective film 44, and the third adhesive layer 33 is formed between the polarizing film and the second phase difference plate 18. Therefore, the adhesive used is as long as it is displayed for both. The active ingredient may be, for example, a water-based adhesive in which an adhesive component is dissolved or dispersed in water, or a curable adhesive containing an active energy ray-curable compound. When the surface of the polarizing film 42 is considered to be hydrophilic, it is preferably a water-based adhesive which dissolves or disperses the adhesive component in water. From the viewpoint of making the adhesive layer after hardening thin, a water-based adhesive is also preferred. A polyvinyl alcohol-based resin, a urethane resin, or the like can be used as the main component of the aqueous binder. Further, the adhesive agent constituting the second adhesive layer 32 and the third adhesive layer 33 may be the same or different, but if an appropriate adhesiveness is obtained, the same use is used from the viewpoint of work efficiency. It is beneficial.

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

The degree of saponification of the polyvinyl alcohol-based resin used in the subsequent agent is generally 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 is low, the water resistance of the obtained adhesive layer tends to be insufficient.

The modified polyvinyl alcohol-based resin is preferably used in the subsequent step. The suitable modified polyvinyl alcohol-based resin may, for example, be a polyvinyl alcohol-based resin modified with an acetamidine group, an anion-modified polyvinyl alcohol-based resin, or a cationically modified polyvinyl alcohol. Resin or the like. If such a modified polyvinyl alcohol-based resin is used, it is easy to obtain Improve the water resistance of the adhesive layer.

The polyvinyl alcohol-based resin modified with an acetamidine group has an ethyl acetonitrile group (CH ₃ COCH ₂ CO-) in addition to the hydroxyl group constituting the polyvinyl alcohol-based resin skeleton, and may have other A sulfhydryl group, such as an ethyl group. Typically, the acetamidine group is present in a state in which a hydrogen atom constituting a hydroxyl group of the polyvinyl alcohol is substituted. The polyvinyl alcohol-based resin modified with an acetamidine group can be produced, for example, by a method in which polyvinyl alcohol is reacted with diketene. The polyvinyl alcohol-based resin modified with an acetamidine group is preferred because it has a highly reactive ethylenic acid group. Therefore, it is preferable to improve the durability of the adhesive layer.

The content of the ethyl oxime group in the polyvinyl alcohol-based resin modified with the acetamidine group is not particularly limited as long as it is 0.1 mol% or more. The content of the acetamidine group in the above is a percentage of the total amount of the hydroxyl group of the polyvinyl alcohol-based resin, the ethyl hydrazide group, and the other thiol group (ethyl fluorenyl group). The value of the molar fraction is sometimes referred to as "the degree of acetylation". When the degree of acetylation of 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 acetylation of the polyvinyl alcohol-based resin is preferably from about 0.1 to 40 mol%, more preferably from 1 to 20 mol%, particularly preferably from 2 to 7 mol%. When the degree of acetylation of the ethyl oxime exceeds 40 mol%, the effect of improving the water resistance tends to be small.

The anion-modified polyvinyl alcohol-based resin has an anionic group (typically a carboxyl group (-COOH) or a salt thereof) in addition to a hydroxyl group constituting the polyvinyl alcohol skeleton, and may have other mercapto groups, for example, Ethyl group and so on. 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 and then saponifying. Further, the cationically modified polyvinyl alcohol-based resin has a cationic group (typically a tertiary amino group or a quaternary ammonium group) in addition to a hydroxyl group constituting the polyvinyl alcohol skeleton, and may have other defects. Base, such as ethyl thiol and the like. The cationically modified polyvinyl alcohol-based resin may be, for example, obtained by copolymerizing an unsaturated monomer having a cationic group (typically a tertiary amino group or a quaternary ammonium group) with vinyl acetate. The method of saponification is manufactured.

The adhesive used in the present invention may be one or more types of the above-mentioned modified polyvinyl alcohol-based resin, or may be an unmodified polyvinyl alcohol-based resin such as a wholly or partial saponified product of polyvinyl acetate. And a substance of both of the modified polyvinyl alcohol-based resins.

The adhesive agent containing a polyvinyl alcohol-based resin as a main component may be used in the form of an aqueous solution. Therefore, the concentration thereof is preferably in the range of 1 to 20 parts by weight based on 100 parts by weight of water. It is from 1 to 15 parts by weight, more preferably from 1 to 10 parts by weight, particularly preferably from 2 to 10 parts by weight. When the concentration of the polyvinyl alcohol-based resin in the aqueous solution is too small, the adhesion tends to be lowered, and if the concentration is too large, the optical characteristics of the obtained polarizing plate tend to be lowered. The water used in the adhesive may be pure water, ultrapure water, tap water, etc., and has no characteristic limitation, but from the viewpoint of maintaining the uniformity and transparency of the formed adhesive layer, it is preferably pure water or ultrapure. water. Further, an alcohol such as methanol or ethanol may be added to the aqueous solution of the adhesive.

The polyvinyl alcohol-based resin constituting the adhesive can be appropriately selected from commercially available products and used. Specifically, for example, "PVA-117H" which is a polyvinyl alcohol having a high degree of saponification and sold by Kuraray, or "Gohsenol NH-20" which is sold from the Japanese synthetic chemical industry. "The "Gohsefimer Z" series, which is a polyvinyl alcohol modified by an acetamidine group and sold by the Japan Synthetic Chemical Industry Co., Ltd., belongs to the anion. Modified polyvinyl alcohol and "KL-318" and "KM-118" sold by Kuraray, or "Gohsenol T-330" sold by Japan Synthetic Chemical Industry Co., Ltd., which are modified by cations "CM-318" which is sold by Kuraray, "Gohsefimer K-210" sold by Japan Synthetic Chemical Industry Co., Ltd. (all of which are trade names).

The water-based adhesive containing a polyvinyl alcohol-based resin as a main component may contain a crosslinking agent. The crosslinking agent is not particularly limited as long as it contains a functional group reactive with a polyvinyl alcohol-based resin, and can be used conventionally in a polyvinyl alcohol-based resin. If a compound which can be a crosslinking agent is disclosed depending on the difference in functional groups, there are: an isocyanate compound having at least 2 isocyanato groups (-NCO) in the molecule; and having at least 2 epoxy groups in the molecule (epoxy) Group) of epoxy compounds; mono- or di-aldehydes; organotitanium compounds; inorganic salts of divalent or trivalent metals such as magnesium, calcium, iron, nickel, zinc, and aluminum; metal salts of glyoxylic acid; Hydroxymethyl melamine and the like.

Specific examples of the isocyanate compound to be a crosslinking agent include, for example, tolyl diisocyanate, hydrogenated tolyl diisocyanate, an adduct of trimethylolpropane and tolyl diisocyanate, diphenylmethane diisocyanate, and the like. Phenylmethane triisocyanate, isophorone diisocyanate, ketoxime blocks or phenolic blocks, and the like.

Specific examples of the epoxy group-forming compound to be a crosslinking agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol di- or tri-glycidyl ether, and 1,6. - hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diglycidylamine; polymerization of a reactant belonging to a polyalkylene polyamine and a dicarboxylic acid A polyamide polyamine, a water-soluble polyamine epoxy resin obtained by reacting with epichlorohydrin or the like.

Specific examples of the monoaldehyde to be a crosslinking agent include, for example, formaldehyde, acetaldehyde, and propionaldehyde. Specific examples of the dialdehydes such as butyraldehyde include, for example, glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, maleic aldehyde, and phthalaldehyde.

An organic titanium compound which becomes a crosslinking agent is sold by Matsumoto Fine Chemical Co., Ltd. in various commodities. From the company's organic titanium compound related webpage (retrieved by the Internet <URL: http://www.m-chem.co.jp/products/productsl.html> in Heisei 23 (2011) November 16 The water-soluble organotitanium compound to which the present invention is applied is disclosed in the order of its formula, the company's chemical name, and the company's trade name, as follows: [(CH ₃ ) ₂ CHO] ₂ Ti[OCH ₂ CH ₂ N(CH ₂ CH ₂ OH) ₂ ] ₂ : The company's chemical name is "titanium diisopropoxy bis (triethanolamine)", the trade name of the company "Orgatix TC-400"; [(HO) ₂ Ti[OCH(CH ₃ )COO ^- ] ₂ (NH ₄ ⁺ ) ₂ : The company's chemical name is "titanium lactate ammonium salt" at the company The trade name is "Orgatix TC-300"; [(HO) ₂ Ti[OCH(CH ₃ )COOH] ₂ : The company's chemical name is "titanium lactate", the trade name of the company is " Orgatix TC-310" and "Orgatix TC-315".

Further, the metal salt of 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, an epoxy compound such as the above-mentioned water-soluble polyamine epoxy resin, or an aldehyde, methylol melamine, an alkali metal salt of glyoxylic acid or an alkaline earth metal salt can be preferably used.

The crosslinking agent is preferably dissolved in water together with a polyvinyl alcohol-based resin to form an adhesive. However, as described below, the amount of the crosslinking agent in the aqueous solution may be only a little required, so that it can be used as a crosslinking agent as long as it has a solubility of at least 0.1% by weight with respect to water. Of course, the cross-linking agent used in the present invention is generally referred to as water-soluble. Compounds which are soluble in water are preferred.

The amount of the crosslinking agent is appropriately designed according to the type of the polyvinyl alcohol-based resin, etc., but it is usually 5 to 60 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the polyvinyl alcohol-based resin. If the crosslinking agent is blended in this range, good adhesion can be obtained. As described above, in order to improve the durability of the adhesive layer, it is preferred to use a polyvinyl alcohol-based resin modified with an acetamidine group, but at this time, it is preferable to mix and match with respect to 100 parts by weight of the polyvinyl alcohol-based resin. The crosslinking agent is 5 to 60 parts by weight, more preferably 10 to 50 parts by weight. If the amount of the crosslinking agent is too large, the crosslinking reaction of the adhesive agent is carried out in a short time, and the adhesive tends to gel rapidly, so that the pot life is extremely short and difficult to use. Industrial.

In the adhesive, a conventionally known suitable additive such as a decane coupling agent, a plasticizer, an antistatic agent, or fine particles may be blended in a range that does not inhibit the effects of the present invention.

When a urethane resin is used as a main component of the aqueous binder, examples of a suitable binder include, for example, a polyester-based ionic polymer (ionomer) type urethane resin and a compound having a glycidyloxy group. a mixture. Here, the polyester-based ionic polymer type urethane resin refers to a urethane resin having a polyester skeleton, and a small amount of an ionic component (hydrophilic component) is introduced therein. Since such an ionic polymer type urethane resin is directly emulsified in water to form an emulsion without using an emulsifier, it is suitably used as a water-based adhesive. The use of a polyester-based ionic polymer-type urethane resin for a polarizing film and a protective film is described in, for example, Japanese Laid-Open Patent Publication No. 2005-070140, and Japanese Patent No. 4432487 (=Japanese Patent Co., Ltd.) It is known from Japanese Laid-Open Patent Publication No. 2005-208456.

The adhesion of the polarizing film 42 to the protective film 44 and/or the second phase difference plate 18 made of a cycloolefin resin may be a hard one containing an active energy ray-curable compound. Chemical adhesive. The "active energy ray-curable compound" means a compound which can be hardened by irradiation with an active energy ray. The active energy ray-curable compound may be a cationically polymerizable one or a radical polymerizable one. Examples of the cationically 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. Further, examples of the radical polymerizable compound include, for example, a (meth)acrylic compound having at least one (meth)acryloxy group in the molecule.

The active energy ray-curable compound for sticking preferably contains at least an epoxy compound, and particularly exhibits good adhesion between the polarizing film 42 and the second phase difference plate 18 composed of the cycloolefin resin film. Adhesiveness. In addition, when the protective film 44 is formed of a cellulose acetate-based resin film, the active energy ray-curable adhesive having an epoxy compound as a curable component exhibits good adhesion to the polarizing film 42 as well.

From the viewpoints of weather resistance, refractive index, cationic polymerizability, and the like, the epoxy compound is preferably an epoxy compound containing no aromatic ring in the molecule as a main component. The epoxy compound which does not contain an aromatic ring in the molecule may, for example, be a glycidyl ether of a polyhydric alcohol having an alicyclic ring, an aliphatic epoxy compound, or an alicyclic epoxy compound. An epoxy compound which can be suitably used in such an active energy ray-curable adhesive is described in detail, for example, in Japanese Patent No. 4,306,270 (Japanese Patent Application Laid-Open No. Hei No. 2004-245925).

A glycidyl ether of a polyhydric alcohol having an alicyclic ring, which can be obtained by hydrogenating a aromatic polyhydric alcohol selectively in the presence of a catalyst under pressure and an aromatic ring to obtain a nuclear hydrogenated polyhydroxy compound. Further, the nuclear hydrogenated polyhydroxy compound is subjected to glycidyl etherification. Examples of the aromatic polyol include bisphenol A and bisphenol. F, and bisphenol type compounds such as bisphenol S; phenol novolac resin, cresol novolac resin, and phenol novolak resin such as hydroxybenzaldehyde phenol novolak resin; tetrahydroxydiphenylmethane, tetrahydroxyl A polyfunctional compound such as benzophenone or polyvinylphenol. When an alicyclic polyol obtained by hydrogenating an aromatic ring of such an aromatic polyol is reacted with epichlorohydrin, hydrazine can form a glycidyl ether. Among the glycidyl ethers of the polyol having such an alicyclic ring, for example, a diglycidyl ether of hydrogenated bisphenol A is preferable.

The aliphatic epoxy compound may be a polyglycidyl ether of an aliphatic polyol or an alkylene oxide adduct thereof. More specifically, for example, diglycidyl ether of 1,4-butanediol; diglycidyl ether of 1,6-hexanediol; triglycidyl ether of glycerol; trimethylolpropane Triglycidyl ether; diglycidyl ether of polyethylene glycol; diglycidyl ether of propylene glycol; addition of one or more epoxy groups to aliphatic polyols such as ethylene glycol, propylene glycol or glycerin A polyglycidyl ether of a polyether polyol obtained by an alkane (ethylene oxide or propylene oxide).

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 the alicyclic ring" means the oxygen atom -O- of the bridge in the structure represented by the following formula (III), wherein n is an integer of 2 to 5.

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

The above epoxy compound is preferably an alicyclic epoxy compound, that is, preferably a compound having at least one epoxy group bonded to the alicyclic ring, especially having an oxacyclohexane ring [in the above formula The epoxy compound in (III) where n = 3 or the oxaheterocycloheptane ring [n=4 in the above formula (III)] has a high modulus of elasticity due to the cured product, and is in a polarizing film and protection. The film will give good adhesion between the films, so it is more suitable to use. Specific examples of the alicyclic epoxy compound are disclosed below. Here, the compound name is given first, and then the corresponding chemical formula is indicated, and the compound name and the corresponding chemical formula are given the same symbols.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylic acid, 3:4-ring of 3,4-epoxy-6-methylcyclohexanecarboxylic acid Oxy-6-methylcyclohexylmethyl ester, C: exoethyl bis(3,4-epoxycyclohexanecarboxylate), D: adipic acid bis(3,4-epoxycyclohexyl) Methyl)ester, 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-tetraoxa Snail [5.2.2.5.2.2] icosane, 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 Oxide, etc.

A:

B:

C:

D:

E:

F:

G:

H:

I:

J:

K:

L:

M:

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

Further, the active energy ray-curable adhesive may contain an oxetane compound in addition to the epoxy compound. By adding an oxetane compound, the viscosity of the above-mentioned adhesive can be lowered, and the hardening speed can be accelerated.

The oxetane compound is a compound having at least one oxetane ring (4-membered cyclic ether) in the molecule, and examples thereof include 3-ethyl-3-hydroxymethyloxetane and 1, 4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, bis[( 3-ethyl-3-oxetanyl)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, phenol novolac oxirane Alkane, etc. The amount of the oxetane compound is generally 50% by weight or less, preferably 10% to 40% by weight based on the total of the active energy ray-curable resin compound. The oxetane compound can be easily obtained as a commercial product, and for example, all of them are sold under the trade names "Aron oxetane OXT-101", "Aron oxetane OXT-121", "Aron oxetane OXT" sold from East Asia Synthetic Co., Ltd. -211", "Aron oxetane OXT-221", "Aron oxetane OXT-212" and so on.

When the active energy ray-curable adhesive contains a cationically polymerizable compound such as an epoxy compound or an oxetane compound, the adhesive is usually formulated with a photocationic polymerization initiator. When a photocationic polymerization initiator is used, an adhesive layer can be formed at a normal temperature, so that deformation of the polarizing film due to heat resistance or expansion can be considered, and the polarizing film and the protective film can be attached with good adhesion. . Further, since the photocationic polymerization initiator is catalyzed by light, the above-mentioned adhesive agent in which the photocationic polymerization initiator is mixed is excellent in storage stability and workability.

The photocationic polymerization initiator is a polymerization initiator which initiates a cationically polymerizable compound by irradiation with an active energy ray such as visible light, ultraviolet light, X-ray or electron beam to generate a cationic species or a Lewis acid. The photocationic polymerization initiator may be of any type, but specific examples thereof include: an aromatic diazonium salt; an onium salt such as an aromatic onium salt or an aromatic onium salt; and an iron-aromatic hydrocarbon (arene) error. Compounds, etc.

Examples of the aromatic diazonium salt include the following compounds: benzene diazonium hexafluoroantimonate, benzene diazonium hexafluorophosphate, and benzene diazonium hexafluoroborate.

The aromatic sulfonium salt may, for example, be a compound of diphenyl hydrazine (pentafluorophenyl)borate, diphenyl sulfonium hexafluorophosphate, diphenyl sulfonium hexafluoroantimonate or bis(4-fluorenyl) hexafluorophosphate. Phenyl) oxime and the like.

The aromatic sulfonium salt may, for example, be a compound of the following: triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium quinone (pentafluorophenyl)borate, 4,4'-bis(diphenyl) Diphenyl sulfide dihexafluorophosphate, 4,4'-bis[bis(β-hydroxyethoxy)phenylindenyl]diphenyl sulfide dihexafluoroantimonate, 4, 4'-bis[bis(β-hydroxyethoxy)phenylindenyl]diphenyl sulfide dihexafluorophosphate, 7-[bis(p-tolyl)indolyl]-2-isopropylsulfan Anthrone hexafluoroantimonate, 7-[bis(p-tolyl)indolyl]-2-isopropylthioxanthone oxime (pentafluoro Phenyl)borate, 4-phenylcarbonyl-4'-diphenylfluorenyl-diphenyl sulfide hexafluorophosphate, 4-(p-tert-butylphenylcarbonyl)-4'-diphenyl Benzyl-diphenyl sulfide hexafluoroantimonate, 4-(p-tert-butylphenylcarbonyl)-4'-di(p-tolyl)indenyl-diphenyl sulfide quinone (pentafluorobenzene) Base) borate or the like.

Further, the iron-aromatic complex compound can be exemplified by the following compounds. Xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, xylene-cyclopentadienyl iron (II) ginseng ( Trifluoromethylsulfonyl) methanide and the like.

Such a photo-cationic polymerization initiator can be easily obtained as a commercial product, and for example, "Kayarad PCI-220" and "Kayarad PCI-620" sold by Nippon Kayaku Co., Ltd., respectively, by the trade name; "UVI-6990" sold by Union Carbide; "UVACURE 1590" sold by Daicel Cytec; "Adeka optomer SP-150" and "Adeka optomer SP-" sold by ADEKA 170"; "CI-5102", "CIT-1370", "CIT-1682", "CIP-1866S", "CIP-2048S" and CIP-2064S" sold by Japan's Soda Co., Ltd.; "DPI-101", "DPI-102", "DPI-103", "DPI-105", "MPI-103", "MPI-105", "BBI-101", which are sold by Chemicals Co., Ltd. "BBI-102", "BBI-103", "BBI-105", "TPS-101", "TPS-102", "TPS-103", "TPS-105", "MDS-103", "MDS -105", "DTS-102" and "DT-103"; "PI-2074" sold by Rhodia.

These photocationic polymerization initiators may be used alone or in combination of two or more. Among these, in particular, the aromatic sulfonium salt has ultraviolet absorbing properties even in a wavelength region of 300 nm or more, so that it is excellent in curability, imparts good mechanical strength, and can be provided with a polarizing film and a protective film. It is better to use a hardened material with good adhesion.

The amount of the photocationic polymerization initiator is relative to the inclusion of an epoxy compound or The total amount of the cationically polymerizable compound of the oxetane compound is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, based on 100 parts by weight. When the amount of the photocationic polymerization initiator is small, the curing is insufficient, and the mechanical strength or the adhesion between the polarizing film and the protective film tends to be lowered. On the other hand, if the amount of the photocationic polymerization initiator is too large, the ionic substance in the hardened material is increased, so that the hygroscopicity of the cured product is made high, and the resulting adhesive layer may be made durable. Performance is reduced.

Further, the active energy ray-curable adhesive may further contain a radical polymerizable (meth)acrylic acid while containing the epoxy compound or an epoxy compound and an oxetane compound. Compound. By using a (meth)acrylic compound in combination, an effect of improving the hardness or mechanical strength of the adhesive layer can be expected, and further, the viscosity of the curable adhesive, the curing rate, and the like can be more easily adjusted. The (meth)acrylic compound may be the same as the active energy ray-curable resin composition forming the above-mentioned adhesive layer.

The adhesive agent constituting the second adhesive layer 32 and/or the third adhesive layer 33 may contain an optional component as needed. Such an optional component is, for example, the same as that described previously in the composition of the curable resin composition constituting the adhesive layer 31 for bonding the first retardation film 10 and the second retardation film 18. By.

[Liquid crystal display panel and liquid crystal display device]

The composite polarizing plate 50 of the present invention configured as described above can be bonded to the liquid crystal cell via the adhesive layer 46 to form a liquid crystal display panel, and the adhesive layer 46 is formed on the composite phase difference plate 20 and adhered to the polarized light. The surface on the opposite side of the surface of the film 42, that is, the exposed surface of the first phase difference plate 10. This liquid crystal panel is combined with a backlight or the like to form a liquid crystal display device. In the configuration shown in Fig. 2, the separator 48 provided on the surface of the adhesive layer 46 is peeled off before being bonded to the liquid crystal cell. Liquid crystal cell The composite polarizing plate 50 of the present invention is disposed on both sides to form a liquid crystal panel, and the composite polarizing plate 50 of the present invention may be disposed on one surface of the liquid crystal cell to constitute a liquid crystal panel. In the latter case, another polarizing plate is generally disposed on the liquid crystal cell surface on which 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, when the composite polarizing plate 50 of the present invention is disposed on one surface of the liquid crystal cell, the phase difference Re of the transparent protective film in the liquid crystal cell side of the polarizing plate disposed on the other surface is preferably 10 nm. Hereinafter, the absolute value of the phase difference Rth in the thickness direction is preferably 15 nm or less. More preferably, the in-plane retardation Re is 5 nm or less, and the absolute value of the phase difference Rth in the thickness direction is 10 nm or less.

An example of a material for a transparent protective film having an in-plane retardation Re of 10 nm or less and an absolute value of a phase difference Rth in the thickness direction of 15 nm or less is a cellulose resin or a cyclic olefin resin. Acrylic resin, polyethylene terephthalate resin, polypropylene resin, or the like. As long as the phase difference between the in-plane and the thickness direction is appropriately selected from the film composed of such a resin, it is sufficient.

Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. In the examples, the % or the part of the content or the amount used is a weight basis unless otherwise stated. Further, the phase difference and the Nz coefficient of the film are values measured at a wavelength of 590 nm. First, a production example of a first phase difference plate having a (meth)acrylic resin layer is shown.

[Manufacturing Example 1] Production of First Phase Difference Plate Having a Methacrylic Resin Layer

As the resin of the phase difference display layer 12, a styrene-matrix sold under the trade name "Dylark D332" by Nova Chemical Co., Ltd. and having a glass transition temperature of 131 ° C was used. The anhydride is a copolymerized resin. Further, as the resin of the (meth)acrylic resin layers 14 and 15, about 20% of acrylic rubber particles having an average particle diameter of 200 μm used in "Technolloy S001" sold by Sumitomo Chemical Co., Ltd. are used. The glass transition temperature was 105 ° C methacrylic resin. Then, a three-layer co-extrusion was carried out to form a layer composed of a methacrylic resin on both sides of a layer composed of a styrene-maleic anhydride-based copolymer resin to prepare a styrene-maleic anhydride system. A resin film having a three-layer structure in which the thickness of the layer composed of the copolymerized resin was 80 μm and the thickness of the methacrylic resin layer formed on both surfaces was 40 μm. The resin film of the three-layer structure was stretched, and the thickness of the phase difference display layer 12 was 40 μm, and the thickness of the methacrylic resin layers 14 and 15 was 20 μm, respectively, and the total thickness was 80 μm. board. The phase difference plate has an in-plane phase difference of 47.3 nm and an Nz coefficient of -1.06.

Next, a production example of an adhesive composed of a curable resin composition used when the first retardation film produced as described above is adhered to a second retardation film made of a cycloolefin-based resin film is shown.

[Manufacturing Example 2] Modification of Curable Resin Composition A

N-(2-hydroxyethyl) acrylamide, methyl acrylate, sold under the trade name "Irgacure 907" by BASF Corporation and chemical name 2-methyl-1-[4-(methylthio) A photoradical polymerization initiator of phenyl]-2-morpholinopropan-1-one and a polyfluorene-based leveling agent sold by Toray Dow Corning under the trade name "SH710" are as follows The ratio is mixed to prepare a curable resin composition A. The above "Irgacure 907" is abbreviated as "photoradical polymerization initiator "Irgacure 907"". Further, the above "SH710" is abbreviated as "polyoxane-based leveling agent" SH710".

Curable resin composition A

[Production Examples 3 and 4] Modification of Curable Resin Compositions B and C

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

Curable resin composition B

Curable resin composition C

[Manufacturing Example 5] Modification of Curable Resin Composition X

The curable resin composition X was adjusted 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 100 parts. The blending amount of the curable resin composition X is as follows.

Curable resin composition X

100 parts of N-(2-hydroxyethyl) acrylamide

[Manufacturing Example 6] Modification of Curable Resin Composition Y

An epoxy compound sold by Daicel (trade name) under the trade name "Celloxide 2021P" and chemically known as 3,4-epoxycyclohexanecarboxylic acid 3,4-epoxycyclohexylmethyl ester, synthesized from East Asia (Stock) oxetane compound sold under the trade name "Aron oxetane OXT-221" and chemically named bis(3-ethyl-3-oxetanylmethyl)ether, by Daicel Cytec 4,4'-bis(diphenylfluorenyl)diphenyl sulfide bishexafluorophosphate-based photocationic polymerization initiator sold under the trade name "UVACURE 1590", and polyfluorene oxide The leveling agent "SH710" was mixed in the following ratio to prepare a curable resin composition X. The above "Celloxide 2021P" is abbreviated as "epoxy compound "Celloxide 2021P"", and is further abbreviated as "CEL 2021P" in the table. The above "Aron oxetane OXT-221" is abbreviated as "oxetane compound OXT-221", and is further referred to as "OXT-221" in the table. The above "UVACURE 1590" is abbreviated as "photocationic polymerization initiator" UVACURE 1590".

Curable resin composition Y

Next, the first retardation film made of the cycloolefin-based resin was bonded to the first retardation film produced in Production Example 1 using the curable resin composition prepared in Production Examples 2 to 6, and the composite phase difference was produced. Examples and comparison examples of the plates.

[Example 1]

A phase difference plate composed of a stretched film of a cycloolefin resin having a thickness of 25 μm [Zeonor film sold by Zeon Co., Ltd., in-plane phase difference = 90 nm, thickness direction retardation = 79 nm] was used as the first The two-phase retardation plate was coated with the curable resin composition A produced by the manufacturing example 2 on the one surface by the coater [the first physicochemical (bar) bar coater]. When the film thickness of the curable resin composition was changed depending on the viscosity, the number of the wire code of the bar coater was changed, and the film thickness after hardening was adjusted to 7 μm. Then, on the other surface of the first retardation film produced in Production Example 1, the cycloolefin-based resin film of the coating film of the curable resin composition A was formed so that the coating film side became the first phase difference. The bonding surface of the board is attached by using a sticking device ["LPA3301" manufactured by Fujipla Co., Ltd.]. In the case of the above-mentioned bonded product, the ultraviolet ray irradiation device with the conveyor belt (the lamp system is "D bulb" manufactured by Fusion UV Systems Co., Ltd.) from the side of the cycloolefin-based resin film, and the integrated light amount is 250 mJ/cm ² . Ultraviolet rays are irradiated to cure the curable resin composition to prepare a composite phase difference plate.

[Examples 2 and 3]

A composite retardation film was produced in the same manner as in Example 1 except that the film thickness after curing of the curable resin composition was adjusted to 5 μm and 3 μm.

[Examples 4 to 6]

In the same manner as in Examples 1 to 3 except that the curable resin composition B prepared in Production Example 3 was used instead of the curable resin composition A, three kinds of composite phase differences in the thickness of the adhesive layer were produced. board.

[Examples 7 and 8]

In the same manner as in Examples 2 and 3 except that the curable resin composition C prepared in Production Example 4 was used instead of the curable resin composition A, a composite phase difference of two types of adhesive film thicknesses was produced. board.

[Comparative Examples 1 to 3]

In the same manner as in Examples 1 to 3 except that the curable resin composition X prepared in Production Example 5 was used instead of the curable resin composition A, three kinds of composite phase differences in the thickness of the adhesive layer were produced. board.

[Comparative Examples 4 to 6]

In the same manner as in Examples 1 to 3 except that the curable resin composition Y prepared in Production Example 6 was used instead of the curable resin composition A, three kinds of composite phase differences in the thickness of the adhesive layer were produced. board.

[Comparative Example 7]

One side of the stretched cycloolefin-based resin film having a thickness of 25 μm which was the same as that of the user of Example 1 was subjected to corona treatment, and an acrylic pressure-sensitive adhesive sheet having a thickness of 15 μm was bonded thereto. In addition, a corona treatment was applied to one surface of the first retardation film produced in Production Example 1, and the surface was bonded to the surface of the acrylic pressure-sensitive adhesive which was opposite to the stretched cycloolefin resin film to prepare a composite retardation film.

[Next force evaluation test]

The surface of the cycloolefin-based resin film of the composite retardation film produced in Examples 1 to 8 and Comparative Examples 1 to 7 was subjected to corona treatment, and then an acrylic pressure-sensitive adhesive sheet was bonded to the treated surface thereof, and attached thereto. Composite phase difference plate for adhesives. A test piece having a width of 25 mm and a length of about 200 mm was cut from the obtained composite phase difference plate with an adhesive, and the adhesive surface was attached to the soda glass, and the pressure was 5 kgf/cm ² in a pressure cooker at a temperature of 50 ° C. The pressure treatment was carried out for 20 minutes, and the mixture was further aged at a temperature of 23 ° C and a relative humidity of 60% for 1 day.

In this state, use the universal tensile tester [AG-1" manufactured by Shimadzu Corporation, and grab the 3 in the longitudinal direction of one side of the test piece (one side of the width of 25 mm). The first phase difference plate of the layer structure is subjected to a crosshead speed (catch moving speed) of 200 mm/min in an environment of a temperature of 23 ° C and a relative humidity of 60%, in accordance with JIS K6854-1: 1999. - 90° peeling test of the peeling strength test method - Part 1: 90 degree peeling", the second phase difference between the first phase difference plate containing the methacrylic resin layer and the cycloolefin resin film was evaluated. The adhesion between the plates. The results are shown in Table 1. In Table 1, in the column of "adhesion force", "material destruction" means that the adhesive layer of the first retardation film and the second phase difference plate is not peeled off in the peeling test. A layer of a phase difference plate and/or a second phase difference plate has been destroyed.

(Remarks)

HEAA: N-(2-hydroxyethyl) acrylamide

MA: Methyl acrylate

CEL 2021P: Epoxy compound "Celloxide 2021P"

OXT-221: oxetane compound "Aron Oxetane OXT-221"

As shown in Table 1, the first phase difference plate and the second phase difference plate were adhered by using a mixture of N-(2-hydroxyethyl) acrylate and methyl acrylate as an adhesive for the curable component. We increase the adhesion force while we are thinning. Further, when an adhesive of a mixture of an epoxy compound and an oxetane compound as a curable component is used for adhesion between the first phase difference plate and the second phase difference plate (Comparative Examples 4 to 6), Get enough adhesion.

10‧‧‧First phase difference plate

12‧‧‧ phase difference display layer

14, 15‧‧‧ (meth)acrylic resin layer

18‧‧‧Second phase difference plate

20‧‧‧Composite phase difference plate

31‧‧‧ adhesive layer

Claims (8)

A composite phase difference plate comprising: on the (meth)acrylic resin layer having a first phase difference plate of a (meth)acrylic resin layer on an outermost surface, sequentially laminated and hardened by an active energy ray The adhesive layer formed of the cured product of the resin composition and the second retardation film formed of the cycloolefin resin film, wherein the active energy ray-curable resin composition contains N-substituted (methyl) The acrylamide and a compound having a (meth)acryloxy group in the molecule are used as a curable component, and the adhesive layer has a thickness of 10 μm or less; and the N-substituted (meth)acrylamide is as follows ( I): In the formula, 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 together with Q ₃ Forming a 5-membered ring or a 6-membered ring which may have an oxygen atom as a ring-constituting member with the nitrogen atom to which the bond is bonded; the aforementioned compound having a (meth)acryloxy group is represented by the following formula (II) (A) Alkyl acrylate: In the formula, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group having 1 to 6 carbon atoms; and the active energy ray-curable resin composition contains the following formula (I) based on the total amount of the curable component. The N-substituted (meth) acrylamide shown is 60 to 80% by weight and the alkyl (meth) acrylate represented by the following formula (II) is 40 to 20% by weight. The composite phase difference plate according to the first aspect of the invention, wherein the first phase difference plate contains a phase difference display layer containing another resin in addition to the (meth)acrylic resin layer. The composite phase difference plate according to claim 2, wherein the phase difference display layer has a glass transition temperature of 120 ° C or higher, and the (meth)acrylic resin layer has a glass transition temperature of 120 ° C or lower. . The composite phase difference plate according to the first or second aspect of the invention, wherein the phase difference display layer comprises a styrene resin. The composite phase difference plate according to any one of the first aspect, wherein the (meth)acrylic resin layer contains rubber particles. The composite phase difference plate according to any one of the first aspect of the invention, wherein the first phase difference plate is formed on the both sides of the phase difference display layer to form the (meth)acrylic resin layer. . The composite phase difference plate according to claim 6, wherein the phase difference display layer and the (meth)acrylic resin layer formed on both sides thereof have a thickness of 10 to 100 μm. A composite polarizing plate which is formed by laminating a protective film containing a thermoplastic resin via a second adhesive layer on a surface of a polarizing film in which a polyvinyl alcohol-based resin is adsorbed and has a dichroic dye, and is polarized thereon. On the other side of the film, the composite retardation film according to any one of the first to seventh aspects of the invention is laminated on the side of the cycloolefin resin film.