KR20190053785A - Composite retardation plate, optical laminate and image display device - Google Patents

Abstract

An object of the present invention is to provide a composite retardation plate in which generation of wrinkles in a bent portion is suppressed even when the composite retardation plate is bent, by being brought into contact with a roll-shaped member or disposed on the surface of an image display device panel having the bent portion in a process of conveying, winding, and the like. The object includes a first retardation layer, a second retardation layer, and a first adhesive layer that bonds the first retardation layer and the second retardation layer, and the problem is solved by a composite retardation plate having a piercing slope per unit film thickness of 6 kg/mm^2 to 15 kg/mm^2.

Description

Technical Field [0001] The present invention relates to a composite retardation plate, an optical laminate, and an image display device,

The present invention relates to a composite retardation plate, an optical laminate including the composite retardation plate, and an image display apparatus including the optical laminate.

Conventionally, in an image display apparatus, a method of disposing an optical laminate having antireflection performance on a visual side of an image display panel to suppress deterioration of visibility due to reflection of foreign light has been adopted.

As an optical laminate having antireflection performance, an optical laminate composed of a polarizing plate and a retardation layer is known. In the optical laminate having the antireflection performance, the outgoing light directed to the image display panel is converted into linearly polarized light by a polarizing plate and converted into circularly polarized light by a subsequent phase difference layer. The outgoing light, which is circularly polarized light, is reflected on the surface of the image display panel, but the direction of rotation of the polarization plane is reversed during the reflection, converted into linearly polarized light by the retardation layer, and then shielded by the succeeding polarizing plate. As a result, emission to the outside is remarkably suppressed.

As a retardation plate that is a component of an optical laminate having antireflection properties, a compound retardation plate comprising a plurality of retardation layers adhered with an adhesive layer is known. For example, Patent Documents 1 and 2 disclose a composite retardation plate in which a 1/2 wavelength layer and a 1/4 wavelength layer are adhered with an adhesive layer.

Patent Document 1: JP-A-2015-21975 Patent Document 2: JP-A-2015-21976

The composite retardation plate is an optical laminate that is used alone or in combination with the composite retardation plate when the compound retardation plate is bent by being brought into contact with the roll-shaped member or disposed on the surface of the image display panel having the bent portion in the process of carrying, , There is a possibility that wrinkles occur at the bent portion, which may cause quality problems. Particularly, in the case where the composite retarder is formed of a thin film, there is a case where it is remarkable.

INDUSTRIAL APPLICABILITY The present invention is applicable to a composite in which occurrence of wrinkles in the bent portion is suppressed even when the composite retardation plate is bent by being brought into contact with the roll-shaped member or disposed on the surface of the image display panel having the bent portion in the process of carrying, A retardation plate, an optical laminate including the compound retarder, and an image display device including the optical laminate.

The present invention provides the following composite retardation plate, optical laminate, and image display device.

[1] A liquid crystal display comprising a first retardation layer, a second retardation layer, and a first adhesive layer for bonding the first retardation layer and the second retardation layer,

A composite retardation plate having a stiction slope of 6 kg / mm < 2 > to 15 kg / mm < 2 > per unit film thickness.

[2] The compound retarder according to [1], wherein the first adhesive layer is a cured layer of an active energy ray curable adhesive.

[3] The compound retarder according to [1] or [2], wherein the first retardation layer is a ½ wavelength layer and the second retardation layer is a ¼ wavelength layer.

[4] The compound retarder according to [1] or [2], wherein the first retardation layer is a 1/2 wavelength layer or a 1/4 wavelength layer and the second retardation layer is an optical compensation layer.

[5] The compound retarder as described in any one of [1] to [4], wherein at least one of the first retardation layer and the second retardation layer comprises a retardation developing layer which is a liquid crystal layer.

[6] The compound retarder according to any one of [1] to [5], wherein the thickness is 2 μm to 50 μm.

[7] A polarizing plate comprising the polarizing plate and the compound retardation plate according to any one of [1] to [6] laminated on the polarizing plate,

Wherein the compound retarder is laminated in a direction in which the first retardation layer is located on the polarizing plate side.

[8] The optical laminate according to [7], which is a circularly polarizing plate.

[9] The optical laminate according to [7] or [8], further comprising a second adhesive layer for bonding the polarizing plate and the compound retarder.

[10] The optical laminate according to [9], wherein the second adhesive layer is a cured layer of an active energy ray-curable adhesive.

[11] An image display device comprising an image display panel and an optical laminate according to any one of [7] to [10] arranged on the visual side of the image display panel.

[12] The image display apparatus according to [11], wherein the optical laminate is disposed in a direction in which the polarizing plate is positioned on the viewer side.

[13] An image display device according to [12], which is an organic electroluminescence display device.

According to the composite retarder of the present invention, even when the composite retarder is bent by being brought into contact with the roll-shaped member or disposed on the surface of the image display panel having the bent portion in the process of carrying and winding, Generation can be suppressed.

1 is a schematic cross-sectional view schematically showing an example of a composite retardation plate of the present invention.
Fig. 2 is a schematic cross-sectional view schematically showing an example of a retardation layer having a liquid crystal layer as a retardation-releasing layer.
3 (A) to 3 (C) are schematic cross-sectional views schematically showing one example of each manufacturing step in the method for producing a composite retardation plate of the present invention.

Hereinafter, the compound phase difference plate and the optical laminate of the present invention will be described with reference to the drawings.

[Composite retardation plate]

1 is a schematic cross-sectional view schematically showing an example of a composite retardation plate of the present invention. 1, the compound retardation film 5 has a structure in which a first retardation layer 1, a second retardation layer 2, a first retardation layer 1 and a second retardation layer 2 And a first adhesive layer 4 for bonding. The compound phase difference plate 5 preferably has a slope inclination per unit film thickness of 6 kg / mm 2 to 15 kg / mm 2, preferably 6 kg / mm 2 to 12 kg / mm 2, more preferably 6.5 to 10 kg / More preferably 7 kg / mm 2 to 10 kg / mm 2, and particularly preferably 8 kg / mm 2 to 10 kg / mm 2. Since the slope inclination per unit film thickness is 6 kg / mm < 2 > or more, the occurrence of wrinkles can be suppressed even when the composite retardation plate 5 or the optical laminate including the composite retardation plate 5 is bent. When the stiction inclination per unit film thickness of the composite retardation plate 5 exceeds 15 kg / mm 2, fine cracks easily enter the end portions of the composite retardation plate or the optical laminate including the composite retardation plate 5 during processing such as cutting.

The stippling slope of the composite retardation plate indicates the intensity when the stiction jig is vertically pushed against the composite retardation plate to tear the composite retardation plate. The striking slope can be calculated from the stuck strength, and the striking strength can be measured using, for example, a small tablet machine (trade name "EZ Test", manufactured by Shimadzu Seisakusho Co., Ltd.).

The measurement of the stuck strength is carried out by sandwiching a compound phase difference plate between two sample pores having circular holes each having a diameter of 15 mm or less through which the stuck jig can pass. It is preferable that the prick jig is a columnar rod, and the prick needle having a spherical or hemispherical tip at its tip in contact with the composite retarder is provided. The spherical portion or hemispherical portion at the tip end is preferably 0.5 mm or more in diameter and 5 mm or less in diameter. It is also preferable that the radius of curvature is larger than 0 R and smaller than 0.7 R. The sticking speed of the sticking jig is 0.05 cm / sec or more, preferably 0.5 cm / sec or less.

The striking strength is measured by fixing the test piece to a jig, stuck in the normal direction of the main surface of the compound retarder, and measuring the strength when the stub is torn at one place. The stiction intensity A (kg) obtained at this time, the stuck depth B (mm) to be torn and the composite retardation plate thickness d (mm)

E = A / (B x d)

Is used to calculate the steeper slope E (kg / mm < 2 >) per unit film thickness. The stippling slope of the composite retarder is an average value of the steeper slopes E of five or more composite retarder plates manufactured under the same conditions.

The compound phase difference plate 5 may be formed by, for example, contacting the compound phase difference plate 5 or the optical laminate including the compound phase difference plate 5 with a roll type member such as a conveyance roll or a winding roll in a process of conveying, The composite retardation plate 5 according to the present invention can prevent the first retardation layer 1 and / or the second retardation layer 2 from being wrinkled when the compound retardation plate is bent by, for example, Can be suppressed.

From the viewpoint of thinning, the thickness of the composite retardation plate 5 is preferably 1 m to 100 m, more preferably 1 m to 50 m, and still more preferably 2 m to 50 m.

<First retardation layer and second retardation layer>

The first retardation layer (1) and the second retardation layer (2) are not particularly limited as long as they are retardation layers containing at least one retardation layer for imparting a predetermined retardation to light. For example, / 4 wavelength layer, a positive C plate, or the like, or a retardation layer having an inverse wavelength dispersion. Particularly, in the case of a retardation layer having a reverse dispersion property, since transmission of light at any wavelength is suppressed, the retardation layer is effective as an optical laminate having antireflection performance. The first retardation layer (1) and the second retardation layer (2) may be composed only of the retardation layer or may include another layer together with the retardation layer, as long as the retardation layer includes at least one retardation layer. Examples of other layers include a base layer, an orientation film layer, and a protective layer. Further, the other layer does not affect the value of the retardation.

Examples of the phase difference-generating layer include a layer formed by using a liquid crystal compound (hereinafter referred to as a &quot; liquid crystal layer &quot;) or a stretched film. It is preferable that at least one of the first retardation layer 1 and the second retardation layer 2 is a liquid crystal layer from the viewpoint of thinning of the composite retardation plate and both liquid crystal layers are more preferable . The retardation layer as a liquid crystal layer is generally thinner than the retardation layer as a stretched film. The first retardation layer (1) and the second retardation layer (2) preferably have a thickness of 0.5 탆 to 10 탆, more preferably 0.5 탆 to 5 탆. When the first retardation layer and the second retardation layer each include another layer (base layer, orientation film layer, protective layer, etc.) other than the retardation layer, the thickness of the whole is preferably 0.5 to 300 占 퐉, More preferably 0.5 to 150 占 퐉.

When the composite retardation plate is bent as the thicknesses of the first retardation layer 1 and the second retardation layer 2 are reduced, the refractive index of the first retardation layer 1 and the second retardation layer 2 The composite retardation plate of the present invention suppresses the occurrence of wrinkles even when the first retardation layer 1 and the second retardation layer 2 are as thin as 5 占 퐉 or less as described above can do.

As the combination of the first retardation layer (1) and the second retardation layer (2) in the compound retarder of the present invention, for example,

i) a combination of a 1/2 wavelength layer and a 1/4 wavelength layer,

ii) a combination of the 1/2 wavelength layer and the optical compensation layer,

iii) a combination of a quarter wavelength layer and an optical compensation layer,

iv) a combination of a back-scattering 1/4 wavelength layer and an optical compensation layer

And the like.

The 1/2 wavelength layer has a function of changing the direction (polarization direction) of linearly polarized light by giving a phase difference of? (=? / 2) to the electric field oscillation direction (polarization plane) of incident light. When the circularly polarized light is incident, the rotation direction of the circularly polarized light can be reversed.

The 1/2 wavelength layer is a layer in which Re (?) Which is an in-plane retardation value at a specific wavelength? Nm satisfies Re (?) =? / 2. Re (lambda) = lambda / 2 at any wavelength in the visible light region can be attained, but it is preferable that attainable at a wavelength of 550 nm. The in-plane retardation value Re (550) at a wavelength of 550 nm preferably satisfies 210 nm? Re (550)? 300 nm. Further, it is more preferable that 220 nm &amp;le; Re (550) &amp;le;

The retardation value Rth (550) in the thickness direction of the half-wave layer measured at a wavelength of 550 nm is preferably -150 to 150 nm, more preferably -100 to 100 nm.

The 1/4 wavelength layer imparts a phase difference of? / 2 (=? / 4) to the electric field oscillation direction (polarization plane) of the incident light so that linearly polarized light of a certain wavelength is converted into circularly polarized light ).

The quarter wavelength layer is a layer that satisfies Re (?) =? / 4, which is an in-plane retardation value at a specific wavelength? Nm, and may be attained at any wavelength in the visible light region, Preferably at 550 nm. The in-plane retardation value Re (550) at a wavelength of 550 nm preferably satisfies 100 nm? Re (550)? 160 nm. Further, it is more preferable that 110 nm? Re (550)? 150 nm is satisfied.

The retardation value Rth (550) in the thickness direction of the? / 4 wavelength layer measured at a wavelength of 550 nm is preferably -120 nm to 120 nm, more preferably -80 nm to 80 nm.

Examples of the optical compensation layer include a positive A plate and a positive C plate. The positive A plate has a relationship of Nx > Ny when the refractive index in the slow axis direction in the plane is Nx, the refractive index in the fast axis direction in the plane is Ny, and the refractive index in the thickness direction is Nz It is satisfied. It is preferable that the positive A plate satisfy the relationship of Nx > Ny > Nz. The positive A plate can also function as a 1/4 wavelength layer. The positive C plate satisfies the relationship of Nz &gt; Nx &gt;

The inverse wavelength dispersion is an optical characteristic in which the liquid crystal in-plane retardation value at a short wavelength is smaller than the in-plane retardation value at the long wavelength in the long wavelength,

Re (450)? Re (550)? Re (650) (a)

. In addition, Re (?) Represents the in-plane retardation value for the light of the wavelength? Nm.

The optical characteristics of the retardation layer can be controlled by the orientation state of the liquid crystal compound constituting the retardation developing layer or the stretching method of the stretched film constituting the retardation developing layer. By appropriately controlling the optical characteristics of the retardation layer, the composite retardation plate 5 and the polarizing plate are laminated to obtain an optical laminate having antireflection performance. In the optical laminate referred to in the present specification, the polarizing plate and the compound retarder 5 are laminated, and the compound retarder 5 is laminated in the direction in which the first retardation layer 1 is located on the polarizing plate side . Even when the same compound retarder 5 is used, the optical characteristics of the ordinary optical laminate are different when the lamination direction of the composite retarder 5 is reversed.

(Phase difference-generating layer formed of a liquid crystal layer)

The case where the phase difference-generating layer is a liquid crystal layer will be described. 2 is a schematic cross-sectional view schematically showing an example of a retardation layer including a retardation layer which is a liquid crystal layer and another layer. 2, the retardation layer 30 is formed by laminating a base layer 31, an orientation layer 32, and a retardation layer 33, which is a liquid crystal layer, in this order. The retardation layer is not limited to the retardation layer 30 shown in Fig. 2 as long as it includes the retardation layer 33 which is a liquid crystal layer and the base layer 31 is peeled off from the retardation layer 30 to form the alignment layer 32 and the phase difference manifestation layer 33 as the liquid crystal layer may be constituted by only the retardation layer 33 constituting the liquid crystal layer and the base layer 31 and the orientation layer 32 separated from the retardation plate 30 . From the viewpoint of thinning, the retardation layer preferably has a structure in which the base layer 31 is peeled off, more preferably a constitution comprising only the retardation layer 33 which is a liquid crystal layer. The base layer 31 functions as an orientation layer 32 formed on the base layer 31 and as a support layer for supporting the phase difference-generating layer 33. The substrate layer 31 is preferably a film formed of a resin material.

As the resin material, for example, a resin material excellent in transparency, mechanical strength, thermal stability, stretchability and the like is used. Specifically, polyolefin-based resins such as polyethylene and polypropylene; Cyclic polyolefin-based resins such as norbornene-based polymers; Polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (Meth) acrylic acid-based resins such as (meth) acrylic acid and poly (meth) acrylate; Cellulose ester-based resins such as triacetylcellulose, diacetylcellulose and cellulose acetate propionate; Vinyl alcohol-based resins such as polyvinyl alcohol and polyvinyl acetate; Polycarbonate resin; Polystyrene type resin; Polyarylate resins; Polysulfone resins; Polyether sulfone type resin; Polyamide based resin; Polyimide resin; Polyether ketone resin; Polyphenylene sulfide type resin; Polyphenylene oxide-based resins, and mixtures and copolymers thereof. Among these resins, it is preferable to use any of a cyclic polyolefin resin, a polyester resin, a cellulose ester resin and a (meth) acrylic acid resin or a mixture thereof. The term &quot; (meth) acrylic acid &quot; means &quot; at least one of acrylic acid and methacrylic acid &quot;.

The substrate layer 31 may be a single layer obtained by mixing one kind of the resin or two or more kinds of the above resins, or may have a multilayer structure of two or more layers. In the case of having a multilayer structure, the resins constituting each layer may be the same or different.

An optional additive may be added to the resin material constituting the resin film. Examples of the additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments and colorants.

The thickness of the base layer 31 is not particularly limited, but it is preferably 5 to 200 占 퐉, more preferably 10 to 200 占 퐉, and more preferably 10 to 150 占 퐉 in view of workability such as strength and handling properties Is more preferable.

A corona treatment, a plasma treatment, a flame treatment, or the like may be performed on at least the surface of the base layer 31 on which the alignment layer 32 is formed in order to improve the adhesion between the base layer 31 and the alignment layer 32 , A primer layer or the like may be formed. When the base layer 31 or the base layer 31 and the orientation layer 32 are peeled off to form a phase difference layer, peeling can be facilitated by adjusting the adhesion at the peeling interface.

The alignment layer 32 has an alignment regulating force for aligning the liquid crystal compound contained in the phase difference reproduction layer 33, which is a liquid crystal layer formed on the alignment layer 32, in a desired direction. As the orientation layer 32, for example, an orientation polymer layer formed of an orientation polymer, a photo-orientable polymer layer formed of a photo-alignment polymer, and a groove orientation layer having an uneven pattern or groove (groove) on the surface of the layer. The thickness of the orientation layer 32 is usually 0.01 to 10 占 퐉, preferably 0.01 to 5 占 퐉.

The oriented polymer layer can be formed by applying a composition obtained by dissolving the oriented polymer in a solvent to the base layer 31, removing the solvent, and rubbing if necessary. In this case, in the oriented polymer layer formed of the oriented polymer, the orientation regulating force can be arbitrarily adjusted depending on the surface state and the rubbing condition of the oriented polymer.

The photo-orientable polymer layer can be formed by applying a composition containing a photo-reactive group-containing polymer or monomer and a solvent to the base material layer 31 and irradiating with polarized light. In this case, in the photo-orientable polymer layer, the alignment regulating force can be arbitrarily adjusted by the polarization irradiation conditions for the photo-orientable polymer.

The groove orientation layer may be formed by, for example, a method of forming an uneven pattern by performing exposure and development through an exposure mask having a pattern-shaped slit on the surface of the photosensitive polyimide film, a method of forming an active energy ray- Cured layer of the active energy ray-curable resin is formed on the base layer 31 by a method of transferring the layer to the base layer 31 and curing the base layer 31. A method of forming an uncured layer of the active energy ray- Or by forming a concavity and convexity by pressing the disk of the photoresist layer and curing the photoresist layer.

The phase difference developing layer 33, which is a liquid crystal layer, is not particularly limited as long as it imparts a predetermined retardation to the light. For example, the retardation layer 33 for the 1/2 wavelength layer, the retardation layer for the 1/4 wavelength layer, , A retardation layer for optical compensation layer, and a retardation layer for retardation layer having an opposite wavelength dispersion.

The phase difference developing layer 33, which is a liquid crystal layer, can be formed using a known liquid crystal compound. The kind of the liquid crystal compound is not particularly limited, and rod-shaped liquid crystal compounds, discotic liquid crystal compounds, and mixtures thereof can be used. The liquid crystal compound may be a polymer liquid crystal compound, a polymerizable liquid crystal compound, or a mixture thereof. As the liquid crystal compound, for example, Japanese Patent Publication Nos. 11-513019, 2005-289980, 2007-108732, 2010-244038, 2010-31223, Japanese Patent Application Laid-Open Nos. 2010-270108, 2011-6360, 2011-207765, 2016-81035, International Publication No. 2017/043438, and Japanese Patent Publication No. 2011-207765 And a liquid crystal compound described in JP-A-H05-29455.

For example, when a polymerizable liquid crystal compound is used, the phase difference-generating layer 33 can be formed by applying a composition containing a polymerizable liquid crystal compound on the alignment layer 32 to form a coating film and curing the coating film have. The thickness of the phase difference manifestation layer 33 is preferably 0.5 μm to 10 μm, more preferably 0.5 to 5 μm.

The composition containing the polymerizable liquid crystal compound may contain, in addition to the liquid crystal compound, a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, an adhesion improver, a plasticizer, and an alignment agent. As a coating method of a composition containing a polymerizable liquid crystal compound, known methods such as a die coating method can be mentioned. The curing method of the composition containing the polymerizable compound may be a known method such as irradiation of an active energy ray (for example, ultraviolet ray).

(A retardation plate having a stretched film as a phase difference developing layer)

The case where the retardation-developing layer is a stretched film will be described. The stretched film is usually obtained by stretching the base material. As a method for stretching the substrate, for example, a roll (roll) in which a substrate is wound on a roll is prepared, the substrate is continuously loosened from the roll, and the loosened substrate is conveyed to a heating furnace. The set temperature of the heating furnace is preferably in the range of the vicinity of the glass transition temperature (° C) to [glass transition temperature +100] (° C), preferably in the vicinity of the glass transition temperature (° C) ). In this heating furnace, when stretching in the advancing direction of the base material or in the direction orthogonal to the advancing direction, the uniaxial or biaxial hot-shrinking treatment is performed by tilting at an arbitrary angle by adjusting the conveying direction and the tension. The magnification of the stretching is usually 1.1 to 6 times, preferably 1.1 to 3.5 times.

The method of stretching in the oblique direction is not particularly limited as long as it can continuously tilt the orientation axis to a desired angle, and a known stretching method can be employed. Such a stretching method is, for example, a method described in JP-A-50-83482 or JP-A-2-113920. When retardation is imparted to the film by stretching, the thickness after stretching is determined by the thickness before stretching and the stretching magnification.

The substrate is usually a transparent substrate. Means a substrate having transparency capable of transmitting light, in particular, visible light, and transparency means a property that a transmittance to a light ray having a wavelength of 380 to 780 nm is 80% or more. As a specific transparent substrate, a translucent resin substrate can be mentioned. Examples of the resin constituting the light transmitting resin base material include polyolefins such as polyethylene and polypropylene; Cyclic olefin-based resins such as norbornene-based polymers; Polyvinyl alcohol; Polyethylene terephthalate; Polymethacrylic acid esters; Polyacrylic acid esters; Cellulose esters such as triacetylcellulose, diacetylcellulose, and cellulose acetate propionate; Polyethylene naphthalate; Polycarbonate; Polysulfone; Polyethersulfone; Polyether ketones; Polyphenylene sulfide, and polyphenylene oxide. From the viewpoint of availability and transparency, polyethylene terephthalate, polymethacrylic acid ester, cellulose ester, cyclic olefin resin or polycarbonate is preferable.

The cellulose ester is obtained by esterification of a part or all of the hydroxyl groups contained in the cellulose, and is easily available from the market. In addition, cellulose ester substrates are also readily available from the market. Commercially available cellulose ester bases include, for example, " Fuji-Takk (registered trademark) film " (FUJIFILM Corporation); , "KC8UX2M", "KC8UY" and "KC4UY" (Konica Minolta Opt).

Polymethacrylic acid esters and polyacrylic acid esters (hereinafter sometimes referred to as (meth) acrylic resins in combination of polymethacrylic acid esters and polyacrylic acid esters) are readily available from the market.

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

In order to further improve the mechanical strength, it is also preferable to include rubber particles in the (meth) acrylic resin. The rubber particles are preferably of acrylic type. Here, the acrylic rubber particles are rubber-elastic particles obtained by polymerizing an acrylic monomer mainly composed of an acrylic acid alkyl ester such as butyl acrylate or 2-ethylhexyl acrylate in the presence of a polyfunctional monomer. The acrylic rubber particles may be a single layer of such rubber-elastic particles, or a multi-layer structure having at least one rubber elastic layer. Examples of the acrylic rubber particles having a multilayer structure include those having rubber elastic particles as the core and covering the periphery thereof with a hard methacrylic acid alkyl ester polymer and hard acrylic rubber alkyl ester polymers having a hard methacrylic acid alkyl ester polymer as nuclei , The periphery of which is covered with an acrylic polymer having rubber elasticity as described above and the case where the periphery of the hard core is covered with a rubber elastic acrylic polymer and the periphery thereof is covered with a hard methacrylic acid alkyl ester polymer . The rubber particles formed of the elastic layer have an average diameter generally in the range of about 50 to 400 nm.

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

The cyclic olefin resin can be easily obtained from the market. Examples of commercial cycloolefin resins include "Topas" (registered trademark) [Ticona (Germany)], "Aton" (registered trademark) [JSR (registered trademark)], "ZEONOR" ZEONEX (registered trademark) (manufactured by Nippon Zeon Co., Ltd.) and APEL (registered trademark) manufactured by Mitsui Chemicals, Inc. can be mentioned. Such a cycloolefin resin can be formed into a substrate by a known means such as a solvent casting method or a melt extrusion method. A commercially available cycloolefin resin base material may also be used. Examples of commercially available cycloolefin resin base materials include "SESINA" (registered trademark) (Sekisui Chemical Industry Co., Ltd.), "SCA40" (registered trademark), "Sekisui Chemical Industry Co., (Trademark) OPTES Co., Ltd. and ARTON FILM (registered trademark) [JSR Co., Ltd.].

When the cyclic olefin resin is a copolymer of a cyclic olefin and an aromatic compound having a chain olefin or vinyl group, the content ratio of the structural unit derived from the cyclic olefin is usually 50 mol% or less based on the total structural units of the copolymer , Preferably from 15 to 50 mol%. Examples of the chain olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene,? -Methylstyrene, and alkyl-substituted styrene. When the cyclic olefin resin is a ternary copolymer of a cyclic olefin, a chain olefin and an aromatic compound having a vinyl group, the content ratio of the structural unit derived from the chain olefin is generally from 5 to 80 Mol%, and the content ratio of the structural unit derived from an aromatic compound having a vinyl group is usually 5 to 80 mol% based on the total structural units of the copolymer. Such a terpolymer has an advantage that the amount of the expensive cycloolefin used can be relatively small in the production thereof.

<First Adhesive Layer>

The first adhesive layer 4 is not particularly limited as long as it can achieve a stippling slope of 6 kg / mm &lt; 2 &gt; to 15 kg / mm &lt; 2 &gt; per unit film thickness of the composite retardation plate 5. Examples of the adhesive layer include an adhesive, Ray-curable adhesive, and combinations thereof. Among them, the first adhesive layer 4 is a cured layer of the active energy ray curable adhesive, so that it is easy to obtain the composite retardation plate 5 having the stippling slope of 6 kg / mm &lt; 2 &gt; The first adhesive layer 4 preferably has a thickness of 0.1 to 50 m, more preferably 0.1 to 10 m, and further preferably 0.5 to 5 m. In this specification, the term "first adhesive layer" includes not only an adhesive layer composed of an adhesive but also an adhesive layer composed of an adhesive.

A pressure-sensitive adhesive is generally obtained by radical polymerization of an acrylic monomer mixture containing a (meth) acrylic acid ester as a main component and a small amount of a (meth) acrylic monomer having a functional group in the presence of a polymerization initiator, and has a glass transition temperature An acrylic resin having a temperature of 0 占 폚 or less and an acrylic pressure-sensitive adhesive containing a crosslinking agent are preferably used.

The acrylic resin constituting the acrylic pressure-sensitive adhesive preferably has a weight average molecular weight (Mw) in terms of standard polystyrene by gel permeation chromatography (GPC) in the range of 1,000,000 to 2,000,000. If the weight average molecular weight (Mw) is more than 1,000,000, the adhesiveness under high temperature and high humidity is improved, and there is a tendency that the possibility of lifting or peeling between the glass substrate and the pressure-sensitive adhesive layer constituting the liquid crystal cell tends to decrease, It is preferable since the property tends to be improved. When the weight average molecular weight (Mw) of the acrylic resin is not more than 2,000,000, even if the size of the polarizing plate is changed, the pressure-sensitive adhesive layer follows and fluctuates following the dimensional change thereof, so that light leakage or color unevenness on the display tends to be suppressed . The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably in the range of 3 to 7.

The acrylic resin contained in the acrylic pressure-sensitive adhesive may be composed of only the relatively high molecular weight as described above, but may also be composed of a mixture with an acrylic resin different from the above acrylic resin. Examples of the acrylic resin which can be used in combination include those having a structural unit derived from a (meth) acrylate ester represented by the above formula (I) as a main component and having a weight average molecular weight in the range of 50,000 to 300,000 have.

A crosslinking agent is added to the acrylic resin thus obtained to form a pressure-sensitive adhesive. The crosslinking agent is a compound having at least two functional groups capable of performing a crosslinking reaction with a structural unit derived from a monomer having a polar functional group in an acrylic resin, and examples thereof include isocyanate compounds, epoxy compounds, metal chelate compounds, aziridine Compounds and the like.

As a method for forming the pressure-sensitive adhesive layer on the optical film of the present invention, for example, a method of applying a pressure-sensitive adhesive composition as described above to a pressure-sensitive adhesive layer using a release film as a substrate and transferring the obtained pressure- , A method of directly applying the above-mentioned pressure-sensitive adhesive composition on the surface of the optical film to form a pressure-sensitive adhesive layer, and the like. Alternatively, a pressure-sensitive adhesive layer may be formed on a single release film, and then a separate release film may be further adhered to the pressure-sensitive adhesive layer to form a pressure-sensitive adhesive double-side sheet. Such a double-faced separator type pressure-sensitive adhesive sheet is peeled off one of the release films at a necessary time, and is bonded onto the present optical film. Examples of commercially available double-sided separator type pressure-sensitive adhesive sheets include non-carrier pressure-sensitive adhesive films and non-carrier pressure-sensitive adhesive sheets sold by Nippon Oil,

As a water-based adhesive, for example, a polyvinyl alcohol-based resin or a urethane resin is used as a main component and a composition comprising a crosslinking agent such as an isocyanate compound or an epoxy compound or a curing compound is generally used in order to improve the adhesiveness.

When a polyvinyl alcohol resin is used as the main component of the water-based adhesive, in addition to partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, a carboxyl group-modified polyvinyl alcohol, an acetoacetyl group-modified polyvinyl alcohol, a methylol group-modified polyvinyl alcohol, A modified polyvinyl alcohol resin such as polyvinyl alcohol may be used. The aqueous solution of the polyvinyl alcohol-based resin is used as an aqueous adhesive. The concentration of the polyvinyl alcohol-based resin in the aqueous adhesive is usually 1 to 10 parts by mass, preferably 1 to 5 parts by mass, per 100 parts by mass of water.

In order to improve the adhesiveness as described above, a curable compound such as a polyvalent aldehyde, a water-soluble epoxy resin, a melamine compound, a zirconia compound and a zinc compound may be added to the aqueous adhesive composed of an aqueous solution of a polyvinyl alcohol resin . Examples of the water-soluble epoxy resin include water-soluble epoxy resins obtained by reacting epichlorohydrin with polyamide polyamines obtained by the reaction of polyalkylene polyamines such as diethylene triamine and triethylene tetramine with dicarboxylic acids such as adipic acid, Of a polyamide epoxy resin. As commercially available products of such polyamide epoxy resins, "Sumirez Resin 650" and "Sumirez Resin 675" sold by Sumika-Chemtech Co., Ltd., "WS-525" sold by Nippon PMC Co., have. When the water-soluble epoxy resin is blended, the addition amount thereof is usually about 1 to 100 parts by mass, and preferably 1 to 50 parts by mass based on 100 parts by mass of the polyvinyl alcohol-based resin.

When a urethane resin is used as the main component of the water-based adhesive, it is effective to use the polyester-based ionomer-type urethane resin as the main component of the water-based adhesive. The polyester-based ionomer-type urethane resin referred to herein is a urethane resin having a polyester skeleton, and a small amount of ionic component (hydrophilic component) is introduced into the urethane resin. Such an ionomeric urethane resin emulsifies directly in water without using an emulsifier to form an emulsion, so that an aqueous adhesive can be used. When a polyester-based ionomer-type urethane resin is used, it is effective to blend a water-soluble epoxy compound as a crosslinking agent. For example, Japanese Unexamined Patent Application Publication Nos. 2005-70140 and 2005-208456 disclose the use of a polyester-based ionomer-type urethane resin as an adhesive for a polarizing plate.

Each of these components constituting the water based adhesive is usually used in a state dissolved in water. An adhesive layer can be obtained by applying an aqueous adhesive on an appropriate substrate and drying it. The components that are not soluble in water may be dispersed in the system.

Examples of the method of forming the adhesive layer on the optical film include a method of directly applying the adhesive composition onto the surface of the optical film to form an adhesive layer.

In addition, for example, the obtained water-based adhesive may be injected between the polarizing plate and the optical film, and heated to progress the heat-crosslinking reaction while evaporating the water, thereby giving sufficient adhesiveness to both.

The active energy ray curable adhesive is not limited as long as it can cure upon irradiation with an active energy ray to obtain a composite retardation plate 5 having a slope gradient of 6 kg / mm &lt; 2 &gt; to 15 kg / mm &lt; 2 &gt; For example, a cationic polymerizable active energy ray curable adhesive containing an epoxy compound and a cationic polymerization initiator, a radically polymerizable active energy ray curable adhesive containing an acrylic cured component and a radical polymerization initiator, a cationically polymerizable curable component such as an epoxy compound, An active energy ray-curable adhesive containing both a cationic polymerization initiator and a radical polymerization initiator, and an actinic ray radiation-curable adhesive containing no initiator, which is cured by irradiating an electron beam, Adhesives, and the like. Preferably, it is a radically polymerizable active energy ray-curable adhesive containing an acrylic curing component and a radical polymerization initiator. Further, a cationic polymerizable active energy ray-curable adhesive containing an epoxy compound and a cationic polymerization initiator, which can be practically used as a solvent, is preferred.

A cationic polymerizable epoxy compound which itself is a liquid at room temperature and which has appropriate fluidity even without a solvent and which is given an appropriate curing adhesive strength is selected and an active energy ray curable adhesive containing an appropriate cationic polymerization initiator , The drying equipment which is usually required in the step of adhering the first retardation layer and the second retardation layer in the production facility of a compound retardation plate can be omitted. It is also possible to accelerate the curing rate and improve the production rate by irradiating an appropriate amount of active energy ray.

The epoxy compound to be used for such an adhesive may be, for example, a glycidyl ether compound of an aromatic compound or a chain compound having a hydroxyl group, a glycidyl amide compound of a compound having an amino group, an epoxide compound of a chain compound having a CC double bond, An alicyclic epoxy compound in which a glycidyloxy group or an epoxyethyl group is bonded directly to an alcian ring or an alkylene group, or an epoxy group is bonded directly to a saturated carbon ring, or the like. These epoxy compounds may be used alone or in combination of two or more. Among them, alicyclic epoxy compounds are preferably used since they have excellent cationic polymerizability.

The glycidyl ether compound of an aromatic compound or a chain compound having a hydroxyl group can be produced, for example, by a method of subjecting an aromatic compound or a chain compound to the addition condensation of epichlorohydrin under basic conditions. Such glycidyl ether compounds of an aromatic compound or a chain compound having a hydroxyl group include diglycidyl ether of a bisphenol, polyaromatic epoxy resin, diglycidyl ether of an alkylene glycol or polyalkylene glycol, and the like do.

Examples of the diglycidyl ether of bisphenol include glycidyl ether compounds of bisphenol A and oligomeric compounds thereof, glycidyl ether compounds of bisphenol F and oligomeric compounds thereof, 3,3 ', 5,5'-tetramethyl Glycidyl ether compounds of 4,4'-biphenol and oligomeric forms thereof.

As the multi-directional cyclic epoxy resin, there may be mentioned, for example, glycidyl ether compounds of phenol novolac resins, glycidyl ether compounds of cresol novolak resins, glycidyl ether compounds of phenol aralkyl resins, glycidyl Etherified glycidyl ether, and glycidyl etherified glycidyl ether of phenol dicyclopentadiene resin. The glycidyl ether compounds of trisphenols and their oligomeric forms also belong to the polyaromatic cyclic epoxy resin.

As diglycidyl ether of alkylene glycol or polyalkylene glycol, for example, glycidyl ether of ethylene glycol, glycidyl ether of diethylene glycol, glycidyl ether of 1,4-butanediol, 1 , Glycidyl ether of 6-hexanediol, and the like.

The glycidyl amino group of the compound having an amino group can be produced, for example, by a method of subjecting an amino group of the above compound to an addition condensation of epichlorohydrin under basic conditions. The compound having an amino group may have a hydroxyl group at the same time. Glycidyl aminoglycosides of 1,3-phenylenediamine and their oligomeric forms, glycidyl amino acids of 1,4-phenylenediamine and their oligomeric forms, 3 -Glycidylamination of aminophenols and glycidyl etherates and their oligomeric forms, glycidylamination of 4-aminophenols and glycidyl etherates and oligomeric forms thereof, and the like.

The epoxide of a chain compound having a C-C double bond can be prepared by a method of epoxidizing a C-C double bond of the chain compound with a peroxide under basic conditions. The chain compound having C-C double bonds includes butadiene, polybutadiene, isoprene, pentadiene, hexadiene, and the like. Further, terpenes having a double bond can also be used as epoxidation raw materials, and as the acyclic monoterpene, linalol and the like can be used. The peroxide used for the epoxidation may be, for example, hydrogen peroxide, peracetic acid, tert-butyl hydroperoxide and the like.

The alicyclic epoxy compound in which the glycidyloxy group or the epoxy group is bonded to the saturated carbon ring directly or via alkylene is a hydrogenated polyphenylene group obtained by hydrogenating an aromatic ring of an aromatic compound having a hydroxyl group represented by the above- A glycidyl ether compound of a hydroxy compound, a glycidyl ether compound of a cycloalkane compound having a hydroxyl group, and an epoxy compound of a cycloalkane compound having a vinyl group.

The epoxy compounds described above can be easily obtained from commercial products. Examples thereof include "jER" series sold by Mitsubishi Chemical Corporation under the trade name of "Epiclon" sold by DIC Corporation, "ADOTOR (registered trademark)" available from ADEKA, "ADEKA RESIN (registered trademark)" available from Kabushiki Kaisha, "Denacor (registered trademark) available from Nagase Chemtex Co., "Dow Epoxy" sold by Dow Chemical Company, and "Tepic (registered trademark)" sold by Nissan Kagaku Kogyo Co., Ltd., and the like.

On the other hand, an alicyclic epoxy compound to which an epoxy group is directly bonded to a saturated carbon ring can be obtained by, for example, a method of epoxidizing a CC double bond of a nonaromatic cyclic compound having a CC double bond in a ring using a peroxide under basic conditions Can be manufactured. Examples of the non-aromatic cyclic compound having a CC double bond in the ring include a compound having a cyclopentane ring, a compound having a cyclohexane ring, a cyclopentane ring, or a cyclohexane ring in which at least two carbon atoms are further bonded to form an additional ring And a polycyclic compound formed thereon. The non-aromatic cyclic compound having a C-C double bond in the ring may have a separate C-C double bond outside the ring. Examples of the non-aromatic cyclic compound having a C-C double bond in the ring include cyclohexene, 4-vinylcyclohexene, monocyclic monoterpene limonene, and? -Pinene.

The alicyclic epoxy compound to which the epoxy group is directly bonded to the saturated carbon ring may be a compound in which at least two alicyclic structures having an epoxy group directly bonded to the ring as described above are formed in the molecule through a suitable linking group. Examples of the linking group include an ester bond, an ether bond, an alkylene bond, and the like.

Specific examples of the alicyclic epoxy compound to which the epoxy group is directly bonded to the saturated carbon ring include the following.

3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-

1,2-epoxy-4-vinylcyclohexane,

1,2-epoxy-4-epoxyethylcyclohexane,

1,2-epoxy-1-methyl-4- (1-methyl epoxyethyl) cyclohexane,

3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylmethyl

Adducts of 2,2-bis (hydroxymethyl) -1-butanol with 4-epoxyethyl-1,2-epoxycyclohexane,

Ethylene bis (3,4-epoxycyclohexanecarboxylate),

Oxydiethylene bis (3,4-epoxycyclohexanecarboxylate),

1,4-cyclohexanedimethylbis (3,4-epoxycyclohexanecarboxylate), 1,4-

3- (3,4-epoxycyclohexylmethoxycarbonyl) propyl 3,4-epoxycyclohexanecarboxylate and the like.

The alicyclic epoxy compounds to which the epoxy group is bonded directly to the above-mentioned saturated carbon ring are also available commercially. For example, " seroxite " series and " cyclomer ", both of which are sold under the trade names of Dai- , &Quot; SIRACURE UVR " series sold by Dow Chemical Company, and the like.

The curable adhesive containing an epoxy compound may further contain an active energy ray-curable compound other than an epoxy compound. Examples of the active energy ray-curable compound other than the epoxy compound include an oxetane compound and an acrylic compound. Among them, there is a possibility of accelerating the curing rate in the cationic polymerization, so it is preferable to use an oxetane compound in combination.

The oxetane compound is a compound having a 4-membered ring ether in the molecule, and examples thereof include the following.

1,4-bis [(3-ethyloxetan-3-yl) methoxymethyl] benzene,

3-ethyl-3- (2-ethylhexyloxymethyl) oxetane,

Bis (3-ethyl-3-oxetanylmethyl) ether,

3-ethyl-3- (phenoxymethyl) oxetane,

3-ethyl-3- (cyclohexyloxymethyl) oxetane,

Phenol novolak oxetane,

Xylylene bisoxetane,

1,3-bis [(3-ethyloxetan-3-yl) methoxy] benzene and the like.

Commercially available oxetane compounds are also readily available. For example, "Aronoxetane (registered trademark)" series sold by Toagosei Co., Ltd., "ETERNACOLL (registered trademark)" sold by Ube Gosan Co., Registered trademark &quot; series).

The curable compound containing an epoxy compound or an oxetane compound is preferably one which is not diluted with an organic solvent or the like in order to make the adhesive to which the epoxy compound or oxetane compound is blended as a solvent. As other components constituting the adhesive, it is preferable to use only a small amount of components including a cation polymerization initiator and a sensitizer described below, or a powder or liquid of the compound in which the organic solvent is removed and dried more than the one dissolved in the organic solvent .

The cationic polymerization initiator is a compound which generates cationic species upon irradiation with an active energy ray, for example, ultraviolet rays. As long as it gives the adhesive strength and the curing rate required for the adhesive to which it is compounded, for example, an aromatic diazonium salt; Onium salts such as aromatic iodonium salts and aromatic sulfonium salts; Iron-arene complexes and the like. These cationic polymerization initiators may be used alone or in combination of two or more.

Examples of the aromatic diazonium salt include the following.

Benzene diazonium hexafluoroantimonate, benzene diazonium hexafluoroantimonate,

Benzene diazonium hexafluorophosphate,

Benzene diazonium hexafluoroborate and the like.

Examples of the aromatic iodonium salt include the following.

Diphenyl iodonium tetrakis (pentafluorophenyl) borate,

Diphenyl iodonium hexafluorophosphate,

Diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate,

Bis (4-nonylphenyl) iodonium hexafluorophosphate and the like.

Examples of the aromatic sulfonium salts include the following.

Triphenylsulfonium hexafluorophosphate,

Triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate,

Triphenylsulfonium tetrakis (pentafluorophenyl) borate,

Diphenyl (4-phenylthiophenyl) sulfonium hexafluoroantimonate,

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

4,4'-bis [di (? - hydroxyethoxyphenyl) sulfonio] diphenylsulfide bis hexafluoroantimonate,

4,4'-bis [di (beta -hydroxyethoxyphenyl) sulfonio] diphenylsulfide bis hexafluorophosphate,

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

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

4-phenylcarbonyl-4'-diphenylsulfoniumiodiphenylsulfide hexafluorophosphate,

4- (p-tert-butylphenylcarbonyl) -4'-diphenylsulfoniodiphenylsulfide hexafluoroantimonate,

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

Examples of the iron-arene complexes include the following.

Xylene-cyclopentadienyl iron (II) hexafluoroantimonate,

Cumene-cyclopentadienyl iron (II) hexafluorophosphate,

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

Among the cationic polymerization initiators, aromatic sulfonium salts are preferably used because they have an ultraviolet ray absorption property even in a wavelength range of 300 nm or more, and are therefore excellent in curability and can be provided with an adhesive layer having good mechanical strength and adhesive strength.

Commercially available cationic polymerization initiator systems can be easily obtained. Examples thereof include " Kayarad (registered trademark) " series sold by Nippon Kayaku Co., Ltd., " UVI "series, a photo acid generator" CPI "series sold by Sanwa Pro Co., Ltd., photo acid generators" TAZ "," BBI "and" DTS "sold by Midori Kagaku Co., "ADEKA OPTOMA" series sold by ADEKA Corporation, "RHODORSIL (registered trademark)" sold by ROADIASA, and the like.

In the active energy ray curable adhesive, the cationic polymerization initiator is blended in a proportion of usually 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass, based on 100 parts by mass of the total amount of the active energy ray curable adhesive. If the amount is too small, the curing becomes insufficient, which may lower the mechanical strength and the adhesive strength of the adhesive layer. If the amount is too large, the amount of ionic substances in the adhesive layer increases to increase the hygroscopicity of the adhesive layer, which may deteriorate the durability of the resulting polarizing plate.

When the active energy ray-curable adhesive is used in an electron beam curing type, it is not particularly necessary to contain a photopolymerization initiator in the composition, but when it is used in an ultraviolet curing type, a photo radical generator is preferably used. Examples of the photo-radical generator include a hydrogen-extracted photo-radical generator and a cleaved photo-radical generator.

Examples of the hydrogen-extracted photocatalyst include 1-methylnaphthalene, 2-methylnaphthalene, 1-fluoronaphthalene, 1-chloronaphthalene, 2-chloronaphthalene, 1-bromonaphthalene, Naphthalene derivatives such as iodonaphthalene, 2-iodonaphthalene, 1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene and 1,4-dicyanonaphthalene, anthracene, 1,2- , 9,10-dichloroanthracene, 9,10-dibromoanthracene, 9,10-diphenylanthracene, 9-cyananoanthracene, 9,10-dicyanoanthracene, 2,6,9,10- Anthracene derivatives such as anthracene, pyrene derivatives, carbazole, 9-methylcarbazole, 9-phenylcarbazole, 9-prop-2-ynyl-9H-carbazole, 9-methyl-3-nitro-9H-carbazole, 9-methyl-3,6-dinitro-9H-carbazole, 9-octanoylcarbazole, 9- Carbazole methanol, Carbazole, 9-carbazole propionic acid, 9-carbazole propionitrile, 9-ethyl-3,6-dinitro-9H-carbazole, Carbazol, 9- (ethoxycarbonylmethyl) carbazole, 9- (morpholinomethyl) carbazole, 9-acetylcarbazole, 9-allylcarbazole, Carbazole, 9- (4-methoxyphenyl) carbazole, 9- (1-ethoxy-2-methyl- Carbazole, 3,6-dinitro-9H-carbazole, 3,6-diphenyl-9H-carbazole, 2-hydroxycarbazole, 3,6-diacetyl- Carbazole, carbazole derivatives such as benzophenone, 4-phenylbenzophenone, 4,4'-bis (dimethoxy) benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis Diethylamino) benzophenone, 2-benzoylbenzoic acid methyl ester, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 3,3'- Benzophenone derivatives such as dimethyl-4-methoxybenzophenone and 2,4,6-trimethylbenzophenone, aromatic carbonyl compounds, [4- (4-methylphenylthio) phenyl] -phenylmethanone, xanthone, But are not limited to, thioxanthone, thioxanthone, 2-chlorothioxanthone, 4-chlorothioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, , 1-chloro-4-propoxytitanium oxide and the like, coumarin derivatives, and the like.

The heat-generating type photo-radical generating agent is a photo-radical generating agent of the type in which the compound is cleaved to generate radicals upon irradiation with an active energy ray. Specific examples thereof include arylalkylketones such as benzoin ether derivatives, acetophenone derivatives, Oxime ketones, acylphosphine oxides, thiobenzoic acid S-phenyls, titanocenes, and derivatives obtained by high-molecular weight compounds of these, but the present invention is not limited thereto. Examples of commercially available reversible photo radical generators include 1- (4-dodecylbenzoyl) -1-hydroxy-1-methylethane, 1- (4-isopropylbenzoyl) -1- 1-hydroxy-1-methylethane, 1- [4- (2-hydroxyethoxy) Benzoyl] -1-hydroxy-1-methylethane, diphenyl ketone, phenyl-1-hydroxy-cyclohexyl ketone, benzyl dimethyl ketal, bis (cyclopentadienyl) (Η6-isopropylbenzene) - (η5-cyclopentadienyl) -iron (II) hexafluorophosphate, trimethylbenzoyldiphenylphosphine oxide, bis 2,6-dimethoxy-benzoyl) - (2,4,4-trimethyl-pentyl) -phosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-dipentoxyphenylphosphine oxide or bis (2,4,6-trimethylbenzoyl) phenyl-phosphine oxide, (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminop Plate, 4, and the like (methylthio-benzoyl) -1-methyl-1-morpholino-ethane, but it is not limited thereto.

Among the active energy-curable adhesives used in the present invention, the photo-radical generating agents included in the electron beam-curable type, that is, the hydrogen extraction type or can-opened type photo radical generating agents can be used singly, However, from the viewpoints of the stability and curability of the photo-radical generating agent monolith, more preferred is a combination of at least one type of photo-initiable photo-radical generating agent. Among them, acylphosphine oxides are preferable, and more specifically trimethylbenzoyldiphenylphosphine oxide (trade name "DAROCURE TPO"; available from Chiba Japan Co.), bis (2,6-dimethoxy (2,4,6-trimethylbenzoyl) -2,4-benzoyl) - (2,4,4-trimethyl-pentyl) -phosphine oxide (trade name: CGI 403, manufactured by Chiba Japan) -Diphenoxyphenylphosphine oxide (trade name &quot; Irgacure 819 &quot;; available from Chiba Japan Co., Ltd.) is preferable.

The active energy ray-curable adhesive may contain a sensitizer if necessary. By using a sensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the adhesive layer can be further improved. As the sensitizer, the above-mentioned one can be appropriately applied.

When the sensitizer is blended, it is preferable that the compounding amount is in the range of 0.1 to 20 parts by mass based on 100 parts by mass of the total amount of the active energy ray-curable adhesive.

Various kinds of additives may be added to the active energy ray-curable adhesive within a range that does not adversely affect the effect. Examples of additives that can be blended include ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoaming agents and the like.

Each of these components constituting the active energy ray-curable adhesive is usually used in a state dissolved in a solvent. When the active energy ray-curable adhesive contains a solvent, an adhesive layer can be obtained by applying an active energy ray-curable adhesive to the applied surface and drying the applied adhesive. The components that are not dissolved in the solvent may be dispersed in the system.

The active energy ray curable adhesive is applied on the adhesion surface of the first retardation layer 1 with the second retardation layer 2 or on the adhesion surface of the second retardation layer 2 with the first retardation layer 1, . The surface of the first retardation layer 1 to be adhered to the second retardation layer 2 and the surface of the second retardation layer 2 to be adhered to the first retardation layer 1 are subjected to a corona treatment, Or the like, or a primer layer or the like may be formed. The thickness of the primer layer is usually about 0.001 to 5 mu m, preferably 0.01 mu m or more, more preferably 4 mu m or less, and furthermore preferably 3 mu m or less. If the primer layer is excessively thick, the appearance of the composite retardation plate 5 is likely to be defective.

The viscosity of the active energy ray-curable adhesive is not particularly limited as long as it has a viscosity capable of being coated by various methods. The viscosity at 25 ° C is preferably in the range of 10 to 1,000 mPa · sec, more preferably in the range of 20 to 500 mPa · sec. &lt; / RTI &gt; If the viscosity is too small, it tends to be difficult to form a layer with a desired thickness. On the other hand, if the viscosity is too large, it becomes difficult to flow, and it tends to be difficult to obtain a homogeneous coating film free from unevenness. The viscosity referred to herein is a value measured at 10 rpm after the temperature of the adhesive is adjusted to 25 캜 by using an E-type viscometer.

The active energy ray-curable adhesive can be used as an electron beam hardening type or an ultraviolet ray hardening type. In this specification, an active energy ray is defined as an energy ray capable of decomposing a compound generating an active species to generate an active species. Examples of such active energy rays include visible light, ultraviolet ray, infrared ray, X-ray, alpha ray, beta ray, gamma ray and electron ray.

In the electron beam hardening type, the irradiation condition of the electron beam may be any suitable condition as far as it is capable of curing the active energy ray hardening type adhesive. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the accelerating voltage is less than 5 kV, the electron beam may not reach the adhesive, resulting in insufficient curing. If the accelerating voltage exceeds 300 kV, the penetrating power passing through the sample is too strong and the electron beam is rebounded to damage the transparent protective film or polarizer There is a fear that it may be applied. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the adhesive becomes insufficient in curing. When the irradiation dose exceeds 100 kGy, the retardation plate is damaged, resulting in a decrease in mechanical strength or yellowing, and desired optical characteristics can not be obtained.

The irradiation with the electron beam is usually carried out in an inert gas atmosphere, but may be carried out under a condition where air or oxygen is slightly introduced, if necessary. By appropriately introducing oxygen, oxygen is first inhibited by contacting with the surface of the retarder plate where the electron beam abuts, thereby preventing damage to the retarder, and it is possible to efficiently irradiate the electron beam only to the adhesive.

In the ultraviolet curing type, the light irradiation intensity of the active energy ray-curable adhesive is determined depending on the composition of the adhesive, and is not particularly limited, but is preferably 10 to 1,000 mW / cm2. If the light irradiation intensity to the resin composition is less than 10 mW / cm 2, the reaction time becomes long, and if it exceeds 1,000 mW / cm 2, the heat radiated from the light source and the heat generated during polymerization of the composition may cause yellowing . The irradiation intensity is preferably the intensity in the wavelength range effective for activation of the photocationic polymerization initiator, more preferably the intensity in the wavelength range of 400 nm or less, more preferably the wavelength is 280 to 320 nm &lt; / RTI &gt; It is preferable that the amount of the accumulated light is set to be not less than 10 mJ / cm 2, preferably 100 to 1,000 mJ / cm 2, once or plural times with such light irradiation intensity. If the amount of accumulated light in the adhesive is less than 10 mJ / cm 2, the generation of active species derived from the polymerization initiator is not sufficient and the curing of the adhesive becomes insufficient. On the other hand, if the accumulated light quantity exceeds 1,000 mJ / cm 2, the irradiation time becomes very long, which is disadvantageous for the productivity improvement. At this time, depending on the type of the film of the retardation film to be used and the combination of the adhesive species, it depends on the wavelength range (UVA (320 to 390 nm), UVB (280 to 320 nm), etc.)

The light source used for polymerizing and curing the adhesive by irradiation of the active energy ray in the present invention is not particularly limited and examples thereof include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a xenon lamp, A tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting light in a wavelength range of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave excited mercury lamp, and a metal halide lamp. From the viewpoint of energy stability and simplicity of the device, it is preferable that the ultraviolet light source has a light emission distribution at a wavelength of 400 nm or less.

[Optical laminate]

In the optical laminate of the present invention, the polarizing plate and the above-described composite retarder are laminated. The optical laminate may include a second adhesive layer for bonding the polarizing plate and the compound retarder. It is possible to obtain an optical laminate having antireflection performance by adjusting the layer configuration of the compound retarder laminated on the polarizing plate. The optical laminate having antireflection performance is, for example, a circular polarizer. By providing an optical laminate having antireflection performance on the viewer side of the image display panel in the image display apparatus, deterioration in visibility due to reflection of foreign light can be suppressed.

As the layer structure of the optical laminate composed of the polarizing plate and the compound retarder capable of suppressing deterioration of visibility due to reflection of foreign light,

v) an optical laminate having a layer structure in which a polarizing plate, a 1/2 wavelength layer (first retardation layer), a second adhesive layer, and a 1/4 wavelength layer (second retardation layer)

(vi) an optical laminate having a layer structure in which a polarizing plate, a 1/4 wavelength layer (first retardation layer), a second adhesive layer, and an optical compensation layer (second retardation layer), such as a positive C plate, sieve

Are specifically exemplified.

The thickness of the optical laminate is usually 50 to 500 占 퐉, preferably 50 to 200 占 퐉, and more preferably 50 to 150 占 퐉, from the viewpoint of thinning.

<Polarizer>

The polarizing plate may be a film having a polarizing function for obtaining linearly polarized light from transmitted light. Examples of the film include a stretched film on which a dye having absorption anisotropy is adsorbed, a film on which a dye coated with a dye having absorption anisotropy is applied as a polarizer, and the like. Examples of the dye having absorption anisotropy include a dichroic dye. As the film coated with the pigment having absorption anisotropy, which is used as a polarizer, a film comprising a dichroic dye having a liquid crystalline property or a film containing a dichroic dye and a polymerizable liquid crystal A film having a liquid phase layer obtained by applying a composition, and the like.

(A polarizing plate having a stretched film as a polarizer)

A polarizing plate provided with a stretched film as a polarizer on which a dye having absorption anisotropy is adsorbed will be described. The stretched film, which is a polarizer and has absorption of an absorption anisotropy, is produced by a process of uniaxially stretching a polyvinyl alcohol based resin film, a step of adsorbing the dichroic dye by staining the polyvinyl alcohol based resin film with a dichroic dye, A step of treating the polyvinyl alcohol resin film adsorbed with a dichroic dye with an aqueous solution of boric acid, and a step of washing with water after treatment with an aqueous solution of boric acid. Such a polarizer may be used as the polarizing plate as it is, or a transparent protective film may be bonded to at least one surface of the polarizing plate as a polarizing plate.

The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate resin, a copolymer of vinyl acetate and another monomer copolymerizable therewith is used in addition to polyvinyl acetate which is a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehyde may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably 1,500 to 5,000.

Such a polyvinyl alcohol-based resin film is used as a raw film of a polarizing plate. The method of forming the polyvinyl alcohol-based resin is not particularly limited, and a film can be formed by a known method. The film thickness of the polyvinyl alcohol based textile film may be, for example, about 10 to 150 mu m.

The uniaxial stretching of the polyvinyl alcohol based resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. It is also possible to perform uniaxial stretching in these plural steps. In uniaxial stretching, the film may be uniaxially stretched between rolls having different circumferential velocities, or uniaxially stretched using hot rolls. The uniaxial stretching may be either dry stretching in which stretching is performed in the atmosphere or wet stretching in which stretching is performed in a state in which a polyvinyl alcohol based resin film is swollen with a solvent. The stretching magnification is usually about 3 to 8 times.

The dyeing by the dichroic dye of the polyvinyl alcohol-based resin film is performed by, for example, a method of immersing the polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye. Specific examples of the dichroic dye include iodine and dichroic organic dyes. The dichroic organic dyes include C.I. DIRECT RED 39, and dichromatic direct dyes composed of compounds such as trisazo and tetrakisazo. The polyvinyl alcohol-based resin film is preferably subjected to immersion treatment in water before the dyeing treatment.

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

On the other hand, when a dichroic organic dye is used as the dichroic dye, a method in which a polyvinyl alcohol-based resin film is dipped in an aqueous solution containing a water-soluble dichroic dye is generally employed. The content of the dichroic organic dye in the aqueous solution is usually about 1 x 10 ^-4 to 10 mass parts, preferably 1 x 10 ^{-3 to} 1 mass part, per 100 mass parts of water, more preferably 1 x 10 ^{-3 to} 1 10 ^-2 parts by mass. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80 캜. The immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing with the dichroic dye can be carried out by dipping the dyed polyvinyl alcohol resin film in an aqueous boric acid solution. The content of boric acid in the aqueous solution of boric acid is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the dichroic dye, it is preferable that the aqueous solution of boric acid contains potassium iodide. In this case, the content of potassium iodide is usually about 0.1 to 15 mass parts per 100 mass parts of water, 12 parts by mass. The immersing time in the aqueous solution of boric acid is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid treatment is usually 50 占 폚 or higher, preferably 50 to 85 占 폚, and more preferably 60 to 80 占 폚.

The polyvinyl alcohol resin film after boric acid treatment is usually subjected to water washing treatment. The water washing treatment can be carried out, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually about 5 to 40 캜. The immersion time is usually about 1 to 120 seconds.

After washing with water, a drying treatment is carried out to obtain a polarizer. The drying treatment can be carried out, for example, using a hot-air dryer or a far-infrared heater. The drying treatment temperature is usually about 30 to 100 占 폚, preferably 50 to 80 占 폚. The drying treatment time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. By the drying treatment, the water content of the polarizer is reduced to a practically acceptable level. The water content thereof is usually about 5 to 20 mass%, preferably 8 to 15 mass%. If the moisture content is less than 5 mass%, the flexibility of the polarizer is lost, and the polarizer may be damaged or broken after drying. If the moisture content exceeds 20 mass%, the thermal stability of the polarizer may deteriorate.

The thickness of the polarizer obtained by uniaxially stretching, dying with a dichroic dye, treating with boric acid, washing with water and drying is preferably 5 to 40 占 퐉 in the polyvinyl alcohol type resin film.

The material of the protective film to be bonded to one surface or both surfaces of the polarizer is not particularly limited and examples thereof include a cyclic polyolefin resin film, acetic acid cellulose resin film made of a resin such as triacetylcellulose and diacetylcellulose, polyethylene terephthalate, (Meth) acrylic resin film, and polypropylene-based resin film, which are known in the art, such as a polyester-based resin film made of a resin such as polyethylene naphthalate or polybutylene terephthalate, a polycarbonate-based resin film, . The thickness of the protective film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and usually 5 μm or more and 20 μm or more from the viewpoint of thinning. The protective film on the viewer side may or may not have a retardation. On the other hand, the protective film on the side laminated on the first retardation layer preferably has a retardation of 10 nm or less.

(A polarizing plate having a film having a liquid crystal layer as a polarizer)

A polarizing plate having a film having a liquid crystal layer as a polarizer will be described. Examples of the film coated with a pigment having absorption anisotropy, which is used as a polarizer, include a composition containing a dichroic dye having liquid crystallinity or a film obtained by applying a composition containing a dichroic dye and a liquid crystal compound. The film may be used alone as a polarizing plate, or may be used as a polarizing plate in a structure having a protective film on one side or both sides thereof. The protective film may be the same as the polarizing plate having the above stretched film as a polarizer.

Thin film is preferable for a film coated with a dye having absorption anisotropy, but if it is too thin, the strength tends to be lowered and workability tends to be poor. The thickness of the film is usually 20 占 퐉 or less, preferably 5 占 퐉 or less, more preferably 0.5 占 퐉 or more and 3 占 퐉 or less.

As the film coated with the dye having an absorption anisotropy, specifically, a film described in Japanese Patent Application Laid-Open Publication No. 2012-33249 may be mentioned.

The dye having the absorption anisotropy may be directly applied to the first retardation layer side of the composite retardation plate to obtain an optical laminate in which the composite retardation plate and the polarizing plate are laminated. In this case, the composite retardation plate and the polarizing plate can be laminated without the second adhesive layer.

&Lt; Second adhesive layer >

The second adhesive layer may be composed of, for example, a pressure-sensitive adhesive, an aqueous adhesive, an active energy ray-curable adhesive, or a combination thereof. Among these, the second adhesive layer is a cured layer of the active energy ray-curable adhesive, so that even when the optical laminate including the composite retardation layer of the present invention is bent, occurrence of wrinkles at the curved portion can be further suppressed desirable. In this specification, the term &quot; second adhesive layer &quot; includes not only an adhesive layer composed of an adhesive but also an adhesive layer composed of a pressure sensitive adhesive.

The description of the first adhesive layer is applied to a pressure-sensitive adhesive, an aqueous adhesive, and an active energy ray-curable adhesive constituting the second adhesive layer. The first adhesive layer and the second adhesive layer may be formed of the same material or different materials.

[Composite retardation plate and manufacturing method of optical laminate]

The composite retardation film of the present invention is a composite retardation film comprising a first retardation layer 13 including a first retardation layer 13, a first orientation layer 12 and a first base layer 11 as shown in Fig. 3 (A) 10 and a second retardation layer 20 including a second retardation layer 23, a second alignment layer 22 and a first base layer 21 as shown in Fig. 3 (B) 1 adhesive layer 40, as shown in Fig. The compound phase difference plate of the present invention is characterized in that the first retardation layer 13, the first alignment layer 12, the first base layer 11, the first adhesive layer 40, the second base layer 21, The second orientation layer 22 and the second phase difference-generating layer 23 may be laminated in this order.

As a method of bonding the first retardation layer 10 and the second retardation layer 20, there is a method of coating the first retardation layer 10 or the second retardation layer 20 on one or both of the bonding surfaces of the first retardation layer 10 and the second retardation layer 20 And another bonding surface is laminated thereon to cure the adhesive constituting the first adhesive layer.

For coating the adhesive constituting the first adhesive layer, various coating methods such as doctor blade, wire bar, die coater, comma coater, and gravure coater can be used.

As a method of curing the adhesive constituting the first adhesive layer, a method of curing according to the type of adhesive may be appropriately selected. When the adhesive is an active energy ray-curable adhesive, a method of curing with an active energy ray as described above is preferred. A corona treatment, a plasma treatment, or the like may be performed on either the bonding surface of the first retardation layer 10 or the bonding surface of the second retardation layer 20, or a primer layer may be formed.

The composite phase difference layer of the present invention may be a laminate as shown in Fig. 3 (C), or may be a laminate in which at least one layer of the first base layer 11 and the second base layer 21 is peeled off . Further, a laminate in which the first base layer 11 and the first alignment layer 12 are peeled off from the laminate shown in Fig. 3 (C) may be used, and the laminate shown in Fig. 3 (C) The layer 21 and the second alignment layer 22 may be peeled off.

[Use of optical laminate]

The optical laminate as the circularly polarizing plate is an optical laminate disposed on the viewer side of the image display panel and giving antireflection performance, and can be used for various image display devices. An image display device is an apparatus having an image display panel and includes a light emitting element or a light emitting device as a light emitting source. Examples of the image display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (e.g., (E.g., a surface field emission display (SED)), an electronic paper (a display device using electronic ink or an electrophoretic device, a plasma display device, a projection display device (e.g., a grating light valve (GLV) display device, a digital micromirror device And a piezoelectric ceramic display. The liquid crystal display device may be any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflection type liquid crystal display device, a direct viewing type liquid crystal display device, a projection type liquid crystal display device, These image display devices may be an image display device for displaying a two-dimensional image, a stereoscopic image for displaying a three- In particular, the optical laminate as a circularly polarizing plate can be effectively used in an organic electroluminescence (EL) display device capable of having an image display panel having a bent portion.

According to the present invention, even if the optical laminate is bent and arranged so as to follow it on the surface of the image display panel having the bent portion, an optical laminate without wrinkles can be obtained.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples.

[Production example of retardation layer]

(1) Preparation of composition for liquid crystal retardation formation

80 parts of the polymerizable liquid crystal compound (A1), 20 parts of the polymerizable compound (A2), 6 parts of the polymerization initiator, 0.1 part of the leveling agent and 400 parts of cyclopentanone, and stirring the resulting mixture at 80 캜 for 1 hour, (1) was obtained.

Hereinafter, used polymerizable compound A1, polymerizable compound A2, polymerization initiator and leveling agent are shown. The polymerizable liquid crystal compound A1 and the polymerizable liquid crystal compound A2 were synthesized by the method described in JP-A-2010-31223.

Polymerizable compound A1:

Polymerizable compound A2:

Polymerization initiator: 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; available from Ciba Specialty Chemicals)

Leveling agent (0.1 part): Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie).

(2) Preparation of composition for forming orientation layer

(2-1) Preparation of composition (1) for forming orientation layer

5 parts of the following compounds and 95 parts of cyclopentanone were mixed and the resulting mixture was stirred at 80 占 폚 for 1 hour to obtain a composition (1) for forming an orientation layer.

Photo-orientable material (5 parts):

(2-2) Preparation of alignment layer-forming composition (2)

2-butoxyethanol was added to SANEBA SE-610 (manufactured by Nissan Kagaku Kogyo K.K.), which is an orienting polymer, to obtain an orientation layer forming composition (2). The solid content in the alignment layer-forming composition (2) was 1%.

(3) Production example of retardation layer

(3-1) Production Example of Phase Separation Layer (1) (Production Example of Inverted-Dispersed 1/4 Wavelength Layer)

The surface of the polyethylene terephthalate (PET) film was treated once with a corona treatment apparatus (AGF-B10, manufactured by Gas Chemical Company) under conditions of output of 0.3 kW and treatment rate of 3 m / min. (1) was applied onto the surface subjected to the corona treatment by a bar coater, followed by drying at 80 DEG C for 1 minute, and then using a polarizing UV irradiator (SPOT CURE SP-7, manufactured by Ushio Denki Kabushiki Kaisha) And subjected to polarized UV exposure at an integrated light quantity of 100 mJ / cm 2. The film thickness of the obtained alignment layer was measured with a laser microscope (LEXT, manufactured by Olympus, Inc.), and found to be 100 nm. Subsequently, the liquid crystal phase difference-forming composition (1) was coated on the alignment layer using a bar coater and dried at 120 DEG C for 1 minute. Thereafter, a high-pressure mercury lamp (UniCure VB-15201BY-A, manufactured by Ushio Denki Kabushiki Kaisha) (Having a wavelength of 365 nm and an integrated amount of light at a wavelength of 365 nm: 1000 mJ / cm &lt; 2 &gt; in an atmosphere of nitrogen) to obtain a phase difference layer Layer). The retardation value of the obtained retardation layer was measured, and Re (550) = 138 nm and Rth (550) = 72 nm. Further, the retardation values at a wavelength of 450 nm and a wavelength of 650 nm were measured. Re (450) = 121 nm and Re (650) = 141 nm. The relationship of in-plane retardation values at each wavelength was as follows. Further, the retardation value of the polyethylene terephthalate film is not included.

Re (450) / Re (550) = 0.87

Re (650) / Re (550) = 1.02

(3-2) Production example of retardation layer (2) (Production example of positive C layer)

The surface of the cycloolefin polymer (COP) film was treated once with a corona treatment apparatus under the conditions of an output of 0.3 kW and a treatment rate of 3 m / min. On the surface subjected to the corona treatment, the composition (2) for forming an orientation layer was applied using a bar coater and dried at 90 DEG C for 1 minute to obtain an orientation film. The film thickness of the obtained alignment layer was measured by a laser microscope and found to be 34 nm. Subsequently, the liquid crystal phase difference-forming composition (1) was coated on the alignment layer using a bar coater and dried at 90 DEG C for 1 minute. Then, ultraviolet light was irradiated (at a wavelength of 365 nm : 1000 mJ / cm &lt; 2 &gt;) to obtain a retardation layer (positive C layer) having a liquid crystal layer as a phase difference developing layer. The film thickness of the resulting retardation layer was measured by a laser microscope and found to be 450 nm. The retardation value of the obtained retardation layer 2 at a wavelength of 550 nm was measured. Re (550) = 1 nm and Rth (550) = -70 nm. Further, the retardation value of the cycloolefin polymer film is not included.

[Production example of photocurable adhesive 1 to 11]

(1) Preparation of cation-curable component

The following cationic curable components were prepared.

(A-1) 3 ', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Chemical Industries, Ltd.)

(A-2) 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct (trade name: EHPE3150, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) of 2,2-bis (hydroxymethyl) ,

(B-1) neopentyl glycol diglycidyl ether (trade name: EX-211, manufactured by Nagase ChemteX Corporation)

(B-2) 1,4-butanediol diglycidyl ether (trade name: EX-214, manufactured by Nagase Chemtex Co., Ltd.)

(B-3) 2-ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation)

(C-1) Resorcinol diglycidyl ether (trade name: EX-201, manufactured by Nagase ChemteX Corporation)

(C-2) polyfunctional glycidyl ether (trade name: VG3101L, manufactured by Purintech)

(Trade name: OXT-221, manufactured by Toagosei Co., Ltd.) (D-1) 3-Ethyl-3 - [(3-ethyloxetan-

(D-2) xylylene bisoxetane (trade name: OXT-121, manufactured by Toagosei Co., Ltd.)

(2) Preparation of Radical Curable Component

A radical-curable component shown below was prepared.

(E-1) 4-hydroxybutyl acrylate (trade name: 4HBA, manufactured by Nippon Gasee Chemical Industry Co., Ltd.)

(E-2) 1,4-cyclohexanedimethanol monoacrylate (trade name: CHDMMA, manufactured by Nippon Gosei Co., Ltd.)

(E-3) Dimethylacrylamide (trade name: DMAA, manufactured by Kohjin Chemical Co., Ltd.)

(E-4) polyurethane acrylate (trade name: Shikou UV-3000B, manufactured by Nippon Gohsei Kagaku Kogyo K.K.)

(3) a cationic polymerization initiator and a radical polymerization initiator

The following cationic polymerization initiator and radical polymerization initiator (abbreviated as &quot; initiator &quot; in Table 1) were prepared.

(F-1) cationic polymerization initiator (trade name: CPI-100, manufactured by San A Pro Co.)

(F-2) Radical polymerization initiator (trade name: IRGACURE1173, manufactured by BASF)

(4) Preparation of sensitizer

The following sensitizer was prepared.

(G-1) 1,4-diethoxynaphthalene (abbreviated as "DEN" in Table 1)

(5) Preparation of adhesives 1 to 11

The cationic curing component and the cationic polymerization initiator or the radical curable component and the radical polymerization initiator were mixed at the compounding ratios shown in Table 1 (unit: parts) and defoamed to prepare the photocurable adhesives 1 to 11. In addition, the cationic polymerization initiator (F-1) was compounded as a 50% propylene carbonate solution, and Table 1 shows the solid content thereof.

[Preparation of pressure-sensitive adhesive 1]

(1) Preparation of materials

Acrylic base polymer (G-1), isocyanate crosslinking agent (G-2) and silane coupling agent (G-3) shown below were prepared.

(H-1) a copolymer of butyl acrylate, methyl acrylate, acrylic acid and hydroxyethyl acrylate

(Solid content concentration: 75%) ("Colonate L" (trade name), manufactured by TOSOH CORPORATION) in a trimethylolpropane adduct of (H-2) tolylene diisocyanate,

(H-3) 3-glycidoxypropyltrimethoxysilane, liquid (KBM-403 (trade name), Shin-Etsu Chemical Co., Ltd.)

(2) Preparation of pressure-sensitive adhesive 1

100 parts by mass of the acrylic base polymer (H-1), 0.2 parts by mass of an isocyanate crosslinking agent (H-2), and 0.2 parts by mass of a silane coupling agent (H-3) were mixed and sufficiently stirred, diluted with ethyl acetate To prepare a pressure-sensitive adhesive 1.

[Measurement of viscosity]

With respect to the adhesives 1 to 11 prepared above, the viscosity at 25 ° C and 10 rpm was measured using an E-type viscometer "TVE-25" manufactured by Toki Sangyo K.K. The results are shown in Table 1.

[Production example of composite retardation plate]

(1) Production of first composite retarder (Examples 1 to 12 and Comparative Example 1)

(First retardation layer) composed of three layers of a retardation layer, a liquid crystal layer, an orientation layer, and a base layer, and a retardation layer, which is a liquid crystal layer, an orientation layer, The first retardation layer, the adhesives (adhesive 1 to 11) shown in Table 2, and the second retardation layer were laminated in the order of the retardation of each retardation layer And the expression layers were inwardly laminated in this order. Then, a laminate was obtained by sheet-joining these sheets. Thereafter, an ultraviolet irradiation apparatus having an ultraviolet lamp "H bulb" manufactured by Fusion UV Systems Co., Ltd. was used on both sides of the laminate, mW / cm &lt; 2 &gt; and an integrated amount of light at a wavelength of 280 to 320 nm of 400 mJ / cm &lt; 2 &gt; to cure the photocurable adhesive to form a cured layer to obtain a laminate. The first base layer and the second base layer were peeled off from the obtained laminate to obtain test pieces of composite retardation plates (Examples 1 to 12 and Comparative Example 1).

(2) Production of first composite retarder (Comparative Examples 2 and 3)

(First retardation layer) composed of three layers of a retardation layer, which is a liquid phase layer, an orientation layer and a base layer, and a retardation layer, which is a liquid crystal layer, and an orientation layer, The first retardation layer, the pressure-sensitive adhesive 1, and the second retardation layer were laminated on the respective retardation layers (first retardation layer, second retardation layer, and second retardation layer) And the phase difference manifesting layer was inward, and laminated in this order. Then, they were sheet-laminated to obtain a laminate. The test pieces of the composite retardation plates (Comparative Examples 2 and 3) were obtained after peeling the first base layer and the second base layer from the obtained laminate.

(3) Production of second composite retarder (Examples 13 to 24 and Comparative Example 4)

(The first retardation layer) and the "(3-2) retardation layer production example (2)" prepared in the above "(3-1) (Second retardation layer) prepared in Example 1 was cut into small pieces of 100 x 100 mm, and the first retardation layer, the adhesives (adhesive 1 to 11) shown in Table 3, and the second retardation layer And the retardation layer of the retardation layer was inward, and laminated in this order. Then, a laminate was obtained by sheet-joining them, and thereafter, an ultraviolet light irradiation apparatus with an ultraviolet lamp "H bulb" manufactured by Fusion UV Systems Co., Ltd. was used on both sides of the laminate to measure a light irradiation intensity of 400 mW / Curing the photocurable adhesive by irradiating ultraviolet light so that the accumulated light quantity at a wavelength of 280 to 320 nm was 400 mJ / cm2 to form a cured layer to obtain a laminate. The test piece of the compound phase difference plate (Examples 13 to 24 and Comparative Example 4) was obtained after peeling the first base layer and the second base layer from the obtained laminate.

(4) Production of second composite retarder (Comparative Examples 5 and 6)

(3-1) a retardation-dispersed 1/4 wavelength layer (first retardation layer) prepared in the above-mentioned &quot; (3-1) Production example (1) ) Positive C layer (second retardation layer) prepared in Production Example (2) of retardation layer (2) was cut into pieces of 100x100 mm, and the first retardation layer, the pressure-sensitive adhesive 1 and the second retardation layer Were laminated in this order so that the retardation layer of the retardation layer of the retardation layer was the inside. Then, they were sheet-laminated to obtain a laminate. The first base layer and the second base layer were peeled from the obtained laminate to obtain test pieces of composite retardation plates (Comparative Examples 5 and 6).

(5) Measurement of thickness of composite retardation plate and adhesive layer

The thickness of the test piece of the composite retarder produced as described above was measured with a contact type film thickness meter (trade name " DIGIMICRO MH-15M ", manufactured by Nikon Corporation). Further, the thickness of the cured adhesive layer or pressure-sensitive adhesive layer was measured in the same manner as the above-mentioned method. The measurement results are shown in Tables 2 and 3.

(6) Measurement of stiction inclination in a compound retarder

The stiction slope of the test piece of the composite retarder produced above was calculated. The sticking strength was measured using a small tablet machine equipped with a piercing jig having a diameter of 1 mm and a radius of curvature of 0.5 R at the tip ("EZ Test", manufactured by Shimadzu Corporation). The obtained stiction intensity A (kg), the stuck depth B (mm) to be torn, and the composite retardation plate thickness d (mm)

E = A / (B x d)

Was used to calculate the steeper slope E (kg / mm &lt; 2 &gt;) per unit film thickness. The stippling slope of the composite retarder was an average value of the steeper slopes E of five or more composite retarder plates manufactured under the same conditions. The measurement results are shown in Tables 2 and 3.

[Production example of optical laminate]

(7) Production of Polarizer

A polyvinyl alcohol film having an average degree of polymerization of about 2,400 and a degree of saponification of 99.9 mol% or more and having a thickness of 75 탆 was immersed in pure water at 30 캜 and immersed in an aqueous solution having a mass ratio of iodine / potassium iodide / water of 0.02 / To perform iodine staining (iodine staining step). The polyvinyl alcohol film subjected to the iodine dyeing process was immersed in an aqueous solution having a mass ratio of potassium iodide / boric acid / water of 12/5/100 at 56.5 占 폚 to perform boric acid treatment (boric acid treatment step). The polyvinyl alcohol film having been subjected to the boric acid treatment step was washed with pure water at 8 占 폚 and then dried at 65 占 폚 to obtain a polarizer (thickness after stretching: 27 占 퐉) in which iodine was adsorbed and aligned in polyvinyl alcohol. At this time, stretching was carried out in the iodine dyeing step and the boric acid treatment step. The total draw ratio at this stretching was 5.3 times. A saponified triacetylcellulose film (trade name: KC4UYTAC, manufactured by Konica Minolta, thickness 40 占 퐉) was bonded to both surfaces of the obtained polarizer with a nip roll through an aqueous adhesive. The resulting laminate was dried at 60 DEG C for 2 minutes while maintaining the tensile force at 430 N / m to obtain a polarizer having a triacetylcellulose film as a protective film on both sides. The water-based adhesive described above was prepared by mixing 100 parts of water with 3 parts of a carboxyl group-modified polyvinyl alcohol (Kurarupofal KL318, Kuraray Co., Ltd.) and 30 parts of a water-soluble polyamide epoxy resin (Sumirez resin 650, By weight aqueous solution).

(8) Production of first optical laminate (Examples 1 to 12 and Comparative Examples 1 to 3)

The polarizing plate prepared in (7) above and the first composite retardation plate prepared in (1) or (2) were laminated on the first retardation plate so that the first retardation layer side was an adhesive surface, Mu m) to produce a first optical laminate. More specifically, the slow axis of the first retardation layer was laminated so that the counterclockwise direction was -15 ° with respect to the absorption axis direction (0 °) of the polarizing plate prepared above, And the transmission axis of one polarization plate and the retardation axis of the second retardation layer were -75 °.

(9) Production of second optical laminate (Examples 13 to 24 and Comparative Examples 4 to 6)

A second optical laminate was produced using the polarizing plate prepared in (8) above and the second composite retarder prepared in (3) or (4). Specifically, the polarizing plate prepared above was cut into small pieces of 100 × 100 mm such that the slow axis of the first retardation layer was 45 ° with respect to the absorption axis direction (0 °) of the polarizer, The retardation plate was sheet-joined using an acrylic pressure-sensitive adhesive (film thickness: 25 mu m) so that the first retardation layer side was an adhesive surface to produce an optical laminate as a circularly polarizing plate.

[Test Example] (Wrinkle occurrence evaluation)

The first optical laminate prepared in (8) and the second optical laminate prepared in (9) were laminated on the flexure 2R (2R) using an acrylic pressure-sensitive adhesive (film thickness 25 mu m) ), And the occurrence of wrinkles at the bent portions was visually observed. The occurrence of wrinkles was evaluated based on the following criteria. The evaluation results are shown in Tables 2 and 3.

1: no wrinkles were found in the knee,

2: It was confirmed that there was a slight wrinkle in the knee (the number of wrinkles: 1 to 5 lines)

3: It has been confirmed that there is wrinkles in the bend (number of wrinkles: 5 lines or more).

1: first retardation layer, 2: second retardation layer, 4: first adhesive layer, 5: composite retardation plate, 10: first retardation layer, 11: first base layer, 12: first alignment layer, 13: A second retardation layer, and a second retardation layer, wherein the first retardation layer and the second retardation layer are laminated on a glass substrate, W: Width direction.

Claims (13)

A first retardation layer, a second retardation layer, and a first adhesive layer for bonding the first retardation layer and the second retardation layer,
A composite retardation plate having a stiction slope of 6 kg / mm &lt; 2 &gt; to 15 kg / mm &lt; 2 &gt; per unit film thickness. The compound retarder according to claim 1, wherein the first adhesive layer is a cured layer of an active energy ray-curable adhesive. 3. The compound retarder according to claim 1 or 2, wherein the first retardation layer is a half-wave layer and the second retardation layer is a quarter-wave layer. 3. The compound retarder according to claim 1 or 2, wherein the first retardation layer is a 1/2 wavelength layer or a 1/4 wavelength layer and the second retardation layer is an optical compensation layer. The compound retarder according to any one of claims 1 to 4, wherein at least one of the first retardation layer and the second retardation layer comprises a phase difference reproduction layer which is a liquid crystal layer. 6. The composite retarder according to any one of claims 1 to 5, wherein the thickness of the composite retarder is 2 占 퐉 to 50 占 퐉. A liquid crystal display comprising a polarizing plate and the compound retarder according to any one of claims 1 to 6 laminated on the polarizing plate,
Wherein the compound retarder is laminated in a direction in which the first retardation layer is located on the polarizing plate side. The optical laminate according to claim 7, which is a circularly polarizing plate. The optical laminate according to claim 7 or 8, further comprising a second adhesive layer for bonding the polarizing plate and the compound retarder. The optical laminate according to claim 9, wherein the second adhesive layer is a cured layer of an active energy ray-curable adhesive. An image display apparatus comprising the image display panel and the optical laminate according to any one of claims 7 to 10 arranged on the viewer side of the image display panel. The image display apparatus according to claim 11, wherein the optical laminate is disposed in a direction in which the polarizing plate is positioned on the viewer side. The image display device according to claim 12, which is an organic electroluminescence display device.

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