Polarizing plate with adhesive layer and display device

Abstract

To provide a polarizing plate with an adhesive layer and a display device that are less likely to curl.SOLUTION: A polarizing plate with an adhesive layer comprises: a polarizing plate having a protective film, a polarizer, a positive A plate, and a positive C plate in this order; and an adhesive layer which is arranged on the positive C plate side of the polarizing plate. The positive A plate is a layer that is obtained by hardening a polymerizable liquid crystal compound, and the thickness of the positive C plate is 20.0 - 70.0 μm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polarizing plate with an adhesive layer and a display device.

Background Art

[0002] An optically anisotropic layer formed using a liquid crystal compound is applied in various fields such as the display field. For example, Patent Document 1 discloses a method for manufacturing a polarizing plate including a polarizer and an optically anisotropic layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As one form of use of a polarizing plate, it is desired to dispose an adhesive layer on one surface of the polarizing plate and use it as a polarizing plate with an adhesive layer. When the inventors of the present invention disposed an adhesive layer on one surface of a polarizing plate as disclosed in Patent Document 1 to produce a polarizing plate with an adhesive layer, it was found that the polarizing plate with an adhesive layer curled, making it difficult to adhere to an adherend.

[0005] In view of the above circumstances, an object of the present invention is to provide a polarizing plate with an adhesive layer in which the generation of curl is suppressed. Another object of the present invention is to provide a display device.

Means for Solving the Problems

[0006] As a result of intensive studies to solve the above problems, the inventors of the present invention completed the present invention having the following configuration.

[0007] The inventors have found that the above problems can be solved by the following configuration.

[0008] (1) A polarizing plate having a protective film, a polarizer, a positive A plate, and a positive C plate in this order, and an adhesive layer disposed on the positive C plate side of the polarizing plate, the polarizing plate with an adhesive layer having the positive A plate being a layer obtained by curing a polymerizable liquid crystal compound, the polarizing plate with an adhesive layer, wherein the thickness of the positive C plate is 20.0 to 70.0 μm. (2) The polarizing plate with an adhesive layer according to (1), wherein the polarizing plate with an adhesive layer is bonded to a glass substrate via an adhesive, and when a 100 - grid cross - cut test is performed on the bonded polarizing plate with an adhesive layer, the number of peeled grids is 50 or less. (3) The polarizing plate with an adhesive layer according to (1) or (2), wherein the retardation in the thickness direction of the positive C plate at a wavelength of 550 nm is - 100 to - 30 nm. (4) The polarizing plate with an adhesive layer according to any one of (1) to (3), wherein the positive C plate contains a polymer film. (5) The polarizing plate with an adhesive layer according to (4), wherein the polymer film is a cellulose acylate film. (6) The polarizing plate with an adhesive layer according to (4) or (5), wherein the in - plane retardation of the polymer film at a wavelength of 550 nm is 10 nm or less. (7) The polarizing plate with an adhesive layer according to any one of (4) to (6), wherein the retardation in the thickness direction of the polymer film at a wavelength of 550 nm is - 100 to 30 nm. (8) The polarizing plate with an adhesive layer according to any one of (4) to (7), wherein the positive C plate contains a vertically aligned liquid crystal layer and a polymer film. (9) The polarizing plate with an adhesive layer according to (8), wherein the vertically aligned liquid crystal layer contains an aggregate unevenly distributed on the polymer film side. (10) The vertically aligned liquid crystal layer is a layer formed using a composition containing a liquid crystal compound and a crosslinkable polymer, and the crosslinkable polymer has a hydroxyl group. The polarizing plate with an adhesive layer according to (8) or (9). (11) The vertically aligned liquid crystal layer contains a photo-isomerizable compound on the surface opposite to the polymer film side. The polarizing plate with an adhesive layer according to any one of (8) to (10). (12) The angle formed by the absorption axis of the polarizer and the in-plane slow axis of the positive A plate is 45 ± 10°, The in-plane retardation of the positive A plate at a wavelength of 550 nm is 120 to 170 nm. The polarizing plate with an adhesive layer according to any one of (1) to (11). (13) The polarizer and the positive A plate are laminated via a polyvinyl alcohol-based adhesive. The polarizing plate with an adhesive layer according to any one of (1) to (12). (14) The positive A plate is a layer obtained by curing a composition containing a polymerizable liquid crystal compound and a polymer having a group represented by the following formula (1). The polarizing plate with an adhesive layer according to any one of (1) to (13). (15) The polarizer and the positive A plate are laminated via an adhesive layer formed by curing an ultraviolet curable adhesive. The polarizing plate with an adhesive layer according to any one of (1) to (12). (16) The polymer film includes a region A containing a liquid crystal-derived component contained in the vertically aligned liquid crystal layer, and the thickness of the region A is 20 to 200 nm. The polarizing plate with an adhesive layer according to any one of (8) to (14). (17) A display device having the polarizing plate with an adhesive layer according to any one of (1) to (16).

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a polarizing plate with an adhesive layer in which the generation of curl is suppressed. Further, according to the present invention, a display device can also be provided.

Brief Description of the Drawings

[0010]

Figure 1

Embodiments for Carrying Out the Invention

[0011] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments and specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0012] In this specification, the "absorption axis" means the polarization direction in which the absorbance is maximum in the plane when linearly polarized light is incident. Also, the "in-plane slow axis" means the direction in which the refractive index is maximum in the plane.

[0013] Also, in this specification, Re(λ) and Rth(λ) represent the in-plane retardation and the thickness-direction retardation at wavelength λ, respectively. When not otherwise specified, the wavelength λ is 550 nm. In the present invention, Re(λ) and Rth(λ) are values measured at wavelength λ with AxoScan (manufactured by Axometrics). By inputting the average refractive index ((nx + ny + nz) / 3) and the film thickness (d) with AxoScan, In-plane slow axis direction (°) Re(λ) = R0(λ) Rth(λ) = ((nx + ny) / 2 - nz) × d are calculated. Note that R0(λ) is a numerical value calculated by AxoScan and displayed, but it means Re(λ).

[0014] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) with a sodium lamp (λ = 589 nm) as the light source. When measuring the wavelength dependence, it can be measured in combination with an interference filter using a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.). Also, the values in the Polymer Handbook (JOHN WILEY&SONS,INC) and various optical film catalogs can be used. The values of the average refractive index of main optical films are exemplified below: cellulose acetate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0015] In this specification, the A plate and the C plate are defined as follows. There are two types of A plates: a positive A plate (plus A plate) and a negative A plate (minus A plate). When the refractive index in the in-plane slow axis direction of the film (the direction in which the refractive index in the plane is maximum) is nx, the refractive index in the direction orthogonal to the in-plane slow axis in the plane is ny, and the refractive index in the thickness direction is nz, the positive A plate satisfies the relationship of formula (A1), and the negative A plate satisfies the relationship of formula (A2). Note that the positive A plate shows a positive value for Rth, and the negative A plate shows a negative value for Rth. Formula (A1) nx>ny≒nz Formula (A2) ny<nx≒nz Note that the above "≒" includes not only the case where both are exactly the same but also the case where both are substantially the same. "Substantially the same" means that, for example, (ny - nz)×d (where d is the thickness of the film) is in the range of -10 to 10 nm, preferably -5 to 5 nm, is also included in "ny≒nz", and (nx - nz)×d is in the range of -10 to 10 nm, preferably -5 to 5 nm, is also included in "nx≒nz". There are two types of C plates: a positive C plate and a negative C plate. The positive C plate satisfies the relationship of formula (C1), and the negative C plate satisfies the relationship of formula (C2). Note that the positive C plate shows a negative value for Rth, and the negative C plate shows a positive value for Rth. Formula (C1) nz>nx≒ny Formula (C2) nz<nx≒ny Note that the above “≒” includes not only the case where both are exactly the same but also the case where both are substantially the same. “Substantially the same” means that, for example, (nx - ny)×d (where d is the thickness of the film) is in the range of 0 to 10 nm, preferably 0 to 5 nm, which is also included in “nx≒ny”.

[0016] A characteristic point of the polarizing plate with an adhesive layer of the present invention is that a positive C plate with a predetermined thickness is used. As a factor that easily causes curling in a conventional polarizing plate with an adhesive layer, it can be mentioned that the positive A plate included in the polarizing plate with an adhesive layer is a layer obtained by curing a polymerizable liquid crystal compound. Since the positive A plate is a layer obtained by curing a polymerizable liquid crystal compound, stress due to curing shrinkage during polymerization remains, and as a result, the entire polarizing plate with an adhesive layer is considered to be easily curled. Therefore, in the present invention, curling is suppressed by adjusting the thickness of the positive C plate within a predetermined range.

[0017] FIG. 1 shows an example of the polarizing plate with an adhesive layer of the present invention. As shown in FIG. 1, the polarizing plate 10 with an adhesive layer has a polarizing plate 12 and an adhesive layer 22 in this order. The polarizing plate 12 has a protective film 14, a polarizer 16, a positive A plate 18, and a positive C plate 20 in this order. As shown in FIG. 1, the adhesive layer 22 is disposed on the positive C plate 20 side in the polarizing plate 12. More specifically, the adhesive layer 22 is disposed on the surface of the polarizing plate 12 on the positive C plate 20 side. Further, the positive C plate 20 has a vertically aligned liquid crystal layer 24 and a polymer film 26. In FIG. 1, each layer is directly adjacent to another layer, but as will be described later, they may be laminated via other layers (for example, an adhesion layer). Hereinafter, each member included in the polarizing plate 10 with an adhesive layer will be described in detail.

[0018] <Protective film> The protective film is a film that protects the polarizer. The configuration of the protective film is not particularly limited. For example, it may be a transparent support or a hard coat layer, or a laminate of a transparent support and a hard coat layer. In this specification, "transparent" means that the transmittance of visible light is 60% or more, preferably 80% or more, and more preferably 90% or more. The upper limit is not particularly limited, but it is often less than 100%.

[0019] Examples of the transparent support include known transparent supports (preferably, transparent resin supports). Examples of the material for forming the transparent support include cellulose-based resins typified by triacetyl cellulose (hereinafter, also referred to as cellulose acylate), norbornene-based resins (Zeonex, Zeonor manufactured by Nippon Zeon Co., Ltd., Arton manufactured by JSR Corporation, etc.), acrylic resins, polyester-based resins, and polystyrene-based resins. Among them, cellulose-based resins or norbornene-based resins are preferable, and cellulose-based resins are more preferable. Note that the norbornene-based resin refers to a resin having a norbornene skeleton. More specifically, cycloolefin polymer (COP) and cycloolefin copolymer (COC) can be mentioned. Further, as the hard coat layer, a known layer can be used. For example, a layer obtained by polymerizing and curing a polyfunctional monomer may be used.

[0020] The thickness of the protective film is not particularly limited, but from the viewpoint of being able to reduce the thickness of the polarizing plate, 40 μm or less is preferable, and 25 μm or less is more preferable. The lower limit is not particularly limited, but it is often 10 μm or more.

[0021] <Polarizer> The polarizer may be a member having a function of converting natural light into specific linearly polarized light. For example, an absorption type polarizer can be mentioned. The type of the polarizer is not particularly limited, and commonly used polarizers can be used. For example, iodine-based polarizers, dye-based polarizers using dichroic substances, and polyene-based polarizers can be mentioned. Iodine-based polarizers and dye-based polarizers are generally produced by adsorbing iodine or dichroic dyes on polyvinyl alcohol and stretching them.

[0022] It is also preferable that the polarizer is a polarizer formed using a composition containing a dichroic substance and a liquid crystal compound having a polymerizable group. The dichroic substance is not particularly limited, and examples include visible light absorbing substances (dichroic dyes), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet light absorbing substances, infrared light absorbing substances, non-linear optical substances, carbon nanotubes, and inorganic substances (for example, quantum rods). Conventionally known dichroic substances (dichroic dyes) can be used.

[0023] The single transmittance for visual sensitivity correction of the polarizer is not particularly limited, and from the viewpoint that the effects of the present invention are more excellent, 42% or more is preferable, and 43% or more is more preferable. The upper limit is not particularly limited, and 48% or less is preferable. Note that the single transmittance for visual sensitivity correction is calculated by the following method. Regarding the polarizer, using a spectrophotometer with an integrating sphere ["V7100" manufactured by JASCO Corporation], the transmittance (T1) in the absorption axis direction and the transmittance (T2) in the direction perpendicular to the absorption axis in the wavelength range of 380 to 780 nm are measured, and based on the following formula, the single transmittance at each wavelength is calculated. Single transmittance (%) = (T1 + T2) / 2 Regarding the obtained single transmittance, perform visual sensitivity correction according to the 2-degree field of view (C light source) of JIS Z 8701:1999 "Color Display Method - XYZ Color System and X10Y10Z10 Color System" to obtain the visually sensitivity-corrected single transmittance.

[0024] The thickness of the polarizer is not particularly limited, but from the point that the thickness of the polarizing plate can be reduced, 40 μm or less is preferable, and 25 μm or less is more preferable. The lower limit is not particularly limited, but it is often 5 μm or more.

[0025] <Positive A plate> The definition of the positive A plate is as described above. Re(550), which is the in-plane retardation of the positive A plate at a wavelength of 550 nm, is not particularly limited, but in terms of the polarizing plate of the present invention being more excellent as a circular polarizing plate, it is preferably 100 to 180 nm, more preferably 120 to 170 nm, and even more preferably 130 to 150 nm.

[0026] The positive A plate may exhibit normal wavelength dispersibility (the property that the in-plane retardation decreases as the measurement wavelength increases), or reverse wavelength dispersibility (the property that the in-plane retardation increases as the measurement wavelength increases). The above normal wavelength dispersibility and reverse wavelength dispersibility are preferably exhibited in the visible light region.

[0027] The positive A plate is a layer obtained by curing a polymerizable liquid crystal compound. Among them, in terms of the polarizing plate of the present invention being more excellent as a circular polarizing plate, a layer obtained by curing a horizontally aligned polymerizable rod-shaped liquid crystal compound is preferable. Note that the state where the polymerizable rod-shaped liquid crystal compound is horizontally aligned means that the major axis of the polymerizable rod-shaped liquid crystal compound is parallel to the main plane of the positive A plate. It is not required to be exactly parallel, and the angle formed by the major axis of the polymerizable rod-shaped liquid crystal compound and the main plane of the positive A plate is preferably in the range of 0 ± 20°, and preferably within the range of 0 ± 10°.

[0028] The polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable group. As the polymerizable liquid crystal compound, known compounds can be used. Examples of the polymerizable rod-like liquid crystal compound include compounds described in claim 1 of JP-A No. 11-513019 and in paragraphs 0026 to 0098 of JP-A No. 2005-289980. In the present specification, the type of polymerizable group is not particularly limited, and a functional group capable of undergoing an addition polymerization reaction is preferred, a polymerizable ethylenically unsaturated group or a ring-polymerizable group is more preferred, and a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group is even more preferred.

[0029] The positive A plate is preferably a layer formed by fixing a polymerizable rod-shaped liquid crystal compound by polymerization, and more preferably a layer formed by fixing a horizontally aligned polymerizable rod-shaped liquid crystal compound by polymerization. In this specification, the "fixed" state refers to a state in which the alignment of the liquid crystal compound is maintained. Specifically, it is preferable that the layer has no fluidity and the alignment is not changed by an external field or external force in a temperature range of usually 0 to 50°C, or under more severe conditions, −30 to 70°C, and that the fixed alignment can be stably maintained.

[0030] The angle between the in-plane slow axis of the positive A plate and the absorption axis of the polarizer is not particularly limited, but is preferably within the range of 45±10° (35 to 55°) in order to provide a polarizing plate of the present invention with superior properties as a circular polarizing plate.

[0031] The thickness of the positive A plate is not particularly limited, but is preferably 10 μm or less, more preferably 0.1 to 5.0 μm. The thickness of the positive A plate refers to the average thickness of the positive A plate. The average thickness is determined by measuring the thickness at any five or more points on the positive A plate and calculating the arithmetic average. The thickness can be measured using, for example, a reflection spectroscopic film thickness meter FE3000.

[0032] The positive A plate is preferably a layer obtained by curing a composition containing a polymerizable liquid crystal compound and a polymer having a group represented by the formula (1). The polymerizable liquid crystal compound is as described above.

[0033] By using a polymer having a group represented by the formula (1), the adhesion between the positive A plate and the water-based adhesive disposed adjacent to the positive A plate is improved. Formula (1) *-B-(OR x1 )2 R x1 each independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and two Rs x1 may be linked to each other via a linking group consisting of an alkylene linking group, an arylene linking group, or a combination thereof.

[0034] Examples of the substituted or unsubstituted aliphatic hydrocarbon group include an alkyl group, an alkenyl group, or an alkynyl group which may have a substituent. Examples of the substituted or unsubstituted aryl group include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthylenyl group, a fluorenyl group, and a pyrenyl group. Examples of the substituted or unsubstituted heteroaryl group include those obtained by removing one hydrogen atom from a heteroaromatic ring containing one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom to form a heteroaryl group.

[0035] The above polymer preferably contains a repeating unit having a group represented by the formula (1). Examples of the repeating unit having a group represented by the formula (1) include a repeating unit represented by the formula (X).

[0036] [Chemical formula]

[0037] R x1 The definition of is as described above. R x2 and R x3 each independently represents a hydrogen atom or an alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but 1 to 18 is preferred. The alkyl group may have any of a straight-chain, branched-chain, and cyclic structure.

[0038] R x4 represents a hydrogen atom or a substituent. Substituents include hydroxy groups, alkyl groups, alkenyl groups and aryl groups.

[0039] L x represents a divalent linking group. The divalent linking group is not particularly limited, and may be an alkylene group (preferably an alkylene group having 1 to 20 carbon atoms), an arylene group, -O-, -S-, -CO-, -SO-, -SO2-, or -NR a -, or a divalent linking group formed by combining a plurality of these. a represents a hydrogen atom or an alkyl group. Among them, the divalent linking group is -alkylene group-O- (arylene group-CO-O) nx -arylene group- is preferred. nx represents an integer of 0 to 2.

[0040] The content of the repeating unit having the group represented by formula (1) is preferably 5 to 30 mass % based on the total repeating units contained in the polymer.

[0041] The polymer may contain repeating units other than the repeating unit having the group represented by formula (1). For example, the polymer may contain a repeat unit having a group represented by formula (2).

[0042] [ka]

[0043] R y1 ~R y3 each independently represents an alkyl group, an alkenyl group, an aryl group or an alkylene aryl group. Examples of the alkyl group include linear alkyl groups having 1 to 18 carbon atoms, branched alkyl groups having 3 to 18 carbon atoms, and cyclic alkyl groups. Examples of the alkenyl group include alkenyl groups having 2 to 12 carbon atoms. Examples of the aryl group include aryl groups having 6 to 12 carbon atoms. Specifically, a phenyl group, an α-methylphenyl group, and a naphthyl group are included. Examples of the alkylene aryl group include alkylene aryl groups having 7 to 30 carbon atoms.

[0044] The above polymer preferably contains a repeating unit having a group represented by formula (2). Examples of the repeating unit having a group represented by formula (2) include a repeating unit represented by formula (Y).

[0045]

Chemical formula

[0046] R y1 ~R y3 are as defined above. R y4 and R y5 each independently represents an alkyl group. The number of carbon atoms of the alkyl group is not particularly limited, and 1 to 18 is preferred. The alkyl group may have any of linear, branched, and cyclic structures.

[0047] R y6 represents a hydrogen atom or a substituent. Examples of the substituent include a hydroxy group, an alkyl group, an alkenyl group, and an aryl group.

[0048] Ly1 represents a single bond or an alkylene group having 1 to 6 carbon atoms L y2 represents an ny+1-valent linking group having no fluorine atom. L y2 Examples of the ny+1-valent linking group having no fluorine atom represented by L include an ny+1-valent hydrocarbon group having 1 to 15 carbon atoms which may have substituents other than fluorine atoms, and a hydrocarbon group in which a part of the carbon atoms constituting the hydrocarbon group may be substituted with heteroatoms. For example, among -CH2- constituting a part of the ny+1-valent hydrocarbon group, one or two or more non-adjacent -CH2- may each independently be substituted with -O-, -CO-, -S-, or -N(Q)-. Here, Q represents a hydrogen atom or a substituent, and as the substituent represented by Q, an alkyl group is preferable, a linear alkyl group having 1 to 4 carbon atoms is more preferable, and a methyl group or an ethyl group is even more preferable. Further, >C< (carbon atom) may be substituted with >Si< (silicon atom).

[0049] ny represents an integer of 2 or more. ny is preferably an integer of 2 to 8, more preferably an integer of 3 to 6, and even more preferably an integer of 3 to 5.

[0050] The content of the repeating unit having the group represented by the formula (2) is preferably 25 to 65% by mass based on all the repeating units contained in the polymer.

[0051] The above polymer preferably contains a repeating unit having a polymerizable group. The polymerizable group is as described above. Examples of the repeating unit having a polymerizable group include the repeating unit represented by the formula (Z).

[0052]

Chemical formula

[0053] R z1 and R z2 each independently represent a hydrogen atom or an alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, and 1 to 18 is preferred. The alkyl group may have any of linear, branched, and cyclic structures.

[0054] R z3 represents a hydrogen atom or a substituent. Examples of the substituent include a hydroxy group, an alkyl group, an alkenyl group, and an aryl group.

[0055] L z represents a divalent linking group. The divalent linking group is not particularly limited, and examples thereof include an alkylene group (preferably an alkylene group having 1 to 20 carbon atoms), an arylene group, -O-, -S-, -CO-, -SO-, -SO2-, -NR a -, or a divalent linking group formed by combining a plurality of these. R a represents a hydrogen atom or an alkyl group.

[0056] R z4 represents a polymerizable group.

[0057] The content of the repeating unit having a polymerizable group is preferably 5 to 40% by mass, more preferably 80 to 99% by mass, based on all the repeating units contained in the polymer.

[0058] The weight average molecular weight of the polymer having the group represented by the formula (1) is preferably 5000 to 200000.

[0059] The content of the polymerizable liquid crystal compound in the composition is not particularly limited, and is preferably 50 to 99.9% by mass, more preferably 80 to 99% by mass, based on all the solid components in the composition. The content of the above polymer in the composition is not particularly limited, and is preferably 0.001 to 5.0% by mass, more preferably 0.01 to 2.0% by mass, based on all the solid components in the composition. The solid content means the components excluding the solvent in the composition. Even if the property thereof is liquid, it is regarded as the solid content.

[0060] <Positive C plate> The definition of the positive C plate is as described above. The retardation Rth(550) in the thickness direction of the positive C plate at a wavelength of 550 nm is not particularly limited, but in terms of the polarizing plate of the present invention being more excellent as a circular polarizing plate, -120 to -10 nm is preferable, and -100 to -30 nm is more preferable.

[0061] The configuration of the positive C plate is not particularly limited, and examples include a vertically aligned liquid crystal layer (a layer formed by fixing a vertically aligned rod-shaped liquid crystal compound) and a polymer film. In terms of the effects of the present invention being more excellent, it is preferably a laminate of a vertically aligned liquid crystal layer and a polymer film. That is, the positive C plate preferably includes a vertically aligned liquid crystal layer and a polymer film. When the positive C plate includes a vertically aligned liquid crystal layer and a polymer film, it may further include an optically isotropic layer (for example, an adhesive layer, etc.) between the vertically aligned liquid crystal layer and the polymer film. The optically isotropic layer means a layer in which the in-plane retardation Re at a wavelength of 550 nm is 10 nm or less and the absolute value of the retardation Rth in the thickness direction at a wavelength of 550 nm is 10 nm or less. As described above, when the positive C plate includes an optically isotropic layer between the vertically aligned liquid crystal layer and the polymer film, the thickness of the optically isotropic layer is also included in the thickness of the positive C plate. Also, from the point that the adhesion between the vertically aligned liquid crystal layer and the polymer film is more excellent, it is preferable that the vertically aligned liquid crystal layer and the polymer film are in direct contact. Also, the state in which the rod-shaped liquid crystal compound is vertically aligned means that the long axis of the rod-shaped liquid crystal compound is parallel to the thickness direction of the positive C plate. It should be noted that it is not required to be exactly parallel, and the angle formed by the long axis of the rod-shaped liquid crystal compound and the thickness direction of the first positive C plate is preferably in the range of 0 ± 20°, and preferably within the range of 0 ± 10°. Also, the vertically aligned liquid crystal layer is preferably a layer formed by fixing a vertically aligned polymerizable rod-shaped liquid crystal compound by polymerization.

[0062] When the positive C plate's vertically aligned liquid crystal layer and the polymer film are in direct contact, the polymer film preferably contains a region (referred to as region A) containing components derived from the liquid crystal contained in the vertically aligned liquid crystal layer. From the viewpoints of adhesion and the alignment property of the vertically aligned liquid crystal layer, the thickness of region A is preferably 20 to 200 nm. In region A, it is preferable that vertically aligned liquid crystal compounds exist. As a method for controlling the thickness of region A, there are methods such as controlling by adjusting the solvent type and solid content concentration of the composition for forming the vertically aligned liquid crystal layer, controlling by containing a crosslinkable polymer or a vertical alignment agent described later in the vertically aligned liquid crystal layer, and controlling by the drying and heating conditions of the vertically aligned liquid crystal layer, etc. Whether the polymer film contains region A containing components derived from the liquid crystal contained in the vertically aligned liquid crystal layer can be confirmed by performing time-of-flight secondary ion mass spectrometry while irradiating an ion beam from the surface on the vertically aligned liquid crystal layer side toward the polymer film side of the vertically aligned liquid crystal layer and measuring the secondary ion intensity of the components derived from the liquid crystal of the vertically aligned liquid crystal layer. When the secondary ion intensity I of the components derived from the liquid crystal of the vertically aligned liquid crystal layer in the polymer film satisfies the following formula (I-1), and whether there is a thickness of the region including the surface on the vertically aligned liquid crystal layer side of the polymer film. Ic in the formula indicates the average value of the secondary ion intensity of the components derived from the liquid crystal of the vertically aligned liquid crystal layer in the central region from the surface on the polymer film side of the vertically aligned liquid crystal layer to the depth position corresponding to 40% to 60% of the total thickness of the vertically aligned liquid crystal layer. 0.05 ≦ I / Ic (I-1)

[0063] As the rod-shaped liquid crystal compound, known compounds can be used. As the rod-shaped liquid crystal compound, for example, the rod-shaped liquid crystal compounds exemplified with the positive A plate can be mentioned.

[0064] The liquid crystal compound (preferably a rod-shaped liquid crystal compound) may have a polymerizable group. The types of polymerizable groups that the liquid crystal compound may have are as described above.

[0065] The thickness of the positive C plate is 20.0 to 70.0 μm, preferably 25.0 to 60.0 μm, and more preferably 30.0 to 50.0 μm in terms of more suppressing the occurrence of curl. Note that the thickness of the positive C plate refers to the average thickness of the positive C plate. The above average thickness is obtained by measuring the thicknesses of five or more arbitrary points on the positive C plate and calculating their arithmetic mean. The thickness measurement can be carried out, for example, using a reflection spectroscopic film thickness meter FE3000.

[0066] As one of the preferred embodiments of the positive C plate, an embodiment including a polymer film is preferred, and an embodiment including a vertically aligned liquid crystal layer and a polymer film is more preferred. The resin constituting the polymer film is not particularly limited, and known resins can be mentioned. More specifically, examples of the resin include cellulose-based resins (hereinafter also referred to as cellulose acrylates) typified by triacetyl cellulose, norbornene-based resins (Zeonex, Zeonor manufactured by Nippon Zeon Co., Ltd., Arton manufactured by JSR Corporation, etc.), acrylic-based resins, polyester-based resins, and polystyrene-based resins. Among them, as the polymer film, a film containing a cellulose-based resin is preferred, and a cellulose acrylate film is more preferred.

[0067] The retardation in the thickness direction of the polymer film at a wavelength of 550 nm is not particularly limited, and is preferably -120 to 30 nm, and more preferably -100 to 30 nm in terms of the polarizing plate of the present invention being more excellent as a circular polarizing plate. The in-plane retardation of the polymer film at a wavelength of 550 nm is not particularly limited, and is preferably 10 nm or less in terms of the polarizing plate of the present invention being more excellent as a circular polarizing plate. The lower limit is not particularly limited and is 0 nm.

[0068] The thickness of the polymer film is not particularly limited, and is preferably 15.0 to 65.0 μm, more preferably 25.0 to 60.0 μm, and particularly preferably 30.0 to 50.0 μm in terms of more suppressing the occurrence of curl. Note that the thickness of the polymer film refers to the average thickness of the polymer film. The above average thickness is obtained by measuring the thicknesses of five or more arbitrary points on the polymer film and calculating their arithmetic mean.

[0069] As described above, the vertically aligned liquid crystal layer is a layer formed by fixing a vertically aligned rod-shaped liquid crystal compound. When the positive C plate includes a vertically aligned liquid crystal layer and a polymer film, in terms of the better adhesion between the vertically aligned liquid crystal layer and the polymer film, it is preferable that the vertically aligned liquid crystal layer contains crosslinked products unevenly distributed on the polymer film side. Examples of the crosslinked products include crosslinked products formed by crosslinking a polymer having a crosslinkable group, which will be described later. Examples of the crosslinkable group include the polymerizable groups described above. Note that the uneven distribution of the crosslinked products on the polymer film side means that when the vertically aligned liquid crystal layer is divided into two along the thickness direction, the content of the crosslinked products in the divided region on the polymer film side is higher than that in the divided region on the side opposite to the polymer film side.

[0070] One of the preferred embodiments of the vertically aligned liquid crystal layer is a layer formed using a composition containing a liquid crystal compound and a crosslinkable polymer, and an embodiment in which the crosslinkable polymer has a hydroxyl group can be mentioned. Since the crosslinkable polymer has a hydroxyl group, it is easy for the polymer having a crosslinkable group to be unevenly distributed on the side of the polymer film (especially, the cellulose acylate film), and as a result, the crosslinked products formed by crosslinking the crosslinkable polymer are likely to be unevenly distributed on the polymer film side as described above. Examples of the liquid crystal compound contained in the composition include the liquid crystal compounds described above.

[0071] The crosslinkable polymer preferably contains a repeating unit having a crosslinkable group. As described above, the crosslinkable group is preferably a polymerizable group. That is, the crosslinkable polymer preferably contains a repeating unit having a polymerizable group. Examples of the repeating unit having a polymerizable group include the repeating unit represented by the above formula (Z).

[0072] From the viewpoint of causing the crosslinked product to be unevenly distributed on the polymer film side, it is preferable that the crosslinkable polymer does not have a fluorine atom, a silicon atom, or a photo-aligning group (for example, a cinnamoyl group or an azo group). That is, it is preferable that the crosslinked product formed by crosslinking the crosslinkable polymer does not have a fluorine atom, a silicon atom, and a photo-aligning group.

[0073] The content of the repeating unit having a crosslinkable group is preferably 50 to 99% by mass based on all the repeating units contained in the crosslinkable polymer.

[0074] The crosslinkable polymer preferably contains a repeating unit having a hydroxyl group. The number of hydroxyl groups contained in the repeating unit is not particularly limited, and is preferably 1 to 3, more preferably 1 or 2. The content of the repeating unit having a hydroxyl group is preferably 1 to 30% by mass based on all the repeating units contained in the crosslinkable polymer.

[0075] The crosslinkable polymer may have a repeating unit different from the above-described repeating unit. The content of the other repeating unit is preferably 1 to 30% by mass based on all the repeating units contained in the crosslinkable polymer.

[0076] The weight average molecular weight of the crosslinkable polymer is preferably 5000 to 200000.

[0077] Specific examples of the crosslinkable polymer include, but are not limited to, the following structures. In the repeating unit, a to c described represent the content (% by mass) of each repeating unit with respect to all the repeating units.

[0078]

Chemical formula

[0079] The content of the liquid crystal compound in the composition is not particularly limited, and is preferably 50 to 99% by mass, more preferably 80 to 95% by mass, based on the total solid content in the composition. The content of the crosslinkable polymer in the composition is not particularly limited, and is preferably 0.1 to 20% by mass, more preferably 1 to 5% by mass, based on the total solid content in the composition. The solid content means the components excluding the solvent in the composition. Even if its property is liquid, it is regarded as the solid content.

[0080] The vertically aligned liquid crystal layer preferably contains an alignment control agent. The alignment control agent may be any alignment control agent having a function of vertically aligning, and known materials can be selected and used. When the above-mentioned crosslinkable polymer containing a hydroxyl group is used in the composition for forming the vertically aligned liquid crystal layer, it is preferable to use an onium salt compound as the alignment control agent in terms of higher alignment property.

[0081] The vertically aligned liquid crystal layer preferably contains a photo-isomerizable compound on the surface opposite to the polymer film side. As will be described later, when the vertically aligned liquid crystal layer contains a photo-isomerizable compound, a positive A plate can be directly formed on the vertically aligned liquid crystal layer, and the adhesion between the vertically aligned liquid crystal layer and the positive A plate can be improved. The photo-isomerizable compound is not particularly limited as long as it is a photo-isomerizable compound, and examples thereof include compounds having a photo-isomerizable group. Examples of the photo-isomerizable group include a cinnamoyl group, a chalcone group, an azobenzene group, and a stilbene group. The photo-isomerizable compound preferably contains a repeating unit having a photo-isomerizable group. The content of the repeating unit having a photo-isomerizable group is preferably 5 to 45% by mass with respect to all the repeating units contained in the photo-isomerizable compound.

[0082] The photo-isomerizable compound preferably contains a repeating unit having a group represented by the above formula (2). The content of the repeating unit having a group represented by formula (2) is preferably 20 to 60% by mass with respect to all the repeating units contained in the photo-isomerizable compound.

[0083] The thickness of the vertically aligned liquid crystal layer is not particularly limited, and is preferably 10 μm or less, more preferably 0.1 to 5.0 μm, in terms of more suppressing the occurrence of curl. Note that the thickness of the vertically aligned liquid crystal layer means the average thickness of the vertically aligned liquid crystal layer. The above average thickness is obtained by measuring the thicknesses of any five or more points of the vertically aligned liquid crystal layer and calculating their arithmetic mean. The thickness can be measured, for example, using a reflection spectroscopic film thickness meter FE3000.

[0084] When the vertically aligned liquid crystal layer is in direct contact with the positive A plate, from the viewpoint of adhesion, it is preferable that the vertically aligned liquid crystal layer contains a region (referred to as region B) containing a liquid crystal-derived component contained in the positive A plate. The thickness of region B is preferably 5 to 100 nm. The measurement method of region B is the same as that of region A.

[0085] <Adhesive layer> The adhesive layer is a layer formed using an adhesive. Examples of the adhesive include rubber-based adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl pyrrolidone adhesives, polyacrylamide adhesives, and cellulose adhesives, and acrylic adhesives or polyvinyl alcohol adhesives (PVA adhesives) are preferred. As the acrylic adhesive, a copolymer of a (meth)acrylate in which the alkyl group of the ester moiety is an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group or a butyl group, and a (meth)acrylic monomer having a functional group such as (meth)acrylic acid or hydroxyethyl (meth)acrylate is preferable. As the polyvinyl alcohol-based adhesive, an adhesive composed of polyvinyl alcohol or its derivative can be mentioned. Examples of the derivative of polyvinyl alcohol include polyvinyl formal and polyvinyl acetal. In addition, olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid and their alkyl esters, or those modified with acrylamide can be mentioned.

[0086] The thickness of the adhesive layer is not particularly limited, preferably 1 to 30 μm, more preferably 5 to 25 μm.

[0087] <Other layers> The polarizing plate with an adhesive layer of the present invention may contain other members other than the above-described various members. For example, the polarizing plate with an adhesive layer of the present invention may further have an adhesion layer in order to enhance the adhesion between members.

[0088] The adhesion layer is a layer selected from the group consisting of an adhesive layer and an adhesive layer. The adhesive layer is a layer formed by curing an adhesive. Examples of the adhesive include curable adhesives such as active energy ray curable adhesives and thermosetting adhesives. Examples of the active energy ray curable adhesives include electron beam curable adhesives, ultraviolet ray curable adhesives, and visible light curable adhesives, and ultraviolet ray curable adhesives are preferable. That is, the adhesion layer is preferably a layer formed by curing an ultraviolet ray curable adhesive. Specific examples of active energy ray-curable adhesives include (meth)acrylate adhesives. Examples of the curable component in (meth)acrylate adhesives include compounds having a (meth)acryloyl group and compounds having a vinyl group.

[0089] The thickness of the adhesive layer is not particularly limited, but is preferably 0.1 to 5 μm, more preferably 0.5 to 2 μm.

[0090] Examples of the pressure-sensitive adhesive layer include those exemplified as the pressure-sensitive adhesive layer contained in the above-mentioned polarizing plate with a pressure-sensitive adhesive layer.

[0091] In particular, it is preferable that the polarizer and the positive A plate are laminated via a pressure-sensitive adhesive layer, and it is more preferable that they are laminated via a polyvinyl alcohol-based pressure-sensitive adhesive. It is also preferable that the polarizer and the positive A plate are laminated via an adhesive layer formed by curing an ultraviolet-curable adhesive.

[0092] The pressure-sensitive adhesive layer-attached polarizing plate of the present invention may further have a cover film on the protective film to protect the protective film. The presence of the cover film can further prevent the protective film from being damaged during handling.

[0093] When the polarizing plate with an adhesive layer of the present invention is bonded to a glass substrate via an adhesive and a cross-cut test of 100 squares is performed on the bonded polarizing plate with an adhesive layer, it is preferable that the number of squares that peel off is 50 or less. In the present invention, a polymer film may be included as part of the positive C plate, but the polymer film is laminated with good adhesion to the adjacent layer, and therefore peeling is unlikely to occur in the cross-cut test. In other words, peeling is unlikely to occur between the polymer film and the layer adjacent to the polymer film in the cross-cut test. The cross-cut test can be carried out in accordance with JIS-K5600-5-6 (1999).

[0094] <Method for manufacturing a polarizing plate with an adhesive layer> The method for manufacturing a polarizing plate with an adhesive layer of the present invention is not particularly limited and can be manufactured by a known method. For example, various members constituting the polarizing plate with an adhesive layer are produced, and the various members are laminated via the above adhesion layer, or the polarizing plate with an adhesive layer may be manufactured by directly laminating the various members without passing through the adhesion layer. More specifically, while transporting the polarizer, a protective film is bonded to one surface side of the polarizer, and a laminated film including a positive A plate and a positive C plate is bonded to the other surface side of the polarizer to produce a polarizing plate, and an adhesive layer may be disposed on the positive C plate side of the obtained polarizing plate.

[0095] The positive A plate is preferably formed using a composition containing a polymerizable liquid crystal compound. More specifically, it is preferable to apply a composition containing a polymerizable liquid crystal compound, perform an alignment treatment on the formed coating film to align the polymerizable liquid crystal compound in the coating film, and perform a curing treatment to manufacture the positive A plate. Examples of the components contained in the above composition include the above-described polymerizable liquid crystal compound and a polymer having a group represented by the formula (1). Examples of other components that may be contained in the above composition include, in addition to the above, monomers, polymerization initiators, photoacid generators, alignment control agents (vertical alignment agents, horizontal alignment agents), surfactants, adhesion improvers, plasticizers, and solvents.

[0096] Examples of the object to which the composition is applied include a substrate having an alignment film. The alignment film may be an optical alignment film. Examples of the method for applying the composition include a curtain coating method, a dip coating method, a spin coating method, a printing coating method, a spray coating method, a slot coating method, a roll coating method, a slide coating method, a blade coating method, a gravure coating method, and a wire bar method.

[0097] The alignment treatment can be carried out by drying the coating film at room temperature or by heating the coating film. The liquid crystal phase formed by the alignment treatment can generally be transferred by a change in temperature or pressure in the case of a thermotropic liquid crystal compound. In the case of a lyotropic liquid crystal compound, it can also be transferred by a composition ratio such as the amount of solvent. In addition, the conditions for heating the coating film are not particularly limited, but the heating temperature is preferably 50 to 250 °C, more preferably 50 to 150 °C, and the heating time is preferably 10 seconds to 10 minutes. Further, after heating the coating film and before the curing treatment (light irradiation treatment) described later, the coating film may be cooled as necessary.

[0098] The method of the curing treatment performed on the coating film in which the polymerizable liquid crystal compound is aligned is not particularly limited, and examples thereof include a light irradiation treatment and a heat treatment. Among them, from the viewpoint of production suitability, the light irradiation treatment is preferable, and the ultraviolet irradiation treatment is more preferable. The irradiation conditions of the light irradiation treatment are not particularly limited, but an irradiation amount of 50 to 1000 mJ / cm 2 is preferable. The atmosphere during the light irradiation treatment is not particularly limited, but a nitrogen atmosphere is preferable.

[0099] As a method for manufacturing a positive C plate, a method using a composition containing a polymerizable liquid crystal compound can be mentioned in the same manner as the method for manufacturing the positive A plate described above. The composition may contain a polymerizable liquid crystal compound, a crosslinkable polymer, and a photo-isomerizable compound. When the composition contains a photo-isomerizable compound, the photo-isomerizable compound may have a polymerizable group. In addition, when the positive C plate includes a vertically aligned liquid crystal layer and a polymer film, the above composition may be applied onto the polymer film to form a vertically aligned liquid crystal layer.

[0100] Further, in the present invention, a composition for forming a positive A plate may be applied onto the positive C plate to form a positive A plate directly laminated on the positive C plate. In the case of the above procedure, a photo-isomerizable compound can be disposed on the surface side of the positive C plate on the side forming the positive A plate, and the photo-isomerizable compound can be irradiated with light to impart the function as a photo-alignment film. For example, when the positive C plate includes a vertically aligned liquid crystal layer and a polymer film, and a composition is applied on the vertically aligned liquid crystal layer to form the positive A plate, the photo-isomerizable compound is disposed on the surface opposite to the polymer film side of the vertically aligned liquid crystal layer, and the photo-isomerizable compound is irradiated with light to orient the photo-isomerizable group contained in the photo-isomerizable compound, thereby imparting an aligning ability to the surface of the vertically aligned liquid crystal layer.

[0101] <Use> The polarizing plate with an adhesive layer of the present invention can be suitably applied to a display device. More specifically, the polarizing plate with an adhesive layer of the present invention having the above configuration is suitably used for antireflection applications of display devices such as liquid crystal display devices (LCDs), plasma display panels (PDPs), electroluminescence displays (ELDs), and cathode ray tube display devices (CRTs). The display device of the present invention includes a display element and the above-described polarizing plate with an adhesive layer. When applying the polarizing plate with an adhesive layer of the present invention to a display device, a method of bonding the display element and the polarizing plate with an adhesive layer with the adhesive layer in the polarizing plate with an adhesive layer facing the display element side can be mentioned. The display element is not particularly limited, and examples include an organic electroluminescence display element and a liquid crystal display element.

Example

[0102] Examples and comparative examples are given below to more specifically explain the features of the present invention. Materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed restrictively by the specific examples shown below.

[0103] <Example 1> (Production of cellulose acylate film (1)) The following composition was charged into a mixing tank, stirred, and further heated at 90 °C for 10 minutes. Thereafter, the resulting composition was filtered through filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm to prepare a dope. The solid content concentration of the dope was 23.5% by mass, and the solvent of the dope was methylene chloride / methanol / butanol = 81 / 18 / 1 (mass ratio).

[0104] ――――――――――――――――――――――――――――――――― Cellulose acetate dope ――――――――――――――――――――――――――――――――― Cellulose acetate (degree of acetyl substitution 2.86, viscosity average degree of polymerization 310) 100 parts by mass Sugar ester compound 1 (shown in the following formula (S4)) 6.0 parts by mass Sugar ester compound 2 (shown in the following formula (S5)) 2.0 parts by mass Silica particle dispersion (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by mass Solvent (methylene chloride / methanol / butanol) ―――――――――――――――――――――――――――――――――

[0105]

Chem.

[0106]

Chem.

[0107] The dope prepared above was cast using a drum film former. The dope was cast from a die so as to contact a metal support cooled to 0 °C, and then the obtained web (film) was peeled off. The drum was made of SUS.

[0108] The web (film) obtained by casting was peeled off from the drum and then dried in a tenter device for 20 minutes at 30 - 40 °C inside the tenter device while conveying the film, with both ends of the web clipped by clips. Subsequently, the web was post - dried by zone heating while being conveyed in a roll. After applying naring to the obtained web, it was wound up to produce a cellulose acetate film (1) with a film thickness of 40 μm. The in - plane retardation of the cellulose acetate film (1) at a wavelength of 550 nm was 0 nm, and the thickness - direction retardation at a wavelength of 550 nm was 23 nm.

[0109] (Formation of positive C - plate (1A)) Using a geyser coater on the above - mentioned cellulose acetate film (1), a composition for forming a vertically aligned liquid - crystal layer (1A) containing a rod - shaped liquid - crystal compound with the following composition was applied to form a composition layer. The film with the composition layer formed was heated at 60 °C for 1 minute with warm air and irradiated with ultraviolet light with an irradiation dose of 100 mJ / cm 2 using a 365 - nm UV - LED while purging with nitrogen to make the atmosphere have an oxygen concentration of 100 volume ppm or less. Then, the obtained coating film was annealed at 130 °C for 1 minute with warm air to form a positive C - plate (1A) with a thickness of 40.7 μm and a vertically aligned liquid - crystal layer (1A) with a thickness of 0.7 μm on the cellulose acetate film (1). Note that the ends of the positive C - plate (1A) Note that the in - plane retardation Re of the positive C - plate (1A) at a wavelength of 550 nm was 0 nm, and the thickness - direction retardation Rth at a wavelength of 550 nm was - 85 nm. The average inclination angle of the long - axis direction of the rod - shaped liquid - crystal compound with respect to the film plane was 90°, and it was confirmed that it was vertically aligned with respect to the film plane.

[0110] ―――――――――――――――――――――――――――――――― Composition for forming vertically aligned liquid - crystal layer (1A) ―――――――――――――――――――――――――――――――― 100 parts by mass of the following rod-shaped liquid crystal compound (A): Polymerizable monomer (A-400, manufactured by Shin-Nakamura Chemical Co., Ltd.) 4.2 parts by mass 5.1 parts by mass of the following polymerization initiator S-1 (oxime type) 3.0 parts by mass of the following photoacid generator D-1 4.0 parts by mass of the following polymer M-1 1.9 parts by mass of the following alignment control agent A-1 0.8 parts by mass of the following photo-alignment polymer PA-1 Diisopropylethylamine 0.2 parts by mass Methyl ethyl ketone 93.8 parts by mass Methyl isobutyl ketone 372.0 parts by mass ----------------------------------------------------------------------------------

[0111] Rod-like liquid crystal compound (A) (hereinafter referred to as a compound mixture. The numerical values indicate the mass ratio.)

[0112] [ka]

[0113] Polymerization initiator S-1

[0114] [ka]

[0115] Photoacid generator D-1

[0116] [ka]

[0117] Polymer M-1 (weight average molecular weight was 52,000. The numerical values shown in the repeating units indicate the content (% by mass) of each repeating unit relative to all repeating units.)

[0118] [ka]

[0119] Alignment control agent A-1

[0120]

Chemical formula

[0121] Photo-alignment polymer PA-1 (The numerical values described in the repeating unit represent the content (mass %) of each repeating unit with respect to all repeating units. Weight-average molecular weight: 90,000. Me represents a methyl group.)

[0122]

Chemical formula

[0123] (Fabrication of positive A plate (1B)) On the vertical alignment liquid crystal layer (1A) side of the long positive C plate (1A), UV light (ultra-high pressure mercury lamp; UL750; manufactured by HOYA) passed through a wire grid polarizer was irradiated at 7.9 mJ / cm 2 (Wavelength: 313 nm) to form a composition layer having alignment control ability on the surface. Subsequently, using a dispenser, a composition (1B) for forming a horizontally aligned liquid crystal layer containing a rod-shaped liquid crystal compound of the following composition was applied onto the vertical alignment liquid crystal layer (1A). After heating to 120 °C with warm air once and then cooling to 60 °C to stabilize the alignment. Then, using an ultra-high pressure mercury lamp under a nitrogen atmosphere (oxygen concentration less than 100 ppm), while maintaining the film temperature at 60 °C, after the first ultraviolet irradiation (80 mJ / cm 2 ), while maintaining the film temperature at 100 °C, the second ultraviolet irradiation (300 mJ / cm 2 ) was performed to fix the alignment and form a positive A plate (1B). Note that the ends of the positive A plate (1B) were formed 10 mm inward from the ends of the cellulose acetate film. The thickness of the positive A plate (1B) was 2.8 μm, and the Re(550) at a wavelength of 550 nm was 141 nm. When the width direction of the film was set to 0° (the longitudinal direction was 90°), the in-plane slow axis direction (the orientation axis angle of the liquid crystal compound) was 45°.

[0124] ---------------------------------------------------------------------------------- Composition for forming horizontally aligned liquid crystal layer (1B) ---------------------------------------------------------------------------------- 8.5 parts by mass of the following rod-shaped liquid crystal compound (B) 8.5 parts by mass of the following rod-shaped liquid crystal compound (C) 45.0 parts by mass of the following rod-shaped liquid crystal compound (D) 32.0 parts by mass of the following rod-shaped liquid crystal compound (E) 6.0 parts by mass of the following rod-shaped liquid crystal compound (F) 0.5 parts by mass of the above polymerization initiator S-1 (oxime type) 0.1 parts by mass of the following leveling agent L-1 Tetrahydrofuran 233.2 parts by mass Cyclopentanone 58.3 parts by mass Methylthiobenzothiazole 12.0 parts by mass ----------------------------------------------------------------------------------

[0125] Rod-shaped liquid crystal compound (B)

[0126] [ka]

[0127] Rod-shaped liquid crystal compound (C)

[0128] [ka]

[0129] Rod-shaped liquid crystal compound (D)

[0130] [Chemistry]

[0131] Rod-like liquid crystal compound (E)

[0132] [Chemistry]

[0133] Rod-like liquid crystal compound (F)

[0134] [Chemistry]

[0135] Leveling agent L-1 (weight average molecular weight was 28,500. The numerical values in the repeating unit represent the content (mass %) of each repeating unit with respect to all repeating units.)

[0136] [Chemistry]

[0137] By the above procedure, a long laminated film (1) with a thickness of 43.5 μm in which a positive C plate (1A) and a positive A plate (1B) were directly laminated was produced.

[0138] (Preparation of aqueous adhesive 1) To 100 parts of water, 3 parts of carboxy group-modified polyvinyl alcohol (Kuraray Poval KL318 manufactured by Kuraray Co., Ltd.) and 1.5 parts of water-soluble polyamide epoxy resin (Sumirez resin 650 manufactured by Tago Chemical Industry Co., Ltd., aqueous solution with a solid content concentration of 30%) were added to prepare aqueous adhesive 1.

[0139] (Preparation of adhesive layer) In the same manner as described in Example 1 of JP-A-2023-126297, an adhesive layer (acrylic adhesive) with a thickness of 20 μm was formed on a separator film.

[0140] (Production of Polarizer 1) A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2,400, and a saponification degree of 99.9% or more was uniaxially stretched to a draw ratio of 4.5 times by a dry method. While maintaining the tension state, it was immersed in a dyeing bath at 28 °C containing 0.05 parts by weight of iodine and 5 parts by weight of potassium iodide per 100 parts by weight of water for 60 seconds.

[0141] Next, it was immersed in Boric acid aqueous solution 1 at 64 °C containing 2.3 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water for 110 seconds. Then, it was immersed in Boric acid aqueous solution 2 at 67 °C containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water for 30 seconds. Thereafter, it was washed with pure water at 10 °C and dried to obtain Polarizer 1. The boron content of Polarizer 1 was 2.76% by weight. The thickness of the polarizer was 8 μm.

[0142] (Production of Polarizing Plate (P1)) The surface of the support of cellulose triacetate film TJ25 (manufactured by Fuji Film Co., Ltd.: thickness 25 μm) was subjected to an alkali saponification treatment. Specifically, after immersing the support in a 1.5 N aqueous sodium hydroxide solution at 55 °C for 2 minutes, the support was washed in a water bath at room temperature and then neutralized using 0.1 N sulfuric acid at 30 °C. After neutralization, the support was washed in a water bath at room temperature and further dried with warm air at 100 °C to obtain a polarizer protection film (1). A polarizing protective film (1) was laminated on one surface of the polarizer 1 with a nip roll via the aqueous adhesive 1 to obtain a linearly polarized light plate. The positive A plate (1B) surface of the laminated film (1) was laminated on the other surface of the polarizer of the linearly polarized light plate with a nip roll via the aqueous adhesive 1. Note that the end of the aqueous adhesive 1 was formed 15 mm inward from the end of the cellulose acylate film. Subsequently, a laminate film made of a 50-μm-thick PET (polyethylene terephthalate) film with a weak adhesive was laminated on the polarizing protective film (1) side. Thereafter, the adhesive layer formed on the separator film was laminated on the laminated film (1) side. By the above procedure, a polarizing plate (P1) with an adhesive layer was produced. At this time, the laminate film, the polarizing protective film (1), the aqueous adhesive 1, the polarizer (1), the aqueous adhesive 1, the positive A plate (1B), the positive C plate (1A) (the vertically aligned liquid crystal layer (1A), the cellulose acylate film (1)), the adhesive, and the separator film were laminated in this order, and the angle formed by the absorption axis of the polarizer (1) and the in-plane slow axis of the positive A plate (1B) was 45°.

[0143] <Example 2> Before lamination, a polarizing plate (P2) with an adhesive layer was produced in the same manner as in Example 1, except that the positive A plate (1B) surface of the laminated film (1) was subjected to corona treatment (60 Wmin / m 2 ).

[0144] <Example 3> Before lamination, a polarizing plate (P3) with an adhesive layer was produced in the same manner as in Example 1, except that the positive A plate (1B) surface of the laminated film (1) was subjected to plasma treatment by the following method. (Plasma treatment) The plasma treatment was carried out using an apparatus having a configuration according to the plasma generation apparatus described in Example 1 of JP-A-2018-170183. At that time, in the plasma generation apparatus, helium gas, oxygen gas, and nitrogen gas were introduced between the electrode and the counter electrode so that the volume flow ratio was 10 / 0.025 / 0.5, and 6000 W of power was applied to the electrode to generate plasma between the electrode and the counter electrode. Also, the conveyance speed of the laminated film (1) conveyed between the electrode and the counter electrode was 10.0 m / min. The gas composition (analyzed by gas chromatography) of the plasma raw material gas introduced into the plasma generation apparatus was 94.1 vol% / 0.4 vol% / 5.5 vol% of helium gas, oxygen gas, and nitrogen gas.

[0145] <Example 4> A polarizing plate with an adhesive layer (P4) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 4. (Preparation of aqueous adhesive 4) 3 parts of carboxy group-modified polyvinyl alcohol (Kuraray Poval KL318 manufactured by Kuraray Co., Ltd.) was added to 100 parts of water to prepare aqueous adhesive 4.

[0146] <Example 5> A polarizing plate with an adhesive layer (P5) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to an aqueous adhesive 5 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimer (registered trademark) Z-200", an aqueous PVA resin solution with a resin concentration of 3% by weight and a moisture content of 97%).

[0147] <Example 6> A polarizing plate with an adhesive layer (P6) was produced in the same manner as in Example 2, except that the aqueous adhesive 1 was changed to the above aqueous adhesive 5.

[0148] <Example 7> A polarizing plate with an adhesive layer (P7) was produced in the same manner as in Example 3, except that the aqueous adhesive 1 was changed to the above aqueous adhesive 5.

[0149] <Example 8> A polarizing plate with an adhesive layer (P8) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 8. (Preparation of Aqueous Adhesive 8) 50 g of a modified PVA-based resin containing an acetoacetyl group (“Gohsenex Z-410” manufactured by Mitsubishi Chemical Corporation) was dissolved in 950 g of pure water. This solution was heated at 90°C for 2 hours and then cooled to room temperature to obtain a PVA solution A for an adhesive. Next, the PVA solution A, maleic acid, glyoxal, ethanol, and pure water were blended so that each component had the following concentration (mass %) to prepare an aqueous adhesive 8. ·PVA 3.00% ·Maleic acid 0.01% ·Glyoxal 0.15% ·Ethanol 20.00% ·Water 76.84%

[0150] <Example 9> A polarizing plate with an adhesive layer (P9) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 9. (Preparation of Aqueous Adhesive 9) To 100 parts of a polyvinyl alcohol-based resin containing an acetoacetyl group (average degree of polymerization: 1200, degree of saponification: 98.5 mol%, degree of acetoacetyl group modification: 5 mol%), 20 parts of methylol melamine was dissolved in pure water under a temperature condition of 30°C to prepare an aqueous solution adjusted to a solid content concentration of 3.2% by weight. This was used as the aqueous adhesive 9.

[0151] <Example 10> A polarizing plate with an adhesive layer (P10) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 10. (Preparation of Aqueous Adhesive 10) 6.02 parts of acetoacetyl-modified PVA (degree of polymerization: 1200, degree of acetoacetyl modification: 4.6%, degree of saponification: 99.0 mol% or more, solid content concentration: 4%, manufactured by Mitsubishi Chemical Corporation, trade name "Gosenex Z-200"), 25 parts of an aqueous solution containing a positively charged alumina colloid (average particle diameter: 15 nm) at a solid content concentration of 3.2%, and 18.98 parts of pure water were mixed to obtain an aqueous adhesive 10.

[0152] <Example 11> A polarizing plate with an adhesive layer (P11) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 11. (Preparation of aqueous adhesive 11) To 100 parts of a polyvinyl alcohol-based resin containing an acetoacetyl group (average degree of polymerization: 1200, degree of saponification: 98.5 mol%, degree of acetoacetylation: 5 mol%), 50 parts of methylol melamine was dissolved in pure water under temperature conditions of 30°C, and an aqueous solution adjusted to a solid content concentration of 3.7% was prepared. To 100 parts of the aqueous solution, 18 parts of an alumina colloid aqueous solution (average particle diameter: 15 nm, solid content concentration: 10%, positive charge) was added to prepare an aqueous adhesive 11.

[0153] <Example 12> A polarizing plate with an adhesive layer (P12) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 12. (Preparation of aqueous adhesive 12) 100 parts by weight of a PVA resin (Ecomate, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and 35 parts by weight of a crosslinking agent (Waterzol, manufactured by Dainippon Ink and Chemicals, Inc.) were dissolved in 3760 parts by weight of pure water to prepare an aqueous adhesive 12.

[0154] <Example 12> A polarizing plate with an adhesive layer (P12) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 12. (Preparation of aqueous adhesive 12) 100 parts by weight of a PVA resin (manufactured by Nippon Gohsei Chemical Industry Co., Ltd.: Ecomatty) and 35 parts by weight of a crosslinking agent (manufactured by Dainippon Ink and Chemicals, Inc.: Waterzol) were dissolved in 3760 parts by weight of pure water to prepare an aqueous adhesive 12.

[0155] <Example 13> A polarizing plate with an adhesive layer (P13) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 13. (Preparation of aqueous adhesive 13) 100 parts by weight of a PVA resin (manufactured by Nippon Gohsei Chemical Industry Co., Ltd.: Gosefimer Z: containing an acetoacetyl group) and 35 parts by weight of a crosslinking agent (manufactured by Dainippon Ink and Chemicals, Inc.: Waterzol) were dissolved in 3760 parts by weight of pure water to prepare an aqueous adhesive 13.

[0156] <Example 14> A polarizing plate with an adhesive layer (P14) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 14.

[0157] (Preparation of PVA solution) 50 g of a modified PVA-based resin containing an acetoacetyl group (manufactured by Mitsubishi Chemical Corporation: Gosenex Z-410) was dissolved in 950 g of pure water, heated at 90 °C for 2 hours, and then cooled to room temperature to obtain a PVA solution for adhesive.

[0158] (Preparation of antioxidant solution) 0.25 g of Irganox 1010 (manufactured by BASF Japan Ltd.), a phenolic antioxidant, was added to 100 g of ethanol to prepare an antioxidant solution.

[0159] (Preparation of aqueous adhesive 14) The PVA solution for adhesive, the antioxidant solution, and pure water prepared above were blended so that the PVA concentration was 3.0%, the ethanol concentration was 30%, and the Irganox 1010 concentration was 0.075% to obtain an aqueous adhesive 14.

[0160] <Example 15> An aqueous adhesive 15 and a polarizing plate with an adhesive layer (P15) were produced in the same manner as in Example 14, except that the antioxidant solution described in Example 14 was changed to the following ultraviolet absorber solution. (Preparation of Ultraviolet Absorber Solution) 0.25 g of a water-soluble ultraviolet absorber OUV-016 (manufactured by Fuji Film Co., Ltd.) was added to 100 g of pure water to prepare an ultraviolet absorber solution.

[0161] <Example 16> A polarizing plate with an adhesive layer (P16) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 16. (Preparation of Aqueous Adhesive 16) An acetylacetonyl group-modified polyvinyl alcohol-based resin (manufactured by Mitsubishi Chemical Corporation, "Gosenol Z200") with a saponification degree of 99.2 mol% was dissolved in water (distilled water) to prepare a PVA aqueous solution with a solid content of 8% by mass. The prepared 8% by mass PVA solution was mixed with a 40% aqueous solution of glyoxal as a crosslinking agent so that the mass ratio was 3.0:0.7, and further adjusted so that the total solid content was 3 parts per 100 parts of water to obtain a PVA-based resin composition A. Separately, an acetylacetonyl group-modified polyvinyl alcohol-based resin (manufactured by Mitsubishi Chemical Corporation, "Gosenol Z200") with a saponification degree of 99.2 mol% was dissolved in water (distilled water) to prepare a PVA aqueous solution with a solid content of 8% by mass. The prepared 8% by mass PVA solution was mixed with zinc chloride so that the mass ratio was 3.0:0.09, and further adjusted so that the total solid content was 3 parts per 100 parts of water to obtain a PVA-based resin composition B. The PVA-based resin compositions A and B prepared above were mixed at a mass ratio of 1:1 at room temperature and stirred for 30 minutes to prepare an aqueous adhesive 16.

[0162] <Example 17> A polarizing plate with an adhesive layer (P17) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 17. ─────────────────────────────────── Composition of Aqueous Adhesive 17 ─────────────────────────────────── 2.4 parts by mass of polyvinyl alcohol PVA117 (manufactured by Kuraray Co., Ltd.) 0.6 part by mass of the following modified polyvinyl alcohol 1.6 parts by mass of isopropyl alcohol 90.0 parts by mass of water ───────────────────────────────────

[0163]

Chemical formula

[0164] <Example 18> A polarizing plate with an adhesive layer (P18) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 18. (Preparation of aqueous adhesive 18) (A) A 5 wt% aqueous solution of polyvinyl alcohol with a polymerization degree of 500 and (B) a 2 wt% aqueous solution of sodium carboxymethyl cellulose were mixed to prepare an aqueous adhesive 18. The mixing ratio of (A) and (B) was (A):(B) = 20:1.

[0165] <Example 19> A polarizing plate with an adhesive layer (P19) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 19. (Preparation of aqueous adhesive 19) A polyvinyl alcohol resin (average degree of polymerization 2000, saponification degree 94%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) containing an acetoacetyl group (5% by weight) was dissolved in pure water to produce a 4% by weight aqueous solution. To this, a titanium amine complex crosslinking agent (product name: TYZOR TE, manufactured by DuPont) was added at a ratio of 6.7 parts by weight per 100 parts by weight of the polyvinyl alcohol resin and stirred. Next, after preparing a pH adjuster containing 5 parts by weight of glycidyl methacrylate, 28.5 parts by weight of methanol, and 66.5 parts by weight of hydrochloric acid, the pH adjuster was added to the polyvinyl alcohol resin aqueous solution so that the pH became 7 to produce an aqueous adhesive 19.

[0166] <Example 20> A polarizing plate with an adhesive layer (P20) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 20. (Preparation of aqueous adhesive 20) To 100 parts of Hydran AP-20 (manufactured by Dainippon Ink and Chemicals, Inc., an aqueous emulsion of a polyester-based ionomer urethane resin, solid content concentration 30%, viscosity 30 mPa·sec), 5 parts of CR-5L (manufactured by Dainippon Ink and Chemicals, Inc.), a polyfunctional glycidyl ether, was added to obtain a polyurethane-based adhesive (A).

[0167] <Example 21> A polarizing plate with an adhesive layer (P21) was produced in the same manner as in Example 1, except that the aqueous adhesive 1 was changed to the following aqueous adhesive 21. (Preparation of aqueous adhesive 21) 3 parts by weight of an epoxy-based curing agent SR-4GL (product with 100% active ingredient, manufactured by Sakamoto Pharmaceutical Co., Ltd.) was blended with 100 parts by weight of SE-2716L (manufactured by Daiso Fine Chemical Co., Ltd.) (aqueous solution with a solid content concentration of 40%) to adjust the aqueous adhesive 21.

[0168] <Example 22> A polarizer protective film (Polarizer protective film (1)) was changed to a polarizer protective film (2) with a thickness of 40 μm made of a norbornene resin subjected to corona treatment (Zeonoa film manufactured by Optes Co., Ltd.), and a polarizing plate with an adhesive layer (P22) was produced in the same manner as in Example 20 except for this change.

[0169] <Example 23> A polarizing plate with an adhesive layer (P23) was produced in the same manner as in Example 1 except that the distance from the end of the cellulose acetate film to the end where the aqueous adhesive 1 was applied was changed to 8 mm.

[0170] <Example 24> (Production of Polarizer 2) As the resin substrate, an amorphous isophthalic acid copolymer polyethylene terephthalate (IPA copolymer PET) film (thickness: 100 μm) in a long strip shape with a water absorption rate of 0.75% and a Tg of 75 °C was used. One side of the substrate was subjected to corona treatment, and an aqueous solution containing polyvinyl alcohol (degree of polymerization 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (degree of polymerization 1200, degree of acetoacetyl modification 4.6%, saponification degree 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimer Z200") in a ratio of 9:1 was applied and dried at 25 °C to form a PVA-based resin layer with a thickness of 13 μm, and a laminate was produced. The obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 120 °C with free ends (air-assisted stretching). Next, the laminate was immersed in an insolubilization bath at a liquid temperature of 30 °C (an aqueous boric acid solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment). Next, the laminate was immersed in a dyeing bath at a liquid temperature of 30 °C while adjusting the iodine concentration and immersion time so that the polarizing plate had a predetermined transmittance. In this example, it was immersed in an iodine aqueous solution obtained by mixing 0.2 parts by weight of iodine and 1.5 parts by weight of potassium iodide with 100 parts by weight of water for 60 seconds (dyeing treatment). Next, it was immersed in a crosslinking bath at a liquid temperature of 30 °C (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds (crosslinking treatment). Thereafter, while immersing the laminate in an aqueous boric acid solution at a liquid temperature of 70 °C (an aqueous solution obtained by blending 3 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water), uniaxial stretching was performed in the longitudinal direction (lengthwise direction) between rolls with different peripheral speeds so that the total draw ratio became 5.5 times (stretching in water). Thereafter, the laminate was immersed in a washing bath at a liquid temperature of 30 °C (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) (washing treatment). Subsequently, an ultraviolet curable adhesive shown below was applied to the surface of the PVA-based resin layer of the laminate so that the adhesive layer thickness after curing was 1.0 μm, and a polarizer protection film (3) (Zeonoa-based resin film (thickness 17 μm) manufactured by Zeon Corporation) was laminated. Then, it was heated to 50 °C using an IR heater from the side of the polarizer protection film (3), and the following ultraviolet rays were irradiated to cure the adhesive. Thereafter, the substrate was peeled off from the PVA-based resin layer, and a long single-sided polarizing plate in which the polarizer 2 was laminated on the polarizer protection film (3) via the ultraviolet curable adhesive was obtained. The thickness of the polarizer 2 was 5 μm, and the single transmittance was 40.8%. (Adjustment of ultraviolet curable adhesive) 40 parts by weight of N-hydroxyethylacrylamide (HEAA), 60 parts by weight of acryloylmorpholine (ACMO), and 3 parts by weight of a photoinitiator “IRGACURE 819” (manufactured by BASF) were mixed to prepare an adhesive having a viscosity of 40 mPa·S before curing. (Ultraviolet rays) As the active energy rays, ultraviolet rays (a gallium-encapsulated metal halide lamp, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illuminance: 1600 mW / cm2, integrated irradiation dose 1000 / mJ / cm2 (wavelength 380 - 440 nm)) were used. The illuminance of the ultraviolet rays was measured using a Sola-Check system manufactured by Solatell. (Production of polarizing plate (P24)) On the polarizer (2) surface of the above-mentioned single-sided polarizing plate, an aqueous adhesive (PVA-based resin aqueous solution with a resin concentration of 3% by weight and a moisture content of 97%, trade name "Gosefimer (registered trademark) Z-200" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was applied so that the thickness of the adhesive layer after heating would be 0.1 μm, and a laminated film (1) (thickness 43.5 μm) in which the positive C plate (1A) and the positive A plate (1B) described in Example 1 were directly laminated was bonded, and it was heated in an oven maintained at 80 °C for 5 minutes. Subsequently, a laminate film made of a 50-μm-thick PET (polyethylene terephthalate) film with a weak adhesive was bonded to the side of the polarizer protective film (3). Then, an adhesive layer formed on the separator film was bonded to the side of the laminated film (1). By the above procedure, a polarizing plate with an adhesive layer (P24) was produced. At this time, the laminate film, the polarizer protective film (3), the ultraviolet-curing adhesive, the polarizer (2), the aqueous adhesive 24, the positive A plate (1B), the positive C plate (1A) (the vertical alignment liquid crystal layer (1A), the cellulose acylate film (1)), the adhesive, and the separator film were laminated in this order, and the angle formed by the absorption axis of the polarizer (2) and the in-plane retardation axis of the positive A plate (1B) was 45°.

[0171] <Measurement of optical properties> Using AxoScan OPMF-1 (manufactured by Optoscience Co., Ltd.), at a wavelength of 550 nm, the light incident angle dependence of Re and the tilt angle of the optical axis (that is, the tilt with respect to the plane of the optical anisotropic layer in the direction in which the refractive index of the optical anisotropic layer is maximum) were measured, and the in-plane retardation Re at a wavelength of 550 nm and the retardation Rth in the thickness direction at a wavelength of 550 nm of the optical anisotropic layer were respectively obtained.

[0172] <Measurement of the film thickness of the laminated film> Using a contact type film thickness gauge, the thickness of the laminated film was measured.

[0173] <Measurement of the film thickness of the liquid crystal layer> Using a reflection spectroscopic film thickness gauge FE3000 (manufactured by Otsuka Electronics Co., Ltd.), the thickness of the liquid crystal layer was measured.

[0174] <Measurement of Film Thickness of Laminated Film and Polymer Film> Using a contact thickness gauge, the thicknesses of the laminated film and the polymer film were measured.

[0175] <Adhesion Evaluation> The produced polarizing plate with an adhesive layer was cut into strips of 30 mm × 120 mm, and the separator film on the adhesive layer side was peeled off. After the exposed adhesive layer was bonded to glass, the laminate film on the opposite side was peeled off. From the surface of the polarizing plate, 11 cuts were made at 1 mm intervals to a depth reaching the adhesive bonded to the glass, and 11 more cuts were made in the same way in the orthogonal direction, thereby forming 100 meshes. An adhesive tape (Polyester Adhesive Tape NO. 31B, manufactured by Nitto Denko Corporation) was pasted on the meshes, the tape was peeled off at an angle of about 60°, the number of peeled meshes was counted, and based on the results, the following criteria were used for evaluation. A: The number of peeled meshes is 50 or less B: The number of peeled meshes is 51 or more

[0176] <Evaluation of Processability (Curl)> The polarizing plates with adhesive layers obtained in each example and comparative example were cut into a size of 200 mm × 200 mm so that the MD direction became the diagonal line, the separator film was peeled off, and samples were prepared. Next, the obtained samples were left in an environment of 25°C and 60% for 3 hours or more, then placed on a glass substrate with the peeled surface facing up, and evaluated as follows. The more it is A, the more the curl of the polarizing plate with an adhesive layer is suppressed. A: The lift of the polarizing plate from the substrate is 10 mm or less, and it can be easily bonded. B: The lift of the polarizing plate from the substrate is greater than 10 mm and 20 mm or less, and it can be bonded. C: The lift of the polarizing plate from the substrate is greater than 20 mm and 30 mm or less, and it can be bonded. D: The lift of the polarizing plate from the substrate is greater than 30 mm, and bonding is difficult.

[0177] <Reworkability Evaluation> From the commercially available smartphone Galaxy A1 (manufactured by SAMUSUNG), the cover glass and the polarizing plate were peeled off to expose the glass on the surface of the OLED substrate. The polarizing plate with the adhesive layer prepared above was cut to the same size as the smartphone, the separator film was peeled off, and it was bonded to the glass on the surface of the OLED substrate using a roller. After leaving the obtained sample in an environment of 25 °C and 60% for 24 hours, the polarizing plate with the adhesive layer was carefully peeled off, and the reworkability was evaluated according to the following criteria. A: Nothing remains on the glass, and it can be peeled off cleanly. B: Part of the adhesive and the liquid crystal cured film remained on the glass, and when trying to remove it, the glass broke, so it could not be removed.

[0178] <Fabrication of Organic EL Display Device> (Mounting on Display Device) The Apple iPhone 14 Pro equipped with an organic EL panel was disassembled, and the front glass plate and the circular polarizing plate were peeled off. It was confirmed by SEM-EDX (SU-8030 manufactured by Hitachi High-Tech Corporation) that a thin film encapsulation layer made of silicon nitride (SiN) or silicon oxynitride (SiON) was formed on the surface of the organic EL panel. The circular polarizing plate prepared above was bonded to the surface of the disassembled organic EL panel via a pressure-sensitive adhesive SK-2057 (manufactured by Soken Chemical & Engineering Co., Ltd.) to fabricate an evaluation panel.

[0179] 〔Evaluation of Display Performance〕 The fabricated evaluation panel was observed from the front direction under bright light, and the color tint was evaluated according to the following criteria. The results are shown in Table 3 below. A: The color tint is not visible at all, or if visible, it is slight. (Acceptable) B: The color tint is visible, but the reflected light is small and there is no problem in use. (Acceptable)

[0180] In Table 1, the column "Positive C film thickness (μm)" represents the film thickness (μm) of the positive C plate. In Table 1, the column "Crosslinkable Polymer" indicates whether a cured product of a crosslinkable polymer is included in the vertically aligned liquid crystal layer. "A" indicates inclusion, and "B" indicates non-inclusion. In the case of the evaluation of "A", the cured product of the crosslinkable polymer was unevenly distributed on the cellulose acylate film (polymer film) side in the positive C plate in the vertically aligned liquid crystal layer. In Table 1, the column "Photoisomerization Compound" indicates whether a photoisomerization compound is included in the vertically aligned liquid crystal layer. "A" indicates inclusion, and "B" indicates non-inclusion. In the case of the evaluation of "A", the photoisomerization compound was present on the surface opposite to the cellulose acylate film (polymer film) side in the positive C plate in the vertically aligned liquid crystal layer. In Table 1, the column "Formula (1)" indicates whether the positive A plate contains a polymer having a group represented by the above formula (1). "A" indicates inclusion, and "B" indicates non-inclusion.

[0181]

Table 1

[0182] As shown in the above table, the polarizing plate with an adhesive layer of the present invention showed a desired effect.

Explanation of Reference Numerals

[0183] 10 Polarizing plate with an adhesive layer 12 Polarizing plate 14 Protective film 16 Polarizer 18 Positive A plate 20 Positive C plate 22 Adhesive layer 24 Vertically aligned liquid crystal layer 26 Polymer film

Claims

1. A polarizing plate having a protective film, a polarizer, a positive A plate, and a positive C plate in this order, and an adhesive layer disposed on the positive C plate side of the polarizing plate, the polarizing plate with an adhesive layer, wherein the positive A plate is a layer obtained by curing a polymerizable liquid crystal compound, the thickness of the positive C plate is 20.0 to 70.0 μm, the polarizing plate with an adhesive layer.

2. When the polarizing plate with an adhesive layer is bonded to a glass substrate via the adhesive and a 100-mesh cross-cut test is performed on the bonded polarizing plate with an adhesive layer, the number of peeled meshes is 50 or less, the polarizing plate with an adhesive layer according to Claim 1.

3. The retardation in the thickness direction of the positive C plate at a wavelength of 550 nm is -100 to -30 nm, the polarizing plate with an adhesive layer according to Claim 1.

4. The positive C plate includes a polymer film, the polarizing plate with an adhesive layer according to Claim 1.

5. The polymer film is a cellulose acylate film, the polarizing plate with an adhesive layer according to Claim 4.

6. The in-plane retardation of the polymer film at a wavelength of 550 nm is 10 nm or less, the polarizing plate with an adhesive layer according to Claim 4.

7. The retardation in the thickness direction of the polymer film at a wavelength of 550 nm is -100 to 30 nm, the polarizing plate with an adhesive layer according to Claim 4.

8. The positive C plate includes a vertically aligned liquid crystal layer and the polymer film, the polarizing plate with an adhesive layer according to Claim 4.

9. The vertically aligned liquid crystal layer includes an aggregate unevenly distributed on the polymer film side, the polarizing plate with an adhesive layer according to Claim 8.

10. The vertically aligned liquid crystal layer is a layer formed using a composition containing a liquid crystal compound and a crosslinkable polymer, and the crosslinkable polymer has a hydroxyl group, the polarizing plate with an adhesive layer according to Claim 8.

11. The vertically aligned liquid crystal layer contains a photo-isomerizable compound on the surface opposite to the polymer film side, the polarizing plate with an adhesive layer according to Claim 8.

12. The angle formed by the absorption axis of the polarizer and the in-plane slow axis of the positive A plate is 45 ± 10°, The polarizing plate with an adhesive layer according to claim 1, wherein the in-plane retardation of the positive A plate at a wavelength of 550 nm is 120 to 170 nm.

13. The polarizing plate with an adhesive layer according to claim 1, wherein the polarizer and the positive A plate are laminated via a polyvinyl alcohol-based adhesive.

14. The polarizing plate with an adhesive layer according to claim 1, wherein the positive A plate is a layer obtained by curing a composition containing a polymerizable liquid crystal compound and a polymer having a group represented by the formula (1). Formula (1) *-B-(OR ｘ１ ) ２ R ｘ１ each independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and two Rs ｘ１ may be linked to each other via a linking group consisting of an alkylene linking group, an arylene linking group, or a combination thereof.

15. The polarizing plate with an adhesive layer according to claim 1, wherein the polarizer and the positive A plate are laminated via an adhesive layer formed by curing an ultraviolet curable adhesive.

16. The polarizing plate with an adhesive layer according to claim 8, wherein the polymer film includes a region A containing a liquid crystal-derived component contained in the vertically aligned liquid crystal layer, and the thickness of the region A is 20 to 200 nm.

17. A display device having the polarizing plate with an adhesive layer according to any one of claims 1 to 16.

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