Optical laminate and image display device

Abstract

Provided is an optical laminate having excellent reflection accuracy, i.e., uniformity of in-plane reflectance, even when the orientation of a linear polarizer is not uniform. The optical laminate includes a first linear polarizer and a phase difference layer laminate. The phase difference layer laminate has three or more phase difference layers, and at least three of the three or more phase difference layers are in-plane phase difference layers. The first linear polarizer is either an absorption-type polarizer or a reflection-type polarizer, and the in-plane standard deviation sigma of the visibility correction polarization degree Py of the first linear polarizer is 0.001% or more.

Description

Technical Field

[0001] This invention relates to optical laminates and image display devices. Background Technology

[0002] With the widespread use of optical devices such as image display devices, optical laminates containing polarizing components and phase retardation components are widely used in order to realize image display and improve the performance of image display. For example, in Patent Document 1, a circular polarizing plate that is excellent in suppressing the generation of cracks and uneven color tone when bent at high temperature is disclosed. The circular polarizing plate has a polarizer formed by curing a dichroic pigment and a polymeric liquid crystal compound in sequence, a λ / 2 liquid crystal phase retardation layer and a λ / 4 liquid crystal phase retardation layer.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2024-018946 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In recent years, new applications for image display devices have been developed, with the development of head-mounted displays for VR (Virtual Reality) and AR (Augmented Reality) technologies progressing rapidly. Research is underway into the use of these image display devices in various scenarios, with the aim of achieving high visibility. However, it is difficult to achieve perfectly uniform in-plane orientation of linear polarizers. For example, when applying the circular polarizer described in Patent Document 1 to a VR head-mounted display, there is room for improvement in visibility.

[0008] The present invention was made in view of the above-mentioned problems, and the object is to provide an optical laminate that has excellent reflection accuracy, i.e., uniformity of in-plane reflectivity, even when the orientation of the linear polarizer is not uniform.

[0009] Methods for solving problems

[0010] [1] An optical laminate comprising a first linear polarizer and a phase difference layer laminate,

[0011] The aforementioned phase difference layer stack has more than three phase difference layers.

[0012] At least three of the three or more phase retardation layers mentioned above are in-plane phase retardation layers.

[0013] The first linear polarizer mentioned above is either an absorption polarizer or a reflection polarizer.

[0014] The in-plane standard deviation σ of the visibility correction polarization degree Py of the first linear polarizer is greater than 0.001%.

[0015] [2] According to the optical laminate described in [1], the above-mentioned absorptive polarizer is a cured product of dichroic pigment and polymeric liquid crystal compound oriented.

[0016] [3] According to the optical laminate described in [1] or [2], wherein the indentation elastic modulus of the above-mentioned absorptive polarizer is 10000 MPa or less.

[0017] [4] An optical laminate according to any one of [1] to [3], wherein the in-plane phase difference layer satisfies the following condition,

[0018] 100nm≤Re(550)≤180nm.

[0019] [5] An optical laminate according to any one of [1] to [4], wherein the in-plane phase difference layer has inverse wavelength dispersion.

[0020] [6] An optical laminate according to any one of [1] to [5], wherein the in-plane phase difference layer satisfies the following condition,

[0021] Re(450) / Re(550)≤1.00.

[0022] [7] An optical stack according to any one of [1] to [6], wherein the aforementioned phase difference layer stack further has at least one phase difference layer in the thickness direction.

[0023] [8] According to the optical stack described in [7], the phase difference layer stack has a first in-plane phase difference layer, a second in-plane phase difference layer and a third in-plane phase difference layer in sequence from the first linear polarizer side, and the at least one layer having a phase difference in the thickness direction is disposed between the first in-plane phase difference layer and the second in-plane phase difference layer.

[0024] [9] According to the optical laminate described in [8], a cured layer of an active energy ray curable adhesive is disposed between the second inner phase difference layer and the third inner phase difference layer, and the refractive index of the cured layer is 1.50 or more.

[0025]

[10] An optical laminate according to any one of [1] to [9], wherein the phase difference layer laminate further has an adhesive layer disposed between at least one pair of the phase difference layers.

[0026]

[11] According to the optical laminate described in

[10] , at least one of the above-mentioned bonding layers is a cured layer of an active energy ray curable adhesive or an active energy ray curable adhesive.

[0027]

[12] According to the optical laminate described in

[10] , at least one of the above-mentioned bonding layers is a cured layer of an active energy ray curable adhesive.

[0028]

[13] An optical laminate according to any one of [1] to

[12] , wherein at least one pair of adjacent phase difference layers are laminated without an interlayer between the phase difference layers.

[0029]

[14] According to the optical laminate described in

[13] , the phase difference layer laminate further has at least one phase difference layer in the thickness direction, and the at least one pair of adjacent phase difference layers laminated without the intercalation of the bonding layer is a combination of an in-plane phase difference layer and a phase difference layer in the thickness direction.

[0030]

[15] An optical laminate according to any one of

[10] to

[14] , wherein the compressive elastic modulus of all bonding layers between the phase difference layers of the aforementioned phase difference layer laminate is 3 MPa or more.

[0031]

[16] An optical laminate according to any one of

[10] to

[15] , wherein the average thickness of all bonding layers present in the bonding layer of the phase difference layer laminate is 7 μm or less.

[0032]

[17] An optical laminate according to any one of [1] to

[16] , wherein the first linear polarizer is a reflective polarizer.

[0033]

[18] According to the optical stack described in [1] to

[17] , a second linear polarizer is further provided between the phase difference stack and the first linear polarizer or on the side opposite to the phase difference stack relative to the first linear polarizer, wherein the second linear polarizer is either an absorption type polarizer or a reflection type polarizer.

[0034]

[19] An image display device comprising the optical laminate and image display element described in [1] to

[18] .

[0035] Invention Effects

[0036] According to the present invention, an optical laminate can be provided that can achieve high reflection accuracy even when the orientation of the linear polarizer is non-uniform. Attached Figure Description

[0037] Figure 1This is a cross-sectional view of an optical laminate, an example of the first embodiment.

[0038] Figure 2 This is a cross-sectional view of an optical laminate, an example of the first embodiment.

[0039] Figure 3 This is a cross-sectional view of an optical laminate, an example of the first embodiment.

[0040] Figure 4 This is a cross-sectional view of an optical laminate, an example of the first embodiment.

[0041] Figure 5 This is a diagram showing the relationship between the transmission axis 120TA of the linear polarizer in the optical laminate and the slow axis 300SA of the λ / 2 section and the slow axis 400SA of the λ / 4 section.

[0042] Figure 6 This is a cross-sectional view of an optical laminate, an example of the second embodiment.

[0043] Figure 7 This is a cross-sectional view of an optical laminate, an example of the second embodiment.

[0044] Figure 8 This is a cross-sectional view of an optical laminate, another example of the second embodiment.

[0045] Figure 9 This is a cross-sectional view of an optical laminate, another example of the second embodiment. Detailed Implementation

[0046] The embodiments of the present invention will be described below. First, the terminology used in the present invention will be explained.

[0047] [Phase difference layer]

[0048] The phase difference layer of this invention refers to an optical medium with birefringence. Birefringence refers to the different optical properties resulting from a difference in refractive index greater than 0.02 in at least two of three orthogonal directions.

[0049] [Refractive index of the phase décor layer]

[0050] The refractive indices in the three orthogonal directions of the retardation layer are referred to as nx, ny, and nz. nx represents the principal refractive index in the direction parallel to the plane of the retardation layer within the refractive index ellipsoid formed by the retardation layer. ny represents the refractive index in the direction parallel to the plane of the retardation layer and orthogonal to the nx direction within the refractive index ellipsoid formed by the retardation layer. nz represents the refractive index in the direction perpendicular to the plane of the retardation layer within the refractive index ellipsoid formed by the retardation layer.

[0051] [In-plane retardation and thickness direction retardation of the retardation layer]

[0052] Delay is a physical quantity that represents the anisotropy of a phase difference layer. There are in-plane delay Re and thickness-direction delay Rth.

[0053] The in-plane delay Re(λ) at wavelength λnm is represented by Equation (1). In Equation (1), d represents the thickness (nm) of the phase difference layer.

[0054] Re(λ)=(nx-ny)×d···(1)

[0055] The thickness directional delay Rth(λ) at wavelength λnm is represented by equation (2). In equation (2), d is the same as d in equation (1) as the thickness (nm) of the phase difference layer.

[0056] Rth(λ)=-{nz-(nx+ny) / 2}×d···(2)

[0057] [Phase difference layer stack]

[0058] Optical stacks with multiple phase difference layers are sometimes referred to as phase difference layer stacks.

[0059] The embodiments of the present invention will now be described with reference to the accompanying drawings. Identical or equivalent parts are labeled with the same symbols in the drawings, and repeated descriptions are omitted. The scale of the drawings may not necessarily match the description.

[0060] (Optical laminate 10 (circular polarizer) of the first embodiment)

[0061] like Figure 1 As shown, the optical laminate 10 of the first embodiment includes a first polarizing plate 100A, an adhesive layer D (200), a phase difference layer laminate 600, and an adhesive layer Z (700).

[0062] (First polarizing plate 100A)

[0063] The first polarizing plate 100A includes a first linear polarizer 120A. It has a first protective layer 110, the first linear polarizer 120A, and a second protective layer 130. It should be noted that although the first protective layer 110 and the second protective layer 130 are arbitrary, it is preferred to have at least one or both of the first protective layer and the second protective layer.

[0064] (First linear polarizer 120A)

[0065] The first linear polarizer 120A has the function of selectively transmitting linearly polarized light in a certain direction from unpolarized light rays such as natural light. The first linear polarizer is an absorption type polarizer.

[0066] The polarization performance of a linear polarizer can be measured using a spectrophotometer. For example, in the visible light wavelength range of 380 nm to 780 nm, a spectrophotometer equipped with a prism polarizer can be used to measure the transmittance (T1) along the transmission axis (orientation perpendicular direction) and the transmittance (T2) along the absorption axis or reflection axis using the two-beam method. The polarization performance in the visible light range can be calculated as follows: the single-unit transmittance and degree of polarization at each wavelength are calculated using the following equations (Equation 1) and (Equation 2), and then visibility correction is performed using the 2-degree field of view (C light source) of JIS Z 8701. Thus, the visibility-corrected single-unit transmittance (Ty) and visibility-corrected degree of polarization (Py) are calculated. Furthermore, based on the same measured transmittance, using the isochromatic function of the C light source, the chromaticity a* and b* in the L*a*b* (CIE) color system can be calculated. From this, the hue of a single linear polarizer (single-unit hue), the hue of linear polarizers arranged in parallel (parallel hue), and the hue of linear polarizers arranged orthogonally (orthogonal hue) can be obtained. The closer the a* and b* values ​​are to 0, the closer the hue is to neutral.

[0067] Monomer transmittance (%) = (T1 + T2) / 2 ··· (Equation 1)

[0068] Degree of polarization (%) = (T1-T2) / (T1+T2)×100 ···(Equation 2)

[0069] It should be noted that, regarding the degree of polarization, the same measurement can be performed on a laminate containing a protective layer or the like on a linear polarizer, as described in the embodiments described later, and the obtained degree of polarization can be set as the degree of polarization of the linear polarizer. Specifically, if the linear polarizer does not contain a layer with an in-plane phase difference on at least one side, the degree of polarization of the linear polarizer can be measured by setting the incident surface during measurement to the aforementioned at least one surface.

[0070] In this embodiment, the in-plane standard deviation σ of the visibility-corrected polarization degree Py of the first linear polarizer 120A is 0.001% or more. If this standard deviation σ is less than 0.001%, the linear polarizer has high orientation, and therefore, even when used as a circular polarizer by stacking it with an arbitrary phase difference layer as shown in the reference example described later, the reflection accuracy is not easily reduced. The standard deviation σ can be 0.002% or more, 0.003% or more, 0.004% or more, or 0.005% or more. In addition, the standard deviation σ is usually 0.100% or less. If the standard deviation σ is too large, it will cause disorder in the image display when used in an image display device. The unit of the visibility-corrected polarization degree Py used in the calculation of the standard deviation σ is %.

[0071] The standard deviation is calculated based on measurement data from five points at least 5 cm apart in the plane. Specifically, it can be calculated using the method described in the examples below.

[0072] The visibility-corrected polarization degree Py of the first linear polarizer is typically 80% or higher, preferably 90% or higher, more preferably 95% or higher, even more preferably 98% or higher, particularly preferably 99% or higher, and if it is 99.9% or higher, it can be suitable for use in liquid crystal displays. Increasing the visibility-corrected polarization degree Py of the first linear polarizer is advantageous in improving the anti-reflective function of the optical laminate. If the visibility-corrected polarization degree Py is less than 80%, the anti-reflective function when used as an anti-reflective film may not be achieved.

[0073] The higher the transmittance Ty of the visibility correction monomer in the first linear polarizer, the greater the clarity when displaying white. From the relationship between (Equation 1) and (Equation 2), it can be seen that excessively increasing the monomer transmittance leads to a decrease in polarization degree. Therefore, it is preferably 30% or more and 60% or less, more preferably 35% or more and 55% or less, further preferably 38% or more and 50% or less, even more preferably 40% or more and 48% or less, even more preferably 41% or more and 47% or less, and particularly preferably 41.5% or more and 46% or less. If the transmittance Ty of the visibility correction monomer is too high, the polarization degree Py becomes too low, resulting in insufficient anti-reflective function when used as an anti-reflective film.

[0074] (Absorption polarizer)

[0075] Absorption polarizers have a transmission axis and an absorption axis. Examples of absorption polarizers include films obtained by uniaxial stretching of polymers such as PVA containing iodine and organic dichroic dyes (hereinafter also called "polarizers"), and optically anisotropic layers formed by orienting dichroic dyes and polymeric liquid crystal compounds (hereinafter also called "polarizing films").

[0076] The indentation modulus of an absorptive polarizer is, for example, 10,000 MPa or less, preferably 9,900 MPa or less, more preferably 9,000 MPa or less, even more preferably 3,000 MPa or less, even more preferably 2,000 MPa or less, and particularly preferably 1,000 MPa or less. Alternatively, it can be 100 MPa or more. Particularly when the absorptive polarizer is a polarizing film, it is typically 100 MPa or more and 15,000 MPa or less, and can be 5,000 MPa or more and 10,000 MPa or less. Furthermore, when the linear polarizer is a polarizing film, it is typically 100 MPa or more and 3,000 MPa or less, and can be 100 MPa or more and 2,000 MPa or less, and can be 300 MPa or more and 1,000 MPa or less. The indentation modulus of the linear polarizer is the indentation modulus measured along a cross-section of the transmission perimeter.

[0077] For the indentation modulus of elasticity mentioned in this specification, either the DMT modulus or the JKR modulus of elasticity is used. The DMT modulus is obtained by evaluating the mechanical properties of the cross-section of the specimen using a scanning probe microscope (SPM), and by analyzing the pull-back process of the force curve based on the theory (DMT theory) developed by Derjaguim-Muller-Toporov et al. The JKR modulus is obtained by analysis based on the JKR (Johnson-Kendall-Roberts) theory. The indentation modulus of elasticity is measured at a temperature of 24°C.

[0078] The values ​​at 41% humidity were obtained by measuring according to the method described in the examples below. It should be noted that, as described in the examples, the DMT elastic modulus of each layer of the evaluation sample was measured. The DMT elastic modulus was used for layers with a DMT elastic modulus of 1000 MPa or more, and the JKR elastic modulus was used for layers with a DMT elastic modulus of less than 1000 MPa.

[0079] <Polarizer>

[0080] A film obtained by uniaxially stretching a polymer such as polyvinyl alcohol (PVA) film while impregnated with iodine or an organic dichroic dye can typically be manufactured through the following steps: uniaxial stretching of the PVA film; adsorption of the dichroic dye by dyeing the PVA film with iodine or other dichroic dyes; treatment of the PVA film with the adsorbed dichroic dye using a crosslinking agent such as boric acid aqueous solution; and washing with water after treatment with the crosslinking agent such as boric acid aqueous solution. The polarizing film may contain a crosslinking agent.

[0081] The thickness of the polarizer is typically 30 μm or less, preferably 18 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. This thickness is typically 1 μm or more, for example, 5 μm or more.

[0082] The in-plane standard deviation σ of the visibility correction polarization degree Py of a polarizer is typically greater than 0 and less than 0.100%. This standard deviation σ can sometimes increase due to various manufacturing conditions, such as stretching ratio, tension, and drying temperature. Furthermore, for polarizers with high transmittance of the visibility correction element, there is a tendency for the standard deviation σ to increase.

[0083] <Polarizing film>

[0084] Considering the ability to arbitrarily control hue, the ability to achieve significant thinning, and the non-shrinkage property due to the absence of thermal stretching relaxation, polarizing films, i.e., optically anisotropic layers formed from polymers containing dichroic pigments and polymeric liquid crystal compounds, are superior.

[0085] The in-plane standard deviation σ of the visibility correction polarization degree Py of a polarizing film is typically 0.001 to 0.100%. Due to the in-plane inhomogeneity of its orientation constraint force, polarizing films are particularly prone to becoming non-uniform in orientation compared to polarizers, and the aforementioned standard deviation σ tends to be higher.

[0086] A polarizing film is formed by coating a polarizing film forming composition onto an alignment film formed on a substrate as needed, and aligning the dichroic pigments contained in the polarizing film forming composition. The polarizing film has a thickness of 0.1 μm or more and 5 μm or less, more preferably 0.3 μm or more and 4 μm or less, and even more preferably 0.5 μm or more and 3 μm or less. If the film thickness is below this range, the necessary light absorption may not be obtained, and if the film thickness is above this range, the alignment constraint force provided by the alignment film is reduced, and there is a tendency for alignment defects to easily occur. Furthermore, the polarizing film forming composition may further include solvents, photopolymerization initiators, photosensitizers, polymerization inhibitors, leveling agents, and adhesion enhancers.

[0087] For an optically anisotropic layer obtained by horizontally aligning a dichroic pigment and a polymeric liquid crystal compound relative to a substrate surface, a dichroic ratio (the ratio of absorbance A1(λ) in the orientation direction to absorbance A2(λ) in the direction perpendicular to the orientation plane for light with wavelength λnm) is preferably 7 or higher, more preferably 20 or higher, and even more preferably 40 or higher. The higher this value, the better the absorption selectivity of the polarizer. Although it also depends on the type of dichroic pigment, in the case of a liquid crystal cured film obtained by curing in the state of a nematic liquid crystal phase, it is about 5 to 10.

[0088] By mixing two or more dichroic pigments with different absorption wavelengths, polarizing films of various hues can be produced, including polarizing films that absorb light across the entire visible light spectrum. By creating polarizing films with such absorption properties, applications can be expanded to a wide range of uses.

[0089] A polarizing film can be formed on an alignment film. The alignment film possesses an alignment-restricting force that orients the polymerizable liquid crystal compound in a desired direction, making it easy to obtain a polarizing sheet with excellent alignment precision by coating the alignment film with a polarizing film forming composition. Preferably, the alignment film has solvent resistance that prevents dissolution due to coating of the aforementioned polarizing film forming composition, and heat resistance in heat treatments for solvent removal and orientation of the polymerizable liquid crystal compound. From the viewpoints of the accuracy and quality of the alignment angle, and the water resistance and bending resistance of the polarizing plate containing the alignment film, a photoaligning film is preferred. A photoaligning film is also advantageous because the direction of the alignment-restricting force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light. The alignment film can be disposed on the visible side of the polarizing film or on the side opposite to the visible side.

[0090] Polarizing films can have anti-diffusion layers on one or two sides. By having anti-diffusion layers adjacent to or close to the polarizing film, the diffusion of dichroic pigments from the polarizing film to other layers can be effectively suppressed. When anti-diffusion layers are located on both sides of the polarizing film, they can be the same or different.

[0091] As an anti-diffusion layer, there are no particular limitations as long as the layer has the anti-diffusion function of dichroic pigments. For example, a layer formed by a resin composition containing a water-soluble polymer or a layer formed by a curable composition containing an active energy ray curable resin can be cited.

[0092] <Polarizing films; polymeric liquid crystal compounds>

[0093] A polymerizable liquid crystal compound is a compound that possesses polymerizable groups and liquid crystal properties (hereinafter also referred to as a polymerizable liquid crystal). Polymerizable groups refer to groups that participate in polymerization reactions, preferably photopolymerizable groups. Here, photopolymerizable groups refer to groups that can participate in polymerization reactions through active free radicals, acids, etc., generated by a photopolymerization initiator described later. Examples of polymerizable groups include vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, oxyethylene oxide (Oxiranyl group), and oxetane. Among these, acryloyloxy, methacryloyloxy, ethoxy, oxyethylene oxide, and oxetane are preferred, and methacryloyloxy or acryloyloxy are more preferred. The liquid crystal properties can be thermotropic or lyotropic; when mixed with dichroic pigments described later, thermotropic liquid crystals are preferred. The polymerizable liquid crystal compound can be a monomer or a polymer that has polymerized into dimers or higher.

[0094] When the polymerizable liquid crystal compound is a thermotropic liquid crystal, it can be either a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. From the viewpoint of exhibiting high dichroism, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and if it is a higher-order smectic phase, it is even more preferable from the viewpoint of high performance. Among these, higher-order smectic liquid crystal compounds forming smectic B, smectic D, smectic E, smectic F, smectic G, smectic H, smectic I, smectic J, smectic K, or smectic L phases are more preferable, and higher-order smectic liquid crystal compounds forming smectic B, smectic F, or smectic I phases are even more preferable. If the liquid crystal phase formed by the polymerizable liquid crystal is one of these higher-order smectic phases, a polarizing film with higher polarization performance can be manufactured. In addition, polarizing films with such high polarization performance can obtain Bragg peaks from higher-order structures such as hexagonal phases and crystalline phases in X-ray diffraction measurements. These Bragg peaks are peaks from the periodic structure of molecular orientation, and films with period intervals of 3 to 6 Å can be obtained. From the viewpoint of obtaining higher polarization characteristics, it is preferable that the polarization film of the present invention comprises a polymer of the polymeric liquid crystal oriented in a smectic phase.

[0095] As a polymerizable liquid crystal compound, one type can be used alone, or two or more can be used in combination. The polymerizable liquid crystal composition containing other compounds described later may also contain other polymerizable liquid crystal compounds besides the polymerizable liquid crystal compound, provided that the effect of the present invention is not impaired. However, from the viewpoint of obtaining a polarizing film with high orientation order, the proportion of the polymerizable liquid crystal compound to the total mass of all polymerizable liquid crystal compounds contained in the polymerizable liquid crystal composition is preferably 51% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0096] The content of the polymeric liquid crystal compound in the polarization film forming composition of the present invention is preferably 40 to 99.9% by mass relative to the solid content of the polymeric liquid crystal composition, more preferably 60 to 99% by mass, and even more preferably 70 to 99% by mass. If the content of the polymeric liquid crystal compound is within the above range, there is a tendency for the orientation of the polymeric liquid crystal compound to increase. It should be noted that, in this specification, the term "solid content" refers to the total amount of components after removing the solvent from the polymeric liquid crystal composition.

[0097] <Polarizing film; dichroic pigment>

[0098] A dichroic pigment is a pigment whose absorbance differs along its long axis from that along its short axis. Preferably, a dichroic pigment possesses the property of absorbing visible light, and more preferably, it has a maximum absorption wavelength (λMAX) in the range of 380–680 nm. Examples of such dichroic pigments include acridine pigments, oxazine pigments, anthocyanins, naphthalene pigments, azo pigments, and anthraquinone pigments, with azo pigments being preferred. Examples of azo pigments include monoazo, diazo, triazo, tetraazo, and succinylazo pigments, with diazo and triazo pigments being preferred. Dichroic pigments can be used alone or in combination. To achieve absorption across the entire visible light spectrum, it is preferable to use two or more dichroic pigments in combination, and more preferably, three or more dichroic pigments in combination.

[0099] Examples of azo dyes include compounds represented by formula (I) (hereinafter sometimes referred to as "compound (I)").

[0100] T 1 -A 1 (-N=NA) 2 ) p -N=NA 3 -T 2 (I)

[0101] In formula (I), A 1 and A 2 and A 3 Each can independently represent a 1,4-phenylene group that may have a substituent, a naphth-1,4-diyl group that may have a substituent, a benzoic acid phenyl ester group that may have a substituent, a piracene group that may have a substituent, or a divalent heterocyclic group that may have a substituent. T 1 and T 2 These are electron-withdrawing or electron-donating groups, located at a position substantially 180° relative to the azo bond plane. p represents an integer from 0 to 4. When p is 2 or higher, each A... 2They can be the same or different. Within the visible absorption range, -N=N- bonds can be replaced by -C=C-, -COO-, -NHCO-, or -N=CH- bonds.

[0102] Regarding the content of the dichroic pigment (which is the total amount when multiple pigments are included), from the viewpoint of obtaining good light absorption characteristics, it is typically 1 to 60 parts by mass relative to 100 parts by mass of the polymeric liquid crystal compound, preferably 1 to 40 parts by mass, and more preferably 1 to 20 parts by mass. If the content of the dichroic pigment is lower than this range, light absorption is insufficient and adequate polarization performance cannot be obtained; if it is higher than this range, it may hinder the orientation of liquid crystal molecules.

[0103] (The structure of the first polarizing plate with an absorptive polarizer)

[0104] The first polarizing plate 100A comprises a first protective layer, a first linear polarizer, and a second protective layer. The first and second protective layers are arbitrary; at least one or both may be present.

[0105] (First protective layer 110 and second protective layer 130)

[0106] The first and second protective layers each function to protect the surface of the first linear polarizer. The thermoplastic resin film used as the protective layer can be a monomeric film, in which case the thermoplastic resin film is laminated onto the first linear polarizer, with an adhesive layer (described later) sandwiched between it as needed. Alternatively, the protective layer can be a thermoplastic resin layer or a curable resin layer. The first linear polarizer and the thermoplastic resin film can be directly laminated together. "Direct lamination" here includes both lamination using the self-adhesive properties of the thermoplastic resin film onto the first linear polarizer and lamination with an adhesive layer or bonding agent sandwiched between them. To improve adhesion to the first linear polarizer, the thermoplastic resin film can be surface-treated (e.g., corona treatment), or a thin layer such as a primer layer (also called an easy-to-adhere layer) can be formed. It should be noted that while the first and second protective layers are optional, it is preferable to have at least one or both of the first and second protective layers.

[0107] As thermoplastic resin films, resin films with excellent properties such as transparency, mechanical strength, thermal stability, water resistance, isotropy, and tensile strength can be used. The resin film can be a thermoplastic resin film. Specific examples of such resins include cellulose-based resins such as triacetyl cellulose; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone-based resins; polysulfone-based resins; polycarbonate-based resins; polyamide-based resins such as nylon and aromatic polyamides; polyimide-based resins; polyolefin-based resins such as polyethylene, polypropylene, and ethylene / propylene copolymers; cyclic polyolefin-based resins with cyclic and norbornene structures (also called norbornene-based resins); (meth)acrylic resins such as polymethyl methacrylate; polyarylate-based resins; polystyrene-based resins; polyvinyl alcohol-based resins; and mixtures thereof. Protective films made of this material are readily available on the market. In this specification, "(meth)acrylic" means either acrylic or methacrylic.

[0108] The thickness of the thermoplastic resin film is preferably 0.1 μm to 60 μm, more preferably 0.5 μm to 40 μm, and even more preferably 1 μm to 30 μm.

[0109] The thermoplastic resin film can be used in a configuration where it is visible relative to the first linear polarizer. Therefore, surface treatments such as hard coating, anti-reflective treatment, anti-adhesion treatment, and anti-glare treatment can be applied to the thermoplastic resin film as needed. And / or, treatments can be applied to the thermoplastic resin film to improve visibility when viewed through polarized sunglasses (typically, to impart (elliptical) polarization or ultra-high phase difference). By implementing such treatments, excellent visibility can be achieved even when viewing the display image through polarized lenses such as polarized sunglasses. Therefore, such a polarizing plate can also be suitable for use in image display devices that can be used outdoors.

[0110] The aforementioned thermoplastic resin film may contain any appropriate additives depending on the intended purpose. Examples of additives include, for instance, hindered phenolic, phosphorus-based, and sulfur-based antioxidants; light stabilizers, UV absorbers, weather stabilizers, and heat stabilizers; reinforcing materials such as glass fiber and carbon fiber; near-infrared absorbers; flame retardants such as tris(dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; colorants such as inorganic pigments, organic pigments, and dyes; organic and inorganic fillers; resin modifiers; plasticizers; lubricants; and phase difference reducers. The types, combinations, and amounts of these additives can be appropriately determined based on the intended purpose and desired characteristics.

[0111] Furthermore, to impart desired surface optical properties or other characteristics, the first protective layer may be a multi-layered first protective layer having a coating layer (surface treatment layer) further provided on the outside of the thermoplastic resin film. Specific examples of the surface treatment layer include a hard coating layer, an anti-glare layer, an anti-reflective layer, an antistatic layer, and an anti-fouling layer. The method of forming the surface treatment layer is not particularly limited, and known methods may be used. The surface treatment layer may be formed on one side or both sides of the thermoplastic resin film.

[0112] When the protective layer is a thermoplastic resin layer or a curable resin layer as described later, the first linear polarizer can be in direct contact with the protective layer without the adhesive layer being sandwiched between them.

[0113] For example, a composition containing a thermoplastic resin is coated onto a support substrate, dried as needed, and the resulting thermoplastic resin layer with the support substrate sandwiched between an adhesive layer is then bonded to a first linear polarizer, whereby the support substrate is peeled off. This allows a thermoplastic resin layer as a protective layer to be laminated onto the first linear polarizer (Method 1). Alternatively, if the protective layer is a thermoplastic resin layer, the composition can be directly coated onto the surface of the first linear polarizer and dried as needed, thus forming a thermoplastic resin layer. In this case, the first linear polarizer is in direct contact with the protective layer without sandwiching an adhesive layer (Method 2). However, if the composition contains a solvent, Method 1 is preferred because it facilitates the stable formation of a thermoplastic resin layer with a sufficiently reduced solvent content.

[0114] The protective layer can be a cured resin layer containing a cured product of a curable resin. Examples of curable resins include thermosetting resins and active energy curable resins, such as (meth)acrylic resins, epoxy resins, oxetane resins, urethane resins, (meth)acrylic urethane resins, and melamine resins. The cured resin layer containing a cured product of a curable resin can be formed by applying a composition containing a curable resin onto a support substrate, drying it as needed, and then heating or irradiating it with active energy rays such as visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, gamma rays, or electron beams. The resulting cured resin layer with the support substrate is then bonded to a first linear polarizer, with an adhesive layer sandwiched between it as needed. The support substrate is then peeled off, thereby allowing the cured resin layer serving as a protective layer to be laminated onto the first linear polarizer.

[0115] (Between the first polarizer 100A and the phase difference layer stack 600)

[0116] Between the first polarizer 100A and the phase difference layer stack 600, any optical component may be present, but preferably an adhesive layer or bonding agent layer (hereinafter referred to as "adhesive layer D").

[0117] (Adhesive layer (adhesive layer D) 200)

[0118] The bonding layer can be an adhesive layer (also known as a pressure-sensitive adhesive) or an adhesive layer.

[0119] (Adhesive layer)

[0120] As the adhesive composition forming the adhesive layer, conventionally known adhesive compositions with excellent optical transparency can be used without particular limitation. For example, adhesive compositions with base polymers such as acrylic resins, urethane resins, silicone resins, and polyvinyl ether resins can be used. Additionally, active energy radiation-cured adhesive compositions and thermosetting adhesive compositions can also be used. Among these, adhesive compositions with acrylic resins as base polymers that exhibit excellent transparency, adhesion, re-peelability, weather resistance, and heat resistance are particularly suitable.

[0121] The adhesive composition may further include crosslinking agents, silane compounds, antistatic agents, etc.

[0122] [(Meth)acrylic resins]

[0123] The (meth)acrylate resin contained in the adhesive composition is preferably a polymer (hereinafter also referred to as "(meth)acrylate polymer") with a main component derived from a structural unit of a (meth)acrylate alkyl ester represented by the following formula (I) (also referred to as "structural unit (I)"). For example, it contains 50 or more parts by mass relative to 100 parts by mass of the (meth)acrylate resin structural unit.

[0124] It should be noted that in this specification, the term "(meth)acrylic resin" means either an acrylic resin or a methacrylic resin, and the "(meth)" in "(meth)acrylate" and the like has the same meaning.

[0125] [Chemistry 1]

[0126]

[0127] [In the formula, R] 10 R represents a hydrogen atom or a methyl group. 20 The alkyl group represents an alkyl group having 1 to 20 carbon atoms. This alkyl group can have any of the following structures: straight-chain, branched, or cyclic. The hydrogen atoms of this alkyl group can be substituted with alkoxy groups having 1 to 10 carbon atoms.

[0128] Examples of (meth)acrylates represented by formula (I) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-and isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, tert-butyl (meth)acrylate, etc. Specific examples of alkyl acrylates containing alkoxy groups include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate, etc. Preferably, it contains n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate, and particularly preferably contains n-butyl (meth)acrylate.

[0129] (Meth)acrylate polymers may contain structural units derived from monomers other than structural unit (I). There may be one or more structural units derived from other monomers. Examples of other monomers that may be included in (meth)acrylate polymers include monomers with polar functional groups, monomers with aromatic groups, and acrylamide monomers.

[0130] Examples of monomers with polar functional groups include (meth)acrylates. Examples of polar functional groups include hydroxyl groups; carboxyl groups; substituted or unsubstituted amino groups substituted with alkyl groups having 1 to 6 carbon atoms; heterocyclic groups such as epoxy groups.

[0131] The content of structural units derived from monomers having polar functional groups in the (meth)acrylate polymer is preferably 10 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, even more preferably 0.5 parts by mass or more and 5 parts by mass or less, and particularly preferably 1 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylate polymer.

[0132] As monomers containing aromatic groups, they have one (meth)acryloyl group and one or more aromatic rings (e.g., benzene ring, naphthalene ring, etc.) within the molecule. Examples of (meth)acrylates containing phenyl, phenoxyethyl, or benzyl groups are examples. By including these structural units, the whitening phenomenon of polarizers that occurs in high temperature and high humidity environments can be suppressed.

[0133] The content of structural units derived from monomers having aromatic groups in the (meth)acrylate polymer is preferably 20 parts by mass or less, more preferably 4 parts by mass or more and 20 parts by mass or less, and even more preferably 4 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylate polymer.

[0134] Examples of acrylamide monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, and N-(2-methylpropoxymethyl)acrylamide. By incorporating these structural units, the exudation of additives such as antistatic agents described later can be suppressed.

[0135] In addition, as structural units derived from other monomers besides structural unit (I), they may include structural units derived from styrene monomers, structural units derived from vinyl monomers, structural units derived from monomers having multiple (meth)acryloyl groups within the molecule, etc.

[0136] The weight-average molecular weight (hereinafter also referred to as "Mw") of the (meth)acrylic resin (1) is preferably 500,000 to 2,500,000. If the weight-average molecular weight is 500,000 or more, the durability of the adhesive layer under high temperature and high humidity conditions can be improved. If the weight-average molecular weight is 2,500,000 or less, the workability when coating a coating liquid containing the adhesive composition becomes good. The molecular weight distribution (Mw / Mn), expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (hereinafter also referred to as "Mn"), is usually 2 to 10. The terms "weight-average molecular weight" and "number-average molecular weight" in this specification are polystyrene conversion values ​​determined by gel permeation chromatography (GPC).

[0137] When preparing a 20% by mass solution by dissolving a (meth)acrylic resin in ethyl acetate, the viscosity at 25°C is preferably 20 Pa·s or less, more preferably 0.1 to 15 Pa·s. If the viscosity of the (meth)acrylic resin at 25°C is within the above range, it contributes to improving the durability and reprocessability of the polarizer containing the adhesive layer formed using the resin. The above viscosity can be measured using a Brookfield viscometer.

[0138] The glass transition temperature (Tg) of the (meth)acrylic resin is, for example, -60 to 20°C, preferably -50 to 15°C, more preferably -45 to 10°C, and even more preferably -40 to 0°C. It should be noted that the glass transition temperature can be determined using a differential scanning calorimeter (DSC).

[0139] (Meth)acrylic resins may contain two or more (meth)acrylate polymers. Examples of such (meth)acrylate polymers include (meth)acrylate polymers with a lower molecular weight, where the structural unit (I) derived from the above-mentioned (meth)acrylate is the main component and the weight-average molecular weight is in the range of 50,000 to 300,000.

[0140] (Meth)acrylic resins can generally be manufactured using known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. In the manufacture of (meth)acrylic resins, polymerization is usually carried out in the presence of a polymerization initiator. The amount of polymerization initiator used is typically 0.001 to 5 parts by mass relative to 100 parts by mass of all monomers constituting the (meth)acrylic resin. (Meth)acrylic resins can also be manufactured using methods that polymerize using active energy rays such as ultraviolet light.

[0141] [Cross-linking agent]

[0142] The adhesive composition preferably includes a crosslinking agent. Commonly used crosslinking agents can be cited as examples (e.g., isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.), and isocyanate compounds are preferred, especially from the viewpoints of the usable time of the adhesive composition, the crosslinking speed and the durability of the polarizer.

[0143] Isocyanate compounds are compounds having at least two isocyanate groups (-NCO) within their molecules. Specifically, examples include toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, phenylenediamine diisocyanate, hydrogenated phenylenediamine diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. Additionally, examples include adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, as well as dimers and trimers of these isocyanate compounds. Combinations of two or more isocyanate compounds are also possible.

[0144] The proportion of the crosslinking agent relative to 100 parts by weight of the (meth)acrylic resin is, for example, 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, and more preferably 0.1 to 1 parts by weight.

[0145] [Silane compounds]

[0146] The adhesive composition may further contain silane compounds.

[0147] Examples of silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0148] In addition, silane compounds may contain oligomers derived from the aforementioned silane compounds.

[0149] The content of silane compounds in the adhesive composition is typically 0.01 to 10 parts by weight relative to 100 parts by weight of (meth)acrylic resin, preferably 0.05 to 5 parts by weight. If the content of silane compounds is 0.01 parts by weight or more, there is a tendency to improve the adhesion between the adhesive layer and the adherend; if the content is 10 parts by weight or less, there is a tendency to suppress the exudation of silane compounds from the adhesive layer.

[0150] <Antistatic agent>

[0151] The adhesive composition may further include an antistatic agent. Known antistatic agents can be cited as examples, with ionic antistatic agents being particularly suitable. As the cationic component constituting the ionic antistatic agent, organic and inorganic cations can be cited. As organic cations, pyridinium cations, imidazolium cations, ammonium cations, sulfonium cations, phosphonium cations, etc., can be cited. As inorganic cations, alkali metal cations such as lithium cations, potassium cations, sodium cations, cesium cations, etc., and alkaline earth metal cations such as magnesium cations, calcium cations, etc., can be cited. As the anionic component constituting the ionic antistatic agent, it can be either inorganic or organic anions; however, from the perspective of superior antistatic performance, anionic components containing fluorine atoms are preferred. As an anionic component containing fluorine atoms, hexafluorophosphate anion (PF6) can be cited. - ), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N] - ], bis(fluorosulfonyl)imide anion [(FSO2)2N - Anions, etc.

[0152] From the perspective of excellent antistatic properties and long-term stability of the adhesive composition, an ionic antistatic agent that is solid at room temperature is preferred.

[0153] The content of the antistatic agent relative to 100 parts by weight of the (meth)acrylic resin is, for example, 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, and more preferably 1 to 7 parts by weight.

[0154] The adhesive composition may contain one or more additives such as UV absorbers, solvents, crosslinking catalysts, tackifying resins (tackifiers), and plasticizers. Additionally, it is useful to incorporate UV-curable compounds into the adhesive composition and cure it by irradiating it with UV light after the adhesive layer is formed, thus creating a harder adhesive layer.

[0155] An adhesive layer can be formed, for example, by dissolving or dispersing the above-mentioned adhesive composition in a solvent to prepare an adhesive composition containing a solvent, then applying it to the surface of the layer to which the adhesive layer is to be formed, and then drying it.

[0156] The thickness of the adhesive layer is typically 0.1–30 μm, preferably 1–30 μm, and more preferably 3–25 μm.

[0157] (Adhesive layer)

[0158] The adhesive layer can be formed from an adhesive composition.

[0159] Examples of adhesive compositions include aqueous adhesive compositions and curable adhesive compositions that are cured by heating or irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Examples of aqueous adhesive compositions include compositions obtained by dissolving polyvinyl alcohol resin or urethane resin in water as the main component, and compositions obtained by dispersing polyvinyl alcohol resin or urethane resin in water as the main component. Aqueous adhesive compositions may further contain curing components such as polyaldehydes, melamine compounds, zirconium dioxide compounds, zinc compounds, glyoxal compounds, water-soluble epoxy resins, and crosslinking agents. Examples of water-based adhesive compositions include those described in Japanese Patent Application Publication No. 2010-191389, Japanese Patent Application Publication No. 2011-107686, Japanese Patent Application Publication No. 2020-172088, and Japanese Patent Application Publication No. 2005-208456.

[0160] The preferred curable adhesive composition is an active energy ray curable adhesive composition that contains a curable (polymerizable) compound as the main component and is cured by irradiation with active energy rays. Examples of active energy ray curable adhesive compositions include cationic polymeric adhesive compositions containing a cationic polymeric compound as the curing compound, free radical polymeric adhesive compositions containing a free radical polymeric compound as the curing compound, and mixed adhesive compositions containing both cationic polymeric compounds and free radical polymeric compounds as curing compounds.

[0161] Cationic polymerizable compounds are compounds or oligomers that undergo cationic polymerization and are cured by irradiation or heating with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Specifically, examples include epoxy compounds, oxetane compounds, and vinyl compounds.

[0162] Examples of epoxy compounds include alicyclic epoxy compounds such as 3,4-epoxycyclohexanecarboxylic acid 3',4'-epoxycyclohexylmethyl ester (compounds having one or more epoxy groups bonded to an alicyclic ring within the molecule); aromatic epoxy compounds such as bisphenol A diglycidyl ether (compounds having both an aromatic ring and an epoxy group within the molecule); and aliphatic epoxy compounds such as 2-ethylhexyl glycidyl ether and 1,4-butanediol diglycidyl ether (compounds having at least one ethylene oxide ring bonded to an aliphatic carbon atom within the molecule).

[0163] Examples of oxetane compounds include 3-ethyl-3-{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane, which are compounds having one or more oxetane rings in the molecule.

[0164] The cationic polymerization adhesive composition preferably includes a cationic polymerization initiator. The cationic polymerization initiator can be a thermal cationic polymerization initiator or a photocationic polymerization initiator. Examples of cationic polymerization initiators include aromatic diazonium salts such as phenyldiazohexafluoroantimonate; aromatic iodonium salts such as diphenyliodonium tetra(pentafluorophenyl)borate; aromatic sulfonium salts such as triphenylsulfonium hexafluorophosphate; and iron-aromatic complexes such as xylene-cyclopentadienyl iron(II)hexafluoroantimonate. The content of the cationic polymerization initiator is typically 0.1 to 10 parts by weight relative to 100 parts by weight of the cationic polymerization compound. Two or more cationic polymerization initiators may be included.

[0165] Examples of cationic polymerizable adhesive compositions include those described in Japanese Patent Application Publication No. 2016-126345, International Publication No. 2019 / 10315, and Japanese Patent Application Publication No. 2021-113969.

[0166] Free radical polymerizable compounds are compounds or oligomers that undergo free radical polymerization and solidify through irradiation or heating by active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Specifically, examples include compounds with olefinic unsaturated bonds. Examples of compounds with olefinic unsaturated bonds include (meth)acrylic acid compounds with one or more (meth)acryloyl groups in the molecule, and vinyl compounds with one or more vinyl groups in the molecule.

[0167] Examples of (meth)acrylic acid compounds include (meth)acrylate monomers having at least one (meth)acryloyloxy group in the molecule, (meth)acrylamide monomers, and (meth)acrylic acid oligomers having at least two (meth)acryloyl groups in the molecule obtained by reacting two or more compounds containing functional groups. In this specification, (meth)acryloyl group means either an acryloyl group or a methacryloyl group.

[0168] Free radical polymerization adhesive compositions preferably include a free radical polymerization initiator. The free radical polymerization initiator can be a thermal free radical polymerization initiator or a photo-free radical polymerization initiator. Examples of free radical polymerization initiators include acetophenone-based initiators such as acetophenone and 3-methylacetophenone; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin ether-based initiators such as benzoin propyl ether and benzoin ethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; and xanthones and fluorenones. The content of the free radical polymerization initiator is typically 0.1 to 10 parts by weight relative to 100 parts by weight of the free radical polymerizable compound. Two or more free radical polymerization initiators may be included.

[0169] Examples of free radical polymerizable adhesive compositions include those described in Japanese Patent Application Publication No. 2016-126345, Japanese Patent Application Publication No. 2016-153474, and International Publication No. 2017 / 183335.

[0170] The active energy ray curable adhesive composition may contain additives such as ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow modifiers, plasticizers, defoamers, antistatic agents, leveling agents, and solvents, as needed.

[0171] The adhesive composition and adhesive layer are suitable for containing silicone-based or fluorine-based leveling agents. The leveling agent content in the adhesive composition and adhesive layer is preferably 0.001 to 2 parts by weight relative to 100 parts by weight of the solid components.

[0172] The bonding of the polarizing plate 100A and the phase retardation layer laminate 600 using an adhesive layer can be performed by applying an adhesive composition to at least one bonding surface selected from the bonding surface of the polarizing plate 100A and the bonding surface of the phase retardation layer laminate 600, overlapping the two with the adhesive composition coating layer sandwiched between them, pressing them together from above and below using a bonding roller or the like, drying the adhesive layer, curing it by irradiating it with active energy rays or by heating it.

[0173] Before forming the adhesive layer, at least one bonding surface selected from the bonding surface of the polarizing plate 100A and the bonding surface of the phase difference layer laminate 600 can be subjected to easy bonding treatments such as saponification, corona treatment, plasma treatment, primer treatment, and anchor coating treatment.

[0174] When forming the coating layer of the adhesive composition, various coating methods can be used, such as die coating machine, comma-type doctor blade coating machine, gravure coating machine, wire rod coating machine, and scraper coating machine.

[0175] The light intensity during irradiation with active energy rays is determined according to each component of the active energy ray-cured adhesive composition, and is not particularly limited, but is preferably 10 mW / cm². 2 Above and 1000mW / cm 2 The following should be noted: the irradiation intensity is preferably within the wavelength range effective for activating photocationic polymerization initiators or photoradical polymerization initiators. It is preferable to irradiate once or multiple times with such an intensity, and to set the cumulative light dose to 10 mJ / cm². 2 The above is more preferably set to 100 mJ / cm. 2 Above and 2000mJ / cm 2 the following.

[0176] There are no particular limitations on the light source used for the polymerization and curing of active energy radiation-cured adhesive compositions. Examples include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, gallium lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0177] The thickness of the adhesive layer formed by the aqueous adhesive composition is, for example, 5 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less, and can be 0.001 μm or more, 0.01 μm or more, preferably 0.05 μm or more.

[0178] The thickness of the adhesive layer formed by the active energy ray curable adhesive composition can be, for example, 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, and can be 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more.

[0179] (Indentation elastic modulus of bonding layer D)

[0180] The compressive modulus of the adhesive layer D is not particularly limited; however, from the viewpoint of suppressing color changes under high-temperature conditions, the compressive modulus of the adhesive layer D is preferably 3 MPa or more, more preferably 5 MPa or more, further preferably 8 MPa or more, and even more preferably 10 MPa or more. It can also be 50 MPa or more, 100 MPa or more, 500 MPa or more, 1000 MPa or more, 2000 MPa or more, or 2500 MPa or more. The compressive modulus of the adhesive layer D is typically 6000 MPa or less.

[0181] (In-plane average refractive index of bonding layer D)

[0182] The in-plane average refractive index of the bonding layer D is not particularly limited; however, from the viewpoint of suppressing the reduction of the anti-reflective function of the circular polarizer, the in-plane average refractive index of the bonding layer D is preferably 1.40 or higher, more preferably 1.45 or higher, and even more preferably 1.50 or higher. It is typically 1.70 or lower.

[0183] It should be noted that, in this specification, the in-plane average refractive index of each bonding layer is the refractive index at a wavelength of 589 nm, which can be measured using an Abbe refractometer, KOBRA-WR (manufactured by Oji Measurement Equipment Co., Ltd.), or similar instruments. Specifically, for example, it can be measured according to the method described in the embodiments described later. The in-plane average refractive index of each plane of the phase retardation layer described later can also be measured in the same way.

[0184] In this specification, the in-plane average refractive index of each bonding layer is the refractive index at a wavelength of 589 nm, which can be measured using an Abbe refractometer, a KOBRA-WR (manufactured by Oji Measurement Equipment Co., Ltd.), or similar instruments. Specifically, it can be measured, for example, according to the method described in the embodiments described later. The in-plane average refractive index of each phase retardation layer described later can also be measured in the same way.

[0185] (Phase difference layer stack 60°)

[0186] The phase retardation layer stack 600 has a λ / 2 portion 300 and a λ / 4 portion 400. Preferably, the phase retardation layer stack 600 has the λ / 2 portion 300 and the λ / 4 portion 400 sequentially from the side of the first linear polarizer 120A. Alternatively, an adhesive layer (called adhesive layer B) may be sandwiched between the λ / 2 portion 300 and the λ / 4 portion 400.

[0187] (λ / 2 parts 300)

[0188] The λ / 2 section 300 has the function of imparting a phase difference of λ / 2 to the incident light of wavelength λ.

[0189] The λ / 2 section 300 has two or more in-plane retardation layers (retardation layers) 310. The slow axes of each in-plane retardation layer 310 are approximately aligned. "Approximately aligned" means within a range of ±5°.

[0190] The λ / 2 part 300 can have at least one thickness direction phase difference layer (phase difference layer) 320 in addition to two or more in-plane phase difference layers 310. It is suitable to have two thickness direction phase difference layers 320 or one thickness direction phase difference layer.

[0191] In the λ / 2 section 300, at least one thickness-direction phase retardation layer 320 may be disposed between pairs of in-phase phase retardation layers 310. Particularly in the λ / 2 section 300, from the viewpoint of tilt visibility as an optical stack, it is suitable to have thickness-direction phase retardation layers 320 and to arrange them between pairs of in-phase phase retardation layers 310. It should be noted that the thickness-direction phase retardation layer 320 disposed between pairs of in-phase phase retardation layers 310 may be one or more.

[0192] Specifically, an example of the stacked structure of the phase difference layer of the λ / 2 part 300 recorded from the side of the first linear polarizer is shown below.

[0193] In-plane phase retardation layer 310 / Thickness direction phase retardation layer 320 / Thickness direction phase retardation layer 320 / In-plane phase retardation layer 310

[0194] In-plane phase retardation layer 310 / Thickness direction phase retardation layer 320 / In-plane phase retardation layer 310

[0195] Here, the in-plane phase difference layer 310 on the side of the first linear polarizer is sometimes referred to as the first in-plane phase difference layer, and the in-plane phase difference layer 310 on the side opposite to the first linear polarizer is sometimes referred to as the second in-plane phase difference layer.

[0196] [In-plane phase difference layer 310]

[0197] The in-plane phase retardation layer 310 includes a layer that embodies an in-plane phase retardation. In this specification, a layer that embodies an in-plane phase retardation means a layer that has birefringence in a direction parallel to the plane of the phase retardation layer, and more specifically, a layer that has different optical properties due to a difference between nx and ny greater than 0.02.

[0198] The layer that embodies the in-plane phase difference can be a layer formed by stretching or other means of a thermoplastic resin film, or it can be an optically anisotropic layer (hereinafter also referred to as "phase difference film") formed by a polymer formed by oriented polymeric liquid crystal compound.

[0199] The in-plane retardation layer 310 is suitable as a retardation film (hereinafter also referred to as a "λ / 4 plate") to impart a phase difference of approximately λ / 4 to incident light of wavelength λ. Approximately λ / 4 means the range of one-sixth to one-third of the wavelength λ. The in-plane phase difference of the λ / 4 plate can be expressed as follows.

[0200] 100nm≤Re(550)≤180nm

[0201] The suitable range for the Re(550) value of the λ / 4 plate is preferably 100 nm or more and 160 nm or less, more preferably 110 nm or more and 150 nm or less. The in-plane phase difference value of the in-plane phase difference layer 310 can be adjusted by the thickness of the layer embodying the in-plane phase difference. Since the in-plane phase difference value is determined by the following equation (4), in order to obtain the desired in-plane phase difference value (Re(λ)), it is only necessary to adjust Δn(λ) and the film thickness d. The thickness of the layer embodying the in-plane phase difference can be measured using an interferometric thickness gauge, a laser microscope, or a probe-type thickness gauge. It should be noted that when the layer embodying the in-plane phase difference is a layer formed by polymerizing a polymeric liquid crystal, Δn(λ) depends on the molecular structure of the polymeric liquid crystal compound described later.

[0202] Re(λ)=d×Δn(λ)…(4)

[0203] (In the formula, Re(λ) represents the in-plane phase difference at wavelength λnm, d represents the film thickness, and Δn(λ) represents the birefringence at wavelength λnm.)

[0204] The in-plane phase difference layer 310 can be either positive wavelength dispersion or reverse wavelength dispersion, but it is suitable to have reverse dispersion.

[0205] An in-plane phase difference layer 310 with inverse wavelength dispersion (hereinafter also referred to as "inverse dispersion") satisfies the following equation (8), and can further satisfy equation (9).

[0206] Re(450) / Re(550)≤1.00···(8)

[0207] 1.00≤Re(650) / Re(550)···(9)

[0208] If the "Re(450) / Re(550)" of the in-plane phase retardation layer 310 is greater than 1.0, the light leakage on the short-wavelength side of the optical stack having the in-plane phase retardation layer increases. Preferably, it is 0.7 or more and 1.0 or less, more preferably 0.80 or more and 0.95 or less, even more preferably 0.80 or more and 0.93 or less, and particularly preferably 0.82 or more and 0.92 or less. Regarding the value of "Re(450) / Re(550)", when the layer embodying the in-plane phase retardation is formed by polymerizing a polymeric liquid crystal, it can be arbitrarily adjusted by adjusting the mixing ratio of the polymeric liquid crystal compound, the stacking angle of the multiple optically anisotropic layers, and the phase difference value.

[0209] The in-plane phase retardation layer 310 can also be a positive A-plate. The positive A-plate is a phase retardation layer in which the refractive index in each direction satisfies the relationship of equation (3). By default, the slow axis of the positive A-plate is parallel to nx, and ny≈nz means that the difference between ny and nz is less than 0.02.

[0210] nx>ny≈nz ····(3)

[0211] When the positive A plate is a λ / 4 plate, the in-plane delay Re(λ) and the thickness direction delay Rth(λ) of the positive A plate at a wavelength of λnm have a relationship with Equation (5) derived from Equations (1), (2), and (3).

[0212] Rth(λ)=0.5×Re(λ)···(5)

[0213] The thickness retardation Rth(550) at a wavelength of 550 nm for the λ / 4 plate can be within the range of Equation (6).

[0214] 50nm≤Rth(550)≤90nm ···(6)

[0215] The suitable range of values ​​for Rth (550) is preferably 50 nm or more and 80 nm or less, and more preferably 55 nm or more and 75 nm or less.

[0216] When the layer embodying the in-plane phase difference is a stretched film, its thickness is typically less than 80 μm, preferably 5 μm or more and 70 μm or less, more preferably 10 μm or more and 60 μm or less. When the layer embodying the in-plane phase difference is a layer formed by polymerizing a polymeric liquid crystal, its thickness is typically 10 μm or less, preferably 5 μm or less, more preferably 0.3 μm or more and 3 μm or less. The layer embodying the in-plane phase difference is preferably a coating layer formed by polymerizing one or more polymeric liquid crystals.

[0217] (Indentation elastic modulus of the in-plane phase difference layer)

[0218] The indentation modulus of the in-plane retardation layer 310 is not particularly limited; however, from the viewpoint of suppressing wrinkles after bending, it is suitable to be 1000 MPa or more, more suitable to be 1500 MPa, and even more preferably 2000 MPa or more. Alternatively, it is typically 10000 MPa or less. The indentation modulus of the in-plane retardation layer is the indentation modulus measured along a section along the slow axis.

[0219] (In-plane average refractive index of the in-plane phase retardation layer)

[0220] In one embodiment of the present invention, the in-plane average refractive index of the in-plane retardation layer 310 is preferably 1.50 to 1.70, and more preferably 1.55 to 1.65. If the in-plane average refractive index of the in-plane retardation layer 310 is within the above range, it is particularly easy to improve the light reflection suppression effect at the interface with the bonding layer B. The in-plane average refractive index of the in-plane retardation layer can be controlled by the types and combinations of the components constituting the in-plane retardation layer.

[0221] <Phase difference film>

[0222] From the perspective of thinning and the ability to arbitrarily design wavelength dispersion characteristics, it is preferable to coat a composition containing a polymeric liquid crystal compound (hereinafter also referred to as "phase retardation film forming composition") onto a transparent substrate to form an optically anisotropic layer formed by a polymer in which the polymeric liquid crystal compound is oriented. Furthermore, the phase retardation film forming composition may further include a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, and an adhesion enhancer, etc.

[0223] Phase retardation films are typically formed by coating a phase retardation film forming composition onto an alignment film formed on a substrate, and then polymerizing the polymeric liquid crystal compound contained in the phase retardation film forming composition. Phase retardation films are generally cured films obtained by aligning the polymeric liquid crystal compound. To generate a phase retardation within the observation plane, a cured film obtained by polymerizing the polymeric groups of the polymeric liquid crystal compound in a horizontally aligned state relative to the substrate surface is required. In this case, if the polymeric liquid crystal compound is rod-shaped, only the positive A-plate is needed; if the polymeric liquid crystal compound is disk-shaped, only the negative A-plate is needed.

[0224] <Compositions for forming phase retardation films; polymeric liquid crystal compounds>

[0225] The polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition of the present invention refers to a liquid crystal compound having polymerizable groups, particularly photopolymerizable groups. Conventionally known polymerizable liquid crystal compounds can be used as such compounds. A photopolymerizable group refers to a reactive species generated by a photopolymerization initiator, such as a group capable of participating in a polymerization reaction via an active free radical, acid, etc. Examples of photopolymerizable groups include vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloxy, ethylene oxide, and oxetane. Acryloyloxy, methacryloxy, ethoxy, and oxetane are preferred, and acryloyloxy is more preferred. The liquid crystal can be a thermotropic liquid crystal or a lyotropic liquid crystal; however, from the perspective of controlling a dense film thickness, a thermotropic liquid crystal is preferred. Furthermore, the phase-ordered structure in the thermotropic liquid crystal can be a nematic liquid crystal or a smectic liquid crystal. Additionally, it can be a rod-shaped liquid crystal or a disc-shaped liquid crystal. Polymerizable liquid crystal compounds can be used alone or in combination of two or more.

[0226] From the viewpoint of exhibiting reverse wavelength dispersion, liquid crystals with a T-shaped or H-shaped mesocrystalline structure that further exhibit birefringence in the direction perpendicular to the molecular long axis are preferred as polymerizable liquid crystal compounds. From the viewpoint of obtaining stronger dispersion, T-shaped liquid crystals are more preferred. Specifically, compounds represented by the following formula (I) can be cited as examples of T-shaped liquid crystal structures.

[0227] [Chemistry 2]

[0228]

[0229] In formula (I), Ar represents a divalent aromatic group that may have substituents. Preferably, the divalent aromatic group contains at least one of nitrogen, oxygen, or sulfur atoms. When the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups can be bonded to each other by single bonds, -CO-O-, -O-, or other divalent linking groups.

[0230] G 1 and G 2 Each of these can be independently represented as a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted by a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and the carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be replaced by an oxygen atom, a sulfur atom, or a nitrogen atom.

[0231] L 1 L2 B 1 and B 2 Each is an independent linking group that is either a single bond or divalent.

[0232] k and l each independently represent integers from 0 to 3, satisfying the relation 1 ≤ k + l. Here, in the case of 2 ≤ k + l, B 1 and B 2 G 1 and G 2 They can be the same as each other, or they can be different.

[0233] E 1 and E 2 Each alkadiyl group independently represents an alkadiyl group with 1 to 17 carbon atoms. Here, the hydrogen atoms in the alkadiyl group can be replaced by halogen atoms, and the -CH2- in the alkadiyl group can be replaced by -O-, -S-, or -COO-. In the case of multiple -O-, -S-, or -COO- groups, they are not adjacent to each other. P 1 and P 2 Each of them independently represents a polymeric group or a hydrogen atom, with at least one being a polymeric group.

[0234] G 1 and G 2 Each of the following is preferably 1,4-phenylene diel that can be substituted with at least one substituent selected from halogen atoms and alkyl groups having 1 to 4 carbon atoms, or 1,4-cyclohexane diel that can be substituted with at least one substituent selected from halogen atoms and alkyl groups having 1 to 4 carbon atoms; more preferably 1,4-phenylene diel substituted with methyl, unsubstituted 1,4-phenylene diel, or unsubstituted 1,4-trans-cyclohexane diel; and particularly preferably unsubstituted 1,4-phenylene diel or unsubstituted 1,4-trans-cyclohexane diel.

[0235] In addition, it is preferable that there are multiple Gs. 1 and G 2 At least one of them is a divalent alicyclic hydrocarbon group, and more preferably it is with L 1 or L 2 bonded G 1 and G 2 At least one of them is a divalent alicyclic hydrocarbon group.

[0236] L 1 and L 2 Each is preferably a single bond, an alkylene group having 1 to 4 carbon atoms, and is -O-, -S-, or -R. a1 OR a2 -、-R a3 COOR a4 -、-R a5 OCOR a6 -、-Ra7 OC = OOR a8 -、-N=N-、-CR c =CR d - or -C≡C-. Here, R a1 ~R a8 Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, R c and R d Represents an alkyl group or hydrogen atom having 1 to 4 carbon atoms. L 1 and L 2 Each independently is more preferably a single bond, -OR a2-1 -、-CH2-、-CH2CH2-、-COOR a4-1 -or-OCOR a6-1 -. Here, R a2-1 R a4-1 R a6-1 Each can independently represent any one of a single bond, -CH2-, or -CH2CH2-. L 1 and L 2 Each of these can be further preferred independently as a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, or -OCO-.

[0237] B 1 and B 2 Each is preferably a single bond, an alkylene group having 1 to 4 carbon atoms, and is -O-, -S-, or -R. a9 OR a10 -、-R a11 COOR a12 -、-R a13 OCOR a14 -or-R a15 OC = OOR a16 -. Here, R a9 ~R a16 Each can independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B 1 and B 2 Each independently is more preferably a single bond, -OR a10-1 -、-CH2-、-CH2CH2-、-COOR a12-1 -or-OCOR a14-1 -. Here, R a10-1 R a12-1 R a14-1 Each can independently represent any one of a single bond, -CH2-, or -CH2CH2-. B 1 and B 2 Each of these can be further preferred independently as a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or -OCOCH2CH2-.

[0238] From the viewpoint of exhibiting inverse wavelength dispersion, k and l are preferably in the range of 2 ≤ k + l ≤ 6, preferably k + l = 4, and more preferably k = 2 and l = 2. If k = 2 and l = 2, a symmetrical structure is formed, which is therefore preferred.

[0239] Preferred E 1 and E 2 Each is independently an alkyldiyl group having 1 to 17 carbon atoms, more preferably an alkyldiyl group having 4 to 12 carbon atoms.

[0240] As P 1 or P 2 Examples of polymerizable groups include epoxy, vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, ethylene oxide, and oxetane. Acryloyloxy, methacryloyloxy, ethoxy, and oxetane are preferred, and acryloyloxy is more preferred.

[0241] Ar preferably has at least one selected from aromatic hydrocarbon rings that may have substituents, aromatic heterocycles that may have substituents, and electron-withdrawing groups. Examples of such aromatic hydrocarbon rings include benzene rings, naphthyl rings, and anthracene rings, with benzene rings and naphthyl rings being preferred. Examples of such aromatic heterocycles include furan rings, benzofuran rings, pyrrole rings, indole rings, thiophene rings, benzothiophene rings, pyridine rings, pyrazine rings, pyrimidine rings, triazole rings, triazine rings, pyrrolidine rings, imidazole rings, pyrazole rings, thiazole rings, benzothiazole rings, thienothiazole rings, oxazole rings, benzoxazole rings, and phenanthroline rings. Among these, a thiazole ring, a benzothiazole ring, or a benzofuran ring is preferred, and a benzothiazole group is more preferred. Furthermore, when Ar contains a nitrogen atom, it is preferable that the nitrogen atom has a π electron.

[0242] In formula (I), N is the total number of π electrons contained in the divalent aromatic group represented by Ar. π Preferably, the value is 8 or more, more preferably 10 or more, even more preferably 14 or more, and particularly preferably 16 or more. Furthermore, it is preferably 30 or less, more preferably 26 or less, and even more preferably 24 or less.

[0243] As an aromatic group represented by Ar, the following groups can be suitably listed, for example.

[0244] [Chemistry 3]

[0245]

[0246] In equations (Ar-1) to (Ar-23), * indicates a connecting part, Z 0 Z 1 and Z2 Each can independently represent a hydrogen atom, a halogen atom, an alkyl group (1-12 carbon atoms), a cyano group, a nitro group, an alkyl sulfinyl group (1-12 carbon atoms), an alkyl sulfonyl group (1-12 carbon atoms), a carboxyl group, a fluoroalkyl group (1-12 carbon atoms), an alkoxy group (1-6 carbon atoms), an alkyl thio group (1-12 carbon atoms), an N-alkylamino group (1-12 carbon atoms), an N,N-dialkylamino group (2-12 carbon atoms), an N-alkylaminosulfonyl group (1-12 carbon atoms), or an N,N-dialkylaminosulfonyl group (2-12 carbon atoms).

[0247] Q 1 and Q 2 Each is represented independently - CR 2’ R 3’ -、-S-、-NH-、-NR 2’ -、-CO- or -O-, R 2’ and R 3’ Each can be independently represented by a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0248] J 1 and J 2 Each can be used to represent a carbon atom or a nitrogen atom independently.

[0249] Y 1 and Y 2 Each can be independently represented as a substituted aromatic hydrocarbon group or an aromatic heterocyclic group.

[0250] W 1 and W 2 Each can independently represent a hydrogen atom, cyano group, methyl group, or halogen atom, and m represents an integer from 0 to 6.

[0251] As Y 1 and Y 2 The aromatic hydrocarbon group in the compound can include phenyl, naphthyl, anthraceneyl, phenanthryl, biphenyl, and other aromatic hydrocarbon groups with 6 to 20 carbon atoms, with phenyl and naphthyl being preferred, and phenyl being more preferred. As aromatic heterocyclic groups, can include furanyl, pyrroleyl, thiopheneyl, pyridyl, thiazolyl, benzothiazolyl, and other aromatic heterocyclic groups with 4 to 20 carbon atoms containing at least one heteroatom such as a nitrogen atom, oxygen atom, or sulfur atom, with furanyl, thiopheneyl, pyridyl, thiazolyl, and benzothiazolyl being preferred.

[0252] Y 1 and Y 2 Each can be independently a substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group. A polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. A polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

[0253] Z 0 Z1 and Z 2 Each of the following is preferably composed of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms. 0 More preferably, it is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, Z 1 and Z 2 More preferably, hydrogen atoms, fluorine atoms, salt atoms, methyl groups, and cyano groups.

[0254] Q 1 and Q 2 Preferred types are -NH-, -S-, and -NR. 2’ -、-O-,R 2’ Hydrogen atoms are preferred. Among them, -S-, -O-, and -NH- are particularly preferred.

[0255] From the perspective of molecular stability, formulas (Ar-6) and (Ar-7) are preferred among formulas (Ar-1) to (Ar-23).

[0256] In equations (Ar-16) to (Ar-23), Y 1 It can bond with the nitrogen atom and Z 0 Together, they form an aromatic heterocyclic group. Examples of aromatic heterocyclic groups that Ar can possess include pyrrole rings, imidazole rings, pyrrololine rings, pyridine rings, pyrazine rings, pyrimidine rings, indole rings, quinoline rings, isoquinoline rings, purine rings, and pyrrolidine rings. This aromatic heterocyclic group may have substituents. Additionally, Y... 1 It can bond with the nitrogen atom and Z 0 Together, these are the aforementioned substituted polycyclic aromatic hydrocarbon groups or polycyclic aromatic heterocyclic groups. Examples include benzofuran rings, benzothiazole rings, and benzoxazole rings.

[0257] In polymerizable liquid crystal compounds, compounds with a maximum absorption wavelength of 300–400 nm are preferred. When a polymerizable liquid crystal composition contains a photoinitiator, polymerization and gelation of the polymerizable liquid crystal compound may be accelerated during long-term storage. However, if the maximum absorption wavelength of the polymerizable liquid crystal compound is 300–400 nm, the generation of reactive species from the photoinitiator and the acceleration of polymerization and gelation caused by these reactive species can be effectively suppressed even when exposed to ultraviolet light during storage. Therefore, this is advantageous from the perspective of the long-term stability of the polymerizable liquid crystal composition, as it improves the orientation and uniformity of the resulting cured liquid crystal film. It should be noted that the maximum absorption wavelength of the polymerizable liquid crystal compound can be determined using a UV-Vis spectrophotometer in a solvent. This solvent is one that can dissolve the polymerizable liquid crystal compound, such as chloroform.

[0258] Regarding the content of the polymeric liquid crystal compound in the polymeric liquid crystal composition, relative to 100 parts by weight of the solid component of the polymeric liquid crystal composition, it is, for example, 70 to 99.5 parts by weight, preferably 80 to 99 parts by weight, more preferably 85 to 98 parts by weight, and even more preferably 90 to 95 parts by weight. If the content of the polymeric liquid crystal compound is within the above range, it is advantageous from the viewpoint of the orientation of the resulting liquid crystal cured film. It should be noted that, in this specification, the term "solid component of the polymeric liquid crystal composition" refers to all components remaining after removing volatile components such as organic solvents from the polymeric liquid crystal composition.

[0259] [Thickness-direction phase difference layer 320]

[0260] The thickness-direction phase retardation layer 320 is a layer that imparts a thickness-direction phase difference to the incident light. Specifically, it can be a positive C-plate. There are no special restrictions on the positive C-plate as long as it is anisotropic along the thickness direction. Without tilting or cholesterol orientation, it is a phase retardation layer in which the refractive indices in each direction satisfy the relationship of equation (7). By default, the slow axis of the positive C-plate is parallel to nz, and nx≈ny means that the difference between nx and ny is less than 0.02.

[0261] nx≈ny<nz ···(7)

[0262] The thickness direction delay Rth(550) of the thickness direction phase difference layer 320 can satisfy equation (13).

[0263] The thickness direction phase difference Rth (550) imparted by the entire at least one thickness direction phase difference layer 320 disposed between one pair of in-phase phase difference layers 310 can be -240 to -30 nm, -240 to -50 nm, -240 to -60 nm, preferably -200 to -80 nm, more preferably -180 to -100 nm, even more preferably -160 to -120 nm, and typically -140 nm.

[0264] For example, when a thickness-direction phase difference layer 320 is disposed between two pairs of in-phase phase difference layers 310, the thickness-direction phase difference Rth (550) of the thickness-direction phase difference layer 320 can be -240 to -30 nm, -240 to -50 nm, -240 to -60 nm, preferably -200 to -80 nm, more preferably -180 to -100 nm, even more preferably -160 to -120 nm, and typically -140 nm. The thickness of the thickness-direction phase difference layer 320 can be 0.6 to 6 μm.

[0265] Additionally, for example, such as Figure 1 As shown, when two thickness direction phase difference layers 320 are disposed between two pairs of in-phase phase difference layers 310, the thickness direction phase difference Rth (550) of each thickness direction phase difference layer 320 can be -120 to -15nm, -120 to -25nm, -120 to -30nm, preferably -100 to -40nm, more preferably -90 to -50nm, even more preferably -80 to -60nm, and typically can be -70μm. The thickness of each thickness direction phase difference layer 320 can be 0.3 to 3μm.

[0266] It should be noted that when multiple thickness-direction phase difference layers 320 are arranged between one pair of in-phase phase difference layers 310, the thickness-direction phase difference Rth of these thickness-direction phase difference layers can be the same or different from each other.

[0267] The in-plane phase difference value Re(550) at a wavelength of 550nm in the thickness direction phase difference layer 320 is typically in the range of 0 to 10nm, preferably in the range of 0 to 5nm.

[0268] (Indentation elastic modulus of the phase difference layer in the thickness direction)

[0269] The indentation elastic modulus of the phase difference layer 320 in the thickness direction is not particularly limited; however, from the viewpoint of suppressing wrinkles after bending, it is suitable to be 1000 MPa or more, more suitable to be 1500 MPa or more, further preferably 2000 MPa or more, and even more preferably 2500 MPa or more. In addition, it is usually 10000 MPa or less.

[0270] (In-plane average refractive index of the phase décor layer in the thickness direction)

[0271] In one embodiment of the present invention, the in-plane average refractive index of the thickness-direction retardation layer 320 is preferably 1.50 to 1.70, and more preferably 1.50 to 1.60. The in-plane average refractive index of the thickness-direction retardation layer can be controlled by the types and combinations of the components constituting the in-plane retardation layer.

[0272] The positive C plate is preferably a coating layer formed by polymerizing one or more polymeric liquid crystal compounds. More preferably, it is a rod-shaped polymeric liquid crystal compound.

[0273] Examples of rod-shaped polymeric liquid crystals include compounds represented by formulas (I), (II), (III), (IV), (V), or (VI).

[0274] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I)

[0275] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II)

[0276] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III)

[0277] P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV)

[0278] P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V)

[0279] P11-B11-E11-B12-A11-B13-A12-F11 (VI)

[0280] (In the formula, A12 to A14 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, and E12 is synonymous with E11. F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxyl group, a hydroxymethyl group, a formyl group, a sulfonyl group (-SO3H), a carboxyl group, an alkoxy carbonyl group having 1 to 10 carbon atoms, or a halogen atom. The -CH2- group constituting the alkyl group and the alkoxy group can be replaced with -O-.)

[0281] Regarding the content of the polymeric liquid crystal compound in the polymeric liquid crystal composition, relative to 100 parts by mass of the solid component of the polymeric liquid crystal composition, it is preferably 70 to 99.5 parts by mass, more preferably 80 to 99 parts by mass, and even more preferably 85 to 98 parts by mass, and further preferably 90 to 95 parts by mass. If the content of the polymeric liquid crystal compound is within the above range, it is advantageous from the viewpoint of the orientation of the resulting liquid crystal cured film. It should be noted that, in this specification, the term "solid component of the polymeric liquid crystal composition" refers to all components remaining after removing volatile components such as organic solvents from the polymeric liquid crystal composition.

[0282] (Orientation film)

[0283] The alignment film described in this specification has an alignment constraint force that causes the polymeric liquid crystal compound to align in a desired direction.

[0284] When the in-plane phase retardation layer 310 and the thickness-direction phase retardation layer 320 are layers obtained by curing polymerizable liquid crystals, the in-plane phase retardation layer and the thickness-direction phase retardation layer are typically formed on an alignment film provided on a substrate. Regarding the alignment film, it can be removed together with the substrate after the phase retardation layer is formed, or it can remain there. Therefore, the alignment film can be independently provided on one side of the in-plane phase retardation layer and the thickness-direction phase retardation layer in this embodiment. The alignment film can be disposed on the side of the first linear polarizer 120A relative to each phase retardation film, or it can be disposed on the side opposite to the first linear polarizer 120A.

[0285] Alignment films facilitate the alignment of polymeric liquid crystal compounds. The alignment state varies depending on the properties of the alignment film and the polymeric liquid crystal compound, and their combination can be arbitrarily chosen. Horizontal alignment films can be used when fabricating in-plane retardation layers, while vertical alignment films can be used when fabricating thickness-direction retardation layers.

[0286] Regarding the orientation constraint force, when the orientation film is formed from an orientation polymer, it can be arbitrarily adjusted using surface conditions and friction conditions; when it is formed from a photo-oriented polymer, it can be arbitrarily adjusted using polarized light irradiation conditions, etc. Furthermore, liquid crystal orientation can also be controlled by selecting the surface tension, liquid crystal properties, and other physical properties of the polymerizable liquid crystal compound.

[0287] As an alignment film formed between a substrate and an optically anisotropic layer, an alignment film that is insoluble in the solvent used when forming the optically anisotropic layer on the alignment film and has heat resistance for solvent removal and heat treatment for liquid crystal alignment is preferred. Examples of alignment films include alignment films containing an alignment polymer, photoalignment films, groove alignment films, and stretched films stretched along the alignment direction. In the case of application to long-length roll films, photoalignment films are preferred from the perspective of easy control of the alignment direction.

[0288] The thickness of the alignment film is typically in the range of 10 nm to 5000 nm, preferably in the range of 10 nm to 1000 nm, and more preferably in the range of 30 nm to 300 nm.

[0289] Examples of orientation polymers used in friction-oriented films include polyamides with intramolecular amide bonds, gelatin-like polymers, polyimides with intramolecular imide bonds and their hydrolysates such as polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylates. Polyvinyl alcohol is preferred. These orientation polymers can be used alone or in combination of two or more.

[0290] As a method of friction, one example is to bring a film of an oriented polymer into contact with a friction roller wound with a friction cloth and rotating. The film of the oriented polymer is formed on the surface of a substrate by coating an oriented polymer composition onto a substrate and then annealing it.

[0291] Photoalignment films contain polymers, oligomers, or monomers with photoreactive groups. Photoalignment films can acquire orientation confinement forces by irradiating them with polarized light. The direction of the orientation confinement force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light, making photoalignment films a more preferable option.

[0292] A photoreactive group is a group that generates liquid crystal alignment capability through light irradiation. Specifically, it is a photoreactive group that undergoes orientation-inducing or isomerizing reactions, dimerization reactions, photocrosslinking reactions, or photodecomposition reactions of molecules generated by light irradiation, thus becoming the origin of liquid crystal alignment capability. Among these photoreactive groups, groups that undergo dimerization or photocrosslinking reactions are preferred from the viewpoint of excellent alignment. As a photoreactive group capable of undergoing the reactions described above, a group having unsaturated bonds, especially double bonds, is preferred, and a group having at least one selected from carbon-carbon double bonds (C=C bonds), carbon-nitrogen double bonds (C=N bonds), nitrogen-nitrogen double bonds (N=N bonds), and carbon-oxygen double bonds (C=O bonds) is more preferred.

[0293] Examples of photoreactive groups with C=C bonds include vinyl, polyene, linyl, linazolyl, stilbene, chalcone, and cinnamoyl groups. Chalcone and cinnamoyl groups are preferred from the perspective of easily controllable reactivity and orientation-restricting forces during photoorientation. Examples of photoreactive groups with C=N bonds include groups with structures such as aromatic Schiff bases and aromatic hydrazones. Examples of photoreactive groups with N=N bonds include azophenyl, azonaphthyl, aromatic heterocyclic azo, diazo, and formazanyl groups, with azobenzene oxide as the basic structure. Examples of photoreactive groups with C=O bonds include benzophenone, coumarin, anthraquinone, and maleimide groups. These groups may have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid, and haloalkyl groups.

[0294] When irradiating with polarized light, the polarized light can be irradiated directly from the film surface, or it can be irradiated from the substrate side, allowing the polarized light to pass through before irradiation. Furthermore, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the irradiated polarized light is preferably a wavelength in the region where the photoreactive groups of the polymer or monomer having photoreactive groups can absorb light energy. Specifically, UV (ultraviolet light) in the wavelength range of 250–400 nm is particularly preferred. Examples of light sources for this polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, KrF, ArF, and other ultraviolet lasers, with high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps being more preferred. These lamps are preferred because ultraviolet light with a wavelength of 313 nm has a high luminous intensity. Polarized light can be irradiated by passing the light emitted from the above-mentioned light source through a suitable polarizer. As the polarizer, polarizing filters, Glasgow Thomson prisms, Glasgow Taylor prisms, and wire-grid polarizers can be used.

[0295] (Layered structure and bonding layer of λ / 2 part 300)

[0296] In the λ / 2 section 300, a pair of phase retardation layers, such as those between in-plane phase retardation layers 310, those between phase retardation layers 320 in the thickness direction, and those between in-plane phase retardation layers 310 and phase retardation layers 320 in the thickness direction, can be in direct contact. Alternatively, only one or two alignment films may be sandwiched between these phase retardation layers. Furthermore, an adhesive layer (hereinafter referred to as adhesive layer A) may be sandwiched between these phase retardation layers. When adhesive layer A is sandwiched, an alignment film may or may not exist between the phase retardation layers and adhesive layer A.

[0297] In the λ / 2 section, it is preferable that at least one pair of adjacent retardation layers (which can be a pair of in-plane retardation layers, a pair of thickness-direction retardation layers, or a combination of in-plane and thickness-direction retardation layers) are stacked without an adhesive layer A sandwiched between them. Specifically, for example, it is preferable that the retardation layers are in direct contact or that they are stacked with only one or two alignment films sandwiched between them. In optical stacks with multiple retardation layers as described in this invention, when all retardation layers are stacked with an adhesive layer sandwiched between them, the reflectivity of the optical stack tends to increase due to the presence of multiple interfaces between the retardation layers and the adhesive layer with large refractive index differences, which are prone to interfacial reflection. By stacking adjacent retardation layers without an adhesive layer A sandwiched between them, the interfaces between the retardation layers and the adhesive layer can be reduced, suppressing the increase in the reflectivity of the optical stack, which in turn suppresses the reduction in the image display sharpness, i.e., the brightness difference between white and black displays.

[0298] (Laminating layer A (330) within λ / 2 part 300)

[0299] As described above, in the λ / 2 section 300, at least one bonding layer A can be sandwiched between adjacent phase difference layers (which can be between in-plane phase difference layers, between phase difference layers in the thickness direction, or between an in-plane phase difference layer and a phase difference layer in the thickness direction).

[0300] As the bonding layer A (330), the bonding layer described in the section on bonding layer D (200) can be appropriately used, and the bonding method can also be set to the same. The thickness of the bonding layer A (330) can be 7 μm or less, preferably 5 μm or less, but it can also be 3 μm or less, or even less than 3 μm. By thinning the bonding layer A, the thickness of the λ / 2 portion can be adjusted to an appropriate range, suppressing the reduction in the fineness of the image display. The thickness of the bonding layer A can be 0.001 μm or more, preferably 0.05 μm or more.

[0301] (Indentation elastic modulus of bonding layer A)

[0302] The compressive elastic modulus of the bonding layer A is not particularly limited; however, it is preferably 3 MPa or more, more preferably 5 MPa or more, further preferably 8 MPa or more, and even more preferably 10 MPa or more. It can also be 50 MPa or more, 100 MPa or more, 500 MPa or more, 1000 MPa or more, 2000 MPa or more, or 2500 MPa or more. Typically, it is 6000 MPa or less.

[0303] The following description, as examples, illustrates two cases: one where the λ / 2 section 300 has a total of four phase retardation layers (two in-plane phase retardation layers and two thickness-direction phase retardation layers), and another where the λ / 2 section 300 has a total of three phase retardation layers (two in-plane phase retardation layers and one thickness-direction phase retardation layer). Even in these cases, the arrangement of the phase retardation layers is arbitrary; the following will refer to... Figure 1 and Figure 2 The following explanation will be based on the case where a pair of thickness-direction phase retardation layers 320 are disposed between two pairs of in-phase phase retardation layers 310. Furthermore, refer to... Figure 3 and Figure 4 The following example illustrates the case where a thickness-direction phase retardation layer 320 is disposed between two pairs of in-phase phase retardation layers 310.

[0304] Figure 1 and Figure 2 In the example, the λ / 2 part has four phase difference layers in sequence from the side of the first linear polarizer: an in-plane phase difference layer 310, a thickness direction phase difference layer 320, a thickness direction phase difference layer 320, and an in-plane phase difference layer 310. Figure 1 In the first linear polarizer, an adhesive layer A (hereinafter referred to as adhesive layer A1) 330 is sandwiched between the in-plane phase difference layer 310 and the thickness direction phase difference layer 320 on the side of the first linear polarizer, an adhesive layer A (hereinafter referred to as adhesive layer A2) 330 is sandwiched between the thickness direction phase difference layers 320, and an adhesive layer A (hereinafter referred to as adhesive layer A3) 330 is sandwiched between the in-plane phase difference layer 310 and the thickness direction phase difference layer 420 on the side opposite to the first linear polarizer.

[0305] It should be noted that, as mentioned above, when an adhesive layer A is sandwiched between the phase difference layers, the adhesive layer A and the phase difference layer can be in direct contact, or an alignment film can be sandwiched between them.

[0306] It should be noted that in the λ / 2 section, the bonding layers A1 to A3 are arbitrary; there can be any one, any two, or all three. When there is no bonding layer A between the phase difference layers, the phase difference layers can be directly stacked or stacked with an alignment film sandwiched between them.

[0307] An example of the λ / 2 part having any one bonding layer A is the case where there is no bonding layer A1 and bonding layer A3 but there is bonding layer A2. For example, as... Figure 2 As shown, in the λ / 2 section 300, there is no bonding layer A between the in-plane phase difference layer 310 and the thickness direction phase difference layer 320 on the side of the first linear polarizer, and there is no bonding layer A between the in-plane phase difference layer 310 and the thickness direction phase difference layer 320 on the side opposite to the first linear polarizer, but there is a bonding layer A between the thickness direction phase difference layers 320.

[0308] It should be noted that, as mentioned above, the bonding layer A2 and the phase difference layer can be in direct contact, or an alignment film can be sandwiched between them.

[0309] in addition, Figure 3 and Figure 4 In the example, the λ / 2 part has three phase difference layers in sequence from the linear polarizer side: an in-plane phase difference layer 310, a thickness direction phase difference layer 320, and an in-plane phase difference layer 310. Figure 3 In the process, an adhesive layer A (hereinafter referred to as adhesive layer A1) 330 is sandwiched between the in-plane phase difference layer 310 and the thickness direction phase difference layer 320 on the linear polarizer side. On the other hand, no adhesive layer A is sandwiched between the in-plane phase difference layer 310 and the thickness direction phase difference layer 320 on the side opposite to the linear polarizer. Figure 4 In the λ / 2 section 300, no bonding layer A is sandwiched between the in-plane phase retardation layer 310 and the thickness direction phase retardation layer 320 on the linear polarizer side. On the other hand, a bonding layer A is sandwiched between the in-plane phase retardation layer 310 and the thickness direction phase retardation layer 320 on the side opposite to the linear polarizer. It should be noted that, as described above, when a bonding layer A is sandwiched between the phase retardation layers, it can be in direct contact with the phase retardation layers, or an alignment film can be sandwiched between them. When there is no bonding layer A between the phase retardation layers, the phase retardation layers can be directly stacked, or they can be stacked with an alignment film sandwiched between them.

[0310] (Thickness of λ / 2 section)

[0311] In this embodiment, the thickness of the λ / 2 portion can be 4–80 μm, or 5–80 μm. The upper limit can also be 70 μm or less, 60 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less. Particularly preferred is a thickness of 15 μm or less. The thickness of the λ / 2 portion can also be 6 μm or more, or 10 μm or more. If the λ / 2 portion is too thick, the optical path length of the light transmitted through the optical laminate increases, resulting in increased light scattering, increased reflectivity of the optical laminate, and decreased image display resolution.

[0312] The thickness of the λ / 2 section is the sum of the thicknesses of each of the outermost pair of in-plane retardation layers 310 in the λ / 2 section and the distances between the two outermost in-plane retardation layers 310. In the case where an alignment film is present between the outermost pair of in-plane retardation layers, the thickness of the alignment film is also included.

[0313] The thickness of the λ / 2 section can be adjusted by utilizing the thickness of the in-plane phase difference layer 310, the thickness direction phase difference layer 320, and the bonding layer A, or it can be controlled by not setting the bonding layer A, but by stacking the phase difference layers directly or only with the orientation layer in between.

[0314] From the perspective of reducing the thickness of the λ / 2 portion, the bonding layer A is suitable as a cured layer of an active energy ray-cured adhesive or an active energy ray-cured bonding agent.

[0315] The ratio of the total thickness of all bonding layers A in the λ / 2 section to the thickness of the λ / 2 section is preferably 0.75 or less, particularly suitable to be 0.50 or less, and can be 0.40 or less or 0.30 or less.

[0316] (λ / 4 parts 400)

[0317] The λ / 4 section 400 has the function of imparting a phase difference of approximately λ / 4 to the incident light of wavelength λ.

[0318] The λ / 4 section 400 has an in-plane retardation layer 410. The λ / 4 section 400 may further have a thickness-direction retardation layer 420 (e.g., see reference). Figures 1-4 It can also have more than one thickness-direction phase retardation layer 420. When there is only one thickness-direction phase retardation layer 420, the single thickness-direction phase retardation layer 420 can be disposed relative to the in-plane phase retardation layer 410 on the side of the first linear polarizer (e.g., refer to...). Figure 2 and Figure 4 It can also be configured on the side opposite to the first linear polarizer (e.g., refer to...). Figure 1 and Figure 3 However, from the viewpoint of suppressing deformation under high temperature conditions, it is suitable to place the in-plane phase retardation layer 410 on the side opposite to the first linear polarizer. In addition, when there are two phase retardation layers 420 in the thickness direction, it is suitable to have one phase retardation layer 420 in the thickness direction, one in-plane phase retardation layer 410 and one phase retardation layer 420 in the thickness direction sequentially from the side closest to the linear polarizer.

[0319] The in-plane phase retardation layer 410 of the λ / 4 part can be the same as the in-plane phase retardation layer 310 described in the λ / 2 part. The in-plane phase retardation layer 410 of the λ / 4 part and the in-plane phase retardation layer 310 of the λ / 2 part can be the same or different from each other.

[0320] The thickness direction phase difference layer 420 of the λ / 4 part can be the thickness direction phase difference layer 320 described in the λ / 2 part. The thickness direction phase difference layer 420 of the λ / 4 part and the thickness direction phase difference layer 320 of the λ / 2 part can be the same or different from each other.

[0321] The phase difference value Rth(550) in the thickness direction of the phase retardation layer 420 at a wavelength of 550 nm can be -170 nm or more, -150 nm or more, more preferably -120 nm or more, more preferably -100 nm or more, and even more preferably -80 nm or more. It can also be -70 nm or more, or -65 nm or more. Furthermore, the phase difference value Rth(550) in the thickness direction of the phase retardation layer 420 at a wavelength of 550 nm can be 0 nm or less, -10 nm or less, more preferably -20 nm or less, and also suitable for -30 nm or less. If the phase difference value in the thickness direction is within this range, the image display detail in the tilt direction can be further improved.

[0322] When the phase retardation layer 420 in the thickness direction is a stretched film, its thickness is typically 300 μm or less, preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. When the phase retardation layer 420 in the thickness direction is a coating layer formed by polymerizing a polymeric liquid crystal, its thickness is typically 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0323] The in-plane phase difference value Re(550) at a wavelength of 550nm in the thickness direction phase difference layer 420 is typically in the range of 0 to 10nm, preferably in the range of 0 to 5nm.

[0324] (λ / 4 parts 400 bonding layer C (430))

[0325] Between the phase difference layers in λ / 4 part 400, for example, Figure 2 As shown, there may be no bonding layer C between the in-plane phase retardation layer 410 and the thickness direction phase retardation layer 420. For example, the in-plane phase retardation layer 410 and the thickness direction phase retardation layer 420 may be in direct contact, or only one or two alignment films may be sandwiched between these phase retardation layers.

[0326] Alternatively, it can be like Figure 1 As shown, an adhesive layer C (430) is sandwiched between the in-plane phase retardation layer 410 and the thickness-direction phase retardation layer 420. When the adhesive layer C is sandwiched, there may be an alignment film between the phase retardation layer and the adhesive layer C, or there may be no alignment film.

[0327] As the bonding layer C (430), the bonding layer described in the section on bonding layer D (200) can be used appropriately, and the bonding method can also be set to the same. The thickness of the bonding layer C (430) is not limited, and can be less than 7 μm, less than 5 μm, or less than 3 μm, more preferably less than 3 μm.

[0328] From the viewpoint of reducing the thickness of the λ / 2 portion, the bonding layer C is suitable as a cured layer of an active energy ray-cured adhesive or an active energy ray-cured bonding agent. From the viewpoint of suppressing the increase in reflectivity of the optical laminate, it is particularly suitable as an active energy ray-cured adhesive.

[0329] (Indentation elastic modulus of bonding layer C)

[0330] The compressive modulus of the bonding layer C is not particularly limited; however, from the viewpoint of suppressing wrinkles after bending, the compressive modulus of the bonding layer C is preferably 3 MPa or more, more preferably 10 MPa or more, and may also be 50 MPa or more, 100 MPa or more, 500 MPa or more, 1000 MPa or more, 2000 MPa or more, or 2500 MPa or more. Additionally, it is typically 6000 MPa or less.

[0331] In the λ / 4 section, from the viewpoint of suppressing the reduction in the fineness of the image display, it is preferable that at least one pair of adjacent phase difference layers (which may be between an in-plane phase difference layer and a phase difference layer in the thickness direction, or between phase difference layers in the thickness direction) are stacked without any bonding layer between them. For example, the phase difference layers are in direct contact with each other, or the phase difference layers are stacked with only one or two orientation films between them.

[0332] (The relationship between the slow axis of the λ / 2 section and the slow axis of the λ / 4 section and the transmission axis of the first linear polarizer)

[0333] Figure 5 This is a schematic diagram illustrating an example of the configuration relationship between the slow axis 300SA of the λ / 2 section 300 and the slow axis 400SA of the λ / 4 section 400 and the transmission axis 120TA of the first linear polarizer 120A. For example... Figure 5As shown, the λ / 2 section 300 and the λ / 4 section 400 are configured such that the angle θ1 between the slow axis 300SA of the λ / 2 section 300 and the slow axis 400SA of the λ / 4 section 400 is approximately 60°. Approximately 60° means a range of 60° ± 5°. The λ / 2 section 300 is preferably configured such that, relative to the first linear polarizer 120A, the angle θ2 between the slow axis 300SA of the λ / 2 section 300 and the transmission axis 120TA of the first linear polarizer 120A is approximately 15° or approximately 105°. Approximately 15° means a range of 15° ± 5°. Approximately 105° means a range of 105° ± 5°. In this case, the λ / 4 section 400 is preferably configured such that, relative to the first linear polarizer 120A, the angle θ3 formed by the slow axis 400SA of the λ / 4 section 400 and the transmission axis 120TA of the first linear polarizer 120A is approximately 75° or approximately 165°. Approximately 75° means a range of 75° ± 5°. Approximately 165° means a range of 165° ± 5°.

[0334] In this case, since the wavelength dispersion of the in-plane phase difference of the phase difference stack is close to linear, the phase difference stack can easily impart an ideal λ / 4 phase difference over a wide range of visible light. Therefore, a neutral hue is formed, which is excellent in suppressing the reduction in image display sharpness caused by the image display element.

[0335] Furthermore, if both the λ / 2 and λ / 4 portions further possess the aforementioned thickness-direction phase difference layer, the characteristics in the tilt direction are also improved.

[0336] The slow axis of each in-plane phasing layer 310 of the λ / 2 section 300 is configured to be approximately aligned with the slow axis 300SA of the λ / 2 section 300. Similarly, the slow axis of the in-plane phasing layer 410 of the λ / 4 section 400 is approximately aligned with the slow axis 400SA of the λ / 4 section 400. "Approximately aligned" means that the directions of the two slow axes can deviate by about ±5° (the same applies below).

[0337] (Lamination layer B)

[0338] A bonding layer B (500) can be provided between the phase difference layer of the λ / 2 section 300 and the phase difference layer of the λ / 4 section 400. For example, in Figure 1 and Figure 2 and Figure 3 In this configuration, the in-plane phase difference layer 310 of the λ / 2 portion 300 furthest from the first linear polarizer and the in-plane phase difference layer 410 of the λ / 4 portion 400 are bonded together by the bonding layer B (500). Additionally, in Figure 4In this method, no bonding layer is sandwiched between the in-plane phase difference layer 310 of the λ / 2 part 300 furthest from the linear polarizer and the thickness direction phase difference layer 420 of the λ / 4 part 400; instead, the alignment film is stacked directly or sandwiched between them.

[0339] As the bonding layer B (500), the bonding layer described in the section on bonding layer D (200) can be used, and the bonding method can also be set to the same. The thickness of the bonding layer B is not particularly limited, however, from the viewpoint of suppressing the increase of reflectivity of the optical laminate, it is preferably 7 μm or less, more preferably 5 μm or less, further preferably 3 μm or less, and particularly preferably less than 3 μm. An alignment film may be provided between the phase retardation layer and the bonding layer D. The λ / 2 portion and the λ / 4 portion may also be laminated without the bonding layer.

[0340] When bonding layer B bonds in-plane retardation layers together, especially from the viewpoint of reducing the refractive index difference between the in-plane retardation layers, which tend to increase with respect to the in-plane average refractive index, and suppressing interface reflection, it is preferable that the in-plane average refractive index of bonding layer B is 1.50 or higher. The in-plane average refractive index of bonding layer B can also be 1.52 or higher. Furthermore, the absolute value of the difference between the in-plane average refractive index of the in-plane retardation layer to which bonding layer B is bonded and the in-plane average refractive index of bonding layer B is preferably 0.10 or less, and more preferably 0.06 or less.

[0341] If the total thickness of the λ / 2 portion, the bonding layer B, and the λ / 4 portion—in other words, if the thickness from the surface of the λ / 2 portion on the linear polarizer side to the surface of the λ / 4 portion on the side opposite to the linear polarizer—is 100 μm or less, then it is suitable from the viewpoint of suppressing the reduction in image display sharpness. This total thickness can also be 50 μm or less, 30 μm or less, or 20 μm or less. It should be noted that the presence of the bonding layer B is arbitrary.

[0342] The average thickness of all the adhesive layers present in the λ / 2 portion, the adhesive layer B, and the λ / 4 portion—more specifically, in the portion from the surface of the linear polarizer side of the λ / 2 portion to the surface of the λ / 4 portion on the side opposite to the linear polarizer—is preferably 7 μm or less, more preferably 5 μm or less, and particularly suitable to be less than 5 μm. It should be noted that the presence of the adhesive layer B is arbitrary.

[0343] It should be noted that when the phase difference layers of the phase difference layer stack 600 are sequentially referred to as the first in-plane phase difference layer, the second in-plane phase difference layer, and the third in-plane phase difference layer from the first linear polarizer side, the bonding layer B is disposed between the second in-plane phase difference layer and the third in-plane phase difference layer.

[0344] (Indentation elastic modulus of bonding layer B)

[0345] The compressive elastic modulus of the bonding layer B is not particularly limited; however, it is preferably 3 MPa or more, more preferably 10 MPa or more, and can also be 50 MPa or more, 100 MPa or more, 500 MPa or more, 1000 MPa or more, 2000 MPa or more, or 2500 MPa or more. It is typically 6000 MPa or less. Furthermore, especially when the linear polarizer is a cured product of dichroic pigments and polymeric liquid crystal compounds that are relatively difficult to shrink even at high temperatures, if the compressive elastic modulus of the bonding layer B is sufficiently high and does not easily shrink, then deformation of the multiple phase décor layers sandwiched between the two difficult-to-shrink layers is suppressed, thus suppressing deformation such as color changes and curling at high temperatures.

[0346] From the viewpoint of suppressing the reduction in image display detail, the bonding layer B is suitable as a cured layer of an active energy radiation-cured adhesive or an active energy radiation-cured bonding agent. From the viewpoint of increasing the in-plane average refractive index of the bonding layer B, it is particularly suitable as an active energy radiation-cured bonding agent.

[0347] (Adhesive layer Z (700))

[0348] The optical laminate 10 may have an adhesive layer Z (700) on the side opposite to the visible side of the λ / 4 portion, that is, on the side of the phase difference layer laminate 600 opposite to the first linear polarizer. The adhesive layer Z may be the adhesive layer exemplified in the bonding layer D. The thickness of the adhesive layer Z may be set to 1 μm or more and 100 μm or less, and is preferably 5 μm or more and 50 μm or less.

[0349] The compressive modulus of the bonding layer Z is not particularly limited; however, the compressive modulus of the adhesive layer Z is preferably 500 MPa or less, more preferably 20 MPa or less, even more preferably 10 MPa or less, and even more preferably 5 MPa or less. It may also be 3 MPa or less, or less than 3 MPa. In addition, it is usually 0.1 MPa or more. If the compressive modulus of the adhesive layer Z is within the above-mentioned range, then when the optical laminate is bonded to the image display device with the adhesive layer Z sandwiched between it, the warping of the image display device can be suppressed.

[0350] (Relationship of the compressive elastic modulus of the bonding layer in the phase difference layer laminate 600)

[0351] In this embodiment, the phase retardation layer stack 600 has three or more phase retardation layers including three or more in-plane phase retardation layers (e.g., Figure 1 , 2The middle layer consists of an in-plane phase retardation layer 310, a thickness-direction phase retardation layer 320, an in-plane phase retardation layer 410, and a thickness-direction phase retardation layer 420), and an bonding layer disposed between at least one pair of phase retardation layers (e.g., Figure 1 The middle layer consists of bonding layers A1 to A3 (330), bonding layer B (500), and bonding layer C (430). Figure 2 The middle layer consists of bonding layer A2 (330) and bonding layer B (500)), at least one of which has an indentation modulus of elasticity of 3 MPa or more. The indentation modulus of elasticity may be 6000 MPa or less.

[0352] The average compressive elastic modulus of all bonding layers between the phase difference layers in the phase difference layer stack 600 is preferably 3 MPa or more. Preferably, this average value is 10 MPa or more, more preferably 500 MPa or more, even more preferably 1000 MPa or more, and particularly preferably 1500 MPa or more. However, this average value is typically 6000 MPa or less.

[0353] The phase retardation layer stack 600, starting from the side of the first linear polarizer 120A, sequentially includes an in-plane phase retardation layer 310 (first in-plane phase retardation layer), at least one bonding layer A (e.g., ...). Figure 1 The middle layer is the bonding layer A1 to A3. Figure 2 The middle layer consists of an adhesive layer A2), an in-plane phase difference layer 310 (a second in-plane phase difference layer), and at least one adhesive layer B (e.g., Figure 1 , 2 In the case where the middle layer is the bonding layer B (500) and the in-plane phase difference layer 410 (the third in-plane phase difference layer),

[0354] When the indentation modulus of the layer with the smallest indentation modulus is set to EAmin in the bonding layer A between the in-plane phase difference layer 310 (first in-plane phase difference layer) disposed on the first linear polarizer side of the λ / 2 part 300 and the in-plane phase difference layer 310 (second in-plane phase difference layer) disposed on the opposite side of the λ / 2 part 300, and the indentation modulus of the layer with the smallest indentation modulus is set to EBmin in the bonding layer B between the in-plane phase difference layer 310 (second in-plane phase difference layer) disposed on the opposite side of the first linear polarizer side of the λ / 2 part 300 and the in-plane phase difference layer 410 (third in-plane phase difference layer) disposed on the first linear polarizer side of the λ / 4 part 400, it is suitable to satisfy EAmin≤EBmin.

[0355] When the adhesive layer D (200) is further provided between the first linear polarizer 120A and the phase difference layer stack 600, and the adhesive layer Z (700) is provided on the side opposite to the first linear polarizer 120A relative to the phase difference layer stack 600, when the indentation elastic modulus of the adhesive layer D (200) is set to ED and the indentation elastic modulus of the adhesive Z (700) is set to EZ, it is suitable to satisfy EZ<EAmin≤EBmin and EZ<ED.

[0356] The value of EBmin relative to the indented elastic modulus α of the layer with the smallest indented elastic modulus among the in-plane phase difference layers is preferably 0.002 or higher. EBmin / α can be 0.003 or higher, 0.005 or higher, 0.1 or higher, or 1.0 or higher.

[0357] (Optical laminate 10 of the second embodiment (part of the optical system in the image display device))

[0358] The following reference Figures 6-9 The optical laminate 10 of the second embodiment will be described. In this section, points that differ from the first embodiment will be explained, and repetitive descriptions will be omitted. For example... Figures 6-9 As shown, the optical laminate 10 of the second embodiment sequentially includes a first linear polarizer 120A and a phase difference layer laminate 600. In this embodiment, the first linear polarizer 120A is a reflective polarizer.

[0359] (Reflective polarizer)

[0360] A reflective polarizer is a polarization conversion element that separates natural light into transmitted polarized light and reflected or scattered polarized light. Specifically, a reflective polarizer can be an anisotropic multi-film that transmits linearly polarized light in one direction of vibration and reflects linearly polarized light in the opposite direction of vibration. Commercially available products of this anisotropic multi-film may use trade names such as "DBEF" or "APF" (manufactured by 3M Corporation, Sumitomo 3M Co., Ltd.). The principle of the reflective polarizer is not limited; it can be a polarizer obtained by combining a cholesteric liquid crystal and a λ / 4 plate.

[0361] The thickness of a reflective polarizer can be around 10 to 100 μm. From the perspective of thin-film optical laminates, composite polarizers, and liquid crystal display devices, the thickness of a reflective polarizer is preferably 10 to 50 μm.

[0362] The polarization properties of the reflective polarizer, such as the single-unit transmittance, degree of polarization, and visibility-corrected polarization degree Py, can be the same as those of the first linear polarizer in the first embodiment.

[0363] In particular, in this embodiment, the in-plane standard deviation σ of the visibility-corrected polarization degree Py of the first linear polarizer 120A is also 0.001% or more. If this standard deviation σ is less than 0.001%, the linear polarizer has high orientation, and therefore, even when used as various optical components by stacking with arbitrary phase difference layers as shown in the reference example described later, the reflection accuracy is not easily reduced. The standard deviation σ can be 0.002% or more, 0.003% or more, 0.004% or more, or 0.005% or more. In addition, the standard deviation σ is usually 0.100% or less. If the standard deviation σ is too large, it will cause disorder in the image display when used in an image display device. The unit of the visibility-corrected polarization degree Py used for calculating the standard deviation σ is %.

[0364] Figures 6-9 The phase difference layer stack 600 is the same as that described in the first embodiment. Specifically, Figure 6 Phase difference layer stack 600 and Figure 1 The phase difference layers of the stacked structure are the same at 600°. Figure 7 Phase difference layer stack 600 and Figure 2 The phase difference layer stack is the same as that of the 600-layer stack. Figure 8 Phase difference layer stack 600 and Figure 3 The phase difference layers of the stacked structure are the same at 600°. Figure 9 Phase difference layer stack 600 and Figure 4 The phase difference layer stack is the same as that of the 600-layer stack.

[0365] Between the first linear polarizer 120A and the phase difference layer stack 600, there may be any optical component 200Q. Examples of any optical component 200Q are adhesives, bonding agents, or other bonding layers, optical lenses, etc.

[0366] (Second linear polarizer 120B)

[0367] The optical laminate 10 of this embodiment may further include a second linear polarizer 120B. For example, Figures 6-9 In the example shown, a second linear polarizer 120B is provided on the side opposite to the phase difference layer stack 600, respectively, relative to the first linear polarizer 120A.

[0368] The second linear polarizer 120B is either an absorptive polarizer or a reflective polarizer. The second linear polarizer 120B can be appropriately selected from absorptive and reflective polarizers; in this embodiment, the second linear polarizer 120B is suitable as an absorptive polarizer. It should be noted that, regarding absorptive polarizers, as described in the first embodiment...

[0369] The transmission axis of the first linear polarizer 120A and the transmission axis of the second linear polarizer 120B are approximately aligned. "Approximately aligned" means within a range of ±5°.

[0370] It should be noted that as long as the standard deviation σ of at least one of the visibility correction polarization degree Py of the first linear polarizer 120A or the second linear polarizer 120B meets the above-mentioned lower limit condition, it is acceptable whether either one meets the condition.

[0371] Between the first linear polarizer 120A and the second linear polarizer 120B, any optical component 190Q may exist. Examples include adhesives, bonding layers, optical lenses, etc.

[0372] (Effects)

[0373] According to the optical laminate of this embodiment, high reflection accuracy can be achieved even when the orientation of the linear polarizer is non-uniform, that is, the in-plane reflectivity can be made uniform. Although the reason is not clear, the following effect can be considered.

[0374] The optical laminate of this embodiment has a first linear polarizer and three or more phase retardation layers, at least three of which are in-plane phase retardation layers. The first linear polarizer is an absorptive polarizer or a reflective polarizer, and the in-plane standard deviation σ of the visibility correction polarization degree Py of the first linear polarizer is 0.003% or more. A standard deviation σ greater than a specific lower limit indicates a large fluctuation in the orientation of the first linear polarizer.

[0375] The phase difference layer stack of this embodiment exhibits a near-linear wavelength dispersion of in-plane phase difference, making it easy to impart an ideal λ / 4 phase difference over a wide range of visible light. Consequently, since light transmitted through the phase difference layer stack can be converted into elliptically polarized light with a high ellipticity, high reflection accuracy can be achieved in the optical stack even when the orientation of the linear polarizer is non-uniform.

[0376] It should be noted that the present invention is not limited to the above-described manner and can achieve various modified forms. For example, the phase difference layer stack is not limited to a stack with λ / 2 and λ / 4 portions, as long as it has three or more phase difference layers, and at least three of the three or more phase difference layers are in-plane phase difference layers.

[0377] In this case, even if the in-plane standard deviation of the visibility correction polarization degree Py of the first linear polarizer is greater than 0.001%, the fluctuation of reflectivity can still be reduced.

[0378] <Image display device>

[0379] The optical laminate of this embodiment can be suitably used as a component of an image display device. The image display device is not particularly limited; examples include organic electroluminescent (organic EL) display devices, inorganic electroluminescent (inorganic EL) display devices, liquid crystal display devices, and electric field emission display devices.

[0380] Examples of suitable image display devices include head-mounted displays for VR and AR applications. Head-mounted displays can be frame-shaped, helmet-shaped, or goggle-shaped. In these head-mounted displays, it is known that a composite polarizing plate, consisting of stacked reflective and absorptive polarizing plates, is combined with optical lenses to widen the viewing angle and achieve a high degree of immersion and presence. Therefore, it is particularly suitable for VR and AR head-mounted displays when the first linear polarizer is a reflective polarizer and the second linear polarizer is an absorptive polarizer.

[0381] When an optical laminate containing a first linear polarizer that is a reflective polarizer and a second linear polarizer that is an absorptive polarizer is applied to a head-mounted display for VR or AR, the display system may, for example, sequentially include an image display element, an arbitrary circular polarizer, a semi-transparent mirror, an optical lens, and an optical laminate (a phase difference layer laminate, a reflective polarizer, and an absorptive polarizer). The image display element, for example, is a liquid crystal display (LCD) or an organic EL display, having a display surface for displaying images, with a circular polarizer laminated on the display surface side.

[0382] Light emitted from the image display element is converted into circularly polarized light by a circular polarizer. After passing through a semi-transparent mirror, it is converted into linearly polarized light by a phase difference stack and reaches a reflective polarizer. The reflective polarizer causes this light to be reflected towards the semi-transparent mirror, which in turn causes the reflected light from the reflective polarizer to be reflected again towards the reflective polarizer. Since this reflected light is linearly polarized and parallel to the transmission axes of both the reflective and absorptive polarizers, it passes through both the reflective and absorptive polarizers and enters the user's eye.

[0383] Example

[0384] The present invention will now be described in more detail based on embodiments and comparative examples; however, the present invention is not limited to the following embodiments. Unless otherwise specified, “%” and “parts” in the examples refer to mass % and mass parts, respectively.

[0385] (Fabrication of Absorption Polarizing Plate 1)

[0386] Similar to paragraphs 0141 to 0150 of Japanese Patent Application Publication No. 2024-018946, an absorption-type polarizing plate 1 comprising a TAC film / liquid crystal polarizer (optical alignment film / cured layer) / OC layer is obtained. In this case, the TAC film constitutes the first protective layer, and the OC layer constitutes the second protective layer. It should be noted that the compressive elastic modulus of the cured layer in the liquid crystal polarizer is 680 MPa.

[0387] (Preparation of reflective polarizer 1)

[0388] As a reflective polarizer 1, it is prepared to be manufactured by 3M. TM APF (Advanced Photopolymer Film) for Brightening.

[0389] (Adhesive Composition A)

[0390] After mixing the following ingredients, degassing is performed to prepare adhesive composition A.

[0391] • Neopentyl glycol diglycidyl ether (trade name: EX-211L, manufactured by Nagase ChemteX Co., Ltd.): 30 parts by weight

[0392] ·3-Ethyl-3{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toa Synthetic Co., Ltd.): 13 parts by weight

[0393] • Bisphenol A type epoxy resin (trade name: EP-4100E, ADEKA Co., Ltd., viscosity 13 Pa·s (temperature 25°C)): 45 parts by weight

[0394] • Aromatic oxetane compounds (trade name: TCM-104, manufactured by TRONLY): 12 parts by weight

[0395] • Cationic polymerization initiator (trade name: CPI-100 50% solution, manufactured by SanApro Co., Ltd.): 5.5 parts by weight (2.75 parts by weight of solid content)

[0396] ·1,4-Diethoxynaphthalene: 1.2 parts by weight

[0397] ·9,10-Dibutoxyanthracene: 1.9 parts by weight

[0398] • Organosilicon-based leveling agent (trade name: KP-341, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.25 parts by weight

[0399] The cured adhesive composition A has an in-plane average refractive index of 1.54 and an indentation modulus of 3000 MPa.

[0400] (Fabrication of adhesive sheet (1) containing adhesive layer (1))

[0401] (2-1) Preparation of acrylic resin solution (1)

[0402] A mixture of 100 parts ethyl acetate, 99.0 parts butyl acrylate, 0.5 parts 2-hydroxyethyl acrylate, and 0.5 parts acrylic acid was added to a reaction vessel equipped with a condenser, a nitrogen inlet pipe, a thermometer, and a stirrer. The internal temperature was raised to 55°C while purging the air in the apparatus with nitrogen to eliminate oxygen. Then, the entire amount of a solution obtained by dissolving 0.12 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was added. After adding the polymerization initiator, the temperature was maintained for 1 hour. Then, while maintaining the internal temperature at 54–56°C, ethyl acetate was continuously added to the reaction vessel at a rate of 17.3 parts / hr. The addition of ethyl acetate was stopped when the concentration of (meth)acrylic resin reached 35% by mass. The temperature was then maintained for another 6 hours from the start of ethyl acetate addition. Finally, ethyl acetate was added to adjust the concentration of (meth)acrylic resin to 20% by mass, preparing an acrylic resin solution (1). The obtained acrylic resin had a weight-average molecular weight (Mw) of 1.7 million and a molecular weight distribution (Mw / Mn) of 3.9. It should be noted that Mw and Mn were determined as follows: two TSKgel GMH resins manufactured by Tosoh Corporation were connected in series in the GPC apparatus. HR Using "-H(S)" as the chromatographic column and tetrahydrofuran as the eluent, the sample concentration was 2 mg / mL, the sample introduction volume was 100 μL, the temperature was 40℃, and the flow rate was 1 mL / min. The determination was performed by conversion to standard polystyrene.

[0403] (2-2) Preparation of adhesive composition (1)

[0404] For 80 parts of the solid component of the acrylic resin solution (1) obtained in (2-1), 20 parts (solid component) of difunctional acrylate (obtained from Shin-Nakamura Chemical Industry Co., Ltd.; product number "A-DOG"), 2.5 parts of crosslinking agent (manufactured by Tosoh Co., Ltd.: trade name "CORONATE L" (ethyl acetate solution of trimethylolpropane adduct of toluene diisocyanate (solid component concentration 75% by mass)), 1.5 parts of photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd.: trade name "Irgacure 500"), and 0.3 parts of silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.: trade name "KBM-403") were added, and ethyl acetate was further added to make the solid component concentration 13% to obtain the adhesive composition (1).

[0405] A-DOG is a diacrylate of an acetal compound of hydroxypentanal and trimethylolpropane, having the following structure.

[0406] [Chemistry 4]

[0407]

[0408] (2-3) Preparation of adhesive layer (1)

[0409] Using an applicator, the adhesive composition prepared in (2-2) above is applied to the release-treated surface of a spacer film ("PLZ-383030" obtained from LINTEC Co., Ltd.) made of polyethylene terephthalate film that has undergone release treatment, such that the dried thickness is 15 μm. The adhesive layer (adhesive sheet) is then dried at 100°C for 1 minute. Then, the surface of the adhesive layer opposite to the spacer film is bonded to the release-treated surface of a spacer film ("PLR-381031" obtained from LINTEC Co., Ltd.) made of polyethylene terephthalate film that has undergone release treatment. Next, the spacer / adhesive layer (1) / spacer adhesive sheet (1) is produced by irradiating with ultraviolet light under the following conditions. The spacer film was peeled off from the prepared adhesive sheet (1), and the in-plane average refractive index (wavelength 589 nm) of the adhesive layer (1) was measured at 25°C using a multi-wavelength Abbe refractometer [ATAGO Corporation "DR-M2"]. The in-plane average refractive index of the adhesive layer (1) was 1.47, and the compressive modulus was 11.3 MPa.

[0410] <UV Irradiation Conditions>

[0411] • Uses Fusion UV lamp system (manufactured by Fusion UV Systems) H-lamp tubes

[0412] • Cumulative light intensity 250mJ / cm 2

[0413] (Preparation of adhesive sheet (2) containing adhesive layer (2))

[0414] Except for changing the thickness of the adhesive layer from 15 μm to 5 μm, an adhesive sheet (2) containing an adhesive layer (2) was fabricated in the same manner as the adhesive sheet (1). The in-plane average refractive index was measured in the same manner as the adhesive sheet (1), and the result was that the in-plane average refractive index of the adhesive layer (2) was 1.47. The compressive modulus of the adhesive layer (2) was 11.3 MPa.

[0415] [Preparation of a composition for forming an optically aligned film for in-plane phase difference]

[0416] A photo-alignment material with the following structure (weight average molecular weight: 50,000, m:n = 50:50) was manufactured according to the method described in Japanese Patent Application Publication No. 2021-196514. Two parts of the photo-alignment material and 98 parts of cyclopentanone (solvent) were mixed as components, and the resulting mixture was stirred at 80°C for 1 hour to prepare a composition for photo-alignment film formation.

[0417] Photooriented materials:

[0418] [Chemistry 5]

[0419]

[0420] [Preparation of polymeric liquid crystal compounds for in-plane phase retardation]

[0421] Polymerizable liquid crystal compounds (A1) and (A2) having the structures shown below were prepared respectively. Polymerizable liquid crystal compound (A1) was prepared in the same manner as described in Japanese Patent Application Publication No. 2019-003177. Polymerizable liquid crystal compound (A2) was prepared in the same manner as described in Japanese Patent Application Publication No. 2009-173893.

[0422] Polymerizable liquid crystal compound (A1):

[0423] [Chemistry 6]

[0424]

[0425] Polymerizable liquid crystal compound (A2):

[0426] [Chemistry 7]

[0427]

[0428] A solution was prepared by dissolving 1 mg of a polymerizable liquid crystal compound (Al) in 10 mL of chloroform. This solution was then added to a measuring dish with a 1 cm optical path length. The sample was placed in a UV-Vis spectrophotometer (Shimadzu Corporation, "UV-2450") to measure the absorption spectrum. The wavelength at which maximum absorbance was achieved was read from the obtained absorption spectrum. The result showed that the maximum absorption wavelength λmax in the wavelength range of 300–400 nm was 356 nm.

[0429] [Preparation of composition (1) for forming phase difference layer]

[0430] Polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) were mixed at a mass ratio of 90:10 to obtain a mixture. 0.1 parts of leveling agent "BYK-361N" (manufactured by BM Chemie) and 3 parts of photopolymerization initiator "Irgacure OXE-03" (manufactured by BASF JAPAN Co., Ltd.) were added relative to 100 parts of the obtained mixture. N-methyl-2-pyrrolidone (NMP) was further added to achieve a solids concentration of 13%. The mixture was stirred at 80°C for 1 hour to prepare a phase retardation layer forming composition (1).

[0431] [Table 1]

[0432]

[0433] [Preparation of an oriented polymer composition for forming a phase détente layer in the thickness direction]

[0434] 2-Butoxyethanol was added to SUNEVER SE-610 (manufactured by Nissan Chemical Industries, Ltd.), a commercially available orientation polymer, to obtain an orientation polymer composition with a solid content of 1%.

[0435] [Preparation of composition (2) for forming a phase retardation layer in the thickness direction]

[0436] The polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF JAPAN), the leveling agent "BYK-361N" (manufactured by BYK-Chemie), and "Omnirad907" (manufactured by IGM Resin BV) as a photopolymerization initiator were added. Propylene glycol 1-monomethyl ether 2-acetate (PGME) was further added, and the mixture was stirred at 80°C for 1 hour to prepare a phase retardation layer forming composition (2).

[0437] [Table 2]

[0438]

[0439] Polymerizable liquid crystal compound LC242:

[0440] [Chemistry 8]

[0441]

[0442] (Fabrication of in-plane phase retardation film)

[0443] The above-mentioned composition for forming a photo-aligned film was applied to a biaxially stretched polyethylene terephthalate (PET) film (manufactured by Diafoil Mitsubishi Resin Co., Ltd.) as substrate (1) using a bar coater. The resulting coated film was dried at 120°C for 2 minutes and then cooled to room temperature to form a dried film. Subsequently, the film was irradiated with 100 mJ of polarized ultraviolet light (313 nm reference) using a UV irradiation device (SPOT CURE SP-9; manufactured by USHIO Electric Co., Ltd.) to obtain a photo-aligned film. The film thickness of the photo-aligned film, measured using an ellipsometer M-220 manufactured by Nippon Spectrophotometer Co., Ltd., was 100 nm.

[0444] The aforementioned phase retardation layer forming composition (1) was coated onto the obtained photo-aligned film using a bar coater to form a coated film. This coated film was then heated and dried at 120°C for 2 minutes, followed by cooling to room temperature to obtain a dried film. The dried film was then irradiated with a high-pressure mercury lamp (USHIO Electric Co., Ltd., "Unicure VB-15201BY-A") under a nitrogen atmosphere at an exposure dose of 500 mJ / cm². 2 Ultraviolet light (365 nm reference) is used to form an in-plane retardation layer, which is formed by curing a polymeric liquid crystal compound in a horizontally oriented state relative to the substrate plane. This results in an in-plane retardation film formed from the substrate (1) / photoalignment film / in-plane retardation layer A (horizontally oriented liquid crystal curing film). The thickness of the in-plane retardation layer, measured using a LEXTOLS4100 laser microscope manufactured by Olympus Corporation, is 2.0 μm. The indentation modulus of the in-plane retardation layer, measured using the method described later, is 2100 MPa.

[0445] The surface of the in-plane retardation film on the retardation layer side was corona treated, and then bonded to glass using a 25μm pressure-sensitive adhesive manufactured by LINTEC. The PET film was then peeled off. The in-plane phase difference value was measured using a KOBRA-WR manufactured by Oji Measurement & Control Co., Ltd. It should be noted that the in-plane phase difference values ​​for light with wavelengths of 450nm, 550nm, and 650nm were calculated using Cauchy's dispersion formula derived from the measurement results of the in-plane phase difference values ​​for light with wavelengths of 448.2nm, 498.6nm, 548.4nm, 587.3nm, 628.7nm, and 748.6nm.

[0446] As a result, the in-plane phase differences are Re(450) = 122nm, Re(550) = 140nm, and Re(650) = 144nm. The relationship between the in-plane phase differences at each wavelength is shown below.

[0447] Re(450) / Re(550)=0.87

[0448] Re(650) / Re(550)=1.03

[0449] (In the formula, Re(450) represents the in-plane phase difference for light with a wavelength of 450nm, Re(550) represents the in-plane phase difference for light with a wavelength of 550nm, and Re(650) represents the in-plane phase difference for light with a wavelength of 650nm.)

[0450] The in-plane average refractive index of the in-plane phase retardation layer is 1.59.

[0451] (Fabrication of phase retardation film in the thickness direction)

[0452] On a surface of cyclic olefin polymer (COP) (manufactured by ZEON Corporation, Japan, ZF14) that had undergone corona treatment using a corona treatment apparatus (AGF-B10; manufactured by Kasuga Electric Co., Ltd.), an orientation polymer composition was coated using a bar coater and dried at 90°C for 1 minute. The thickness of the resulting orientation film (1) was measured using a laser microscope and found to be 30 nm. Next, a phase retardation layer forming composition (2) was coated onto the orientation film (1) using a bar coater, and after drying at 90°C for 1 minute, the dried film was irradiated with a high-pressure mercury lamp (manufactured by USHIO Electric Co., Ltd., "Unicure VB-15201BY-A") under a nitrogen atmosphere with an exposure dose of 1000 mJ / cm. 2 Ultraviolet light (based on 365nm) was used to obtain a thickness direction retardation film composed of a substrate (2), an alignment film (1), and a thickness direction retardation layer C. The thickness of the thickness direction retardation layer was measured using a laser microscope, and the result was a thickness of 450nm. The in-plane average refractive index of the thickness direction retardation layer was 1.50. The in-plane phase difference value was measured using a KOBRA-WR manufactured by Oji Measurement Equipment Co., Ltd. The result was Re(550) = 1nm and Rth(550) = -70nm. Thus, it has optical properties expressed by the following formula (3). It should be noted that the phase difference value at the wavelength of COP 550nm is approximately 0, so it does not affect the optical properties.

[0453] nx≈ny<nz (3)

[0454] The indentation elastic modulus of the phase difference layer in the thickness direction is 2900 MPa.

[0455] (Fabrication of λ / 2 liquid crystal phase retardation layer H)

[0456] Similar to paragraphs 0162 to 0167 of Japanese Patent Application Publication No. 2024-018946, a λ / 2 liquid crystal phase retardation layer with a substrate is obtained, which is composed of a substrate / λ / 2 liquid crystal phase retardation layer H (alignment film (2) / cured layer).

[0457] (Fabrication of λ / 4 liquid crystal phase retardation layer Q)

[0458] Similar to paragraphs 0168 to 0170 of Japanese Patent Application Publication No. 2024-018946, a λ / 4 liquid crystal phase reversal layer with a substrate is obtained, which is composed of a substrate layer / λ / 4 liquid crystal phase reversal layer Q (alignment film (3) / cured layer (horizontal alignment liquid crystal cured film)).

[0459] (Example 1)

[0460] On the surface of the thickness direction phase retardation layer side of the thickness direction phase retardation film C obtained above, a composition for forming a photo-alignment film is coated using a bar coater. The resulting coated film is dried at 120°C for 2 minutes and then cooled to room temperature to form a dried film. Subsequently, the film is irradiated with 100 mJ of polarized ultraviolet light (313 nm reference) using a UV irradiation device (SPOT CURE SP-9; manufactured by USHIO Electric Co., Ltd.) to obtain a photo-alignment film (2). The film thickness of the photo-alignment film (2) is measured to be 100 nm using an ellipsometer M-220 manufactured by Nippon Spectrophotometer Co., Ltd.

[0461] On the obtained photoalignment film (2), the above-mentioned liquid crystal phase retardation layer forming composition (1) for in-plane phase retardation layer A is coated using a bar coater to form a coated film. The coated film is heated and dried at 120°C for 2 minutes and then cooled to room temperature to obtain a dried film. Then, the dried film is irradiated with an exposure dose of 500 mJ / cm under a nitrogen atmosphere using a high-pressure mercury lamp (USHIO Electric Co., Ltd. "Unicure VB-15201BY-A"). 2 Ultraviolet light (365nm reference) was used to form an in-plane retardation layer A, which was formed by curing a polymeric liquid crystal compound in a horizontally oriented state relative to the substrate plane. This resulted in a retardation film (3) composed of a substrate (2), an alignment film (1), a thickness-direction retardation layer C, a photoalignment film (2), and an in-plane retardation layer A. The thickness of the in-plane retardation layer A was measured to be 2.0 μm using a LEXTOLS4100 laser microscope manufactured by Olympus Corporation.

[0462] Peel the spacer from one side of the adhesive sheet (1) and laminate it onto the side of the second protective layer of the fabricated absorptive polarizing plate 1. Peel the remaining spacer from the opposite side of the adhesive sheet (1) and attach it to the side of the in-plane phase retardation layer A of the phase retardation film (3).

[0463] The substrate (2) on the phase difference layer side in the thickness direction is peeled off from the obtained laminate (the orientation film (1) is still retained), and the peeled spacer side of another adhesive sheet (2) is attached to it, which is set as laminate A-1.

[0464] Next, corona treatment was applied to the surface of the in-plane retardation layer A side of the other retardation film (3). Adhesive composition A was applied to form a layer using a coating machine (a bar coater manufactured by Daiichi Rikka Co., Ltd.). Then, corona treatment was applied to the surface of the in-plane retardation layer A side of the other retardation film (3), and the corona-treated surface was bonded to the layer of adhesive composition A using an adhesive bonding device ("LPA3301" manufactured by FUJIPLA Co., Ltd.). A cumulative light intensity of 1600 mJ / cm² was applied from one substrate (2) side using an ultraviolet irradiation device with a conveyor belt (using "V-lamp" manufactured by Fusion UV Systems Co., Ltd.) in the wavelength region of 395–445 nm (UVV region). 2 Visible light is used to cure the adhesive, thereby obtaining the laminate B-1. At this time, it is carried out in such a way that the difference in axial angle between the phase difference films (3) (specifically between the in-plane phase difference layers) is 60°.

[0465] The substrate (2) of one side of the laminate (the alignment film (1) is peeled off from laminate B-1) and the surface from which the spacer was peeled off from laminate A-1 is bonded together. Thereafter, the substrate (2) is peeled off from the resulting laminate, thereby forming an optical laminate (1).

[0466] The angle between the transmission axis of the polarizer of the resulting laminate and the slow axis of the λ / 2 part is 15°, the angle between the transmission axis of the polarizer and the slow axis of the λ / 4 part is 75°, and the angle between the λ / 2 part and the λ / 4 part is 60°.

[0467] It should be noted that the thickness of the adhesive layer obtained by curing the above adhesive composition A was measured, and the result was that the thickness was 1.5 μm.

[0468] (Example 2)

[0469] Except for replacing the absorptive polarizer 1 with the reflective polarizer 1, an optical laminate (2) is obtained in the same manner as in Example 1. It should be noted that the laminates are aligned in such a way that the reflection axis of the reflective polarizer coincides with the absorption axis of the absorptive polarizer.

[0470] (Example 3)

[0471] Peel the spacer from one side of the adhesive sheet (2) and laminate it onto the side of the optical laminate (2) facing the reflective polarizer 1. Peel the remaining spacer from the opposite side of the adhesive sheet (2) and laminate it onto the side of the second protective layer of the absorptive polarizer 1, thus forming the optical laminate (3). It should be noted that the laminates are aligned in such a way that the reflection axis of the reflective polarizer coincides with the absorption axis of the absorptive polarizer.

[0472] (Comparative Example 1)

[0473] (Fabrication of a phase difference body with a substrate layer)

[0474] Corona treatment was performed on the λ / 2 liquid crystal phase reversal layer H with substrate and the λ / 4 liquid crystal phase reversal layer Q with substrate, respectively. An adhesive layer (2) was sandwiched between the corona-treated surfaces to obtain a phase reversal body with substrate, consisting of substrate / λ / 2 liquid crystal phase reversal layer H (alignment film (2) / cured layer) / adhesive layer (2) / λ / 4 liquid crystal phase reversal layer Q (cured layer / alignment film (3)) / substrate. The angle between the slow axis of λ / 2 liquid crystal phase reversal layer H and the slow axis of λ / 4 liquid crystal phase reversal layer Q is 60°.

[0475] (Fabrication of optical laminate (4))

[0476] The second protective layer side of the absorptive polarizer 1 obtained above is subjected to corona treatment. Then, the substrate of the λ / 2 liquid crystal phase reversal layer H side of the phase reversal body with substrate obtained above is peeled off, and the peeled surface is subjected to corona treatment. The alignment film (2) is also peeled off at the same time as the substrate is peeled off. An adhesive layer (1) is sandwiched between the corona-treated surfaces. This bonding is performed so that the angle between the transmission axis of the absorptive polarizer and the slow axis of the λ / 2 liquid crystal phase reversal layer H is 15°. Afterward, the substrate of the λ / 4 liquid crystal phase reversal layer Q with substrate is peeled off, and it is set as an optical laminate (4).

[0477] (Comparative Example 2)

[0478] (Fabrication of Absorption-type Polarizing Plate 2)

[0479] A 20 μm thick polyvinyl alcohol (PVA) film (average degree of polymerization approximately 2400, degree of saponification ≥ 99.9 mol%) was uniaxially stretched to approximately 4 times its original thickness using a dry stretching method. While maintaining constant tension, it was immersed in pure water at 40°C for 40 seconds, followed by dyeing treatment by immersion in an aqueous solution of iodine / potassium iodide / water at 28°C for 30 seconds. Subsequently, it was immersed in an aqueous solution of potassium iodide / boric acid / water at 11.0 / 6.2 / 100 at 70°C for 120 seconds. After further washing with pure water at 8°C for 15 seconds, it was dried at 60°C for 50 seconds under a tension of 300 N, and then dried at 75°C for 20 seconds, yielding an 8 μm thick polarizer with iodine adsorbed and oriented on the PVA film. The compressive modulus of this polarizer is 9800 MPa.

[0480] A water-based adhesive formed from a polyvinyl alcohol-based resin aqueous solution is coated on both sides of the obtained polarizer, and a cyclic olefin resin film (manufactured by ZEON Corporation, Japan, ZEONOR ZF14) and a triacetyl cellulose (TAC) film (manufactured by Fujitac TJ25) are respectively bonded to obtain an absorptive polarizer 2.

[0481] Except for changing the absorptive polarizer 1 to the absorptive polarizer 2, an optical laminate (5) was obtained in the same manner as in Comparative Example 1. In this case, the TAC film side of the absorptive polarizer 2 was attached to the λ / 2 liquid crystal phase difference layer H.

[0482] (Example 4)

[0483] (Fabrication of in-plane phase retardation film A1 with substrate)

[0484] While conveying a 500mm wide × 100m roll of 100μm thick biaxially stretched polyethylene terephthalate (PET) film (manufactured by Diafoil Mitsubishi Resin Co., Ltd.) at a speed of 4m / min, a plasma treatment device was used to treat the film once with an output power of 0.4kW. After coating the plasma-treated surface with the above-mentioned photo-alignment film forming composition using a die-coating machine, the surface was dried at 120°C for 2 minutes and then irradiated with a polarized UV irradiation device at a cumulative light intensity of 100mJ / cm at a 15° angle relative to the width direction. 2 (Cumulative light intensity at a wavelength of 313 nm in air) was subjected to polarized UV exposure. The thickness of the photo-alignment film was measured to be 100 nm using an M-220 ellipsometer manufactured by Nippon Spectrophotometer Co., Ltd.

[0485] Next, a phase retardation layer forming composition (1) for an in-plane phase retardation layer was applied to the obtained photo-aligned film using a die-coating machine. After heating and drying at 120°C for 2 minutes, the film was cooled to room temperature to obtain a dried film. Then, the dried film was irradiated with a high-pressure mercury lamp under a nitrogen atmosphere at an exposure dose of 500 mJ / cm. 2 Ultraviolet light (365nm reference) is used to form an in-plane retardation layer, which is formed by curing a polymerizable liquid crystal compound in a horizontally oriented state relative to the substrate plane. This results in an in-plane retardation film A1 consisting of a substrate (PET film), a photoalignment film, and the in-plane retardation layer. The thickness of the in-plane retardation layer, measured using a LEXTOLS4100 laser microscope manufactured by Olympus Corporation, is 2.0 μm. The indentation modulus of the in-plane retardation layer, measured using the method described later, is 2100 MPa, and the in-plane average refractive index of the in-plane retardation layer is 1.59. Furthermore, the angle of the slow axis of the in-plane retardation layer relative to the width direction of the in-plane retardation film A1 when viewed from the in-plane retardation layer side of the in-plane retardation film A1 with the substrate is 15°.

[0486] The surface of the in-plane retardation film A1 with a substrate was corona treated, and then bonded to glass using a 25μm pressure-sensitive adhesive manufactured by LINTEC. The PET film was then peeled off. The in-plane retardation value was measured using a KOBRA-WR manufactured by Oji Measurement & Control Co., Ltd. It should be noted that the in-plane retardation values ​​for light with wavelengths of 450nm, 550nm, and 650nm were calculated using Cauchy's dispersion formula derived from the measurement results of the in-plane retardation values ​​for light with wavelengths of 448.2nm, 498.6nm, 548.4nm, 587.3nm, 628.7nm, and 748.6nm.

[0487] The result is that the in-plane phase difference values ​​are Re(450) = 122 nm, Re(550) = 140 nm, and Re(650) = 144 nm. The relationship between the in-plane phase difference values ​​at each wavelength is shown below, and the in-plane phase difference layer exhibits inverse wavelength dispersion.

[0488] Re(450) / Re(550)=0.87

[0489] Re(650) / Re(550)=1.03

[0490] (In the formula, Re(450) represents the in-plane phase difference for light with a wavelength of 450nm, Re(550) represents the in-plane phase difference for light with a wavelength of 550nm, and Re(650) represents the in-plane phase difference for light with a wavelength of 650nm.)

[0491] The in-plane phase difference layer is a positive A plate that satisfies nx>ny≈nz. It should be noted that the results of measuring the phase difference value Rth(λ) in the thickness direction at each wavelength are Rth(450)=61nm, Rth(550)=70nm, and Rth(650)=72nm.

[0492] (Fabrication of thickness-direction phase retardation film C with substrate)

[0493] While transporting a 500mm wide × 100m roll of biaxially stretched polyethylene terephthalate (PET) film (manufactured by Diafoil Mitsubishi Resin Co., Ltd.) with a thickness of 100μm at a speed of 4m / min, a plasma treatment device was used to treat the film once with an output power of 0.4kW. An orientation polymer composition was coated onto the plasma-treated surface using a die coater and dried at 90°C for 1 minute. The thickness of the resulting orientation film was measured using a laser microscope, and the result was 30nm. Next, a phase difference layer forming composition (2) for phase difference in the thickness direction was coated onto the orientation film using a die coater, and after drying at 90°C for 1 minute, the dried film was irradiated with a high-pressure mercury lamp under a nitrogen atmosphere with an exposure dose of 1000mJ / cm. 2 Ultraviolet light (based on 365nm) was used to obtain a thickness-direction retardation film C consisting of a substrate (PET film), an alignment film, and a thickness-direction retardation layer. The thickness of the thickness-direction retardation layer was measured using a laser microscope, and the result was a thickness of 385nm. The indentation modulus of the thickness-direction retardation layer, measured using the method described later, was 2900MPa, and the in-plane average refractive index of the thickness-direction retardation layer was 1.50. The phase difference value was measured using a KOBRA-WR manufactured by Oji Measurement Machine Co., Ltd. The result was Re(550) = 1nm, Rth(550) = -60nm, which is a positive C-plate satisfying nx≈ny<nz. It should be noted that since the phase difference value of the PET film at a wavelength of 550nm is approximately 0, it has no effect on this optical property.

[0494] (Fabrication of CA1 phase retardation film with substrate)

[0495] Next, a photo-alignment film forming composition was coated onto the surface of the thickness direction retardation layer side of the thickness direction retardation film C with the substrate obtained above using a die-coating machine. The resulting coated film was dried at 120°C for 2 minutes and then cooled to room temperature to form a dried film. Subsequently, a UV irradiation device (SPOT CURE SP-9; manufactured by USHIO Electric Co., Ltd.) was used with a cumulative light intensity of 100 mJ / cm². 2 The cumulative light intensity at a wavelength of 313 nm in air was subjected to polarized UV exposure at 165° relative to the width direction to obtain an optical alignment film. The thickness of the optical alignment film was measured to be 100 nm using an M-220 ellipsometer manufactured by Nippon Spectrophotometer Co., Ltd.

[0496] On the obtained photo-aligned film, the aforementioned phase retardation layer forming composition (1) for in-plane phase retardation layer is coated using a die-coating machine to form a coated film. The coated film is then heated and dried at 120°C for 2 minutes, and then cooled to room temperature to obtain a dried film. Then, the dried film is irradiated with a high-pressure mercury lamp (USHIO Electric Co., Ltd. "Unicure VB-15201BY-A") under a nitrogen atmosphere with an exposure dose of 500 mJ / cm². 2 Ultraviolet light (365nm reference) was used to form an in-plane retardation layer, which was formed by curing a polymeric liquid crystal compound in a horizontally oriented state relative to the substrate. This resulted in a substrate-based retardation film CA1, consisting of a substrate, an alignment film, a thickness-direction retardation layer, a photoalignment film, and an in-plane retardation layer. The in-plane retardation layer had a Re(550) of 140nm, an Rth(550) of 70nm, and a film thickness of 2.0μm as measured using a LEXTOLS4100 laser microscope manufactured by Olympus Corporation. Furthermore, the slow axis of the in-plane retardation layer, when viewed from the in-plane retardation layer side, was 165° relative to the width direction of the substrate-based retardation film CA1.

[0497] (Fabrication of CA2 phase retardation film with substrate)

[0498] In the fabrication of the photo-alignment film, the amount and angle of polarized ultraviolet light irradiation are adjusted, thereby changing the angle of the slow axis of the in-plane retardation layer relative to the width direction of the retardation film when viewed from the side of the in-plane retardation layer to 75°. In addition, the retardation film CA2 with a substrate is fabricated in the same way as the retardation film CA1 with a substrate.

[0499] (Fabrication of optical laminates)

[0500] Corona treatment was performed on the surface of the reflective polarizer 1. Adhesive composition A was applied to the corona-treated surface of the reflective polarizer 1 using a coating machine (a bar coater manufactured by Daiichi Rika Co., Ltd.) to form a layer of adhesive composition A. Then, corona treatment was performed on the surface of the in-plane retardation layer side of the in-plane retardation film A1 with a substrate prepared above. This corona-treated surface was then bonded to the layer of adhesive composition A using an adhesive bonding device ("LPA3301" manufactured by FUJIPLA Co., Ltd.). A cumulative light intensity of 1600 mJ / cm² was applied from the substrate side using an ultraviolet irradiation device with a conveyor belt (using "V-lamp" manufactured by Fusion UV Systems Co., Ltd.) in the wavelength region of 395–445 nm (UVV region). 2 Visible light is used to cure the adhesive, thereby obtaining laminate A-2. At this time, it is carried out in such a way that the angle between the transmission axis of the reflective polarizer 1 and the slow axis of the in-plane phase difference layer is 15°.

[0501] Next, the in-plane phase retardation layer side surface of the phase retardation film CA1 with substrate and the in-plane phase retardation layer side surface of the phase retardation film CA2 with substrate are bonded together using adhesive composition A in the same manner as described above, forming a laminate B-2. At this time, the angle between the slow axes of the in-plane phase retardation layers of the phase retardation film CA1 and the phase retardation film CA2 with substrate is 60°.

[0502] The substrate is peeled off from the CA1 side of the retardation film with substrate from laminates A-2 and B-2 (the alignment film is still retained), and their surfaces are bonded together using adhesive composition A in the same manner as described above. At this time, the slow axis of the in-plane retardation layer on the linear polarizer side of laminate B-2 is aligned with the slow axis of the in-plane retardation layer in laminate A-2. In the resulting laminate, the angle between the transmission axis of reflective polarizer 1 and the slow axis of λ / 2 portion is 15°, the angle between the transmission axis of reflective polarizer 1 and the slow axis of λ / 4 portion is 75°, and the angle between the slow axis of λ / 2 portion and the slow axis of λ / 4 portion is 60°.

[0503] Peel the spacer from one side of the adhesive sheet (2) and laminate it onto the side of the reflective polarizer 1 of the resulting laminate. Peel the remaining spacer from the opposite side of the adhesive sheet (2) and laminate it onto the side of the second protective layer of the absorptive polarizer 2, thus forming an optical laminate (4). It should be noted that the laminates are aligned in such a way that the reflection axis of the reflective polarizer 1 coincides with the absorption axis of the absorptive polarizer.

[0504] It should be noted that the thickness of the adhesive layer obtained by curing the above adhesive composition A was measured, and the result was that the thickness was 1.5 μm.

[0505] (Example 5)

[0506] Except for changing the absorptive polarizer 2 to the absorptive polarizer 1, the optical laminate (5) is made in the same manner as in Example 4.

[0507] (Example 6)

[0508] (Fabrication of CA4 phase retardation film with substrate)

[0509] Except that the angle of the slow axis of the in-plane retardation layer relative to the width direction of the retardation film when viewed from the side of the in-plane retardation layer is changed to 75°, the substrate-bearing retardation film CA4 is manufactured in the same manner as the substrate-bearing retardation film CA1 of Example 4.

[0510] (Fabrication of optical laminate (6))

[0511] The surface of the reflective polarizer 1 is bonded to the surface of the in-plane retardation layer side of the retardation film CA4 with substrate using adhesive composition A in the same manner as described in Example 4, forming a laminate A-12. In this case, the angle between the transmission axis of the reflective polarizer 1 and the slow axis of the in-plane retardation layer of the retardation film CA4 with substrate is 75°.

[0512] Next, on the surface after the substrate has been peeled off from the laminate A-12 (the alignment film is still retained), the surface of the in-plane retardation layer of another in-plane retardation film CA4 with a substrate is bonded using adhesive composition A in the same manner as described above. At this time, the angle between the transmission axis of the reflective polarizer and the slow axis of the in-plane retardation layer of the in-plane retardation film CA4 with a substrate is 75°.

[0513] After peeling off the substrate (with the alignment film still retained) on the thickness direction side of the resulting laminate, the surface of the in-plane phase retardation layer side of the phase retardation film A1 with the substrate is bonded using adhesive composition A in the same manner as described above to obtain the laminate. In this case, the angle between the transmission axis of the reflective polarizer and the slow axis of the in-plane phase retardation layer of the in-plane phase retardation film is 15°.

[0514] Therefore, the angle between the transmission axis of the reflective polarizer and the slow axis of the λ / 2 section is 75°, the angle between the transmission axis of the linear polarizer and the slow axis of the λ / 4 section is 15°, and the angle between the slow axis of the λ / 2 section and the slow axis of the λ / 4 section is 60°.

[0515] Peel the spacer from one side of the adhesive sheet (2) and laminate it onto the side of the reflective polarizer 1 of the resulting laminate. Peel the remaining spacer from the opposite side of the adhesive sheet (2) and laminate it onto the side of the second protective layer of the absorptive polarizer 2, thus forming an optical laminate (6). It should be noted that the laminates are aligned in such a way that the reflection axis of the reflective polarizer 1 coincides with the absorption axis of the absorptive polarizer.

[0516] (Example 7)

[0517] Except that the absorptive polarizer (2) is replaced by the absorptive polarizer (1), the optical laminate (7) is made in the same manner as in Example 6.

[0518] The conditions and results are shown in Tables 3 and 4.

[0519] (evaluate)

[0520] (Determination of visibility-corrected polarization degree Py for absorptive and reflective polarizers)

[0521] Eight sections of 30mm × 30mm were randomly cut from the prepared absorptive polarizers 1 and 2 and reflective polarizer 1. An alkali-free glass plate (Corning Corporation trade name "Eagle XG", thickness 0.7mm) was then bonded to the plate with an adhesive layer (3) to obtain the test sample. The test sample was placed in a spectrophotometer with an integrating sphere (Nippon Spectrophotometer Co., Ltd. "V7100", 2-degree field of view; C light source) to measure Py. The test sample was placed with incident light coming from the side opposite to the alkali-free glass plate. The standard deviation of each Py value was calculated and recorded in Table 3.

[0522] It should be noted that the degree of polarization is defined by the following formula:

[0523] Degree of polarization (λ)=100×(Tp(λ)-Tc(λ)) / (Tp(λ)+Tc(λ))

[0524] Tp(λ) is the transmittance (%) measured based on the relationship between incident linearly polarized light with wavelength λnm and a parallel Nicol prism, and Tc(λ) is the transmittance (%) measured based on the relationship between incident linearly polarized light with wavelength λnm and an orthogonal Nicol prism.

[0525] The visibility-corrected polarization degree Py is a value obtained by correcting the polarization degree (λ) calculated at each wavelength using the 2-degree field of view (C light source) of JIS Z 8701. Py is measured every 5 nm in the wavelength range of 380–780 nm.

[0526] (In-plane average refractive index of the cured layer (adhesive layer) of adhesive composition A)

[0527] On one side of a stretched norbornene resin film ("ZEONOR film" manufactured by ZEON Corporation of Japan), adhesive composition A is applied using an adhesive coating apparatus (manufactured by Daiichi Rikan Kagaku Co., Ltd.) to achieve a thickness of approximately 30 μm after ultraviolet irradiation. An ultraviolet irradiation apparatus (manufactured by Fusion UV Systems Co., Ltd.) is used with a cumulative light intensity of 600 mJ / cm². 2 (UV-B) ultraviolet light was used to irradiate the adhesive layer to obtain an adhesive layer. The norbornene resin film was peeled off from the obtained adhesive layer, and the refractive index (589 nm) of the adhesive layer was measured using a multi-wavelength Abbe refractometer (ATAGO Corporation "DR-M2") at 25°C. This value was set as the in-plane average refractive index of the cured layer of adhesive composition A.

[0528] (In-plane average refractive index of the in-plane phase retardation layer and the thickness-direction phase retardation layer)

[0529] The phase difference layer sides of each optical laminate were bonded to a glass plate (0.7 mm thick, Corning "Eagle XG") using a 25 μm thick acrylic adhesive. Using this laminate, the in-plane refractive indices nx and ny at 589 nm were measured using a KOBRA-WR instrument manufactured by Oji Measurement Equipment Co., Ltd. The in-plane average refractive index n was calculated using nx and ny according to the following formula.

[0530] n = (nx + ny) / 2

[0531] (In the formula, nx represents the refractive index along the slow axis in the film, ny represents the refractive index along the fast axis in the film, and n represents the in-plane average refractive index.)

[0532] (Indented elastic modulus)

[0533] (Production of the experimental film)

[0534] A portion of each optical laminate obtained in the examples and comparative examples was cut and resin-embedded to observe the cross-section in the thickness direction. Then, a glass blade and a SYM blade (SYNTEC "SYM2045 Ultra Cryo / Wet" (model: SYM2045C)) were mounted in a microtome (Leica EM FC7) equipped with a Leica cryosectioning system. After the resin-embedded film, glass blade, and SYM blade reached a cooling temperature of -100°C, they were left to stand for 10 minutes. Subsequently, the glass blade was used to scan the surface of the optical laminate in a vertical direction, cutting at least 100 μm along the depth direction of the test piece (relative to the plane of the optical laminate) after reaching the surface of the resin-embedded optical laminate. Then, using the SYM blade, the cutting was performed at 100 nm / 0.6 mm. -1 The spacing is cut to a depth of 1μm or more, followed by a cutting speed of 50nm / 0.6mm. -1 The spacing is cut to a depth of 0.5μm or more, and finally at 30nm / 0.3mm. -1The spacing was cut to a depth of 0.3 μm or more. The resulting test piece was left to stand in a nitrogen atmosphere until it returned to room temperature. The cut section was used as the observation surface, and the resulting test piece was placed in an SPM (Bruker Corporation; Dimension Icon). It should be noted that the cut section (observation surface) was used as the surface along the slow axis of the first in-plane phase difference layer, and the indentation elastic modulus of the in-plane phase difference layer, the thickness direction phase difference layer, the adhesive layer and the adhesive layer (1) and (2) were obtained according to the following steps. The indentation elastic modulus of the in-plane phase difference layer was the value obtained by measuring the first in-plane phase difference layer, that is, the indentation elastic modulus in the section along the slow axis. In addition, the cured layer in the liquid crystal polarizer was measured with the section along each transmission axis as the observation surface.

[0535] (Obtaining the indentation elastic modulus based on SPM)

[0536] The mechanical properties of the specimen cross-section were evaluated under the following conditions, and the indentation modulus was calculated based on the JKR (Johnson-Kendall-Roberts) theory and the DMT (Derjaguim-Muller-Toporov) theory. Specifically, firstly, the displacement of the piezoelectric scanner and the warping of the cantilever were measured during the contact process between the cantilever probe and the specimen to obtain a curve (force curve) representing the relationship between the load F and the specimen deformation δ. At each measurement point, for the pull-back process of the obtained force curve (from the time point when the cantilever probe is pressed into the specimen to the time point of the preset maximum load until the probe completely leaves the specimen surface), an analysis based on the DMT theory formula was first performed to obtain the indentation modulus value. For layers with an indentation modulus less than 1000 MPa, the indentation modulus obtained by the analysis based on the JKR theory formula was used. In this embodiment, the indentation modulus based on the JKR theory formula was used only for the adhesive layers (1) and (2).

[0537] In the analysis, using the analysis software (NanoScope Analysis ver. 2.00), and with the DMT theoretical formula, the minimum to maximum F value during the pull-back process of the force curve was set to 0 to 1, and fitted within the range of 0.05 to 0.7 to calculate the indentation modulus. Alternatively, using the JKR theoretical formula, the indentation modulus was calculated by fitting within the range of the minimum F value during the pull-back process to 0nN. For each layer constituting the laminate, the indentation modulus was calculated above 1024 points, and the average indentation modulus was calculated and set as the indentation modulus of each layer.

[0538] The cantilever used was an RTESA-300 (manufactured by Bruker; nominal spring constant 40 N / m, nominal probe tip radius 8 nm). The spring constant of the cantilever was calculated using the Sader method (Reference A) within the SPM device. The probe tip radius of the cantilever was calculated using the reconstruction method (Reference B) within the SPM device at a distance of 2 nm from the tip. Only cantilevers with values ​​below 15 nm were used in the measurement.

[0539] In cases where a layer with an indentation modulus less than 1000 MPa, obtained from analysis based on the DMT theoretical formula, was detected, the cantilever was changed to an RTESA-150 (manufactured by Bruker; nominal spring constant 5 N / m, nominal probe tip radius 8 nm), and the layer was measured again. Except for the cantilever spring constant and the probe tip diameter, which were calculated using the probe tip diameter value at a position on the average specimen deformation value from the tip, the same method as described above was used. Here, the average δ value was obtained by calculating the average of 1024 or more indentations with an upper limit of 50 nm. The maximum load was set to a value where the average δ value reached 3 nm or more, and measurements were performed. Furthermore, the peak force amplitude, which is the distance between the maximum and minimum heights in the indentation direction scan of the cantilever probe, was set to a value within 5 times the pull-back process of the force curve, and measurements were performed.

[0540] Force curves were obtained using Peak Force QNM (Quantitative Nanomechanical Mapping) mode. The measurement conditions using RTESA-300 and RTESA-150 are shown below. Peak Force Amplitude is the input value.

[0541] (Reference A) Sader JE, Sanelli JA, Adamson B.D., Monty JP, Wei X., Crawford SA, Rev. Sci. Instrum., 2012, Vol. 83, pp. 103705-1 to 103705-16

[0542] (Reference B) ISO 13095:2014

[0543] <Measurement conditions using RTESPA-300>

[0544] Cantilever: RTESPA-300 (Bruker)

[0545] Device: Dimension Icon (Bruker)

[0546] Measurement mode: Peak Force QNM

[0547] Measurement atmosphere: 24℃ / atmospheric / humidity 41%

[0548] Measurement range: 10μm × 10μm

[0549] Number of measurement points: 256 × 256 points

[0550] Cantilever movement speed: 0.2Hz

[0551] Maximum load: 40nN

[0552] Peak Force Frequency: 1kHz

[0553] Peak force amplitude: 30nm

[0554] Feedback Gain: Auto

[0555] <Measurement conditions using RTESPA-150>

[0556] Cantilever: RTESPA-150 (Bruker)

[0557] Device: Dimension Icon (Bruker)

[0558] Measurement mode: Peak Force QNM

[0559] Measurement atmosphere: 24℃ / atmospheric / humidity 41%

[0560] Measurement range: 1μm × 1μm

[0561] Number of measurement points: 32×32 points

[0562] Cantilever movement speed: 0.1Hz

[0563] Maximum load: 0.5nN

[0564] Peak Force Frequency: 1kHz

[0565] Peak force amplitude: 150nm

[0566] Feedback Gain: Auto

[0567] (Evaluation of the standard deviation σ of the reflectance of optical laminates (1), (4) and (5))

[0568] Using a Konica Minolta Cm2600d, the SCI reflectance of the optical laminates (1), (4), and (5) obtained in Example 1, Comparative Example 1, and Reference Example was measured. During the measurement, the obtained optical laminates were cut to a size 160 mm parallel to the transmission axis of the polarizer and 100 mm parallel to the absorption axis. A 25 μm thick acrylic adhesive layer was sandwiched between the phase difference layer and a glass plate (0.7 mm thick, Corning Eagle XG). The optical laminate with the glass plate was placed on top of a reflector (reflectance: 96% or higher, diffuse reflectance: 9% or lower), with water sandwiched between the layers. Test samples were prepared by layering the reflector / water / glass plate / adhesive layer / optical laminate and then measured. Regarding the measurement locations within the sample surface, a total of 4 points were measured at positions 10 mm from each of the long and short sides relative to the corners of the sample. In addition, 1 point was measured at a position 80 mm from each of the long and short sides relative to the corners of the sample surface, and 1 point was measured at a position 50 mm from each of the long and short sides relative to the corners of the sample surface. A total of 5 points were measured, and the standard deviation of the obtained SCI reflectance was calculated and recorded in Table 3.

[0569] (Evaluation of the standard deviation σ of the reflectance of optical laminates (2) and (3))

[0570] The SCI reflectance of the optical laminates (2) and (3) obtained in Examples 2 and 3 was measured using a "Cm2600d" manufactured by Konica Minolta. During the measurement, a 160 mm section parallel to the transmission axis of the optical laminate and a 100 mm section parallel to the reflection axis were cut from the optical laminate. An acrylic adhesive layer with a thickness of 25 μm was sandwiched between the laminates, and the side opposite to the phase difference layer laminate was attached to a black acrylic resin plate. The optical laminate (1) was then cut to a size 160 mm parallel to the transmission axis of the liquid crystal polarizer and 100 mm parallel to the absorption axis. An acrylic adhesive layer with a thickness of 25 μm was sandwiched between the laminate and the phase difference layer. The laminate was then attached to a glass plate (0.7 mm thick, Corning "Eagle XG"). The resulting laminate was used as a filter. Measurements were performed in a state where the laminate was composed of a black acrylic resin plate / adhesive layer / optical laminate (2) or (3) / filter (glass / adhesive layer / optical laminate (1)). Within the sample surface, for the measurement location, a total of 4 points were measured at 10 mm along the long and short sides of the sample corner. In addition, 1 point was measured at 80 mm along the long side and 50 mm along the short side of the sample corner, for a total of 5 points. The standard deviation of the SCI reflectance was calculated and recorded in Table 3.

[0571] [Table 3]

[0572]

[0573] [Table 4]

[0574]

[0575] Explanation of reference numerals in the attached figures

[0576] 1 Image display device, 10 Optical laminate, 100 First polarizer A, 120A First linear polarizer, 120B Second linear polarizer, 200 Adhesive layer D, 300 λ / 2 section, 310 In-plane phase retardation layer (phase retardation layer), 320 Thickness direction phase retardation layer (phase retardation layer), 400 λ / 4 section, 410 In-plane phase retardation layer, 420 Thickness direction phase retardation layer, 330 Adhesive layer A, 430 Adhesive layer C, 500 Adhesive layer B, 600 Phase retardation layer laminate, 900 Image display element.

Claims

1. An optical laminate, which comprises a first linear polarizing plate and a phase difference layer laminate, the phase difference layer laminate has 3 or more phase difference layers, at least 3 of the 3 or more phase difference layers are in-plane phase difference layers, the first linear polarizing plate is either an absorption-type polarizing plate or a reflection-type polarizing plate, a standard deviation σ of a visibility correction degree of polarization Py in the in-plane direction of the first linear polarizing plate is 0.001% or more.

2. The optical laminate according to claim 1, wherein the absorption-type polarizing plate is a cured product of a dichroic dye and a polymerizable liquid crystal compound that has been oriented.

3. The optical laminate according to claim 1 or 2, wherein an indentation elastic modulus of the absorption-type polarizing plate is 10,000 MPa or less.

4. The optical laminate according to claim 1 or 2, wherein the in-plane phase difference layer satisfies the following condition: 100 nm ≤ Re(550) ≤ 180 nm.

5. The optical laminate according to claim 1 or 2, wherein the in-plane phase difference layer has a reverse wavelength dispersion.

6. The optical laminate according to claim 1 or 2, wherein the in-plane phase difference layer satisfies the following condition: Re(450) / Re(550) ≤ 1.

00.

7. The optical laminate according to claim 1 or 2, wherein the phase difference layer laminate further has at least one thickness direction phase difference layer.

8. The optical laminate according to claim 7, wherein the phase difference layer laminate has, in order from the first linear polarizing plate side, a first in-plane phase difference layer, a second in-plane phase difference layer, and a third in-plane phase difference layer, and the at least one layer having a phase difference in the thickness direction is disposed between the first in-plane phase difference layer and the second in-plane phase difference layer.

9. The optical laminate according to claim 8, wherein a cured product layer of a curable energy ray adhesive is disposed between the second in-plane phase difference layer and the third in-plane phase difference layer, and a refractive index of the cured product layer is 1.50 or more.

10. The optical laminate according to claim 1 or 2, wherein the phase difference layer laminate further has a bonding layer provided between at least one pair of the phase difference layers.

11. The optical laminate according to claim 10, wherein at least one of the bonding layers is a cured product layer of a curable energy ray adhesive or a curable energy ray adhesive.

12. The optical laminate according to claim 10, wherein at least one of the bonding layers is a cured product layer of a curable energy ray adhesive.

13. The optical laminate according to claim 1 or 2, wherein at least one pair of phase difference layers adjacent to each other are laminated without a bonding layer interposed therebetween.

14. The optical laminate according to claim 13, wherein the phase difference layer laminate further has at least one thickness direction phase difference layer, and the at least one pair of phase difference layers adjacent to each other that are laminated without a bonding layer interposed therebetween are a combination of an in-plane phase difference layer and a thickness direction phase difference layer.

15. The optical laminate according to claim 10, wherein The press-in elastic modulus of all the bonding layers provided between the phase difference layers of the phase difference layer laminate is 3 MPa or more.

16. The optical laminate according to claim 10, wherein The average of the thicknesses of all the bonding layers present in the bonding layers within the phase difference layer laminate is 7 μm or less.

17. The optical laminate according to claim 1 or 2, wherein The first linear polarizing plate is a reflective polarizing plate.

18. The optical laminate according to claim 1 or 2, wherein A second linear polarizing plate is further provided between the phase difference layer laminate and the first linear polarizing plate or on the side opposite to the phase difference layer laminate with respect to the first linear polarizing plate, the second linear polarizing plate being the other of an absorptive polarizing plate or a reflective polarizing plate.

19. An image display device provided with the optical laminate according to claim 1 or 2 and an image display element.

Images