Stacked body and image display device using the same

Abstract

A laminate and an image display device are provided. The laminate has a polarizing plate including a polarizing member, a functional layer, a resin layer, and an adhesive layer, the resin layer and the adhesive layer are disposed adjacent to each other, the resin layer contains a resin having a glass transition temperature of 85°C or higher and a weight average molecular weight Mw of 50,000 or more and less than 500,000 and an isocyanate compound, the isocyanate compound contains at least one selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and derivatives thereof, the content of the resin in the resin layer is 50% by weight or more and 90% by weight or less, the content of the isocyanate compound in the resin layer is 10% by weight or more and 50% by weight or less, the adhesive layer is composed of a cured product layer of an adhesive composition, and the octanol / water partition coefficient logPow calculated by weighted average of the mole fraction of a monomer component contained in the adhesive composition is 1.5 or more and 4.0 or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a laminate and an image display device using the same. BACKGROUND

[0002] In recent years, image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (for example, organic EL display devices, inorganic EL display devices) are rapidly spreading. A polarizing plate is generally used in an image display panel mounted on an image display device. As a representative example, a laminate in which a polarizing plate and a functional layer such as a retardation layer are integrated is widely used (for example, Patent Document 1). In recent years, the demand for thinning of image display devices has become stronger, and thinning of the above-described laminate is also strongly demanded.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent No. 3325560 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] With thinning of the above-described laminate, sometimes the adhesion between members constituting the laminate cannot be sufficiently ensured.

[0008] The present application has been made in view of the above-described circumstances, and a main object thereof is to provide a laminate which is thin and excellent in adhesion between members.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] 1. A laminate according to an embodiment of the present application has a polarizing plate including a polarizing member, a functional layer, and a resin layer and an adhesive layer disposed between the polarizing plate and the functional layer, the resin layer and the adhesive layer are disposed in contact with each other, the resin layer contains a resin having a glass transition temperature of 85°C or higher and a weight average molecular weight Mw of 50,000 or more and less than 500,000, and an isocyanate compound, the isocyanate compound contains at least one selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and derivatives thereof, the content of the resin in the resin layer is 50% by weight or more and 90% by weight or less, the content of the isocyanate compound in the resin layer is 10% by weight or more and 50% by weight or less, the adhesive layer is composed of a cured product layer of an adhesive composition, and the octanol / water partition coefficient logPow calculated by weighted average of the mole fraction of a monomer component contained in the adhesive composition is 1.5 or more and 4.0 or less.

[0011] 2. The laminate according to claim 1, wherein the content of the monomer component having a log Pow of 0.0 or less is 30 parts by weight or less, relative to 100 parts by weight of the monomer component contained in the adhesive composition.

[0012] 3. The laminate according to claim 1 or 2, wherein the resin layer further contains at least one of hexamethylene diisocyanate or a derivative thereof as the isocyanate compound.

[0013] 4. The laminate according to any one of claims 1 to 3, wherein the thickness of the adhesive layer is 3 μm or less.

[0014] 5. The laminate according to any one of claims 1 to 4, wherein the thickness of the resin layer is 1 μm or less.

[0015] 6. The laminate according to any one of claims 1 to 5, wherein the resin layer is disposed in contact with the polarizing member.

[0016] 7. The laminate according to any one of claims 1 to 6, wherein the functional layer is a retardation layer.

[0017] 8. An image display device according to an embodiment of the present application, comprising the laminate according to any one of claims 1 to 7.

[0018] 9. A method for producing a laminate according to an embodiment of the present application, comprising: forming a resin layer by applying an organic solvent solution containing a resin and an isocyanate compound to a functional layer or a polarizing plate containing a polarizing member; and adhering the functional layer or the polarizing plate to the resin layer by means of an adhesive composition, the glass transition temperature of the resin being 85°C or higher and the weight average molecular weight Mw being 50,000 or more and less than 500,000, the isocyanate compound containing at least one selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and derivatives thereof, the content of the resin in the resin layer being 50% by weight or more and 90% by weight or less, the content of the isocyanate compound in the resin layer being 10% by weight or more and 50% by weight or less, and the log Pow calculated by the weighted average of the mole fraction of the monomer component contained in the adhesive composition being 1.5 or more and 4.0 or less.

[0019] Effects of the Invention

[0020] According to the embodiment of the present application, a laminate which is thin and has excellent adhesion between members can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A cross-sectional schematic view showing the outline configuration of the laminate according to one embodiment of the present application.

[0022] Figure 2 A cross-sectional schematic view showing the schematic configuration of an image display panel of one embodiment of the present application.

[0023] Figure 3 A cross-sectional SEM observation photograph of Example 1.

[0024] Figure 4 A cross-sectional SEM observation photograph of Comparative Example 1.

[0025] Explanation of Reference Numerals

[0026] 10 Polarizing plate

[0027] 11 Polarizing member

[0028] 12 Protective layer

[0029] 20 Resin layer

[0030] 30 Adhesive layer

[0031] 40 Functional layer

[0032] 100 Layered body DETAILED DESCRIPTION

[0033] Embodiments of the present application will be described below with reference to the drawings, but the present application is not limited to these embodiments. Note that the drawings are for the purpose of making the description clearer, and thus the width, the thickness, the shape, and the like of each portion are schematically shown in some cases compared with the embodiments, which is one example and does not limit the explanation of the present application.

[0034] (Definition of Terms and Symbols)

[0035] The definition of terms and symbols in this specification is as follows.

[0036] (1) Refractive index (nx, ny, nz)

[0037] "nx" is the refractive index of the direction in which the in-plane refractive index is the largest (i.e., the slow axis direction), "ny" is the refractive index of the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction.

[0038] (2) In-plane retardation (Re)

[0039] "Re(λ)" is the in-plane retardation measured at 23 °C with light having a wavelength of λ nm. For example, "Re(550)" is the in-plane retardation measured at 23 °C with light having a wavelength of 550 nm. For Re(λ), when the thickness of a layer (film) is set to d (nm), it is calculated by the formula: Re(λ) = (nx - ny) x d.

[0040] (3) Phase difference in thickness direction (Rth)

[0041] “Rth(λ)” is a phase difference in thickness direction measured at 23°C using light of wavelength λ nm. For example, “Rth(550)” is a phase difference in thickness direction measured at 23°C using light of wavelength 550 nm. For Rth(λ), when the thickness of a layer (film) is set as d (nm), it is calculated by the formula: Rth(λ) = (nx - nz) x d.

[0042] (4) Nz coefficient

[0043] The Nz coefficient is calculated by Nz = Rth / Re.

[0044] (5) Angle

[0045] When an angle is mentioned in the present specification, the angle includes both clockwise and counterclockwise with respect to a reference direction. Thus, for example, “45°” means ±45°.

[0046] A. Laminated body

[0047] Figure 1 A cross-sectional schematic view showing the outline configuration of a laminated body of one embodiment of the present application. The laminated body 100 has, in order from the upper side of the Figure 1 polarizing plate 10, a resin layer 20, an adhesive layer 30, and a functional layer 40.

[0048] The polarizing plate 10 includes a polarizing member 11 having a first main surface 11a and a second main surface 11b opposite to each other, and further includes a protective layer 12 provided on the first main surface 11a side of the polarizing member 11. In the illustrated example, the protective layer is not provided between the polarizing member 11 and the resin layer 20, and the resin layer 20 is provided in contact with the polarizing member 11. By omitting the protective layer, thinning of the laminated body can be facilitated. The laminated body 100 is typically provided in an image display device in such a manner that the polarizing member 11 is on the visually recognized side as compared with the resin layer 20.

[0049] In the illustrated example, the polarizing plate 10 includes the polarizing member 11 and the protective layer 12 provided on the first main surface 11a side of the polarizing member 11, and can further include a second protective layer provided on the second main surface 11b side of the polarizing member 11. In addition, the polarizing plate 10 includes the polarizing member 11 and the protective layer 12, but the protective layer 12 can be omitted.

[0050] In the illustrated example, the polarizing plate 10, the resin layer 20, the adhesive layer 30, and the functional layer 40 are provided in this order, but the adhesive layer 30 can be provided on the polarizing plate 10 side and the resin layer 20 can be provided on the functional layer 40 side, instead of the illustrated example.

[0051] The resin layer 20 is disposed in contact with the adhesive layer 30. It is preferable that an interface be confirmed between the resin layer 20 and the adhesive layer 30. Alternatively, it is preferable that no intermediate layer containing a component derived from the resin layer 20 and a component derived from the adhesive layer be formed between the resin layer 20 and the adhesive layer 30. The intermediate layer can be formed, for example, by a portion of the resin layer dissolving (dissolving) in the adhesive composition forming the adhesive layer when the adhesive layer is formed. By adopting a state in which an interface is formed (no intermediate layer is formed), excellent adhesiveness to the resin layer can be obtained without impairing the function possessed by the resin layer. Confirmation of the interface or the intermediate layer can be performed, for example, by observation with a scanning electron microscope (SEM).

[0052] The functional layer 40 can be composed of any appropriate optical member. Typically, the functional layer 40 can function as a phase difference layer. In this case, the laminate 100 is sometimes referred to as a polarizing plate with a phase difference layer. By using the adhesive layer in the lamination of the resin layer and the functional layer or the polarizing plate, the thickness of the adhesive layer between the resin layer and the functional layer or the polarizing plate can be made very thin (for example, less than 5 μm), which greatly contributes to the thinness of the laminate. In addition, the obtained laminate is also excellent in flexibility.

[0053] Although not illustrated, the laminate (polarizing plate with a phase difference layer) can also have other functional layers. The kind, properties, number, combination, arrangement, and the like of the other functional layers that the laminate can have can be appropriately set according to the purpose. For example, the resin layer 20 can reduce the influence of the polarizing member 11 on other members, and the laminate can also have such a resin layer. In addition, for example, the polarizing plate with a phase difference layer can also have a conductive layer or an isotropic substrate with a conductive layer. The polarizing plate with a phase difference layer having a conductive layer or an isotropic substrate with a conductive layer is suitable, for example, for a so-called built-in touch panel type input display device in which a contact type sensor is incorporated inside an image display panel. As another example, the polarizing plate with a phase difference layer can also have other phase difference layers. The optical properties (for example, refractive index properties, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement, and the like of the other phase difference layers can be appropriately set according to the purpose. As a specific example, an other phase difference layer (typically, a layer imparting (elliptical) circularly polarizing function, a layer imparting ultra-high phase difference) for improving visual recognition when visual recognition is performed through a polarizing sunglass can be provided on the visual recognition side of the polarizing member. By having such a layer, even in the case where a display screen is visually recognized through a polarizing lens such as a polarizing sunglass, excellent visual recognition can be achieved, and the polarizing plate with a phase difference layer can be suitably applied to an image display device that can be used outdoors.

[0054] The respective members constituting the laminate can be laminated by means of any appropriate adhesive layer. As specific examples of the adhesive layer, an adhesive layer, an adhesive agent layer can be given. For example, the protective layer 12 is attached to the polarizing member 11 by means of an adhesive layer (preferably, an active energy ray-curable adhesive is used). The thickness of the adhesive layer is, for example, 0.05 μm or more, preferably 0.4 μm to 3.0 μm, more preferably 0.6 μm to 2.2 μm.

[0055] Although not illustrated, an adhesive layer can also be provided on the side of the functional layer 40 on which the polarizing plate 10 is not disposed, and the laminate 100 can be attached to an image display panel included in an image display device by means of the adhesive layer, for example. The thickness of the adhesive layer is preferably 10 μm to 20 μm.

[0056] The laminate can be in a sheet shape or in a strip shape. The "strip shape" in the present specification means an elongated shape in which the length is sufficiently long with respect to the width, and includes, for example, an elongated shape in which the length is 10 times or more, preferably 20 times or more, with respect to the width. The laminate in a strip shape can be wound in a roll shape.

[0057] B. Polarizing plate

[0058] The above-described polarizing plate includes a polarizing member having a first main surface and a second main surface opposing each other, and can further include a protective layer disposed on the first main surface side and / or a second protective layer disposed on the second main surface side.

[0059] B-1. Polarizing member

[0060] The above-described polarizing member is typically composed of a polyvinyl alcohol (PVA)-based resin film containing a dichroic substance. The thickness of the polarizing member is preferably 1 μm to 8 μm, more preferably 1 μm to 7 μm, further preferably 2 μm to 5 μm. With such a thickness, for example, the thinning of the laminate can be greatly facilitated.

[0061] The boronic acid content of the polarizing member is preferably 10% by weight or more, more preferably 13% by weight to 25% by weight. When the boronic acid content of the polarizing member is in such a range, the ease of curl adjustment at the time of attachment is favorably maintained, and the curl at the time of heating is favorably suppressed, and the appearance durability at the time of heating can be improved, by the synergistic effect with the iodine content described later. The boronic acid content can be calculated as the amount of boronic acid contained in the polarizing member per unit weight, for example, using the following formula according to the neutralization method.

[0062]

[0063] The iodine content of the polarizing member is preferably 2% by weight or more, and more preferably 2% by weight to 10% by weight. When the iodine content of the polarizing member is in this range, the ease of curl adjustment at the time of bonding is favorably maintained, and curl at the time of heating is favorably suppressed, and the appearance durability at the time of heating is improved, by the synergistic effect with the above-described boron acid content. The "iodine content" in this specification refers to the amount of all iodine contained in the polarizing member (PVA-based resin film). More specifically, when iodine exists in the polarizing member in the form of iodide ions (I - ), iodine molecules (I2), polyiodide ions (I3 - , I5 - ), and the like, the iodine content in this specification refers to the amount of iodine including all of these forms. The iodine content can be calculated, for example, by the standard curve method of fluorescent X-ray analysis. Note that the polyiodide ions exist in the polarizing member in a state of forming a PVA-iodine complex. By forming such a complex, absorption dichroism can be exhibited in the wavelength range of visible light. Specifically, the complex of PVA and triiodide ions (PVA-I3 - ) has an absorption peak around 470 nm, and the complex of PVA and pentaiodide ions (PVA-I5 - ) has an absorption peak around 600 nm. As a result, the polyiodide ions can absorb light in a wide range of visible light depending on the form thereof. On the other hand, the iodide ions (I - ) have an absorption peak around 230 nm, and do not substantially interfere with the absorption of visible light. Therefore, the polyiodide ions existing in the state of a complex with PVA mainly interfere with the absorption performance of the polarizing member.

[0064] The polarizing member preferably exhibits absorption dichroism at any wavelength in the wavelength range of 380 nm to 780 nm. The monomer transmittance Ts of the polarizing member is preferably 40% to 48%, and more preferably 41% to 46%. The polarizing degree P of the polarizing member is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more. The monomer transmittance is typically the Y value measured using an ultraviolet-visible spectrophotometer and subjected to visual sensitivity correction. The polarizing degree is typically calculated from the parallel transmittance Tp and the orthogonal transmittance Tc obtained by measuring using an ultraviolet-visible spectrophotometer and subjected to visual sensitivity correction, by the following formula.

[0065] Polarizing degree (%) = {(Tp - Tc) / (Tp + Tc)} 1 / 2 x 100

[0066] The polarizing member is typically produced using a laminate of two or more layers. As a specific example of a polarizing member produced using a laminate, a polarizing member produced using a laminate of a resin substrate and a PVA-based resin layer formed by coating the resin substrate can be given. A polarizing member produced using a laminate of a resin substrate and a PVA-based resin layer formed by coating the resin substrate can be produced, for example, by coating a PVA-based resin solution on a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, and thereby obtaining a laminate of the resin substrate and the PVA-based resin layer; and stretching and dyeing the laminate to produce a polarizing member from the PVA-based resin layer. The stretching typically involves immersing the laminate in an aqueous boric acid solution and stretching it. The stretching can further include, as needed, aerial stretching of the laminate at a high temperature (e.g., 95°C or higher) before the stretching in the aqueous boric acid solution. The obtained laminate of the resin substrate / polarizing member can be used as is (i.e., the resin substrate can be used as a protective layer for the polarizing member), or the resin substrate can be peeled from the laminate of the resin substrate / polarizing member, and a suitable protective layer of any desired purpose can be laminated on the peeled surface and used. Details of such a method for producing a polarizing member are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0067] The method for producing a polarizing member typically includes: forming a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin on one side of a strip-shaped thermoplastic resin substrate to produce a laminate; and sequentially performing on the laminate: an aerial auxiliary stretching process, a dyeing process, an underwater stretching process, and a drying shrinkage process in which the laminate is heated while being transported in the longitudinal direction to cause it to shrink by 2% or more in the width direction. Thus, a very thin polarizing member having excellent optical properties and a small variation in the optical properties can be provided. That is, by introducing the auxiliary stretching, the crystallinity of the PVA can be improved even when the PVA is coated on the thermoplastic resin, and high optical properties can be achieved. In addition, the orientation of the PVA is improved in advance, and thus, when the laminate is immersed in water in the subsequent dyeing process and stretching process, the orientation of the PVA can be prevented from decreasing, and problems such as dissolution can be prevented, and high optical properties can be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, the orientation of the polyvinyl alcohol molecules can be prevented from being disturbed and the orientation can be prevented from decreasing, as compared with the case where the PVA-based resin layer does not contain a halide. Thus, the optical properties of the polarizing member obtained by the processes of immersing the laminate in a liquid such as the dyeing process and the underwater stretching process can be improved. Furthermore, by causing the laminate to shrink in the width direction using the drying shrinkage process, the optical properties can be improved.

[0068] B-2. Protective layer

[0069] The protective layer 12 and the second protective layer not shown are each formed of an arbitrary appropriate film that can be used as a protective layer of a polarizing member. As a specific example of a material that is a main component of the film, a transparent resin such as a cellulose-based resin such as triacetyl cellulose (TAC), a polyester-based resin, a polyvinyl alcohol-based resin, a polycarbonate-based resin, a polyamide-based resin, a polyimide-based resin, a polyethersulfone-based resin, a polysulfone-based resin, a polystyrene-based resin, a cyclic olefin-based resin (for example, a polynorbornene-based resin), a polyolefin-based resin, a (meth)acrylic-based resin, an acetate-based resin, or the like can be given. In addition, a thermosetting resin such as a (meth)acrylic-based resin, a urethane-based resin, a (meth)acrylic urethane-based resin, an epoxy-based resin, a silicone-based resin, or the like, or an ultraviolet-curable resin, or the like can also be given. Furthermore, for example, a vitreous polymer such as a silicone-based polymer can also be given. In addition, a polymer film described in Japanese Patent Application Publication No. 2001-343529 (WO 01 / 37007) can also be used. As the material of the film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in a side chain can be used, for example, a resin composition having an alternating copolymer formed of isobutylene and N-methyl maleimide and an acrylonitrile-styrene copolymer can be given. The polymer film can be, for example, an extrusion molded product of the above-described resin composition.

[0070] The laminate of the embodiment of the present application is typically disposed on the visually recognized side of the image display device, and the protective layer 12 is disposed on the visually recognized side. Therefore, the protective layer 12 can be subjected to surface treatment such as hard coat (HC) treatment, anti-reflection treatment, anti-blocking treatment, anti-glare treatment, or the like as needed. Furthermore / alternatively, the protective layer 12 can be subjected to treatment for improving visual recognition when visually recognized with polarized sunglasses (typically, imparting (elliptical) circularly polarizing function, imparting ultra-high phase difference) as needed. By subjecting to such treatment, even in a case where the display screen is visually recognized with a polarizing lens such as polarized sunglasses, excellent visual recognition can be achieved, and it is also suitable for application to an image display device that can be used outdoors.

[0071] The thickness of the protective layer is preferably 10 μm to 50 μm, and more preferably 10 μm to 30 μm. Note that in a case where surface treatment is performed, the thickness of the protective layer is the thickness including the thickness of the surface treatment layer.

[0072] The second protective layer is preferably optically isotropic in one embodiment. In the present specification, "optically isotropic" means that the in-plane phase difference Re(550) is 0 nm to 10 nm, and the thickness direction phase difference Rth(550) is -10 nm to +10 nm.

[0073] C. Resin Layer

[0074] The resin layer can reduce the influence (may have a barrier function) that the polarizing member can give to other members. For example, the movement of iodine that can be contained in the polarizing member can be suppressed, and in the case where the laminate is mounted on an image display device, corrosion of a metal member of the image display device can be significantly suppressed. The resin layer is typically a solidified product or a thermally cured product of a coating film of an organic solvent solution of a resin. In such a configuration, the thickness can be made very thin (for example, 10 μm or less). The thickness of the resin layer is preferably 5 μm or less, more preferably 1 μm or less, and further preferably 0.7 μm or less. On the other hand, the thickness of the resin layer is preferably 0.05 μm or more, more preferably 0.08 μm or more, further preferably 0.1 μm or more, and particularly preferably 0.2 μm or more. Furthermore, in such a configuration, the resin layer can be formed directly on the polarizing plate (polarizing member) or the functional layer without the aid of an adhesive layer. Such a resin layer has the advantage that the moisture absorption and the moisture permeability are small compared to a solidified product of a coating film of an aqueous system such as an aqueous solution or an aqueous dispersion, and thus has excellent moisture resistance. As a result, a laminate that can maintain optical properties even in a high-temperature high-humidity environment and has excellent durability can be obtained. In addition, such a resin layer can suppress adverse effects on the polarizing plate (polarizing member) caused by ultraviolet irradiation compared to a cured product of an ultraviolet-curable resin. The resin layer is preferably a solidified product of a coating film of an organic solvent solution of a resin. The solidified product has small shrinkage at the time of film formation compared to a cured product, and does not contain a residual monomer or the like, and thus the deterioration of the film itself can be suppressed, and adverse effects on the polarizing plate (polarizing member) or the functional layer caused by a residual monomer or the like can be suppressed.

[0075] The glass transition temperature (Tg) of the resin that constitutes the resin layer is 85°C or higher, and the weight average molecular weight (Mw) is 50,000 or higher. When the Tg and the Mw are in such ranges, by the synergistic effect of the effects brought about by the resin layer being constituted by a solidified product or a thermally cured product of a coating film of an organic solvent solution of a resin, not only is the thickness very thin, but the movement of iodine that can be contained in the polarizing member can be significantly suppressed. The Tg of the resin that constitutes the resin layer is preferably 90°C or higher, more preferably 100°C or higher, further preferably 110°C or higher, and particularly preferably 120°C or higher. The upper limit of the Tg can be, for example, 200°C. In addition, the Mw of the resin that constitutes the resin layer is preferably 60,000 or higher, more preferably 70,000 or higher, and further preferably 80,000 or higher. On the other hand, the Mw is preferably less than 500,000, preferably 400,000 or less, and further preferably 300,000 or less.

[0076] The resin layer contains an isocyanate compound in addition to the above-mentioned resin. Specifically, as the isocyanate compound, toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, derivatives thereof (e.g., modified products, addition products) are used. These can be used alone or in combination. By using such an isocyanate compound, excellent adhesion to the polarizing plate (polarizing member) can be achieved. In addition to the above-mentioned, at least one of hexamethylene diisocyanate or a derivative thereof is preferably used as the isocyanate compound. With such a configuration, the adhesion to the adhesive layer described later is more excellent.

[0077] The content of the resin in the resin layer is, for example, 50% by weight or more, and can be 55% by weight or more, or 60% by weight or more. On the other hand, the content of the resin in the resin layer is, for example, 90% by weight or less, and can be 85% by weight or less, or 80% by weight or less. The content of the isocyanate compound in the resin layer is, for example, 10% by weight or more, and can be 15% by weight or more, or 20% by weight or more. On the other hand, the content of the isocyanate compound in the resin layer is, for example, 50% by weight or less, and can be 45% by weight or less, or 40% by weight or less. The amount of hexamethylene diisocyanate and a derivative thereof is preferably 10 to 40 parts by weight with respect to 100 parts by weight of the isocyanate compound.

[0078] As the resin constituting the resin layer, any appropriate thermoplastic resin or thermosetting resin can be used as long as it can form a solidified or thermoset product of a coating film of an organic solvent solution, and has the Tg and Mw described above. A thermoplastic resin is preferred. As the thermoplastic resin, for example, an epoxy-based resin, an acrylic-based resin can be mentioned. An epoxy-based resin and an acrylic-based resin can be used in combination. Hereinafter, representative examples of the epoxy-based resin and the acrylic-based resin that can be used in the resin layer will be described.

[0079] <epoxy resin>

[0080] As the epoxy resin, it is preferable to use an epoxy resin having an aromatic ring. By using an epoxy resin having an aromatic ring as the epoxy resin, excellent adhesion to the polarizing plate (polarizing member) can be achieved. As the epoxy resin having an aromatic ring, for example, a bisphenol type epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a novolak type epoxy resin such as a phenol novolak epoxy resin, a cresol novolak epoxy resin, a hydroxybenzaldehyde phenol novolak epoxy resin, a multifunctional type epoxy resin such as a glycidyl ether of tetrahydroxyphenyl methane, a glycidyl ether of tetrahydroxybenzophenone, an epoxidized polyvinylphenol, a naphthol type epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, and the like can be mentioned. It is preferable to use a bisphenol A type epoxy resin, a biphenyl type epoxy resin, a bisphenol F type epoxy resin. The epoxy resin can be used alone or in combination of two or more.

[0081] <Acrylic Resin>

[0082] An acrylic resin is typically one that contains a repeating unit derived from a (meth)acrylate monomer having a linear or branched chain structure as a main component. In the present specification, (meth)acrylic acid refers to acrylic acid and / or methacrylic acid. The acrylic resin can contain a repeating unit derived from any appropriate comonomer as desired. As the comonomer, for example, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amide group-containing monomer, an aromatic ring-containing (meth)acrylate, a heterocycle-containing vinyl monomer can be mentioned. By appropriately setting the kind, number, combination, and copolymerization ratio of monomer units, and the like, an acrylic resin having the above-mentioned prescribed Tg and Mw can be obtained.

[0083] <Acrylic Resin Containing Boron>

[0084] The acrylic resin in one embodiment contains a copolymer (hereinafter sometimes referred to as an acrylic resin containing boron) obtained by polymerizing a monomer mixture containing more than 50 parts by weight of a (meth)acrylate monomer and more than 0 parts by weight and less than 50 parts by weight of a monomer represented by formula (1) (hereinafter sometimes referred to as a comonomer):

[0085]

[0086] (in the formula, X represents a functional group containing at least one reactive group selected from the group consisting of a vinyl group, a (meth)acryloyl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetanyl group, a hydroxyl group, an amino group, an aldehyde group, and a carboxyl group, R 1 and R 2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group optionally having a substituent, an aromatic group optionally having a substituent, or a heterocyclic group optionally having a substituent, R 1 and R2 optionally connected to each other to form a ring).

[0087] The boron-containing acrylic resin is represented by a repeating unit shown in the following formula. By polymerizing a monomer mixture containing a comonomer shown in the formula (1) and a (meth)acrylic monomer, the boron-containing acrylic resin has a substituent containing boron in a side chain (for example, a repeating unit of k in the following formula). Thus, excellent adhesion to a polarizing plate (polarizing member) can be achieved. The substituent containing boron can be contained continuously (i.e., in a block shape) or randomly in the boron-containing acrylic resin.

[0088]

[0089] (In the formula, R 6 represents an arbitrary functional group, and j and k represent an integer of 1 or more).

[0090] <(Meth)acrylic monomer>

[0091] As the (meth)acrylic monomer, any appropriate (meth)acrylic monomer can be used. For example, a (meth)acrylate monomer having a linear or branched chain structure, and a (meth)acrylate monomer having a cyclic structure can be mentioned.

[0092] As the (meth)acrylate monomer having a linear or branched chain structure, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, methyl 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and the like can be mentioned. Preferably, methyl (meth)acrylate can be used. The (meth)acrylate monomer can be used alone or in combination of two or more.

[0093] As the (meth)acrylate-based monomer having a cyclic structure, for example, (meth)acrylic acid cyclohexyl ester, (meth)acrylic acid benzyl ester, (meth)acrylic acid isobornyl ester, (meth)acrylic acid 1-adamantyl ester, (meth)acrylic acid dicyclopentenyl ester, (meth)acrylic acid dicyclopentenyl oxyethyl ester, (meth)acrylic acid dicyclopentyl ester, (meth)acrylic acid diphenyl ester, (meth)acrylic acid o-diphenyloxyethyl ester, (meth)acrylic acid o-diphenyloxyethoxyethyl ester, (meth)acrylic acid m-diphenyloxyethyl ester, (meth)acrylic acid p-diphenyloxyethyl ester, (meth)acrylic acid o-diphenyloxy-2-hydroxypropyl ester, (meth)acrylic acid p-diphenyloxy-2-hydroxypropyl ester, (meth)acrylic acid m-diphenyloxy-2-hydroxypropyl ester, N-(meth)acryloyloxyethyl-o-diphenyl=carbamate, N-(meth)acryloyloxyethyl-p-diphenyl=carbamate, N-(meth)acryloyloxyethyl-m-diphenyl=carbamate, o-phenylphenol glycidyl ether acrylate, and the like biphenyl group-containing monomers, (meth)acrylic acid terphenyl ester, (meth)acrylic acid o-terphenyloxyethyl ester, and the like can be mentioned. It is preferable to use (meth)acrylic acid 1-adamantyl ester, (meth)acrylic acid dicyclopentyl ester. By using these monomers, a polymer having a high glass transition temperature is obtained. These monomers can be used alone or in combination of two or more.

[0094] In addition, a silsesquioxane compound having a (meth)acryloyl group can be used in addition to the above-mentioned (meth)acrylate-based monomer. By using a silsesquioxane compound, an acrylic polymer having a high glass transition temperature is obtained. It is known that a silsesquioxane compound has various skeletal structures such as a cage structure, a ladder structure, a random structure, and the like. A silsesquioxane compound can have only one of these structures, or two or more. A silsesquioxane compound can be used alone or in combination of two or more.

[0095] As the silsesquioxane compound having a (meth)acryloyl group, for example, MAC series of SQ manufactured by Toagosei Co., Ltd. can be used. The MAC series is a silsesquioxane compound having a methacryloyl group, and specifically, for example, MAC-SQ TM-100, MAC-SQ SI-20, MAC-SQ HDM, and the like can be mentioned. The AC series is a silsesquioxane compound having an acryloyl group, and specifically, for example, AC-SQ TA-100, AC-SQ SI-20, and the like can be mentioned.

[0096] More than 50 parts by weight of the (meth)acrylic monomer is used with respect to 100 parts by weight of the monomer mixture.

[0097] <Comonomer>

[0098] As the comonomer, a monomer represented by the above formula (1) can be used. By using such a comonomer, a substituent containing boron is introduced in the side chain of the resulting polymer. The comonomer can be used alone or in combination of two or more.

[0099] As the aliphatic hydrocarbon group in the above formula (1), a linear or branched alkyl group having 1 to 20 carbon atoms optionally having a substituent, a cyclic alkyl group having 3 to 20 carbon atoms optionally having a substituent, an alkenyl group having 2 to 20 carbon atoms can be given. As the aryl group, a phenyl group having 6 to 20 carbon atoms optionally having a substituent, a naphthyl group having 10 to 20 carbon atoms optionally having a substituent, and the like can be given. As the heterocyclic group, a 5-membered ring group or a 6-membered ring group containing at least one hetero atom optionally having a substituent can be given. Note that, R 1 and R 2 optionally linked to each other to form a ring. R 1 and R 2 is preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom.

[0100] The reactive group contained in the functional group represented by X is at least one selected from the group consisting of a vinyl group, a (meth)acryloyl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetanyl group, a hydroxyl group, an amino group, an aldehyde group, and a carboxyl group. It is preferable that the reactive group be a (meth)acryloyl group and / or a (meth)acrylamide group. By having these reactive groups, excellent adhesion to a polarizing plate (polarizing member) can be achieved.

[0101] In one embodiment, the functional group represented by X is preferably a functional group represented by Z-Y-. Here, Z represents a functional group containing at least one reactive group selected from the group consisting of a vinyl group, a (meth)acryloyl group, a styryl group, a (meth)acrylamide group, a vinyl ether group, an epoxy group, an oxetanyl group, a hydroxyl group, an amino group, an aldehyde group, and a carboxyl group, and Y represents a phenylene group or an alkylene group.

[0102] As the comonomer, the following compounds can be specifically used.

[0103]

[0104] The comonomer is used in an amount of more than 0 parts by weight and less than 50 parts by weight with respect to 100 parts by weight of the monomer mixture. It is preferable that the amount be 0.01 parts by weight or more and less than 50 parts by weight, more preferable 0.05 parts by weight to 20 parts by weight, further preferable 0.1 parts by weight to 10 parts by weight, and particularly preferable 0.5 parts by weight to 5 parts by weight.

[0105] <Acrylic resin containing lactone ring>

[0106] The acrylic resin has, in another embodiment, a repeating unit containing a ring structure selected from the group consisting of a lactone ring unit, a glutaric anhydride unit, a glutarimide unit, a maleic anhydride unit, and a maleimide (N-substituted maleimide) unit. The repeating unit containing a ring structure can contain only one kind or two or more kinds among the repeating units of the acrylic resin.

[0107] The lactone ring unit is preferably represented by the following general formula (2):

[0108]

[0109] In the general formula (2), R 2 , R 3 , and R 4 each independently represent a hydrogen atom or an organic residue having a carbon number of 1 to 20. Note that the organic residue can contain an oxygen atom. The acrylic resin can contain only a single lactone ring unit or can contain a plurality of different lactone ring units in which R 2 , R 3 , and R 4 in the above general formula (2) are different. The acrylic resin having a lactone ring unit is described, for example, in Japanese Patent Application Publication No. 2008-181078, the description of which is incorporated herein by reference in its entirety.

[0110] The glutarimide unit is preferably represented by the following general formula (3):

[0111]

[0112] In the general formula (3), R 11 and R 12 each independently represent a hydrogen atom or an alkyl group having a carbon number of 1 to 8, R 13 represents an alkyl group having a carbon number of 1 to 18, a cycloalkyl group having a carbon number of 3 to 12, or an aryl group having a carbon number of 6 to 10. In the general formula (3), it is preferable that R 11 and R 12 each independently be a hydrogen atom or a methyl group, R 13 be a hydrogen atom, a methyl group, a butyl group, or a cyclohexyl group. It is more preferable that R 11 be a methyl group, R 12 be a hydrogen atom, and R 13 be a methyl group. The acrylic resin can contain only a single glutarimide unit or can contain a plurality of different glutarimide units in which R 11 , R 12 , and R 13different kinds of glutarimide units. Acrylic resins having a glutarimide unit are described, for example, in Japanese Patent Application Publication No. 2006-309033, Japanese Patent Application Publication No. 2006-317560, Japanese Patent Application Publication No. 2006-328334, Japanese Patent Application Publication No. 2006-337491, Japanese Patent Application Publication No. 2006-337492, Japanese Patent Application Publication No. 2006-337493, and Japanese Patent Application Publication No. 2006-337569, the disclosures of which are incorporated herein by reference. Note that, with respect to the glutaric anhydride unit, the above-described explanation regarding the glutarimide unit applies, except that the nitrogen atom substituted with R 13 The above-described explanation regarding the glutarimide unit applies, except that the nitrogen atom substituted with R

[0113] With respect to the maleic anhydride unit and the maleimide (N-substituted maleimide) unit, the structure is determined according to the name, and thus specific explanation is omitted.

[0114] The proportion of the repeating unit including a ring structure in the acrylic resin is preferably 1 mol% to 50 mol%, more preferably 10 mol% to 40 mol%, and further preferably 20 mol% to 30 mol%. Note that the acrylic resin includes a repeating unit derived from the above-described (meth) acrylic monomer as a main repeating unit.

[0115] The resin layer is typically formed by coating an organic solvent solution of the above-described resin, and is formed by solidifying or thermally curing the obtained coated film. As the organic solvent, any appropriate organic solvent that can dissolve or uniformly disperse the above-described resin can be used. As specific examples of the organic solvent, ethyl acetate, toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclopentanone, and cyclohexanone can be given. The resin concentration of the solution is preferably 3 parts by weight to 20 parts by weight with respect to 100 parts by weight of the solvent. With such a resin concentration, a uniform coated film can be formed.

[0116] The solution can be coated on any appropriate substrate, and is preferably coated on a polarizing plate (polarizing member) or a functional layer. In the case where the solution is coated on a substrate, the resin layer formed on the substrate is typically transferred to a polarizing plate (polarizing member) or a functional layer. The transfer is typically performed with the aid of an adhesive layer, and thus the resin layer can be directly formed by coating the solution on a polarizing plate (polarizing member) or a functional layer, omitting the adhesive layer. As the coating method of the solution, any appropriate method can be employed. As specific examples, roll coating, spin coating, wire bar coating, dip coating, die coating, curtain coating, spray coating, and knife coating (comma coating, etc.) can be given.

[0117] The heating temperature for solidification or thermal curing of the above-mentioned coated film is preferably 100°C or lower, more preferably 50°C to 70°C. When the heating temperature is in this range, adverse effects on the polarizing element can be prevented. The heating time can be, for example, 1 minute to 10 minutes.

[0118] The resin layer (essentially an organic solvent solution of the above-mentioned resin) can contain any appropriate additive as desired. As specific examples of the additive, there can be mentioned ultraviolet absorbers; leveling agents; antioxidants such as hindered phenol-based, phosphorus-based, and sulfur-based antioxidants; stabilizers such as light-resistant stabilizers, weather-resistant stabilizers, and heat-resistant stabilizers; reinforcing materials such as glass fibers and carbon fibers; near-infrared absorbers; flame retardants such as phosphoric acid tris(dibromopropyl) ester, phosphoric acid triallyl ester, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; colorants such as inorganic pigments, organic pigments, and dyes; organic fillers or inorganic fillers; resin modifiers; organic fillers or inorganic fillers; plasticizers; slip agents; antistatic agents; flame retardants; and the like. The kind, amount, combination, and addition amount of the additive can be appropriately set as desired.

[0119] D. Adhesive layer

[0120] The above-mentioned adhesive layer is preferably composed of a cured product of an adhesive composition. Specifically, it is preferably composed of a cured product of an active energy ray-curable adhesive composition (radical polymerization-curable adhesive composition) such as an electron beam-curable, ultraviolet-curable, or visible ray-curable adhesive composition. The thickness of the adhesive layer is preferably 3 μm or less, more preferably 2 μm or less. With such a thickness, the thinning of the laminate can be greatly facilitated. In addition, the influence on other members due to shrinkage that occurs when the adhesive layer is formed from the adhesive composition can be reduced. For example, from the viewpoint of obtaining excellent adhesion, the thickness of the adhesive layer is preferably 0.05 μm or more, more preferably 0.5 μm or more, and further preferably 1 μm or more.

[0121] As the monomer component constituting the radical polymerization-curable adhesive composition, for example, there can be mentioned a compound having a carbon-carbon double bond such as a (meth)acryloyl group or a vinyl group. These monomer components can use any of a monofunctional radical polymerizable compound or a multifunctional radical polymerizable compound having two or more polymerizable functional groups. In addition, these radical polymerizable compounds can be used alone or in combination with two or more kinds. Note that, in the present application, the (meth)acryloyl group means an acryloyl group and / or a methacryloyl group.

[0122] The octanol / water partition coefficient log Pow calculated by the weighted average of the molar fractions of the monomer components contained in the adhesive composition is, for example, 1.0 or greater and 4.0 or less, and is preferably 1.5 or greater, can be 2.0 or greater, or can be 2.5 or greater. By using such an adhesive composition, excellent adhesion to the resin layer can be obtained. Also, the function possessed by the resin layer (for example, barrier function) can be maintained. By using such an adhesive composition, the formation of the above-mentioned intermediate layer (compatibility layer) can be suppressed. Here, the octanol / water partition coefficient (log Pow) is an index indicating the lipophilicity of a substance, and refers to the logarithmic value of the octanol / water partition coefficient. A high log Pow can mean lipophilicity. The log Pow can be measured (for example, by the flask penetration method described in JIS-Z-7260), but can also be calculated. In this specification, the octanol / water partition coefficient (log Pow) refers to the value calculated using Chem Draw Ultra manufactured by CambridgeSoft. With respect to the resin layer of a solidified or thermally cured product of a coated film of an organic solvent solution of a resin that can be a resin, by using an adhesive composition having high hydrophobicity, the formation of the above-mentioned intermediate layer can be suppressed, and excellent adhesion can be obtained, which is an unexpectedly excellent effect.

[0123] The following shows log Pow of the radical polymerizable compounds. For example, hydroxyethyl acrylamide (trade name "HEAA", manufactured by KAYAKU CHEMICAL CO., LTD., Log Pow; -0.56), diethyl acrylamide (trade name "DEAA", manufactured by KJ Chemicals Corporation, Log Pow; 1.69), unsaturated fatty acid hydroxyalkyl ester-modified ε-caprolactone (trade name "PLACCEL FA1DDM", manufactured by Daicel Corporation, Log Pow; 1.06), N-vinyl formamide (trade name "BEAMSET 770", manufactured by Arakawa Chemical Industries, Ltd., Log Pow; -0.25), acryloylmorpholine (trade name "ACMO", manufactured by KAYAKU CHEMICAL CO., LTD., Log Pow; -0.20), γ-butyrolactone acrylate (trade name "GBLA", manufactured by Osaka Organic Chemical Industry Ltd., Log Pow; 0.19), acrylic acid dimer (trade name "β-CEA", manufactured by Daicel Corporation, Log Pow; 0.2), N-vinyl pyrrolidone (trade name "NVP", manufactured by NIPPON SHOKUBAI CO., LTD., Log Pow; 0.24), acryloyloxyethyl acetoacetate (trade name "AAEM", manufactured by NIPPON GLICO CO., LTD., Log Pow; 0.27), 2-hydroxyethyl acrylate (trade name "HEA", manufactured by Osaka Organic Chemical Industry Ltd., Log Pow; 0.28), glycidyl methacrylate (trade name "Light Ester G", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 0.57), dimethyl acrylamide (trade name "DMAA", manufactured by KAYAKU CHEMICAL CO., LTD., Log Pow; 0.58), tetrahydrofurfuryl alcohol acrylate dimer (trade name "VISCOAT #150D", manufactured by Osaka Organic Chemical Industry Ltd., Log Pow; 0.60), 4-hydroxybutyl acrylate (trade name "4-HBA", manufactured by Osaka Organic Chemical Industry Ltd., Log Pow; 0.68), acrylic acid (trade name "Acrylic Acid", manufactured by Mitsubishi Chemical Corporation, Log Pow; 0.69), triethylene glycol diacrylate (trade name "LIGHT ACRYLATE 3EG-A", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 0.72), PEG400# diacrylate (trade name "LIGHT ACRYLATE 9EG-A", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; -0.1), polypropylene glycol diacrylate (trade name "ARONIX M-220", manufactured by TOAGOSEI CO., LTD., Log Pow; 1.68), dicyclopentenyl acrylate (trade name "FANCRYL FA-511AS", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 2.26), butyl acrylate (trade name "Butyl Acrylate", manufactured by Mitsubishi Chemical Corporation, Log Pow; 2.35), 1,6-hexanediol diacrylate (trade name "LIGHT ACRYLATE 1.6HX-A", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 2.43), dicyclopentyl acrylate (trade name "FANCRYL FA-513AS", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 2.58), dimethylol-tricyclodecane diacrylate (trade name "LIGHT ACRYLATE DCP-A", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 3.05), isobornyl acrylate (trade name "LIGHT ACRYLATE IB-XA", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 3.27), hydroxypivalic acid neopentyl glycol acrylate adduct (trade name "LIGHT ACRYLATE HPP-A", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 3.35), 1,9-nonanediol diacrylate (trade name "LIGHT ACRYLATE 1,9ND-A", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 3.68), o-phenylphenol EO-modified acrylate (trade name "FANCRYL FA-301A", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 3.98), 2-ethylhexyloxetane (trade name "Aron Oxetane OXT-212", manufactured by Toagosei Co., Ltd., Log Pow; 4.24), bisphenol-A-diglycidyl ether (trade name "JER828", manufactured by Mitsubishi Chemical Corporation, Log Pow; 4.76), bisphenol A EO 6 mole-modified diacrylate (trade name "FA-326A", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 4.84), bisphenol A EO 4 mole-modified diacrylate (trade name "FA-324A", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 5.15), bisphenol A PO 2 mole-modified diacrylate (trade name "FA-P320A", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 6.10), bisphenol A PO 3 mole-modified diacrylate (trade name "FA-P323A", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 6.26), bisphenol A PO 4 mole-modified diacrylate (trade name "FA-P324A", manufactured by Hitachi Chemical Co., Ltd., Log Pow; 6.43), lauryl acrylate (trade name "LIGHT ACRYLATE L-A", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 6), isostearyl acrylate (trade name "ISTA"), manufactured by Osaka Organic Chemical Industry Ltd.; Log Pow; 7.46), phenoxydiethylene glycol acrylate (trade name "P2HA", manufactured by Kyoeisha Chemical Co., Ltd., Log Pow; 2.15) 2-hydroxy-3-phenoxypropyl acrylate (trade name "ARONIX M-5700", manufactured by Toagosei Co., Ltd., Log Pow; 1.17).

[0124] When the total amount of the monomer components included in the adhesive composition is set to 100 parts by weight, the content of the monomer component having an octanol / water partition coefficient log Pow of 0.0 or less can be 30 parts by weight or less. When the total amount of the monomer components included in the adhesive composition is set to 100 parts by weight, the content of the monomer component having an octanol / water partition coefficient log Pow of 2.0 or more can be 40 parts by weight or more.

[0125] The compounding amount of the polymerization initiator usable at the time of curing is, for example, 0.05 to 10% by weight, when the total amount of the adhesive composition is set to 100% by weight.

[0126] The curing of the adhesive composition can be performed, for example, by irradiating an active energy ray (e.g., visible light, ultraviolet light, electron beam) to a coated film of the adhesive composition.

[0127] E. Phase difference layer

[0128] The phase difference layer can be a single layer, or can have a laminated structure of two or more layers. The phase difference layer can be composed of any appropriate material. Specifically, the phase difference layer can be an oriented solidified layer of a liquid crystal compound, can be a stretched film (resin film), or can be a combination thereof. The thickness of the phase difference layer is, for example, 1 μm or more and 50 μm or less. In one embodiment, the thickness of the phase difference layer is preferably 10 μm or less, more preferably 8 μm or less, and further preferably 6 μm or less. According to the embodiment of the present application, even in the case where such an extremely thin phase difference layer is used, for example, in the case where the laminate is mounted on an image display device, corrosion of the metal member of the image display device can be significantly suppressed. Note that, in the case where the phase difference layer has a laminated structure, the "thickness of the phase difference layer" refers to the total of the thickness of each phase difference layer. Specifically, the "thickness of the phase difference layer" does not include the thickness of the adhesive layer.

[0129] As the above phase difference layer, for example, an oriented solidified layer of a liquid crystal compound (a liquid crystal oriented solidified layer) can be used. By using a liquid crystal compound, it is possible to significantly increase the difference between nx and ny of the resulting phase difference layer, for example, compared to a non-liquid crystal material, and thus it is possible to significantly reduce the thickness of the phase difference layer for obtaining a desired in-plane phase difference. Thus, it is possible to achieve a significant thinning of the polarizing plate with the phase difference layer. The "oriented solidified layer" in the present specification refers to a layer in which a liquid crystal compound is oriented in a prescribed direction within the layer, and the oriented state is fixed. Note that the "oriented solidified layer" is a concept that includes an oriented cured layer obtained by curing a liquid crystal monomer as described later. In the phase difference layer, typically, a rod-shaped liquid crystal compound is oriented in a state of being aligned in the slow axis direction of the phase difference layer (homogeneously oriented).

[0130] The above liquid crystal oriented solidified layer can be formed by subjecting the surface of a prescribed substrate to orientation treatment, coating the surface with a coating liquid containing a liquid crystal compound, and orienting the liquid crystal compound in a direction corresponding to the above orientation treatment, and fixing the oriented state. As the orientation treatment, any appropriate orientation treatment can be used. Specifically, mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment can be given. As specific examples of the mechanical orientation treatment, rubbing treatment and stretching treatment can be given. As specific examples of the physical orientation treatment, magnetic field orientation treatment and electric field orientation treatment can be given. As specific examples of the chemical orientation treatment, oblique vapor deposition and photo-orientation treatment can be given. The treatment conditions for each of the various orientation treatments can be any appropriate conditions according to the purpose.

[0131] The orientation of the liquid crystal compound is performed by treating at a temperature at which a liquid crystal phase is exhibited, according to the type of the liquid crystal compound. By performing such temperature treatment, the liquid crystal compound becomes in a liquid crystal state, and the liquid crystal compound is oriented according to the orientation treatment direction of the surface of the substrate.

[0132] For fixing the oriented state, in one embodiment, the liquid crystal compound that has been oriented as described above is cooled. In the case of a liquid crystal compound that is a polymerizable monomer or a cross-linkable monomer, fixing the oriented state is performed by subjecting the liquid crystal compound that has been oriented as described above to polymerization treatment or cross-linking treatment.

[0133] Specific examples of the liquid crystal compound and details of the method for forming the oriented solidified layer are described in Japanese Patent Application Publication No. 2006-163343. The description of this publication is incorporated herein by reference.

[0134] In one embodiment where the phase difference layer is a single layer, the phase difference layer can function as a λ / 4 plate. Specifically, the Re(550) of the phase difference layer is preferably from 100 nm to 180 nm, more preferably from 110 nm to 170 nm, and further preferably from 110 nm to 160 nm. The thickness of the phase difference layer can be adjusted in such a way as to obtain the desired in-plane retardation of a λ / 4 plate. Where the phase difference layer is the liquid crystal alignment solidified layer described above, the thickness thereof is, for example, from 1.0 μm to 2.5 μm. In the present embodiment, the angle formed by the slow axis of the phase difference layer and the absorption axis of the polarizing member is preferably from 40° to 50°, more preferably from 42° to 48°, and further preferably from 44° to 46°. In addition, the phase difference layer preferably exhibits an anomalous dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measuring light.

[0135] In another embodiment where the phase difference layer is a single layer, the phase difference layer can function as a λ / 2 plate. Specifically, the Re(550) of the phase difference layer is preferably from 200 nm to 300 nm, more preferably from 230 nm to 290 nm, and further preferably from 230 nm to 280 nm. The thickness of the phase difference layer can be adjusted in such a way as to obtain the desired in-plane retardation of a λ / 2 plate. Where the phase difference layer is the liquid crystal alignment solidified layer described above, the thickness thereof is, for example, from 2.0 μm to 4.0 μm. In the present embodiment, the angle formed by the slow axis of the phase difference layer and the absorption axis of the polarizing member is preferably from 10° to 20°, more preferably from 12° to 18°, and further preferably from 12° to 16°.

[0136] In one embodiment in which the phase difference layer has a stacked structure, the phase difference layer has a stacked structure in which a first phase difference layer (H layer) and a second phase difference layer (Q layer) are disposed in this order from the polarizing element side. The H layer typically functions as a λ / 2 plate, and the Q layer typically functions as a λ / 4 plate. Specifically, the Re(550) of the H layer is preferably 200 nm to 300 nm, more preferably 220 nm to 290 nm, and further preferably 230 nm to 280 nm; and the Re(550) of the Q layer is preferably 100 nm to 180 nm, more preferably 110 nm to 170 nm, and further preferably 110 nm to 150 nm. The thickness of the H layer can be adjusted in such a manner as to obtain a desired in-plane phase difference of a λ / 2 plate. In the case where the H layer is the liquid crystal alignment solidification layer described above, the thickness thereof is, for example, 2.0 μm to 4.0 μm. The thickness of the Q layer can be adjusted in such a manner as to obtain a desired in-plane phase difference of a λ / 4 plate. In the case where the Q layer is the liquid crystal alignment solidification layer described above, the thickness thereof is, for example, 1.0 μm to 2.5 μm. In the present embodiment, the angle formed by the slow axis of the H layer and the absorption axis of the polarizing element is preferably 10° to 20°, more preferably 12° to 18°, and further preferably 12° to 16°; and the angle formed by the slow axis of the Q layer and the absorption axis of the polarizing element is preferably 70° to 80°, more preferably 72° to 78°, and further preferably 72° to 76°. Note that the order of the H layer and the Q layer can be reversed, and the angle formed by the slow axis of the H layer and the absorption axis of the polarizing element and the angle formed by the slow axis of the Q layer and the absorption axis of the polarizing element can also be reversed. In addition, each layer (e.g., the H layer and the Q layer) can exhibit an anomalous wavelength dispersion characteristic in which the phase difference value increases with the wavelength of the measuring light, can exhibit a normal wavelength dispersion characteristic in which the phase difference value decreases with the wavelength of the measuring light, or can exhibit a flat wavelength dispersion characteristic in which the phase difference value does not substantially change with the wavelength of the measuring light.

[0137] The phase difference layer (at least one layer when having a stacked structure) typically has a refractive index characteristic that exhibits a relationship of nx>ny=nz. Note that "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where they are substantially equal. Thus, there can be cases where ny>nz or ny<nz without impairing the effects of the present application. The Nz coefficient of the phase difference layer is preferably 0.9 to 1.5, and more preferably 0.9 to 1.3.

[0138] As described above, the phase difference layer is preferably a liquid crystal alignment solidified layer. As the above-mentioned liquid crystal compound, for example, a liquid crystal compound having a nematic phase (nematic liquid crystal) can be mentioned. As such a liquid crystal compound, for example, a liquid crystal polymer, a liquid crystal monomer can be used. The mechanism of the expression of the liquid crystallinity of the liquid crystal compound can be lyotropic or thermotropic. The liquid crystal polymer and the liquid crystal monomer can each be used alone or in combination.

[0139] In the case where the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a cross-linkable monomer. This is because, by polymerizing or cross-linking (i.e., solidifying) the liquid crystal monomer, it is possible to fix the alignment state of the liquid crystal monomer. If, for example, the liquid crystal monomers are polymerized or cross-linked with each other after the alignment of the liquid crystal monomers, it is thereby possible to fix the above-mentioned alignment state. Here, by polymerization, a polymer is formed, and by cross-linking, a three-dimensional network structure is formed, which is non-liquid crystalline. Therefore, the phase difference layer formed does not undergo, for example, a transition to a liquid crystal phase, a glass phase, a crystalline phase due to a change in temperature, which is characteristic of a liquid crystalline compound. As a result, the phase difference layer becomes a phase difference layer which is extremely excellent in stability against a change in temperature.

[0140] The temperature range in which the liquid crystal monomer exhibits liquid crystallinity differs depending on the kind thereof. Specifically, the temperature range is preferably 40°C to 120°C, further preferably 50°C to 100°C, most preferably 60°C to 90°C.

[0141] As the above-mentioned liquid crystal monomer, any appropriate liquid crystal monomer can be used. For example, a polymerizable mesogenic compound described in Japanese Patent Application Laid-Open No. 2002-533742 (WO 00 / 37585), EP 358208 (US 5211877), EP 66137 (US 4388453), WO 93 / 22397, EP 0261712, DE 19504224, DE 4408171, and GB 2280445, etc. can be used. As specific examples of such a polymerizable mesogenic compound, for example, LC242 manufactured by BASF Co., E7 manufactured by Merck Co., and LC-Sillicon-CC 3767 manufactured by Wacker-Chem Co. can be mentioned. As the liquid crystal monomer, a nematic liquid crystal monomer is preferred.

[0142] In another embodiment, the phase difference layer has a laminated structure of a first phase difference layer that functions as a λ / 4 plate and a second phase difference layer having a refractive index characteristic showing nz> nx= ny (so-called positive C plate) from the side of the polarizing element. Details of the λ / 4 plate are as described above. In this embodiment, the angle formed by the slow axis of the first phase difference layer and the absorption axis of the polarizing element is preferably 40° to 50°, more preferably 42° to 48°, and further preferably 44° to 46°. In addition, the first phase difference layer preferably shows an abnormal dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measuring light.

[0143] The thickness direction phase difference Rth(550) of the above-described positive C plate is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, further preferably -90 nm to -200 nm, and particularly preferably -100 nm to -180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. The in-plane phase difference Re(550) of the positive C plate is, for example, less than 10 nm.

[0144] The second phase difference layer having a refractive index characteristic of nz> nx= ny can be formed of any appropriate material, and is preferably formed of a thin film containing a liquid crystal material fixed in a vertical alignment. The liquid crystal material (liquid crystal compound) capable of vertical alignment can be a liquid crystal monomer or a liquid crystal polymer. As a specific example of the liquid crystal compound and the method of forming the phase difference layer, the liquid crystal compound and the method of forming the phase difference layer described in Japanese Patent Application Publication No. 2002-333642,

[0020] to

[0028] can be given. In this case, the thickness of the second phase difference layer is preferably 0.5 μm to 5 μm.

[0145] F. Image display device

[0146] The above-described laminate can be applied to an image display device. Therefore, the image display device of the embodiment of the present application is provided with the above-described laminate. As representative examples of the image display device, a liquid crystal display device, an electroluminescence (EL) display device (for example, an organic EL display device, an inorganic EL display device) can be given.

[0147] Figure 2 Taking an organic EL display device as an example, a cross-sectional view schematically showing the outline configuration of an image display panel included in the image display device of one embodiment of the present application is shown. The image display panel (organic EL panel) 200 has an organic panel main body 70 and a laminate 100 disposed on the visually recognizable side thereof. The laminate 100 is disposed in such a manner that the resin layer 20 is on the organic EL panel main body 70 side with respect to the polarizing element 11. Typically, the laminate 100 is attached to the organic EL panel main body 70 with an adhesive layer (not shown).

[0148] The organic EL panel body 70 has a substrate 71 and an upper structure layer 72 including a circuit layer including a thin film transistor (TFT) or the like, an organic light emitting diode (OLED), a sealing film that seals the OLED, and the like. The upper structure layer 72 can include a metal member (for example, an electrode, a sensor, a wiring, a metal layer). For example, in the case where a flexible substrate (for example, a resin substrate) is used as the substrate 71, the obtained organic EL display device can be implemented to be bent, flexed, folded, rolled, or the like. The laminate of the embodiment of the present application can have excellent flexibility and folding durability, and thus can also be suitably applied to such an image display device.

[0149] [Examples]

[0150] Hereinafter, the present application will be specifically described by examples, but the present application is not limited by these examples. The measurement methods of thickness, Tg, and Mw are as follows. Note that "parts" and "%" in the examples and comparative examples are on a weight basis, unless otherwise specified.

[0151] (1) Thickness

[0152] The thickness of 10 μm or less was measured using an interference film thickness meter (Otsuka Electronics Co., Ltd., product name "MCPD-3000"). The thickness of more than 10 μm was measured using a digital micrometer (Anritsu Corporation, product name "KC-351C").

[0153] (2) Glass transition temperature (Tg)

[0154] The midpoint glass transition temperature was calculated from the obtained measurement result, by taking a sample (polymer) of about 5 mg, performing DSC measurement under the following conditions, and the like.

[0155] • Measurement device: TA Instruments, Inc., product name: Q-2000

[0156] • Temperature program: change from 0°C → 150°C → 0°C → 150°C

[0157] • Atmosphere gas: N2(50 mL / minute)

[0158] • Measurement rate: 10°C / minute

[0159] (3) Weight average molecular weight (Mw)

[0160] The measurement was performed by gel permeation chromatography (GPC), and the value converted to a standard polystyrene was obtained.

[0161] • Analysis device: HLC-8120 GPC manufactured by Tosoh Corporation

[0162] • Column: G7000HXL + GMHXL + GMHXL manufactured by Tosoh Corporation

[0163] • Column size: 300 mm x 8.0 mm Total 90 cm

[0164] • Column temperature: 40°C

[0165] • Flow rate: 0.8 ml / min

[0166] • Injection amount: 100 μl

[0167] • Eluent: Tetrahydrofuran

[0168] • Detector: Differential refractometer (RI)

[0169] • Standard sample: Polystyrene

[0170] [Example 1]

[0171] (Production of polarizing member)

[0172] As the thermoplastic resin substrate, a strip-shaped, amorphous copolymerized isophthalic acid polyethylene terephthalate film (thickness: 100 μm) having a water absorption of 0.75% and a Tg of about 75°C was used, and a single surface of the resin substrate was subjected to a corona treatment.

[0173] A PVA-based resin was prepared by mixing 100 parts by weight of polyvinyl alcohol (degree of polymerization: 4200, degree of saponification: 99.2 mol%) and acetyl acetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIME Z410") at a ratio of 9:1, and adding 13 parts by weight of potassium iodide to the mixture, and dissolving the resultant in water.

[0174] The PVA aqueous solution (coating solution) was applied to the corona-treated surface of the resin substrate and dried at 60°C, thereby forming a PVA-based resin layer having a thickness of 13 μm, and a laminate was produced.

[0175] The obtained laminate was subjected to free-end uniaxial stretching in the longitudinal direction (lengthwise direction) at a peripheral speed different between the rollers in an oven at 130°C to 2.4 times (air-assisted stretching treatment).

[0176] Next, the laminate was immersed in an insolubilization bath (boric acid aqueous solution obtained by compounding 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insolubilization treatment).

[0177] Next, the obtained laminate was immersed in an iodine aqueous solution (obtained by mixing iodine and potassium iodide at a weight ratio of 1 : 7 with respect to 100 parts by weight of water) at a liquid temperature of 30°C, and adjusted to a concentration so that the monomer transmittance (Ts) of the finally obtained polarizing member becomes 43.0% or more, and immersed for 60 seconds (dyeing treatment).

[0178] Next, the obtained laminate was immersed in a crosslinking bath (boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40°C, and immersed for 30 seconds (crosslinking treatment).

[0179] Thereafter, the laminate was immersed in a boric acid aqueous solution (boric acid concentration 4.0% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70°C, and uniaxially stretched in the longitudinal direction (lengthwise direction) at a total stretching ratio of 5.5 times between rollers having different circumferential speeds (in-water stretching treatment).

[0180] Thereafter, the laminate was immersed in a washing bath (aqueous solution obtained by mixing 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 20°C (washing treatment).

[0181] Thereafter, the laminate was dried in an oven maintained at 90°C, and contacted with a heating roller made of SUS maintained at a surface temperature of 75°C for about 2 seconds (drying shrinkage treatment). The shrinkage ratio in the width direction of the laminate based on the drying shrinkage treatment was 5.2%.

[0182] Thus, a polarizing member having a thickness of 5 μm was formed on the resin substrate.

[0183] (Production of Polarizing Plate)

[0184] On the surface of the obtained polarizing member (the side opposite to the resin substrate), an HC-COP film was attached as a protective layer with the aid of an ultraviolet-curable adhesive. Specifically, the ultraviolet-curable adhesive was applied so that the thickness after curing becomes 1.0 μm, and attached using a roll press. Thereafter, the adhesive was cured by irradiating UV light from the HC-COP film side. Note that the HC-COP film is a film in which a hard coat (HC) layer (thickness 2 μm) is formed on a cyclic olefin (COP) film (manufactured by Zeon Corporation, trade name "ZF12", thickness 25 μm), and attached so that the COP film is on the side of the polarizing member. Next, the resin substrate was peeled from the polarizing member, and a polarizing plate having a configuration of a protective layer (HC-COP film) / adhesive layer / polarizing member was obtained.

[0185] (Formation of Resin Layer)

[0186] Methyl methacrylate (MMA, manufactured by FUJIFILM Wako Pure Chemical Corporation, trade name: Methyl methacrylate monomer) 99.0 parts by weight, monomer of general formula (1e) 1.0 part by weight, polymerization initiator (manufactured by FUJIFILM Wako Pure Chemical Corporation, trade name: 2,2'-azobis (isobutyronitrile)) 0.2 parts by weight were dissolved in toluene 100 parts by weight. Next, under a nitrogen atmosphere, heating to 70°C was performed and a polymerization reaction was performed for 5.5 hours to obtain copolymer 1 (solid content concentration: 50% by weight). The Tg of copolymer 1 was 105°C and the Mw was 85000.

[0187] As the isocyanate compound, 22.5 parts by solid content of a trimethylolpropane adduct of toluene diisocyanate (manufactured by DKS Corporation, trade name "CORONATE L") and 7.5 parts by solid content of a trimethylolpropane adduct of hexamethylene diisocyanate (manufactured by Mitsui Chemicals, Inc., trade name "TAKENATE D160N") were added to 70 parts by solid content of the obtained copolymer 1 (boron-containing acrylic resin) to obtain a mixture. The mixture was dissolved in a mixed solvent of ethyl acetate / cyclopentanone (70 / 30) 80 parts to obtain a resin solution (20%). The resin solution was applied to the surface of the polarizing member side of the polarizing plate obtained in the above using a wire bar, and the applied film was dried at 60°C for 5 minutes to form a resin layer (thickness 0.4 μm) in the form of a solidified product of the applied film of the organic solvent solution of the resin.

[0188] (Preparation of the adhesive composition)

[0189] The monomer components were mixed in the compounding ratio shown in Table 1 to further obtain an adhesive composition containing a polymerization initiator (manufactured by BASF, trade name "Irgacure 907") 3% by weight. Note that the monomers shown in Table 1 correspond to the trade names described above.

[0190] (Production of the phase difference layer)

[0191] A polymerizable liquid crystal (manufactured by BASF, trade name "Paliocolor LC242", represented by the following formula) 10 g and a photopolymerization initiator (manufactured by BASF, trade name "Irgacure 907") 3 g for the polymerizable liquid crystal compound were dissolved in toluene 40 g to prepare a liquid crystal composition (coating liquid).

[0192]

[0193] The surface of a polyethylene terephthalate (PET) film (thickness 38 μm) was rubbed with a rubbing cloth to perform orientation treatment. The orientation treatment was performed so that the direction of the slow axis of the liquid crystal alignment solidified layer to be formed later would be 15° with respect to the direction of the absorption axis of the polarizing element when viewed from the visual recognition side when the polarizing plate was attached. The liquid crystal coating solution described above was applied to the surface subjected to the orientation treatment using a bar coater, and heat-dried at 90°C for 2 minutes to align the liquid crystal compound. The liquid crystal layer thus formed was irradiated with light of 1 mJ / cm 2 from a metal halide lamp to cure the liquid crystal layer, thereby forming a liquid crystal alignment solidified layer A (H layer) on the PET film. The thickness of the liquid crystal alignment solidified layer A was 2.5 μm, and the in-plane retardation Re(550) was 270 nm. Further, the liquid crystal alignment solidified layer A exhibited a refractive index characteristic of nx>ny=nz.

[0194] The coating thickness was changed, and the orientation treatment was performed so that the direction of the slow axis of the liquid crystal alignment solidified layer to be formed later would be 75° with respect to the direction of the absorption axis of the polarizing element when viewed from the visual recognition side, and otherwise, the same operations as described above were performed to form a liquid crystal alignment solidified layer B (Q layer) on the PET film. The thickness of the liquid crystal alignment solidified layer B was 1.5 μm, and the in-plane retardation Re(550) was 140 nm. Further, the liquid crystal alignment solidified layer B exhibited a refractive index characteristic of nx>ny=nz.

[0195] (Manufacture of the laminate)

[0196] The liquid crystal alignment solidified layer A was transferred to the surface of the resin layer of the polarizing plate on which the resin layer was formed using the adhesive composition described above so that the thickness of the adhesive layer formed after curing would be 1.5 μm. At this time, the transfer (attachment) was performed so that the angle formed by the absorption axis of the polarizing element and the slow axis of the liquid crystal alignment solidified layer A would be 15°. Further, the curing of the adhesive composition was performed by irradiation of ultraviolet rays under a nitrogen atmosphere so that the cumulative light quantity would be 900 mJ / cm 2 .

[0197] Next, the liquid crystal alignment solidified layer B was transferred to the surface of the liquid crystal alignment solidified layer A using an ultraviolet-curable adhesive (thickness after curing 1 μm). At this time, the transfer (attachment) was performed so that the angle formed by the absorption axis of the polarizing element and the slow axis of the liquid crystal alignment solidified layer B would be 75°. Further, the curing of the adhesive composition was performed by irradiation of ultraviolet rays.

[0198] Note that the respective transfers were performed while the roll transport was performed.

[0199] [Example 2 and Example 4]

[0200] The monomer component included in the adhesive composition was changed to that shown in Table 1 below, and otherwise, the same operations as in Example 1 were performed to obtain a laminate.

[0201] [Example 3]

[0202] In the formation of the resin layer, poly(methyl methacrylate) (manufactured by Merck) having a Tg of 110°C and an Mw of 350000 was used instead of the copolymer 1, and otherwise, the same operation as in Example 2 was performed to obtain a laminate.

[0203] [Example 5]

[0204] In the formation of the resin layer, the isocyanate compound was changed as shown in Table 1, and otherwise, the same operation as in Example 4 was performed to obtain a laminate.

[0205] [Comparative Example 1, Comparative Example 2, and Comparative Example 3]

[0206] The monomer component included in the adhesive composition was changed as shown in Table 1 below, and otherwise, the same operation as in Example 1 was performed to obtain a laminate.

[0207] [Comparative Example 4]

[0208] In the formation of the resin layer, poly(methyl methacrylate) (manufactured by Merck) having a Tg of 115°C and an Mw of 1000000 was used instead of the copolymer 1, and otherwise, the same operation as in Example 4 was performed to obtain a laminate.

[0209] [Comparative Example 5]

[0210] In the formation of the resin layer, no isocyanate compound was used, and otherwise, the same operation as in Example 4 was performed to obtain a laminate.

[0211] The following evaluations were performed on the examples and comparative examples. The evaluation results were collected in Table 1 together with various values.

[0212] [Evaluation]

[0213] 1. Cross-sectional observation

[0214] The cross section (magnification: 30000 times) of the obtained laminate was observed using a scanning electron microscope, and it was confirmed whether or not a compatible layer was formed between the resin layer and the adhesive layer.

[0215] [Evaluation Criteria]

[0216] Good: There was a clear interface between the resin layer and the adhesive layer, and no compatible layer was confirmed

[0217] Poor: There was no clear interface between the resin layer and the adhesive layer, and a compatible layer was confirmed

[0218] 2. Peeling property

[0219] After adhering the sample cut out from the obtained laminate to a glass plate in a size of 200 mm in the length direction (stretching direction of the polarizing member) and 15 mm in the width direction with an adhesive, a slit was cut with a cutter near the interface between the resin layer and the adhesive layer, and the peeling force (N / 15 mm) at this time was measured by peeling the polarizing plate in the length direction at a peeling speed of 1000 mm / min in the 90-degree direction using a Tensilon universal testing machine (RTC, manufactured by A&D Company, Limited). Specifically, the peeling force (adhesion) of the adhesive layer (laminated portion of the adhesive layer and the phase difference layer) to the resin layer was measured. Note that the measurement was performed in an environment of 23°C and 50% RH.

[0220] [Table 1]

[0221]

[0222] In each of the examples, excellent adhesion was confirmed. As shown in Table 1, in each of the examples, no compatible layer between the resin layer and the adhesive layer was confirmed. In Comparative Example 1, a compatible layer was confirmed as shown in Table 1. In Comparative Example 2, no compatible layer was confirmed as shown in Table 1. In Comparative Example 3, a compatible layer was confirmed as shown in Table 1. Figure 3 Figure 3 Figure 4 Figure 4

[0223] Industrial Applicability

[0224] The laminate of the embodiment of the present application can be used, for example, for an image display device. As the image display device, a liquid crystal display device, an organic EL display device, and an inorganic EL display device can be exemplified.​​​​

Claims

1. A laminate having: a polarizing plate including a polarizing member, a functional layer, a resin layer disposed between the polarizing plate and the functional layer, and an adhesive layer, the resin layer and the adhesive layer are disposed in contact with each other, the resin layer is disposed in contact with the polarizing member, the resin layer is a solidified or thermally cured product of a coated film of an organic solvent solution of a resin, and includes: a resin having a glass transition temperature of 85°C or higher and a weight average molecular weight Mw of 50,000 or more and less than 500,000, and an isocyanate compound including at least one selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and derivatives thereof, and at least one of hexamethylene diisocyanate or a derivative thereof, wherein the amount of the hexamethylene diisocyanate and the derivative thereof is 10 to 40 parts by weight with respect to 100 parts by weight of the isocyanate compound, the content of the resin in the resin layer is 50 to 90% by weight, and the content of the isocyanate compound in the resin layer is 10 to 50% by weight, the thickness of the resin layer is 1 μm or less, the adhesive layer is composed of a cured product layer of an adhesive composition, and the octanol / water partition coefficient logPow calculated by weighted average of the mole fraction of a monomer component included in the adhesive composition is 1.5 or more and 4.0 or less.

2. The laminate according to claim 1, wherein the content of a monomer component having an octanol / water partition coefficient logPow of 0.0 or less is 30 parts by weight or less with respect to 100 parts by weight of the monomer component included in the adhesive composition.

3. The laminate according to claim 1, wherein the thickness of the adhesive layer is 3 μm or less.

4. The laminate according to claim 1, wherein the functional layer is a phase difference layer.

5. An image display device provided with the laminate according to any one of claims 1 to 4.

6. A method for producing a laminate, comprising: forming a resin layer by applying an organic solvent solution including a resin and an isocyanate compound to a polarizing plate including a polarizing member, adhering a functional layer to the resin layer with an adhesive composition, the resin has a glass transition temperature of 85°C or higher and a weight average molecular weight Mw of 50,000 or more and less than 500,000, the isocyanate compound includes at least one selected from the group consisting of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and derivatives thereof, and at least one of hexamethylene diisocyanate or a derivative thereof, wherein the amount of the hexamethylene diisocyanate and the derivative thereof is 10 to 40 parts by weight with respect to 100 parts by weight of the isocyanate compound, the content of the resin in the resin layer is 50 to 90% by weight, and the content of the isocyanate compound in the resin layer is 10 to 50% by weight, the thickness of the resin layer is 1 μm or less, the octanol / water partition coefficient logPow calculated by weighted average of the mole fraction of a monomer component included in the adhesive composition is 1.5 or more and 4.0 or less.

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