Optical laminate

Abstract

An optical laminate is provided that reduces the thickness increase of a linear polarizer in humid and hot environments. The optical laminate sequentially comprises a polarizer, a first bonding layer, and a phase retardation portion comprising at least one liquid crystal phase retardation layer. The polarizer, starting from the side opposite to the phase retardation portion, sequentially comprises a first protective film, a linear polarizer, a first resin layer, and a second protective film. The polarizer further comprises a second resin layer disposed between the first resin layer and the first bonding layer.

Description

Technical Field

[0001] This invention relates to optical laminates. Background Technology

[0002] Previously, it was known to have a linear polarizer comprising a first protective film, a polyvinyl alcohol-based linear polarizer, a resin layer such as a water-based adhesive, a triacetyl cellulose-based film as a second protective film, an adhesive layer such as an adhesive, and a circular polarizer with a phase difference portion.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2024-146782 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in humid and hot environments, acidic components such as those from the adhesives used in the bonding layer, acetic acid produced by the hydrolysis of the triacetyl cellulose membrane, and boric acid crosslinking can be transferred from other layers to the linear polarizer, thus increasing the thickness of the linear polarizer.

[0008] The present invention was made in view of the above-mentioned problems, and its object is to provide an optical laminate that can reduce the increase in thickness of linear polarizers in humid and hot environments.

[0009] Methods for solving problems

[0010] [1] An optical laminate, comprising sequentially a polarizing plate, a first bonding layer, and a phase difference portion comprising at least one liquid crystal phase difference layer,

[0011] The polarizing plate, starting from the side opposite to the phase difference portion, sequentially comprises a first protective film, a linear polarizer, a first resin layer, and a second protective film.

[0012] The polarizing plate further includes a second resin layer disposed between the first resin layer and the first bonding layer.

[0013] [2] According to the optical laminate described in [1], the second resin layer is in contact with the second protective film.

[0014] [3] According to the optical laminate described in [1], the second resin layer is in contact with the phase difference side of the second protective film.

[0015] [4] An optical laminate according to any one of [1] to [3], wherein the second resin layer comprises a compound containing N atoms.

[0016] [5] According to the optical laminate described in [4], the second resin layer is a cured product of a polymeric composition comprising a polymeric compound and a photopolymerization initiator, wherein the N-atom-containing compound is a compound derived from the photopolymerization initiator.

[0017] [6] According to the optical laminate described in [4] or [5], the mass ratio of the N atom in the thickness direction section of the second resin layer to the total mass of the N atom and the O atom is 1 to 10 mass.

[0018] [7] According to any one of [4] to [6], the product of the mass ratio (mass%) of N atoms in the thickness direction section of the second resin layer to the total mass of N atoms and O atoms and the thickness (μm) of the second resin layer is 3 to 50 (mass%·μm).

[0019] [8] An optical laminate according to any one of [1] to [7], wherein the thickness of the second resin layer is 0.1 to 10 μm.

[0020] [9] An optical laminate according to any one of [1] to [8], wherein the second protective film is a triacetyl cellulose resin film.

[0021]

[10] An optical laminate according to any one of [1] to [9], wherein the phase difference portion comprises a first liquid crystal phase difference layer and a second liquid crystal phase difference layer.

[0022]

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

[10] satisfies the following relationship between equations (1) and (2).

[0023] 100nm≤Re(550)≤180nm (1)

[0024] Re(450) / Re(550)≤1.00 (2)

[0025] [In equations (1) and (2),]

[0026] Re(450) represents the in-plane phase difference value in nm for light with a wavelength of 450 nm.

[0027] Re(550) represents the in-plane phase difference value in nm for light with a wavelength of 550 nm.

[0028]

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

[11] , wherein the first bonding layer is a cured product of an active energy ray curable adhesive.

[0029]

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

[12] , wherein the first bonding layer is a cured product of an active energy ray curable adhesive.

[0030]

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

[13] , wherein the linear polarizer is a polarizer formed by oriented iodine adsorption onto a polyvinyl alcohol-based resin film.

[0031]

[15] An image display device comprising an optical laminate and an image display unit as described in any one of [1] to

[14] .

[0032] Invention Effects

[0033] According to the present invention, an optical laminate capable of reducing the thickness increase of linear polarizers in humid and hot environments is provided. Attached Figure Description

[0034] Figure 1 This is a schematic cross-sectional view showing the first embodiment of the optical laminate 10.

[0035] Figure 2 This is a schematic cross-sectional view showing the second embodiment of the optical laminate 10.

[0036] Explanation of reference numerals in the attached figures

[0037] 10… Optical laminate, 30… First liquid crystal phase retardation layer, 50… Second liquid crystal phase retardation layer, 130… First resin layer, 140… Second resin layer, 150… First bonding layer, 180… First protective film, 190… Second protective film, 200… Polarizing plate, 220… Linear polarizer, 300… Phase retardation section. Detailed Implementation

[0038] (Optical laminate 10)

[0039] like Figure 1 and Figure 2 As shown, the optical laminate 10 of the first embodiment and the second embodiment includes a polarizer 200, a first bonding layer 150 and a phase difference portion 300, and can function as a circular polarizer.

[0040] (Polarizing plate 200)

[0041] The polarizer 200 includes, in sequence from the side opposite to the phase difference portion 300, a first protective film 180, an upper bonding layer 210, a linear polarizer 220, a first resin layer 130, and a second protective film 190. It also includes a second resin layer 140 on the side of the second protective film at the phase difference portion 300 or between the first resin layer 130 and the second protective film 190.

[0042] (Linear polarizer 220)

[0043] Linear polarizers have the function of selectively transmitting linearly polarized light in a certain direction from unpolarized light such as natural light. Examples of linear polarizers include polyvinyl alcohol-based polarizers (hereinafter also referred to as "polarizers") formed by uniaxial stretching in which iodine and organic dichroic dyes are impregnated in polymers such as PVA, and cured films containing dichroic pigments and polymeric liquid crystal compounds that have been oriented.

[0044] The polarization performance of a linear polarizer can be measured using a spectrophotometer. For example, in the visible light range (wavelengths 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 (orientation direction) using the two-beam method. Regarding the polarization performance in the visible light range, the single-unit transmittance and degree of polarization at each wavelength are calculated using the following equations (Equation 1) and (Equation 2). Visibility correction is then performed using the 2-degree field of view (C-light source) of the JIS Z8701, thereby allowing the calculation of the single-unit transmittance (Ty) and the degree of polarization (Py) corrected for visibility. Furthermore, based on the similarly measured transmittance, the L value is calculated using the color matching function of the C-light source. * a * b * (CIE) Colorimetric a in the color system * and b * This allows us to obtain 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). * and b * The closer the value is to 0, the more neutral the hue can be.

[0045] Monomer transmittance (%) = (T1 + T2) / 2 ··· (Equation 1)

[0046] Degree of polarization (%) = (T1-T2) / (T1+T2)×100 ···(Equation 2)

[0047] The visibility-corrected polarization degree Py of a 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 is suitable for use in liquid crystal displays. Increasing the visibility-corrected polarization degree Py of a linear polarizer is advantageous in improving the anti-reflective function of optical laminates. If the visibility-corrected polarization degree Py is less than 80%, it may sometimes fail to perform its anti-reflective function when used as an anti-reflective film.

[0048] A higher transmittance Ty of the visibility-correcting monomer in a linear polarizer increases the clarity of white displays. However, as shown in Equations (1) and (2), excessively increasing the transmittance leads to a decrease in polarization degree. Therefore, a transmittance of 30% or more and 60% or less is preferred, 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 45% or less, and most preferably 41% or more and 43% or less. If the transmittance Ty of the visibility-correcting monomer is too high, the polarization degree Py becomes too low, sometimes resulting in insufficient anti-reflective function when used as an anti-reflective film.

[0049] <Polarizer>

[0050] A polyvinyl alcohol (PVA) polarizing film, which is uniaxially stretched while impregnated with a polymer such as a polyvinyl alcohol (PVA) resin film, is typically manufactured through the following steps: uniaxial stretching of the PVA resin film; dyeing the PVA resin film with a dichroic pigment such as iodine to adsorb the pigment; treating the PVA resin film with the adsorbed pigment using a crosslinking agent such as a boric acid aqueous solution; and washing with water after treatment with the crosslinking agent such as a boric acid aqueous solution. The polarizing film may contain a crosslinking agent.

[0051] 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.

[0052] Uniaxial stretching of polyvinyl alcohol (PVA)-based resin films can be performed before, simultaneously with, or after dyeing with dichroic pigments. When uniaxial stretching is performed after dyeing, it can be done before or during boric acid treatment. Of course, uniaxial stretching can also be performed in multiple stages as shown here. Uniaxial stretching can be performed by: stretching uniaxially along the film transport direction between rollers with different circumferential speeds; stretching uniaxially along the film transport direction using heated rollers; stretching along the width direction using a tenter frame, etc. Furthermore, uniaxial stretching can be performed by dry stretching in the atmosphere or by wet stretching while the PVA-based resin film is swollen using a solvent such as water. The stretching ratio is typically around 3 to 8 times. Alternatively, an aqueous solution containing PVA can be coated onto a thermoplastic resin film, dried, and then stretched together with the thermoplastic resin film using the methods described above.

[0053] The dyeing of polyvinyl alcohol (PVA) resin films using dichroic pigments can be carried out, for example, by immersing the PVA resin film in an aqueous solution containing a dichroic pigment. Specifically, iodine or dichroic organic dyes can be used as dichroic pigments. It should be noted that the PVA resin film is preferably pre-treated by immersion in water to induce swelling before dyeing.

[0054] When using iodine as a dichroic dye, the dyeing method typically involves impregnating a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide. The iodine content in this aqueous solution is typically approximately 0.01 to 1 part by weight relative to 100 parts by weight of water, and the potassium iodide content is typically approximately 0.5 to 20 parts by weight relative to 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is typically around 20 to 40°C. Furthermore, the impregnation time (dyeing time) in this aqueous solution is typically around 20 to 1,800 seconds.

[0055] On the other hand, when using dichroic organic dyes as dichroic pigments, a common dyeing method involves impregnating a polyvinyl alcohol-based resin film in an aqueous solution containing the water-soluble dichroic organic dye. The content of the dichroic organic dye in this aqueous solution is typically about 0.0001 to 10 parts by weight relative to 100 parts by weight of water, preferably 0.001 to 1 part by weight. This dye aqueous solution may contain inorganic salts such as sodium sulfate as dyeing auxiliaries. The temperature of the dichroic organic dye aqueous solution used in dyeing is typically about 20 to 80°C. Furthermore, the impregnation time (dyeing time) in this aqueous solution is typically about 10 to 1,800 seconds.

[0056] Boric acid treatment following dyeing with a dichroic pigment can be performed by immersing the dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid. The boric acid content in the aqueous solution is typically about 2 to 15 parts by weight relative to 100 parts by weight of water, preferably 5 to 12 parts by weight. When iodine is used as the dichroic pigment, the aqueous solution containing boric acid preferably contains potassium iodide. The potassium iodide content in the aqueous solution is typically about 0.1 to 15 parts by weight relative to 100 parts by weight of water, preferably 5 to 12 parts by weight. The immersion time in the aqueous solution containing boric acid is typically about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the aqueous solution containing boric acid is typically above 50°C, preferably 50 to 85°C, and more preferably 60 to 80°C.

[0057] Boric acid-treated polyvinyl alcohol (PVA) resin membranes are typically subjected to a water washing process. This washing can be performed, for example, by immersing the boric acid-treated PVA resin membrane in water. The water temperature during the washing process is typically around 5–40°C. Furthermore, the immersion time is typically around 1–120 seconds.

[0058] After washing, a drying process is performed to obtain a polarizing film. The drying process can be carried out using a hot air dryer or a far-infrared heater. The drying temperature is typically around 30–100°C, preferably 50–80°C. The drying time is typically around 60–600 seconds, preferably 120–600 seconds. Through the drying process, the moisture content in the polarizing film is reduced to a practical level. Its moisture content relative to the total mass of the polarizing film is typically around 5–20% by mass, preferably 8–15% by mass. If the moisture content is above 5% by mass, the polarizing film has sufficient flexibility, thus preventing damage or breakage after drying. Furthermore, if the moisture content is below 20% by mass, the polarizing film has sufficient thermal stability.

[0059] As described above, it is possible to manufacture polarizers formed by the adsorption and orientation of dichroic pigments on polyvinyl alcohol-based resin films.

[0060] (First protective film 180)

[0061] The first protective film 180 functions to protect the surface of the linear polarizer 220. The first protective film 180 is a resin film. The resin film can be a film existing as a monomer.

[0062] As a resin film, for example, a resin film with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and tensile strength can be used. The resin film can be a thermoplastic resin film. Specific examples of thermoplastic resins include: cellulose resins such as triacetyl cellulose resins; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; polyamide resins such as nylon and aromatic polyamides; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin resins having cyclic and norbornene structures (also called norbornene resins); (meth)acrylic resins such as polymethyl methacrylate; polyarylate resins; polystyrene resins; polyvinyl alcohol resins; and mixtures thereof. Thermoplastic resin films of this material are readily available on the market. In this specification, (meth)acrylic acid refers to either acrylic acid or methacrylic acid.

[0063] The thickness of the first protective film 180 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.

[0064] The first protective film 180 can be a stretched film. Examples of stretching processes include uniaxial stretching and biaxial stretching. Examples of stretching directions include: the mechanical flow direction (MD) of the unstretched film, a direction orthogonal to it (TD), and a direction oblique to the mechanical flow direction (MD). Biaxial stretching can be simultaneous biaxial stretching in two stretching directions, or sequential biaxial stretching where stretching occurs in a specified direction followed by stretching in other directions. The stretching process can be performed, for example, by using two or more pairs of clamping rollers with increased circumferential speed on the exit side to stretch along the length direction (mechanical flow direction: MD), or by using chucks to hold both ends of the unstretched film and expanding it along a direction orthogonal to the mechanical flow direction (TD). In this case, the phase difference and wavelength dispersion can be controlled by adjusting the film thickness or the stretching ratio. Furthermore, the wavelength dispersion value can be controlled by adding a wavelength dispersion modifier to the resin.

[0065] The first protective film 180 may contain any appropriate additives depending on the purpose. Examples of additives include: hindered phenolic, phosphorus, 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 additives may be appropriately determined based on the purpose and desired characteristics.

[0066] On the upper surface of the first protective film 180 (the side opposite to the phase difference portion), a surface treatment layer (coating) 110 may be provided to impart desired surface optical properties or other characteristics. For example, in Figure 1 In this protective film 180, a surface treatment layer 110 is provided on the upper surface (the side opposite to the phase difference portion). 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 for forming the surface treatment layer is not particularly limited, and known methods can be used. In addition, in order to improve the adhesion with the linear polarizer, the lower surface (the side facing the linear polarizer) of the first protective film 180 may be surface treated (e.g., corona treatment), or a thin layer such as an undercoat layer (also called an easy-to-adhere layer) may be formed.

[0067] (Second protective film 190)

[0068] The second protective film 190 functions to protect the surface of the linear polarizer 220. The second protective film 190 is a resin film. Examples of resin films are the same as those listed in the first protective film 180, and can be the same resin film as the first protective film, or they can be different resin films.

[0069] From the perspective of impact resistance, the second protective film 190 is suitable as a triacetyl cellulose resin film.

[0070] The thickness of the second protective film 190 may be the thickness described in the section on the first protective film 180.

[0071] (Upper bonding layer 210)

[0072] The upper bonding layer 210 bondes the first protective film 180 to the linear polarizer 220.

[0073] In this embodiment, the upper bonding layer 210 is an arbitrary component, and the first protective film 180 and the linear polarizer 220 can be in direct contact.

[0074] The upper bonding layer 210 can be an adhesive layer or a bonding agent layer; from the viewpoint of thinness, an adhesive layer is preferred.

[0075] The adhesive layer or bonding layer is not particularly limited and may utilize the layer exemplified in the second bonding layer described later.

[0076] (First resin layer 130 and second resin layer 140)

[0077] The first resin layer 130 is disposed between the linear polarizer 220 and the second protective film 190, and the second resin layer 140 is disposed between the first resin layer 130 and the first adhesive layer 150.

[0078] exist Figure 1 In the first embodiment shown, the second resin layer 140 is disposed between the second protective film 190 and the first adhesive layer 150. Figure 2 In the second embodiment shown, the second resin layer 140 is disposed between the first resin layer 130 and the second protective film 190.

[0079] The first resin layer 130 can be bonded to the linear polarizer 220 using adhesives or bonding agents, but is best suited for contact with the surface of the linear polarizer 220. Figure 1 In the middle, the first resin layer 130 can contact the second protective film 190, in Figure 2 In this process, the first resin layer 130 can contact the second resin layer 140.

[0080] Additionally, the second resin layer 140 can be adhered to the second protective film 190 using adhesives, bonding agents, etc., but is suitable for contact with the surface of the second protective film 190. For example... Figure 1 As shown, the second resin layer 140 can be in contact with the surface of the second protective film 190 on the phase difference portion 300 side, such as... Figure 2 As shown, the second resin layer 140 can be in contact with the surface of the second protective film 190 on the linear polarizer 220 side.

[0081] The first resin layer 130 and the second resin layer 140 are suitable as thermoplastic resin layers or cured resin layers. The first resin layer and the second resin layer can be thermoplastic resin layers or cured resin layers independently, respectively. However, from the viewpoint of reducing the increase in thickness of the linear polarizer in humid and hot environments, it is suitable for at least one to be a cured resin layer, and it is particularly suitable for the second resin layer to be a cured resin layer.

[0082] (Thickness of the first resin layer 130)

[0083] The thickness of the first resin layer 130 is not particularly limited, but it is suitable to be 0.01μm or more, 0.02μm or more, or 0.5μm or more. It can be less than 5μm, less than 3μm, less than 2μm, or less than 1μm.

[0084] (Thickness of the second resin layer 140)

[0085] The thickness of the second resin layer 140 is not particularly limited, but it is suitable to be 0.1μm or more, 0.5μm or more, 1.0μm or more, 1.5μm or more, or 2.0μm or more. It can be less than 10μm, less than 8μm, less than 7μm, less than 5μm, less than 4μm, or less than 3μm.

[0086] <Thermoplastic resin layer>

[0087] The resin layer can be a thermoplastic resin layer. The thermoplastic resin layer is obtained by coating a composition containing a thermoplastic resin and then drying it. For example, if the first resin layer is a thermoplastic resin layer, it can be formed by directly coating the above composition onto the surface of a linear polarizer 220 or similar material and then drying it as needed.

[0088] Examples of thermoplastic resins used in the thermoplastic resin layer include those described for the first protective film 180. Suitable thermoplastic resins are cyclic polyolefin resins and polyvinyl alcohol resins, with polyvinyl alcohol resins being particularly suitable.

[0089] The thermoplastic resin layer can be a water-based adhesive layer. Particularly when the first resin layer is a thermoplastic resin layer, from the viewpoint of improving the adhesion between the linear polarizer and the second resin layer or the second protective film, a water-based adhesive layer is suitable. The water-based adhesive layer can be formed from a water-based adhesive composition. Examples of water-based adhesive compositions include compositions formed by dissolving a polyvinyl alcohol-based resin or urethane resin as a main component in water, and compositions formed by dispersing a polyvinyl alcohol-based resin or urethane resin as a main component in water. The water-based adhesive composition may further contain curing components such as polyaldehydes, melamine compounds, zirconium oxide compounds, zinc compounds, glyoxal compounds, water-soluble epoxy resins, and crosslinking agents. Examples of water-based adhesive compositions include, for example, the adhesive compositions 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.

[0090] The thickness of the thermoplastic resin layer can be less than 5μm, less than 3μm, less than 1μm, or less than 0.5μm. Alternatively, it can be greater than 0.01μm or greater than 0.05μm.

[0091] <Curing Resin Layer>

[0092] The resin layer can be a cured resin layer. A cured resin layer is a cured layer of a curable composition containing active energy radiation-curable components. The cured resin layer can be formed by coating the above composition onto a support substrate, drying it as needed, and then heating or irradiating it with active energy radiation such as visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, gamma rays, or electron beams. The resulting cured resin layer is then bonded to a linear polarizer, a second protective film, etc., via an adhesive layer as needed, and then the support substrate is peeled off, thereby forming a cured resin layer in an optical laminate. Alternatively, the above composition can be directly coated onto the surface of a linear polarizer, a second protective film, etc., dried as needed, and then heated or irradiated with active energy radiation such as visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, gamma rays, or electron beams.

[0093] From the viewpoint of adhesion and productivity, the above-mentioned curing composition is preferably of the ultraviolet curing type, and preferably contains an active energy ray curing component and a photopolymerization initiator.

[0094] Examples of active energy ray curable components include cationic polymeric compounds and free radical polymeric compounds. Specific examples of cationic polymeric compounds include epoxy compounds having one or more epoxy groups within the molecule, oxetane compounds having one or more oxetane rings within the molecule, and vinyl compounds. Specific examples of free radical polymeric compounds include (meth)acrylic acid compounds having one or more (meth)acryloyl groups within the molecule, and vinyl compounds. The active energy ray curable component is preferably a polyfunctional (meth)acrylate having two or more (meth)acryloyl groups within the molecule.

[0095] The cured resin layer can function as a protective layer and an adhesive layer for linear polarizers and second protective films, or it can function as both a protective layer and an adhesive layer.

[0096] The thickness of the cured resin layer is suitable to be 0.1μm or more, but can be 0.5μm or more, 1.0μm or more, 1.5μm or more, or 2.0μm or more. Alternatively, it can be less than 10μm, less than 8μm, less than 7μm, less than 5μm, less than 4μm, or less than 3μm.

[0097] (N atoms in the second resin layer)

[0098] The second resin layer 140 is suitable to contain a compound containing nitrogen atoms. That is, for example, when the second resin layer is a curable resin layer, the active energy ray curable component (polymerizable compound) and / or photopolymerization initiator is suitable to contain nitrogen atoms. Compounds containing nitrogen atoms derived from photopolymerization initiators are particularly suitable.

[0099] The active energy-curing component containing nitrogen atoms refers to, for example, (meth)acrylic acid compounds containing nitrogen, such as N-substituted (meth)acrylamide. Among these, N,N-dimethylacrylamide and acryloylmorpholine are preferred.

[0100] Examples of photopolymerization initiators containing nitrogen atoms include tertiary amines, among which heterocyclic tertiary amines such as Omnirad 369 and Omnirad 907 (both manufactured by IGM Resin BV) are preferred.

[0101] The ratio R of the mass of N atoms in the thickness direction section of the second resin layer to the total mass of N and O atoms is suitable to be 1 to 10 mass. The lower limit of this ratio R can be 1.5 mass, 2 mass, or 3 mass, and the upper limit can be 8 mass or 5 mass.

[0102] In this specification, the mass ratio of N atoms to O atoms in the cross-section of the layer is obtained by EDX measurement. The method for EDX measurement is described in the examples below.

[0103] (The ratio R of the thickness of the second resin layer 140 to N atoms)

[0104] The product RT of the ratio R (mass%) of the mass of N atoms in the thickness direction section of the second resin layer 140 to the total mass of N atoms and O atoms and the thickness (μm) of the second resin layer 140 is suitable to be 3 to 50 (mass%·μm).

[0105] The product RT is expressed as the product of the percentage R (in mass %) and the thickness of the second resin layer (in μm). The product RT can be 3 (mass %·μm) or more, 4 (mass %·μm) or more, 5 (mass %·μm) or more, 6 (mass %·μm) or more, 40 (mass %·μm) or less, 30 (mass %·μm) or less, 20 (mass %·μm) or less, or 10 (mass %·μm) or less.

[0106] (First bonding layer 150)

[0107] The first bonding layer 150 is disposed between the polarizer 200 and the phase difference portion 300, bonding them together. Figure 1 In the embodiment shown, the first bonding layer 150 is in contact with the second resin layer 140. Additionally, in Figure 2 In the embodiment shown, the first bonding layer 150 is in contact with the second protective film 190. The first bonding layer 150 may be in contact with the first liquid crystal phase retardation layer 30, or it may be in contact with the alignment film if the first liquid crystal phase retardation layer 30 has an alignment film.

[0108] The material of the first bonding layer 150 can be an adhesive or a bonding agent, and materials mentioned in the second bonding layer 40 described later can be used appropriately. When using an adhesive, the thickness of the first bonding layer can be set to 2 μm or more and 20 μm or less; when using a bonding agent, the thickness of the first bonding layer can be set to 1 μm or more and 10 μm or less.

[0109] The first bonding layer 150 is suitable as a cured product of an active energy radiation-cured adhesive or binder, and is suitable as a cured product of an active energy radiation-cured adhesive.

[0110] (Phase difference 30°)

[0111] The phase difference section 300 has a first liquid crystal phase difference layer 30, a second bonding layer 40, and a second liquid crystal phase difference layer 50 sequentially from the polarizer side.

[0112] (First liquid crystal phase reversal layer 30 and second liquid crystal phase reversal layer 50)

[0113] The liquid crystal phase retardation layer is a cured layer of an oriented polymeric liquid crystal compound that exhibits a phase retardation.

[0114] The liquid crystal phase retardation layer is not limited as long as it exhibits a phase difference in any direction. It can be a phase retardation layer that generates an in-plane phase difference, such as a positive A-plate and a negative A-plate, or a phase retardation layer that generates a phase difference in the thickness direction, such as a positive C-plate and a negative C-plate. Furthermore, the positive A-plate and the negative A-plate can be λ / 4 plates or λ / 2 plates, respectively. Additionally, the liquid crystal phase retardation layer can be tilted or formed in a cholesteric orientation.

[0115] The first liquid crystal phase retardation layer 30 and the second liquid crystal phase retardation layer 50 can each be a single-layer liquid crystal phase retardation layer or a stack of multiple liquid crystal phase retardation layers.

[0116] The liquid crystal phase retardation layer can be either positive wavelength dispersion or reverse wavelength dispersion.

[0117] The phase difference portion 300, which is a stack of the first liquid crystal phase difference layer 30, the second bonding layer 40 and the second liquid crystal phase difference layer 50, is suitable to satisfy the following relationship (1) and (2).

[0118] 100nm≤Re(550)≤180nm (1)

[0119] Re(450) / Re(550)≤1.00 (2)

[0120] [In equations (1) and (2),]

[0121] Re(450) represents the in-plane phase difference in nm for light with a wavelength of 450 nm.

[0122] Re(550) represents the in-plane phase difference in nm for light with a wavelength of 550 nm.

[0123] The in-plane phase difference value of the aforementioned laminate (phase difference body) is measured using an in-plane phase difference measuring device such as the KOBRA-WR manufactured by Oji Measurement & Testing Co., Ltd., with a polarizing plate laminated on the laminate via an adhesive, and the laminate in the state of polarizing plate / adhesive / first liquid phase difference layer / first bonding layer / second liquid crystal phase difference layer. The polarizing plate and adhesive are those described later.

[0124] Liquid crystal phase retardation layers are typically formed by coating a liquid crystal phase retardation layer forming composition containing a polymeric liquid crystal compound onto an alignment film formed on a substrate, and then polymerizing and curing the polymeric liquid crystal compound in an aligned state.

[0125] The thickness of the liquid crystal phase retardation layer is typically less than 10 μm, preferably less than 5 μm, and more preferably more than 0.3 μm and less than 3 μm.

[0126] To achieve a high level of anti-reflection capability, the liquid crystal retardation layer preferably has a λ / 4 plate function (i.e., a π / 2 phase difference function) across the entire visible light region. Specifically, a reverse wavelength dispersive λ / 4 layer is preferred, or a combination of two or more retardation films with different orientations is also preferred. For example, a retardation film with a λ / 2 plate function (i.e., a π phase difference function) and a retardation film with a λ / 4 plate function (i.e., a π / 2 phase difference function) can be combined.

[0127] Furthermore, from the viewpoint of being able to compensate for the anti-reflective function in the tilt direction, it is preferable to include a layer (positive C-plate) that is anisotropic in the thickness direction. In addition, each liquid crystal phase difference layer can be tilted or formed in a cholesteric orientation.

[0128] (Combination of the first liquid crystal phase reversal layer and the second liquid crystal phase reversal layer)

[0129] The first liquid crystal phase reversal layer and the second liquid crystal phase reversal layer can be the same liquid crystal phase reversal layer or a combination of different types of liquid crystal phase reversal layers.

[0130] For example, one of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer can be an inverse wavelength dispersion λ / 4 plate, and the other of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer can be a positive C plate.

[0131] Alternatively, one of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer may be a positive wavelength dispersive λ / 2 plate, and the other of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer may be a positive wavelength dispersive λ / 4 plate.

[0132] The following describes a stack of a reverse wavelength dispersion λ / 4 plate, a positive wavelength dispersion λ / 4 plate, and a positive wavelength dispersion λ / 2 plate, as an example of a liquid crystal phase difference layer, and a positive C plate.

[0133] (Inverse wavelength dispersion λ / 4 plate (R))

[0134] For the inverse wavelength dispersion λ / 4 plate, if the in-plane phase difference of light with wavelength λnm in the entire visible light region is set as Re(λ), then it is preferable to satisfy the optical characteristics shown in the following equations (R1) and (R2), and preferably to satisfy the optical characteristics shown in the following equations (R1), (R2) and (R3).

[0135] 100nm<Re(550)<160nm…(R1)

[0136] (In the formula, Re(550) represents the in-plane phase difference (in-plane delay) for light with a wavelength of 550 nm.)

[0137] Re(450) / Re(550)≤1.0…(R2)

[0138] 1.00≤Re(650) / Re(550)…(R3)

[0139] (In the formula, Re(450) represents the in-plane phase difference (in nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference (in nm) for light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference (in nm) for light with a wavelength of 650 nm.)

[0140] If the Re(450) / Re(550) ratio of the liquid crystal retardation film exceeds 1.0, the light leakage on the short-wavelength side of the ellipsoidal polarizer equipped with the liquid crystal retardation film 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 0.92 or less, and particularly preferably 0.82 or more and 0.88 or less.

[0141] The value of “Re(450) / Re(550)” can be arbitrarily adjusted by adjusting the mixing ratio of the polymeric liquid crystal compound, the stacking angle of multiple optical anisotropic layers, and the phase difference.

[0142] The in-plane phase difference value of the retardation film can be adjusted by the thickness of the retardation film. 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)), Δn(λ) and the film thickness d can be adjusted. The thickness of the retardation film is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the retardation film can be measured by an interferometer, a laser microscope or a stylus-type film thickness gauge. It should be noted that Δn(λ) depends on the molecular structure of the polymeric liquid crystal compound described later.

[0143] Re(λ)=d×Δn(λ)…(4)

[0144] (In the formula, Re(λ) represents the in-plane phase difference (nm) at wavelength λnm, d represents the film thickness, and Δn(λ) represents the birefringence at wavelength λnm.)

[0145] Liquid crystal retardation films are typically formed by coating a liquid crystal retardation layer film forming composition onto an alignment film formed on a substrate, and then polymerizing the polymerizable liquid crystal compound contained in the liquid crystal retardation layer film composition in an aligned state. Furthermore, the retardation film forming composition may further include solvents, photopolymerization initiators, photosensitizers, polymerization inhibitors, leveling agents, and adhesion enhancers.

[0146] <Polymerizable liquid crystal compound for forming a reverse wavelength dispersive λ / 4 plate>

[0147] Polymerizable liquid crystal compounds refer to liquid crystal compounds having polymerizable groups, especially photopolymerizable groups. Conventionally known polymerizable liquid crystal compounds can be used as polymerizable liquid crystal compounds for forming a reverse wavelength dispersion λ / 4 plate. Photopolymerizable groups refer to groups capable of participating in polymerization reactions through reactive species generated by a photopolymerization initiator, such as active free radicals or acids. Examples of photopolymerizable groups include vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloxy, ethylene oxide, and oxetyl. Acryloyloxy, methacryloxy, ethoxy, and oxetyl are preferred, with acryloyloxy being more preferred. The liquid crystal can be thermotropic or lyotropic; thermotropic liquid crystals are preferred from the perspective of enabling dense film thickness control. Furthermore, the phase-ordered structure in the thermotropic liquid crystal can be nematic liquid crystal or smectic liquid crystal. Additionally, it can be rod-shaped or disk-shaped liquid crystal. Polymerizable liquid crystal compounds can be used alone or in combination of two or more.

[0148] From the viewpoint of exhibiting reverse wavelength dispersion, liquid crystals with a mesocrystalline structure in a T-shaped or H-shaped form that further exhibit birefringence in a direction perpendicular to the direction of 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, as a structure of T-shaped liquid crystals, for example, compounds shown in the following formula (I) can be cited.

[0149] [Chemical Formula 1]

[0150]

[0151] 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, these two or more aromatic groups can be bonded to each other via single bonds, -CO-O-, -O-, or other divalent bonding groups.

[0152] G 1 and G 2 Each of these groups independently represents 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 replaced 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.

[0153] L 1 L 2 B 1 and B 2 Each is an independent single bond or a divalent linker.

[0154] k and l each independently represent integers from 0 to 3, satisfying the relation 1 ≤ k + l. Here, in the case where 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.

[0155] E 1 and E 2 Each alkadiyl group independently represents a carbon group with 1 to 17 carbon atoms. Here, the hydrogen atoms in the alkadiyl group can be replaced by halogen atoms, and the -CH2- 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 the following groups represents a polymeric group or a hydrogen atom independently, with at least one being a polymeric group.

[0156] G 1 and G 2Each 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 methyl-substituted 1,4-phenylene diel, 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.

[0157] 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.

[0158] L 1 and L 2 Each is preferably a single bond, an alkylene group having 1 to 4 carbon atoms, and a -O-, -S-, or -R bond. a1 OR a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, -R a7 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 This indicates an alkyl group or hydrogen atom with 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 the following: 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-.

[0159] B 1 and B 2 Each is preferably a single bond, an alkylene group having 1 to 4 carbon atoms, and a -O-, -S-, or -R bond. 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 the following: 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-.

[0160] 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, it becomes a symmetrical structure, which is therefore preferred.

[0161] E 1 and E 2 Alkadiyl groups with 1 to 17 carbon atoms are preferred, and alkadiyl groups with 4 to 12 carbon atoms are more preferred.

[0162] As P 1 or P 2 Examples of polymerizable groups include epoxy, vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, ethylene oxide, and oxetyl. Acryloyloxy, methacryloyloxy, ethoxy, and oxetyl are preferred, and acryloyloxy is more preferred.

[0163] 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 even more preferred. Furthermore, when Ar contains a nitrogen atom, the nitrogen atom preferably has π electrons.

[0164] In formula (I), N represents 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.

[0165] As an aromatic group represented by Ar, the following groups can be suitably listed, for example.

[0166] [Chemical Formula 2]

[0167]

[0168] In equations (Ar-1) to (Ar-23), * indicates a connecting part, and Z 0 Z 1 and Z 2 Each can independently represent a hydrogen atom, a halogen atom, an alkyl group with 1 to 12 carbon atoms, a cyano group, a nitro group, an alkyl sulfinyl group with 1 to 12 carbon atoms, an alkyl sulfonyl group with 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group with 1 to 12 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, an alkyl thio group with 1 to 12 carbon atoms, an N-alkylamino group with 1 to 12 carbon atoms, an N,N-dialkylamino group with 2 to 12 carbon atoms, an N-alkylaminosulfonyl group with 1 to 12 carbon atoms, or an N,N-dialkylaminosulfonyl group with 2 to 12 carbon atoms.

[0169] 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 as an alkyl group having 1 to 4 hydrogen atoms or carbon atoms.

[0170] J1 and J 2 Each can be used to represent a carbon atom or a nitrogen atom independently.

[0171] Y 1 and Y 2 Each can be independently represented by an aromatic hydrocarbon group or an aromatic heterocyclic group that can be substituted.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] Z 0 Z 1 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 Further preferred are hydrogen atoms, alkyl groups having 1 to 12 carbon atoms, and cyano groups, Z. 1 and Z 2 Further preferred are hydrogen atoms, fluorine atoms, chlorine atoms, methyl groups, and cyano groups.

[0176] Q 1 and Q 2 Preferred NH-, S-, NR 2’ -、-O-,R 2’ Hydrogen atoms are preferred. Among them, -S-, -O-, and -NH- are particularly preferred.

[0177] From the perspective of molecular stability, formulas (Ar-6) and (Ar-7) are preferred among formulas (Ar-1) to (Ar-23).

[0178] In formula (Ar-16) ~ (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, as described previously, 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.

[0179] Among polymerizable liquid crystal compounds, those with a maximum absorption wavelength of 300–400 nm are preferred. When a photopolymerization initiator is included in the polymerizable liquid crystal composition, polymerization and gelation of the polymerizable liquid crystal compound may occur 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 photopolymerization initiator and the polymerization and gelation of the polymerizable liquid crystal compound caused by these reactive species can be effectively suppressed even when exposed to ultraviolet light during storage. Therefore, this is advantageous in terms of the long-term stability of the polymerizable liquid crystal composition, and can improve 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 measured using a UV-Vis spectrophotometer in a solvent. This solvent is one capable of dissolving the polymerizable liquid crystal compound, such as chloroform.

[0180] Relative to 100 parts by weight of the solid component of the polymeric liquid crystal composition, the content of the polymeric liquid crystal compound in the polymeric liquid crystal composition 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 solid component of the polymeric liquid crystal composition refers to all components after removing volatile components such as organic solvents from the polymeric liquid crystal composition.

[0181] [A laminate comprising a positive wavelength dispersive λ / 2 plate and a positive wavelength dispersive λ / 4 plate]

[0182] As one method to achieve anti-reflective properties, a laminate composed of a positive wavelength dispersive λ / 2 plate and a positive wavelength dispersive λ / 4 plate is known. For example, an illustrative laminate can be obtained by combining layers having the optical properties shown in Equations (Q1), (Q3), and (Q4) with layers having the optical properties shown in Equations (Q2), (Q3), and (Q4) in a specific slow-axis relationship.

[0183] 100nm<Re(550)<160nm (Q1)

[0184] 200nm<Re(550)<320nm (Q2)

[0185] Re(450) / Re(550)≥1.00(Q3)

[0186] 1.00≥Re(650) / Re(550) (Q4)

[0187] Examples of methods for combining the above-mentioned components include those disclosed in Japanese Patent Application Publication No. 2015-163935 and WO2013 / 137464. From the viewpoint of perspective compensation, it is preferable to use a λ / 2 layer of polymer containing a disc-shaped polymeric liquid crystal compound and a λ / 4 layer of polymer containing a rod-shaped polymeric liquid crystal compound.

[0188] Examples of disc-shaped polymeric liquid crystal compounds include compounds containing groups represented by formula (W) (hereinafter sometimes referred to as polymeric liquid crystal compounds (C)).

[0189] [Chemical Formula 3]

[0190]

[0191] In formula (W), R 40 Represent the following formulas (W-1) to (W-5).

[0192] [Chemical Formula 4]

[0193]

[0194] X 40 and Z 40 This refers to an alkyldiyl group with 1 to 12 carbon atoms, where the hydrogen atoms can be replaced by an alkoxy group with 1 to 5 carbon atoms, and the hydrogen atoms in the alkoxy group can be replaced by halogen atoms. Furthermore, the -CH2- group constituting this alkyldiyl group can be replaced by -O- or -CO-. Additionally, m2 is an integer from 1 to 20.

[0195] Examples of rod-shaped polymeric liquid crystal compounds include those represented by formulas (I), (II), (III), (IV), (V), or (VI).

[0196] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I)

[0197] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II)

[0198] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III)

[0199] P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV)

[0200] P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V)

[0201] P11-B11-E11-B12-A11-B13-A12-F11 (VI)

[0202] A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atoms contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be replaced by halogen atoms, alkyl groups with 1 to 6 carbon atoms, alkoxy groups with 1 to 6 carbon atoms, cyano groups or nitro groups, and the hydrogen atoms contained in the alkyl groups with 1 to 6 carbon atoms and the alkoxy groups with 1 to 6 carbon atoms may be replaced by fluorine atoms.

[0203] B11 represents -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -, -NR 16 -CO-, -CO-, -CS-, or a single bond. R 16 It represents an alkyl group having 1 to 6 hydrogen atoms or carbon atoms.

[0204] B12 and B13 independently represent -C≡C-, -CH=CH-, -CH2-CH2-, -O-, -S-, -C(=O)-, -C(=O)-O-, -O-C(=O)-, -O-C(=O)-O-, -CH=N-, -N=CH-, -N=N-, -C(=O)-NR 16 -, -NR 16-C(=O)-, -OCH2-, -OCF2-, -CH2O-, -CF2O-, -CH=CH-C(=O)-O-, -O-C(=O)-CH=CH- or single bond.

[0205] E11 represents an alkyldiyl group with 1 to 12 carbon atoms. The hydrogen atoms in this alkyldiyl group can be replaced by alkoxy groups with 1 to 5 carbon atoms, and the hydrogen atoms in these alkoxy groups can be replaced by halogen atoms. Furthermore, the -CH2- group constituting this alkyldiyl group can be replaced by -O- or -CO-.

[0206] The number of carbon atoms in the aromatic hydrocarbon group and alicyclic hydrocarbon group of A11 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, and particularly preferably 5 or 6. As A11, cyclohexane-1,4-diyl or 1,4-phenylene are preferred.

[0207] As E11, a linear alkyldiyl group with 1 to 12 carbon atoms is preferred. The -CH2- group constituting this alkyldiyl group can be replaced by -O-.

[0208] Specifically, examples include straight-chain alkyl diyl groups with 1 to 12 carbon atoms, such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; and -CH2-CH2-O-CH2-CH2-, -CH2-CH2-O-CH2-CH2-O-CH2-CH2-, and -CH2-CH2-O-CH2-CH2-O-CH2-CH2-.

[0209] As B11, -O-, -S-, -CO-O-, and -O-CO- are preferred, with -CO-O- being more preferred.

[0210] B12 and B13 are each preferably -O-, -S-, -C(=O)-, -C(=O)-O-, -O-C(=O)-, -O-C(=O)-O-, and more preferably -O- or -O-C(=O)-O-.

[0211] As the polymerizable group shown in P11, from the perspective of high polymerization reactivity, especially photopolymerization reactivity, free radical polymerizable groups or cationic polymerizable groups are preferred. From the perspective of ease of operation and ease of manufacturing the liquid crystal compound itself, the polymerizable group is preferably the group shown in the following formulas (P-11) to (P-15).

[0212] [Chemical Formula 5]

[0213]

[0214] In equations (P-11) to (P-15), R 17 ~R 21 Each can independently represent an alkyl group or a hydrogen atom having 1 to 6 carbon atoms.

[0215] As specific examples of the groups shown in formulas (P-11) to (P-15), the groups shown in formulas (P-16) to (P-20) can be cited below.

[0216] [Chemical Formula 6]

[0217]

[0218] P11 is preferably a group represented by formula (P-14) to (P-20), more preferably vinyl, p-zirconia, epoxy or oxetyl.

[0219] The group shown in P11-B11- is further preferably acryloyloxy or methacryloyloxy.

[0220] (In the formula, A12 to A14 are each independently equivalent to A11, B14 to B16 are each independently equivalent to B12, B17 is equivalent to B11, and E12 is equivalent to E11. F11 represents a hydrogen atom, an alkyl group with 1 to 13 carbon atoms, an alkoxy group with 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 with 1 to 10 carbon atoms, or a halogen atom. The -CH2- group constituting the alkyl and alkoxy groups can be replaced by -O-.)

[0221] [Other components]

[0222] In addition to the configuration of combining the above-mentioned positive wavelength dispersive λ / 2 layer and positive wavelength dispersive λ / 4 layer, the first liquid crystal retardation layer and the second liquid crystal retardation layer can also be a stack formed by tilting and cholesteric orientation of at least one liquid crystal retardation layer. Examples of known configurations include those disclosed in Publications No. WO2021 / 060378, WO2021 / 132616, and WO2021 / 132624.

[0223] [Composition for forming liquid crystal phase retardation layer]

[0224] Relative to 100 parts by mass of the solid component of the liquid crystal phase retardation layer formation composition, the content of the polymerizable liquid crystal compound in the liquid crystal phase retardation layer formation composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the orientation of the obtained liquid crystal phase retardation layer. It should be noted that, in this specification, the solid component of the liquid crystal phase retardation layer formation composition refers to all components after removing volatile components such as organic solvents from the liquid crystal phase retardation layer formation composition.

[0225] <Positive C Board>

[0226] There are no particular limitations as long as the positive C plate is anisotropic in the thickness direction. Without tilting or cholesteric orientation, it has the optical properties shown in formula (PC3).

[0227] nx≈ny<nz (PC3)

[0228] The in-plane phase difference Re(550) at a wavelength of 550 nm for the positive C-plate is typically in the range of 0–10 nm, preferably in the range of 0–5 nm. Furthermore, the phase difference Rth(550) in the thickness direction at a wavelength of 550 nm is typically in the range of -170 nm to -10 nm, preferably -150 nm to -20 nm, and more preferably -100 nm to -40 nm. If the phase difference in the thickness direction is within this range, the anti-reflective properties in the tilt direction can be further improved.

[0229] The thickness of the positive C plate is typically less than 10 μm, preferably less than 5 μm, and more preferably more than 0.3 μm and less than 3 μm.

[0230] 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.

[0231] Examples of rod-shaped polymeric liquid crystals include compounds represented by formulas (I), (II), (III), (IV), (V), or (VI).

[0232] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I)

[0233] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II)

[0234] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III)

[0235] P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV)

[0236] P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V)

[0237] P11-B11-E11-B12-A11-B13-A12-F11 (VI)

[0238] (In the formula, A12 to A14 are each independently equivalent to A11, B14 to B16 are each independently equivalent to B12, B17 is equivalent to B11, and E12 is equivalent to E11. F11 represents a hydrogen atom, an alkyl group with 1 to 13 carbon atoms, an alkoxy group with 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 with 1 to 10 carbon atoms, or a halogen atom. The -CH2- group constituting the alkyl and alkoxy groups can be replaced by -O-.)

[0239] Relative to 100 parts by mass of the solid component of the liquid crystal phase retardation layer formation composition, the content of the polymeric liquid crystal compound in the liquid crystal phase retardation layer formation composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more 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 obtained liquid crystal phase retardation layer. It should be noted that, in this specification, the solid component of the liquid crystal phase retardation layer formation composition refers to all components after removing volatile components such as organic solvents from the polymeric liquid crystal composition.

[0240] <Composition for forming liquid crystal phase retardation layer>

[0241] Liquid crystal phase retardation layers are typically formed by coating a liquid crystal phase retardation layer forming composition containing a polymerizable liquid crystal compound onto an alignment film to be formed as needed on a substrate, thereby polymerizing and curing the polymerizable liquid crystal compound in an aligned state.

[0242] In addition to the polymerizable liquid crystal compound described above, the composition for forming a liquid crystal phase retardation layer may further include reactive additives such as solvents, leveling agents, polymerization initiators, photosensitizers, polymerization inhibitors, crosslinking agents, and binding agents. From a processability point of view, it is preferable to include solvents and / or leveling agents. From the point of view of adding Si, it is suitable to add silicone-based leveling agents.

[0243] <Solvent>

[0244] The composition for forming a liquid crystal phase retardation layer may contain a solvent. Generally, polymerizable liquid crystal compounds have high viscosity; therefore, by preparing a composition for forming a liquid crystal phase retardation layer that is dissolved in a solvent, coating becomes easier, resulting in easier formation of the liquid crystal phase retardation layer. As a solvent, a solvent capable of completely dissolving the polymerizable liquid crystal compound is preferred; furthermore, a solvent that is inactive in the polymerization reaction of the polymerizable liquid crystal compound is preferred.

[0245] Examples of solvents include: alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; and amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolinone. These solvents can be used alone or in combination of two or more.

[0246] The solvent content is preferably 50 to 98% by mass relative to the total amount of the liquid crystal phase retardation layer forming composition. In other words, the solid content in the liquid crystal phase retardation layer forming composition is preferably 2 to 50% by mass, more preferably 5 to 30% by mass. If the solid content is 50% by mass or less, the viscosity of the liquid crystal phase retardation layer forming composition becomes lower, and therefore the thickness of the liquid crystal phase retardation layer becomes approximately uniform, thus reducing the tendency for unevenness to occur in the liquid crystal phase retardation layer. Furthermore, the content of this solid content can be determined with consideration of the desired thickness of the optical anisotropy layer.

[0247] Leveling agent

[0248] The composition for forming a liquid crystal phase retardation layer may contain a leveling agent. A leveling agent is an additive that functions to adjust the flowability of the composition and make the film obtained by coating the composition flatter; examples include silicone-based leveling agents, acrylic-based leveling agents, and fluorinated leveling agents. Among these, silicone-based and fluorinated leveling agents, which have excellent functions in reducing the surface tension of the film obtained by coating the composition, are preferred.

[0249] Examples of silicone-based leveling agents include leveling agents with a polyorganosiloxane backbone.

[0250] Examples of groups that bond to silicon atoms (silicon atoms forming siloxane bonds) in polyorganosiloxanes include hydrocarbon groups. Organosilicon leveling agents can be leveling agents with two hydrocarbon groups bonded to silicon atoms.

[0251] There are no limitations on the groups that bond with silicon atoms, but alkyl or aryl groups with 1 to 10 carbon atoms are preferred, methyl or phenyl groups are more preferred, and methyl groups are even more preferred.

[0252] The groups that bond with silicon atoms can be only one type or more than two types.

[0253] In addition, the number of repeats (degree of polymerization) of the siloxane unit is not particularly limited, but is preferably 2 to 10,000, more preferably 3 to 5,000, and even more preferably 5 to 1,000.

[0254] Silicone-based leveling agents can be commercially available, such as SH710 (manufactured by Toray Dow Corning Co., Ltd.), BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-370, BYK-377, BYK-378, BYK-3455, BYK... BYK-Chemie Japan Co., Ltd., KF-945, KF-6015, KF-6020 (manufactured by Shin-Etsu Chemical Co., Ltd.), TEGORad2300, TEGORad2200N, and TEGORad2011 (manufactured by Degussa) are commercially available products containing free radical polymerizable groups such as (meth)acryloyl groups added to the polyether chain. Examples include BYK-UV3500, BYK-UV3505, BYK-3510, BYK-UV3530, BYK-UV3570, BYK-UV3575, and BYK-UV3576 (manufactured by BYK-Chemie Japan Co., Ltd.). (Made by Japan Co., Ltd.), KP-422, KP-416, KP-418, KP-410, KP-411, KP-412, KP-413, KP-423, KP-414, KP-415, KP-420, KP-983 (the above are manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0255] Relative to 100 parts by mass of the polymerizable liquid crystal compound, the content of the organosilicon leveling agent in the liquid crystal phase difference layer forming composition is preferably 0.001 parts by mass to 2 parts by mass, more preferably 0.01 parts by mass to 1.5 parts by mass, and even more preferably 0.1 parts by mass to 1.5 parts by mass.

[0256] As a fluorinated leveling agent, there are no particular limitations; examples include leveling agents with a fluorinated aliphatic hydrocarbon skeleton.

[0257] The skeleton of the aforementioned fluoroaliphatic hydrocarbons is not particularly limited, and examples include fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluorotert-butane, fluoropentane, fluorohexane, and other fluoroalkanes with 1 to 10 carbon atoms.

[0258] A fluorinated aliphatic hydrocarbon skeleton can be formed by replacing at least some of the hydrogen atoms with fluorine atoms, or it can be a perfluorinated aliphatic hydrocarbon skeleton in which all hydrogen atoms are replaced by fluorine atoms.

[0259] In addition, the aforementioned fluoroaliphatic hydrocarbon skeleton can form a polyfluoroalkylene ether skeleton as a repeating unit via ether bonds.

[0260] There are no particular limitations on the fluorinated aliphatic hydrocarbon group that serves as the repeating unit; examples include fluorinated C1-4 alkylene groups such as fluorinated methylene, fluorinated ethylene, fluorinated propylene, and fluorinated isopropylene.

[0261] The aforementioned fluorinated aliphatic hydrocarbon groups can be only one type or two or more types.

[0262] The number of repeats (degree of polymerization) of the fluoroalkylene ether unit is not particularly limited, but is preferably 10 to 10,000, more preferably 30 to 5,000, and even more preferably 50 to 1,000.

[0263] Examples of fluorinated leveling agents include commercially available products such as MEGAFACE (registered trademark) R-08, MEGAFACE R-30, MEGAFACE R-90, MEGAFACE F-410, MEGAFACE F-411, MEGAFACE F-443, MEGAFACE F-445, MEGAFACE F-470, MEGAFACE F-471, MEGAFACE F-477, MEGAFACE F-479, MEGAFACE F-482, MEGAFACE F-483, MEGAFACE F-281, MEGAFACE F-253, MEGAFACE F-251, MEGAFACE F-114, MEGAFACE F-510, MEGAFACE F-551, MEGAFACE F-552, MEGAFACE F-553, MEGAFACE F-554, etc. MEGAFACE MEGAFACE RS-75, MEGAFACE RS-76-E, MEGAFACE RS-76-NS, MEGAFACE RS-78, MEGAFACE RS-90, MEGAFACE DS-21 (DIC Corporation); Surflon (registered trademark) S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-105, KH-40 and SA-100 (AGC SEIMI CHEMICAL Corporation); E1830, E5844 (Daikin Fine Chemicals Research Institute, Ltd.);EFTOP EF301, EFTOP EF303, EFTOP EF351 and EFTOP EF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.). ;

[0264] Relative to 100 parts by mass of the polymerizable liquid crystal compound, the content of the fluorine-based leveling agent in the liquid crystal phase difference layer forming composition is preferably 0.001 parts by mass to 2 parts by mass, more preferably 0.01 parts by mass to 1.5 parts by mass, and even more preferably 0.1 parts by mass to 1.5 parts by mass.

[0265] When the composition for forming a liquid crystal phase retardation layer contains various leveling agents, the amount is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. It should be noted that the composition for forming an optical anisotropic layer may contain two or more leveling agents.

[0266] <Polymerization Initiator>

[0267] The composition for forming a liquid crystal phase retardation layer may contain a polymerization initiator. A polymerization initiator is a compound capable of initiating a polymerization reaction of polymerizable liquid crystal compounds, etc. From the viewpoint of not depending on the phase state of the thermotropic liquid crystal, a photopolymerization initiator that generates active free radicals through the action of light is preferred as the polymerization initiator.

[0268] Any known photopolymerization initiator can be used, as long as it is a compound capable of initiating the polymerization reaction of a polymerizable liquid crystal compound. Specifically, photopolymerization initiators capable of generating active free radicals or acids through the action of light are examples, with photopolymerization initiators that generate free radicals through the action of light being preferred. Photopolymerization initiators can be used alone or in combination of two or more.

[0269] As photopolymerization initiators, known photopolymerization initiators can be used. For example, as photopolymerization initiators that generate active free radicals, self-cracking benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, azo compounds, etc., can be used. Hydrogen-abstracting compounds such as benzophenone compounds, alkylacetophenone compounds, benzoin ether compounds, benzoin ketal compounds, dibenzocycloheptenone compounds, anthraquinone compounds, xanthonesone compounds, thioxanthonesone compounds, haloacetophenone compounds, diekoxyacetophenone compounds, halodiimidazole compounds, halotriazine compounds, triazine compounds, etc., can be used. As photopolymerization initiators that generate acids, iodonium salts and sulfonium salts, etc., can be used. From the perspective of excellent reaction efficiency at low temperatures, self-destructive photopolymerization initiators are preferred, especially acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds.

[0270] The content of the polymerization initiator in the composition for forming the liquid crystal phase retardation layer can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound. It is typically 0.1 to 30 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass. If the content of the polymerization initiator is within the above range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal compound.

[0271] <Sensitizer>

[0272] The composition for forming a liquid crystal phase retardation layer may contain a sensitizer. A photosensitizer is preferred as the sensitizer. Examples of such sensitizers include: xanthonesone compounds such as xanthonesone and thioxanthonesone (e.g., 2,4-diethylthioxanthonesone, 2-isopropylthioxanthonesone); anthracene compounds such as anthracene and alkoxy-containing anthracene (e.g., dibutoxyanthracene); phenothiazine and rubrene.

[0273] When the composition for forming the liquid crystal phase retardation layer contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition can be further promoted. The amount of the sensitizer used is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass.

[0274] <Antioxidants>

[0275] From the viewpoint of stabilizing the polymerization reaction, compositions for forming liquid crystal phase retardation layers may contain antioxidants. Antioxidants allow for control over the extent of polymerization of the polymerizable liquid crystal compound.

[0276] The antioxidants mentioned above can be, for example, primary antioxidants selected from phenolic antioxidants, amine antioxidants, quinone antioxidants, and nitroso antioxidants, or secondary antioxidants selected from phosphorus antioxidants and sulfur antioxidants.

[0277] When the composition for forming the liquid crystal phase retardation layer contains an antioxidant, the antioxidant content is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. The antioxidant can be used alone or in combination of two or more types. If the antioxidant content is within the above range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal compound.

[0278] <Reactive Additives>

[0279] The composition for forming a liquid crystal phase retardation layer may include a reactive additive. Preferably, the reactive additive has a carbon-carbon unsaturated bond, an active hydrogen reactive group, or a thiol group within its molecule. It should be noted that the "active hydrogen reactive group" referred to here means a group reactive to groups with active hydrogen, such as carboxyl (-COOH), hydroxyl (-OH), and amino (-NH2). Glycidyl, oxazoline, carbodiimide, aziridinyl, imide, isocyanate, thioisocyanate, and maleic anhydride groups are representative examples. The number of reactive groups in the reactive additive is typically 1 to 20, preferably 1 to 10.

[0280] (Orientation film)

[0281] An alignment film can be disposed on one side of the first liquid crystal phase retardation layer 30. Alternatively, an alignment film can be disposed on one side of the second liquid crystal phase retardation layer 50.

[0282] [First orientation film and second orientation film]

[0283] In this specification, the alignment film has an alignment limiting force that causes the polymerizable liquid crystal compound to be aligned in a desired direction.

[0284] Alignment films facilitate the alignment of polymeric liquid crystal compounds. The states of liquid crystal alignment, such as horizontal alignment, vertical alignment, mixed alignment, and tilted alignment, vary depending on the properties of the alignment film and the polymeric liquid crystal compound, and their combinations can be arbitrarily chosen. For example, if the alignment film is a material exhibiting horizontal alignment as an alignment constraint force, the polymeric liquid crystal compound can form a horizontal or mixed alignment; if it is a material exhibiting vertical alignment, the polymeric liquid crystal compound can form a vertical or tilted alignment. The terms "horizontal," "vertical," etc., refer to the direction of the optical axis of the aligned polymeric liquid crystal compound relative to the plane of the optical anisotropy layer. For example, vertical alignment means that the optical axis of the aligned polymeric liquid crystal compound is in a direction perpendicular to the plane of the optical anisotropy layer. Here, "vertical" means 90° ± 20° relative to the plane of the optical anisotropy layer.

[0285] Regarding the orientation constraint force, when the orientation film is formed from an orientation polymer, it can be arbitrarily adjusted according to the surface condition and friction conditions; when it is formed from a photo-oriented polymer, it can be arbitrarily adjusted according to 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.

[0286] As an alignment film formed between a substrate and an optically anisotropic layer, an alignment film that is insoluble in the solvent used to form the optically anisotropic layer on the alignment film and has heat resistance in the heat treatment for solvent removal and liquid crystal alignment is preferred. Examples of alignment films include alignment films containing an alignment polymer, photoalignment films, groove alignment films, and stretch films stretched along the alignment direction. In the case of application to long, roll-shaped films, photoalignment films are preferred from the viewpoint that the alignment direction can be easily controlled.

[0287] 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.

[0288] Examples of orientation polymers used in friction-oriented films include polyamides and gelatin-like polymers with intramolecular amide bonds, polyimides and their hydrolysates (i.e., polyamic acid) with intramolecular imide bonds, 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.

[0289] One method for performing friction is to bring a film of an oriented polymer, formed on the surface of a substrate by coating an oriented polymer composition onto a substrate and annealing it, into contact with a friction roller wound with a friction cloth and rotating.

[0290] Photoalignment films contain polymers, oligomers, or monomers having photoreactive groups. The photoalignment film acquires orientation confinement force by irradiating polarized light. From the viewpoint that the direction of the orientation confinement force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light, photoalignment films are more preferred.

[0291] A photoreactive group is a group that generates liquid crystal alignment capability through light irradiation. Specifically, it is a group that undergoes a photoreaction, such as orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction, which is the origin of liquid crystal alignment capability. Among these photoreactive groups, groups that undergo dimerization or photocrosslinking reactions are preferred from the perspective of excellent alignment. As a photoreactive group capable of undergoing such reactions, a photoreactive group having unsaturated bonds, especially double bonds, is preferred, and a group having at least one selected from carbon-carbon double bonds (C=C bond), carbon-nitrogen double bonds (C=N bond), nitrogen-nitrogen double bonds (N=N bond), and carbon-oxygen double bonds (C=O bond) is more preferred.

[0292] Examples of photoreactive groups with C=C bonds include vinyl, polyenyl, linyl, linazolyl, linazoliumyl, chalcone, and cinnamoyl groups. Chalcone and cinnamoyl groups are preferred from the viewpoint of easy control of reactivity and the expression of 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.

[0293] When irradiating with polarized light, the polarized light can be irradiated directly from the film surface or from the substrate side and transmitted through the polarized light. Furthermore, the polarized light is particularly preferably substantially parallel. Regarding the wavelength of the irradiated polarized light, it is preferable to use polarized light in the wavelength range where the photoreactive groups of the polymer or monomer containing 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 used 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 of the high luminous intensity of ultraviolet light at a wavelength of 313 nm. The light from the above-mentioned light source is irradiated by passing it through a suitable polarizer, thereby irradiating with polarized light. As the polarizer, polarizing filters, Glan-Thomson prisms, Glan-Taylor prisms, and wire-grid polarizers can be used.

[0294] The composition for forming the alignment film may contain a leveling agent as needed. Particularly when the outer adhesive layer 400 in the optical laminate 10 contains a silane compound, the composition for forming the alignment film bonded to the outer adhesive layer 400 preferably contains a leveling agent. As the leveling agent, silicone-based and / or fluorine-based leveling agents described later in the section on liquid crystal phase retardation layers can be used, with silicone-based leveling agents being preferred. The leveling agent typically contains 0.001 to 3% by mass in the solid components of the composition for forming the alignment film at a rate preferably 0.001 to 3% by mass, more preferably 0.01 to 3% by mass, and even more preferably 0.1 to 3% by mass.

[0295] (Second bonding layer 40)

[0296] The second bonding layer 40 bonds the liquid crystal phase difference layers together. The second bonding layer 40 can be an adhesive layer (also known as a pressure-sensitive adhesive) or an adhesive layer.

[0297] (Adhesive layer)

[0298] 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 based on 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 based on acrylic resins with excellent transparency, adhesion, re-peelability, weather resistance, and heat resistance are particularly suitable.

[0299] The adhesive composition may further include crosslinking agents, silane compounds, antistatic agents, etc.

[0300] [(Meth)acrylic resins]

[0301] The (meth)acrylate resin contained in the adhesive composition is preferably a polymer (hereinafter also referred to as "(meth)acrylate polymer") with structural units derived from alkyl methacrylates of the following formula (I) as the main component (e.g., containing 50 parts by mass or more relative to 100 parts by mass of the structural units of the (meth)acrylate resin).

[0302] It should be noted that in this specification, (meth)acrylic resin refers to either acrylic resin or methacrylic resin, and the "(meth)" in (meth)acrylate, etc., has the same meaning.

[0303] [Chemical Formula 7]

[0304]

[0305] [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 structure, including straight-chain, branched, or cyclic forms. The hydrogen atoms of this alkyl group can be substituted with alkoxy groups having 1 to 10 carbon atoms.

[0306] Examples of (meth)acrylates represented by formula (I) include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, isohexyl methacrylate, n-heptyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, n-nonyl methacrylate, isononyl methacrylate, n-decyl methacrylate, isodecyl methacrylate, n-dodecyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, stearyl methacrylate, tert-butyl methacrylate, etc. Specific examples of alkyl acrylates containing alkoxy groups include 2-methoxyethyl methacrylate and ethoxymethyl methacrylate. Preferably, it contains n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate, and particularly preferably contains n-butyl (meth)acrylate.

[0307] (Meth)acrylate polymers may contain structural units derived from other monomers besides 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.

[0308] 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.

[0309] Relative to all 100 parts by mass of the (meth)acrylate polymer, 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.

[0310] Examples of monomers containing aromatic groups include (meth)acrylates having one (meth)acryloyl group and one or more aromatic rings (e.g., benzene ring, naphthalene ring, etc.) within the molecule, and having phenyl, phenoxyethyl, or benzyl groups. By incorporating these structural units, the whitening phenomenon of polarizers occurring under high temperature and high humidity environments can be suppressed.

[0311] Relative to all 100 parts by mass of the (meth)acrylate polymer, 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.

[0312] 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.

[0313] In addition, structural units derived from other monomers besides structural unit (I) may also 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.

[0314] The weight-average molecular weight (hereinafter, also referred to as "Mw") of the (meth)acrylic resin (1) is preferably between 500,000 and 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 operability of applying 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. In this specification, "weight-average molecular weight" and "number-average molecular weight" are polystyrene conversion values ​​determined by gel permeation chromatography (GPC).

[0315] When a (meth)acrylic resin is dissolved in ethyl acetate to prepare a 20% by mass solution, its 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 polarizing plate containing the adhesive layer formed using the above resin. The above viscosity can be measured using a Brookfield viscometer.

[0316] 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).

[0317] (Meth)acrylic resins may contain two or more (meth)acrylate polymers. Examples of such (meth)acrylate polymers include (meth)acrylate polymers with relatively low molecular weights, such as (meth)acrylate polymers with structural units (I) derived from the above-mentioned (meth)acrylates as the main component and a weight-average molecular weight in the range of 50,000 to 300,000.

[0318] (Meth)acrylic resins are typically 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 by polymerization using active energy rays such as ultraviolet light.

[0319] [Cross-linking agent]

[0320] 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 pot life of the adhesive composition, the crosslinking rate and the durability of the polarizer.

[0321] 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.

[0322] The proportion of crosslinking agent relative to 100 parts by weight of (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.

[0323] [Silane compounds]

[0324] The adhesive composition may also contain silane compounds.

[0325] 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.

[0326] In addition, silane compounds may include oligomers derived from the aforementioned silane compounds.

[0327] The content of silane compound 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 compound is 0.01 parts by weight or more, there is a tendency for improved adhesion between the adhesive layer and the adherend; if the content is 10 parts by weight or less, there is a tendency for suppression of silane compound exudation from the adhesive layer. As the silane compound, a silane coupling agent is suitable, and known silane coupling agents can be used.

[0328] <Antistatic Agent>

[0329] The adhesive composition may further include an antistatic agent. Known antistatic agents are examples, and ionic antistatic agents are suitable. As the cationic component constituting the ionic antistatic agent, organic and inorganic cations are examples. As organic cations, pyridinium cations, imidazolium cations, ammonium cations, sulfonium cations, phosphonium cations, etc., are examples. 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., are examples. As the anionic component constituting the ionic antistatic agent, it can be any of inorganic and organic anions; from the perspective of superior antistatic performance, anionic components containing fluorine atoms are preferred. As an anionic component containing fluorine atoms, hexafluorophosphate anion (PF6) is an example. - ), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - ], bis(fluorosulfonyl)imide anion [(FSO2)2N - Anions, etc.

[0330] From the perspective of excellent antistatic properties and long-term stability of the adhesive composition, ionic antistatic agents that are solid at room temperature are preferred.

[0331] The content of antistatic agent relative to 100 parts by weight of (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.

[0332] The adhesive composition may contain, alone or in combination with two or more additives such as UV absorbers, solvents, crosslinking catalysts, tackifying resins (tackifiers), and plasticizers. Additionally, it is also useful to incorporate UV-curable compounds into the adhesive composition, forming an adhesive layer which is then cured by UV irradiation to produce a harder adhesive layer.

[0333] 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, and then applying it to the surface of the layer to which the adhesive layer is to be formed and allowing it to dry.

[0334] The thickness of the adhesive layer is typically 0.1–30 μm, preferably 3–30 μm, and more preferably 5–25 μm.

[0335] (Adhesive layer)

[0336] The adhesive layer can be formed from an adhesive composition.

[0337] Examples of adhesive compositions include, for example, water-based 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 water-based adhesive compositions include compositions formed by dissolving a polyvinyl alcohol-based resin or urethane resin as a main component in water, and compositions formed by dispersing a polyvinyl alcohol-based resin or urethane resin as a main component in water. Water-based adhesive compositions may further contain curing components such as polyaldehydes, melamine compounds, zirconium oxide compounds, zinc compounds, glyoxal compounds, water-soluble epoxy resins, and crosslinking agents. Examples of water-based adhesive compositions include, for example, the adhesive compositions 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.

[0338] 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.

[0339] Cationic polymerizable compounds are compounds or oligomers that are solidified by cationic polymerization reactions through 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.

[0340] 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).

[0341] Examples of oxetane compounds include 3-ethyl-3-{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane, which contains one or more oxetane rings within its molecule.

[0342] 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 benzenediazonium hexafluoroantimonate; 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.

[0343] 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.

[0344] Free radical polymerizable compounds are compounds or oligomers that are solidified through free radical polymerization reactions caused by irradiation or heating with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Specifically, compounds with olefinic unsaturated bonds can be cited as examples. 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.

[0345] Examples of (meth)acrylic acid compounds include: (meth)acrylic acid oligomers having at least two (meth)acryloyl groups, obtained by reacting (meth)acrylic ester monomers, (meth)acrylamide monomers, and functional group-containing compounds in two or more reactions. In this specification, (meth)acryloyl group refers to either an acryloyl group or a methacryloyl group.

[0346] 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 photofree 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, fluorenone, etc. 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.

[0347] 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.

[0348] Active energy ray curable adhesive compositions may contain additives such as ion traps, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow modifiers, plasticizers, defoamers, antistatic agents, leveling agents, and solvents, as needed.

[0349] The adhesive composition and adhesive layer are suitable for containing a silicone-based or fluorine-based leveling agent as described in the section on liquid crystal phase retardation layers. 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 content, more preferably 0.01 to 1.5 parts by weight, and even more preferably 0.1 to 1.5 parts by weight.

[0350] The bonding of the first liquid crystal phase reversal layer and the second liquid crystal phase reversal layer using an adhesive layer can be performed as follows: an adhesive composition is applied to at least one bonding surface selected from the bonding surface of the first liquid crystal phase reversal layer and the bonding surface of the second liquid crystal phase reversal layer; the two layers are overlapped by the adhesive composition coating layer; they are bonded by pressing from above and below using a bonding roller or the like; the adhesive layer is dried; it is cured by irradiation with active energy rays or by heating.

[0351] Before forming the adhesive layer, at least one bonding surface selected from the bonding surface of the first liquid crystal phase reversal layer and the bonding surface of the second liquid crystal phase reversal layer may be subjected to easy bonding treatments such as saponification, corona treatment, plasma treatment, primer treatment, and anchor coating treatment.

[0352] The coating layer of the adhesive composition can be formed using various coating methods such as die coating machine, comma coating machine, gravure coating machine, bar coating machine, and doctor blade coating machine.

[0353] The light intensity during irradiation with active energy rays is determined based on the composition of the active energy ray-cured adhesive composition and is not particularly limited, but is preferably 10 mW / cm². 2 Above and 1,000 mW / 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. Irradiation at this intensity once or multiple times is performed, preferably with a cumulative light dose of 10 mJ / cm². 2 The above is more preferably set at 100 mJ / cm. 2 Above and 1,000 mJ / cm2 the following.

[0354] 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, chemical lamps, black lamps, microwave-excited mercury lamps, and metal halide lamps.

[0355] The thickness of the adhesive layer formed by the aqueous adhesive composition can be, for example, 5 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less, and can be 0.01 μm or more, preferably 0.05 μm or more.

[0356] 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, or 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more.

[0357] (Outer adhesive layer 400)

[0358] like Figure 1 As shown, the optical laminate 10 may have an outer adhesive layer 400 on the side opposite to the first bonding layer 150 relative to the phase difference portion 300.

[0359] The material and thickness of the outer adhesive layer 400 are not particularly limited; for example, the materials and thicknesses mentioned in the second bonding layer can be used appropriately. The thickness of the outer adhesive layer can be set to 1 μm or more and 100 μm or less, and is preferably 5 μm or more and 50 μm or less.

[0360] (Deformation method)

[0361] The present invention is not limited to the above-described embodiments and can have various modifications.

[0362] The phase difference section 300 may have only one liquid phase difference layer.

[0363] (Mechanism of action)

[0364] According to this embodiment, the polarizing plate 200 includes, from the side opposite to the phase difference portion 300, a first protective film 180, a linear polarizer 220, a first resin layer 130 and a second protective film 190 in sequence, and also includes a second resin layer 140 disposed between the first resin layer 130 and the first adhesive layer 150.

[0365] Such optical laminates can suppress the increase in thickness of linear polarizers in humid and hot environments.

[0366] The reasons are not yet clear, but it is believed to have the following effects.

[0367] The adhesive layers in the optical laminate, such as the first bonding layer 150, the second bonding layer 40, and the outer adhesive layer 400, typically contain additives such as unreacted monomers and residual polymerization initiators. These components migrate to the linear polarizer 220 under humid and hot conditions, and can act as acidic components to cause hydrolysis of the cross-linked structures of borate esters in the linear polarizer. As a result, it is inferred that the degree of cross-linking of the linear polarizer decreases, and the thickness of the linear polarizer increases.

[0368] Examples of adhesive layers that include components that function as acidic components and are transported to a linear polarizer include, for instance, adhesive layers comprising adhesive compositions based on acrylic resin polymers, and adhesive layers comprising cationic polymeric adhesives and free radical polymeric adhesives. More specifically, unreacted monomers in the aforementioned adhesive layers and free radical polymeric adhesives can be included as components, and residual polymerization initiators in the cationic polymeric adhesives can also be included as components.

[0369] Furthermore, when the second protective film 190 is a triacetyl cellulose resin film, the increase in the thickness of the linear polarizer becomes more significant because acetic acid is generated through hydrolysis in a humid and hot environment and added to the aforementioned acidic components.

[0370] In this embodiment, by having a second resin layer in addition to the first resin layer between the linear polarizer 220 and the first bonding layer 150, the aforementioned acid components that move from the first bonding layer 150, the second bonding layer 40, the outer adhesive layer 400, and other layers closer to the phase difference portion 300 side of the linear polarizer 220 towards the linear polarizer 220 can be blocked. Therefore, the increase in the thickness of the linear polarizer in a humid and hot environment can be suppressed.

[0371] Furthermore, if the second resin layer contains a compound containing nitrogen atoms, it functions as a base to neutralize the acidic component when it moves towards it, thus providing a higher blocking effect against acidic components. Particularly when the second protective film is a triacetyl cellulose-based resin film, it is suitable for the second resin layer to be in contact with either the linear polarizer side or the phase difference side of the second protective film, since it can neutralize the acetic acid produced by the adjacent second protective film.

[0372] In this case, if the ratio of the mass of N atoms in the thickness direction section of the second resin layer to the total mass of N and O atoms is set to within the range of 1 to 10% by mass, the decrease in the polarization degree of the linear polarizer after exposure to a humid and hot environment can be further suppressed, and is therefore preferred. If the N atom concentration in the second resin layer is too high, it is assumed that the polarization degree decreases due to the alkalinity of the compound containing N atoms.

[0373] Furthermore, from the viewpoint of further suppressing the reduction of polarization degree under humid and hot conditions, in order to separate the linear polarizer 220 from the second resin layer containing the compound containing N atoms, the second resin layer containing the compound containing N atoms is preferably located at a position closer to the phase difference side than the second protective film, for example, in contact with the surface of the second protective film on the phase difference side.

[0374] <Image display device>

[0375] An image display device comprises an optical laminate and an image display element (such as an organic EL display element). The optical laminate is disposed on the viewing side of the image display element (image display unit). An adhesive layer can be used to bond the optical laminate to the image display element.

[0376] There are no particular limitations on image display elements. Examples include organic electroluminescent (organic EL) display elements, inorganic electroluminescent (inorganic EL) display elements, liquid crystal display elements, and electroluminescent display elements.

[0377] Image display devices can be used in mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signage, measuring or measuring instruments, office equipment, medical equipment, electronic computing devices, etc.

[0378] Example

[0379] The present invention will now be described in more detail with reference to embodiments and comparative examples, but the present invention is not limited to the following embodiments. Unless otherwise specified, “%” and “parts” in the examples refer to mass percentage and mass parts, respectively.

[0380] <Example 1>

[0381] 1. Fabrication of polarizing plates

[0382] (1) Preparation of the first protective film

[0383] A COP film with a surface treatment layer, formed by coating a 3μm thick surface treatment agent manufactured by Nippon Paper Corporation onto a cyclic olefin polymer (COP) film (ZF-14, manufactured by ZEON Corporation of Japan, 23μm thick), is used as the first protective film.

[0384] (2) Fabrication of polarizers

[0385] A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2,400, and a saponification degree of 99.9% or higher was dry-stretched uniaxially to a stretch ratio of 4.5 times. While maintaining tension, it was immersed for 60 seconds at 28°C in a dyeing bath containing 0.05 parts by weight of iodine and 5 parts by weight of potassium iodide per 100 parts by weight of water. Next, it was immersed for 155 seconds at 64°C in an aqueous boric acid solution 1 containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water. Next, it was immersed for 30 seconds at 67°C in an aqueous boric acid solution 2 containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water. Finally, it was washed with pure water at 3°C ​​and dried to obtain a polarizing film with a thickness of 8 μm.

[0386] (3) Preparation of the second protective film (1) having the second resin layer

[0387] The following second resin layer forming composition (1) was coated onto a triacetyl cellulose (TAC) membrane (KC2UA, manufactured by Konica Minolta Co., Ltd., 25 μm thick, phase difference Rth in the thickness direction = 18 nm). After drying at an air velocity of 5 m / s and 80°C for 60 seconds, the membrane was irradiated with ultraviolet light (nitrogen atmosphere, cumulative light intensity at wavelength 313 nm: 200 mJ / cm²) from the side coated with the second resin layer forming composition (1). 2 The coating is cured by the process, thereby producing a TAC film (second protective film (1)) having a second resin layer (1). The thickness of the second resin layer (1) is 2.0 μm.

[0388] (Composition for forming the second resin layer (1))

[0389] • Pentaerythritol triacrylate (product name "Light Acrylate PE-3A", manufactured by Kyoeisha Chemical Co., Ltd.): 46.7 parts by weight

[0390] • Polymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure 184", manufactured by Ciba Specialty Chemicals): 3 parts by weight

[0391] Leveling agent (product name "BYK333", manufactured by BYK-Chemie: polyether-modified polydimethylsiloxane): 0.3 parts by weight

[0392] Solvent (methyl ethyl ketone (MEK)): 5 parts by weight

[0393] (4) Fabrication of polarizing plate (1)

[0394] A water-based adhesive is applied to one side of the polarizer obtained above, and the COP film side of the first protective film is bonded to it. A water-based adhesive is applied to the other side of the polarizer, and the TAC film side of the second protective film (1) having a second resin layer is bonded to it. By drying, a polarizing plate (1) with protective films on both sides of the polarizer is obtained. The water-based adhesive used here is prepared by adding 3 parts by weight of carboxyl-modified polyvinyl alcohol (Kuraray Poval KL318 manufactured by Kuraray Co., Ltd.) and 1.5 parts by weight of water-soluble polyamide epoxy resin (Sumirez Resin 650 aqueous solution with a solid content of 30% manufactured by Taoka Chemical Industry Co., Ltd.) to 100 parts of water. Thus, a polarizing plate (1) with the structure of first protective film / water-based adhesive / polarizer / water-based adhesive / second protective film (1) (TAC film) / second resin layer (1) is obtained. Here, the water-based adhesive layer is the first resin layer with a thickness of 0.25 μm.

[0395] 2. Fabrication of the first liquid crystal phase retardation layer

[0396] (1) Preparation of compositions for photo-alignment film formation

[0397] The photo-oriented polymer (weight average molecular weight: 50,000, m:n = 50:50) with the structure shown below was manufactured according to the method described in Japanese Patent Application Publication No. 2021-196514. A mixture was obtained by mixing 2 parts of the photo-oriented polymer and 98 parts of cyclopentanone (solvent). The mixture was stirred at 80°C for 1 hour to prepare a composition for forming a photo-oriented film.

[0398] Photooriented materials:

[0399] [Chemical Formula 8]

[0400]

[0401] (2) Manufacturing of polymeric liquid crystal compounds

[0402] Polymerizable liquid crystal compounds (P1) and (P2) having the structures shown below were prepared respectively. Polymerizable liquid crystal compound (P1) was prepared in the same manner as described in Japanese Patent Application Publication No. 2019-003177. Polymerizable liquid crystal compound (P2) was prepared in the same manner as described in Japanese Patent Application Publication No. 2009-173893.

[0403] Polymerizable liquid crystal compound (P1):

[0404] [Chemical Formula 9]

[0405]

[0406] Polymerizable liquid crystal compound (P2):

[0407] [Chemical Formula 10]

[0408]

[0409] A solution was prepared by dissolving 1 mg of a polymeric liquid crystal compound (P1) in 10 mL of chloroform. This solution was then added to a 1 cm long cuvette for measurement, serving as the sample. The sample was placed in a UV-Vis spectrophotometer (Shimadzu Corporation, "UV-2450"), and the absorption spectrum was measured. The wavelength at which maximum absorbance was achieved was read from the obtained absorption spectrum. The maximum absorption wavelength λmax in the wavelength range of 300–400 nm was found to be 356 nm.

[0410] (3) Preparation of polymeric liquid crystal composition (1)

[0411] Polymerizable liquid crystal compound (P1) and polymerizable liquid crystal compound (P2) were mixed at a mass ratio (P1:P2) of 90:10 to obtain a mixture. 0.1 parts by mass of leveling agent "BYK-361N" (manufactured by BM Chemie) and 3 parts by mass of photopolymerization initiator "Irgacure OXE-03" (manufactured by BASF Japan Co., Ltd.) were added to 100 parts by mass of the mixture. N-methyl-2-pyrrolidone (NMP) was further added to the mixture at a solid content (polymerizable liquid crystal compound (P1), (P2), leveling agent, and photopolymerization initiator) of 13%. The mixture was stirred at 80°C for 1 hour to prepare the polymerizable liquid crystal composition (1).

[0412] (4) Fabrication of the first liquid crystal phase reversal layer with substrate

[0413] As a substrate, a biaxially stretched polyethylene terephthalate (PET) film (manufactured by Diafoil Mitsubishi Resin Co., Ltd.) was prepared. The above-mentioned composition for forming a photo-aligned film was coated onto one surface of the substrate 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. Then, a photo-aligned film was obtained by irradiating the film with 100 mJ of polarized ultraviolet light (313 nm reference) using a UV irradiation device (SPOTCURE SP-9, manufactured by USHIO Electric Co., Ltd.). The film thickness of the photo-aligned film, measured using an ellipsometer M-220 manufactured by Nippon Spectrophotometer Co., Ltd., was 100 nm.

[0414] A polymeric liquid crystal composition (1) was coated onto the obtained photoalignment film using a rod coater to form a coated film. The coated film was heated and dried at 120°C for 2 minutes, then cooled to room temperature to obtain a dried film. Next, the dried film was irradiated with a nitrogen atmosphere using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by USHIO Electric Co., Ltd.) at an exposure dose of 500 mJ / cm². 2 Ultraviolet light (365nm reference) is used to solidify a polymeric liquid crystal compound in a horizontally oriented state relative to the in-plane of the substrate, forming a first liquid crystal retardation layer. This results in a laminate comprising a substrate, a photoalignment film, and the first liquid crystal retardation layer. The thickness of the first liquid crystal retardation layer, measured using an Olympus LEXT OLS4100 laser microscope, is 2.0 μm. The first liquid crystal retardation layer is a positive A-plate satisfying nx > ny ≈ nz. The in-plane phase differences of the first liquid crystal retardation layer, measured using a KOBRA-WR microscope manufactured by Oji Corporation, are Re(450) = 122 nm, Re(550) = 140 nm, and Re(650) = 144 nm, exhibiting reciprocal wavelength dispersion.

[0415] 3. Fabrication of the second liquid crystal phase retardation layer

[0416] (1) Preparation of oriented polymer compositions

[0417] An orientation polymer composition was obtained by adding 2-butoxyethanol to Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), a commercially available orientation polymer, at a solid content of 1%.

[0418] (2) Preparation of polymeric liquid crystal composition (2)

[0419] 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. Furthermore, propylene glycol-1-monomethyl ether-2-acetic acid (PGME) was added, and the mixture was stirred at 80°C for 1 hour to prepare the polymerizable liquid crystal composition (2).

[0420] [Table 1]

[0421]

[0422] Polymerizable liquid crystal compound LC242:

[0423] [Chemical Formula 11]

[0424]

[0425] (3) Fabrication of the second liquid crystal phase reversal layer with substrate

[0426] An orientation polymer composition was applied to the surface of a cyclic olefin polymer (COP) (ZEON Corporation, ZF14) using a bar coater and corona-treated with a corona treatment apparatus (AGF-B10; manufactured by Kasuga Electric Co., Ltd.). The coating was dried at 90°C for 1 minute. The thickness of the resulting orientation film was measured using a laser microscope and found to be 30 nm. Next, a polymerizable liquid crystal composition (2) was applied to the orientation film using a bar coater. After drying at 90°C for 1 minute, the dried coating was irradiated with ultraviolet light at an exposure of 1000 mJ / cm² (365 nm reference) under a nitrogen atmosphere using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by USHIO Electric Co., Ltd.), thereby forming a second liquid crystal retardation layer. Thus, a laminate comprising a substrate, an orientation film, and a second liquid crystal retardation layer was obtained. The thickness of the second liquid crystal retardation layer was measured using a laser microscope and found to be 450 nm.

[0427] The phase difference was measured using a KOBRA-WR instrument manufactured by Oji Measurement & Control Co., Ltd. The result was a positive C-plate with Re(550) = 1 nm, Rth(550) = -70 nm, and satisfying nx ≈ ny < nz. It should be noted that the phase difference at the wavelength of COP at 550 nm is approximately 0, therefore it has no effect on this optical characteristic.

[0428] 4. Fabrication of phase difference laminates with substrate

[0429] A first liquid crystal phase reversal layer and a second liquid crystal phase reversal layer with a substrate are bonded together using an acrylic adhesive (a pressure-sensitive adhesive manufactured by Lintec, with a thickness of 5 μm) with the first liquid crystal phase reversal layer side and the second liquid crystal phase reversal layer side as bonding surfaces, respectively, to obtain a phase reversal laminate with a substrate. The phase reversal laminate with a substrate has a layer structure of substrate / photoalignment film / first liquid crystal phase reversal layer / second bonding layer (5 μm adhesive layer) / second liquid crystal phase reversal layer / alignment film / substrate.

[0430] 5. Fabrication of a diaphragm-based circular polarizing plate (1)

[0431] The surface of the second resin layer side of the polarizer (1) is laminated with the surface obtained by peeling off the substrate of the first liquid crystal phase reversal layer side of the phase reversal laminate with the substrate (with photoalignment film residue) using the adhesive composition A described above. Next, ultraviolet light is irradiated from the substrate side of the second liquid crystal phase reversal layer to cure the adhesive composition A, forming an adhesive layer A with a thickness of 2.0 μm as the first bonding layer. During bonding, the angle between the slow axis of the first liquid crystal phase reversal layer and the absorption axis of the linear polarizer is 135°.

[0432] (Preparation of adhesive composition A)

[0433] The following components are combined and mixed, and then degassed to prepare adhesive composition A.

[0434] • Neopentyl glycol diglycidyl ether (trade name: EX-211L, manufactured by Nagase ChemteX Co., Ltd.): 30 parts by weight

[0435] ·3-Ethyl-3{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toa Synthetic Co., Ltd.): 13 parts by weight

[0436] • Bisphenol A type epoxy resin (trade name: EP-4100E, ADEKA Co., Ltd., viscosity 13 Pa·s (temperature 25°C)): 45 parts by weight

[0437] • Aromatic oxobutane compound (trade name: TCM-104, manufactured by TRONLY): 12 parts by weight

[0438] • Cationic polymerization initiator (trade name: CPI-100_50% solution, manufactured by San-Apro Co., Ltd.): 5.5 parts by weight (actual solid content 2.75 parts by weight)

[0439] ·1,4-Diethoxynaphthalene: 1.2 parts by weight

[0440] ·9,10-Dibutoxyanthracene: 1.9 parts by weight

[0441] • Organosilicon-based leveling agent (trade name: KP-341, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.25 parts by weight

[0442] The substrate of the second liquid crystal phase reversal layer was peeled off from the obtained laminate, and the adhesive side of the acrylic adhesive (pressure-sensitive adhesive manufactured by Lintec, 25 μm thick) with a diaphragm was bonded to it to fabricate a diaphragm-coated circular polarizer (1). The diaphragm-coated circular polarizer (1) sequentially comprises a first protective film (surface treatment layer / COP film) / aqueous adhesive / polarizer / aqueous adhesive (first resin layer) / second protective film (1) (TAC film) / second resin layer / first bonding layer (adhesive layer) / photoalignment film / first liquid crystal phase reversal layer / second bonding layer (5 μm adhesive layer) / second liquid crystal phase reversal layer / alignment film / adhesive layer (25 μm adhesive layer) / diaphragm.

[0443] <Example 2>

[0444] The second resin layer forming composition (1) was changed to the second resin layer forming composition (2) described below. Otherwise, the same procedure as in Example 1 was followed to produce a diaphragm-coated circular polarizing plate (2).

[0445] (Composition for forming the second resin layer (2))

[0446] • Pentaerythritol triacrylate (product name "Light Acrylate PE-3A", manufactured by Kyoeisha Chemical Co., Ltd.): 46.7 parts by weight

[0447] • Polymerization initiator (2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butane-1-one, product name "Irgacure 369", manufactured by BASF Japan): 3 parts by weight

[0448] Leveling agent (product name "BYK333", manufactured by BYK-Chemie: polyether-modified polydimethylsiloxane): 0.3 parts by weight

[0449] Solvent (methyl ethyl ketone (MEK)): 5 parts by weight

[0450] <Example 3>

[0451] The second resin layer forming composition (1) was changed to the second resin layer forming composition (3) described below. Otherwise, the same procedure as in Example 1 was followed to produce a diaphragm-coated circular polarizing plate (3).

[0452] (Composition for forming the second resin layer (3))

[0453] ·4-Acryloylmorpholine (manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd.): 46.7 parts by weight

[0454] • Polymerization initiator (2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butane-1-one, product name "Irgacure 369", manufactured by BASF Japan): 3 parts by weight

[0455] Leveling agent (product name "BYK333", manufactured by BYK-Chemie: polyether-modified polydimethylsiloxane): 0.3 parts by weight

[0456] Solvent (methyl ethyl ketone (MEK)): 5 parts by weight

[0457] <Example 4>

[0458] The second resin layer forming composition (1) was changed to the second resin layer forming composition (4) described below. Otherwise, the same procedure as in Example 1 was followed to produce a diaphragm-coated circular polarizing plate (4).

[0459] (Composition for forming the second resin layer (4))

[0460] • N,N-Dimethylacrylamide (manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd.): 46.7 parts by weight

[0461] • Polymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure 184", manufactured by Ciba Specialty Chemicals): 3 parts by weight

[0462] Leveling agent (product name "BYK333", manufactured by BYK-Chemie: polyether-modified polydimethylsiloxane): 0.3 parts by weight

[0463] Solvent (methyl ethyl ketone (MEK)): 5 parts by weight

[0464] <Example 5>

[0465] The second resin layer forming composition (1) was changed to the second resin layer forming composition (5) described below. Otherwise, the same procedure as in Example 1 was followed to produce a diaphragm-coated circular polarizing plate (5).

[0466] (Composition for forming the second resin layer (5))

[0467] • N,N-Dimethylacrylamide (manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd.): 46.7 parts by weight

[0468] • Polymerization initiator (2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butane-1-one, product name "Irgacure 369", manufactured by BASF Japan): 3 parts by weight

[0469] Leveling agent (product name "BYK333", manufactured by BYK-Chemie: polyether-modified polydimethylsiloxane): 0.3 parts by weight

[0470] Solvent (methyl ethyl ketone (MEK)): 5 parts by weight

[0471] <Example 6>

[0472] The thickness of the second resin layer was changed from 2.0 μm to 4.0 μm. Otherwise, the same procedure as in Example 5 was followed to produce a diaphragm-coated circular polarizing plate (6).

[0473] <Example 7>

[0474] The thickness of the second resin layer was changed from 2.0 μm to 6.0 μm. Otherwise, the same procedure as in Example 5 was followed to produce a diaphragm-coated circular polarizing plate (7).

[0475] <Example 8>

[0476] In the manufacture of the polarizing plate, the second resin layer side of the second protective film having the second resin layer is bonded to the polarizer. Otherwise, the same procedure as in Example 2 is followed to manufacture a circular polarizing plate (8) with a diaphragm. The circular polarizing plate (8) with a diaphragm sequentially comprises a first protective film (surface treatment layer / COP film) / water-based adhesive / polarizer / water-based adhesive (first resin layer) / second resin layer / second protective film (TAC film) / first bonding layer (adhesive layer) / photoalignment film / first liquid crystal phase retardation layer / second bonding layer (5μm adhesive layer) / second liquid crystal phase retardation layer / alignment film / adhesive layer (25μm adhesive layer) / diaphragm.

[0477] <Example 9>

[0478] In the fabrication of the phase retardation laminate with a substrate, the second bonding layer was changed from an adhesive to adhesive layer A. Otherwise, the same procedure as in Example 8 was followed to fabricate a circular polarizer (9) with a diaphragm. The circular polarizer (9) with a diaphragm sequentially comprises a first protective film (surface treatment layer / COP film) / aqueous adhesive / polarizer / aqueous adhesive (first resin layer) / second resin layer / second protective film (TAC film) / first bonding layer (adhesive layer A) / photoalignment film / first liquid crystal phase retardation layer / second bonding layer (adhesive layer A) / second liquid crystal phase retardation layer / alignment film / adhesive layer (25μm adhesive layer) / diaphragm. In addition, the thickness of adhesive layer A forming the second bonding layer is 1.5μm.

[0479] <Comparative Example>

[0480] A second resin layer is not formed on the second protective film. Otherwise, the same procedure as in Example 1 is followed to produce a diaphragm-coated circular polarizing plate (10).

[0481] (evaluate)

[0482] [N atom concentration in the second resin layer]

[0483] The nitrogen (N) atom concentration in the second resin layer was determined using scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDX). Specifically, SEM images were obtained by observing the side of the second protective film using a ZEISS ULTRA55 under the following conditions. Next, the second resin layer from the SEM images was extracted and EDX measurements were performed using an Oxford Instruments UltimMax100 spectrometer. The mass ratio of N to the total mass of N and O in the hard coating cross-section was calculated using EDX measurements and used as the N atom concentration in the second resin layer. The evaluation results are shown in Tables 2 and 3.

[0484] (SEM observation conditions)

[0485] Accelerating voltage: 5kV

[0486] Aperture: 30μm

[0487] WD: 8.5mm

[0488] High current: OFF

[0489] Multiplier: x1000

[0490] Acquisition time: 100 seconds

[0491] Drift correction: Automatic

[0492] [Evaluation of polarizer coating before and after damp heat durability]

[0493] The circular polarizers prepared in the examples and comparative examples were bonded to alkali-free glass plates (Corning's "Eagle-XG") via an adhesive layer as evaluation samples. These evaluation samples were pressurized in an autoclave at 50°C and 5 MPa for 20 minutes, and then placed in an atmosphere of 23°C and 60% relative humidity for one day. Next, layer cross-section analysis was performed using a surface condition observation device (trade name: scanning white interference microscope (vertscan), Hitachi High-Tech Science Co., Ltd.). Depth information for each interface was extracted from the relationship between the interference light obtained from each interface and the height position of the lens, as well as information such as the refractive index of each layer. The film thickness of each layer was then measured, and the polarizer film thickness was determined. After being placed in an environment of 85°C and 85% RH for 504 hours, the polarizer film thickness was similarly measured, the film thickening ratio of the polarizer was calculated, and the evaluation was performed according to the following criteria. The results are shown in Tables 2 and 3.

[0494] (Measurement conditions)

[0495] XY dimensions: 480×480 (1949.679×1041.344 (um))

[0496] Camera: High image quality

[0497] Zoom lens: 1×

[0498] Lens tube: 0.5×

[0499] Light source: 530 white

[0500] Measurement mode: Wave (piezoelectric)

[0501] Objective lens: 5XTI

[0502] Evaluation Criteria:

[0503] A: Above 0.0% and less than 5.0%

[0504] B: Above 5.0% and less than 8.0%

[0505] C: Above 8.0% and less than 10.0%

[0506] D: 10.0% or more

[0507] [Evaluation of the change in polarization degree before and after damp heat durability]

[0508] The circularly polarizing plates prepared in the examples and comparative examples were bonded to alkali-free glass plates (Eagle-XG, manufactured by Corning) via an adhesive layer as evaluation samples. These evaluation samples were pressurized in an autoclave at 50°C and 5 MPa for 20 minutes, and then placed in an atmosphere of 23°C and 60% relative humidity for one day. Next, the degree of polarization (Py) was measured using a UV-Vis-NIR spectrophotometer (V7100, manufactured by Nippon Spectrophotometer Co., Ltd.). Then, after being placed in an environment of 85°C and 85% RH for 336 hours, Py was measured again, and the absolute value of the change in Py (|ΔPy|) was calculated. Evaluation was performed according to the following criteria. The results are shown in Tables 2 and 3.

[0509] Evaluation Criteria:

[0510] A: 0 or higher and less than 5

[0511] B: 5 or more and less than 20

[0512] C: 20 or higher and less than 60

[0513] D: 60 and above

[0514] The conditions and evaluations are shown in Tables 2 and 3.

[0515] [Table 2]

[0516]

[0517] [Table 3]

[0518]

Claims

1. An optical laminate, comprising sequentially a polarizing plate, a first bonding layer, and a phase retardation portion comprising at least one liquid crystal phase retardation layer, The polarizing plate, starting from the side opposite to the phase difference portion, sequentially comprises a first protective film, a linear polarizer, a first resin layer, and a second protective film. The polarizing plate further includes a second resin layer disposed between the first resin layer and the first bonding layer.

2. The optical laminate according to claim 1, wherein, The second resin layer is in contact with the second protective film.

3. The optical laminate according to claim 1, wherein, The second resin layer is in contact with the side of the phase difference portion of the second protective film.

4. The optical laminate according to claim 1, wherein, The second resin layer contains a compound containing nitrogen atoms.

5. The optical laminate according to claim 4, wherein, The second resin layer is a cured product of a polymeric composition comprising a polymeric compound and a photopolymerization initiator, wherein the N-atom-containing compound is derived from the photopolymerization initiator.

6. The optical laminate according to claim 4 or 5, wherein, The mass ratio of N atoms in the thickness direction section of the second resin layer to the total mass of N atoms and O atoms is 1% to 10% by mass.

7. The optical laminate according to claim 4 or 5, wherein, The product of the mass ratio (mass%) of N atoms in the thickness direction section of the second resin layer relative to the total mass of N atoms and O atoms and the thickness (μm) of the second resin layer is 3 (mass%·μm) to 50 (mass%·μm).

8. The optical laminate according to claim 1 or 2, wherein, The thickness of the second resin layer is 0.1 μm to 10 μm.

9. The optical laminate according to claim 1 or 2, wherein, The second protective film is a triacetyl cellulose resin film.

10. The optical laminate according to claim 1 or 2, wherein, The phase difference section includes a first liquid crystal phase difference layer and a second liquid crystal phase difference layer.

11. The optical laminate according to claim 1 or 2, which satisfies the following relationship between equations (1) and (2), 100nm≤Re(550)≤180nm (1) Re(450) / Re(550)≤1.00 (2) In equations (1) and (2), Re(450) represents the in-plane phase difference value in nm for light with a wavelength of 450 nm. Re(550) represents the in-plane phase difference value in nm for light with a wavelength of 550 nm.

12. The optical laminate according to claim 1 or 2, wherein, The first bonding layer is a cured product of an active energy radiation-cured adhesive.

13. The optical laminate according to claim 1 or 2, wherein, The first bonding layer is a cured product of an active energy radiation-cured adhesive.

14. The optical laminate according to claim 1 or 2, wherein, The linear polarizer is a polarizer formed by oriented iodine adsorption onto a polyvinyl alcohol-based resin film.

15. An image display device comprising the optical laminate and image display unit as described in claim 1 or 2.

Images