Polarizing plate and organic electroluminescent display device

Abstract

Provided are a polarizing plate and an organic EL display device which have excellent black compactness in the front direction even after an organic EL display device obtained by being affixed to an organic EL display panel is exposed to a high-temperature environment for a long period of time. This polarizing plate is provided with: a polarizer formed using a composition containing a first liquid crystal compound and a dichroic substance; and an optically anisotropic layer disposed adjacent to the polarizer and formed using a composition containing a second liquid crystal compound, in which the dichroic substance content in the polarizer is 40 mass% or less relative to the total mass of the polarizer.

Description

[0001] This application is a divisional application of the invention patent application filed on August 23, 2021, with application number 202180054993.9 and invention title "Polarizer and Organic Electroluminescent Display Device". Technical Field

[0002] This invention relates to a polarizer and an organic electroluminescent display device. Background Technology

[0003] Optical anisotropic layers with phase differences are used in many applications. For example, organic electroluminescent (EL) display devices have structures that use metal electrodes, which sometimes reflect external light, causing problems such as reduced contrast and projection. Therefore, polarizers, which include optical anisotropic layers and polarizers, have been used to suppress the adverse effects caused by external light reflection.

[0004] Patent Document 1 discloses a circular polarizer obtained by attaching a phase difference layer (optical anisotropy layer) to a polarizer formed using a dichroic material via an adhesive layer.

[0005] Previous technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2020-023153 Summary of the Invention

[0006] The technical problem to be solved by the invention On the other hand, in recent years, in order to further improve image quality, excellent black density on the front side is required in OLED display devices. In particular, excellent black density on the front side is required even after the OLED display device has been exposed to high temperatures for a long time. In addition, black density refers to the ability to suppress the coloring of black when displaying black in an image display device, and to have low reflectivity of reflected light.

[0007] The inventors manufactured a circular polarizer disclosed in Patent Document 1, which is formed by bonding a polarizer and an optical anisotropy layer together via an adhesive layer. They evaluated the performance of an organic EL display device obtained by attaching the polarizer to an organic EL display panel and exposing it to a high-temperature environment for a long time. The results showed that the device could not fully meet the above requirements.

[0008] In view of the above, the objective of the present invention is to provide a polarizer that exhibits excellent black density in the front direction even after an organic EL display device obtained by attaching it to an organic EL display panel has been exposed to a high-temperature environment for a long time.

[0009] Furthermore, the subject of this invention is to provide an organic EL display device.

[0010] means for solving technical problems As a result of in-depth research into the problems of the prior art, the inventors discovered that the above-mentioned problems can be solved by the following structure.

[0011] (1) A polarizer having: A polarizer formed using a composition comprising a first liquid crystal compound and a dichroic substance; and An optical anisotropic layer is formed using a composition containing a second liquid crystal compound, arranged adjacent to a polarizer. The content of dichroic material in the polarizer is less than 40% by mass relative to the total mass of the polarizer.

[0012] (2) According to the polarizer described in (1), wherein the content of dichroic material in the polarizer is less than 30% by mass relative to the total mass of the polarizer.

[0013] (3) The polarizer according to (1) or (2), wherein the angle formed by the absorption axis of the polarizer and the in-plane slow axis on the surface of the polarizer side of the optical anisotropic layer is within 1°.

[0014] (4) The polarizer according to any one of (1) to (3), wherein the optical anisotropy layer is a layer formed by fixing a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis.

[0015] (5) The polarizer according to any one of (1) to (4), wherein the optical anisotropy layer has a plurality of layers formed by fixing a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis. The twist angles of the second liquid crystal compound in the multiple layers are different.

[0016] (6) The polarizer according to any one of (1) to (5), wherein the optical anisotropy layer has a plurality of layers formed by fixing a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis. The twist angle of the second liquid crystal compound with multiple layers is in different ratios to the layer thickness.

[0017] (7) The polarizer according to any one of (1) to (6), wherein the optical anisotropy layer has a first optical anisotropy layer and a second optical anisotropy layer, The first optical anisotropy layer is disposed on the polarizer side. The first optical anisotropic layer and the second optical anisotropic layer are layers formed by fixing a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis. The twisting direction of the second liquid crystal compound in the first optical anisotropic layer is the same as the twisting direction of the second liquid crystal compound in the second optical anisotropic layer. The twist angle of the second liquid crystal compound in the first optical anisotropic layer is 26.5 ± 10.0°. The twist angle of the second liquid crystal compound in the second optical anisotropic layer is 78.6 ± 10.0°. The in-plane slow axis on the surface of the first optical anisotropy layer on the second optical anisotropy layer side is parallel to the in-plane slow axis on the surface of the second optical anisotropy layer on the first optical anisotropy layer side. The values ​​of the product of the refractive index anisotropy Δn1 and the thickness d1 of the first optical anisotropy layer, Δn1·d1, measured at a wavelength of 550 nm, and the values ​​of the product of the refractive index anisotropy Δn2 and the thickness d2 of the second optical anisotropy layer, Δn2·d2, measured at a wavelength of 550 nm, satisfy the following equations (1) and (2), respectively.

[0018] Equation (1) 252nm≤Δn1·d1≤312nm Equation (2) 110nm≤Δn2·d2≤170nm (8) The polarizer according to any one of (1) to (7), wherein, when analyzing the composition of the polarizer in the depth direction using time-of-flight secondary ion mass spectrometry, the relationship between the maximum intensity Imax of the secondary ion intensity originating from the dichroic material and the intensity Isur1 of the secondary ion intensity originating from the dichroic material on the surface of the polarizer opposite to the optical anisotropic layer side satisfies equation (3).

[0019] Equation (3) 2.0≤Imax / Isur1 (9) The polarizer according to any one of (1) to (8), wherein the absolute value of the difference between the logP of the second liquid crystal compound and the logP of the dichroic material is 3.0 or more.

[0020] (10) An organic electroluminescent display device having a polarizer as described in any one of (1) to (9).

[0021] Invention Effects According to the present invention, a polarizer is provided that exhibits excellent black density in the front direction even after an organic EL display device obtained by attaching to an organic EL display panel has been exposed to a high-temperature environment for a long time.

[0022] Furthermore, according to the present invention, an organic EL display device can also be provided. Attached Figure Description

[0023] Figure 1This is a schematic cross-sectional view of one embodiment of the polarizer of the present invention.

[0024] Figure 2 This is a schematic diagram illustrating the distribution of secondary ion intensities along the depth direction of each component detected by analyzing the components along the depth direction of a polarizer using time-of-flight secondary ion mass spectrometry (TOF-SIMS).

[0025] Figure 3 This is a schematic cross-sectional view of a preferred embodiment of the polarizer of the present invention.

[0026] Figure 4 This is a diagram showing the relationship between the absorption axis of the polarizer 12 in a preferred embodiment of the polarizer of the present invention and the in-plane slow axes of the first optical anisotropy layer 16 and the second optical anisotropy layer 18.

[0027] Figure 5 It means from Figure 4 A schematic diagram showing the relationship between the absorption axis of polarizer 12 and the angles of the in-plane slow axes of the first optical anisotropic layer 16 and the second optical anisotropic layer 18 when viewed in the direction of the arrow.

[0028] Figure 6 This is a cross-sectional view used to illustrate the composition layer of step 1.

[0029] Figure 7 This is a cross-sectional view used to illustrate the composition layer of step 2.

[0030] Figure 8 This plots the helical torsional power (HTP) (μm) for each of chiral reagents A and B. -1 ) × concentration (mass%) and light irradiation (mJ / cm²) 2 A diagram illustrating the relationship between ).

[0031] Figure 9 It plots the weighted average helical torsional force (μm) in a system using both chiral reagent A and chiral reagent B. -1 ) and light irradiance (mJ / cm 2 A diagram illustrating the relationship between .

[0032] Figure 10 This is a cross-sectional view used to illustrate the composition layer in step 4. Detailed Implementation

[0033] The present invention will now be described in detail. Furthermore, in this specification, the numerical range indicated by "~" represents the range encompassed by the values ​​described before and after "~" as a lower and upper limit. First, the terminology used in this specification will be explained.

[0034] Unless otherwise specified, the in-plane slow axis is defined at 550 nm.

[0035] In this invention, Re(λ) and Rth(λ) represent the in-plane delay and the thickness direction delay at wavelength λ, respectively. Unless otherwise specified, wavelength λ is set to 550 nm.

[0036] In this invention, Re(λ) and Rth(λ) are values ​​obtained by measurement at wavelength λ using an AxoScan (manufactured by Axometrics). They are calculated by inputting the average refractive index ((nx+ny+nz) / 3) and film thickness (d(μm)) into the AxoScan. Slow axis direction (°) Re(λ) = R0(λ) Rth(λ)=((nx+ny) / 2-nz)×d.

[0037] Additionally, R0(λ) is shown as a value calculated using AxoScan, but it represents Re(λ).

[0038] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by ATAGO CO.,LTD.) and a sodium lamp (λ=589nm) as the light source. Furthermore, when measuring wavelength dependence, measurements can be performed using a multi-wavelength Abbe refractometer DR-M2 (manufactured by ATAGO CO.,LTD.) combined with an interference filter.

[0039] Furthermore, values ​​from the Polymer Handbook (JOHN WILEY & SONS, INC) and various optical film catalogs can be used. The average refractive index values ​​of the main optical films are exemplified below: cellulose acylate (1.48), cyclic olefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0040] In this specification, "light" refers to activating light or radiation, such as the bright-line spectrum of a mercury lamp, far-ultraviolet light represented by an excimer laser, extreme ultraviolet (EUV) light, X-rays, ultraviolet light, and electron beams (EB). Among these, ultraviolet light is preferred.

[0041] In this specification, "visible light" refers to light in the range of 380–780 nm. Furthermore, unless otherwise specified, the measurement wavelength is 550 nm.

[0042] Furthermore, in this specification, the angular relationships (e.g., "orthogonal", "parallel", etc.) are included within the range of permissible errors in the technical field to which this invention pertains. Specifically, this means that the error from the strict angle is preferably within ±10°, and more preferably within ±5° or less, and more preferably within ±3° or less.

[0043] The bonding direction of the divalent groups (e.g., -C(O)O-) described in this specification is not particularly limited. For example, if L1 in formula (1) described later is -C(O)O-, the position bonded to the P1 side is set as 1. And set the position of bonding with SP1 side to 2, then L1 can be 1-C(O)-O- 2, can also be 1-OC(O)- 2.

[0044] As a characteristic feature of the polarizer of the present invention, the following features can be cited: the polarizer is in direct contact with the optical anisotropic layer, and the concentration of dichroic material in the polarizer is below a specified value.

[0045] Based on our research into the reasons why the polarizer described in Patent Document 1 failed to achieve the desired effect, we found that, firstly, when an adhesive layer separates the polarizer from the optical anisotropic layer, light reflection easily occurs at the interfaces between the polarizer and the adhesive layer, and between the adhesive layer and the optical anisotropic layer, thus contributing to the deterioration of black density. In particular, since the polarizer contains a dichroic material with a relatively high refractive index, the refractive index of the polarizer itself increases, and the refractive index difference between adjacent adhesive layers increases, making light reflection even more likely.

[0046] In contrast, in this invention, by making the polarizer directly contact the optical anisotropic layer, the reflection of light from the adhesive layer is suppressed, and by setting the concentration of the dichroic material in the polarizer to below a predetermined value, the refractive index of the polarizer is adjusted to be similar to that of the optical anisotropic layer, thereby suppressing the reflection of light at the interface between the polarizer and the optical anisotropic layer.

[0047] The polarizer of the present invention will now be described using the accompanying drawings.

[0048] Figure 1 This is a schematic cross-sectional view of one embodiment of the polarizer of the present invention. The polarizer 10A has a polarizer 12 and an optical anisotropy layer 14. For example... Figure 1 As shown, the polarizer 12 is arranged adjacent to the optical anisotropic layer 14. That is, the polarizer 12 and the optical anisotropic layer 14 are arranged in direct contact.

[0049] In this context, "adjacent" means that the polarizer and the optical anisotropy layer are configured without any other layers such as an adhesive layer between them.

[0050] The arrangement of the polarizer 12 adjacent to the optical anisotropic layer 14 can also be determined using time-of-flight secondary ion mass spectrometry as described below.

[0051] More specifically, while irradiating an ion beam from one surface of the polarizer to the other, the composition in the depth direction of the polarizer is analyzed using time-of-flight secondary ion mass spectrometry to obtain the depth-direction distribution of the secondary ion intensity of the components contained in the polarizer and the secondary ion intensity of the components contained in the optical anisotropic layer.

[0052] exist Figure 2 The diagram shows the composition distribution obtained by sputtering ions from the polarizer-side surface of a polarizer toward the optical anisotropic layer side, and analyzing the composition in the depth direction of each layer using TOF-SIMS. In this specification, the depth direction refers to the direction from the polarizer-side surface of the polarizer toward the optical anisotropic layer side.

[0053] exist Figure 2 In the depth distribution recorded in the document, the horizontal axis ( Figure 2 In the middle, the axis extending left and right along the plane of the paper represents the depth with reference to the surface of the polarizer side of the polarizer, and the vertical axis ( Figure 2 In the figure, the axis extending vertically along the paper represents the secondary ionic strength of each component.

[0054] In addition, regarding the TOF-SIMS method, specifically, it is described in "Secondary Ion Mass Spectrometry" edited by The Japan Society of Vacuum and Surface Science, MARUZEN GROUP (published in 1999).

[0055] In addition, while irradiating the polarizer with an ion beam and analyzing the composition in the depth direction using TOF-SIMS, a series of operations are repeated, after performing composition analysis in the surface depth region of 1 to 2 nm, further mining in the depth direction from 1 nm to several hundred nm and performing composition analysis in the next surface depth region of 1 to 2 nm.

[0056] exist Figure 2 The distribution along the depth direction shows the results of secondary ion intensity originating from the components contained in the polarizer (line C1 in the figure) and the results of secondary ion intensity originating from the components contained in the optical anisotropic layer (line C2 in the figure).

[0057] Furthermore, in this specification, the "secondary ion intensity originating from the components contained in the polarizer" obtained by analyzing the distribution in the depth direction of the polarizer using TOF-SIMS means the intensity of fragment ions originating from the components contained in the polarizer, and the "secondary ion intensity originating from the components contained in the optical anisotropy layer" means the intensity of fragment ions originating from the components contained in the optical anisotropy layer.

[0058] like Figure 2 As shown, if an ion beam is irradiated from the polarizer side of the polarizer towards the optical anisotropic layer while the composition in the depth direction of the polarizer is analyzed using the TOF-SIMS method, a high secondary ion intensity originating from the component contained in the polarizer is initially observed. As the ion beam is further irradiated towards the depth direction, the secondary ion intensity gradually decreases. Conversely, from a certain depth position, the secondary ion intensity originating from the component contained in the optical anisotropic layer gradually increases. After a predetermined depth position, a high secondary ion intensity originating from the component contained in the optical anisotropic layer is observed, but the secondary ion intensity originating from the component contained in the polarizer is not observed.

[0059] When the polarizer is adjacent to the optical anisotropic layer, such as Figure 2 As shown, at a specified depth position P, the distribution (line) representing the intensity of secondary ions originating from the components contained in the polarizer intersects with the distribution (line) representing the intensity of secondary ions originating from the components contained in the optical anisotropy layer. That is, near the interface between the polarizer and the optical anisotropy layer, there exists a depth position where the intensity of secondary ions originating from the components contained in the polarizer and the intensity of secondary ions originating from the components contained in the optical anisotropy layer are equal.

[0060] As a measurement method for the TOF-SIMS method, well-known methods can be cited. For example, the following can be cited as measuring devices and measuring conditions.

[0061] • Device: TOF-SIMS 5 (manufactured by ION-TOF) • Depth-direction analysis: Simultaneous use of Ar ion sputtering • Measurement range: 128 points are scanned by each grating in one direction and its orthogonal directions. • Polarity: posi (positive), nega (negative) Furthermore, when obtaining the aforementioned distribution of secondary ion intensity, the components included in the polarizer are, for example, a dichroic material or a first liquid crystal compound.

[0062] Furthermore, a second liquid crystal compound was selected as a component contained in the optical anisotropy layer.

[0063] The following is a detailed description of the components included in a polarizer.

[0064] <Polarizer> The polarizer is formed using a composition comprising a first liquid crystal compound and a dichroic material (hereinafter also referred to as a polarizer forming composition). In the polarizer, the dichroic material is also oriented in a predetermined direction along with the orientation of the first liquid crystal compound. In particular, the dichroic material is preferably horizontally oriented.

[0065] The materials used to form the polarizer will be described in detail below.

[0066] (First liquid crystal compound) As the first liquid crystal compound, either a high molecular weight liquid crystal compound or a low molecular weight liquid crystal compound can be used. From the viewpoint of achieving a higher degree of orientation of dichroic materials, a high molecular weight liquid crystal compound is preferred.

[0067] "Polymer liquid crystal compound" refers to a liquid crystal compound that has repeating units in its chemical structure.

[0068] Furthermore, "low molecular weight liquid crystal compounds" refer to liquid crystal compounds that do not have repeating units in their chemical structure.

[0069] Examples of polymeric liquid crystal compounds include the thermotropic liquid crystal polymer described in Japanese Patent Application Publication No. 2011-237513 and the polymeric liquid crystal compounds described in paragraphs

[0012] to

[0042] of International Publication No. 2018 / 199096.

[0070] As a low-molecular-weight liquid crystal compound, examples include the liquid crystal compounds described in paragraphs

[0072] to

[0088] of Japanese Patent Application Publication No. 2013-228706, among which, liquid crystal compounds exhibiting smectic properties are preferred.

[0071] Furthermore, as the first liquid crystal compound, both high-molecular-weight liquid crystal compounds and low-molecular-weight liquid crystal compounds can be used simultaneously.

[0072] From the viewpoint that the orientation degree of dichroic materials becomes higher, a polymeric liquid crystal compound containing a repeating unit (hereinafter also simply referred to as "repeating unit (1)") represented by the following formula (1) is preferred as the first liquid crystal compound.

[0073] [Chemical Formula 1] In the above formula (1), P1 represents the main chain of the repeating unit, L1 represents a single bond or a divalent linking group, SP1 represents a spacer group, M1 represents a mesocrystalline group, and T1 represents a terminal group.

[0074] As the main chain of the repeating unit represented by P1, examples include the groups represented by the following formulas (P1-A) to (P1-D), among which, from the viewpoint of the diversity of monomers that can be used as raw materials and ease of processing, the group represented by the following formula (P1-A) is preferred.

[0075] [Chemical Formula 2] In the above formulas (P1-A) to (P1-D) This indicates the bonding position with L1 in the above formula (1).

[0076] In the above formulas (P1-A) to (P1-D), R 1 R 2 R 3 and R 4 Each of the above-mentioned alkyl groups independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. The alkyl group can be a straight-chain or branched alkyl group, or an alkyl group having a cyclic structure (cycloalkyl). Furthermore, the number of carbon atoms in the alkyl group is preferably 1 to 5.

[0077] The group represented by the above formula (P1-A) is preferably a unit of a partial structure of poly(meth)acrylate obtained by polymerization of (meth)acrylate.

[0078] The group represented by the above formula (P1-B) is preferably an ethylene glycol unit formed by ring-opening polymerization of the epoxy group of a compound having an epoxy group.

[0079] The group represented by the above formula (P1-C) is preferably a propylene glycol unit formed by ring-opening polymerization of an oxetane compound having an oxetane.

[0080] The group represented by the above formula (P1-D) is preferably a siloxane unit of a polysiloxane obtained by polycondensation of a compound having at least one of alkoxysilyl and silanol groups. Examples of compounds having at least one of alkoxysilyl and silanol groups include those having the formula SiR. 4 (OR) 5 Compounds containing the group represented by )2-. Where R 4 R in (P1-D) 4 The meanings are the same, multiple R 5 Alkyl groups, which can be independently represented by 1 to 10 hydrogen or carbon atoms respectively.

[0081] In the above formula (1), L1 is a single bond or a divalent linking group.

[0082] Examples of divalent linking groups represented by L1 include -C(O)O-, -O-, -S-, and -C(O)NR. 6 -, -SO2- and -NR 6 R 7 - In the formula, R 6 and R 7 Each can be independently represented by a hydrogen atom or an alkyl group having 1 to 6 carbon atoms that may have substituents.

[0083] When P1 is a group represented by formula (P1-A), from the viewpoint that the orientation degree of dichroic substances becomes higher, L1 is preferably a group represented by -C(O)O-.

[0084] When P1 is a group represented by formulas (P1-B) to (P1-D), from the viewpoint that the orientation degree of dichroic substances becomes higher, L1 is preferably a single bond.

[0085] In the above formula (1), from the viewpoint of easy display of liquid crystal properties and availability of raw materials, the spacer group represented by SP1 preferably includes at least one structure selected from the group consisting of ethylene oxide structure, propylene oxide structure, polysiloxane structure and fluorinated alkylene structure.

[0086] Among them, the oxyethylene structure represented by SP1 is preferably... -(CH2-CH2O) n1 - The group to be represented. In the formula, n1 represents an integer from 1 to 20. This indicates the bonding position with L1 or M1 in the above formula (1). From the viewpoint that the orientation degree of dichroic materials becomes higher, n1 is preferably an integer from 2 to 10, more preferably an integer from 2 to 4, and most preferably 3.

[0087] Furthermore, from the viewpoint that dichroic materials have a higher degree of orientation, the oxopropylidene structure represented by SP1 is preferred. -(CH(CH3)-CH2O) n2 - The group to be represented. In the formula, n2 represents an integer from 1 to 3. Indicates the bonding position with L1 or M1.

[0088] Furthermore, from the viewpoint that dichroic materials have a higher degree of orientation, the polysiloxane structure represented by SP1 is preferred. -(Si(CH3)2-O) n3 - The group to be represented. In the formula, n3 represents an integer from 6 to 10. Indicates the bonding position with L1 or M1.

[0089] Furthermore, from the viewpoint that dichroic materials have a higher degree of orientation, the fluorinated alkylene structure represented by SP1 is preferred. -(CF2-CF2) n4 - The group to be represented. In the formula, n4 represents an integer from 6 to 10. Indicates the bonding position with L1 or M1.

[0090] In the above formula (1), the mesocrystalline group represented by M1 is a group that represents the main framework of liquid crystal molecules that contribute to the formation of liquid crystals. Liquid crystal molecules exhibit liquid crystal properties as an intermediate state (intermediate phase) between the crystalline state and the isotropic liquid state. There are no particular limitations on the mesocrystalline group, for example, one can refer to the description in "Flussige Kristalle in Tabellen II" (VEBDeutsche Verlag fur Grundstoff Industrie, Leipzig, 1990, 2000) (especially Chapter 3).

[0091] As a mesocrystalline group, it is preferably a group having a cyclic structure selected from at least one group having a cyclic structure, including aromatic hydrocarbon groups, heterocyclic groups and alicyclic groups.

[0092] From the viewpoint that the orientation degree of dichroic substances becomes higher, the mesocrystalline group preferably has aromatic hydrocarbon groups, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups.

[0093] From the viewpoints of liquid crystal manifestation, liquid crystal phase transition temperature adjustment, raw material availability and synthetic applicability, and the viewpoint of increasing the orientation degree of dichroic substances, the group represented by the following formula (M1-A) or the following formula (M1-B) is preferred as the mesocrystalline group, and the group represented by formula (M1-B) is more preferred.

[0094] [Chemical Formula 3] In formula (M1-A), A1 is a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. These groups may be substituted with alkyl, fluorinated alkyl, alkoxy, or substituent groups.

[0095] The divalent group represented by A1 is preferably a 4- to 6-membered ring. Furthermore, the divalent group represented by A1 can be a monocyclic ring or a fused ring.

[0096] Examples of divalent aromatic hydrocarbon groups represented by A1 include phenylene, naphthylene, fluorene-diyl, anthracene-diyl, and tetraphenyl-diyl. From the viewpoint of the diversity of mesocrystalline framework design and the availability of raw materials, phenylene or naphthylene is preferred, and phenylene is more preferred.

[0097] The divalent heterocyclic group represented by A1 can be either aromatic or non-aromatic, but from the viewpoint that the orientation degree of dichroic substances becomes higher, a divalent aromatic heterocyclic group is preferred.

[0098] Examples of atoms other than carbon that constitute a divalent aromatic heterocyclic group include nitrogen, sulfur, and oxygen atoms. When an aromatic heterocyclic group has multiple atoms constituting rings other than carbon, these atoms can be the same or different.

[0099] Examples of divalent aromatic heterocyclic groups include pyridinyl (pyridin-diyl), pyridazin-diyl, imidazole-diyl, thiophene (thiophene-diyl), quinolinyl (quinoline-diyl), isoquinolinyl (isoquinoline-diyl), oxazole-diyl, thiazole-diyl, oxadiazole-diyl, benzothiazole-diyl, benzothiadiazole-diyl, phthalimide-diyl, thienothiazole-diyl, thiazonothiazole-diyl, thienothiphene-diyl, and thienooxazole-diyl.

[0100] Examples of divalent alicyclic groups represented by A1 include cyclopentylene and cyclohexylene.

[0101] In formula (M1-A), a1 represents an integer from 1 to 10. When a1 is 2 or higher, multiple A1 values ​​can be the same or different.

[0102] In formula (M1-B), A2 and A3 are each independently a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. Specific examples and preferred embodiments of A2 and A3 are the same as A1 in formula (M1-A), therefore their description is omitted.

[0103] In formula (M1-B), a2 represents an integer from 1 to 10. When a2 is 2 or more, multiple A2s can be the same or different, multiple A3s can be the same or different, and multiple LA1s can be the same or different. From the viewpoint that the orientation degree of dichroic materials becomes higher, a2 is preferably an integer of 2 or more, and more preferably 2.

[0104] In formula (M1-B), when a2 is 1, LA1 is a divalent linking group. When a2 is 2 or more, each of the multiple LA1s is independently a single bond or a divalent linking group, and at least one of the multiple LA1s is a divalent linking group. When a2 is 2, from the viewpoint that the orientation degree of the dichroic material becomes higher, it is preferable that one of the two LA1s is a divalent linking group and the other is a single bond.

[0105] In formula (M1-B), examples of divalent linking groups represented by LA1 include -O- and -(CH2). g -、-(CF2) g -, -Si(CH3)2-, -(Si(CH3)2O) g -、-(OSi(CH3)2) g -(g represents an integer from 1 to 10.), -N(Z)-, -C(Z)=C(Z')-, -C(Z)=N-, -N=C(Z)-, -C(Z)2-C(Z')2-, -C(O)-, -OC(O)-, -C(O)O-, -OC(O)O-, -N(Z)C(O)-, -C (O)N(Z)-, -C(Z)=C(Z')-C(O)O-, -OC(O)-C(Z)=C(Z')-, -C(Z)=N-, -N=C(Z)-, -C(Z)=C(Z')-C(O)N(Z”)-, -N(Z”)-C(O)-C(Z)=C(Z’)-,- C(Z)=C(Z')-C(O)-S-, -SC(O)-C(Z)=C(Z')-, -C(Z)=NN=C(Z')- (Z, Z', Z” independently represent a hydrogen atom, C1-C4 alkyl, cycloalkyl, aryl, cyano, or halogen atom, respectively.), -C≡C-, -N=N-, -S-, -S(O)-, -S(O)(O)-, -(O)S(O)O-, -O(O)S(O)O-, -SC(O)-, and -C(O)S-. Among these, -C(O)O- is preferred from the viewpoint that the orientation degree of dichroic substances becomes higher. LA1 can be a group obtained by combining two or more of these groups.

[0106] In the above formula (1), the terminal group represented by T1 can be, for example, hydrogen atom, halogen atom, cyano, nitro, hydroxyl, alkyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, alkylthio with 1 to 10 carbon atoms, alkoxycarbonyloxy with 1 to 10 carbon atoms, alkoxycarbonyl with 1 to 10 carbon atoms (ROC(O)-: R is alkyl), acyloxy with 1 to 10 carbon atoms, acylamino with 1 to 10 carbon atoms, alkoxycarbonylamino with 1 to 10 carbon atoms, sulfonylamino with 1 to 10 carbon atoms, aminosulfonyl with 1 to 10 carbon atoms, carbamoyl with 1 to 10 carbon atoms, thionyl with 1 to 10 carbon atoms, urea with 1 to 10 carbon atoms, and groups containing (meth)acryloyloxy. Examples of groups containing (meth)acryloyloxy groups include, for instance, the group represented by -LA (L represents a single bond or a linking group. Specific examples of linking groups are the same as those for L1 and SP1 above. A represents (meth)acryloyloxy).

[0107] From the viewpoint that the orientation degree of dichroic substances becomes higher, T1 is preferably an alkoxy group with 1 to 10 carbon atoms, more preferably an alkoxy group with 1 to 5 carbon atoms, and even more preferably a methoxy group.

[0108] These terminal groups can be further substituted with these groups or polymeric groups as described in Japanese Patent Application Publication No. 2010-244038.

[0109] From the viewpoint that the adhesion between the polarizer and the optical anisotropic layer is improved and the cohesion of the film is enhanced, T1 is preferably a polymeric group.

[0110] As a polymerizable group, it is preferably a free radical polymerizable group or a cationic polymerizable group.

[0111] As a free radical polymerizable group, commonly known free radical polymerizable groups can be used, preferably acryloyl or methacryloyl. Regarding polymerization rate, acryloyl is known to be generally faster, and from the viewpoint of improving productivity, acryloyl is preferred; however, methacryloyl can also be used as a polymerizable group in the same way.

[0112] As a cationic polymerizable group, commonly known cationic polymerizable groups can be used, such as alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spiroorthoester groups, and ethyleneoxy groups. Among these, alicyclic ether groups or ethyleneoxy groups are preferred, and epoxy groups, oxetyl groups, or ethyleneoxy groups are more preferred.

[0113] The weight-average molecular weight (Mw) of the polymeric liquid crystal compound containing the repeating unit represented by formula (1) above is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. As long as the Mw of the polymeric liquid crystal compound is within the above range, the processing of the polymeric liquid crystal compound becomes easy.

[0114] In particular, from the viewpoint of suppressing cracks during coating, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably 10,000 or more, and more preferably 10,000 to 300,000.

[0115] Furthermore, from the viewpoint of temperature tolerance of orientation, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably less than 10,000, and more preferably 2,000 or more but less than 10,000.

[0116] In this invention, the weight-average molecular weight and number-average molecular weight are values ​​obtained by gel permeation chromatography (GPC).

[0117] • Solvent (eluent): N-methylpyrrolidone • Device Name: TOSOH HLC-8220GPC • String: Connects 3 TOSOH TSKgel Super AWM-H tubes (6mm x 15cm) for use • Column temperature: 25℃ • Sample concentration: 0.1% by mass • Flow rate: 0.35 mL / min • Calibration curves: Calibration curves were obtained using seven samples based on TOSOH-prepared TSK standard polystyrene with Mw values ​​ranging from 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06). The content of the first liquid crystal compound is preferably 50% by mass or more, more preferably 70% by mass or more, relative to the total solid content of the composition for polarizer formation. There is no particular upper limit, but it is more common to find it to be 95% by mass or less.

[0118] The term "total solids content of the composition for polarizer formation" refers to the components in the composition for polarizer formation other than the solvent. Specific examples of solids content include the first liquid crystal compound mentioned above, the dichroic substance described later, the polymerization initiator, and the surfactant.

[0119] (Dichroic substances) There are no particular limitations on dichroic materials. Examples include visible light absorbing materials (dichroic pigments), luminescent materials (fluorescent materials, phosphorescent materials), ultraviolet light absorbing materials, infrared light absorbing materials, nonlinear optical materials, carbon nanotubes, and inorganic materials (such as quantum rods). Previously known dichroic materials (dichroic pigments) can be used.

[0120] For example, we can cite paragraphs

[0067] to

[0071] of Japanese Patent Application Publication No. 2013-228706, paragraphs

[0008] to

[0026] of Japanese Patent Application Publication No. 2013-227532, paragraphs

[0008] to

[0015] of Japanese Patent Application Publication No. 2013-209367, paragraphs

[0045] to

[0058] of Japanese Patent Application Publication No. 2013-014883, paragraphs

[0012] to

[0029] of Japanese Patent Application Publication No. 2013-109090, and Japanese Patent Application Publication No. 2013-101328. Paragraphs

[0009] to

[0017] , paragraphs

[0051] to

[0065] of Japanese Patent Application Publication No. 2013-037353, paragraphs

[0049] to

[0073] of Japanese Patent Application Publication No. 2012-063387, paragraphs

[0016] to

[0018] of Japanese Patent Application Publication No. Hei 11-305036, paragraphs

[0009] to

[0011] of Japanese Patent Application Publication No. 2001-133630, paragraphs

[0030] to

[0169] of Japanese Patent Application Publication No. 2011-215337, and Japanese Patent Application Publication No. 2010-10624 Paragraphs

[0021] to

[0075] of Japanese Announcement No. 2, paragraphs

[0011] to

[0025] of Japanese Announcement No. 2010-215846, paragraphs

[0017] to

[0069] of Japanese Announcement No. 2011-048311, paragraphs

[0013] to

[0133] of Japanese Announcement No. 2011-213610, paragraphs

[0074] to

[0246] of Japanese Announcement No. 2011-237513, paragraphs

[0005] to

[0051] of Japanese Announcement No. 2016, and WO2016 The substances described in paragraphs

[0005] to

[0041] of Publication No. 060173, paragraphs

[0008] to

[0062] of Publication No. WO2016 / 136561, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154835, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154695, paragraphs

[0013] to

[0037] of International Publication No. 2017 / 195833, and paragraphs

[0014] to

[0034] of International Publication No. 2018 / 164252.

[0121] In this invention, two or more dichroic materials can be used simultaneously. For example, from the viewpoint of making the obtained polarizer close to black, it is preferable to use at least one dichroic material with a maximum absorption wavelength in the range of wavelengths above 370 nm and below 500 nm and at least one dichroic material with a maximum absorption wavelength in the range of wavelengths above 500 nm and below 700 nm.

[0122] The aforementioned dichroic substances may have cross-linking groups.

[0123] Examples of crosslinking groups include (meth)acryloyl, epoxy, oxetyl, and styryl, with (meth)acryloyl being preferred.

[0124] The content of the dichroic substance relative to 100 parts by mass of the above-mentioned liquid crystal compound is preferably 2 to 80 parts by mass, more preferably 5 to 30 parts by mass.

[0125] Furthermore, the content of the dichroic substance is preferably 1 to 40% by mass of the solid component in the polarizer forming composition, more preferably 2 to 30% by mass.

[0126] (Other ingredients) The composition for forming a polarizer may contain other components besides the first liquid crystal compound and the dichroic material described above.

[0127] The composition for polarizer formation preferably contains a polymerization initiator.

[0128] There are no particular restrictions on the type of polymerization initiator, but photosensitive compounds, i.e., photopolymerization initiators, are preferred.

[0129] Various compounds can be used as photopolymerization initiators without particular limitations. Examples of photopolymerization initiators include α-carbonyl compounds (as described in U.S. Patent Nos. 2,367,661 and 2,367,670), azobin ethers (as described in U.S. Patent No. 2,448,828), α-hydrocarbon-substituted aromatic azobin compounds (as described in U.S. Patent No. 2,722,512), polynuclear quinone compounds (as described in U.S. Patent Nos. 3,046,127 and 2,951,758), combinations of triarylimidazolium dimers and p-aminophenyl ketones (as described in U.S. Patent No. 3,549,367), acridine and phenazine compounds (as described in Japanese Patent Application Publication No. 60-105,667 and U.S. Patent No. 4,239,850), oxadiazole compounds (as described in U.S. Patent No. 4,212,970), and o-acyl oximes. oxime) compounds (Japanese Patent Application Publication No. 2016-027384

[0065] ) and acylphosphine oxide compounds (Japanese Patent Publication No. 63-040799, Japanese Patent Publication No. 5-029234, Japanese Patent Application Publication No. 10-095788 and Japanese Patent Application Publication No. 10-029997).

[0130] When the composition for forming the polarizer contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 30 parts by mass relative to the total of 100 parts by mass of the dichroic substance and the liquid crystal compound, more preferably 0.1 to 15 parts by mass.

[0131] The composition for polarizer formation preferably contains a surfactant.

[0132] By including surfactants, the following effects are expected: improving the smoothness of the coated surface and further improving the orientation, or suppressing depressions and unevenness to improve in-plane uniformity.

[0133] As a surfactant, a surfactant that makes the dichroic substance and the liquid crystal compound horizontal on the coating surface side is preferred. For example, the compounds described in paragraphs

[0155] to

[0170] of International Publication No. 2016 / 009648 and the compounds described in paragraphs

[0253] to

[0293] of Japanese Patent Application Publication No. 2011-237513 (horizontal orientation agent) can be cited.

[0134] When the composition for forming the polarizer contains a surfactant, the content of the surfactant is preferably 0.001 to 5 parts by mass relative to the total of 100 parts by mass of the dichroic substance and the liquid crystal compound, more preferably 0.01 to 3 parts by mass.

[0135] From an operational point of view, the composition for polarizer formation preferably contains a solvent.

[0136] Examples of solvents include ketones, ethers, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, carbon halides, esters, alcohols, cellosolvents, cellosolvent acetates, sulfoxides, amides, and heterocyclic compounds, as well as water. One of these solvents may be used alone, or two or more may be used simultaneously.

[0137] When the polarizer forming composition contains a solvent, the solvent content is preferably 80 to 99% by mass, more preferably 83 to 97% by mass, relative to the total mass of the polarizer forming composition.

[0138] (Methods for manufacturing polarizers) Regarding the manufacturing method of the polarizer, there are no particular limitations as long as a polarizer forming composition is used, but it is preferable to form a coating film by coating the polarizer forming composition onto a specified support to orient the liquid crystal components in the coating film.

[0139] Furthermore, the liquid crystal component includes not only the first liquid crystal compound mentioned above, but also, in the case that the dichroic material has liquid crystal properties, a dichroic material having liquid crystal properties.

[0140] There are no particular limitations on the support for the composition used to coat the polarizer. The support will be described in detail later.

[0141] In addition, the support may have an orientation layer on its surface.

[0142] Methods for forming oriented films include, for example, the friction treatment of the film surface with organic compounds (preferably polymers), the tilting evaporation of inorganic compounds, the formation of layers with microgrooves, and the accumulation of organic compounds (e.g., ω-trisanoic acid, dioctadecylmethylammonium chloride, methyl stearate, etc.) based on the Langmuir-Blodgett process (LB film).

[0143] As the alignment layer, an alignment film formed by friction treatment or a photoalignment film formed by light irradiation is preferred.

[0144] Known materials can be cited as photoalignment compounds included in photoalignment films. Preferably, a photosensitive compound having at least one photoreactive group that undergoes dimerization or isomerization upon the action of light is used.

[0145] Furthermore, the polarizer forming composition can also be coated onto the optical anisotropic layer described later, in which case the optical anisotropic layer functions as an alignment film.

[0146] There are no particular limitations on the method of coating the polarizer composition, and examples include curtain coating, dip coating, spin coating, printing coating, spray coating, slot coating, roller coating, sliding coating, doctor blade coating, gravure coating, and wire rod coating.

[0147] There are no particular limitations on the method for orienting the liquid crystal components in the coating film, but heat treatment is preferred.

[0148] From the perspective of manufacturing applicability, the heat treatment is preferably 10 to 250°C, more preferably 25 to 190°C. Furthermore, the heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0149] After heat treatment, cooling treatment can be performed as needed. Cooling treatment involves cooling the heated coating film to room temperature (around 20-25°C). This helps to fix the orientation of the liquid crystal components contained in the coating film. There are no particular limitations on the cooling method, and it can be implemented using known methods.

[0150] Furthermore, after aligning the liquid crystal components, a curing process can be carried out as needed.

[0151] In cases where the polarizer contains cross-linking groups (polymeric groups), the curing process is carried out by heating and / or light irradiation (exposure).

[0152] (Characteristics of polarizers) The content of the dichroic material in the polarizer is 40% by mass or less relative to the total mass of the polarizer. From the viewpoint that even after prolonged exposure of the display device including the polarizer of the present invention to a high-temperature environment, the black density in the front direction is superior (hereinafter also referred to as "the viewpoint of superior effect of the present invention"), the content of the dichroic material relative to the total mass of the polarizer is preferably 30% by mass or less. There is no particular limitation on the lower limit of the content of the dichroic material, but it is preferably 3% by mass or more, and more preferably 5% by mass or more, relative to the total mass of the polarizer.

[0153] When analyzing the composition of the polarizer in the depth direction using time-of-flight secondary ion mass spectrometry, the relationship between the maximum intensity Imax of the secondary ion intensity originating from the dichroic material and the intensity Isur1 of the secondary ion intensity originating from the dichroic material on the surface of the polarizer opposite to the optical anisotropy layer side preferably satisfies equation (3), more preferably equation (3-1), and even more preferably equation (3-2). By satisfying the relationship in equation (3) above, even without setting a refractive index adjustment layer or a barrier layer (oxygen barrier layer), the display performance and durability become good, thus enabling the thinning of organic EL display devices.

[0154] Equation (3) 2.0≤Imax / Isur1 Equation (3-1) 5.0≤Imax / Isur1 Equation (3-2) 10.0<Imax / Isur1≤100 Additionally, the average value of the secondary ion intensity of fragments originating from dichroic material in a region of 1% from the surface of the polarizer opposite to the optical anisotropic layer side (the average value of the intensity from the baseline) is set as the intensity Isur1 on the visible side surface.

[0155] Furthermore, the maximum value of the secondary ion intensity (intensity from the baseline) of fragments originating from dichroic materials in the region of 98% of the total thickness, excluding the portion of 1% of the total thickness from each surface, is set as the maximum intensity Imax in the thickness direction.

[0156] The methods described above can be cited as measurement methods for time-of-flight secondary ion mass spectrometry.

[0157] Furthermore, when the polarizer contains two or more dichroic substances, the secondary ion intensity of fragments originating from dichroic substances (hereinafter also referred to as "the dichroic substance to be measured") that have a maximum absorption wavelength in the wavelength range of 500 to 650 nm is measured. When the polarizer contains two or more dichroic substances to be measured, the secondary ion intensity of fragments originating from the dichroic substance with the highest absorbance among the dichroic substances to be measured is measured.

[0158] There is no particular limitation on the thickness of the polarizer, but it is preferably 100 to 8000 nm, more preferably 300 to 5000 nm.

[0159] In addition, the thickness of the polarizer refers to the average thickness of the polarizer. This average thickness is calculated by measuring the thickness of any five or more parts of the polarizer and then averaging them.

[0160] <Optical Anisotropic Layer> The optical anisotropic layer is formed using a composition containing a second liquid crystal compound (hereinafter also referred to as a composition for forming an optical anisotropic layer).

[0161] The materials contained in the composition for forming an optical anisotropic layer will be described in detail below.

[0162] (Second liquid crystal compound) As a second liquid crystal compound, well-known liquid crystal compounds can be cited.

[0163] Liquid crystal compounds are typically classified into rod-shaped and disc-shaped types based on their shape. Furthermore, they are categorized into low-molecular-weight and high-molecular-weight types. High-molecular-weight compounds generally refer to compounds with a degree of polymerization of 100 or higher (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992).

[0164] The second liquid crystal compound is preferably a rod-shaped liquid crystal compound or a disc-shaped liquid crystal compound, and more preferably a rod-shaped liquid crystal compound.

[0165] As a rod-shaped liquid crystal compound, the compound described in claim 1 of Japanese Patent Application Publication No. 11-513019 or in paragraphs

[0026] to

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

[0020] to

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

[0013] to

[0108] of Japanese Patent Application Publication No. 2010-244038 is preferred, but it is not limited to these.

[0166] The second liquid crystal compound preferably has polymerizable groups.

[0167] Furthermore, there are no particular limitations on the type of polymerizable group, but functional groups capable of undergoing addition polymerization are preferred, and polymerizable olefinic unsaturated groups or cyclic polymerizable groups are preferred. More specifically, (meth)acryloyl, vinyl, styrene, or allyl are preferred, and (meth)acryloyl is more preferred. Additionally, (meth)acryloyl is a designation representing methacryloyl or acryloyl.

[0168] Furthermore, as the second liquid crystal compound, a liquid crystal compound with reverse wavelength dispersion can be used.

[0169] In this specification, a liquid crystal compound with "reverse wavelength dispersion" refers to a liquid crystal compound in which the in-plane retardation (Re) value becomes equal or higher as the measurement wavelength increases when the in-plane retardation (Re) value of a phase retardation film made using this compound is measured at a specific wavelength (visible light range).

[0170] Furthermore, there are no particular limitations as long as the liquid crystal compound with reverse wavelength dispersion is a compound that can form a film with reverse wavelength dispersion as described above. For example, compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2010-084032 (especially the compounds described in paragraphs

[0067] to

[0073] ), compounds represented by general formula (II) as described in Japanese Patent Application Publication No. 2016-053709 (especially the compounds described in paragraphs

[0036] to

[0043] ), and compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2016-081035 (especially the compounds described in paragraphs

[0043] to

[0055] ).

[0171] There is no particular limitation on the absolute value of the difference between logP of the second liquid crystal compound and logP of the dichroic material, but from the viewpoint of better performance of the present invention, it is preferable to be 3.0 or more, and more preferably 4.0 to 6.0. When the absolute value of the difference is 3.0 or more, it is difficult for the dichroic material in the polarizer to transfer to the optical anisotropy layer side.

[0172] Furthermore, when using multiple dichroic materials, it is preferable that the absolute value of the difference between the logP of the second liquid crystal compound and the logP of each dichroic material is within the aforementioned range.

[0173] Furthermore, when using multiple second liquid crystal compounds, it is preferable that the absolute value of the difference between the logP of each second liquid crystal compound and the logP of the dichroic substance is within the aforementioned range.

[0174] Furthermore, when multiple second liquid crystal compounds and dichroic substances are used respectively, it is preferable that the absolute value of the difference between the logP of the second liquid crystal compound and the logP of the dichroic substance in each of the multiple combinations of the second liquid crystal compound and the dichroic substance is within the above-mentioned range.

[0175] The logP value is an indicator of the hydrophilicity and hydrophobicity of a chemical structure, sometimes referred to as the hydrophilic-hydrophobic parameter. The logP value for each compound can be calculated using software such as ChemBioDraw Ultra or HSPiP (Version 4.1.07). It can also be experimentally determined using methods outlined in the OECD Guidelines for the Testing of Chemicals, Section 1, Test No. 117. In this invention, unless otherwise specified, the logP value is calculated by inputting the compound's structural formula into HSPiP (Version 4.1.07).

[0176] The content of the second liquid crystal compound is preferably 50% by mass or more, more preferably 70% by mass or more, relative to the total solid content of the composition for forming the optical anisotropic layer. There is no particular upper limit, but it is more common to find it to be 95% by mass or less.

[0177] Here, "solid components of the composition for forming an optical anisotropic layer" refers to the components in the composition for forming an optical anisotropic layer other than the solvent. Specific examples of solid components include the second liquid crystal compound mentioned above, the polymerization initiator described later, and the surfactant.

[0178] (Other ingredients) The composition for forming an optical anisotropic layer may contain other components besides the second liquid crystal compound.

[0179] Regarding compositions for forming optical anisotropic layers, examples include polymerization initiators, surfactants, and solvents that can be included in compositions for forming polarizers.

[0180] The content of polymerization initiator in the composition for forming optical anisotropic layers is preferably 0.01 to 20% by mass relative to the total solid content of the composition for forming optical anisotropic layers, more preferably 0.3 to 10% by mass.

[0181] Furthermore, the composition for forming an optical anisotropic layer may contain polymerizable monomers.

[0182] Examples of polymerizable monomers include free radical polymerizable compounds and cationic polymerizable compounds. Among these, multifunctional free radical polymerizable monomers are preferred. Furthermore, liquid crystal compounds and comonomers having polymerizable groups as described above are preferred. For example, the polymerizable monomers described in paragraphs

[0018] to

[0020] of Japanese Patent Application Publication No. 2002-296423 can be cited.

[0183] The content of polymerizable monomers in the composition for forming optical anisotropic layers is preferably 1 to 50% by mass relative to the total mass of the liquid crystal compound, more preferably 2 to 30% by mass.

[0184] The composition for forming an optical anisotropic layer can include various orientation control agents such as vertical alignment agents and horizontal alignment agents. These orientation control agents are compounds capable of controlling the horizontal or vertical orientation of liquid crystal compounds at the interface side.

[0185] (Method for manufacturing optical anisotropic layers) There are no particular limitations on the manufacturing method of the optical anisotropic layer, but the preferred method is as follows: coating an optical anisotropic layer forming composition onto a polarizer to form a coating film, performing an orientation treatment on the coating film to orient the second liquid crystal compound, and performing a curing treatment (ultraviolet irradiation (light irradiation treatment) or heat treatment) on the obtained coating film to form an optical anisotropic layer.

[0186] As described above, a polarizer with the optical anisotropic layer arranged adjacent to it is manufactured by coating the polarizer with a composition for forming an optical anisotropic layer.

[0187] There are no particular limitations on the method for coating the composition for forming an optical anisotropic layer, and the method described above as an example of coating the composition for forming a polarizer can be given.

[0188] Examples of processes for orienting the second liquid crystal compound include drying the coating at room temperature and heating the coating. In the case of thermotropic liquid crystal compounds, the liquid crystal phase formed by the orientation process can usually be transformed by changes in temperature or pressure. In the case of lyotropic liquid crystal compounds, the transformation can also be achieved by changes in the composition ratio of solvents, etc.

[0189] In addition, there are no particular restrictions on the conditions for heating the coating, but the heating temperature is preferably 40 to 250°C, more preferably 50 to 150°C, and the heating time is preferably 10 seconds to 10 minutes.

[0190] Furthermore, after heating the coating and before the curing process (light irradiation treatment) described later, the coating can be cooled as needed. The preferred cooling temperature is 20–200°C, more preferably 30–150°C.

[0191] Next, the coating with the second liquid crystal compound orientation is cured.

[0192] There are no particular limitations on the method for curing the coating film oriented with the second liquid crystal compound; for example, light irradiation and heat treatment can be used. However, from the viewpoint of manufacturing applicability, light irradiation is preferred, and ultraviolet irradiation is more preferred.

[0193] There are no particular restrictions on the irradiation conditions for light treatment, but 50–1000 mJ / cm² is preferred. 2 The amount of radiation.

[0194] (Characteristics of optical anisotropic layers) There is no particular limitation on the thickness of the optical anisotropic layer. From the viewpoint of thinning, it is preferably 10 μm or less, more preferably 0.5 to 8.0 μm, and even more preferably 0.5 to 6.0 μm.

[0195] Furthermore, in this specification, the thickness of the optical anisotropic layer refers to the average thickness of the optical anisotropic layer. This average thickness is calculated by measuring the thickness of any five or more locations within the optical anisotropic layer and then arithmetically averaging them.

[0196] Optical anisotropic layers can also be tuned for in-plane retardation to function as so-called λ / 4 or λ / 2 plates.

[0197] Additionally, a λ / 4 plate is a plate that has the function of converting linearly polarized light of a specific wavelength into circularly polarized light (or, converting circularly polarized light into linearly polarized light). More specifically, a λ / 4 plate is a plate whose in-plane delay Re at a specified wavelength λnm is represented by λ / 4 (or, an odd multiple thereof).

[0198] The in-plane delay (Re(550)) of the λ / 4 plate at a wavelength of 550nm can have an error of about 25nm centered on the ideal value (137.5nm), for example, preferably 110-160nm, more preferably 120-150nm.

[0199] Furthermore, the λ / 2 plate refers to an optically anisotropic film whose in-plane retardation Re(λ) at a specific wavelength λnm satisfies Re(λ) ≈ λ / 2. This formula can be realized at any wavelength in the visible light region (e.g., 550nm). Preferably, the in-plane retardation Re(550) at a wavelength of 550nm satisfies the following relationship.

[0200] 210nm≤Re(550)≤300nm The angle formed by the absorption axis of the aforementioned polarizer and the in-plane slow axis on the polarizer side surface of the optical anisotropy layer is not particularly limited, but is preferably within 1°, more preferably within 0.5°. The lower limit is not particularly limited, but 0° is an example.

[0201] As will be described later, when the optical anisotropic layer includes a first optical anisotropic layer and a second optical anisotropic layer, from the viewpoint of better performance of the present invention, it is preferable that the angle formed by the absorption axis of the polarizer and the in-plane slow axis on the polarizer-side surface of the first optical anisotropic layer is within the range described above.

[0202] The direction of the absorption axis of the polarizer and the direction of the in-plane slow axis of the optical anisotropy layer were measured using an Axometrics Axoscan polarimeter and analysis software from Axometrics.

[0203] The optical anisotropic layer can be a layer formed by fixing a second liquid crystal compound with a twisted orientation along the thickness direction as the helical axis, or it can be a layer formed by fixing a second liquid crystal compound with a horizontal orientation.

[0204] From the viewpoint of achieving better results with respect to the present invention, a layer formed by fixing a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis is preferred. The twist angle of the second liquid crystal compound is not particularly limited, but is preferably greater than 0° and less than 360°.

[0205] Furthermore, the "fixed" state refers to the state in which the orientation of the liquid crystal compound is maintained. Specifically, it is preferable to maintain a fixed orientation state within a temperature range of -30 to 70°C, typically 0 to 50°C, or more severely, -50 to 50°C, where there is no fluidity in the layer and the orientation morphology is not changed by external fields or forces.

[0206] The optical anisotropic layer can be a single layer or have multiple layers. That is, the optical anisotropic layer can be formed by fixing multiple layers of a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis.

[0207] The optical anisotropic layer is preferably composed of multiple layers with different twist angles of the second liquid crystal compound.

[0208] The twist angles of the preferred second liquid crystal compound in the above-mentioned multiple layers are different.

[0209] Furthermore, the ratio of the twist angle of the second liquid crystal compound to the thickness of the layer (twist angle of the second liquid crystal compound (°) / thickness of the layer (μm)) of the aforementioned multiple layers is different.

[0210] <Preferred method for polarizing filter> As one of the preferred methods for polarizers, one example is a method in which the optical anisotropy layer has a first optical anisotropy layer and a second optical anisotropy layer, which will be described later.

[0211] More specifically, such as Figure 3 As shown, polarizer 10B has a polarizer 12 and an optical anisotropy layer 140, the optical anisotropy layer 140 having a first optical anisotropy layer 16 and a second optical anisotropy layer 18. In the optical anisotropy layer 140, the first optical anisotropy layer 16 is disposed closer to the polarizer 12 than the second optical anisotropy layer 18.

[0212] Polarizer 12 and the above Figure 1 The polarizer 12 shown is the same, and its description is omitted.

[0213] The following is a detailed description of the first optical anisotropic layer 16 and the second optical anisotropic layer 18.

[0214] (First optical anisotropy layer) The first optical anisotropic layer is to be in the thickness direction ( Figure 3The first optical anisotropy layer is formed by fixing a second liquid crystal compound with a twisted orientation (z-axis direction) as the helical axis. The first optical anisotropy layer is preferably formed by fixing a chiral filamentary phase having a so-called helical structure. Furthermore, when forming the above phase, it is preferable to use a mixture of the second liquid crystal compound that displays a nematic liquid crystal phase and the chiral reagent described later.

[0215] In addition, the meaning of the "fixed" state is as described above.

[0216] The twist angle of the second liquid crystal compound in the first optical anisotropic layer is 26.5 ± 10.0°, more preferably 26.5 ± 8.0°, and even more preferably 26.5 ± 6.0°, from the viewpoint of better performance of the present invention.

[0217] In addition, the measurement method for the torsion angle in this specification uses the Axoscan (polarimeter) device from Axometrics Corporation and the analysis software from Axometrics Corporation.

[0218] Furthermore, the twisted orientation of the second liquid crystal compound refers to the twisting of the second liquid crystal compound from one main surface of the first optical anisotropic layer to another, with the thickness direction of the first optical anisotropic layer as the axis. At the same time, the orientation direction (in-plane slow axis direction) of the second liquid crystal compound varies depending on its position in the thickness direction of the first optical anisotropic layer.

[0219] Furthermore, the twisting direction of the second liquid crystal compound in the first optical anisotropic layer can be either right-hand twisted or left-hand twisted. Figure 3 In this context, right-hand distortion refers to the right-hand distortion (clockwise distortion) when viewed from the direction of the second optical anisotropy layer toward the first optical anisotropy layer.

[0220] The product of the refractive index anisotropy Δn1 of the first optical anisotropy layer and the thickness d1 of the first optical anisotropy layer, measured at a wavelength of 550 nm, Δn1·d1, satisfies the following equation (1).

[0221] Equation (1) 252nm≤Δn1·d1≤312nm From the viewpoint of achieving better results from the present invention, it is preferable to satisfy formula (1A), and even more preferably to satisfy formula (1B).

[0222] Equation (1A) 262nm≤Δn1·d1≤302nm Equation (1B) 272nm≤Δn1·d1≤292nm The measurement method for Δn1·d1 is the same as that for the torsion angle, using an Axometrics Axoscan (polarimeter) device and Axometrics analysis software.

[0223] (Second optical anisotropy layer) Similar to the first optical anisotropic layer, the second optical anisotropic layer is formed by extending the thickness direction ( Figure 3 A layer formed by fixing a second rod-shaped liquid crystal compound with a twisted orientation (in the z-axis direction) as the helical axis.

[0224] The twist angle of the second liquid crystal compound is 78.6±10.0°, which is more preferably 78.6±8.0° from the viewpoint of better performance of the present invention, and even more preferably 78.6±6.0°.

[0225] Furthermore, the twisting direction of the second liquid crystal compound in the second optical anisotropy layer is the same as the twisting direction of the second liquid crystal compound in the first optical anisotropy layer. For example, if the twisting direction of the second liquid crystal compound in the first optical anisotropy layer is right-hand twist, then the twisting direction of the second liquid crystal compound in the second optical anisotropy layer is also right-hand twist.

[0226] The product of the refractive index anisotropy Δn2 of the second optical anisotropy layer and the thickness d2 of the second optical anisotropy layer, measured at a wavelength of 550 nm, Δn2·d2, satisfies the following equation (2).

[0227] Equation (2) 110nm≤Δn2·d2≤170nm From the viewpoint of achieving better results from the present invention, it is preferable to satisfy formula (2A), and even more preferably to satisfy formula (2B).

[0228] Equation (2A) 120nm≤Δn2·d2≤160nm Equation (2B) 130nm≤Δn2·d2≤150nm The measurement method for Δn2·d2 is the same as that for the measurement of the torsion angle, using an Axometrics Axoscan (polarimeter) device and Axometrics analysis software.

[0229] The in-plane slow axis on the surface of the first optical anisotropy layer on the second optical anisotropy layer side is arranged parallel to the in-plane slow axis on the surface of the second optical anisotropy layer on the first optical anisotropy layer side. The definition of parallel is as described above.

[0230] (Angle relationship) The absorption axis of the polarizer is parallel to the in-plane slow axis on the surface of the polarizing film side of the first optical anisotropy layer.

[0231] Regarding the relationship between the absorption axis of the polarizer, the in-plane slow axis of the first optical anisotropy layer, and the in-plane slow axis of the second optical anisotropy layer, the following is used: Figure 4 To provide a more detailed explanation.

[0232] Figure 4 The arrows in polarizer 12 indicate the absorption axis, and the arrows in the first optical anisotropic layer 16 and the second optical anisotropic layer 18 indicate the in-plane slow axes of their respective layers. Furthermore, in Figure 5 The text appears to be a mix of Chinese characters and symbols, possibly from different sources. A direct translation wouldn't be meaningful. Figure 4 The relationship between the angles of the absorption axis of polarizer 12, the in-plane slow axis of the first optical anisotropic layer 16, and the in-plane slow axis of the second optical anisotropic layer 18 when observed with a hollow arrow.

[0233] In addition, Figure 5 In the middle, from Figure 4 When observing the hollow arrow, the rotation angle of the slow axis in the plane is set with the absorption axis of polarizer 12 as the reference, with a positive value for counterclockwise and a negative value for clockwise.

[0234] exist Figure 4 In this configuration, the absorption axis of polarizer 12 is parallel to the in-plane slow axis on the surface 16a of the first optical anisotropy layer 16 on the polarizer 12 side. Parallelism is defined as described above.

[0235] As described above, the first optical anisotropy layer 16 is a layer formed by fixing a second liquid crystal compound with a twisted orientation about its thickness direction as the helical axis. Therefore, as Figure 4 As shown, the in-plane slow axis on the surface 16a of the polarizer 12 side of the first optical anisotropy layer 16 and the in-plane slow axis on the surface 16b of the second optical anisotropy layer 18 side of the first optical anisotropy layer 16 form the aforementioned twist angle (in addition, in Figure 4 The angle φ2 formed by the absorption axis of the polarizer 12 and the in-plane slow axis on the surface 16b of the first optical anisotropy layer 16 is 26.5°. That is, the in-plane slow axis of the first optical anisotropy layer 16 is rotated by -26.5° (clockwise rotation of 26.5°). Therefore, the angle φ2 formed by the absorption axis of the polarizer 12 and the in-plane slow axis on the surface 16b of the first optical anisotropy layer 16 is 26.5°.

[0236] In addition, Figure 5 The diagram shows the in-plane slow axis on surface 16b of the first optical anisotropy layer 16 rotating 26.5° clockwise relative to the in-plane slow axis on surface 16a of the first optical anisotropy layer 16, but it is not limited to this method, and the rotation angle is only required to be within the range of 26.5 ± 10° clockwise.

[0237] exist Figure 4In this configuration, the in-plane slow axis on the surface 16b of the first optical anisotropy layer 16 on the side of the second optical anisotropy layer 18 is parallel to the in-plane slow axis on the surface 18a of the second optical anisotropy layer 18 on the side of the first optical anisotropy layer 16. That is, the angle φ3 formed by the absorption axis of the polarizer 12 and the in-plane slow axis on the surface 18a of the second optical anisotropy layer 18 on the side of the first optical anisotropy layer 16 is approximately the same as the aforementioned angle φ2b.

[0238] As described above, the second optical anisotropy layer 18 is a layer formed by fixing a liquid crystal compound with a twisted orientation about its thickness direction as the helical axis. Therefore, as Figure 4 As shown, the in-plane slow axis on the surface 18a of the second optical anisotropy layer 18 on the side of the first optical anisotropy layer 16 forms the aforementioned twist angle with the in-plane slow axis on the surface 18b of the second optical anisotropy layer 18 on the side opposite to the first optical anisotropy layer 16 (in addition, in Figure 4 The angle φ4 formed by the absorption axis of the polarizer 12 and the in-plane slow axis on the surface 18b of the second optical anisotropy layer 18 is 105.1°. That is, the in-plane slow axis of the second optical anisotropy layer 18 rotates by -78.6° (78.6° clockwise). Therefore, the angle φ4 formed by the absorption axis of the polarizer 12 and the in-plane slow axis on the surface 18b of the second optical anisotropy layer 18 is 105.1°.

[0239] In addition, Figure 4 The diagram shows the in-plane slow axis on surface 18b of the second optical anisotropy layer 18 rotating 78.6° clockwise relative to the in-plane slow axis on surface 18a of the second optical anisotropy layer 18. However, it is not limited to this method, and the rotation angle is only required to be within the range of clockwise -78.6 ± 10°.

[0240] As mentioned above, in Figure 4 In this method, with the absorption axis of polarizer 12 as a reference, the twisting direction of the second liquid crystal compound in the first optical anisotropy layer 16 and the second optical anisotropy layer 18 is clockwise (right twist).

[0241] exist Figure 4 The text describes in detail the clockwise (right-hand twist) twisting direction, but it can also be described that the twisting direction of the second liquid crystal compound in the first optical anisotropy layer 16 and the second optical anisotropy layer 18 is counterclockwise.

[0242] (Preferred manufacturing method) There are no particular limitations on the preferred method for manufacturing the optical anisotropic layer, which includes the first optical anisotropic layer and the second optical anisotropic layer, but the following steps 1 to 5 can be performed. By performing the following steps 1 to 5, the optical anisotropic layer, which includes the first optical anisotropic layer and the second optical anisotropic layer, can be manufactured in one coating step.

[0243] Step 1: A step of coating a polymeric liquid crystal composition onto a polarizer to form a composition layer, wherein the polymeric liquid crystal composition comprises at least a chiral reagent containing a photosensitive chiral reagent whose helical torsional force changes upon light irradiation and a liquid crystal compound having polymeric groups (hereinafter, in the description of steps 1 to 5, it is also simply referred to as "liquid crystal compound"). Step 2: A process of heat-treating the composition layer to cause the liquid crystal compound in the composition layer to be twisted and oriented along a spiral axis extending in the thickness direction. Step 3: Following Step 2, the composite layer is irradiated with light under conditions where the oxygen concentration is 1% by volume or higher. Step 4: A step after step 3, in which the composite layer is subjected to heat treatment. Step 5: Following step 4, a curing process is performed on the composite layer to fix the orientation state of the liquid crystal compound, thereby forming the first optical anisotropic layer and the second optical anisotropic layer. The steps of each of the above processes are described in detail below.

[0244] [Process 1] Step 1 is a step of coating a polymeric liquid crystal composition onto a polarizer to form a composition layer. The polymeric liquid crystal composition comprises at least a chiral reagent containing a photosensitive chiral reagent whose helical torsional force changes upon light irradiation, and a liquid crystal compound having polymeric groups. By performing this step, a composition layer subjected to the light irradiation treatment described later can be formed.

[0245] As various components included in the polymeric liquid crystal composition, examples that can be included in the above-mentioned optical anisotropic layer forming composition are listed below. Photosensitive chiral reagents not described above will be described in detail below.

[0246] In addition, the helical torsional force (HTP) of the chiral reagent is a factor representing the helical orientation capability expressed by the following formula (X).

[0247] Formula (X) HTP = 1 / (length of helical pitch (unit: μm) × concentration of chiral reagent relative to liquid crystal compound (mass%)) [μm -1 ] The length of the helical pitch refers to the length of the pitch P (=the period of the helix) of the helical structure of the cholesterol-type liquid crystal phase, which can be measured using the method described on page 196 of the Liquid Crystal Handbook (published by MARUZEN GROUP).

[0248] A photosensitive chiral reagent (hereinafter, also referred to as "chiral reagent A") whose helical torsional force changes upon light irradiation can be either liquid crystal or non-liquid crystal. Chiral reagent A typically contains asymmetric carbon atoms. Alternatively, chiral reagent A can be an axially asymmetric compound or a surface asymmetric compound that does not contain asymmetric carbon atoms.

[0249] Chiral reagent A can have polymerizable groups.

[0250] Chiral reagent A can be either a chiral reagent whose helical torsional force increases upon light irradiation or a chiral reagent whose helical torsional force decreases. Preferably, it is a chiral reagent whose helical torsional force decreases upon light irradiation.

[0251] Furthermore, in this specification, "increase and decrease of helical torsional force" refers to the increase or decrease when the initial (before light irradiation) helical direction of chiral reagent A is set to "positive". Therefore, when the helical torsional force continuously decreases and exceeds 0 due to light irradiation and the helical direction becomes "negative" (i.e., when the helical direction is reversed from the initial (before light irradiation) helical direction), it also corresponds to "chiral reagent with decreased helical torsional force".

[0252] As a chiral reagent A, a so-called photoreactive chiral reagent can be cited. A photoreactive chiral reagent is a compound that has a chiral site and a photoreactive site whose structure changes upon light irradiation, for example, causing a significant change in the torsional force of a liquid crystal compound depending on the amount of irradiation.

[0253] As the chiral reagent A, it is preferably a compound having at least a photoisomerization site, and the photoisomerization site is more preferably having a double bond capable of photoisomerization. As the aforementioned photoisomerization site having a double bond capable of photoisomerization, from the viewpoint of easy photoisomerization and a large difference in helical torsional force before and after light irradiation, a cinnamoyl site, a chalcone site, an azobenzene site, or a stilbene site is preferred; further from the viewpoint of low absorption of visible light, a cinnamoyl site, a chalcone site, or a stilbene site is more preferred. Furthermore, the photoisomerization site corresponds to the aforementioned photoreaction site whose structure changes upon light irradiation.

[0254] As the chiral reagent A, the compound represented by formula (C) is preferred.

[0255] Formula (C) RLR R independently represents a group having at least one part selected from the group consisting of cinnamyl, chalcone, azobenzene and stilbene.

[0256] L represents a divalent linker formed by removing two hydrogen atoms from the structure represented by formula (D) (a divalent linker formed by removing two hydrogen atoms from the above-mentioned naphthalene moiety), a divalent linker represented by formula (E) (a divalent linker composed of the above-mentioned isosorbide moiety), or a divalent linker represented by formula (F) (a divalent linker composed of the above-mentioned isomannitol moiety).

[0257] [Chemical Formula 4] In step 1, at least the chiral reagent A described above can be used. Step 1 can be performed by using two or more chiral reagents A, or by using at least one chiral reagent A and at least one chiral reagent whose helical torsional force does not change upon light irradiation (hereinafter also referred to as "chiral reagent B").

[0258] Chiral reagent B can be either liquid crystal or non-liquid crystal. Chiral reagent B typically contains asymmetric carbon atoms. Alternatively, chiral reagent B can be an axially asymmetric compound or a surface-asymmetric compound that does not contain asymmetric carbon atoms.

[0259] Chiral reagent B can have polymerizable groups.

[0260] As chiral reagent B, known chiral reagents can be used.

[0261] Chiral reagent B is preferably a chiral reagent whose helix twists in the opposite direction to that of chiral reagent A. That is, for example, if the helix twisted by chiral reagent A is to the right, the helix twisted by chiral reagent B is to the left.

[0262] The content of the chiral reagent A in the composition layer is not particularly limited, but from the viewpoint that the liquid crystal compound can be easily and uniformly oriented, it is preferably 5.0% by mass or less relative to the total mass of the liquid crystal compound, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, particularly preferably less than 1.0% by mass, even more preferably 0.8% by mass or less, and most preferably 0.5% by mass or less. The lower limit is not particularly limited, but it is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.05% by mass or more.

[0263] Furthermore, the chiral reagent A described above can be used alone or in combination with two or more other chiral reagents. When two or more chiral reagents A are used simultaneously, the total content is preferably within the range described above.

[0264] The content of the chiral reagent B in the composition layer is not particularly limited, but from the viewpoint that the liquid crystal compound can be easily and uniformly oriented, it is preferably 5.0% by mass or less relative to the total mass of the liquid crystal compound, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, particularly preferably less than 1.0% by mass, even more preferably 0.8% by mass or less, and most preferably 0.5% by mass or less. The lower limit is not particularly limited, but it is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.05% by mass or more.

[0265] Furthermore, the chiral reagent B described above can be used alone or in combination with two or more. When two or more chiral reagents B are used simultaneously, the total content is preferably within the range described above.

[0266] The total content of chiral reagents in the composition layer (the total content of all chiral reagents) is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less, relative to the total mass of the liquid crystal compound. There is no particular limitation on the lower limit, but it is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.05% by mass or more.

[0267] There are no particular limitations on the method of forming a composition layer by coating a polymerizable liquid crystal composition, and the above-described method of coating a composition for forming a polarizer can be cited as an example.

[0268] There is no particular limitation on the film thickness of the composition layer, but it is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm, and even more preferably 0.5 to 10 μm.

[0269] (Process 2) Step 2 involves heat treatment of the composition layer to cause the polymeric liquid crystal compound in the composition layer to be twisted and oriented along a spiral axis extending in the thickness direction.

[0270] The optimal conditions for heat treatment are selected based on the liquid crystal compound used.

[0271] Among these, the heating temperatures are mostly between 10 and 250°C, even more so between 40 and 150°C, and even more so between 50 and 130°C.

[0272] The heating time is typically 0.1 to 60 minutes, with 0.2 to 5 minutes being more common.

[0273] The absolute value of the weighted average helical torsional force of the chiral reagent in the composition layer formed by step 1 is preferably greater than 0 μm. -1 More preferably, greater than 0 μm-1 And 1.9μm -1 Below, we further prefer sizes exceeding 0 μm. -1 And 1.5μm -1 The following, especially those exceeding 0.00 μm, are preferred. -1 And 1.0μm -1 the following.

[0274] Furthermore, the weighted average helical torsional force of the chiral reagent represents the sum of the values ​​obtained by dividing the product of the helical torsional force of each chiral reagent in the composition layer and the concentration (mass%) of each chiral reagent in the composition layer by the total concentration (mass%) of the chiral reagents in the composition layer when two or more chiral reagents are included in the composition layer. For example, when two types of chiral reagents (chiral reagent X and chiral reagent Y) are used simultaneously, it is represented by the following formula (Y).

[0275] Equation (Y) Weighted average helical torsional force (μm) -1 = (helical torsional force of chiral reagent X (μm)) -1 × Concentration (mass%) of chiral reagent X in the composition layer + Helical torsion force (μm) of chiral reagent Y -1 () × Concentration (mass%) of chiral reagent Y in the composition layer / (Concentration (mass%) of chiral reagent X in the composition layer + Concentration (mass%) of chiral reagent Y in the composition layer) In the above formula (Y), when the chiral reagent has a right-handed helix, its torsional force is set to a positive value. Furthermore, when the chiral reagent has a left-handed helix, its torsional force is set to a negative value. That is, for example, when the torsional force is 10 μm... -1 In the case of chiral reagents, when the helical direction of the helix twisted by the aforementioned chiral reagent is right-handed, the helical torsional force is expressed as 10 μm. -1 On the other hand, when the helix twisted by the aforementioned chiral reagent is left-handed, the torsional force is expressed as -10 μm. -1 .

[0276] The absolute value of the weighted average helical torsional force of the chiral reagent in the composition layer formed by step 1 exceeds 0 μm. -1 In such cases, Figure 6 As shown, a composition layer 20 of liquid crystal compound LC is formed on polarizer 12, which is twisted and oriented along a helical axis extending in the thickness direction.

[0277] in addition, Figure 6 This is a schematic cross-sectional view of the polarizer 12 and the composite layer 20. Figure 6The composition layer 20 shown contains chiral reagent A and chiral reagent B, with a higher concentration of chiral reagent B than chiral reagent A. The helical direction of the chiral reagent A is left-handed, while the helical direction of the chiral reagent B is right-handed. Furthermore, the absolute value of the helical torsional force of chiral reagent A is the same as the absolute value of the helical torsional force of chiral reagent B.

[0278] (Process 3) Step 3 is a step following step 2, in which the composition layer is irradiated with light in the presence of oxygen. The mechanism of this step will be described below using the accompanying drawings.

[0279] like Figure 7 As shown, in the above-mentioned step 2, under the condition that the oxygen concentration is 1% by volume or more, the direction from the side of the polarizer 12 opposite to the side of the composition layer 20 ( Figure 7 The direction of the hollow arrow in the image is used for illumination. Additionally, in... Figure 7 In this process, light irradiation is performed from the polarizer 12 side, but it can also be performed from the composition layer 20 side.

[0280] At this point, if we compare the first region 20A on the polarizer 12 side of the composition layer 20 with the second region 20B on the opposite side of the polarizer 12 side, the surface of the second region 20B is on the air side, therefore the oxygen concentration in the second region 20B is high, and the oxygen concentration in the first region 20A is low. Therefore, if the composition layer 20 is irradiated with light, the liquid crystal compound readily polymerizes in the first region 20A, and the orientation state of the liquid crystal compound is fixed. Furthermore, chiral reagent A is also present in the first region 20A, and the chiral reagent A is also photosensitive, causing a change in the helical torsion force. However, since the orientation state of the liquid crystal compound is fixed in the first region 20A, even if step 4, which describes the heat treatment of the light-irradiated composition layer, is performed later, no change in the orientation state of the liquid crystal compound will occur.

[0281] Furthermore, due to the high oxygen concentration in region 20B, the polymerization of the liquid crystal compound is hindered by oxygen even under light irradiation, making polymerization difficult. Moreover, chiral reagent A is also present in region 20B, and therefore, the helical torsion force changes upon photosensitive reaction. Thus, if step 4 (heat treatment) is performed later, the orientation state of the liquid crystal compound changes along with the altered helical torsion force.

[0282] That is, by implementing step 3, the orientation state of the liquid crystal compound can be easily fixed in the region on the polarizer side of the composition layer. However, it is difficult to fix the orientation state of the liquid crystal compound in the region on the side of the composition layer opposite to the polarizer side, resulting in a state where the helical torsional force varies according to the photosensitive chiral reagent A.

[0283] Step 3 is performed under conditions where the oxygen concentration is 1% by volume or more. From the viewpoint that regions with different orientation states are more likely to form liquid crystal compounds in the optical anisotropy layer, the oxygen concentration is preferably 2% by volume or more, and more preferably 5% by volume or more. There is no particular upper limit, but 100% by volume can be cited as an example.

[0284] The intensity of light irradiation in step 3 is not particularly limited and can be appropriately determined based on the helical torsional force of chiral reagent A. The amount of light irradiation in step 3 is not particularly limited, but from the viewpoint of easily forming a specified optical anisotropy layer, 300 mJ / cm² is preferred. 2 Below, 200 mJ / cm is more preferred. 2 Below. As a lower limit, from the viewpoint of easily forming a specified optical anisotropy layer, 5 mJ / cm is preferred. 2 The above, more preferably 10 mJ / cm 2 above.

[0285] In addition, the light irradiation in step 3 is preferably carried out at 15 to 70°C (preferably 15 to 50°C).

[0286] The light used for irradiation only needs to be light that is photosensitive to chiral reagent A. That is, there are no particular restrictions as long as the light used for irradiation is an activating ray or radiation that changes the helical torsional force of chiral reagent A. Examples include the bright-line spectrum of a mercury lamp, far-ultraviolet light represented by an excimer laser, extreme ultraviolet light, X-rays, ultraviolet light, and electron beams. Among these, ultraviolet light is preferred.

[0287] (Step 4) Step 4 is a step that performs a heat treatment on the composition layer after step 3. By performing this step, the orientation state of the liquid crystal compound changes in the region where the helical torsional force of the chiral reagent A in the light-irradiated composition layer changes.

[0288] The mechanism of this process will be described below using the accompanying drawings.

[0289] As mentioned above, if for Figure 7 In step 3, as shown in the composition layer 20, the orientation state of the liquid crystal compound is fixed in the first region 20A, while polymerization of the liquid crystal compound is difficult to occur in the second region 20B, and the orientation state of the liquid crystal compound is not fixed. Furthermore, the helical torsional force of the chiral reagent A changes in the second region 20B. If this helical torsional force of the chiral reagent A changes, compared to the state before light irradiation, the force required to twist the liquid crystal compound changes in the second region 20B. This will be explained in more detail.

[0290] As mentioned above, in Figure 6The composition layer 20 shown contains chiral reagent A and chiral reagent B, with a higher concentration of chiral reagent B than chiral reagent A. The helical direction of the chiral reagent A is left-handed, while the helical direction of the chiral reagent B is right-handed. Furthermore, the absolute value of the helical torsional force of chiral reagent A is the same as that of chiral reagent B. Therefore, the weighted average helical torsional force of the chiral reagents in the composition layer before light irradiation shows a positive value.

[0291] The above method is shown in Figure 8 In. Figure 8 In the middle, the vertical axis represents the helical torsional force of the chiral reagent (μm). -1 The value is calculated as "(mJ / cm²) × concentration of chiral reagent (mass%)", with the value further from zero indicating a greater torsional force on the helix. The horizontal axis represents "light irradiation (mJ / cm²)". 2 )".

[0292] First, the relationship between chiral reagent A and chiral reagent B in the composition layer before light irradiation corresponds to the point when the light irradiation amount is 0. If the helical torsional force (μm) of chiral reagent A is considered... -1 The absolute value of "concentration (mass%) of chiral reagent A" and "helical torsional force (μm) of chiral reagent B" are expressed as follows: -1 The absolute value of "(mass%) × concentration (%) of chiral reagent B" is compared to the value of "helical torsional force (μm) of chiral reagent B". -1 The concentration (mass%) of chiral reagent B is large. That is, the direction of the helical torsion that produces the torsion of chiral reagent B is (+). Therefore, as Figure 6 As shown, the liquid crystal compound is twisted and oriented along the thickness direction.

[0293] In this state, region 20B is illuminated, such as... Figure 8 As shown, when the helical torsional force of chiral reagent A decreases according to the amount of light irradiation, such as Figure 9 As shown, the weighted average helical torsion force of the chiral reagent in region 20B increases, and the right-handed helical torsion force becomes stronger. That is, regarding the helical torsion force of the torsion liquid crystal compound, the greater the irradiation dose, the greater the helical torsion force in the direction (+) of the helix twisted by the chiral reagent B.

[0294] Therefore, if the composition layer 20 after step 3, where the weighted average helical torsional force changes, is subjected to heat treatment to promote the reorientation of the liquid crystal compound, then as... Figure 10 As shown, in the second region 20B, the twist angle of the liquid crystal compound LC increases along the spiral axis extending along the thickness direction of the composition layer 20.

[0295] On the other hand, as described above, in the first region 20A of the composition layer 20, the liquid crystal compound is polymerized during step 3 and the orientation state of the liquid crystal compound is fixed, so the reorientation of the liquid crystal compound is not performed.

[0296] As described above, by implementing step 4, multiple regions with different orientation states of liquid crystal compounds are formed along the thickness direction of the composition layer.

[0297] The degree of distortion of the liquid crystal compound LC can be appropriately adjusted according to the type of chiral reagent A used and the exposure amount in step 3, thereby achieving the specified distortion angle.

[0298] Furthermore, while the method of using a chiral reagent whose helical torsional force is reduced by light irradiation as chiral reagent A has been described above, it is not limited to this method. For example, a chiral reagent whose helical torsional force is increased by light irradiation can be used as chiral reagent A. In this case, the helical torsional force of chiral reagent A increases when it is irradiated by light, and the liquid crystal compound is twisted and oriented along the rotation direction of the chiral reagent A.

[0299] Furthermore, while the above description describes the simultaneous use of chiral reagent A and chiral reagent B, it is not limited to this method. For example, it is also possible to use two types of chiral reagent A. Specifically, it is also possible to simultaneously use a chiral reagent A1 that induces levorotation and a chiral reagent A2 that induces dextrorotation. Chiral reagent A1 and chiral reagent A2 can be chiral reagents that increase helical torsional force or chiral reagents that decrease helical torsional force, respectively. For example, it is possible to simultaneously use a chiral reagent that induces levorotation and whose helical torsional force increases upon light irradiation, and a chiral reagent that induces dextrorotation and whose helical torsional force decreases upon light irradiation.

[0300] The optimal conditions for heat treatment are selected based on the liquid crystal compound used.

[0301] Among them, the preferred heating temperature is the temperature at which heating is performed from the state of step 3. The range of 35 to 250°C is more common, the range of 50 to 150°C is even more common, the range of more than 50°C but less than 150°C is even more common, and the range of 60 to 130°C is especially common.

[0302] The heating time is typically between 0.01 and 60 minutes, with 0.03 to 5 minutes being more common.

[0303] Furthermore, there is no particular limitation on the absolute value of the weighted average helical torsion force of the chiral reagent in the composition layer after light irradiation, but the absolute value of the difference between the weighted average helical torsion force of the chiral reagent in the composition layer after light irradiation and the weighted average helical torsion force before light irradiation is preferably 0.05 μm. -1More preferably, the micrometer size is 0.05–10.0 μm. -1 More preferably, it is 0.1–10.0 μm. -1 .

[0304] (Step 5) Step 5 is a step following step 4, in which the composition layer is cured to fix the orientation state of the liquid crystal compound to form the first optical anisotropic layer and the second optical anisotropic layer. By performing this step, the orientation state of the liquid crystal compound in the composition layer is fixed, and as a result, the specified optical anisotropic layer can be formed.

[0305] There are no particular limitations on the curing method; examples include light curing and heat curing. Among these, light irradiation is preferred, and ultraviolet irradiation is more preferred.

[0306] Ultraviolet radiation is achieved using light sources such as ultraviolet lamps.

[0307] There are no particular limitations on the amount of light (e.g., ultraviolet radiation), but it is generally preferred to be 100–800 mJ / cm². 2 about.

[0308] <Other Components> The polarizer of the present invention may have other components besides the polarizer and optical anisotropy layer described above.

[0309] (Support body) The polarizer may have a support. As described above, the support may be included as a coating material for the polarizer forming composition, or it may be directly included in the polarizer.

[0310] As a support, a transparent support is preferred. Furthermore, a transparent support refers to a support with a visible light transmittance of 60% or more, preferably 80% or more, and more preferably 90% or more.

[0311] The support body can be a long, strip-shaped support (long strip support). There is no particular limitation on the length of the long strip support, but it is preferably 10m or more, and from a productivity point of view, 100m or more is preferred. Furthermore, there is no particular limitation on the length in the longitudinal direction, and lengths of 10,000m or less are common.

[0312] There is no particular limitation on the width of the long support body, but it is mostly between 150 and 3000 mm, and preferably between 300 and 2000 mm.

[0313] The support may contain various additives (e.g., optical anisotropy modifiers, wavelength dispersion modifiers, microparticles, plasticizers, UV protectants, degradation inhibitors, and stripping agents).

[0314] To improve the adhesion between the support and the layers disposed on the support, the surface of the support can be treated (e.g., glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, and flame treatment).

[0315] Furthermore, an adhesive layer (base coat) can be applied to the support.

[0316] The support body can also be a so-called pseudo support body.

[0317] Furthermore, the surface of the support can be directly subjected to friction treatment. That is, a support that has already undergone friction treatment can be used. There are no particular restrictions on the direction of friction treatment; the optimal direction should be appropriately selected based on the desired orientation of the liquid crystal compound.

[0318] Friction processing is a widely used method applied as a liquid crystal alignment process in LCDs (liquid crystal displays). Specifically, it involves rubbing the surface of a support in a specific direction using materials such as paper, gauze, felt, rubber, nylon fibers, or polyester fibers to achieve alignment.

[0319] In addition, as mentioned above, the support may have an orientation layer on its surface.

[0320] (Surface protective layer) Polarizers may have a surface protective layer. When the polarizer is used in an image display device, the surface protective layer is preferably disposed on the most visible side.

[0321] There are no particular limitations on the materials that constitute the surface protective layer; they can be inorganic or organic. Examples of surface protective layers include glass substrates and polymer films such as polyimide and cellulose acylates.

[0322] The surface of the protective layer may include one or more layers selected from a surface curing layer (hard coating) and a low-reflection layer that suppresses surface reflections generated at the air interface.

[0323] Furthermore, a polarizer can be formed by directly coating the polarizer forming composition onto the surface of the surface protective layer on the side opposite to the visible side.

[0324] There is no particular limitation on the thickness of the surface protective layer, but from the viewpoint of thinness, it is preferably 800 μm or less, more preferably 100 μm or less. There is no particular limitation on the lower limit, but it is preferably 0.1 μm or more.

[0325] For example, a glass substrate with a thickness of less than 100 μm that can be bent is preferred because it can give full play to the flexibility of organic EL display devices.

[0326] Furthermore, regarding glass substrates with a thickness of 100 μm or less, from the viewpoint of impact resistance, it is preferable to use adhesives or the like to bond resin films, such as (meth)acrylic resins, polyester resins like polyethylene terephthalate (PET), cellulose resins like triacetyl cellulose (TAC), and cyclic olefin resins like norbornene, as protective films onto the glass substrate. In particular, from the viewpoint of flexibility, it is preferable to bond polyethylene terephthalate (PET) onto the glass substrate, and further from the viewpoint of visibility, it is preferable to use polyethylene terephthalate (PET) with an in-plane retardation of 3000 to 10000 nm.

[0327] <Organic EL (Electroluminescent) Display Devices> The organic EL display device of the present invention has the above-described polarizer. The polarizer of the present invention can preferably be used as a circular polarizer.

[0328] Typically, polarizers are placed on the organic EL display panel (organic EL display element) of an organic EL display device. In the polarizer, the polarizer is positioned on the visible side.

[0329] An organic EL display panel is a component in which a light-emitting layer or multiple organic compound films, including a light-emitting layer, are formed between a pair of electrodes, namely an anode and a cathode. In addition to the light-emitting layer, it may also have a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a protective layer, etc., and each of these layers may have other functions. Various materials can be used to form each layer.

[0330] Example The following examples and comparative examples further illustrate the features of the present invention. The materials, amounts, proportions, processing contents, and processing steps shown in the following examples can be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limited by the specific examples shown below.

[0331] <Example 1> (Fabrication of the transparent support) The following composition was added to a mixing tank and stirred to prepare a cellulose acetate solution for use as a core-layer cellulose acylate doping solution.

[0332] ---------------------------------------------------------- Core layer cellulose acylate doped solution ---------------------------------------------------------- 100 parts by weight of cellulose acetate with a degree of acetyl substitution of 2.88 • 12 parts by weight of polyester compound B as described in the examples of Japanese Patent Application Publication No. 2015-227955 • 2 parts by mass of the following compound F • Dichloromethane (primary solvent) 430 parts by weight • Methanol (second solvent) 64 parts by weight ---------------------------------------------------------- Compound F [Chemical Formula 5] A cellulose acetate solution for use as an outer cellulose acylate doping solution was prepared by adding 10 parts by mass of the following matting agent solution to 90 parts by mass of the core cellulose acylate doping solution.

[0333] ---------------------------------------------------------- Matting solution ---------------------------------------------------------- • Silica particles with an average particle size of 20 nm (AEROSIL R972, manufactured by NIPPON AEROSIL CO.,LTD.) 2 parts by weight • Dichloromethane (primary solvent) 76 parts by mass • Methanol (second solvent) 11 parts by weight · 1 part by mass of the above-mentioned core layer cellulose acylate doped solution ---------------------------------------------------------- After filtering the core layer cellulose acylate doped solution and the outer layer cellulose acylate doped solution with filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm, the three layers of the core layer cellulose acylate doped solution and the outer layer cellulose acylate doped solutions on both sides are simultaneously cast from the casting port onto a roller at 20°C (with casting machine).

[0334] Next, with the solvent content in the film at approximately 20% by mass, the film was peeled off from the roller, and the two ends of the film in the width direction were fixed using a tenter frame clamp. The film was then stretched laterally at an elongation ratio of 1.1 and dried. Subsequently, a transparent support with a thickness of 40 μm was produced by conveying the obtained membrane between the rollers of a heat treatment apparatus for further drying, and this support was designated as cellulose acylated membrane A1.

[0335] (Formation of photoalignment film B1) The composition for forming the photo-aligned film (described later) was continuously coated onto the cellulose acylate film A1 using a wire rod. The support with the coated film was dried for 120 seconds using warm air at 140°C, followed by polarized ultraviolet irradiation of the coating film (using 10 mJ / cm²). 2 A photo-aligned film is formed by using an ultra-high pressure mercury lamp, thus obtaining a TAC (triacetyl cellulose) membrane with a photo-aligned film. The thickness of the photo-aligned film is 0.25 μm.

[0336] ---------------------------------------------------------- Composition for forming photo-aligned films ---------------------------------------------------------- • 100.00 parts by weight of the following polymer PA-1 • 8.25 parts by weight of the following acid-producing agent PAG-1 • 0.6 parts by weight of the following stabilizer DIPEA · Xylene 1126.60 parts by weight 125.18 parts by weight of methyl isobutyl ketone ---------------------------------------------------------- Polymer PA-1 (where the value recorded in each repeating unit represents the content (mass%) of each repeating unit relative to all repeating units.) [Chemical Formula 6] Acid-producing agent PAG-1 [Chemical Formula 7] stabilizer DIPEA [Chemical Formula 8] (The fabrication of a polarizer) A polarizer forming composition comprising the following components is continuously coated onto the obtained optical alignment film using a wire bar, thereby forming a coating film.

[0337] Next, heat the coating at 140°C for 15 seconds and then cool it to room temperature (23°C).

[0338] Next, the coating is heated at 75°C for 60 seconds and then cooled to room temperature.

[0339] Then, LED (light emitting diode) lamps (center wavelength 365nm) were used at an illuminance of 200mW / cm². 2 A polarizer (thickness: 1.8 μm) was fabricated on the photo-aligned film by irradiating it for 2 seconds under the specified conditions. The transmittance of the polarizer in the wavelength region of 280–780 nm was measured using a spectrophotometer, and the average transmittance of visible light was 42%. The absorption axis of the polarizer is orthogonal to the width direction of the cellulose acylate film A1.

[0340] ---------------------------------------------------------- Composition of the composition for polarizer formation ---------------------------------------------------------- • 0.65 parts by mass of the above-mentioned first dichroic substance Dye-Cl • 0.15 parts by mass of the above-mentioned second dichroic substance Dye-M1 • 0.52 parts by mass of the above-mentioned third dichroic substance Dey-Y1 • 2.50 parts by weight of the following liquid crystal compound (L-1) • 1.50 parts by weight of the following rod-shaped liquid crystal compound (L-2) • Polymerization initiator IRGACUREOXE-02 (manufactured by BASF) 0.17 parts by weight • 0.01 parts by weight of the following surfactant (F-1) · Cyclopentanone 92.14 parts by weight · Benzyl alcohol 2.36 parts by weight ---------------------------------------------------------- Dichroic substance Dye-C1 [Chemical Formula 9] Dichroic substance Dye-M1 [Chemical Formula 10] Dichroic substance Dye-Y1 [Chemical Formula 11] Liquid crystal compound (L-1) (where the values ​​recorded in each repeating unit ("59", "15", "26") represent the content (mass%) of each repeating unit relative to all repeating units.) [Chemical Formula 12] Rod-shaped liquid crystal compound (L-2) [Chemical Formula 13] Surfactant (F-1) (where the values ​​recorded in each repeating unit represent the content (mass%) of each repeating unit relative to all repeating units.) [Chemical Formula 14] (Formation of an anisotropic optical layer) An optical anisotropic layer forming composition comprising a rod-shaped liquid crystal compound with the following composition was coated onto a polarizer fabricated as described above, and the resulting composition layer was heated at 60°C for 100 seconds. Furthermore, the absolute value of the weighted average helical torsional force of the chiral reagent in the composition layer was 0.03 μm. -1 .

[0341] Subsequently, under air (oxygen concentration: approximately 20% by volume), an irradiation dose of 52 mJ / cm was applied at 40°C. 2 The light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) is irradiated onto the composition layer to fix the orientation state of the liquid crystal compound in about half of the region on the polarizer side of the composition layer.

[0342] Furthermore, the obtained composition layer was heated at 60°C for 30 seconds.

[0343] Subsequently, the light from a metal halide lamp (manufactured by EYE GRAPHICS Co., Ltd.) with an irradiation dose of 500 mJ / cm² was emitted at 55°C under a nitrogen atmosphere. 2The circular polarizer 1 was fabricated by irradiating the composition layer to immobilize the liquid crystal compound in the air-side half region of the coating to form an optically anisotropic layer (thickness: 3.0 μm).

[0344] The optical anisotropy layer consists of two layers exhibiting different optical anisotropies. The polarizer-side layer (the first optical anisotropy layer) is a layer formed by fixing a rod-shaped liquid crystal compound with a twisted orientation along the thickness direction as the helical axis. The molecular axis of the liquid crystal compound in the layer is horizontal relative to the surface of the optical anisotropy layer. The Δnd of this layer is 282 nm, and the direction of the in-plane slow axis is 0° on the surface of the polarizer side and -26.5° on the surface of the air side (twist angle = 26.5°).

[0345] Furthermore, the air-side layer (the second optical anisotropy layer) in the optical anisotropy layer is a layer formed by fixing a rod-shaped liquid crystal compound with a twisted orientation along the thickness direction as the helical axis. The molecular axis of the liquid crystal compound in the layer is horizontal relative to the surface of the optical anisotropy layer. The Δnd of this layer is 140 nm, and the direction of the in-plane slow axis is -26.5° on the polarizer-side surface and -105.1° on the air-side surface (twist angle = 78.6°).

[0346] In addition, regarding the aforementioned angle, when observing the optical anisotropic layer from the polarizer side, the counterclockwise direction with the absorption axis of the polarizer as the reference (0°) is represented by a positive value.

[0347] ---------------------------------------------------------- Composition for forming optical anisotropic layers ---------------------------------------------------------- 80 parts by mass of the above-mentioned rod-shaped liquid crystal compound (L-2) 10 parts by weight of the following rod-shaped liquid crystal compound (B) 10 parts by mass of the following polymeric compound (C) Ethylene oxide modified trimethylolpropane triacrylate (V#360, manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.) 4 parts by weight Photopolymerization initiator (Irgacure 819, manufactured by BASF) 3 parts by weight The following left-handed tortuous chiral reagent (L1) is used in 0.59 parts by weight. The following right-handed tortuous chiral reagent (R1) is prepared in 0.39 parts by weight. Polymer (A) 0.08 parts by weight 0.50 parts by weight of the following polymer (B) 121 parts by weight of methyl isobutyl ketone 41 parts by weight of ethyl propionate ---------------------------------------------------------- Rod-shaped liquid crystal compound (B) [Chemical Formula 15] Polymerizable compounds (C) [Chemical Formula 16] Left-handed tortuous chiral reagent (L1) [Chemical Formula 17] Right-handed tortuous chiral reagent (R1) [Chemical Formula 18] Polymer (A) (where the values ​​recorded in each repeating unit represent the content (mass%) of each repeating unit relative to all repeating units.) [Chemical Formula 19] Polymer (B) (where the values ​​recorded in each repeating unit represent the content (mass%) of each repeating unit relative to all repeating units.) [Chemical Formula 20] (Preparation of the adhesive layer) Next, acrylate polymers were prepared according to the following steps.

[0348] In a reaction vessel equipped with a cooling pipe, a nitrogen inlet pipe, a thermometer, and a stirring device, butyl acrylate (95 parts by mass) and acrylic acid (5 parts by mass) were polymerized by solution polymerization to obtain an acrylate polymer (S1) with an average molecular weight of 2 million and a molecular weight distribution (Mw / Mn) of 3.0.

[0349] Next, using the obtained acrylate polymer (S1), an adhesive layer forming composition with the following composition was obtained.

[0350] ---------------------------------------------------------- Composition for forming adhesive layer ---------------------------------------------------------- • Acrylic polymer (S1) 100 parts by weight • 11.1 parts by weight of the following (A) multifunctional acrylate monomer • 1.1 parts by weight of the photopolymerization initiator (B) below • 1.0 part by weight of the following (C) isocyanate-based crosslinking agent • 0.2 parts by weight of the following (D) silane coupling agent ---------------------------------------------------------- (A) Multifunctional acrylate monomer: Tris(acryloyloxyethyl)isocyanurate, molecular weight = 423, trifunctional (manufactured by TOAGOSEI CO., LTD., product name "ARONIX M-315") (B) Photopolymerization initiator: a 1:1 mass ratio mixture of benzophenone and 1-hydroxycyclohexylphenyl ketone, manufactured by CibaSpecialty Chemicals Co., Ltd. as "Irgacure 500". (C) Isocyanate-based crosslinking agent: Trimethylolpropane-modified toluene diisocyanate (produced by Nippon Polyurethane Industry Co., Ltd. as "CORONATE L") (D) Silane coupling agent: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd. as “KBM-403”) The adhesive layer forming composition was applied to a release membrane that had been surface-treated with a silicone-based release agent using a die coater, and the resulting coating was dried at 90°C for 1 minute. Next, the resulting coating was irradiated with ultraviolet (UV) light under the following conditions to obtain the adhesive layer. The thickness of the adhesive layer was 15 μm.

[0351] -UV irradiation conditions- ·FUSION Co., Ltd.'s electrodeless H-tube lamps Illuminance 600mW / cm 2 Light intensity 150 mJ / cm2 • Regarding UV illuminance and light intensity, measurements were performed using “UVPF-36” manufactured by EYE GRAPHICS Co., Ltd.

[0352] The SAMSUNG GALAXY S5, equipped with an organic EL display panel, was disassembled. The touch panel with a circular polarizer was peeled off from the organic EL display device, and the circular polarizer was further peeled off from the touch panel, thus separating the organic EL display panel, touch panel, and circular polarizer. Next, the separated touch panel was re-bonded to the organic EL display panel. Furthermore, the optical anisotropy layer side of the circular polarizer 1, fabricated as described above, was bonded to the touch panel via an adhesive layer fabricated as described above to prevent air ingress. Moreover, the cellulose acylate film A1 of the circular polarizer 1 was peeled off, and the support side of the low-reflection surface film CV-LC5 (manufactured by FUJIFILM Corporation) was bonded to the peeled surface using an adhesive layer fabricated as described above, thereby fabricating the organic EL display device.

[0353] <Examples 2 to 4, Comparative Example 4> The amounts of the dichroic substances Dye-Y1, Dye-M1, Dye-C1, liquid crystal compound (L-1), and rod-shaped liquid crystal compound (L-2) in the polarizer forming composition were changed to the amounts by mass as described in Table 1. Otherwise, circular polarizers 2 to 4 and circular polarizer C4 were fabricated using the same method as in Example 1, and an organic EL display device was further fabricated.

[0354] <Examples 5-6> As shown in Table 1, the rod-shaped liquid crystal compound (L-2) was changed to a rod-shaped liquid crystal compound (L-3) or a rod-shaped liquid crystal compound (L-4). Otherwise, circular polarizers 5 to 6 were fabricated in the same manner as in Example 2, and an organic EL display device was further fabricated.

[0355] In addition, the rod-shaped liquid crystal compound (L-3) described in Table 1 below has the following structure.

[0356] [Chemical Formula 21] Furthermore, the rod-shaped liquid crystal compound (L-4) described in Table 1 below has the following structure.

[0357] [Chemical Formula 22] <Examples 7-8> The support for the composition for coating polarizers was changed to a low-reflection surface film CV-LC5 (manufactured by FUJIFILM Corporation). Otherwise, a circular polarizer 7 was fabricated using the same method as in Example 1.

[0358] Furthermore, the support for the composition for forming the polarizer was changed to glass with an AR film (AR glass 1) obtained by bonding an AR film (Dexerials, AR100; 91 μm) and a 50 μm thick glass substrate (SHOTT, D263) using an adhesive layer prepared in the manner described above. Otherwise, a circular polarizer 8 was prepared in the same manner as in Example 1.

[0359] A Samsung Galaxy S5 equipped with an organic EL display panel was disassembled. The touch panel with a circular polarizer was peeled off from the organic EL display device, and the circular polarizer was further peeled off from the touch panel, thus separating the organic EL display panel, touch panel, and circular polarizer. Next, the separated touch panel was re-bonded to the organic EL display panel. Then, the optical anisotropy layers of the circular polarizers 7 and 8, prepared as described above, were bonded to the touch panel via an adhesive layer prepared as described above to prevent air ingress, thereby fabricating the organic EL display device.

[0360] <Examples 9 to 11> The support for the composition for forming the coated polarizer was changed to commercially available COSMOSHINE SRF (film thickness 80 μm), commercially available cycloolefin film, or ZEONOR ZB12 (film thickness 50 μm) (manufactured by Zeon Corporation). Otherwise, circular polarizers 9 to 11 were fabricated using the same method as in Example 1.

[0361] The SAMSUNG GALAXY S5, equipped with an organic EL display panel, was disassembled. The touch panel with a circular polarizer was peeled off from the organic EL display device, and the circular polarizer was further peeled off from the touch panel, thus separating the organic EL display panel, touch panel, and circular polarizer. Next, the separated touch panel was re-bonded to the organic EL display panel, and the optical anisotropy layer side of the circular polarizers 9-11, prepared as described above, was further bonded to the touch panel via an adhesive layer prepared as described above to prevent air ingress. Furthermore, as described in Table 1, the support side of the low-reflection surface film CV-LC5 (manufactured by FUJIFILM Corporation) or the glass side of the AR glass 1 was bonded using the adhesive layer prepared as described above, thereby fabricating the organic EL display device.

[0362] <Comparative Example 1> (Preparation of cellulose acylated membrane A2) The components that will become the following cellulose acylate doped solution were added to a mixing tank and stirred, and the resulting composition was heated at 90°C for 10 minutes.

[0363] The resulting composition was then filtered using filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm to prepare the doped solution. The solid content concentration of the doped solution was 23.5% by mass, the amount of plasticizer added was in the ratio to cellulose acylate, and the solvent of the doped solution was dichloromethane / methanol / butanol = 81 / 18 / 1 (mass ratio).

[0364] ---------------------------------------------------------- Cellulose acylate doped solution ---------------------------------------------------------- Cellulose acylated compound (acetyl substitution degree 2.86, viscosity-uniform polymerization degree 310) 100 parts by weight Sugar ester compound 1 (chemical formula (S4)) 6.0 parts by mass Sugar ester compound 2 (chemical formula (S5)) 2.0 parts by mass Silica particle dispersion (AEROSIL R972, manufactured by NIPPON AEROSIL CO.,LTD.) 0.1 parts by weight Solvents (dichloromethane / methanol / butanol) ---------------------------------------------------------- [Chemical Formula 23] [Chemical Formula 24] The dopant solution prepared in the above manner was cast using a roller film casting machine. After the dopant solution was cast from the mold and brought into contact with a metal support cooled to 0°C, the resulting sheet (film) was peeled off. The roller was made of SUS steel.

[0365] After the film obtained by casting was peeled from the rollers, it was dried for 20 minutes in a tenter frame at 30–40°C using a clamping device that held both ends of the film. Subsequently, the film was post-dried by zone heating while being conveyed by rollers. The obtained film was then knurled and wound up. The resulting cellulose acylated film had a thickness of 40 μm, an in-plane retardation Re(550) of 1 nm at a wavelength of 550 nm, and a thickness retardation Rth(550) of 26 nm.

[0366] (Formation of an anisotropic optical layer) The cellulose acylated membrane A2 prepared in the above manner was continuously subjected to friction treatment. At this time, the length direction of the elongated membrane was parallel to the conveying direction, and the angle formed between the length direction of the membrane (conveying direction) and the rotation axis of the friction roller was set to 90°.

[0367] Using the cellulose acylate film A2, which has undergone the above-mentioned friction treatment, as a substrate, the above-mentioned optical anisotropic layer forming composition is coated on the cellulose acylate film A2 using a die coater. Otherwise, an optical anisotropic layer is formed on the cellulose acylate film A2 in the same manner as in Example 1, thereby producing an optical anisotropic film.

[0368] Next, the cellulose acylate film A2 side of the optical anisotropic film is bonded to the polarizer prepared in Example 1 using an adhesive layer prepared as described above, thereby producing a circular polarizer C1. In the obtained circular polarizer C1, the polarizer and the optical anisotropic layer are bonded together via the adhesive layer.

[0369] The SAMSUNG GALAXY S5, equipped with an organic EL display panel, was disassembled. The touch panel with a circular polarizer was peeled off from the organic EL display device, and the circular polarizer was further peeled off from the touch panel, thus separating the organic EL display panel, touch panel, and circular polarizer. Next, the separated touch panel was re-bonded to the organic EL display panel. Furthermore, the optical anisotropy layer side of the circular polarizer C1, prepared as described above, was bonded to the touch panel via an adhesive layer prepared as described above to prevent air ingress. Moreover, the cellulose acylate film A1 of the circular polarizer C1 was peeled off, and the support side of the low-reflection surface film CV-LC5 (manufactured by FUJIFILM Corporation) was bonded to the peeled surface using the adhesive layer prepared as described above, thereby fabricating the organic EL display device.

[0370] <Comparative Example 2> The following UV adhesive S1 was prepared.

[0371] ---------------------------------------------------------- UV adhesive S1 ---------------------------------------------------------- • CEL2021P (Daicel Corporation) 70 parts by weight · 20 parts by weight of 1,4-Butanediol diglycidyl ether 10 parts by weight of 2-ethylhexyl glycidyl ether • CPI-100P 2.25 parts by weight ---------------------------------------------------------- CEL2021P [Chemical Formula 25] CPI-100P [Chemical Formula 26] Using the aforementioned UV adhesive S1, the cellulose acylate film A2 of the optical anisotropic film prepared in Comparative Example 1 was bonded to the polarizer prepared in Example 1, and the resulting laminate was exposed to an illuminance of 1000 mJ to cure it, thereby producing a circular polarizer C2. In the obtained circular polarizer, the polarizer and the optical anisotropic layer were bonded together via a UV adhesive.

[0372] Next, a circular polarizer C2 was used instead of the circular polarizer C1, and an organic EL display device was fabricated following the same steps as in Comparative Example 1.

[0373] <Comparative Example 3> The alignment film coating solution with the following composition was continuously coated onto the polarizer prepared in Example 1 using a wire rod. The resulting coating was then dried with warm air at 80°C for 5 minutes, thereby obtaining a laminate containing an alignment film of polyvinyl alcohol (PVA) with a thickness of 0.5 μm. The resulting laminate sequentially comprises a cellulose acylate film A1 (transparent support), a photoalignment film, a polarizer, and an alignment film of PVA.

[0374] The surface of the oriented film side of the laminate produced in the above manner was continuously subjected to friction treatment. At this time, the length direction of the strip-shaped film is parallel to the conveying direction, and the angle formed between the length direction of the film (conveying direction) and the rotation axis of the friction roller is set to 90°.

[0375] ---------------------------------------------------------- Orientation film coating solution ---------------------------------------------------------- • 3.80 parts by weight of the following modified polyvinyl alcohol • Initiator Irg2959 0.20 parts by weight 70 parts by weight of water ·Methanol 30 parts by weight ---------------------------------------------------------- Modified polyvinyl alcohol [Chemical Formula 27] Using the above-mentioned friction-treated laminate as a substrate, the above-mentioned optical anisotropic layer forming composition was coated on the laminate using a die coater. Otherwise, an optical anisotropic layer was formed on the laminate in the same way as in Example 1, thereby producing a circular polarizer C3.

[0376] Next, a circular polarizer C3 was used instead of the circular polarizer C1, and an organic EL display device was fabricated following the same steps as in Comparative Example 1.

[0377] <Comparative Example 5> A circular polarizer C5, consisting of a cellulose acylate film, an alignment film, an optical anisotropy layer, and a polarizer layer, was fabricated using the method described in Example 17 of Japanese Patent No. 5753922.

[0378] The SAMSUNG GALAXY S5, equipped with an organic EL display panel, was disassembled. The touch panel with a circular polarizer was peeled off from the organic EL display device, and the circular polarizer was further peeled off from the touch panel, thus separating the organic EL display panel, touch panel, and circular polarizer. Next, the separated touch panel was re-bonded to the organic EL display panel. Furthermore, the support side of the circular polarizer C5, manufactured in the above manner, was bonded to the touch panel via an adhesive layer manufactured in the above manner to prevent air ingress. Moreover, the support side of the low-reflection surface film CV-LC5 (manufactured by FUJIFILM Corporation) was bonded to the polarizer surface using the adhesive layer manufactured in the above manner, thereby fabricating the organic EL display device.

[0379] In addition, the results of analyzing the depth direction composition of the circularly polarized plates obtained in Examples 1 to 11 using the TOF-SIMS method are as follows: Figure 2 As shown, at a specified depth, the distribution (line) representing the intensity of secondary ions originating from the components contained in the polarizer intersects with the distribution (line) representing the intensity of secondary ions originating from the components contained in the optical anisotropy layer.

[0380] On the other hand, in Comparative Examples 1 to 4, no such results were obtained. Figure 2 The diagram shows the result of the intersection of the distribution (line) of secondary ion intensity originating from the components contained in the polarizer and the distribution (line) of secondary ion intensity originating from the components contained in the optical anisotropy layer.

[0381] <Durability Evaluation> The fabricated organic EL display device was subjected to an environment of 95°C and relative humidity less than 10% for 1000 hours. Afterward, the display screen of the obtained organic EL display device was set to black, and the reflected light when a fluorescent lamp was incident on it from the front was observed. The display performance was evaluated according to the following criteria. The evaluation results are shown in Table 1 below.

[0382] <Evaluation Criteria> A: No visible black coloration and low reflectivity. B: Slightly visible coloration, but low reflectivity. C: Slightly visible coloration and high reflectivity D: Visibly colored and with high reflectivity. In Table 1, the column “Concentration of dichroic substance” indicates the content (mass%) of dichroic substance relative to the total mass of the polarizer.

[0383] In Table 1, the "Lamination Method" column indicates the bonding method between the polarizer and the optical anisotropic layer. "Laminated Coating" indicates a method of forming the optical anisotropic layer by coating the polarizer with a composition for forming the optical anisotropic layer in such a way that the polarizer and the optical anisotropic layer are arranged adjacent to each other. "PSA" indicates a method of bonding the polarizer and the optical anisotropic layer via an adhesive layer. "UV Bonding" indicates a method of bonding the polarizer and the optical anisotropic layer via a UV adhesive. "PVA Alignment Film" indicates a method of forming the optical anisotropic layer using a PVA alignment film, in which a PVA alignment film is disposed between the polarizer and the optical anisotropic layer.

[0384] The “Axis Offset (°)” column in Table 1 represents the angle formed between the absorption axis of the polarizer and the in-plane slow axis of the polarizer-side surface of the optical anisotropy layer (in other words, the in-plane slow axis of the polarizer-side surface of the first optical anisotropy layer).

[0385] In Table 1, “ΔlogP” represents the absolute value of the difference between the logP of the liquid crystal compound and the logP of the dichroic substance. Additionally, “ΔlogP” represents the smallest absolute value among the differences between the logP of each of the three dichroic substances (Dye-Y1, Dye-M1, and Dye-C1) and the logP of the second liquid crystal compound.

[0386] [Table 2]

[0387] As shown in Table 1, it was confirmed that the desired effect can be obtained by using the polarizer of the present invention.

[0388] In particular, according to Examples 5 and 6, it was confirmed that the effect is even better when ΔloP is 3.0 or above.

[0389] Symbol Explanation 10A, 10B - Polarizers; 12 - Polarizers; 14, 140 - Optical anisotropic layers; 16 - First optical anisotropic layer; 18 - Second optical anisotropic layer; 20 - Composite layer; 20A - First region; 20B - Second region.

Claims

1. A polarizer having: A polarizer formed using a composition comprising a first liquid crystal compound and a dichroic substance; and An optical anisotropic layer is disposed adjacent to the polarizer and formed using a composition containing a second liquid crystal compound. The content of the dichroic substance in the polarizer is less than 40% by mass relative to the total mass of the polarizer.

2. The polarizer according to claim 1, wherein, The content of the dichroic substance in the polarizer is less than 30% by mass relative to the total mass of the polarizer.

3. The polarizer according to claim 1 or 2, wherein, The angle between the absorption axis of the polarizer and the in-plane slow axis on the surface of the polarizer side of the optical anisotropy layer is within 1°.

4. The polarizer according to claim 1 or 2, wherein, The optical anisotropic layer is a layer formed by fixing a second liquid crystal compound with a twisted orientation oriented around the thickness direction as the helical axis.

5. The polarizer according to claim 1 or 2, wherein, The optical anisotropic layer has multiple layers formed by fixing a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis. The twist angles of the second liquid crystal compound in each of the multiple layers are different.

6. The polarizer according to claim 1 or 2, wherein, The optical anisotropic layer has multiple layers formed by fixing a second liquid crystal compound with a twisted orientation about the thickness direction as the helical axis. The twist angle of the second liquid crystal compound in the plurality of layers is in a different ratio to the thickness of the layer.

7. The polarizer according to claim 1 or 2, wherein, The optical anisotropy layer has a first optical anisotropy layer and a second optical anisotropy layer. The first optical anisotropic layer is disposed on the polarizer side. The first optical anisotropic layer and the second optical anisotropic layer are layers formed by fixing the second liquid crystal compound with a twisted orientation oriented around the thickness direction as the helical axis. The twisting direction of the second liquid crystal compound in the first optical anisotropic layer is the same as the twisting direction of the second liquid crystal compound in the second optical anisotropic layer. The twist angle of the second liquid crystal compound in the first optical anisotropic layer is 26.5 ± 10.0°. The twist angle of the second liquid crystal compound in the second optical anisotropic layer is 78.6 ± 10.0°. The in-plane slow axis on the surface of the first optical anisotropy layer on the side of the second optical anisotropy layer is parallel to the in-plane slow axis on the surface of the second optical anisotropy layer on the side of the first optical anisotropy layer. The values ​​of the product of the refractive index anisotropy Δn1 and the thickness d1 of the first optical anisotropy layer, measured at a wavelength of 550 nm, Δn1·d1, and the product of the refractive index anisotropy Δn2 and the thickness d2 of the second optical anisotropy layer, measured at a wavelength of 550 nm, Δn2·d2, respectively satisfy the following equations (1) and (2). Equation (1) 252nm≤Δn1·d1≤312nm, Equation (2) 110nm≤Δn2·d2≤170nm.

8. The polarizer according to claim 1 or 2, wherein, When analyzing the composition of the polarizer in the depth direction using time-of-flight secondary ion mass spectrometry, the relationship between the maximum intensity Imax of the secondary ion intensity originating from the dichroic material and the intensity Isur1 of the secondary ion intensity originating from the dichroic material on the surface of the polarizer opposite to the optical anisotropic layer satisfies equation (3). Equation (3) 2.0≤Imax / Isur1.

9. The polarizer according to claim 1 or 2, wherein, The absolute value of the difference between the logP of the second liquid crystal compound and the logP of the dichroic substance is 3.0 or more.

10. An organic electroluminescent display device having a polarizer according to any one of claims 1 to 9.

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