Optical laminate and image display device

Abstract

The present invention addresses the problem of providing: an optical laminate which has good adhesion between a UV adhesive layer and a retardation film that is formed using a silicon-based or alkyl-based leveling agent; and an image display device. An optical laminate according to the present invention has at least one retardation film and an adhesive layer, which is obtained by curing an ultraviolet-curable adhesive, adjacent to each other, in which: the retardation film is a liquid crystal cured layer obtained by fixing the alignment state of a liquid crystal composition containing a polymerizable liquid crystal compound and a silicon-based or alkyl-based leveling agent; the leveling agent is unevenly distributed on the adhesive-layer side of the retardation film; the ultraviolet-curable adhesive contains a polymerization initiator or a polymerization initiator decomposition product; and the permeation thickness of the polymerization initiator or the polymerization initiator decomposition product in the retardation film is 30 nm to 300 nm.

Description

Optical laminates and image display devices

[0001] This invention relates to an optical laminate and an image display device.

[0002] Optical films, such as optical compensation sheets and phase difference films, are used in various image display devices to eliminate image coloration or expand the viewing angle. While stretched birefringent films were previously used as optical films, in recent years, it has been proposed to use optical films having a liquid crystal curing layer made of liquid crystal compounds instead of stretched birefringent films.

[0003] A liquid crystal cured layer made of a liquid crystal compound is often formed by applying a liquid crystal composition containing the liquid crystal compound to form a liquid crystal composition layer, and then performing an orientation treatment on the liquid crystal composition layer. In the liquid crystal composition layer, a leveling agent may be added to improve the surface properties of the layer surface. For example, Patent Document 1 discloses a liquid crystal composition layer to which a fluorine-based leveling agent containing fluorine atoms has been added.

[0004] Japanese Patent Publication No. 2023-108591

[0005] Recently, due to their persistent nature and toxicity, regulations on PFAS (perfluoroalkyl and polyfluoroalkyl compounds) have been progressing, and the use of alternatives that do not use fluorine atoms, typically alternative materials containing silicon atoms, is being considered. In conjunction with the above regulations, silicon-based or alkyl-based leveling agents are being investigated.

[0006] Recently, there has been a demand for phase difference films that exhibit excellent adhesion to adhesive layers formed by the curing of ultraviolet-curing adhesives (hereinafter also abbreviated as "UV adhesive (UV: ultra violet)"). More specifically, there is a demand for phase difference films that exhibit excellent adhesion to the UV adhesive layer formed by the curing of the UV adhesive when the film is brought into contact with the UV adhesive and cured by ultraviolet irradiation. In particular, it is desirable for the phase difference film to exhibit excellent adhesion to the UV adhesive layer formed by the curing of UV adhesives containing cationic polymerizable compounds.

[0007] Therefore, the object of the present invention is to provide an optical laminate and an image display device that have good adhesion between a phase difference film formed using a silicon-based or alkyl-based leveling agent and a UV adhesive layer.

[0008] The inventors of the present invention diligently studied to achieve the above objectives and found that by unevenly distributing a silicon-based or alkyl-based leveling agent on the UV adhesive layer side of the phase difference film, and by setting the penetration thickness of the polymerization initiator or polymerization initiator decomposition product contained in the UV adhesive into the phase difference film to 30 to 300 nm, good adhesion between the phase difference film and the UV adhesive layer is achieved, thus completing the present invention. In other words, the inventors of the present invention found that the above objectives can be solved by the following configuration.

[0009] [1] An optical laminate having at least one phase difference film and an adhesive layer formed by curing an ultraviolet-curable adhesive adjacent to each other, wherein the phase difference film is a liquid crystal cured layer formed by fixing the orientation state of a liquid crystal composition containing a polymerizable liquid crystal compound and a silicon-based or alkyl-based leveling agent, the leveling agent is biased toward the adhesive layer side of the phase difference film, the ultraviolet-curable adhesive contains a polymerization initiator or a polymerization initiator decomposition product, and the penetration thickness of the polymerization initiator or polymerization initiator decomposition product in the phase difference film is 30 to 300 nm. Here, the penetration thickness of the polymerization initiator or polymerization initiator decomposition product in the phase difference film is defined as the thickness of the region including the surface on the adhesive layer side of the phase difference film, where time-of-flight secondary ion mass spectrometry is performed while irradiating the phase difference film from the adhesive layer side surface toward the surface opposite the adhesive layer, and the secondary ion intensity of the component derived from the polymerization initiator or polymerization initiator decomposition product is measured, and the ratio of the secondary ion intensity I of the component derived from the polymerization initiator or polymerization initiator decomposition product in the phase difference film to the average value Imin of the secondary ion intensity of the component derived from the polymerization initiator or polymerization initiator decomposition product in the central region from the adhesive layer side surface of the phase difference film to a depth position corresponding to 48% to 52% of the total thickness of the phase difference film satisfies the following formula (I-1): 2 ≤ I / Imin (I-1) [2] The optical laminate according to [1], wherein the ratio of the penetration thickness of the polymerization initiator or polymerization initiator decomposition product to the thickness of the region in which the leveling agent is unevenly distributed in the phase difference film is 2.0 to 50.Here, the thickness of the region in the phase difference film where the leveling agent is unevenly distributed is defined as the thickness of the region including the surface of the adhesive layer of the phase difference film, where, when an ion beam is irradiated from the surface on the adhesive layer side of the phase difference film toward the surface opposite the adhesive layer, and the secondary ion intensity of the component derived from the leveling agent is measured, the ratio of the secondary ion intensity L of the component derived from the leveling agent in the phase difference film to the average value Lmin of the secondary ion intensity of the component derived from the leveling agent in the central region from the surface on the adhesive layer side of the phase difference film to a depth position corresponding to 48% to 52% of the total thickness of the phase difference film satisfies the following formula (I-2): 2 ≤ L / Lmin (I-2) [3] The optical laminate according to [1] or [2], wherein the reaction rate of acrylate or methacrylate in the phase difference film is 50 to 80%. [4] The optical laminate according to any one of [1] to [3], wherein the liquid crystal composition contains 20 to 80% by mass of monofunctional polymerizable liquid crystal compounds based on the total mass of polymerizable liquid crystal compounds contained in the liquid crystal composition. [5] The optical laminate according to any one of [1] to [4], wherein the ultraviolet-curable adhesive contains 8 to 80% by mass of polymerizable compounds with a molecular weight of 200 or less based on the total mass of polymerizable compounds contained in the ultraviolet-curable adhesive. [6] The optical laminate according to any one of [1] to [5], wherein the leveling agent has repeating units A containing silicon atoms or alkyl groups, and the content of repeating units A is 30 to 90% by mass of the total repeating units of the leveling agent. [7] The optical laminate according to any one of [1] to [6], wherein the leveling agent has repeating units B containing radical polymerizable groups or cationic polymerizable groups. [8] The optical laminate according to [7], wherein the content of repeating units B is 3 to 50% by mass of the total repeating units of the leveling agent. [9] The optical laminate according to [7] or [8], wherein the number of atoms in the side chain of repeating unit B, from the atom directly bonded to the main chain to the radical polymerizable group or cationic polymerizable group, is 7 or more.

[10] The optical laminate according to any one of [1] to [9], wherein the surface free energy of the adhesive layer side surface of the phase difference film is 22 to 32 mN / m.

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

[10] , wherein the phase difference film is a positive C plate.

[12] An optical laminate according to

[11] , wherein the thickness of the positive C plate is 3 μm or less.

[13] An optical laminate according to

[11] or

[12] , further comprising an alignment film adjacent to the positive C plate.

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

[13] , further comprising a polarizer.

[15] An image display device having the optical laminate according to

[14] .

[0010] According to the present invention, it is possible to provide an optical laminate and an image display device that exhibit good adhesion between a phase difference film formed using a silicon-based or alkyl-based leveling agent and a UV adhesive layer.

[0011] The present invention will now be described in detail. The following descriptions of constituent elements may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, numerical ranges expressed using "~" mean ranges that include the numbers written before and after "~" as the lower and upper limits. In this specification, an upper or lower limit stated in a numerical range described in steps may be replaced with an upper or lower limit in another numerical range described in steps. In addition, an upper or lower limit stated in a numerical range described in this specification may be replaced with a value shown in the examples. In this specification, each component may be made by using one substance alone or by using two or more substances in combination. Here, when two or more substances are used in combination for each component, the content for that component refers to the total content of the substances used in combination, unless otherwise specified.

[0012] In this specification, Re(λ) and Rth(λ) represent the in-plane retardation and thickness-direction retardation at wavelength λ, respectively. Unless otherwise specified, wavelength λ is assumed to be 550 nm. Furthermore, in this specification, Re(λ) and Rth(λ) are values ​​measured at wavelength λ using an AxoScan OPMF-1 (manufactured by OptoScience Co., Ltd.). Specifically, by inputting the average refractive index ((nx + ny + nz) / 3) and film thickness (d) into the AxoScan OPMF-1, the following can be calculated in the slow-speed axis direction (°): Re(λ) = R0(λ) Rth(λ) = ((nx + ny) / 2 - nz) × d Note that R0(λ) is displayed as a value calculated by the AxoScan OPMF-1, but it means Re(λ).

[0013] In this specification, examples of substituents (monovalent substituents) include the substituents listed in substituent group A below. In this specification, "may have substituents" includes not only embodiments without substituents but also embodiments having one or more substituents. <Substituent Group A> Substituents include, for example, halogen atoms (e.g., fluorine atoms, chlorine atoms, bromine atoms); alkyl groups (preferably C1 to C48, more preferably C1 to C24, particularly preferably C1 to C8 alkyl groups, for example, C1 to C6 linear alkyl groups, C3 to C6 branched alkyl groups, C3 to C12 cyclic alkyl groups); alkenyl groups (preferably C2 to C48, more preferably C2 to C18 alkenyl groups); alkynyl groups (preferably C2 to C6, more preferably C2 to C4 alkynyl groups); aryl groups (preferably C6 to C48, more preferably C6 to C24 aryl groups); heteroaryl groups (preferably C1 to C32, more preferably C1 to C18 heterocyclic groups); arylalkyl groups (preferably C7 to C15 arylalkyl groups); silyl groups (preferably C3 to C38, more preferably C3 to C18 silyl groups); Hydroxy group; cyano group; nitro group; morpholino group; alkoxy group (preferably alkoxy groups having 1 to 48 carbon atoms, more preferably alkoxy groups having 1 to 24 carbon atoms); aryloxy group (preferably aryloxy groups having 6 to 48 carbon atoms, more preferably aryloxy groups having 6 to 24 carbon atoms); alkenyloxy group (preferably alkenyloxy groups having 2 to 6 carbon atoms); heterocyclic oxy group (preferably heterocyclic oxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms); silyloxy group (preferably silyloxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms); acyloxy group (preferably acyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms); hydroxyalkyleneoxy group (preferably hydroxyalkyleneoxy groups having 2 to 10 carbon atoms); alkoxycarbonyloxy group (preferably alkoxycarbonyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms);Aryloxycarbonyloxy group (preferably aryloxycarbonyloxy group having 7 to 32 carbon atoms, more preferably aryloxycarbonyloxy group having 7 to 24 carbon atoms); Carbamoyloxy group (preferably carbamoyloxy group having 1 to 48 carbon atoms, more preferably aryloxycarbonyloxy group having 1 to 24 carbon atoms); Sulfamoyloxy group (preferably sulfamoyloxy group having 1 to 32 carbon atoms, more preferably aryloxycarbonyloxy group having 1 to 24 carbon atoms); Alkylsulfonyloxy group (preferably arylsulfonyloxy group having 6 to 32 carbon atoms, more preferably arylsulfonyloxy group having 6 to 24 carbon atoms); Acyl group (preferably acyl group having 1 to 48 carbon atoms, more preferably acyl group having 1 to 24 carbon atoms); Alkoxycarbonyl group (preferably alkoxycarbonyl group having 2 to 48 carbon atoms, more preferably alkoxycarbonyl group having 2 to 24 carbon atoms); Aryloxycarbonyl group (preferably aryloxycarbonyl group having 7 to 32 carbon atoms, more preferably aryloxycarbonyl group having 7 to 24 carbon atoms); Carbamoyl group (preferably a carbamoyl group having 1 to 48 carbon atoms, more preferably a carbamoyl group having 1 to 24 carbon atoms); Amino group (preferably an amino group having 32 or fewer carbon atoms, more preferably an amino group having 24 or fewer carbon atoms); Anilino group (preferably an anilino group having 6 to 32 carbon atoms, more preferably an anilino group having 6 to 24 carbon atoms); Heterocyclic amino group (preferably a heterocyclic amino group having 1 to 32 carbon atoms, more preferably a heterocyclic amino group having 1 to 18 carbon atoms); Carbonamide group (preferably a carbonamide group having 2 to 48 carbon atoms, more preferably a carbonamide group having 2 to 24 carbon atoms); Ureido group (preferably a ureido group having 1 to 32 carbon atoms, more preferably a carbonamide group having 1 to 24 carbon atoms); Imide group (preferably an imide group having 36 or fewer carbon atoms, more preferably an imide group having 24 or fewer carbon atoms); Alkoxycarbonylamino group (preferably an alkoxycarbonylamino group having 2 to 48 carbon atoms, more preferably an alkoxycarbonylamino group having 2 to 24 carbon atoms); Sulfonamide group (preferably a sulfonamide group having 1 to 48 carbon atoms, more preferably a sulfonamide group having 1 to 24 carbon atoms); sulfamoylamino group (preferably a sulfamoylamino group having 1 to 48 carbon atoms, more preferably a sulfamoylamino group having 1 to 24 carbon atoms);Azo group (preferably C1-C32, more preferably C1-C24 azo group); alkylthio group (preferably C1-C48, more preferably C1-C24 alkylthio group); arylthio group (preferably C6-C48, more preferably C6-C24 arylthio group); heterocyclic thio group (preferably C1-C32, more preferably C1-C18 heterocyclic thio group); alkylsulfinyl group (preferably C1-C32, more preferably C1-C24 alkylsulfinyl group); arylsulfinyl group (preferably C6-C32, more preferably C6-C24 arylsulfinyl group); alkylsulfonyl group (preferably C1-C48, more preferably C1-C24 alkylsulfonyl group); arylsulfonyl group (preferably C6-C48, more preferably C6-C24 arylsulfonyl group); Sulfamoyl group (preferably a sulfamoyl group having 32 or fewer carbon atoms, more preferably a sulfamoyl group having 24 or fewer carbon atoms); phosphonyl group (preferably a phosphonyl group having 1 to 32 carbon atoms, more preferably a phosphonyl group having 1 to 24 carbon atoms); phosphinoylamino group (preferably a phosphinoylamino group having 1 to 32 carbon atoms, more preferably a phosphinoylamino group having 1 to 24 carbon atoms); epoxy group; -NHCOCH; ３ ;-SO ２ NHC ２ H ４ OCH ３ ;-NHSO ２ CH ３ Examples include ;, and two or more of these may be combined. These substituents may be further substituted by other substituents. If there are two or more substituents, they may be the same or different. Also, if possible, they may be bonded to each other to form a ring.

[0014] [Optical Laminate] The optical laminate of the present invention is an optical laminate having adjacent to at least one phase difference film and an adhesive layer (UV adhesive layer) formed by curing an ultraviolet-curable adhesive (UV adhesive). Furthermore, the phase difference film in the optical laminate of the present invention is a liquid crystal cured layer formed by fixing the orientation state of a liquid crystal composition containing a polymerizable liquid crystal compound and a silicon-based or alkyl-based leveling agent. In the present invention, the leveling agent is unevenly distributed on the adhesive layer side of the phase difference film. Furthermore, in the present invention, the ultraviolet-curable adhesive contains a polymerization initiator or a polymerization initiator decomposition product. Moreover, in the present invention, the penetration thickness of the polymerization initiator or the polymerization initiator decomposition product in the phase difference film is 30 to 300 nm. In the present invention, if the optical laminate of the present invention has a phase difference film, an adhesive layer formed by curing the above-mentioned ultraviolet-curable adhesive, and another phase difference film adjacent to each other in this order, then in either of the phase difference films, the leveling agent is unevenly distributed towards the adhesive layer, and the penetration thickness of the polymerization initiator or the polymerization initiator decomposition product is 30 to 300 nm.

[0015] Here, "the leveling agent is unevenly distributed on the adhesive layer side of the phase difference film" means that when performing time-of-flight secondary ion mass spectrometry (TOF-SIMS) while irradiating the phase difference film from the adhesive layer side surface toward the opposite surface, and measuring the secondary ion intensity of the component derived from the leveling agent, the ratio of the secondary ion intensity Lsa of the component derived from the leveling agent on the adhesive layer side surface of the phase difference film to the average value Lmin of the secondary ion intensity of the component derived from the leveling agent in the central region (hereinafter simply abbreviated as "central region of the phase difference film") from the adhesive layer side surface of the phase difference film to a depth corresponding to 48% to 52% of the total thickness of the phase difference film satisfies the following equation (I-3): 2 ≤ Lsa / Lmin (I-3)

[0016] Furthermore, the penetration thickness of polymerization initiators or polymerization initiator decomposition products in a phase difference film is defined as the thickness of the region including the adhesive layer side of the phase difference film, when TOF-SIMS is performed while irradiating the phase difference film from the adhesive layer side surface toward the surface opposite the adhesive layer, and the secondary ionic intensity of components derived from polymerization initiators or polymerization initiator decomposition products is measured, such that the ratio of the secondary ionic intensity I of components derived from polymerization initiators or polymerization initiator decomposition products in the phase difference film to the average value Imin of the secondary ionic intensity of components derived from polymerization initiators or polymerization initiator decomposition products in the central region of the phase difference film satisfies the following formula (I-1). 2 ≤ I / Imin (I-1) In the present invention, the penetration of polymerization initiators or polymerization initiator decomposition products into the phase difference film is formed by a portion of the polymerization initiator or polymerization initiator decomposition products contained in the UV-curable adhesive migrating to the phase difference film during the formation of the adhesive layer. The degree of migration to the phase difference film (i.e., the penetration thickness) can be adjusted by methods such as lowering the crosslinking density of the phase difference film, increasing the affinity with the phase difference film, or lowering the viscosity of the UV-curable adhesive.

[0017] Furthermore, the thickness of the region in the phase difference film where the leveling agent is unevenly distributed (hereinafter also abbreviated as "uneven thickness") is defined as the thickness of the region including the surface on the adhesive layer side of the phase difference film, when TOF-SIMS is performed while irradiating the surface on the adhesive layer side of the phase difference film with an ion beam, and the secondary ion intensity of the component derived from the leveling agent is measured, such that the ratio of the secondary ion intensity L of the component derived from the leveling agent in the phase difference film to the average value Lmin of the secondary ion intensity of the component derived from the leveling agent in the central region of the phase difference film satisfies the following formula (I-2): 2 ≤ L / Lmin (I-2) In the present invention, the uneven distribution of the leveling agent in the phase difference film and its degree (i.e., uneven thickness) can be adjusted, for example, by the type of leveling agent (including the content of repeating units in the case of a high molecular weight substance).

[0018] <TOF-SIMS> The measurement of the secondary ion intensity by the time-of-flight secondary ion mass spectrometry (TOF-SIMS) described in the above description of uneven distribution, penetration thickness, and uneven distribution thickness is preferably carried out using the following apparatus and conditions. In addition, the component of the object that is the source of the secondary ion intensity (that is, the leveling agent, polymerization initiator, or polymerization initiator decomposition product) is not particularly limited as long as it can accurately measure the distribution state of the object. When analyzing the components in the depth direction of the phase difference film by TOF-SIMS while performing ion sputtering, after performing component analysis in the depth region of 1 to 2 nm, further dig 1 to 2 nm in the depth direction and repeat a series of operations of performing component analysis in the next depth region of 1 to 2 nm. Therefore, the secondary ion intensity of each component at the above depth position means the result of component analysis in the depth region of 1 to 2 nm. - Apparatus used: TOF-SIMS 5 (manufactured by ION-TOF) - Primary ion: Bi ３ ＋＋ (Acceleration voltage: 25 to 30 kV) - Measurement area: 300 μm × 300 μm - Polarity: Positive, negative - Ion beam: Ar-GCIB gun (acceleration voltage 5 to 15 kV, 1000 μm × 1000 μm sputtering)

[0019] In the present invention, as described above, by unevenly distributing the silicon-based or alkyl-based leveling agent on the UV adhesive layer side of the phase difference film, and by setting the penetration thickness into the phase difference film by the polymerization initiator or polymerization initiator decomposition product contained in the UV adhesive to 30 to 300 nm, good adhesion between the phase difference film and the UV adhesive layer is achieved. The details of the reason for this are not yet clear, but the inventors speculate that it is due to the following reasons. First, unevenly distributing the silicon-based or alkyl-based leveling agent on the UV adhesive layer side of the phase difference film improves the surface condition of the phase difference film. Unlike fluorine-based leveling agents, silicon-based or alkyl-based leveling agents, when unevenly distributed on the UV adhesive layer side, remain even after surface treatment such as corona treatment, and therefore tend to have inferior adhesion to the UV adhesive layer compared to when a fluorine-based leveling agent is used. In other words, the problem to be solved by the present invention is a problem that is not recognized when a fluorine-based leveling agent is used. Furthermore, by setting the penetration thickness of the polymerization initiator or polymerization initiator decomposition product contained in the UV adhesive into the phase difference film to 30 to 300 nm, it is believed that the adhesion between the phase difference film and the UV adhesive layer was improved due to a so-called anchoring effect.

[0020] [UV Adhesive Layer] The UV adhesive layer of the optical laminate of the present invention is an adhesive layer formed by curing an ultraviolet-curable adhesive (UV adhesive). In the present invention, the UV adhesive contains a polymerization initiator or a polymerization initiator decomposition product. Here, the polymerization initiator contained in the UV adhesive is not particularly limited, but it is preferably a photosensitive compound, i.e., a photopolymerization initiator. Examples of photopolymerization initiators include photoradical polymerization initiators and photocationic polymerization initiators. Examples of photoradical polymerization initiators include photopolymerization initiators having an oxime ester skeleton, photopolymerization initiators having an α-aminoalkylphenone skeleton, photopolymerization initiators having an α-hydroxyalkylphenone skeleton, photopolymerization initiators having an acylphosphine oxide skeleton, and photopolymerization initiators having an N-phenylglycine skeleton. Furthermore, examples of photocationic polymerization initiators include triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, p-(phenylthio)phenyldiphenylsulfonium hexafluoroantimonate, p-(phenylthio)phenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate, and bis[4-(diphenylsulfonio)phenyl]sulfonate. Examples include filtobishexafluorophosphate, bis[4-(diphenylsulfonio)phenyl]sulfidobishexafluoroantimonate, (2,4-cyclopentadien-1-yl)[(1-methylethyl)benzene]-Fe-hexafluorophosphate, and diphenyliodonium hexafluoroantimonate. Among these, triphenylsulfonium salt-based hexafluoroantimonate type photocationic polymerization initiators and diphenyliodonium salt-based hexafluoroantimonate type photocationic polymerization initiators are preferred. Furthermore, the polymerization initiator decomposition products contained in UV adhesives are not particularly limited, but examples include the decomposition products of the polymerization initiators mentioned above.

[0021] In the present invention, for better adhesion between the phase difference film and the UV adhesive layer, the UV adhesive preferably contains 8 to 80% by mass of polymerizable compounds with a molecular weight of 200 or less, and more preferably 8 to 40% by mass, relative to the total mass of polymerizable compounds contained in the UV adhesive.

[0022] Examples of such UV adhesives include radical polymerization-curable adhesives containing radical polymerizable compounds and cationic polymerization-curable adhesives containing cationic polymerizable compounds. Here, the radical polymerizable compound is a compound having a radical polymerizable group, and the cationic polymerizable compound is a compound having a cationic polymerizable group. As the radical polymerizable group, known radical polymerizable groups can be used, and preferred examples include acryloyl groups or methacryloyl groups. In this case, the polymerization rate is generally known to be faster for acryloyl groups, and from the viewpoint of improving productivity, acryloyl groups are preferred, but methacryloyl groups can also be used similarly as polymerizable groups. As the cationic polymerizable group, known cationic polymerizable groups can be used, specifically, alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spiroorthoester groups, and vinyl groups. Among these, alicyclic ether groups or vinyl groups are preferred, and epoxy groups, oxetanyl groups, or vinyl groups are particularly preferred.

[0023] Examples of radical polymerization-curing adhesives and cationic polymerization-curing adhesives include those described in paragraphs

[0067] to

[0077] of Japanese Patent Application Publication No. 2016-035579, which are incorporated herein by reference.

[0024] The UV adhesive layer is formed, for example, by applying a UV adhesive to a phase difference film (described later), then bonding it to a laminate (e.g., another phase difference film or polarizer), and finally curing it. The phase difference film may be subjected to a surface modification treatment beforehand. Examples of surface modification treatments include corona treatment, plasma treatment, and saponification treatment.

[0025] Depending on the viscosity of the UV adhesive and the thickness of the UV adhesive layer, any suitable method can be used for applying the UV adhesive. Examples of application methods include reverse coaters, gravure coaters (direct, reverse, and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, and rod coaters. Dipping methods may also be used for application.

[0026] Any suitable method can be used to cure the UV adhesive. Here, conditions such as the wavelength and amount of ultraviolet light can be set to any suitable conditions depending on the type of curable compound used.

[0027] [Phase Difference Film] The phase difference film of the optical laminate of the present invention is a liquid crystal cured layer obtained by fixing the orientation state of a liquid crystal composition (hereinafter formally abbreviated as "liquid crystal composition of the present invention") which contains a polymerizable liquid crystal compound and a silicon-based or alkyl-based leveling agent. In the present invention, as described above, the leveling agent contained in the liquid crystal composition is predominantly located on the UV adhesive layer side of the phase difference film. Also in the present invention, as described above, the penetration thickness of the polymerization initiator or polymerization initiator decomposition product in the phase difference film is 30 to 300 nm, preferably 50 to 300 nm, and more preferably 80 to 250 nm.

[0028] In the present invention, for better adhesion between the phase difference film and the UV adhesive layer, the ratio of the penetration thickness of the polymerization initiator or polymerization initiator decomposition product to the uneven distribution thickness of the leveling agent in the phase difference film (penetration thickness / uneven distribution thickness) is preferably 2.0 to 50, more preferably 2.5 to 25, and even more preferably 2.5 to 15.

[0029] Furthermore, in this invention, the reaction rate of acrylate or methacrylate in the phase difference film is preferably 50 to 80%, and more preferably 55 to 75%, because it improves the adhesion between the phase difference film and the UV adhesive layer. Here, the reaction rate of acrylate or methacrylate is determined by total internal reflection (ATR) measurement using Fourier transform infrared spectroscopy (FT-IR) at 810 cm² before and after UV irradiation of the phase difference film. －１ It can be calculated from the area ratio of nearby peaks (out-of-plane bending vibrations of the vinyl group in the CH plane).

[0030] Next, the components of the liquid crystal composition of the present invention will be described.

[0031] <Polymerizable Liquid Crystal Compounds> The polymerizable liquid crystal compounds (i.e., liquid crystal compounds having polymerizable groups) contained in the liquid crystal composition of the present invention are not particularly limited. Furthermore, the type of liquid crystal compound is not particularly limited, but generally, liquid crystal compounds can be classified into rod-shaped and disc-shaped types based on their shape. Each of these further has low molecular weight and high molecular weight types. A high molecular weight generally refers to a compound with a degree of polymerization of 100 or more (Polymer Physics and Phase Transition Dynamics, by Masao Doi, p. 2, Iwanami Shoten, 1992).

[0032] In this invention, any liquid crystal compound can be used, but it is preferable to use a rod-shaped liquid crystal compound or a disc-shaped liquid crystal compound (discotic liquid crystal compound). Two or more rod-shaped liquid crystal compounds, two or more disc-shaped liquid crystal compounds, or a mixture of rod-shaped and disc-shaped liquid crystal compounds may also be used.

[0033] As the rod-shaped liquid crystal compound, for example, the one described in claim 1 of Japanese Patent Publication No. 11-513019 or paragraphs

[0026] to

[0098] of Japanese Patent Application Publication No. 2005-289980 is preferred, and as the disc-shaped liquid crystal compound, for example, the one described in paragraphs

[0020] to

[0067] of Japanese Patent Application Publication No. 2007-108732 or paragraphs

[0013] to

[0108] of Japanese Patent Application Publication No. 2010-244038 is preferred.

[0034] The orientation of a polymerizable liquid crystal compound can be fixed by polymerization. Furthermore, after the liquid crystal compound has been fixed by polymerization, it no longer needs to exhibit liquid crystalline properties.

[0035] The polymerizable groups of a polymerizable liquid crystal compound are not particularly limited, but examples include radical polymerizable groups and cationic polymerizable groups. Here, examples of radical polymerizable groups and cationic polymerizable groups are the same as those described in the description of the radical polymerizable compounds and cationic polymerizable compounds of UV adhesives mentioned above.

[0036] In the present invention, a polymerizable liquid crystal compound exhibiting inverse wavelength dispersion may be used as the polymerizable liquid crystal compound. Hereinafter, in this specification, a polymerizable liquid crystal compound exhibiting inverse wavelength dispersion refers to a compound in which, when the in-plane retardation (Re) value of a phase difference film made using the same is measured at a specific wavelength (visible light range), the Re value becomes equivalent or higher as the measured wavelength increases.

[0037] The polymerizable liquid crystal compounds with reverse wavelength dispersion are not particularly limited as long as they can form a film with reverse wavelength dispersion. Examples include compounds represented by general formula (I) described in Japanese Patent Application Publication No. 2008-297210 (particularly the compounds described in paragraphs

[0034] to

[0039] ), compounds represented by general formula (1) described in Japanese Patent Application Publication No. 2010-084032 (particularly the compounds described in paragraphs

[0067] to

[0073] ), and compounds represented by general formula (1) described in Japanese Patent Application Publication No. 2016-081035 (particularly the compounds described in paragraphs

[0043] to

[0055] ). Furthermore, examples include the compounds described in paragraphs

[0027] to

[0100] of Japanese Patent Publication No. 2011-006360, paragraphs

[0028] to

[0125] of Japanese Patent Publication No. 2011-006361, paragraphs

[0034] to

[0298] of Japanese Patent Publication No. 2012-207765, paragraphs

[0016] to

[0345] of Japanese Patent Publication No. 2012-077055, paragraphs

[0017] to

[0072] of WO12 / 141245, paragraphs

[0021] to

[0088] of WO12 / 147904, and paragraphs

[0028] to

[0115] of WO14 / 147904.

[0038] In the present invention, the polymerizable liquid crystal compound may be used alone or in combination of two or more types. Furthermore, the content of the polymerizable liquid crystal compound is preferably 10 to 99% by mass, and more preferably 50 to 95% by mass, based on the total solid content (100% by mass) of the liquid crystal composition.

[0039] Furthermore, in the present invention, for better adhesion between the phase difference film and the UV adhesive layer, it is preferable that the liquid crystal composition contains 20 to 80% by mass of monofunctional polymerizable liquid crystal compounds (i.e., liquid crystal compounds having one polymerizable group), more preferably 40 to 75% by mass, and even more preferably 55 to 75% by mass, based on the total mass of polymerizable liquid crystal compounds contained in the liquid crystal composition.

[0040] <Leveling Agent> The leveling agent contained in the liquid crystal composition of the present invention is a silicon-based or alkyl-based leveling agent, and preferably does not contain fluorine atoms.

[0041] In the present invention, it is preferable that the leveling agent is a polymer having repeating units A containing silicon atoms or alkyl groups, and the content of repeating units A is 30 to 90% by mass relative to the total repeating units of the leveling agent, because this increases the amount of uneven distribution towards the adhesive layer side in the phase difference film, and as a result reduces unevenness in color and brightness.

[0042] (Repeating Unit A) Examples of repeating unit A include a repeating unit selected from the group consisting of two or more groups represented by the following formula (Ia), a linear silicone group, and an alkyl group having 10 or more carbon atoms and having two or more terminal methyl groups. Furthermore, repeating unit A may be used alone or in combination of two or more types.

[0043] <Group represented by formula (Ia)> One preferred embodiment of repeating unit A is a repeating unit that includes two or more groups represented by the following formula (Ia).

[0044] In the above formula (Ia), * represents the bond position. ４ , R ５ , and, R ６Each of these independently represents an alkyl group, an alkenyl group, or an aryl group, which may have substituents. Examples of the alkyl group include linear alkyl groups having 1 to 18 carbon atoms, and branched or cyclic alkyl groups having 3 to 18 carbon atoms. Specifically, examples include methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, and cyclohexyl groups. Examples of the alkenyl group include alkenyl groups having 2 to 12 carbon atoms. Examples of the aryl group include aryl groups having 6 to 12 carbon atoms. Furthermore, examples of substituents that the alkyl group may have include the substituents listed in substituent group A above, among which alkyl groups, alkylcarbonyl groups, alkyloxycarbonyl groups, alkylcarbonyloxy groups, or alkoxy groups are preferred. In the present invention, R ４ , R ５ , and, R ６ It is preferable that all of these are alkyl groups, as this suppresses planar unevenness in the phase difference film.

[0045] <Linear Silicone Group> Another preferred embodiment of repeating unit A is a repeating unit containing a linear silicone group. Here, a preferred linear silicone group is, for example, the group represented by the following formula (Ib).

[0046] In the above formula (Ib), * represents the joining position. n represents an integer between 11 and 130. ４ , R ５ , R ６ , R １０ , and, R １１ Each of these independently represents an alkyl group, alkenyl group, or aryl group, which may have substituents. １０ These may be the same or different, and there may be multiple R １１ These may be the same or different.

[0047] As stated above, n in formula (Ib) represents an integer between 11 and 130, but is preferably an integer between 15 and 70, and more preferably an integer between 15 and 65. Also, R in formula (Ib) ４ , R ５ , R ６ , R １０ , and, R １１ For example, R in the above formula (Ia) ４ , R ５ , and, R ６ This is the same as what was explained earlier.

[0048] <Alkyl groups having 10 or more carbon atoms and having two or more terminal methyl groups> Another preferred embodiment of repeating unit A is a repeating unit comprising an alkyl group having 10 or more carbon atoms and having two or more terminal methyl groups. Here, "terminal methyl group" means a methyl group that constitutes the end of a linear or side chain of an alkyl group having 10 or more carbon atoms. For example, linear alkyl groups such as n-propyl and n-butyl groups are alkyl groups having one terminal methyl group, isopropyl groups are alkyl groups having two terminal methyl groups, and t-butyl groups are alkyl groups having three terminal methyl groups. For example, n-decane groups have 10 carbon atoms and are alkyl groups having one terminal methyl group, but any group represented by any of the following formulas (a-1) to (a-4) all have 10 or more carbon atoms and have two or more terminal methyl groups (methyl groups enclosed by dotted lines in the following formulas). The number of terminal methyl groups is two or more, preferably three or more, and more preferably three to ten.

[0049]

[0050] As alkyl groups having 10 or more carbon atoms and having two or more terminal methyl groups, alkyl groups having 10 to 20 carbon atoms are preferred, linear alkyl groups having 10 to 18 carbon atoms, branched alkyl groups having 10 to 18 carbon atoms, or cyclic alkyl groups having 10 to 20 carbon atoms are more preferred, and branched alkyl groups having 10 to 18 carbon atoms are even more preferred.

[0051] In the present invention, it is preferable that the repeating unit A is a repeating unit comprising two or more groups represented by the above formula (Ia), or the linear silicone group described above.

[0052] Furthermore, in the present invention, it is preferable that the repeating unit A is a repeating unit represented by the following formula (a1).

[0053] In the above formula (a1), m represents an integer of 2 or greater. １ and R ２ Each of these independently represents either a hydrogen atom or an alkyl group. ３ L represents a hydrogen atom or substituent. １ is -O- or -NR Ｚ - represents R Ｚ L represents a hydrogen atom or substituent. ２ R represents an m+1 valent linking group. ４ , R ５ , and, R ６ Each of these independently represents an alkyl group, alkenyl group, or aryl group, which may have substituents. However, multiple R ４ These may be the same or different, and there may be multiple R ５ These may be the same or different, and there may be multiple R ６ These may be the same or different. Note that R in formula (a1) above ４ ~R ６ These include the same ones described in equation (Ia) above.

[0054] In the above formula (a1), R １ and R ２ Examples of alkyl groups represented in one embodiment include linear alkyl groups having 1 to 18 carbon atoms, branched alkyl groups having 3 to 18 carbon atoms, or cyclic alkyl groups. Specifically, examples include methyl groups, ethyl groups, propyl groups, butyl groups, isopropyl groups, tert-butyl groups, and cyclohexyl groups. In the present invention, R １ and R ２ Preferably, it is a hydrogen atom.

[0055] In the above formula (a1), R ３ Examples of substituents shown in one aspect include the substituents listed in the substituent group A above (particularly alkyl groups, alkenyl groups, and aryl groups), or substituents having a linking group and a group represented by formula (Ia) above at the terminal end. In the present invention, R ３ Preferably, the group is a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a linear alkyl group having 1 to 4 carbon atoms, even more preferably a hydrogen atom, a methyl group, or an ethyl group, and particularly preferably a hydrogen atom or a methyl group.

[0056] In the above formula (a1), L １ is -O- or -NR Ｚ - represents R Ｚ R represents a hydrogen atom or substituent. Ｚ Examples of substituents represented by include those listed in substituent group A above, among which alkyl groups are preferred, linear alkyl groups having 1 to 4 carbon atoms are more preferred, and methyl or ethyl groups are even more preferred. In the present invention, L １ As for the nucleotide, -O- or -NH- is preferred, and -O- is more preferred.

[0057] As stated above, m in formula (a1) represents an integer of 2 or more, but is preferably an integer of 3 or more, more preferably an integer between 3 and 6, and even more preferably an integer between 3 and 5.

[0058] In the above formula (a1), L ２ As described above, represents an m+1 valent linking group. Examples of the above m+1 valent linking group include, for example, a C1 to C10 m+1 valent hydrocarbon group which may have substituents, and in which some of the carbon atoms constituting the hydrocarbon group may be substituted with heteroatoms. Examples of substituents that the above hydrocarbon group may have include those listed in substituent group A above, among which alkyl groups are preferred, linear alkyl groups having C1 to C4 are more preferred, and methyl or ethyl groups are even more preferred. Examples of heteroatoms that may substitute for some of the carbon atoms include silicon atoms, oxygen atoms, and nitrogen atoms. L ２Examples include the group represented by the structural formula K-1-L, the group represented by the structural formula K-2-L, and the group represented by the structural formula K-3-L shown below. In the lower structural formulas, * represents L in formula (a1). １ This indicates the bond position with, and ** represents the -SiR in equation (a1). ４ R ５ R ６ This represents the bonding position with the group represented by . Of these, L ２ The group represented by the following structural formula K-1-L is preferred.

[0059]

[0060] Specific examples of repeating unit A include, for instance, the repeating units corresponding to the monomers represented by the following formulas A-1 to A-30. In formulas such as A-12, nBu represents an n-butyl group.

[0061]

[0062] (Repeating Unit B) In the present invention, it is preferable that the leveling agent is a polymer having repeating unit B containing a radical polymerizable group or a cationic polymerizable group, for the reason that the adhesion between the phase difference film and the UV adhesive layer is better. Here, the radical polymerizable group and cationic polymerizable group are the same as those described above for the radical polymerizable compound and cationic polymerizable compound of the UV adhesive.

[0063] Furthermore, in the present invention, the content of repeating unit B is preferably 3 to 50% by mass, and more preferably 5 to 20% by mass, relative to the total repeating units of the leveling agent (polymer), in order to further improve the adhesion between the phase difference film and the UV adhesive layer.

[0064] Similarly, in the present invention, for the reason that the adhesion between the phase difference film and the UV adhesive layer is further improved, the number of atoms in the side chain of repeating unit B, from the atom directly bonded to the main chain to the radical polymerizable group or cationic polymerizable group, is preferably 7 or more, and more preferably 8 to 20. The above number of atoms also includes the number of atoms closest to the main chain among the atoms constituting the radical polymerizable group or cationic polymerizable group. Here, in the specific example below, the number of atoms from the atom directly bonded to the main chain to the radical polymerizable group is 7, as specified below. Furthermore, in the following specific examples that have a cyclic cationic polymerizable group (epoxy group), the number of atoms from the atom directly bonded to the main chain to the cationic polymerizable group is 9, as specified below.

[0065] In the present invention, the weight-average molecular weight of the leveling agent is preferably 10,000 or more and 40,000 or less, and more preferably 15,000 or more and 35,000 or less. Here, the weight-average molecular weight in the present invention is the value measured by gel permeation chromatography (GPC) under the following conditions. • Solvent (eluent): Tetrahydrofuran • Instrument name: EcoSEC HLC-8320GPC (Tosoh Corporation) • Columns: Three columns connected together: TSKgel SuperHZM-H, TSKgel SuperHZ4000, and TSKgel SuperHZ200 (all Tosoh Corporation) • Column temperature: 40°C • Sample concentration: 0.1% by mass • Flow rate: 0.35 ml / min • Calibration curve: Calibration curve using six samples of TOSOH TSK standard polystyrene Mw = 706000 to 1013 (Mw / Mn = 1.03 to 1.06) was used.

[0066] In the present invention, the leveling agent may be used alone or in combination of two or more types. Furthermore, the content of the leveling agent is preferably 0.05 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the polymerizable liquid crystal compound described above.

[0067] <Solvent> The liquid crystal composition of the present invention preferably contains a solvent. Examples of solvents include ketones [e.g., acetone, 2-butanone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, cyclopentanone (CPO), etc.], ethers [e.g., dioxane, tetrahydrofuran (THF), propylene glycol monomethyl ether acetate (PGMEA), etc.], aliphatic hydrocarbons [e.g., hexane, etc.], alicyclic hydrocarbons [e.g., cyclohexane, etc.], aromatic hydrocarbons [e.g., toluene, xylene, trimethylbenzene, etc.], and halogenated carbons [e.g., di Examples of solvents include chloromethane, dichloroethane, dichlorobenzene, chlorotoluene, etc., esters (e.g., methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (e.g., methanol (MeOH), ethanol, isopropyl alcohol (IPA), butanol, cyclohexanol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), and amides (e.g., dimethylformamide, dimethylacetamide, etc.). These solvents may be used individually or in combination of two or more.

[0068] <Polymerization Initiator> The liquid crystal composition of the present invention preferably contains a polymerization initiator. As the polymerization initiator, a photopolymerization initiator that can initiate the polymerization reaction by ultraviolet irradiation is preferred. Examples of photopolymerization initiators include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, combinations of triarylimidazole dimers and p-aminophenyl ketones, acridine and phenazine compounds and oxadiazole compounds, acylphosphine oxide compounds, and the like. Oxime-type polymerization initiators are also preferred as polymerization initiators. Specific examples include, for example, the initiators described in paragraphs

[0049] to

[0052] of International Publication No. 2017 / 170443.

[0069] <Other Components> The liquid crystal composition of the present invention may contain other components besides those described above. Examples of other components include tilt angle control agents, plasticizers, and crosslinking agents.

[0070] <Phase Difference Film> As described above, the phase difference film of the optical laminate of the present invention is a liquid crystal cured layer formed by fixing the orientation state of the liquid crystal composition of the present invention. Methods for forming the liquid crystal cured layer include, for example, a method of using the liquid crystal composition of the present invention described above to achieve a desired orientation state, and then fixing it by polymerization. While the conditions for achieving the desired orientation state are not particularly limited, heat treatment is preferred, and cooling treatment after heat treatment is more preferred. The heating temperature in the heat treatment is preferably 10 to 250°C, more preferably 50 to 200°C, and even more preferably 70 to 150°C, from the viewpoint of manufacturability. The heating time in the heat treatment is preferably 1 to 300 seconds, and more preferably 1 to 60 seconds. The temperature in the cooling treatment after heat treatment is not particularly limited as long as it is lower than the heating temperature in the heat treatment, but room temperature (23°C) to 80°C is preferred. While the conditions for polymerization are not particularly limited, ultraviolet light is preferred for polymerization by light irradiation. The irradiation dose is 10 mJ / cm². ２ ~50 J / cm ２ Preferably, 20 mJ / cm ２ ~5J / cm ２ More preferably, 30 mJ / cm ２ ~3J / cm ２ More preferably, 50 to 1000 mJ / cm ２ This is particularly preferable. Furthermore, the polymerization reaction may be carried out under heating conditions to accelerate it.

[0071] The orientation state of the liquid crystal compound in the phase difference film (liquid crystal cured layer) may be any of the following: horizontal orientation, vertical orientation, tilted orientation, or twisted orientation.

[0072] In the present invention, the phase difference film (liquid crystal cured layer) is preferably a positive C plate or a positive A plate, and more preferably a positive C plate.

[0073] Here, a positive C plate is defined as follows: A positive C plate satisfies the relationship in equation (C1), where nx is the refractive index in the slow axis direction within the film plane (the direction in which the refractive index is maximum within the plane), ny is the refractive index in the direction perpendicular to the slow axis within the plane, and nz is the refractive index in the thickness direction. Note that a positive C plate exhibits a negative Rth value. Equation (C1) nz > nx ≈ ny Note that the above "≈" includes not only cases where the two are completely identical, but also cases where they are substantially identical. "Substantially identical" means, for example, that (nx - ny) × d (where d is the thickness of the film) is between 0 and 10 nm, preferably between 0 and 5 nm, which is included in "nx ≈ ny".

[0074] Furthermore, a positive A plate is defined as follows: A positive A plate satisfies the relationship in equation (A1), where nx is the refractive index in the slow axis direction within the film plane (the direction in which the refractive index is maximum within the plane), ny is the refractive index in the direction perpendicular to the slow axis within the plane, and nz is the refractive index in the thickness direction. Note that a positive A plate exhibits a positive Rth value. Equation (A1) nx > ny ≈ nz Note that the above "≈" includes not only cases where the two are completely identical, but also cases where they are substantially identical. "Substantially identical" means, for example, that (nx - ny) × d (where d is the thickness of the film) is -10 to 10 nm, preferably -5 to 5 nm, which is included in "ny ≈ nz".

[0075] Furthermore, in the present invention, the thickness of the phase difference film (liquid crystal cured layer) is not particularly limited, but when the phase difference film is a positive C plate, it is preferably 3 μm or less, and more preferably 0.1 to 1.5 μm.

[0076] Furthermore, in the present invention, it is preferable that the surface free energy of the adhesive layer side surface of the phase difference film is 22 to 32 mN / m, in order to reduce unevenness in color and brightness. Here, the surface free energy (γs ｖ: The unit, mN / m), was experimentally determined on a phase difference film for pure water H ２ O and methylene iodide CH ２ I ２ each contact angle θ Ｈ２Ｏ 、θ ＣＨ２Ｉ２ From the following simultaneous equations a and b, the sum of γs ｄ and γs ｈ The value γs ｖ (=γs ｄ +γs ｈ ). a. 1 + cosθ Ｈ２Ｏ =2√γs ｄ (√γ Ｈ２Ｏ ｄ / γ Ｈ２Ｏ ｖ )+2√γs ｈ (√γ Ｈ２Ｏ ｈ / γ Ｈ２Ｏ ｖ ) b. 1 + cosθ ＣＨ２Ｉ２ =2√γs ｄ (√γ ＣＨ２Ｉ２ ｄ / γ ＣＨ２Ｉ２ ｖ )+2√γs ｈ (√γ ＣＨ２Ｉ２ ｈ / γ ＣＨ２Ｉ２ ｖ ) γ Ｈ２Ｏ ｄ =21.8、γ Ｈ２Ｏ ｈ =51.0、γ Ｈ２Ｏ ｖ =72.8 γ ＣＨ２Ｉ２ ｄ =49.5、γ ＣＨ２Ｉ２ ｈ =1.3、γ ＣＨ２Ｉ２ ｖ =50.8

[0077] [Other Phase Difference Films] The optical laminate of the present invention may have other phase difference films in addition to the phase difference film described above. Other phase difference films include liquid crystal curing layers similar to the phase difference film described above, except that they do not satisfy the requirements regarding the uneven distribution of the leveling agent to the UV adhesive layer side and the penetration of polymerization initiators or polymerization initiator decomposition products. Furthermore, it is preferable that the other phase difference film be a positive A plate. Furthermore, the thickness of the other phase difference film is not particularly limited, but if the other phase difference film is a positive A plate, it is preferably 5 μm or less, and more preferably 1 to 5 μm.

[0078] [Substrate] The optical laminate of the present invention may have a substrate for supporting the above-mentioned phase difference film (including other phase difference films). Such a substrate is preferably transparent. In this invention, "transparent" means that the transmittance of visible light is 60% or more, preferably 80% or more, and more preferably 90% or more.

[0079] Examples of the above-mentioned substrates include glass substrates and polymer films. Examples of polymer film materials include cellulose polymers; acrylic polymers having acrylic acid ester polymers such as polymethyl methacrylate and lactone ring-containing polymers; thermoplastic norbornene polymers; polycarbonate polymers; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); polyolefin polymers such as polyethylene, polypropylene, and ethylene-propylene copolymer; vinyl chloride polymers; amide polymers such as nylon and aromatic polyamides; imide polymers; sulfone polymers; polyethersulfone polymers; polyetheretherketone polymers; polyphenylene sulfide polymers; vinylidene chloride polymers; vinyl alcohol polymers; vinyl butyral polymers; arylate polymers; polyoxymethylene polymers; epoxy polymers; and polymers obtained by mixing these polymers. The thickness of the above-mentioned substrate is not particularly limited, but is preferably 1 to 200 μm, and more preferably 2 to 100 μm.

[0080] [Alignment film] In the case where the phase difference film is a positive C plate, the optical laminate of the present invention may have an alignment film adjacent to the positive C plate.

[0081] The alignment film can be any film that has the function of aligning the liquid crystal compounds contained in the composition. The alignment film is generally composed mainly of a polymer. Numerous polymer materials for alignment films are described in various publications, and many commercially available products are available. Preferred polymer materials for alignment films are polyvinyl alcohol, polyimide, or derivatives thereof, with modified or unmodified polyvinyl alcohol being more preferred. Other suitable polymer materials for alignment films include, for example, thiol compounds, monofunctional (meth)acrylic compounds, and polyfunctional (meth)acrylate compounds. Examples of alignment films include the alignment film described on page 43, line 24 to page 49, line 8 of International Publication No. 01 / 88574; the alignment film made of modified polyvinyl alcohol described in paragraphs

[0071] to

[0095] of Japanese Patent No. 3907735; and the liquid crystal alignment film formed by the liquid crystal alignment agent described in Japanese Patent Application Publication No. 2012-155308; and the alignment film described in paragraphs

[0018] to

[0044] of Japanese Patent Application Publication No. 2020-204738. The thickness of the above alignment film is not particularly limited, but is preferably 0.01 to 10 μm, and more preferably 0.1 to 5 μm.

[0082] From the viewpoint of using the optical laminate of the present invention as a circular polarizer, it is preferable that it further includes a polarizer.

[0083] [Polarizer] The polarizer is not particularly limited as long as it is a material that has the function of converting light into a specific linear polarization, and conventionally known absorptive polarizers and reflective polarizers can be used. Absorbent polarizers include iodine-based polarizers, dye-based polarizers using dichroic dyes, and polyene-based polarizers. Iodine-based polarizers and dye-based polarizers include coated polarizers and stretched polarizers, both of which can be applied, but polarizers made by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and stretching are preferred. Furthermore, as a method of obtaining a polarizer by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate, examples include Japanese Patent No. 5048120, Japanese Patent No. 5143918, Japanese Patent No. 4691205, Japanese Patent No. 4751481, and Japanese Patent No. 4751486, and these known technologies related to polarizers can also be preferably used. Reflective polarizers include polarizers made by laminating thin films with different birefringences, wire grid polarizers, and polarizers combining cholesteric liquid crystals with a selective reflection range and quarter-wave plates. Among these, polyvinyl alcohol-based resin (-CH) is particularly used due to its superior adhesion. ２ A polymer containing -CHOH- as a repeating unit. In particular, a polarizer containing at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymer is preferred.

[0084] In the present invention, the thickness of the polarizer is not particularly limited, but is preferably 5 to 40 μm, more preferably 5 to 30 μm, and even more preferably 5 to 20 μm. With the above thickness, it is possible to make the display device thinner.

[0085] [Image Display Device] The image display device of the present invention is an image display device having the optical laminate of the present invention (particularly an optical laminate having a polarizer). The display element used in the image display device is not particularly limited and examples include liquid crystal cells, organic electroluminescence (hereinafter abbreviated as "EL (Electro Luminescence)") display panels, and plasma display panels. Of these, liquid crystal cells and organic EL display panels are preferred, and organic EL display panels are more preferred. That is, as an image display device, a liquid crystal display device using a liquid crystal cell as a display element, or an organic EL display device using an organic EL display panel as a display element is preferred, and an organic EL display device is more preferred.

[0086] [Organic EL Display Device] An example of an organic EL display device, which is an image display device, is an embodiment in which, from the viewing side, the optical laminate of the present invention (particularly an optical laminate having a polarizer) and an organic EL display panel are arranged in this order. The organic EL display panel is a display panel constructed using an organic EL element in which an organic light-emitting layer (organic electroluminescent layer) is sandwiched between electrodes (between the cathode and the anode). The configuration of the organic EL display panel is not particularly limited, and known configurations can be adopted.

[0087] The present invention will be described in more detail below based on examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the examples shown below.

[0088] [Example 1] [Preparation of the first phase difference film B1] <Formation of photo-alignment film A1> A photo-alignment film composition A1 was prepared by adding the following polymer A (12.0 parts by mass) and the following thermal acid generator A (0.6 parts by mass) to a mixture containing butyl acetate (74 parts by mass) and methyl ethyl ketone (18 parts by mass).

[0089] Polymer A [Weight-average molecular weight: 40,000; the values ​​in the following formula indicate the content (mass%) of each repeating unit relative to the total repeating units in the polymer.]

[0090] Thermal acid generator A

[0091] The prepared photo-alignment film composition A1 was applied to a cellulose polymer film (TG40, manufactured by Fujifilm Corporation) using a #3.0 wire bar, and dried on an 80°C hot plate for 5 minutes to remove the solvent, forming a photoisomerized composition layer with a thickness of 0.5 μm. UV light (ultra-high pressure mercury lamp; UL750; manufactured by HOYA) passed through a wire grid polarizer was applied to the obtained photoisomerized composition layer at a rate of 7.9 mJ / cm². ２ Irradiated with a wavelength of 313 nm to form a photo-aligned film A1 with a thickness of 0.5 μm.

[0092] <Formation of Phase Difference Film B1> Polymerizable liquid crystal composition B1 with the following composition was prepared. --------------------------------------------------- Polymerizable liquid crystal composition B1 --------------------------------------------------- ・The following rod-shaped liquid crystal compound A 45.4 parts by mass ・The following rod-shaped liquid crystal compound B 21.8 parts by mass ・The following rod-shaped liquid crystal compound C 20.0 parts by mass ・The following rod-shaped liquid crystal compound D 7.8 parts by mass ・The following rod-shaped liquid crystal compound E 5.0 parts by mass ・The following photopolymerization initiator A 0.5 parts by mass ・The following leveling agent A 0.06 parts by mass ・Cyclopentanone 179 parts by mass ・Methyl ethyl ketone 54 parts by mass ---------------------------------------------------

[0093] Rod-shaped liquid crystal compound A

[0094] Rod-shaped liquid crystal compound B

[0095] Rod-shaped liquid crystal compound C

[0096] Mixture D of rod-shaped liquid crystal compounds [a mixture of the following liquid crystal compounds (RA), (RB), and (RC) in a mass ratio of 83:15:2]

[0097] Rod-shaped liquid crystal compound E [In the following formula, Me represents a methyl group.]

[0098] Photopolymerization initiator A

[0099] Leveling agent A [In the following formula, a to c represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer, where a:b:c = 56:36:8. The weight-average molecular weight was 18000.]

[0100] The prepared polymerizable liquid crystal composition B1 was coated onto the fabricated photoalignment film A1 using a #6.8 wire bar to form a composition layer. The formed composition layer was heated to 120°C on a hot plate, then cooled to 60°C to stabilize the alignment. Subsequently, the film temperature was maintained at 60°C and the first ultraviolet irradiation (80 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ After that, maintain the film temperature at 120°C and perform a second UV irradiation (300 mJ / cm²). ２ The orientation was fixed by ) and a first phase difference film B1 with a thickness of 3.0 μm was formed. The phase difference film B1 was a positive A plate. The in-plane retardation Re(550) of the phase difference film B1 at a wavelength of 550 nm was 141 nm, and the angle of the in-plane slow axis with respect to the film width direction was 45°. The above angle is expressed as a counterclockwise direction being a positive value when the phase difference film B1 placed on the cellulose polymer film is observed from the phase difference film B1 side, with the film width direction being the reference (0°).

[0101] [Preparation of the second phase difference film C1] <Formation of orientation film A2> An orientation film A2 with the following composition was applied to a 38 μm thick, untreated biaxially oriented polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: Cosmoshine A4100), dried, and cured by ultraviolet irradiation to form an orientation film A2 with a thickness of 2 μm.

[0102] ---------------------------------------------------------------------------- Composition A2 for Orientation Films ---------------------------------------------------------------------------- • The following mixture of polyfunctional (meth)acrylate compounds: 75.0 parts by mass (Dipentaerythritol hexaacrylate: Trimethylolpropane triacrylate: 1,6-Hexanediol diacrylate: Tricyclodecanedimethanol diacrylate = 30:30:25:15) • Tetrafunctional thiol compound (see below): 25.0 parts by mass (3-mercaptobutanoic acid ester of pentaerythritol) • The following initiator: 5.0 parts by mass (Irgacure 907 (manufactured by IGM Resins B.V.)) • The following leveling agent: 0.1 parts by mass (Futergent 602A (manufactured by Neos)) • The following mixed solvent: 420 parts by mass (Mixed solvent of methyl ethyl ketone and methyl isobutyl ketone in a 4:1 ratio) -------------------------------------------------------------------

[0103] Next, a polymerizable liquid crystal composition C1 having the following composition was applied to the alignment film A2 to form a composition layer. After drying the formed composition layer on a hot plate to 70°C, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C1 with a thickness of 1 μm was formed. The phase difference film C1 was a positive C plate. The Rth(550) of the phase difference film C1 at a wavelength of 550 nm was -80 nm.

[0104] ------------------------------------------------------------------- Polymerizable liquid crystal composition C1 ------------------------------------------------------------------- ・31.6 parts by mass of the following rod-shaped liquid crystal compound F ・26.3 parts by mass of the following rod-shaped liquid crystal compound G ・42.1 parts by mass of the following rod-shaped liquid crystal compound H ・5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) ・0.3 parts by mass of the following leveling agent B ・595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0105] Rod-shaped liquid crystal compound F

[0106] Rod-shaped liquid crystal compound G

[0107] Rod-shaped liquid crystal compound H

[0108] Leveling agent B [In the following formula, a to d are a:b:c:d = 70:23:6:1, and represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer. The weight-average molecular weight was 13500.]

[0109] [Fabrication of Polarizing Plate with Phase Difference Film] A polarizer with a protective film was fabricated using the method described in Example 4 of Japanese Patent Publication No. 2021-015294, consisting of a norbornene-based resin film with a hard coat layer formed on one surface, a polarizer, and a TAC (triacetylcellulose) film. The surface of the first phase difference film B1 was subjected to a discharge rate of 125 W・min / m ２The polarizer was subjected to corona treatment, and the corona-treated surface of the phase difference film B1 and the TAC film side of the protective film-equipped polarizer prepared above were bonded together via the adhesive layer B described in Example 4 of Japanese Patent Application Publication No. 2021-015294, such that the angle between the absorption axis of the polarizer and the in-plane slow phase axis of the phase difference film B1 was 45°. Subsequently, the cellulose polymer film and the photo-alignment film A1 were peeled off at the interface with the phase difference film B1 to obtain a polarizer with a phase difference film [layer structure: norbornene-based resin film / polarizer / TAC (triacetylcellulose) film / adhesive layer B / phase difference film B1].

[0110] [Preparation of UV Adhesive 1] UV Adhesive 1 was prepared with the following composition: --------------------------------------------------- UV Adhesive 1 --------------------------------------------------- ・CEL2021P (manufactured by Daicel Corporation) 70 parts by mass ・Rikaresin DME-100 (manufactured by Shin Nippon Rika Co., Ltd.) 20 parts by mass ・2-Ethylhexylglycidyl ether 10 parts by mass ・Polymerization initiator (see below CPI-100P) 4.5 parts by mass ---------------------------------------------------

[0111] CPI-100P

[0112] [Fabrication of optical laminate] The surface of the second phase difference film C1 is discharged at a discharge rate of 125 W・min / m ２ Corona treatment was performed. Next, the phase difference film B1 side of the polarizing plate with phase difference film and the corona-treated surface of the phase difference film C1 were bonded together via the UV adhesive 1 (referred to as "UV adhesive layer 1" after curing). From the phase difference film C1 side, 150 mJ / cm at a wavelength of 365 nm was applied. ２After irradiating the coating with ultraviolet light, the polyethylene terephthalate film was peeled off at the interface with the alignment film A2 to obtain an optical laminate [layer structure: norbornene-based resin film / polarizer / TAC (triacetylcellulose) film / adhesive layer B / phase difference film B1 / UV adhesive layer 1 / phase difference film C1 / alignment film A2]. It was confirmed that in the phase difference film C1 of the optical laminate, the cured product of leveling agent B was unevenly distributed on the surface on the UV adhesive layer side. Furthermore, the penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in UV adhesive 1 into the phase difference film C1 was 200 nm. In the layer structure of the optical laminate shown in Table 1 below, phase difference film B1 and others are abbreviated as "phase difference B1", and the norbornene-based resin film and TAC (triacetylcellulose) film are omitted from the layer structure.

[0113] [Example 2] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C2 prepared by the method described below. It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C2 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C2 was 185 nm.

[0114] [Preparation of the second phase difference film C2] A polymerizable liquid crystal composition C2 having the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 vol ppm) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C2 with a thickness of 1 μm was formed. The phase difference film C2 was a positive C plate. The Rth(550) of the phase difference film C2 at a wavelength of 550 nm was -80 nm.

[0115] ------------------------------------------------------------------- Polymerizable liquid crystal composition C2 ------------------------------------------------------------------- - 31.6 parts by mass of the above rod-shaped liquid crystal compound F - 26.3 parts by mass of the above rod-shaped liquid crystal compound G - 42.1 parts by mass of the above rod-shaped liquid crystal compound H - 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) - 0.9 parts by mass of the above leveling agent B - 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0116] [Example 3] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C3 prepared by the method described below. It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C3 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C3 was 140 nm.

[0117] [Preparation of the second phase difference film C3] A polymerizable liquid crystal composition C1 having the above composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 70°C and ultraviolet irradiation (300 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C3 with a thickness of 1 μm was formed. The phase difference film C3 was a positive C plate. The Rth(550) of the phase difference film C3 at a wavelength of 550 nm was -80 nm.

[0118] [Example 4] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C4 prepared by the method described below. It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C4 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C4 was 105 nm.

[0119] [Preparation of the second phase difference film C4] A polymerizable liquid crystal composition C4 having the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C4 with a thickness of 1 μm was formed. The phase difference film C4 was a positive C plate. The Rth(550) of the phase difference film C4 at a wavelength of 550 nm was -80 nm.

[0120] -------------------------------------------------- Polymerizable liquid crystal composition C4 -------------------------------------------------- ・The above rod-shaped liquid crystal compound F 85.0 parts by mass ・The above rod-shaped liquid crystal compound G 5.8 parts by mass ・The above rod-shaped liquid crystal compound H 9.2 parts by mass ・Initiator 5.0 parts by mass (Irgacure 907 (manufactured by IGM Resins B.V.)) ・The above leveling agent B 0.3 parts by mass ・Mixed solvent 595 parts by mass (Mixed solvent of methyl ethyl ketone:cyclohexanone = 6:4) --------------------------------------------------

[0121] [Example 5] An optical laminate was fabricated in the same manner as in Example 1, except that UV adhesive 1 was replaced with UV adhesive 2 (referred to as "UV adhesive layer 2" after curing). It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C1 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in UV adhesive 2 into the phase difference film C1 was 160 nm.

[0122] [Preparation of UV Adhesive 2] UV Adhesive 2 was prepared with the following composition: --------------------------------------------------- UV Adhesive 2 --------------------------------------------------- ・CEL2021P (manufactured by Daicel Corporation) 70 parts by mass ・Rikaresin DME-100 (manufactured by Shin Nippon Rika Co., Ltd.) 25 parts by mass ・2-Ethylhexylglycidyl ether 5 parts by mass ・Polymerization initiator (CPI-100P above) 4.5 parts by mass ---------------------------------------------------

[0123] [Example 6] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C5 prepared by the method described below. It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C5 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C5 was 300 nm.

[0124] [Preparation of the second phase difference film C5] A polymerizable liquid crystal composition C5 having the following composition was applied to the alignment film A2, which was prepared in the same manner as in Example 1, to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 50°C and ultraviolet irradiation (50 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 vol ppm) using an ultra-high pressure mercury lamp. ２The orientation was fixed by ) and a second phase difference film C5 with a thickness of 1 μm was formed. The phase difference film C5 was a positive C plate. The Rth(550) of the phase difference film C5 at a wavelength of 550 nm was -80 nm.

[0125] ------------------------------------------------------------------- Polymerizable liquid crystal composition C5 ------------------------------------------------------------------- • 20.0 parts by mass of the above rod-shaped liquid crystal compound F • 30.8 parts by mass of the above rod-shaped liquid crystal compound G • 49.2 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.05 parts by mass of the above leveling agent B • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0126] [Example 7] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C6 prepared by the method described below, and the method for fabricating the optical laminate was changed as described below.

[0127] [Preparation of the second phase difference film C6] A polymerizable liquid crystal composition C6 with the following composition was applied to a cellulose polymer film (TG40, manufactured by Fujifilm Corporation) to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 70°C and ultraviolet irradiation (120 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C6 with a thickness of 1 μm was formed. The phase difference film C6 was a positive C plate. The Rth(550) of the phase difference film C6 at a wavelength of 550 nm was -80 nm.

[0128] ------------------------------------------------------------------- Polymerizable liquid crystal composition C6 ------------------------------------------------------------------- ・100.0 parts by mass of the above rod-shaped liquid crystal compound D ・5.0 parts by mass of acrylate monomer (UA-306I, manufactured by Kyoei Chemical Co., Ltd.) ・1.2 parts by mass of the following polymer A ・1.14 parts by mass of the following compound A ・4.0 parts by mass of initiator (Irgacure OXE01 (manufactured by BASF Japan)) ・0.3 parts by mass of the above leveling agent B ・493 parts by mass of methyl isobutyl ketone ・95 parts by mass of ethyl propionate ・43 parts by mass of methyl ethyl ketone -----------------------------------------------------------------------------------

[0129] Polymer A [The numerical values ​​in the following formula indicate the content (mass%) of each repeating unit relative to the total number of repeating units in the polymer. The weight-average molecular weight was 57,000.]

[0130] Compound A

[0131] [Fabrication of optical laminate] The surface of the second phase difference film C6 described above is discharged at a discharge rate of 125 W・min / m ２ Corona treatment was performed. Next, the phase difference film B1 side of the polarizing plate with the phase difference film prepared above and the corona-treated surface of the phase difference film C6 were bonded together via the UV adhesive 1. From the phase difference film C6 side, 150 mJ / cm at a wavelength of 365 nm was applied. ２After irradiating the coating with ultraviolet light, the cellulose polymer film was peeled off at the interface with the phase difference film C6 to obtain an optical laminate [layer structure: norbornene resin film / polarizer / TAC (triacetylcellulose) film / adhesive layer B / phase difference film B1 / UV adhesive layer 1 / phase difference film C6]. It was confirmed that in the phase difference film C6 of the optical laminate, the cured product of leveling agent B was unevenly distributed on the surface on the UV adhesive layer side. Furthermore, the penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in UV adhesive 1 into the phase difference film C6 was 65 nm.

[0132] [Example 8] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C7 prepared by the method described below. It was confirmed that the cured product of the leveling agent C was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C7 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C7 was 200 nm.

[0133] [Preparation of the second phase difference film C7] A polymerizable liquid crystal composition C7 having the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C7 with a thickness of 1 μm was formed. The phase difference film C7 was a positive C plate. The Rth(550) of the phase difference film C7 at a wavelength of 550 nm was -80 nm.

[0134] ------------------------------------------------------------------- Polymerizable liquid crystal composition C7 ------------------------------------------------------------------- • 31.6 parts by mass of the above rod-shaped liquid crystal compound F • 26.3 parts by mass of the above rod-shaped liquid crystal compound G • 42.1 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.3 parts by mass of the following leveling agent C • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0135] Leveling agent C [In the following formula, a to d are a:b:c:d = 71:16:8:5, and represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer. The weight-average molecular weight was 23,000.]

[0136] [Example 9] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C8 prepared by the method described below. It was confirmed that the cured product of the leveling agent D was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C8 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C8 was 200 nm.

[0137] [Preparation of the second phase difference film C8] A polymerizable liquid crystal composition C8 having the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２The orientation was fixed by ) and a second phase difference film C8 with a thickness of 1 μm was formed. The phase difference film C8 was a positive C plate. The Rth(550) of the phase difference film C8 at a wavelength of 550 nm was -80 nm.

[0138] ------------------------------------------------------------------- Polymerizable liquid crystal composition C8 ------------------------------------------------------------------- • 31.6 parts by mass of the above rod-shaped liquid crystal compound F • 26.3 parts by mass of the above rod-shaped liquid crystal compound G • 42.1 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.3 parts by mass of the following leveling agent D • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0139] Leveling agent D [In the following formula, a to d represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer, where a:b:c = 70:24:6. The weight-average molecular weight was 15,000.]

[0140] [Example 10] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C9 prepared by the method described below. It was confirmed that the leveling agent E was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C9 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C9 was 200 nm.

[0141] [Preparation of the second phase difference film C9] A polymerizable liquid crystal composition C9 with the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C9 with a thickness of 1 μm was formed. The phase difference film C9 was a positive C plate. The Rth(550) of the phase difference film C9 at a wavelength of 550 nm was -80 nm.

[0142] ------------------------------------------------------------------- Polymerizable liquid crystal composition C9 ------------------------------------------------------------------- • 31.6 parts by mass of the above rod-shaped liquid crystal compound F • 26.3 parts by mass of the above rod-shaped liquid crystal compound G • 42.1 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.3 parts by mass of the following leveling agent E • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0143] Leveling agent E [In the following formula, a to b are a:b = 70:30, and represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer. The weight-average molecular weight was 18600.]

[0144] [Example 11] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C10 prepared by the method described below. It was confirmed that the cured product of the leveling agent F was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C10 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C10 was 200 nm.

[0145] [Preparation of the second phase difference film C10] A polymerizable liquid crystal composition C10 with the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C10 with a thickness of 1 μm was formed. The phase difference film C10 was a positive C plate. The Rth(550) of the phase difference film C10 at a wavelength of 550 nm was -80 nm.

[0146] ------------------------------------------------------------------- Polymerizable liquid crystal composition C10 ------------------------------------------------------------------- • 31.6 parts by mass of the above rod-shaped liquid crystal compound F • 26.3 parts by mass of the above rod-shaped liquid crystal compound G • 42.1 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.3 parts by mass of the following leveling agent F • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0147] Leveling agent F [In the following formula, a to d are a:b:c:d = 70:27:2:1, and represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer. The weight-average molecular weight was 15,000.]

[0148] [Example 12] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C11 prepared by the method described below. It was confirmed that the cured product of the leveling agent G was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C11 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C11 was 200 nm.

[0149] [Preparation of the second phase difference film C11] A polymerizable liquid crystal composition C11 with the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ( ), and a second phase difference film C11 with a thickness of 1 μm was formed. The phase difference film C11 was a positive C plate. The Rth(550) of the phase difference film C11 at a wavelength of 550 nm was -80 nm.

[0150] ------------------------------------------------------------------- Polymerizable liquid crystal composition C11 ------------------------------------------------------------------- • 31.6 parts by mass of the above rod-shaped liquid crystal compound F • 26.3 parts by mass of the above rod-shaped liquid crystal compound G • 42.1 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.3 parts by mass of the following leveling agent G • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0151] Leveling agent G [In the following formula, a to c represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer, where a:b:c = 70:24:6. The weight-average molecular weight was 15,000.]

[0152] [Example 13] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C12 prepared by the method described below. It was confirmed that the cured product of the leveling agent H was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C12 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C12 was 200 nm.

[0153] [Preparation of the second phase difference film C12] A polymerizable liquid crystal composition C12 having the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２The orientation was fixed by ) and a second phase difference film C12 with a thickness of 1 μm was formed. The phase difference film C12 was a positive C plate. The Rth(550) of the phase difference film C12 at a wavelength of 550 nm was -80 nm.

[0154] ------------------------------------------------------------------- Polymerizable liquid crystal composition C12 ------------------------------------------------------------------- • 31.6 parts by mass of the above rod-shaped liquid crystal compound F • 26.3 parts by mass of the above rod-shaped liquid crystal compound G • 42.1 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.3 parts by mass of the following leveling agent H • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0155] Leveling agent H [In the following formula, a to c represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer, where a:b:c:d = 70:23:6:1. The weight-average molecular weight was 15,000.]

[0156] [Example 14] An optical laminate was fabricated in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C13 prepared by the method described below. It was confirmed that the cured product of the leveling agent I was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C13 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C13 was 225 nm.

[0157] [Preparation of the second phase difference film C13] A polymerizable liquid crystal composition C13 with the following composition was applied to the alignment film A2 prepared in the same manner as in Example 1 to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 60°C and ultraviolet irradiation (100 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C13 with a thickness of 1 μm was formed. The phase difference film C13 was a positive C plate. The Rth(550) of the phase difference film C13 at a wavelength of 550 nm was -80 nm.

[0158] ------------------------------------------------------------------- Polymerizable liquid crystal composition C13 ------------------------------------------------------------------- • 31.6 parts by mass of the above rod-shaped liquid crystal compound F • 26.3 parts by mass of the above rod-shaped liquid crystal compound G • 42.1 parts by mass of the above rod-shaped liquid crystal compound H • 5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) • 0.3 parts by mass of the following leveling agent I • 595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0159] Leveling agent I [In the following formula, a to c represent the content (mass%) of each repeating unit relative to the total repeating units in the polymer, where a:b:c:d = 25:68:6:1. The weight-average molecular weight was 15000.]

[0160] [Example 15] An optical laminate was fabricated in the same manner as in Example 1, except that UV adhesive 1 was replaced with UV adhesive 3 (referred to as "UV adhesive layer 3" after curing). It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C1 in the optical laminate. The penetration thickness of the polymerization initiator (Irgacure 907) and initiator decomposition products contained in UV adhesive 3 into the phase difference film C1 was 250 nm.

[0161] [Preparation of UV Adhesive 3] UV Adhesive 3 was prepared with the following composition: --------------------------------------------------- UV Adhesive 3 --------------------------------------------------- ・Arronix M-220 (manufactured by Toagosei Co., Ltd.) 20 parts by mass ・N-(2-hydroxyethyl)acrylamide 40 parts by mass ・4-acryloylmorpholine 40 parts by mass ・Initiator 1.5 parts by mass (Irgacure 907 (manufactured by IGM Resins B.V.)) ---------------------------------------------------

[0162] [Example 16] An optical laminate was fabricated in the same manner as in Example 1, except that the method for fabricating the optical laminate was changed as follows.

[0163] [Fabrication of Optical Laminates] The surfaces of the first phase difference film B1 and the second phase difference film C1 prepared above are discharged at a discharge rate of 125 W・min / m ２ Corona treatment was performed. Next, the corona-treated surface of phase difference film B1 and the corona-treated surface of phase difference film C1 were bonded together via the UV adhesive 1. From the phase difference film C1 side, 150 mJ / cm was applied at a wavelength of 365 nm. ２After irradiating the coating with ultraviolet light, the cellulose polymer film and the photo-alignment film A1 were peeled off at the interface with the phase difference film B1 to obtain a phase difference film laminate. A polarizer with a protective film was prepared by the method described in Example 4 of Japanese Patent Application Publication No. 2021-015294, consisting of a norbornene resin film / polarizer / TAC (triacetylcellulose) film with a hard coat layer formed on one surface. The phase difference film B1 side of the phase difference film laminate prepared above and the TAC film side of the protective film-attached polarizer prepared above were bonded together via the adhesive layer B described in Example 4 of Japanese Patent Application Publication No. 2021-015294, such that the angle between the absorption axis of the polarizer and the in-plane slow phase axis of the phase difference film B1 was 45°. Then, the polyethylene terephthalate film was peeled off at the interface with the alignment film A2 to obtain an optical laminate [layer structure: norbornene-based resin film / polarizer / TAC (triacetylcellulose) film / adhesive layer B / phase difference film B1 / UV adhesive layer 1 / phase difference film C1 / alignment film A2]. It was confirmed that in the phase difference film B1 and phase difference film C1 of the optical laminate, the cured products of leveling agent A and leveling agent B were unevenly distributed on the surface on the UV adhesive layer side. Furthermore, the penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in UV adhesive 1 into phase difference film B1 was 80 nm, and the penetration thickness into phase difference film C1 was 200 nm.

[0164] [Example 17] An optical laminate was fabricated in the same manner as in Example 1, except that the method for fabricating the polarizing plate with phase difference film was changed as follows. It was confirmed that the cured products of leveling agent A and leveling agent B were unevenly distributed on the surface of the UV adhesive layer side of phase difference film B1 and phase difference film C1 in the optical laminate. In addition, the penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in UV adhesive 1 into phase difference film B1 was 80 nm, and the penetration thickness into phase difference film C1 was 200 nm.

[0165] [Preparation of Polarizing Plate with Phase Difference Film] A polarizer with a protective film was prepared by the method described in Example 4 of Japanese Patent Publication No. 2021-015294, consisting of a norbornene-based resin film with a hard coat layer formed on one surface, a polarizer, and a TAC (triacetylcellulose) film. The surface of the first phase difference film B1 prepared above was subjected to a discharge rate of 125 W・min / m ２ The polarizer was corona-treated, and the corona-treated surface of the phase difference film B1 and the TAC film side of the protective film-attached polarizer prepared above were bonded together via the UV adhesive 1 such that the angle between the absorption axis of the polarizer and the in-plane slow phase axis of the phase difference film B1 was 45°. From the phase difference film B1 side, 150 mJ / cm² was applied at a wavelength of 365 nm. ２ After irradiating the coating with ultraviolet light, the cellulose polymer film and the photo-alignment film A1 were peeled off at the interface with the phase difference film B1 to obtain a polarizing plate with a phase difference film.

[0166] [Example 18] An optical laminate was fabricated in the same manner as in Example 1, except that the method for fabricating the optical laminate was changed as follows.

[0167] [Fabrication of Optical Laminate] A polarizer with a protective film was fabricated using the method described in Example 4 of Japanese Patent Publication No. 2021-015294, consisting of a norbornene-based resin film with a hard coat layer formed on one surface, a polarizer, and a TAC (triacetylcellulose) film. The surface of the first phase difference film B1 fabricated above was subjected to a discharge rate of 125 W・min / m ２ The polarizer was corona-treated, and the corona-treated surface of the phase difference film B1 and the TAC film side of the protective film-attached polarizer prepared above were bonded together via the UV adhesive 1 such that the angle between the absorption axis of the polarizer and the in-plane slow phase axis of the phase difference film B1 was 45°. From the phase difference film B1 side, 150 mJ / cm² was applied at a wavelength of 365 nm. ２After irradiating the coating with ultraviolet light, the cellulose polymer film and photo-alignment film A1 were peeled off at the interface with the phase difference film B1 to obtain an optical laminate [layer structure: norbornene resin film / polarizer / TAC (triacetylcellulose) film / UV adhesive layer 1 / phase difference film B1]. It was confirmed that in the phase difference film B1 of the optical laminate, the cured product of leveling agent A was unevenly distributed on the surface on the UV adhesive layer side. Furthermore, the penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in UV adhesive 1 into the phase difference film B1 was 80 nm.

[0168] [Example 19] An optical laminate was fabricated in the same manner as in Example 1, except that the method for fabricating the optical laminate was changed as follows.

[0169] [Fabrication of Optical Laminate] A polarizer with a protective film was fabricated using the method described in Example 4 of Japanese Patent Publication No. 2021-015294, consisting of a norbornene-based resin film with a hard coat layer formed on one surface, a polarizer, and a TAC (triacetylcellulose) film. The surface of the second phase difference film C1 fabricated above was subjected to a discharge rate of 125 W・min / m ２ The surface of the phase difference film C1 was corona-treated, and the corona-treated surface of the phase difference film C1 and the TAC film side of the protective film polarizer prepared above were bonded together via the UV adhesive 1. From the phase difference film C1 side, 150 mJ / cm² was applied at a wavelength of 365 nm. ２ After irradiating the coating with ultraviolet light, the polyethylene terephthalate film was peeled off at the interface with the alignment film A2 to form an optical laminate [layer structure: norbornene-based resin film / polarizer / TAC (triacetylcellulose) film / UV adhesive layer 1 / phase difference film C1 / alignment film A2]. It was confirmed that in the phase difference film C1 of the optical laminate, the cured product of leveling agent B was unevenly distributed on the surface on the UV adhesive layer side. Furthermore, the penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in UV adhesive 1 into the phase difference film C1 was 200 nm.

[0170] [Example 20] An optical laminate was fabricated in the same manner as in Example 1, except that the first phase difference film B1 was replaced with a phase difference film B2 prepared by the method described below. It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C1 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C1 was 200 nm.

[0171] [Preparation of the first phase difference film B2] A polymerizable liquid crystal composition B2 with the following composition was prepared. ------------------------------------------------------------------- Polymerizable liquid crystal composition B2 ------------------------------------------------------------------- ・The following rod-shaped liquid crystal compound I 14.0 parts by mass ・The following rod-shaped liquid crystal compound J 83.0 parts by mass ・The following rod-shaped liquid crystal compound K 3.0 parts by mass ・The above photopolymerization initiator A 0.5 parts by mass ・The above leveling agent A 0.09 parts by mass ・N-methyl-2-pyrrolidone 669 parts by mass -------------------------------------------------------------------

[0172] Rod-shaped liquid crystal compound I

[0173] Rod-shaped liquid crystal compound J

[0174] Rod-shaped liquid crystal compound K

[0175] A photo-alignment film A1, prepared in the same manner as in Example 1, was coated with the prepared polymerizable liquid crystal composition B2 using a #12 wire bar to form a composition layer. The formed composition layer was heated to 120°C on a hot plate and then cooled to 60°C to stabilize the alignment. Subsequently, under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp, the film temperature was maintained at 60°C and the first ultraviolet irradiation (80 mJ / cm²) was performed. ２ After that, maintain the film temperature at 120°C and perform a second UV irradiation (300 mJ / cm²).２ The orientation was fixed by ) and a first phase difference film B2 with a thickness of 2.4 μm was formed. The phase difference film B2 was a positive A plate. The in-plane retardation Re(550) of the phase difference film B2 at a wavelength of 550 nm was 141 nm, and the angle of the in-plane slow axis with respect to the film width direction was 45°. The above angle is expressed as a counterclockwise direction being a positive value when the phase difference film B2 placed on the cellulose polymer film is observed from the phase difference film B2 side, with the film width direction as the reference (0°).

[0176] [Example 21] An optical laminate was fabricated in the same manner as in Example 1, except that the first phase difference film B1 was replaced with a phase difference film B3 prepared by the method described below. It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C1 in the optical laminate. The penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 1 into the phase difference film C1 was 200 nm.

[0177] [Preparation of the first phase difference film B3] A first phase difference film B3 (thickness: 44 μm) was prepared according to the same procedure as in Example 5 of Japanese Patent Application Publication No. 2015-212368. The first phase difference film B3 was a positive A plate. The angle of the in-plane slow axis with respect to the film width direction was 45°. The above angle is the angle expressed as a counterclockwise direction being a positive value when the first phase difference film B3 was observed, with the film width direction being the reference (0°).

[0178] [Comparative Example 1] An optical laminate was prepared in the same manner as in Example 1, except that the second phase difference film C1 was replaced with a phase difference film C14 prepared by the method described below, and the UV adhesive 1 was replaced with the UV adhesive 4 (referred to as "UV adhesive layer 4" after curing). It was confirmed that the cured product of the leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C14 in the optical laminate. Furthermore, the penetration thickness of the polymerization initiator (CPI-100P) and initiator decomposition products contained in the UV adhesive 4 into the phase difference film C14 was 25 nm.

[0179] [Preparation of the second phase difference film C14] A polymerizable liquid crystal composition C14 having the following composition was applied to the alignment film A2, which was prepared in the same manner as in Example 1, to form a composition layer. After drying the formed composition layer to 70°C on a hot plate, the film temperature was maintained at 80°C and ultraviolet irradiation (500 mJ / cm²) was performed under a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp. ２ The orientation was fixed by ) and a second phase difference film C14 with a thickness of 1 μm was formed. The phase difference film C14 was a positive C plate. The Rth(550) of the phase difference film C14 at a wavelength of 550 nm was -80 nm.

[0180] ------------------------------------------------------------------- Polymerizable liquid crystal composition C14 ------------------------------------------------------------------- ・100 parts by mass of the above rod-shaped liquid crystal compound F ・5.0 parts by mass of initiator (Irgacure 907 (manufactured by IGM Resins B.V.)) ・0.3 parts by mass of the above leveling agent B ・595 parts by mass of the following mixed solvent (Methyl ethyl ketone:cyclohexanone = 6:4 mixed solvent) -----------------------------------------------------------------------------------

[0181] [Preparation of UV Adhesive 4] UV Adhesive 4 was prepared with the following composition: --------------------------------------------------- UV Adhesive 4 --------------------------------------------------- ・CEL2021P (manufactured by Daicel Corporation) 70 parts by mass ・RicaResin DME-100 (manufactured by Shin Nippon Rika Co., Ltd.) 30 parts by mass ・Polymerization initiator (CPI-100P mentioned above) 4.5 parts by mass ---------------------------------------------------

[0182] [Comparative Example 2] An optical laminate was prepared in the same manner as in Comparative Example 1, except that UV adhesive 4 was replaced with UV adhesive 5 (referred to as "UV adhesive layer 5" after curing). It was confirmed that the cured product of leveling agent B was unevenly distributed on the surface of the UV adhesive layer side of the phase difference film C14 in the optical laminate. The penetration thickness of the polymerization initiator (Irgacure 907) and initiator decomposition products contained in UV adhesive 5 into the phase difference film C14 was 25 nm.

[0183] [Preparation of UV Adhesive 5] UV adhesive 5 was prepared with the following composition: --------------------------------------------------- UV Adhesive 5 --------------------------------------------------- ・Arronix M-220 (manufactured by Toagosei Co., Ltd.) 100 parts by mass ・Initiator 1.5 parts by mass (Irgacure 907 (manufactured by IGM Resins B.V.)) ---------------------------------------------------

[0184] [Evaluation] (1) Adhesion Adhesion was evaluated using the cross-cut method described in JIS-K-5600-5-6-1. Specifically, 100 grid squares were made at 1 mm intervals on the surface opposite to the polarizer protective film in the optical laminates prepared in the examples and comparative examples, and an adhesion test was performed using cellophane tape (manufactured by Nichiban Co., Ltd.). The cellophane tape was applied and peeled off three times, and after the third peeling, it was evaluated according to the following evaluation criteria. The grid squares were made by making cuts that reached the inside of the UV adhesive layer. If the evaluation result is any of evaluations A to C, there is no practical problem, and evaluation A is preferred. "A": 90 to 100 squares in the grid squares did not peel off "B": 70 to 89 squares in the grid squares did not peel off "C": 50 to 69 squares in the grid squares did not peel off "D": 49 or fewer squares in the grid squares did not peel off

[0185] (2) Unevenness An optical laminate was placed on a backlight on which one of the above-mentioned polarizers with protective film was placed, such that the polarizer protective film in the optical laminate was on the viewing side, and the angle between the polarizer absorption axis of the optical laminate and the polarizer absorption axis on the backlight was 90°. At an extreme angle of 45°, the visibility was observed in the angle range of azimuth angles from 0 to 360° and evaluated according to the following criteria. A: Almost no unevenness in color or brightness is visible, and it is particularly excellent. B: Unevenness in color or brightness is visible, but it is very slight. C: Unevenness in color or brightness is large and unacceptable.

[0186]

[0187] The results shown in Table 1 indicate that when the penetration thickness of the polymerization initiator or polymerization initiator decomposition product in the phase difference film is less than 30 nm, the adhesion between the phase difference film and the UV adhesive layer is poor (Comparative Examples 1 and 2).

[0188] In contrast, it was found that when silicon-based or alkyl-based leveling agents are unevenly distributed on the adhesive layer side of the phase difference film, and the penetration thickness of the polymerization initiator or polymerization initiator decomposition product in the phase difference film is 30 to 300 nm, the adhesion between the phase difference film and the UV adhesive layer is good (Examples 1 to 21). In particular, a comparison between Example 1 and Example 2 showed that when the ratio of the penetration thickness of the polymerization initiator or polymerization initiator decomposition product to the uneven distribution thickness of the leveling agent in the phase difference film (penetration thickness / uneven distribution thickness) is 2.0 to 50, the adhesion between the phase difference film and the UV adhesive layer is even better. Furthermore, a comparison between Example 1 and Example 3 showed that when the reaction rate of acrylate or methacrylate is 50 to 80%, the adhesion between the phase difference film and the UV adhesive layer is even better. Furthermore, a comparison between Example 1 and Example 4 revealed that when the liquid crystal composition contains 20 to 80% by mass of monofunctional polymerizable liquid crystal compounds relative to the total mass of polymerizable liquid crystal compounds, the adhesion between the phase difference film and the UV adhesive layer is improved. A comparison between Example 1 and Example 5 revealed that when the UV adhesive contains 8 to 80% by mass of polymerizable compounds with a molecular weight of 200 or less relative to the total mass of polymerizable compounds contained in the UV adhesive, the adhesion between the phase difference film and the UV adhesive layer is improved. A comparison between Example 1 and Examples 6 and 14 revealed that when the surface free energy of the adhesive layer side of the phase difference film is 22 to 32 mN / m, color and brightness unevenness is reduced. A comparison between Example 1 and Example 7 revealed that the presence of an alignment film improves the adhesion between the phase difference film and the UV adhesive layer. Furthermore, a comparison of Examples 8 to 13 revealed that when the leveling agent is a polymer having repeating units B containing radical polymerizable groups or cationic polymerizable groups, the adhesion between the phase difference film and the UV adhesive layer is improved. Additionally, when the content of repeating units B is 3 to 50% by mass relative to the total repeating units of the leveling agent (polymer), or when the number of atoms in the side chain of repeating unit B from the atom directly bonded to the main chain to the radical polymerizable group or cationic polymerizable group is 7 or more, the adhesion between the phase difference film and the UV adhesive layer is further improved.

Claims

1. An optical laminate having at least one phase difference film and an adhesive layer formed by curing an ultraviolet-curable adhesive adjacent to each other, wherein the phase difference film is a liquid crystal cured layer formed by fixing the orientation state of a liquid crystal composition comprising a polymerizable liquid crystal compound and a silicon-based or alkyl-based leveling agent, the leveling agent is unevenly distributed on the adhesive layer side of the phase difference film, the ultraviolet-curable adhesive contains a polymerization initiator or a polymerization initiator decomposition product, and the penetration thickness of the polymerization initiator or the polymerization initiator decomposition product in the phase difference film is 30 to 300 nm. Here, the penetration thickness of the polymerization initiator or polymerization initiator decomposition product in the phase difference film is defined as the thickness of the region including the surface of the adhesive layer of the phase difference film, where, when ion beam irradiation is performed on the phase difference film from the adhesive layer side surface toward the surface opposite the adhesive layer, and the secondary ion intensity of the component derived from the polymerization initiator or polymerization initiator decomposition product is measured, the ratio of the secondary ion intensity I of the component derived from the polymerization initiator or polymerization initiator decomposition product in the phase difference film to the average value Imin of the secondary ion intensity of the component derived from the polymerization initiator or polymerization initiator decomposition product in the central region from the adhesive layer side surface of the phase difference film to a depth position corresponding to 48% to 52% of the total thickness of the phase difference film satisfies the following formula (I-1): 2 ≤ I / Imin (I-1) 2. The optical laminate according to claim 1, wherein the ratio of the penetration thickness of the polymerization initiator or the polymerization initiator decomposition product to the thickness of the region in the phase difference film where the leveling agent is unevenly distributed is 2.0 to 50. Here, the thickness of the region in the phase difference film where the leveling agent is unevenly distributed refers to the thickness of the region including the surface of the phase difference film, where, when an ion beam is irradiated from the surface of the phase difference film toward the surface opposite the adhesive layer, a time-of-flight secondary ion mass spectrometry method is performed to measure the secondary ion intensity of the component derived from the leveling agent, and the ratio of the secondary ion intensity L of the component derived from the leveling agent in the phase difference film to the average value Lmin of the secondary ion intensity of the component derived from the leveling agent in the central region from the surface of the phase difference film toward a depth corresponding to 48% to 52% of the total thickness of the phase difference film satisfies the following formula (I-2): 2 ≤ L / Lmin (I-2) 3. The optical laminate according to claim 1, wherein the reaction rate of the acrylate or methacrylate in the phase difference film is 50 to 80%.

4. The optical laminate according to claim 1, wherein the liquid crystal composition contains 20 to 80% by mass of monofunctional polymerizable liquid crystal compounds based on the total mass of polymerizable liquid crystal compounds contained in the liquid crystal composition.

5. The optical laminate according to claim 1, wherein the ultraviolet-curable adhesive contains 8 to 80% by mass of polymerizable compounds with a molecular weight of 200 or less, relative to the total mass of polymerizable compounds contained in the ultraviolet-curable adhesive.

6. The optical laminate according to claim 1, wherein the leveling agent has repeating units A comprising silicon atoms or alkyl groups, and the content of the repeating units A is 30 to 90% by mass relative to the total repeating units of the leveling agent.

7. The optical laminate according to claim 1, wherein the leveling agent has repeating units B comprising radical polymerizable groups or cationic polymerizable groups.

8. The optical laminate according to claim 7, wherein the content of the repeating unit B is 3 to 50% by mass relative to the total repeating units of the leveling agent.

9. The optical laminate according to claim 7, wherein the number of atoms in the side chain of the repeating unit B, from the atom directly bonded to the main chain to the radical polymerizable group or the cationic polymerizable group, is 7 or more.

10. The optical laminate according to claim 1, wherein the surface free energy of the adhesive layer side surface of the phase difference film is 22 to 32 mN / m.

11. The optical laminate according to claim 1, wherein the phase difference film is a positive C plate.

12. The optical laminate according to claim 11, wherein the thickness of the positive C plate is 3 μm or less.

13. The optical laminate according to claim 11, further comprising an alignment film adjacent to the positive C plate.

14. An optical laminate according to any one of claims 1 to 13, further comprising a polarizer.

15. An image display device having the optical laminate described in claim 14.

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