Optical film, polarizing plate, composition for forming alignment film, and method for producing polarizing plate

Abstract

The present invention addresses the problem of providing an optical film having excellent ultraviolet absorbency, excellent alignment properties of a liquid crystal compound in an optically anisotropic layer, and excellent adhesion between an alignment film and the optically anisotropic layer. The optical film according to the present invention comprises an alignment film and an optically anisotropic layer disposed adjacent to the alignment film, the optically anisotropic layer being formed using a composition containing a liquid crystal compound, and the alignment film containing particles containing an ultraviolet absorber and a cured product of a polymerizable compound having a polymerizable group, the average particle diameter of the particles is 500 nm or less, and the maximum absorption wavelength of the ultraviolet absorber is within the range of 320-400 nm.

Description

Technical Field

[0001] The present invention relates to an optical film, a polarizing plate, a composition for forming an alignment film, and a method for producing a polarizing plate. Background Art

[0002] Optically anisotropic layers are used in various applications.

[0003] Specific uses of the optically anisotropic layer include expansion of the viewing angle and suppression of coloration in image display devices.

[0004] As the optically anisotropic layer, for example, a layer formed using a liquid crystal compound is proposed.

[0005] In addition, in an image display device, a layer containing a UV absorber is sometimes provided from the viewpoint of durability of an optical laminate (optical film) including an optical anisotropic layer. For example, Patent Document 1 discloses an optical laminate (optical film) having a positive A layer and a UV absorbing layer in contact with the positive A layer. It is also disclosed that the UV absorbing layer is an oriented film and the positive A layer contains a liquid crystal compound.

[0006] Previous technical literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2021-189224 Summary of the invention

[0009] Technical issues to be solved by the invention

[0010] Patent Document 1 describes a method of using a molecular ultraviolet absorber as the ultraviolet absorber contained in the ultraviolet absorbing layer.

[0011] The present inventors have found that when an alignment film containing a UV absorber is formed with reference to the technique described in Patent Document 1 and an optically anisotropic layer containing a liquid crystal compound is formed on the alignment film, the adhesion between the alignment film and the optically anisotropic layer may be insufficient.

[0012] Furthermore, in the optically anisotropic layer formed on the alignment film, the alignment property of the liquid crystal compound contained in the optically anisotropic layer is also required to be high.

[0013] Therefore, an object of the present invention is to provide an optical film having excellent ultraviolet absorption, excellent alignment of a liquid crystal compound in an optically anisotropic layer, and excellent adhesion between an alignment film and an optically anisotropic layer.

[0014] Furthermore, another object of the present invention is to provide a polarizing plate including an optical film, an alignment film-forming composition, and a method for producing the polarizing plate.

[0015] Means for solving technical problems

[0016] The present inventors have conducted intensive studies to solve the above problems and have found that the above problems can be solved by particles containing a specific ultraviolet absorber and having a specific particle size or less, and have completed the present invention. That is, they have found that the above problems can be solved by the following structure.

[0017] [1] An optical film comprising an alignment film and an optically anisotropic layer disposed adjacent to the alignment film,

[0018] The optically anisotropic layer is formed using a composition containing a liquid crystal compound.

[0019] The alignment film includes particles containing an ultraviolet absorber and a cured product of a polymerizable compound having a polymerizable group.

[0020] The average particle size of the above particles is 500 nm or less.

[0021] The maximum absorption wavelength of the ultraviolet absorber is within the range of 320 to 400 nm.

[0022] [2] The optical film according to [1], wherein

[0023] The maximum absorption wavelength is within the range of 360 to 400 nm.

[0024] [3] The optical film according to [1] or [2], wherein

[0025] The above liquid crystal compound has a polymerizable group.

[0026] The polymerizable groups of the liquid crystal compound and the polymerizable groups of the polymerizable compound are both free radical polymerizable groups, or

[0027] The polymerizable group contained in the liquid crystal compound and the polymerizable group contained in the polymerizable compound are both cationically polymerizable groups.

[0028] [4] The optical film according to any one of [1] to [3], wherein

[0029] The above particles have polymerizable groups.

[0030] The polymerizable groups of the particles and the polymerizable groups of the polymerizable compounds are both free radical polymerizable groups, or

[0031] The polymerizable group contained in the particles and the polymerizable group contained in the polymerizable compound are both cationically polymerizable groups.

[0032] [5] A polarizing plate comprising the optical film according to any one of [1] to [4] and a polarizer.

[0033] [6] A composition for forming an alignment film, comprising particles containing an ultraviolet absorber and a polymerizable compound having a polymerizable group,

[0034] The average particle size of the above particles is 500 nm or less.

[0035] The maximum absorption wavelength of the ultraviolet absorber is within the range of 320 to 400 nm.

[0036] [7] The composition for forming an alignment film according to [6], wherein

[0037] The maximum absorption wavelength is within the range of 360 to 400 nm.

[0038] [8] The composition for forming an alignment film according to [6] or [7], wherein

[0039] The above particles have polymerizable groups.

[0040] The polymerizable groups of the particles and the polymerizable groups of the polymerizable compounds are both free radical polymerizable groups, or

[0041] The polymerizable group contained in the particles and the polymerizable group contained in the polymerizable compound are both cationically polymerizable groups.

[0042] [9] A method for manufacturing a polarizing plate, comprising the following steps:

[0043] The composition for forming an alignment film according to any one of [6] to [8] is applied onto a support to form a first coating film, and the first coating film is subjected to an alignment treatment;

[0044] Forming a second coating film by applying a composition containing a liquid crystal compound on the first coating film subjected to the alignment treatment;

[0045] The first coating film and the second coating film are subjected to a curing treatment to form an alignment film and an optically anisotropic layer, thereby forming a laminate including the support, the alignment film and the optically anisotropic layer; and

[0046] The laminate and the polarizer are bonded together so that the optically anisotropic layer and the polarizer face each other, and the support is peeled off from the bonded product, thereby obtaining a polarizing plate including the polarizer, the optically anisotropic layer, and the oriented film.

[0047] Effects of the Invention

[0048] According to the present invention, an optical film having excellent ultraviolet absorption, excellent alignment of a liquid crystal compound in an optically anisotropic layer, and excellent adhesion between an alignment film and an optically anisotropic layer can be provided.

[0049] Furthermore, the present invention can also provide a polarizing plate including an optical film, an alignment film-forming composition, and a method for producing the polarizing plate. DETAILED DESCRIPTION

[0050] Hereinafter, the present invention will be described in detail.

[0051] Although the description of the constituent elements described below may be made based on representative embodiments of the present invention, the present invention is not limited to such embodiments.

[0052] The meaning of each description in this specification is shown below.

[0053] In the present specification, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0054] In this specification, Re(λ) and Rth(λ) represent the in-plane retardation and the retardation in the thickness direction at a wavelength λ, respectively. Unless otherwise specified, the wavelength λ is 550 nm.

[0055] In this specification, Re(λ) and Rth(λ) are values ​​measured at wavelength λ by AxoScan (manufactured by Axometrics). The average refractive index ((nx+ny+nz) / 3) and film thickness (d(μm)) are input into AxoScan to calculate

[0056] Slow axis direction (°)

[0057] Re(λ)=R0(λ)

[0058] Rth(λ)=((nx+ny) / 2-nz)×d.

[0059] In addition, R0(λ) is displayed as a numerical value calculated by AxoScan and means Re(λ).

[0060] 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=589 nm) as a light source. When measuring wavelength dependence, it can be measured by a multi-wavelength Abbe refractometer DR-M2 (manufactured by ATAGO CO., LTD.) in combination with an interference filter.

[0061] In addition, values ​​in the Polymer Handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. The following are examples of average refractive index values ​​of major optical films: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0062] Furthermore, the bonding direction of the divalent groups (e.g., -O-CO-) indicated in this specification is not particularly limited. 1 -L 2 -L 3 In the bonding of L 2 In the case of -O-CO-, if the bond to L 1 Set the position of the side to *1 and bond to L 3 The position of the side is set to *2, then L 2 It can be *1-O-CO-*2 or *1-CO-O-*2.

[0063] In this specification, “(meth)acrylate” means “acrylate” or “methacrylate”, “(meth)acryl” means “acryl” or “methacryl”, and “(meth)acryloyl” means “acryloyl” or “methacryloyl”.

[0064] <Optical film>

[0065] The optical film of the present invention includes an alignment film and an optically anisotropic layer disposed adjacent to the alignment film.

[0066] The characteristic points of the optical film of the present invention include the following: the oriented film comprises particles containing an ultraviolet absorber and a cured product of a polymerizable compound having a polymerizable group, the average particle size of the particles is less than 500 nm, and the maximum absorption wavelength of the ultraviolet absorber is within the range of 320 to 400 nm.

[0067] Although the detailed mechanism of why the optical film of the present invention has excellent ultraviolet absorption, the liquid crystal compound in the optically anisotropic layer has excellent orientation, and the orientation film and the optically anisotropic layer have excellent adhesion is not necessarily clear, the present inventors presume as follows.

[0068] The optical film of the present invention contains a UV absorber having a maximum absorption wavelength within the range of 320 to 400 nm, and therefore has excellent UV absorptivity.

[0069] On the other hand, generally, the polymerization of the polymerizable compound contained in the alignment film is carried out by ultraviolet rays in most cases. Therefore, when the alignment film contains an ultraviolet absorber, the polymerization of the polymerizable compound contained in the alignment film may be hindered. It can be considered that when the ultraviolet absorber molecules are uniformly dispersed in the alignment film, the polymerization of the polymerizable compound may be equally hindered in the entire alignment film.

[0070] Here, in the present invention, the ultraviolet absorber is contained in the particles, so it can be said that the polymerization initiation of the polymerizable compound in the region where the ultraviolet absorber does not exist nearby is not easily hindered. Therefore, it can be considered that the polymerization of the polymerizable compound is carried out in the alignment film, and the adhesion between the alignment film and the optical anisotropic layer is excellent.

[0071] In addition, the particles contained in the alignment film may also be present between the alignment film and the composition layer containing the liquid crystal compound formed on the alignment film. The particles generally do not have the ability to orient the liquid crystal compound, so it can be considered that the region where the particles are present at the interface sometimes becomes an orientation defect of the liquid crystal compound. Here, in the present invention, the average particle size of the particles contained in the alignment film is less than 500nm, so it can be considered that the region that becomes the orientation defect becomes smaller, and as a result, the orientation of the liquid crystal compound in the optically anisotropic layer is excellent.

[0072] Hereinafter, the structure included in the optical film will be described.

[0073] [Oriented film]

[0074] The alignment film included in the optical film of the present invention includes particles containing an ultraviolet absorber and a cured product of a polymerizable compound having a polymerizable group.

[0075] The method for obtaining the alignment film included in the optical film is not particularly limited, and preferably a method of applying the alignment film forming composition described in the latter section to a support, performing an alignment treatment and a curing treatment to obtain the alignment film. Therefore, the composition may include the components included in the alignment film forming composition described in the latter section, and components derived from the components included in the alignment film forming composition. The components other than the particles containing the ultraviolet absorber and the cured product of the polymerizable compound having a polymerizable group will be described in the latter section.

[0076] The alignment film may be a photo-alignment film that develops the alignment ability of a liquid crystal compound by light irradiation.

[0077] Next, the alignment film will be described.

[0078] (particle)

[0079] The particles contain a UV absorber.

[0080] The particles only need to contain the ultraviolet absorber, and may contain components other than the ultraviolet absorber. Furthermore, the particles may consist of only the polymer ultraviolet absorber.

[0081] In this specification, "particles containing ultraviolet absorbers" may be a form in which the particles contain low-molecular ultraviolet absorbers or a form in which the particles contain high-molecular ultraviolet absorbers. Low-molecular ultraviolet absorbers refer to compounds that have ultraviolet absorbing ability but do not have repeating units. High-molecular ultraviolet absorbers refer to high-molecular compounds that have repeating units including structures that have ultraviolet absorbing ability.

[0082] Furthermore, the state of the ultraviolet absorber contained in the particle is not particularly limited, and the ultraviolet absorber may be contained uniformly in the particle, or may be contained in a locally concentrated state in the particle. In the case where the ultraviolet absorber is contained in a locally concentrated state in the particle, there may be a plurality of concentrated portions of the ultraviolet absorber in the particle, or there may be only one concentrated portion of the ultraviolet absorber (e.g., core-shell structure).

[0083] The particles also preferably have a polymerizable group, and more preferably have a polymerizable group on the surface of the particles. Examples of the polymerizable group include radical polymerizable groups and cation polymerizable groups.

[0084] The details of the components contained in the particles will be described in the later section on the composition for forming an alignment film.

[0085] Furthermore, the average particle size of the particles is 500 nm or less.

[0086] The average particle size of the particles is preferably 20 to 500 nm, more preferably 30 to 450 nm, and further preferably 50 to 300 nm.

[0087] The average particle size of the particles is obtained by preparing a cross section of the optical film and averaging the equivalent circle diameters of the particle cross sections on the surface of the oriented film cross section. Specifically, first, the optical film is embedded with an epoxy resin. The embedded optical film is cut with an ultrathin slicer to obtain a sliced ​​sample for observation of the optical film.

[0088] For the obtained observation sample, in order to ensure the conductivity of the surface, the surface is subjected to carbon vapor deposition treatment as needed. Then, the obtained sliced ​​sample is attached in a wire grid shape, and the sample is observed by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). As a TEM device or a STEM device, for example, "JEM-F200" manufactured by JEOL Ltd. can be used. The magnification is appropriately changed according to the observation object, and multiple parts are observed while changing the observation area.

[0089] In the TEM image or STEM image obtained, the equivalent circle diameter of the particle cross section is measured. The particle cross section measured is measured until it becomes 100, and its arithmetic mean is set as the average particle size of the particle. In addition, when the particle cross section included in a TEM image or STEM image does not meet the above number, it is measured in other TEM images or STEM images until the above number is reached. In addition, in the TEM image or STEM image, when the image of the particle is unclear (for example, the difference between the transmittance of the cured product of the polymerizable compound of the alignment film and the electron beam of the particle is small), the energy dispersive X-ray spectrometer attached to the TEM device or STEM device can be used for element mapping, and the particle size of the particle is measured by checking with the TEM image or STEM image.

[0090] Furthermore, the maximum absorption wavelength of the ultraviolet absorber contained in the particles is within the range of 320 to 400 nm. The maximum absorption wavelength of the ultraviolet absorber contained in the particles is preferably within the range of 360 to 400 nm.

[0091] The maximum absorption wavelength of the ultraviolet absorber contained in the particles can be measured using a spectrophotometer. More specifically, the alignment film is separated from the optical anisotropic layer, and the absorption spectrum of the alignment film is obtained using a spectrophotometer. In addition, the absorption spectrum of the layer other than the alignment film contained in the optical film can be measured in advance and compared with the absorption spectrum of the entire optical film to obtain the maximum absorption wavelength of the ultraviolet absorber contained in the particles.

[0092] The content of particles in the oriented film can be appropriately adjusted according to the particles used, but from the viewpoint of maintaining good orientation, it is preferably 0.1 to 30 mass %, more preferably 0.5 to 25 mass %, further preferably 1 to 20 mass %, particularly preferably 1 to 10 mass %, and most preferably 1 to 5 mass %, relative to the total mass of the oriented film.

[0093] (Cured product of polymerizable compound)

[0094] The cured product of the polymerizable compound is obtained by curing the polymerizable compound.

[0095] The polymerizable compound is a compound having a polymerizable group.

[0096] As the polymerizable group possessed by the polymerizable compound, free radical polymerizable group, cationic polymerizable group and anionic polymerizable group can be mentioned, preferably free radical polymerizable group or cationic polymerizable group. The polymerizable compound can have various types of polymerizable groups. For example, the polymerizable compound can be a compound having free radical polymerizable group and cationic polymerizable group.

[0097] Regarding the polymerizable compound, when the particles have polymerizable groups, it is preferred that the polymerizable groups of the particles and the polymerizable groups of the polymerizable compounds are both free radical polymerizable groups, or the polymerizable groups of the particles and the polymerizable groups of the polymerizable compounds are both cationic polymerizable groups. If the above requirements are met, the adhesion between the alignment film and the optically anisotropic layer is more excellent.

[0098] The details of the polymerizable compound will be described in detail in the later section on the composition for forming an alignment film.

[0099] The content of the cured product of the polymerizable compound in the alignment film is preferably 50 to 99.9% by mass, more preferably 60 to 99% by mass, further preferably 70 to 99% by mass, particularly preferably 80 to 99% by mass, and most preferably 85 to 99% by mass, based on the total mass of the alignment film.

[0100] The thickness of the alignment film is preferably 0.01 to 10 μm, more preferably 0.01 to 5 μm, and further preferably 0.01 to 1 μm.

[0101] [Optically anisotropic layer]

[0102] The optically anisotropic layer is a layer formed using a composition containing a liquid crystal compound.

[0103] The optically anisotropic layer is preferably a layer formed by fixing the orientation state of the liquid crystal compound. In the layer in which the orientation state of the liquid crystal compound is fixed, optical properties derived from the liquid crystal compound are manifested, and the optical properties vary depending on the liquid crystal compound, and the orientation direction and orientation state of the liquid crystal compound. In the layer in which the orientation state of the liquid crystal compound is fixed, as long as the orientation state of the liquid crystal compound is fixed, the liquid crystal compound does not need to lose its liquid crystallinity.

[0104] The alignment state of the liquid crystal compound in the optically anisotropic layer can be appropriately selected depending on the application of the optical film.

[0105] Examples of the alignment state of the liquid crystal compound include nematic alignment (the same alignment state as a state in which a nematic phase is formed), smectic alignment (the same alignment state as a state in which a smectic phase is formed), and cholesteric alignment (the same alignment state as a state in which a cholesteric phase is formed).

[0106] The alignment direction of the liquid crystal compound may be parallel to the in-plane direction of the optical anisotropic layer (homogeneous alignment) or perpendicular to the in-plane direction of the optical anisotropic layer (perpendicular alignment). Furthermore, the alignment direction may be tilted from a direction parallel to or perpendicular to the in-plane direction of the optical anisotropic layer.

[0107] Furthermore, the orientation direction of the liquid crystal compound may change in the thickness direction of the optical anisotropic layer. For example, in the case where the liquid crystal compound is cholesterically oriented, the pitch of the cholesteric phase may change in the thickness direction of the optical anisotropic layer. Such an optical anisotropic layer is also called a pitch gradient layer. Furthermore, in the case where the liquid crystal compound is uniformly oriented, the orientation direction on one surface of the optical anisotropic layer may change from a direction parallel to the in-plane direction of the optical anisotropic layer to an inclined direction.

[0108] The optically anisotropic layer is formed by fixing the aligned state of the liquid crystal compound.

[0109] Here, the "fixed" state refers to a state in which the orientation of the liquid crystal compound in the oriented state is maintained. For example, the following state is preferred: under 0 to 50°C, or more severe conditions, within a temperature range of -30 to 70°C, there is no fluidity, and the orientation morphology will not change due to an external field or external force, and the fixed orientation state can be stably maintained. As such a fixation method, for example, as described in detail in the latter section, the following method can be cited: after orienting the polymerizable liquid crystal compound to form an oriented state, a curing treatment is performed to react the polymerizable group, thereby fixing the orientation state of the liquid crystal compound.

[0110] The thickness of the optically anisotropic layer is not particularly limited, but is preferably 0.5 to 10 μm.

[0111] Hereinafter, components contained in a composition containing a liquid crystal compound (hereinafter also referred to as a “liquid crystal composition”) will be described.

[0112] (Liquid Crystalline Compounds)

[0113] The type of the liquid crystal compound contained in the liquid crystal composition is not particularly limited.

[0114] Generally, liquid crystal compounds can be classified into rod-like types (rod-like liquid crystal compounds) and disc-like types (disc-like liquid crystal compounds) according to their shapes. Moreover, liquid crystal compounds can be classified into low molecular types and polymer types. Polymers generally refer to substances with a degree of polymerization of 100 or more (Polymer Physics·Phase Transition Dynamics, written by Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound may be used, but a rod-like liquid crystal compound or a disc-like liquid crystal compound is preferably used, and a rod-like liquid crystal compound is more preferably used. Two or more rod-like liquid crystal compounds, two or more disc-like liquid crystal compounds, or a mixture of a rod-like liquid crystal compound and a disc-like liquid crystal compound may be used.

[0115] The liquid crystal compound may be a polymerizable liquid crystal compound having a polymerizable group, that is, for example, a polymerizable rod-shaped liquid crystal compound or a polymerizable disc-shaped liquid crystal compound.

[0116] The type of polymerizable group possessed by the liquid crystal compound is not particularly limited, and is preferably a free radical polymerizable group or a cation polymerizable group, more preferably a polymerizable ethylenically unsaturated group or a ring polymerizable group, and further preferably a (meth)acryloyl group, a vinyl group, a styryl group, an allyl group or an epoxy group.

[0117] Examples of the rod-like liquid crystal compound include the liquid crystal compounds described in claim 1 of JP-A-11-513019 and paragraphs 0026 to 0098 of JP-A-2005-289980.

[0118] Examples of the discotic liquid crystal compound include liquid crystal compounds described in paragraphs 0020 to 0067 of JP-A-2007-108732 and paragraphs 0013 to 0108 of JP-A-2010-244038.

[0119] The content of the liquid crystal compound in the liquid crystal composition is not particularly limited, but is preferably 50% by mass or more, more preferably 70% by mass or more, relative to the total mass of the total solid content in the liquid crystal composition. The upper limit is not particularly limited, but is usually 95% by mass or less.

[0120] In addition, the solid content refers to a component that can form a solid product after the solvent is removed, and even if the property is liquid, it is also regarded as a solid content.

[0121] (Other polymerizable compounds)

[0122] The liquid crystal composition may contain other polymerizable compounds having one or more polymerizable groups.

[0123] Here, the polymerizable group of the other polymerizable compound is not particularly limited, and examples thereof include acryloyl, methacryloyl, vinyl, styryl, and allyl groups, among which acryloyl or methacryloyl is preferred.

[0124] As other polymerizable compounds, non-liquid crystal polymerizable compounds can be mentioned. Specifically, esters of polyols and (meth) acrylic acid (for example, ethylene glycol di(meth)acrylate, 1,4-cyclohexane diacrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate and polyester polyacrylate, etc.), vinylbenzene and its derivatives, vinyl sulfone, acrylamide and methacrylamide, etc. can be mentioned.

[0125] The content of such other polymerizable compounds when contained is preferably less than 50% by mass, more preferably 40% by mass or less, and further preferably 2 to 30% by mass, relative to the mass of the liquid crystal compound (the total mass of the liquid crystal compounds when there are multiple liquid crystal compounds).

[0126] (Chiral Reagent)

[0127] The liquid crystal composition may contain a chiral agent.

[0128] When the liquid crystal composition contains a chiral agent, the liquid crystal compound can be twisted and aligned along the helical axis. This alignment state is also called cholesteric alignment.

[0129] The type of chiral agent is not particularly limited, and any known chiral agent (e.g., "Handbook of Liquid Crystal Devices" compiled by the 142nd Committee of the Japan Society for the Promotion of Science, Chapter 3, Item 4-3, Chiral Agents for TN and STN, p. 199, 1989) can be used.

[0130] As a chiral agent, a photosensitive chiral agent (hereinafter, also referred to as "chiral agent A") whose helical twisting force changes by light irradiation can be used. Chiral agent A can be liquid crystalline or non-liquid crystalline. Chiral agent A usually contains an asymmetric carbon atom in most cases. In addition, chiral agent A can be an axially asymmetric compound or a surface asymmetric compound that does not contain an asymmetric carbon atom.

[0131] The chiral agent A may have a polymerizable group.

[0132] The chiral reagent A may be a chiral reagent whose helical twisting force increases or decreases upon irradiation with light, but is preferably a chiral reagent whose helical twisting force decreases upon irradiation with light.

[0133] In the present specification, "increase and decrease of the helical twisting force" means the increase and decrease when the initial (before light irradiation) helical direction of the chiral agent A is set to "positive". Therefore, when the helical twisting force decreases and exceeds 0 by light irradiation and the helical direction becomes "negative" (that is, when a helix with a helical direction opposite to the initial (before light irradiation) helical direction is induced), it also corresponds to the "chiral agent with reduced helical twisting force".

[0134] The chiral agent A includes a so-called photoreactive chiral agent. The photoreactive chiral agent is a compound having a chiral site and a photoreactive site whose structure changes upon irradiation with light, for example, a compound that greatly changes the twisting force of a liquid crystal compound depending on the irradiation dose.

[0135] Among them, the chiral reagent A is preferably a compound having at least a photoisomerization site, and the photoisomerization site more preferably has a double bond capable of photoisomerization.

[0136] When the chiral agent has a photoisomerizable group, it is preferred because a pattern of a desired reflection wavelength corresponding to the emission wavelength can be formed by irradiating a photomask with activating light or the like after coating and alignment. The photoisomerizable group is preferably an isomerization site, an azobenzene site, a cinnamoyl site, an α-cyanocinnamoyl site, a stilbene site, or a chalcone site of a compound exhibiting photochromic properties. As specific compounds, compounds described in JP-A-2002-080478, JP-A-2002-080851, JP-A-2002-179668, JP-A-2002-179669, JP-A-2002-179670, JP-A-2002-179681, JP-A-2002-179682, JP-A-2002-338575, JP-A-2002-338668, JP-A-2003-313189, JP-A-2003-313292, etc. can be used.

[0137] The liquid crystal composition may contain two or more chiral agents A, or may contain at least one chiral agent A and at least one chiral agent whose helical twisting force does not change upon light irradiation.

[0138] The content of the chiral agent A in the liquid crystal composition is not particularly limited, but from the viewpoint of easy uniform orientation of the liquid crystal compound, it is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and further preferably 2.0% by mass or less relative to the total mass of the liquid crystal compound. The lower limit of the content of the chiral agent A is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and further preferably 0.05% by mass or more relative to the total mass of the liquid crystal compound.

[0139] (Polymerization initiator)

[0140] The liquid crystal composition may contain a polymerization initiator.

[0141] The polymerization reaction initiated by the polymerization initiator may be a thermal polymerization reaction using a thermal polymerization initiator or a photopolymerization reaction using a photopolymerization initiator, and a photopolymerization reaction is more preferred.

[0142] Examples of the photopolymerization initiator include α-carbonyl compounds (described in U.S. Pat. No. 2,367,661 and U.S. Pat. No. 2,367,670), acyloin ethers (described in U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (described in U.S. Pat. No. 2,722,512), polynuclear quinone compounds (described in U.S. Pat. No. 3,046,127 and U.S. Pat. No. 2,951,758), and a combination of a triaryl imidazole dimer and p-aminophenyl ketone (described in U.S. Pat. No. 3,549,367). , acridine and phenazine compounds (described in Japanese Patent Publication No. 60-105667 and U.S. Patent No. 4239850), oxadiazole compounds (described in U.S. Patent No. 4212970), acylphosphine oxide compounds (described in Japanese Patent Publication No. 63-040799, Japanese Patent Publication No. 5-029234, Japanese Patent Publication No. 10-095788 and Japanese Patent Publication No. 10-029997), or oxime ester compounds (for example, OXE-01 and OXE-02 manufactured by Omni or NCI-1919 manufactured by ADEKA Corporation).

[0143] When the liquid crystal composition contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 20% by mass, more preferably 0.4 to 8% by mass, based on the total mass of the solid content of the liquid crystal composition.

[0144] (Solvent)

[0145] The liquid crystal composition may contain a solvent.

[0146] As the solvent, an organic solvent is preferably used.

[0147] Examples of the organic solvent include amides (e.g., N,N-dimethylformamide), sulfoxides (e.g., dimethyl sulfoxide), hydrocarbons (e.g., toluene, hexane, etc.), alkyl halides (e.g., chloroform, dichloromethane, etc.), esters (e.g., methyl acetate, butyl acetate, ethyl propionate, etc.), ketones (e.g., acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, cyclopentanone, etc.), and ethers (e.g., tetrahydrofuran, 1,2-dimethoxyethane, etc.).

[0148] Among these organic solvents, esters and ketones are preferred.

[0149] The solvent may be used alone or in combination of two or more.

[0150] (Other ingredients)

[0151] The liquid crystal composition may contain components other than the above components, for example, a liquid crystal alignment controlling agent, an acid generator, a surfactant, a tilt angle controlling agent, an alignment film interface alignment agent, a plasticizer, a crosslinking agent, and the like.

[0152] [Other structures]

[0153] The optical film of the present invention may include other structures. As other structures, a support body may be mentioned. The details of the support body will be described later.

[0154] When the optical film further has a support, the support is preferably provided on the alignment film side of the optical film.

[0155] <Orientation film forming composition>

[0156] The alignment film forming composition of the present invention comprises particles containing an ultraviolet absorber and a polymerizable compound having a polymerizable group, the particles have an average particle size of 500 nm or less, and the maximum absorption wavelength of the ultraviolet absorber is within the range of 320 to 400 nm.

[0157] The alignment film can be formed by applying an alignment film-forming composition to a support and performing an alignment treatment and a curing treatment.

[0158] Hereinafter, components contained in the alignment film-forming composition will be described.

[0159] [particle]

[0160] The particles contained in the alignment film forming composition of the present invention contain an ultraviolet absorber, and the average particle size of the particles is 500 nm or less. Furthermore, the maximum absorption wavelength of the ultraviolet absorber is within the range of 320 to 400 nm.

[0161] The average particle size of the particles is measured by the above method. Specifically, in the above procedure, a thin film including at least an alignment film formed from an alignment film-forming composition is used instead of the above optical film to measure the average particle size.

[0162] The preferred embodiment of the average particle size of the particles is the same as the preferred embodiment of the average particle size of the above-mentioned particles.

[0163] The maximum absorption wavelength of the ultraviolet absorber contained in the particles is within the range of 320 to 400 nm. The maximum absorption wavelength of the ultraviolet absorber contained in the particles is preferably within the range of 360 to 400 nm.

[0164] The maximum absorption wavelength of the ultraviolet absorber contained in the particles is determined by the above method. More specifically, in the above procedure, an alignment film formed from the alignment film-forming composition is used to obtain an absorption spectrum of the alignment film using a spectrophotometer.

[0165] In addition, the maximum absorption wavelength of the ultraviolet absorber contained in the particles can be measured using a dispersion of the particles.

[0166] Hereinafter, the components contained in the particles will be described in detail.

[0167] (Ultraviolet light absorber)

[0168] The particles contained in the alignment film-forming composition of the present invention contain an ultraviolet absorber.

[0169] As described above, the ultraviolet absorber may be in the form of a low-molecular ultraviolet absorber or in the form of a high-molecular ultraviolet absorber.

[0170] The maximum absorption wavelength of the ultraviolet absorber is as described above.

[0171] As the structure having ultraviolet absorption ability included in the ultraviolet absorber, there is no particular limitation as long as it is a structure derived from a compound having a maximum absorption wavelength within the above range, and for example, a structure derived from a compound selected from the group consisting of benzophenone compounds, benzoxazinone compounds, anthracene compounds, benzotriazole compounds, indole compounds, methine compounds, benzodithiol compounds and hydroxyphenyltriazine compounds can be cited. Among them, a structure derived from a benzodithiol compound is preferred. Benzodithiol compounds can easily adjust the maximum absorption wavelength within the above preferred range.

[0172] As the ultraviolet absorber, a specific polymer including a repeating unit A having a structure represented by the following formula (A1) is preferred.

[0173] [Chemical formula 1]

[0174]

[0175] In formula (A1), Y 11 or Y 12 One of them represents a cyano group, and the other represents a cyano group, an alkylcarbonyl group which may have a substituent, an arylcarbonyl group which may have a substituent, a heterocyclic carbonyl group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, a carbamoyl group which may have a substituent, an aminosulfonyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent, or an aryloxycarbonyl group which may have a substituent.

[0176] V 11 Indicates *1-L V11 -*2. V 12 represents a hydrogen atom, a monovalent substituent, or *1-L V12 -*2.L V11 and L V12 Each independently represents a single bond or a divalent linking group. *1 represents the bonding position to the main chain of the specific polymer. *2 represents the bonding position to the benzene ring indicated in formula (A1).

[0177] R 11 and R 12 Each independently represents a hydrogen atom or a monovalent substituent.

[0178] As Y 11 and Y 12 The alkylcarbonyl group which may have a substituent is preferably an alkylcarbonyl group having 2 to 8 carbon atoms which may have a substituent, more preferably an acetyl group, an ethylcarbonyl group or a tert-butylcarbonyl group, further preferably an ethylcarbonyl group or a tert-butylcarbonyl group.

[0179] As Y 11 and Y 12 The arylcarbonyl group which may have a substituent is preferably an arylcarbonyl group having 2 to 14 carbon atoms which may have a substituent, more preferably a benzoyl group or a naphthoyl group, and still more preferably a benzoyl group.

[0180] As Y 11 and Y 12 The heterocyclic carbonyl group which may have a substituent is preferably a heterocyclic carbonyl group having 2 to 14 carbon atoms which may have a substituent, more preferably a 2-pyridinecarbonyl group or a 2-thiophenecarbonyl group, and still more preferably a 2-pyridinecarbonyl group. The heterocyclic ring constituting the heterocyclic carbonyl group may be either aromatic or non-aromatic.

[0181] As Y 11 and Y 12The alkylsulfonyl group which may have a substituent is preferably an alkylsulfonyl group having 1 to 4 carbon atoms which may have a substituent, and more preferably a methylsulfonyl group.

[0182] As Y 11 and Y 12 The arylsulfonyl group which may have a substituent is preferably an arylsulfonyl group having 6 to 10 carbon atoms which may have a substituent, and more preferably a benzenesulfonyl group.

[0183] As Y 11 and Y 12 The carbamoyl group which may have a substituent is preferably an unsubstituted carbamoyl group or an alkylcarbamoyl group having 1 to 9 carbon atoms which may have a substituent, more preferably an unsubstituted carbamoyl group or an alkylcarbamoyl group having 1 to 4 carbon atoms which may have a substituent, further preferably a carbamoyl group, an N-methylcarbamoyl group, an N,N-dimethylcarbamoyl group or an N-phenylcarbamoyl group.

[0184] As Y 11 and Y 12 The sulfamoyl group which may have a substituent is preferably an alkylsulfamoyl group having 1 to 7 carbon atoms which may have a substituent, a dialkylsulfamoyl group having 3 to 6 carbon atoms which may have a substituent, an arylsulfamoyl group having 6 to 11 carbon atoms which may have a substituent, or a heterocyclicsulfamoyl group having 2 to 10 carbon atoms which may have a substituent, and more preferably a sulfamoyl group, a methylsulfamoyl group, an N,N-dimethylsulfamoyl group, a phenylsulfamoyl group or a 4-pyridylsulfamoyl group.

[0185] As Y 11 and Y 12 The alkoxycarbonyl group which may have a substituent is preferably an alkoxycarbonyl group having 2 to 4 carbon atoms which may have a substituent, more preferably a methoxycarbonyl group, an ethoxycarbonyl group or a (t)-butoxycarbonyl group, further preferably a methoxycarbonyl group or an ethoxycarbonyl group, and particularly preferably an ethoxycarbonyl group.

[0186] As Y 11 and Y 12 The aryloxycarbonyl group which may have a substituent is preferably an aryloxycarbonyl group having 6 to 12 carbon atoms which may have a substituent, more preferably an aryloxycarbonyl group having 6 to 10 carbon atoms which may have a substituent, further preferably a phenoxycarbonyl group, 4-nitrophenoxycarbonyl group, 4-acetylaminophenoxycarbonyl group or 4-methylsulfonylphenoxycarbonyl group.

[0187] As Y 11 and Y 12 Examples of the substituent that each group represented by may have include an alkyl group, an alkoxy group, and an aryl group, and an alkoxy group is preferred.

[0188] Preferably Y 11 or Y 12 One of them represents a cyano group, and the other represents a cyano group, an alkylcarbonyl group which may have a substituent, an arylcarbonyl group which may have a substituent, a heterocyclic carbonyl group which may have a substituent, a carbamoyl group which may have a substituent, or an alkoxycarbonyl group which may have a substituent, and more preferably Y 11 or Y 12 One of them represents a cyano group, and the other represents a cyano group, an alkylcarbonyl group which may have a substituent, an arylcarbonyl group which may have a substituent, a carbamoyl group which may have a substituent, or an alkoxycarbonyl group which may have a substituent, and more preferably Y 11 or Y 12 One of them represents a cyano group, and the other represents a cyano group, an alkylcarbonyl group having 3 to 18 carbon atoms which may have a substituent, an arylcarbonyl group having 7 to 18 carbon atoms which may have a substituent, a carbamoyl group which may have a substituent, or an alkoxycarbonyl group having 3 to 18 carbon atoms which may have a substituent, and Y is particularly preferred 11 or Y 12 One of the groups represents a cyano group, and the other represents a cyano group, an ethylcarbonyl group, a tert-butylcarbonyl group, a benzoyl group or an ethoxycarbonyl group, and the most preferred group is Y 11 and Y 12 It represents cyano.

[0189] In formula (A1), V 11 Indicates *1-L V11 -*2.L V11 It represents a single bond or a divalent linking group.

[0190] As L V11 Examples of the divalent linking group represented by the present invention include -O-, -S-, -CO-, -COO-, and -CONR N -, alkylene, alkenylene, arylene, and a divalent linking group formed by combining them. As a divalent linking group formed by combining these, preferably -COO-alkylene-O- or -COO-alkylene-CO-, more preferably *1-COO-alkylene-O-*2 or *1-COO-alkylene-CO-*2. R N represents a hydrogen atom or a monovalent substituent.

[0191] The alkylene group may be linear, branched or cyclic, but is preferably linear.

[0192] The alkylene group has preferably 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms.

[0193] As L V11 , also preferably *1-X 1 -X 2-O-*2 or *1-X 1 -X 2 -CO-*2.X 1 and X 2 and X in formula (A3) 1 and X 2 The meanings are the same and the preferred aspects are also the same.

[0194] In formula (A1), V 12 represents a hydrogen atom, a monovalent substituent, or *1-L V12 -*2.L V12 It represents a single bond or a divalent linking group.

[0195] As V 12 Examples of the monovalent substituent represented by V include halogen atoms, mercapto groups, cyano groups, carboxyl groups, phosphoric acid groups, sulfo groups, hydroxyl groups, carbamoyl groups, sulfamoyl groups, nitro groups, alkoxy groups, aryloxy groups, acyl groups, acyloxy groups (-OCOR), acylamino groups, sulfonyl groups, sulfinyl groups, sulfonylamino groups, amino groups, ammonium groups, hydrazino groups, urea groups, imide groups, alkylthio groups, arylthio groups, alkenylthio groups, alkoxycarbonyl groups, aryloxycarbonyl groups, alkyl groups, and aryl groups. 12 The groups exemplified as monovalent substituents may further have substituents (for example, Y 11 and Y 12 substituents that may be present, etc.).

[0196] As V 12 , preferably cyano, nitro, hydroxy, alkoxy, aryloxy or acyloxy, more preferably alkoxy, aryloxy or acyloxy, further preferably alkoxy or acyloxy, especially preferably methoxy, ethoxy, isopropoxy, 2-ethylhexyloxy, 3,5,5-trimethylhexyloxy, acetoxy, propionyloxy, n-butyryloxy, tert-butyryloxy, 2-ethylhexanoyloxy, 3,5,5-trimethylhexanoyloxy or 4-(4-propylcyclohexyl)cyclohexylcarbonyloxy.

[0197] As L V12 The divalent linking group represented by V11 Represents a divalent linking group.

[0198] As V 12 , preferably a monovalent substituent or *1-L V12 -*2. And, in V 12 Indicates *1-L V12 -*2, L V12 It is also preferred to express with L V11 Same group.

[0199] *1 indicates the bonding position to the main chain of the specific polymer. *2 indicates the bonding position to the benzene ring indicated in formula (A1).

[0200] * The benzene ring explicitly shown in formula (A1) and bonded to the bonding position shown in 2 refers to the benzene ring constituting benzodithiol in formula (A1), which is V 11 、V 12 , R 11 and R 12 Directly bonded benzene ring.

[0201] Hereinafter, *1 and *2 will be described in detail by taking an example of the specific polymer.

[0202] For example, in V 11 Indicates *1-COO-(CH2)4-O-*2 and V 12 When represents a hydrogen atom, as an example of a specific polymer, there can be mentioned an embodiment having a repeating unit represented by the formula (PX) as the repeating unit A. 11 Indicates *1-COO-(CH2)4-O-*2, V 12 When *1-COO-(CH2)4-O-*2 is represented, an embodiment having a repeating unit represented by the formula (PY) as the repeating unit A can be given as an example of the specific polymer.

[0203] In formula (PX) and formula (PY), Y 11 , Y 12 , R 11 and R 12 Each of the symbols has the same meaning as in formula (A1).

[0204] [Chemical formula 2]

[0205]

[0206] In formula (A1), R 11 and R 12 Each independently represents a hydrogen atom or a monovalent substituent.

[0207] As R 11 and R 12 The monovalent substituent represented by is, for example, V 12 The monovalent substituent represented by is preferably an alkyl group which may have a substituent, and more preferably an unsubstituted alkyl group.

[0208] The alkyl group may be linear, branched or cyclic.

[0209] The alkyl group has preferably 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms.

[0210] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group (preferably a tert-butyl group).

[0211] Preferably R 11 or R 12 One of them represents a hydrogen atom, and the other represents a hydrogen atom or an alkyl group which may have a substituent, and more preferably R 11 or R 12 One of them represents a hydrogen atom, and the other represents an alkyl group which may have a substituent.

[0212] The repeating unit A preferably has a structure represented by formula (A2).

[0213] [Chemical formula 3]

[0214]

[0215] In formula (A2), V 21 Indicates *1-L V21 -*2. V 22 represents a hydrogen atom, a monovalent substituent, or *1-L V22 -*2.L V21 and L V22 Each independently represents a single bond or a divalent linking group. *1 represents the bonding position to the main chain of the specific polymer. *2 represents the bonding position to L indicated in formula (A2). a21 or L a22 bonding position.

[0216] L a21 and L a22 Each independently represents -O- or -CO-.

[0217] R 21 and R 22 Each independently represents a hydrogen atom or a monovalent substituent.

[0218] In formula (A2), V 21 Indicates *1-L V21 -*2.L V21 It represents a single bond or a divalent linking group.

[0219] As L V21 The divalent linking group represented by V11 The divalent linking group represented by is preferably -COO-alkylene-, and more preferably *1-COO-alkylene-*2.

[0220] In formula (A2), V 22 represents a hydrogen atom, a monovalent substituent, or *1-L V22 -*2.L V22It represents a single bond or a divalent linking group.

[0221] As L V21 The divalent linking group represented by V11 The divalent linking group represented by is preferably -COO-alkylene-, and more preferably *1-COO-alkylene-*2.

[0222] In V 22 Indicates *1-L V22 -*2, L V22 It is also preferred to express with L V21 Same group.

[0223] In formula (A2), L a21 and L a22 Each independently represents -O- or -CO-.

[0224] As L a21 and L a22 , preferably -O-. And, L a21 and L a22 It also preferably represents the same group.

[0225] In formula (A2), R 21 and R 22 With R 11 and R 12 The meanings are the same and the preferred aspects are also the same.

[0226] In the formula (A2), the meanings of *1 and *2 can refer to the meanings of *1 and *2 in the formula (A1).

[0227] The repeating unit A also preferably has a structure represented by formula (A3).

[0228] [Chemical formula 4]

[0229]

[0230] In formula (A3), V 31 represents a hydrogen atom, a monovalent substituent, or *1-L V31 -*2.L V31 represents a single bond or a divalent linking group. *1 represents the bonding position to the main chain of the specific polymer. *2 represents the bonding position to L explicitly indicated in formula (A3). a31 bonding position.

[0231] L a31 and L a32 Each independently represents -O- or -CO-.

[0232] R 31 and R 32R each independently represents a hydrogen atom or a monovalent substituent. 33 represents a hydrogen atom or a methyl group.

[0233] X 1 represents phenylene, -COO-, -CONH-, -O-, -CO- or -CH2-. 2 It represents a single bond or a divalent linking group.

[0234] V 31 With V 22 The meanings are the same and the preferred aspects are also the same.

[0235] L a31 and L a32 With L a21 and L a22 The meanings are the same and the preferred aspects are also the same.

[0236] R 31 and R 32 With R 11 and R 12 The meanings are the same and the preferred aspects are also the same.

[0237] In formula (A3), X 1 It represents phenylene, -COO-, -CONH-, -O- or -CO-.

[0238] As X 1 , preferably phenylene, -COO- or -CONH-, more preferably -COO-.

[0239] In formula (A3), X 2 It represents a single bond or a divalent linking group.

[0240] As X 2 The divalent linking group represented by V22 Represents a divalent linking group.

[0241] The repeating unit A also preferably has a repeating unit derived from a monomer having at least one polymerizable group selected from the group consisting of a (meth)acrylic acid group, a styryl group, a (meth)acrylamide group, and a vinyl ether group.

[0242] The content of the repeating unit A is preferably 10 to 100 mass % relative to the total mass of the specific polymer, more preferably 30 to 100 mass %, further preferably 40 to 100 mass %, particularly preferably 50 to 100 mass % from the viewpoint of more excellent effects of the present invention.

[0243] The specific polymer may have a repeating unit B in addition to the repeating unit A described above.

[0244] The repeating unit B is a repeating unit having a hydrophilic group.

[0245] Examples of the hydrophilic group include carboxylic acid groups and salts thereof; sulfonic acid groups and salts thereof; phosphoric acid groups and salts thereof; and nonionic hydrophilic groups such as hydroxyl groups, amino groups, betaine groups, ethylene glycol groups, polyethylene glycol groups, propylene glycol groups, polypropylene glycol groups, and amide groups.

[0246] The hydrophilic group is preferably at least one group selected from the group consisting of carboxylic acid groups and salts thereof, sulfonic acid groups and salts thereof, and hydroxyl groups, and more preferably at least one group selected from the group consisting of carboxylic acid groups and salts thereof, and sulfonic acid groups and salts thereof.

[0247] The number of the hydrophilic groups possessed by the repeating unit B may be one or two or more.

[0248] The repeating unit B is preferably a repeating unit derived from a monomer having a hydrophilic group and a polymerizable group.

[0249] The polymerizable group is preferably an ethylenically unsaturated group, more preferably a vinyl group, a (meth)acryloyl group, a styryl group or a maleimide group, and still more preferably a vinyl group or a (meth)acryloyl group.

[0250] Examples of the monomer having a carboxylic acid group or a salt thereof and a polymerizable group include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, 2-methacryloyloxymethylsuccinic acid, β-carboxyethyl acrylate, and salts thereof.

[0251] Examples of the monomer having a sulfonic acid group or a salt thereof and a polymerizable group include styrenesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, 3-sulfopropyl (meth)acrylate, bis-(3-sulfopropyl)-itaconate, and salts thereof.

[0252] Examples of the monomer having a phosphoric acid group or a salt thereof and a polymerizable group include vinylphosphonic acid, vinyl phosphate, bis(methacryloyloxyethyl)phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate, and salts thereof.

[0253] Examples of the monomer having a nonionic hydrophilic group and a polymerizable group include ethylenically unsaturated monomers having a (poly)ethyleneoxy group or a polypropyleneoxy group, such as 2-methoxyethyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, ethoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate (molecular weight: 200 to 1000) mono(meth)acrylate, and polyethylene glycol (meth)acrylate (molecular weight: 200 to 1000) mono(meth)acrylate; and ethylenically unsaturated monomers having a hydroxyl group, such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, and hydroxyhexyl (meth)acrylate.

[0254] The repeating unit B preferably has a repeating unit derived from at least one monomer selected from the group consisting of (meth)acrylic acid, itaconic acid, β-carboxyethyl (meth)acrylate, 2-(meth)acrylamide-2-methylpropanesulfonic acid, 3-sulfopropyl (meth)acrylate and salts thereof, and 2,3-dihydroxypropyl (meth)acrylate, more preferably has a repeating unit derived from at least one monomer selected from the group consisting of (meth)acrylic acid, itaconic acid, β-carboxyethyl (meth)acrylate, 2-(meth)acrylamide-2-methylpropanesulfonic acid, 3-sulfopropyl (meth)acrylate and salts thereof, and further preferably has a repeating unit derived from at least one monomer selected from the group consisting of (meth)acrylic acid, β-carboxyethyl (meth)acrylate, 2-(meth)acrylamide-2-methylpropanesulfonic acid, 3-sulfopropyl (meth)acrylate and salts thereof.

[0255] Examples of the salt of the carboxylic acid group, the sulfonic acid group and the phosphoric acid group include alkali metal salts (e.g., lithium salts, sodium salts and potassium salts), alkaline earth metal salts (e.g., barium salts and calcium salts) and ammonium salts, and alkali metal salts are preferred.

[0256] The repeating unit B is preferably a repeating unit represented by the formula (B).

[0257] [Chemical formula 5]

[0258]

[0259] In formula (B), R B represents a hydrogen atom or a methyl group. B represents a single bond or a divalent linking group. Z represents a hydrophilic group.

[0260] The hydrophilic group represented by Z is as described above.

[0261] As LB The divalent linking group represented by V11 The divalent linking group represented by is preferably -COO-, alkylene, -CONR N - and a divalent linking group formed by combining them. The substituent that the alkylene group may have is preferably a hydrophilic group that the repeating unit B has, and more preferably a hydroxyl group. N represents a hydrogen atom or a monovalent substituent.

[0262] When the specific polymer has a repeating unit B, the content of the repeating unit B is preferably 1 to 90 mass %, more preferably 1 to 70 mass %, further preferably 1 to 50 mass %, particularly preferably 5 to 40 mass %, and most preferably 7 to 30 mass % relative to the total mass of the specific polymer.

[0263] The specific polymer may have a repeating unit C in addition to the repeating unit A and the repeating unit B.

[0264] Examples of the repeating unit C include repeating units derived from alkyl (meth)acrylates.

[0265] The weight average molecular weight of the specific polymer is preferably 1,000 to 500,000, more preferably 1,000 to 100,000, further preferably 1,000 to 500,000, and particularly preferably 3,000 to 50,000.

[0266] The content of the ultraviolet absorber is preferably 5 to 100% by mass, more preferably 20 to 100% by mass, based on the total mass of the particles.

[0267] When the ultraviolet absorber is a polymer ultraviolet absorber, the content of the repeating unit having ultraviolet absorption ability is preferably 5 to 100% by mass, more preferably 20 to 100% by mass, based on all repeating units of the polymer ultraviolet absorber.

[0268] (Adhesive)

[0269] The particles may contain a binder as a component other than the ultraviolet absorber. The binder is not particularly limited, and examples thereof include acrylic resins, urethane resins, styrene resins, silicone resins, epoxy resins, ester resins, and diene polymers, and acrylic resins are preferred.

[0270] (Polymerizable Group)

[0271] The particle may have a polymerizable group, and preferably the particle has a polymerizable group on its surface. As the polymerizable group, for example, a free radical polymerizable group and a cationic polymerizable group can be cited. Examples of the free radical polymerizable group and the cationic polymerizable group are the same as the polymerizable compound described later.

[0272] In the case of the above-mentioned embodiment, it is sufficient that the polymerizable group exists in the particles, and the polymerizable group may be bonded to the ultraviolet absorber or to a component other than the ultraviolet absorber (for example, a binder).

[0273] Furthermore, methods for obtaining particles having polymerizable groups include a method of obtaining particles using an ultraviolet absorber having a polymerizable group, a method of obtaining particles using an adhesive having a polymerizable group, and a method of modifying the surface of particles not having a polymerizable group by a compound having a polymerizable group.

[0274] As the particles containing the ultraviolet absorber, commercially available products can be used.

[0275] Examples of commercially available products include Tinuvin (registered trademark, hereinafter the same) DW series (Tinuvin 400-DW, Tinuvin 477-DW, Tinuvin 479-DW, Tinuvin 49945-DW, Tinuvin 123-DW, Tinuvin 249-DW, etc.) manufactured by BASF and SE-2915E manufactured by Taisei Fine Chemical Co., Ltd.

[0276] As a method for obtaining particles containing ultraviolet absorbers, for example, the following method can be cited: when the ultraviolet absorber is a specific polymer, the specific polymer is pulverized by a ball mill, a roller mill, etc. to obtain a solid obtained by precipitating the specific polymer. As a method for precipitating the specific polymer, a method of dissolving it in a good solvent for the specific polymer and then contacting it with a poor solvent, and a method of removing the solvent component from a solution containing the specific polymer can be cited.

[0277] Furthermore, particles containing an ultraviolet absorber can be obtained by a method of preparing self-dispersible particles by a phase inversion emulsification method.

[0278] The method for producing the particles containing the ultraviolet absorber is not particularly limited, but particles obtained by a phase inversion emulsification method are preferred.

[0279] As a phase inversion emulsification method, for example, first, a UV absorber (e.g., a specific polymer) is dissolved or dispersed in a solvent (e.g., a water-soluble organic solvent, etc.). Next, a method of putting the UV absorber into water without adding a surfactant, stirring and mixing the mixture while neutralizing a group (e.g., an acidic group) that can form a salt of the UV absorber, and removing the solvent can be cited. According to the above sequence, an aqueous dispersion of particles containing the UV absorber can be obtained.

[0280] The content of the particles is preferably 0.1 to 30% by mass, more preferably 0.5 to 25% by mass, further preferably 1 to 20% by mass, particularly preferably 1 to 10% by mass, and most preferably 1 to 5% by mass, based on the total solid content of the alignment film-forming composition.

[0281] The particles may be used alone or in combination of two or more.

[0282] When two or more types of particles are used, the total amount thereof is preferably within the above-mentioned preferred content range.

[0283] [Polymerizable compound]

[0284] The polymerizable compound is a compound having a polymerizable group.

[0285] As the polymerizable group possessed by the polymerizable compound, free radical polymerizable group, cationic polymerizable group, anionic polymerizable group can be mentioned, preferably free radical polymerizable group or cationic polymerizable group. The polymerizable compound can have various types of polymerizable groups. For example, the polymerizable compound can be a compound having free radical polymerizable group and cationic polymerizable group.

[0286] As the radical polymerizable group, a generally known radical polymerizable group can be used, and an acryloyloxy group or a methacryloyloxy group is preferred.

[0287] As the cationically polymerizable group, generally known cationically polymerizable groups can be used, and examples thereof include alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic sulfide groups, spirocyclic orthoester groups, and vinyloxy groups, etc. Among them, alicyclic ether groups or vinyloxy groups are preferred, and epoxy groups, oxetanyl groups, or vinyloxy groups are more preferred.

[0288] The polymerizable compound may be a polymer having a repeating unit or a compound having no repeating unit.

[0289] When the polymerizable compound is a polymer having repeating units, examples of the polymerizable compound include polyvinyl alcohol resins, polyimide resins, (meth) acrylic resins, siloxane resins, and cycloolefin resins. Among them, vinyl alcohol resins or (meth) acrylic resins are preferred, and vinyl alcohol resins are more preferred.

[0290] Examples of the polymerizable compound that is a vinyl alcohol-based resin include polymerizable compounds represented by the following general formula (I).

[0291] [Chemical formula 6]

[0292] (I)

[0293]

[0294] In the general formula (I), L 11 It represents an ether bond, a carbamate bond, or an ester bond.

[0295] In the general formula (I), R t1 represents an alkylene group or an alkyleneoxy group.

[0296] In the general formula (I), L 12 Indicates bonded to R t1 and Q 11 of the connecting group.

[0297] In the general formula (I), Q 11 It represents a polymerizable group.

[0298] In the general formula (I), under the condition of x1+y1+z1=100, x1 is 10 to 99.9 mol%, y1 is 0.01 to 80 mol%, and z1 is 0 to 70 mol%. In addition, x1 is preferably 50 to 99.9 mol%. y1 is preferably 0.01 to 50 mol%, more preferably 0.01 to 20 mol%, further preferably 0.01 to 10 mol%, and particularly preferably 0.01 to 5 mol%. z1 is preferably 0.01 to 50 mol%.

[0299] In the general formula (I), k and h represent an integer of 0 or 1, respectively.

[0300] In the general formula (I), R t1 It preferably represents an alkylene group having 1 to 24 carbon atoms, and more preferably represents an alkylene group having 1 to 12 carbon atoms.

[0301] R t1 The methylene group contained in the can be selected from -O-, -CO-, -NH-, -NR 7 -(R 7 represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 15 carbon atoms), -S- and -SO2-, and is substituted by one or more thereof.

[0302] L 12 Preferably, it represents -O-, -S-, -CO-, -O-CO-, -O-CO-O-, -CO-O-CO-, -CONR-, -NR-, -NRCONR- or -NRCO-O- (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

[0303] -(L 12 ) h -Q 12Preferably, it represents a vinyl group, a vinyloxy group, an acryloyl group, a methacryloyl group, a crotonoyl group, an acryloyloxy group, a methacryloyloxy group, a crotonoyloxy group, a vinylphenoxy group, a vinylbenzoyloxy group, a styryl group, a 1,2-epoxyethyl group, a 1,2-epoxypropyl group, a 2,3-epoxypropyl group, a 1,2-iminoethyl group, a 1,2-iminopropyl group or a 2,3-iminopropyl group.

[0304] -(L 12 ) h -Q 12 More preferably, it represents a vinyl group, a vinyloxy group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, a crotonoyloxy group, a vinylbenzoyloxy group, a 1,2-epoxyethyl group, a 1,2-epoxypropyl group, a 2,3-epoxypropyl group, a 1,2-iminoethyl group, a 1,2-iminopropyl group, or a 2,3-iminopropyl group, and further preferably, it represents an acryloyl group, a methacryloyl group, an acryloyloxy group, or a methacryloyloxy group.

[0305] As an example in the case where the polymerizable compound is a vinyl alcohol-based resin, there can be mentioned a polymerizable compound represented by the following general formula (III).

[0306] [Chemical formula 7]

[0307] (III)

[0308]

[0309] In formula (III), L 31 It represents an ether bond, a carbamate bond, or an ester bond.

[0310] In formula (III), A 31 represents an arylene group which may have a substituent. Examples of the substituent which the arylene group may have include one or more groups selected from the group consisting of a halogen atom, an alkyl group, and an alkoxy group. 31 It is preferably an arylene group having 6 to 24 carbon atoms, or an arylene group having 6 to 24 carbon atoms substituted with one or more substituents selected from the group consisting of halogen, alkyl group having 1 to 4 carbon atoms, and alkoxy group having 1 to 4 carbon atoms.

[0311] In formula (III), R t1 Represents R t1 Same group.

[0312] In formula (III), L 32 Indicates that L 12 Same group.

[0313] In formula (III), Q 31 Indicates that Q 11 Same group.

[0314] In formula (III), under the condition of x2+y2+z2=100, x2 is 10 to 99.9 mol%, y2 is 0.01 to 80 mol%, and z2 is 0 to 70 mol%. In addition, x2 is preferably 50 to 99.9 mol%. y2 is preferably 0.01 to 50 mol%, more preferably 0.01 to 20 mol%, further preferably 0.01 to 10 mol%, and particularly preferably 0.01 to 5 mol%. z2 is preferably 0.01 to 50 mol%.

[0315] In formula (III), k1 and h1 represent an integer of 0 or 1, respectively.

[0316] In formula (III), f represents an integer of 0 or 1.

[0317] Furthermore, the hydrogen atom of the hydroxyl group contained in the repeating unit marked with the subscript x1 contained in the general formula (I), or the hydrogen atom of the hydroxyl group contained in the repeating unit marked with the subscript x2 contained in the general formula (III) is also preferably substituted by a repeating unit represented by the following formula (II).

[0318] [Chemical formula 8]

[0319] (II)

[0320]

[0321] In formula (II), R t2 It represents an alkyl group, or an alkyl group substituted by an alkoxy group, an allyl group, a halogen atom, a vinyl group, a vinyloxy group, an oxirane group, an acryloyloxy group, a methacryloyloxy group or a crotonoyloxy group.

[0322] In formula (II), W 21 represents an alkyl group or an alkoxy group. In addition, the alkyl group may be substituted by an alkoxy group, an aryl group, a halogen atom, a vinyl group, a vinyloxy group, an oxirane group, an acryloyloxy group, a methacryloyloxy group or a crotonyloxy group. In addition, the alkoxy group may be substituted by an alkyl group, an alkoxy group, an aryl group, a halogen atom, a vinyl group, a vinyloxy group, an oxirane group, an acryloyloxy group, a methacryloyloxy group or a crotonyloxy group.

[0323] In formula (II), q represents an integer of 0 or 1.

[0324] In formula (II), n represents an integer of 0 to 4, preferably 0 or 1, and more preferably 0.

[0325] In the case where the polymerizable compound represented by the general formula (I) or the general formula (III) contains a repeating unit having a group of the general formula (II), the repeating unit having a group of the general formula (II) is preferably in the range of 0.1 to 10 mol %, more preferably 0.1 to 5 mol %, relative to all repeating units of the compound represented by the general formula (I) or the general formula (III).

[0326] When the polymerizable compound is a vinyl alcohol-based resin, the polymerizable compounds described in Japanese Patent Application Laid-Open No. 09-152509 can also be preferably used.

[0327] In addition, regarding the synthesis method of the polymerizable compound represented by the general formula (I) or the general formula (III), reference can also be made to the above-mentioned publications.

[0328] When the alignment film is a photo-alignment film, the polymerizable compound preferably includes a repeating unit having a photo-alignment group. The photo-alignment group is preferably a group that generates at least one of dimerization and isomerization by the action of light.

[0329] Specific preferred examples of the group that dimerizes by the action of light include a group having a skeleton of at least one derivative selected from the group consisting of cinnamic acid derivatives, coumarin derivatives, chalcone derivatives, maleimide derivatives, and benzophenone derivatives.

[0330] On the other hand, as a group that isomerizes by the action of light, specifically, for example, a group having a skeleton of at least one compound selected from the group consisting of azobenzene compounds, stilbene compounds, spiropyran compounds, cinnamic acid compounds and hydrazono-β-ketoester compounds can be preferably mentioned.

[0331] In this photo-alignment group, a group having a skeleton of at least one derivative or compound selected from the group consisting of cinnamic acid derivatives, coumarin derivatives, chalcone derivatives, maleimide derivatives, azobenzene compounds, stilbene compounds and spiropyran compounds is preferred, among which a group having a skeleton of a cinnamic acid derivative or an azobenzene compound is more preferred, and a group having a skeleton of a cinnamic acid derivative (hereinafter also referred to as "cinnamoyl" for short) is further preferred.

[0332] As the polymerizable compound containing a repeating unit having a photo-alignment group, a copolymer having a repeating unit AX represented by the following formula (A) and a repeating unit BX represented by the following formula (B) is preferred.

[0333] [Chemical formula 9]

[0334]

[0335] In the above formula (A), R1 represents a hydrogen atom or a methyl group. 1 represents a divalent linking group. 2 , R 3 , R 4 , R 5 and R 6 Each independently represents a hydrogen atom or a substituent, R 2 , R 3 , R 4 , R 5 and R 6 Two adjacent groups in the group may be bonded to form a ring.

[0336] In the above formula (B), R 7 represents a hydrogen atom or a methyl group, L 2 represents a divalent linking group, and X represents a polymerizable group.

[0337] In formula (A), L 1 It represents a divalent linking group.

[0338] L 1 Preferably, it is a divalent linking group formed by combining at least two or more groups selected from the group consisting of a linear, branched or cyclic alkylene group having 1 to 18 carbon atoms which may have a substituent, an arylene group having 6 to 12 carbon atoms which may have a substituent, an ether group (-O-), a carbonyl group (-C(=O)-), and an imino group (-NH-) which may have a substituent.

[0339] L 1 It also preferably represents a divalent linking group including a nitrogen atom and a cycloalkane ring, and a part of the carbon atoms constituting the cycloalkane ring may be substituted with a heteroatom selected from the group consisting of nitrogen, oxygen and sulfur.

[0340] From the viewpoint of further improving the liquid crystal orientation, L in the above formula (A) 1 A divalent linking group represented by any of the following formulae (1) to (10) is also preferred.

[0341] [Chemical formula 10]

[0342]

[0343] In the above formulae (1) to (10), *1 represents a bonding position to a carbon atom constituting the main chain in the above formula (A), and *2 represents a bonding position to a carbon atom constituting a carbonyl group in the above formula (A).

[0344] Next, R in the above formula (A) 2 , R 3 , R 4 , R 5and R 6 In addition, as described above, R in the above formula (A) 2 , R 3 , R 4 , R 5 and R 6 It may not be a substituent but a hydrogen atom.

[0345] In the above formula (A), R 2 , R 3 , R 4 , R 5 and R 6 The substituents represented in one embodiment are preferably each independently a halogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a cyano group, an amino group, or a group represented by the following formula (11).

[0346] [Chemical formula 11]

[0347]

[0348] In the above formula (11), * represents the bonding position to the benzene ring in the above formula (A), and R 9 It represents a monovalent organic group.

[0349] As R 9 Examples of the monovalent organic group represented by include linear or cyclic alkyl groups having 1 to 20 carbon atoms.

[0350] As the linear alkyl group, an alkyl group having 1 to 6 carbon atoms is preferred, and specific examples thereof include a methyl group, an ethyl group, and an n-propyl group. Among them, a methyl group or an ethyl group is preferred.

[0351] The cyclic alkyl group is preferably an alkyl group having 3 to 6 carbon atoms, and specific examples thereof include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group. Among them, a cyclohexyl group is preferred.

[0352] In addition, as R in the above formula (11), 9 The monovalent organic group represented by may be a group in which a plurality of the above-mentioned linear alkyl groups and cyclic alkyl groups are combined directly or via a single bond.

[0353] R 4 A group represented by formula (11) is also preferred.

[0354] In formula (B), L 2It represents a divalent linking group.

[0355] In addition, as L 2 The divalent linking group represented by 1 The divalent connecting groups represented are the same connecting groups as described above.

[0356] In formula (B), X represents a polymerizable group.

[0357] Specific examples of X (polymerizable group) in the above formula (B) include epoxy groups, cyclohexyl oxide groups, oxetanyl groups, and functional groups having ethylenically unsaturated double bonds. Among them, at least one polymerizable group selected from the group consisting of the following formulae (X1) to (X4) is preferred.

[0358] [Chemical formula 12]

[0359]

[0360] In the above formulae (X1) to (X4), * represents the same as L in the above formula (B). 2 The bonding position, R 8 represents any one of a hydrogen atom, a methyl group and an ethyl group. In the above formula (X4), S represents a functional group having an ethylenically unsaturated double bond.

[0361] Among them, specific examples of the functional group having an ethylenically unsaturated double bond include a vinyl group, an allyl group, a styryl group, an acryloyl group, and a methacryloyl group, and an acryloyl group or a methacryloyl group is preferred.

[0362] The polymerizable compound including a repeating unit having a photo-alignment group may have other repeating units in addition to the repeating unit AX and the repeating unit BX.

[0363] Examples of the monomer (radical polymerizable monomer) that forms such other repeating units include acrylate compounds, methacrylate compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds.

[0364] The method for synthesizing the copolymer is not particularly limited, and the copolymer can be synthesized by, for example, mixing monomers forming the repeating unit AX, monomers forming the repeating unit BX, and monomers forming any other repeating units, and polymerizing the mixture in an organic solvent using a radical polymerization initiator.

[0365] The weight average molecular weight (Mw) of the copolymer is preferably 10,000 to 500,000, more preferably 10,000 to 100,000.

[0366] Here, the weight average molecular weight and the number average molecular weight are values ​​measured by gel permeation chromatography (GPC) under the conditions shown below.

[0367] Solvent (eluent): THF (tetrahydrofuran)

[0368] Device name: TOSOH HLC-8320GPC

[0369] Column: 3 TOSOH TSKgel Super HZM-H (4.6 mm x 15 cm) connected together

[0370] Column temperature: 40℃

[0371] Sample concentration: 0.1 mass%

[0372] Flow rate: 1.0ml / min

[0373] Calibration curve: Calibration curve of seven samples ranging from Mw=2800000 to 1050 (Mw / Mn=1.03 to 1.06) of TSK standard polystyrene manufactured by TOSOH CORPORATION

[0374] When the polymerizable compound includes a repeating unit having a photo-alignment group, the polymerizable compounds described in International Publication No. 2019 / 225632 and the polymerizable compounds described in International Publication No. 2020 / 179864 can also be appropriately used.

[0375] The content of the polymerizable compound is preferably 50 to 99.9% by mass, more preferably 60 to 99% by mass, further preferably 70 to 99% by mass, particularly preferably 80 to 99% by mass, and most preferably 85 to 99% by mass, based on the total solid content of the alignment film-forming composition.

[0376] The polymerizable compound may be used alone or in combination of two or more.

[0377] When two or more polymerizable compounds are used, the total amount thereof is preferably within the above-mentioned preferred content range.

[0378] [Solvent]

[0379] The alignment film-forming composition may contain a solvent.

[0380] Examples of the solvent include water and organic solvents.

[0381] As the organic solvent, an organic solvent which can be mixed with water in an arbitrary ratio is preferred.

[0382] In addition, the solvent is preferably selected so that the components contained in the particles are not dissolved.

[0383] Examples of the organic solvent include alcohol solvents, glycol solvents, glycol ether solvents, ketone solvents, amide solvents, and sulfur-containing solvents.

[0384] Examples of the alcohol solvent include methanol, ethanol, propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and tert-butanol.

[0385] Examples of the glycol-based solvent include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tetraethylene glycol.

[0386] Examples of the glycol ether-based solvent include ethylene glycol monoether.

[0387] Examples of the glycol monoethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, 1-methoxy-2-propanol, 2-methoxy-1-propanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, propylene glycol mono-n-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monobenzyl ether and diethylene glycol monobenzyl ether.

[0388] Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0389] Examples of the amide solvent include N,N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, formamide, N-methylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, and hexamethylphosphoric triamide.

[0390] Examples of the sulfur-containing solvent include dimethyl sulfone, dimethyl sulfoxide, and sulfolane.

[0391] The content of the solvent is preferably 60 to 99.9% by mass, more preferably 70 to 99% by mass, and further preferably 80 to 99% by mass, based on the total mass of the alignment film-forming composition.

[0392] The solvent may be used alone or in combination of two or more.

[0393] When two or more solvents are used, the total amount thereof is preferably within the above-mentioned preferred content range.

[0394] [Polymerization initiator]

[0395] The alignment film-forming composition may contain a polymerization initiator.

[0396] The polymerization initiator is selected according to the form of the polymerization reaction, and examples thereof include a thermal polymerization initiator and a photopolymerization initiator.

[0397] Examples of the thermal polymerization initiator include azo compounds and peroxide compounds.

[0398] Examples of the photopolymerization initiator include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, and combinations of triarylimidazole dimers and p-aminophenyl ketones.

[0399] When the alignment film forming composition contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 30% by mass, more preferably 0.5 to 20% by mass, based on the total solid content of the alignment film forming composition.

[0400] [additive]

[0401] The composition for forming an alignment film may contain other components in addition to the above, and as other components, for example, additives such as a refractive index modifier, an elastic modulus modifier, a crosslinking agent, a filler, an adhesion improver, a leveling agent, a surfactant, and a plasticizer can be cited. Among them, it is also preferred to use a crosslinking agent, and the crosslinking group of the crosslinking agent is preferably capable of reacting with the polymerizable group of the polymerizable compound contained in the composition for forming an alignment film.

[0402] <Polarizing Plate>

[0403] The polarizing plate of the present invention comprises the above-mentioned optical film and a polarizer.

[0404] The polarizing plate is a plate that converts unpolarized light into light of a certain polarization state, and specific examples thereof include a linear polarizing plate, an elliptical polarizing plate, and a circular polarizing plate. As the polarizing plate, a linear polarizing plate or a circular polarizing plate is preferred.

[0405] When the optical film included in the optical film is a λ / 4 plate, the polarizing plate of the present invention can be suitably used as a circular polarizing plate.

[0406] When the polarizing plate of the present invention is used as a circular polarizing plate, the optical film of the present invention is set as a λ / 4 plate, and the angle between the slow axis of the λ / 4 plate and the absorption axis of the polarizer described later is preferably 30 to 60°, more preferably 40 to 50°, further preferably 42 to 48°, and particularly preferably 45°.

[0407] Furthermore, the polarizing plate of the present invention can also be used as an optical compensation film for a liquid crystal display device of an IPS (In-Plane-Switching) mode or an FFS (Fringe-Field-Switching) mode.

[0408] When the polarizing plate of the present invention is used as an optical compensation film for a liquid crystal display device in IPS mode or FFS mode, the optical film of the present invention is set to a laminate of a positive A plate and a positive C plate, and the angle between the slow axis of the positive A plate and the absorption axis of the polarizer described later is preferably orthogonal or parallel. Specifically, the angle between the slow axis of the positive A plate and the absorption axis of the polarizer described later is more preferably 0 to 5° or 85 to 95°.

[0409] The “slow axis” of the λ / 4 plate or the positive A plate refers to the direction in which the refractive index is the largest within the plane of the λ / 4 plate or the positive A plate, and the “absorption axis” of the polarizer refers to the direction in which the absorbance is the highest.

[0410] [Polarizer]

[0411] The polarizer included in the polarizing plate of the present invention is not particularly limited as long as it has a function of converting light into specific linearly polarized light, and a conventionally known absorption-type polarizer or reflection-type polarizer can be used.

[0412] As the absorption type polarizer, an iodine polarizer, a dye polarizer using a dichroic dye, a polyene polarizer, etc. are used. Among the iodine polarizers and the dye polarizers, there are a coating type polarizer and a stretching type polarizer, and although both are applicable, a polarizer made by adsorbing iodine or a dichroic dye on polyvinyl alcohol and stretching is preferred.

[0413] Furthermore, as a method for obtaining a polarizer by stretching and dyeing a laminated film having a polyvinyl alcohol layer formed on a substrate, there can be cited the methods described in Japanese Patent No. 5048120, Japanese Patent No. 5143918, Japanese Patent No. 4691205, Japanese Patent No. 4751481 and Japanese Patent No. 4751486, and the known techniques related to these polarizers can also be preferably utilized.

[0414] As the reflective polarizer, a polarizer formed by laminating thin films having different birefringence, a wire grid polarizer, a polarizer formed by combining cholesteric liquid crystal having a selective reflection region and a quarter wave plate, or the like can be used.

[0415] Among them, from the perspective of better adhesion, the polarizer is preferably a polarizer containing a polyvinyl alcohol-based resin (a polymer containing -CH2-CHOH- as a repeating unit, especially at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymers).

[0416] The thickness of the polarizer is not particularly limited, but is preferably 3 to 60 μm, more preferably 3 to 30 μm, and further preferably 3 to 10 μm.

[0417] The polarizing plate of the present invention may have other structures in addition to the polarizer and the optical film.

[0418] Examples of other structures include a phase difference layer, an optical compensation film, a pressure-sensitive adhesive layer, an adhesive layer, a refractive index adjustment layer, a barrier layer, and a color tone adjustment layer.

[0419] <Method for producing polarizing plate>

[0420] The method for producing a polarizing plate of the present invention comprises the following steps: applying the above-mentioned composition for forming an alignment film on a support to form a first coating film, and subjecting the above-mentioned first coating film to an alignment treatment (hereinafter also referred to as "step 1");

[0421] A step of forming a second coating film by coating a composition containing a liquid crystal compound on the first coating film subjected to the alignment treatment (hereinafter also referred to as "step 2");

[0422] A step of curing the first coating film and the second coating film to form an alignment film and an optically anisotropic layer, thereby forming a laminate including the support, the alignment film and the optically anisotropic layer (hereinafter also referred to as "step 3"); and

[0423] A step of bonding the laminate and the polarizer so that the optically anisotropic layer and the polarizer face each other, and peeling the support from the obtained bonded product to obtain a polarizing plate including the polarizer, the optically anisotropic layer and the oriented film (hereinafter also referred to as "step 4").

[0424] Hereinafter, each step will be described.

[0425] [Process 1]

[0426] In step 1, the composition for forming an alignment film is applied onto a support to form a first coating film, and the first coating film is subjected to an alignment treatment.

[0427] The composition for forming an alignment film is as described above.

[0428] Examples of the support include a glass substrate and a polymer film.

[0429] Examples of materials for the polymer film include cellulose polymers; acrylic polymers such as polymethyl methacrylate; thermoplastic norbornene polymers; polycarbonate polymers; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such as polystyrene and acrylonitrile-styrene copolymers; polyolefin polymers such as polyethylene, polypropylene and ethylene-propylene copolymers; vinyl chloride polymers; amide polymers such as nylon and aromatic polyamide; imide polymers; sulfone polymers; polyethersulfone polymers; polyetheretherketone polymers; polyphenylene sulfide polymers; vinylidene chloride polymers; vinyl alcohol polymers; vinyl butyral polymers; aromatic ester polymers; polyoxymethylene polymers; epoxy polymers; or polymers obtained by mixing these polymers.

[0430] The support may be peeled off after forming the polarizing plate.

[0431] The thickness of the support is not particularly limited, but is preferably 5 to 200 μm, more preferably 10 to 100 μm, and further preferably 20 to 90 μm.

[0432] The coating method of the alignment film forming composition is not particularly limited, and a known method may be used. Examples of the coating method include air knife coating, curtain coating, roll coating, wire bar coating, gravure coating, and die coating.

[0433] The alignment treatment for the first coating film may be selected according to the type of the alignment film-forming composition.

[0434] When the alignment film formed by the alignment film forming composition is a photo-alignment film, the alignment treatment may include a light irradiation treatment. As the light irradiation treatment, an ultraviolet irradiation treatment may be included. The ultraviolet irradiation in the ultraviolet irradiation treatment may be non-polarized ultraviolet light or linearly polarized ultraviolet light. Furthermore, non-polarized ultraviolet light and linearly polarized ultraviolet light may be used together.

[0435] When the alignment film formed by the alignment film forming composition is not a photoalignment film, the alignment treatment may be, for example, a rubbing treatment. A known method may be used for the rubbing treatment, for example, a method of rubbing the surface of the first coating film multiple times in a constant direction with paper or cloth.

[0436] The direction of the rubbing treatment can be appropriately set according to the direction in which the liquid crystal compound is to be aligned.

[0437] In addition, before the first coating film is subjected to the alignment treatment, a treatment for removing the solvent contained in the alignment film forming composition may be performed. As a method for removing the solvent, a heat treatment may be mentioned. The temperature of the heat treatment may be appropriately set according to the type of the solvent contained in the alignment film forming composition, and is preferably 50 to 150°C.

[0438] [Process 2]

[0439] In step 2, a composition containing a liquid crystal compound (liquid crystal composition) is applied on the first coating film subjected to the alignment treatment to form a second coating film.

[0440] The liquid crystal composition is as described above.

[0441] The method for applying the liquid crystal composition is not particularly limited, and a known method can be applied. For example, the method described in the method for applying the alignment film-forming composition can be applied.

[0442] After the liquid crystal composition is applied, the solvent contained in the liquid crystal composition may be removed. The removal method is not particularly limited, and examples thereof include natural drying, reduced pressure treatment, and heating. The heating temperature may be appropriately set depending on the type of solvent, and may be 40 to 200°C.

[0443] Between step 2 and step 3 described later, a treatment for aligning the liquid crystal compound contained in the second coating film may be performed.

[0444] The treatment for aligning the liquid crystal compound is not particularly limited, and a known method can be used.

[0445] Examples of a method for aligning the liquid crystal compound include a method of applying an electric field to the second coating film and a method of heating to effect a phase transition to a liquid crystal phase. The heating method is preferred.

[0446] The heating temperature may be selected according to the liquid crystal compound contained in the second coating film, and is 40 to 200° C., preferably 90 to 150° C. The treatment for aligning the liquid crystal compound may be performed simultaneously with the heating for removing the solvent that may be contained in the second coating film.

[0447] Furthermore, when heating is performed, it is also preferred to perform a treatment at a lower temperature than the alignment treatment for the second coating film in order to stabilize the alignment direction of the liquid crystal compound after heating. The temperature is preferably 40 to 100°C, more preferably 40 to 80°C.

[0448] Furthermore, when the second coating film contains a chiral agent, ultraviolet irradiation may be performed in order to change the helical twisting force of the chiral agent. The ultraviolet irradiation is preferably performed in an oxygen-containing environment.

[0449] After the ultraviolet ray irradiation, the heat treatment may be performed again.

[0450] The ultraviolet rays of the above-mentioned irradiation refer to electromagnetic waves mainly including electromagnetic waves with a wavelength of 200 to 400 nm, preferably mainly including electromagnetic waves with a wavelength of 300 to 400 nm. The light source of the ultraviolet rays is not particularly limited and a known light source can be used, and an optical filter or the like can be used to irradiate ultraviolet rays including any wavelength region. As the light source of the ultraviolet rays, a high pressure mercury lamp, a metal halide lamp, and a light emitting diode (LED) can be cited.

[0451] The irradiation amount of ultraviolet rays can be appropriately set, but is preferably 5 to 100 mJ / cm 2 , more preferably 10 to 50 mJ / cm 2 .

[0452] [Process 3]

[0453] In step 3, the first coating film and the second coating film are cured to form an alignment film and an optically anisotropic layer, thereby forming a laminate including the support, the alignment film, and the optically anisotropic layer.

[0454] As the curing treatment, ultraviolet irradiation treatment is preferred.

[0455] The ultraviolet irradiation treatment is preferably carried out in an environment with a low oxygen concentration. The oxygen concentration of the ambient gas for the ultraviolet irradiation treatment is preferably 2000 volume ppm or less, more preferably 1000 volume ppm or less, and further preferably 500 volume ppm or less. As the lower limit of the oxygen concentration, 0 volume ppm or more can be cited.

[0456] The temperature of the first and second coating films during the ultraviolet irradiation treatment can be appropriately adjusted according to the components contained in the first and second coating films, and is preferably 150 to 120°C, and more preferably 60 to 100°C.

[0457] [Process 4]

[0458] In step 4, the laminate and the polarizer are bonded together so that the optically anisotropic layer and the polarizer face each other, and the support is peeled off from the bonded product to obtain a polarizing plate including the polarizer, the optically anisotropic layer, and the oriented film.

[0459] As the polarizer, the above-mentioned polarizers can be mentioned.

[0460] The method of laminating the polarizer and the laminate is not particularly limited, and examples thereof include a method of applying a pressure-sensitive adhesive or an adhesive to the surface of the laminate on the optically anisotropic layer side or the surface of the polarizer and laminating them.

[0461] As the adhesive and the binder, known adhesives and bonding agents can be used.

[0462] The support can be peeled off by a known method.

[0463] <Image display device>

[0464] The polarizing plate of the present invention can be suitably used in, for example, an image display device.

[0465] The display element used in the image display device is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter, abbreviated as “EL”) display panel, and a plasma display panel.

[0466] Among them, a liquid crystal cell or an organic EL display panel is preferred. That is, as an image display device to which the polarizing plate of the present invention is applied, a liquid crystal display device using a liquid crystal cell as a display element or an organic EL display device using an organic EL display panel as a display element is preferred.

[0467] The liquid crystal unit used in the liquid crystal display device is preferably a VA (Vertical Alignment) mode, an OCB (Optically Compensated Bend) mode, an IPS (In-Plane-Switching) mode, an FFS (Fringe-Field-Switching) mode or a TN (Twisted Nematic) mode, but is not limited to these.

[0468] The liquid crystal display device as an example of the image display device of the present invention is preferably a mode including, for example, a polarizer, the optical film of the present invention, and a liquid crystal cell in this order from the viewing side.

[0469] As an example of the image display device of the present invention, that is, an organic EL display device, for example, a preferred embodiment includes a polarizer, the optical film of the present invention, and an organic EL display panel in this order from the viewing side.

[0470] An organic EL display panel is a component in which a light-emitting layer or a plurality of organic compound thin films including a light-emitting layer is 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, and a protective layer, and each of these layers may have other functions. Various materials can be used to form each layer.

[0471] Example

[0472] Hereinafter, the present invention will be described in more detail based on examples.

[0473] The materials, amounts, ratios, treatment contents and treatment sequences shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[0474] <Production of optical films>

[0475] Hereinafter, a method for producing a support-attached optical film used in Example 1 will be described representatively.

[0476] [Production of Cellulose Acylate Film (Support)]

[0477] The following composition was put into a mixing tank and stirred, and further heated at 90°C for 10 minutes. Thereafter, the obtained composition was filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm, thereby preparing a doping liquid. The solid content concentration of the doping liquid was 23.5% by mass, the amount of the plasticizer (sugar ester compounds 1 and 2) added was a ratio relative to cellulose acylate, and the solvent of the doping liquid was dichloromethane / methanol / butanol = 81 / 18 / 1 (mass ratio).

[0478]

[0479] Sugar ester compounds 1 and 2

[0480] [Chemical formula 13]

[0481]

[0482] The dope solution prepared in the above-mentioned order was cast using a roll film casting machine. The dope solution was cast from the die so as to contact with a metal support cooled to 0° C., and then the obtained web (film) was peeled off. The roll was made of SUS.

[0483] After the web (film) obtained by casting was peeled off from the drum, it was dried in a tentering device at 30 to 40°C for 20 minutes using a tentering device in which both ends of the web were clamped by clips while conveying the film. Then, post-drying was performed by zone heating while conveying the web by rollers. After knurling the obtained web, a winding support (1) was prepared.

[0484] (Alkali saponification treatment)

[0485] The cellulose acylate film was passed through a dielectric heating roller at a temperature of 60° C. to raise the film surface temperature to 40° C. Thereafter, a bar coater was used to coat the film at a coating amount of 14 mL / m 2The alkaline solution with the following composition was applied to the tape surface of the film and conveyed under a steam-type far-infrared heater manufactured by NORITAKE CO., LIMITED heated to 110°C for 10 seconds. Then, 3 mL / m2 of pure water was applied using a bar coater. 2 Next, after water washing with a jet coater and dehydration with an air knife were repeated three times, the film was conveyed to a drying zone at 70° C. for 10 seconds for drying, thereby producing a cellulose acylate film after alkali saponification treatment.

[0486]

[0487] (Formation of the first coating film)

[0488] The alkali saponified surface of the cellulose acylate film was continuously coated with the alignment film forming composition O1 having the following composition using a #14 wire bar to form a coating film (first coating film). The first coating film was dried in hot air at 60°C for 60 seconds and further in hot air at 100°C for 120 seconds.

[0489]

[0490] Polymerizable compound P1 (wherein the numerical value described in each repeating unit represents the content (mol%) of each repeating unit relative to all repeating units.)

[0491] [Chemical formula 14]

[0492]

[0493] Ultraviolet light absorber U1: Tinuvin (registered trademark) 479-DW (manufactured by BASF)

[0494] The ultraviolet absorber U1 is a water dispersion containing ultraviolet absorber particles.

[0495] Photopolymerization initiator

[0496] [Chemical formula 15]

[0497]

[0498] [Formation of Optically Anisotropic Layer]

[0499] The first coating film prepared in the above was continuously subjected to friction treatment. At this time, the length direction of the long film was parallel to the conveying direction, and the angle between the film length direction (conveying direction) and the rotation axis of the friction roller was set to 78°. The film length direction (conveying direction) was set to 90°, and when observed from the film side, if the clockwise direction was represented by a positive value based on the film width direction (0°), the rotation axis of the friction roller was 12°. In other words, the position of the rotation axis of the friction roller was a position rotated 78° counterclockwise based on the film length direction.

[0500] The cellulose acylate film after the friction treatment was used as a support, and a liquid crystal composition L1 containing a rod-shaped liquid crystal compound of the following composition was coated using a die coater to form a composition layer (second coating film). In addition, the absolute value of the weighted average helical twisting force of the chiral agent in the composition layer was 0.0 μm -1 .

[0501]

[0502]

[0503] Rod-like liquid crystal compound (A)

[0504] [Chemical formula 16]

[0505]

[0506] Rod-like liquid crystal compound (B)

[0507] [Chemical formula 17]

[0508]

[0509] Polymerizable compound (C)

[0510] [Chemical formula 18]

[0511]

[0512] Left-handed chiral reagent (L2)

[0513] [Chemical formula 19]

[0514]

[0515] Right-twisted chiral reagent (R2)

[0516] [Chemical formula 20]

[0517]

[0518] Polymer (A) (content of left-side repeating unit: 39% by mass, content of right-side repeating unit: 61% by mass)

[0519] [Chemical formula 21]

[0520]

[0521] Next, the obtained composition layer was heated for 60 seconds at 95° C. The rod-like liquid crystal compound in the composition layer was aligned in a predetermined direction by the heating.

[0522] Then, the composition layer was irradiated with ultraviolet rays (irradiation dose: 25 mJ / cm 2 ).

[0523] Next, the obtained composition layer was heated at 95° C. for 10 seconds.

[0524] Thereafter, nitrogen was purged to adjust the oxygen concentration to 100 ppm by volume, and the composition layer was irradiated at 80° C. using a metal halide lamp (manufactured by EYE GRAPHICS Co., Ltd.) (irradiation dose: 500 mJ / cm 2 ) ultraviolet rays to form an optically anisotropic layer that fixes the orientation state of the liquid crystal compound. In this way, the optical film with support used in Example 1 was produced.

[0525] The optical film with support of Example 1 prepared in the above order was cut parallel to the rubbing direction, and the optical anisotropic layer was observed from the cross-sectional direction using a polarizing microscope. The thickness of the optical anisotropic layer was 2.7 μm, and the region (second region) with a thickness of 1.3 μm on the support side of the optical anisotropic layer was uniformly oriented without a twist angle, and the liquid crystal compound was twistedly oriented in the region (first region) with a thickness of 1.4 μm on the side opposite to the support of the optical anisotropic layer.

[0526] In addition, using Axoscan of Axometrics and its analysis software (Multi-Layer Analysi s), the optical properties of the optical film with support of Example 1 were obtained. The product of the in-plane refractive index difference Δn2 and the thickness d2 (Δn2d2) at a wavelength of 550 nm in the second region was 177 nm, the twist angle of the liquid crystal compound was 0°, and the orientation axis angle of the liquid crystal compound relative to the length direction of the strip was -11° on the support side and -11° on the side in contact with the first region.

[0527] In addition, the product of the in-plane refractive index difference Δn1 and the thickness d1 (Δn1d1) of the first region at a wavelength of 550nm is 180nm, the twist angle of the liquid crystal compound is 80°, and the orientation axis angle of the liquid crystal compound relative to the length direction of the strip is -11° on the side in contact with the second region and -91° on the air side.

[0528] The optical films with support used in Examples 2 to 5 were prepared in the same manner as the optical film with support of Example 1 except that the ultraviolet absorber U1 contained in the alignment film-forming composition was changed to the ultraviolet absorbers shown in the following table.

[0529] In Example 9, an optical film with a support was obtained in the same manner as in Example 4, except that an oriented film was formed without performing an alkali saponification treatment.

[0530] In addition, the addition amount of the ultraviolet absorber in each example was adjusted to be the same as the content of the ultraviolet absorber U1 relative to the content of the polymerizable compound P1.

[0531] The ultraviolet absorbers used in the examples are shown below.

[0532] (Ultraviolet absorber U2)

[0533] Tinuvin (registered trademark) 477-DW (manufactured by BASF)

[0534] The ultraviolet absorber U2 is a water dispersion containing ultraviolet absorber particles.

[0535] (Ultraviolet absorber U3)

[0536] SE-2915E (manufactured by Taisei Fine Chemical Co., Ltd.)

[0537] The ultraviolet absorber U3 is a water dispersion containing ultraviolet absorber particles.

[0538] (Ultraviolet absorber U4)

[0539] The ultraviolet absorber U4 was obtained by the following procedure.

[0540] First, referring to International Publication No. 2019 / 131572, a monomer M-1 having the following structure was synthesized.

[0541] [Chemical formula 22]

[0542]

[0543] In a 300 mL three-necked flask equipped with a stirring blade, a thermometer, a cooling tube, and a nitrogen inlet tube, 12.6 g of cyclohexanone and 12.6 g of 1-methoxy-2-propanol were placed and heated to 120° C. under a nitrogen stream. To the above contents, a mixed solution of 3.75 g of the above monomer M-1, 1.25 g of acrylic acid, 0.74 g of polymerization initiator V-601, and 25.2 g of cyclohexanone was added dropwise for 120 minutes. After reacting for 1 hour, a mixed solution of 0.8 g of polymerization initiator V-601 and 1.7 g of cyclohexanone was added, and the mixture was reacted for another 2 hours to obtain a solution containing a polymer having the following structure.

[0544] The weight average molecular weight of the obtained polymer was 7,200, and it was confirmed by NMR that the target compound was obtained.

[0545] [Chemical formula 23]

[0546]

[0547] Next, 54.8 g of the obtained polymer solution was weighed into a reaction vessel, and 31.8 g of isopropyl alcohol and 11.9 mL of a 1 mol / L NaOH aqueous solution were added, and the temperature in the reaction vessel was raised to 80° C. Next, 59.0 g of distilled water was added dropwise at a rate of 20 mL / min to disperse the polymer in water. After dispersion, the temperature in the reaction vessel was set to 80° C. at atmospheric pressure and maintained for 2 hours, then maintained at 85° C. for 2 hours, and then maintained at 90° C. for 2 hours. After maintaining the temperature, the inside of the reaction vessel was decompressed, and a total of 74.9 g of isopropyl alcohol and distilled water were distilled off to obtain an aqueous dispersion of ultraviolet absorber U4 having a solid content concentration (particle concentration) of 28.0% by mass.

[0548] In addition, the repeating units contained in the polymer contained in the ultraviolet absorber U4 and the ratio thereof are as follows.

[0549] [Chemical formula 24]

[0550]

[0551] (Ultraviolet absorber U5)

[0552] In a 300 mL three-necked flask equipped with a stirring blade, a thermometer, a cooling tube, and a nitrogen inlet tube, 12.6 g of cyclohexanone and 12.6 g of 1-methoxy-2-propanol were placed and heated to 120° C. under a nitrogen stream. A mixed solution of 3.75 g of the above-mentioned monomer M-1, 1.25 g of acrylic acid, 0.74 g of polymerization initiator V-601, and 25.2 g of cyclohexanone was added dropwise for 120 minutes. After reacting for 1 hour, a mixed solution of 0.8 g of V-601 and 1.7 g of cyclohexanone was added and reacted for a further 2 hours.

[0553] After the reaction, the reaction solution was added dropwise to an excess of hexane, and the precipitated polymer solid was recovered and air-dried at 60° C. to obtain 4.46 g of a polymer solid. 0.50 g of glycidyl methacrylate, 0.24 g of tetrabutylammonium bromide, 0.2 g of methylhydroquinone, and 50 mL of tetrahydrofuran were added to the obtained polymer solid to dissolve it, and the mixture was reacted at 80° C. for 8 hours.

[0554] The weight average molecular weight of the polymer was 9,800, and it was confirmed by NMR that the target compound was obtained.

[0555] Using the obtained polymer solution, an aqueous dispersion of the ultraviolet absorber U5 was obtained in the same procedure as that of the above-mentioned ultraviolet absorber U4.

[0556] In addition, the repeating units contained in the polymer contained in the ultraviolet absorber U5 and the ratio thereof are as follows.

[0557] [Chemical formula 25]

[0558]

[0559] The optical film with support used in Example 6 was obtained in the same manner as the optical film with support used in Example 1 except that the first coating film was formed on the cellulose acylate film not subjected to the alkali saponification treatment in the following procedure.

[0560] (Formation of the first coating film)

[0561] To 1-methoxy-2-propanol (1136 parts by mass), 100 parts by mass of the polymerizable compound P2, 0.80 parts by mass of the photoacid generator represented by the following structural formula, and 5.0 parts by mass of the ultraviolet absorber U6 were added to prepare an alignment film-forming composition O6.

[0562] -Polymerizable compound P2-

[0563] Regarding polymerizable compound P2, a polymerizable compound having the following repeating unit was synthesized with reference to International Publication No. 2019 / 225632. In addition, the ratio of the following repeating units is a mass ratio.

[0564] [Chemical formula 26]

[0565]

[0566] Photoacid generator

[0567] [Chemical formula 27]

[0568]

[0569] -Ultraviolet absorber U6-

[0570] In a 300 mL three-necked flask equipped with a stirring blade, a thermometer, a cooling tube, and a nitrogen inlet tube, 12.6 g of cyclohexanone and 12.6 g of 1-methoxy-2-propanol were placed and heated to 120° C. under a nitrogen stream. A mixed solution of 5.00 g of monomer M-1, 0.30 g of polymerization initiator V-601, and 25.2 g of cyclohexanone was added dropwise for 120 minutes. After reacting for 1 hour, a mixed solution of 0.4 g of V-601 and 1.7 g of cyclohexanone was added and further reacted for 2 hours to obtain a polymer with the following structure.

[0571] The weight average molecular weight of the polymer was 110,000, and it was confirmed by NMR that the target compound was obtained.

[0572] [Chemical formula 28]

[0573]

[0574] Then, for the solution that 7 mass parts of dispersant (HINOACT series T-8000, Kawaken Fine Chemicals Co., Ltd. manufacture) are dissolved in 60 mass parts of 1-methoxy-2-propanol, 15 mass parts of the above-mentioned polymer are added. The solution containing the polymer is dispersed for 72 hours with a ball mill. After dispersion, 75 mass parts of 1-methoxy-2-propanol are added to the dispersion liquid, and then the dispersion for 5 hours is carried out with a ball mill. The obtained solution is diluted to the desired solid content concentration, and the dispersion liquid of ultraviolet light absorber U6 is obtained.

[0575] The prepared composition for forming an oriented film O6 was applied to one side of the cellulose acylate film using a bar coater. After application, the film was dried on a hot plate at 123° C. for 62 seconds to remove the solvent, and then irradiated with ultraviolet rays (300 mJ / cm 2 , using an ultra-high pressure mercury lamp and a 365 nm bandpass filter), thereby forming a first coating film with a thickness of 0.5 μm. The first coating film thus obtained was irradiated with polarized ultraviolet light (7.9 mJ / cm 2 , using an ultra-high pressure mercury lamp) to form a photo-alignment film.

[0576] The optical film with support used in Example 7 was obtained in the same manner as the optical film with support used in Example 1 except that the first coating film was formed on the cellulose acylate film not subjected to the alkali saponification treatment in the following procedure.

[0577] (Formation of the first coating film)

[0578] To 1-methoxy-2-propanol (1136 parts by mass), 100 parts by mass of the polymerizable compound P3, 0.80 parts by mass of a thermal acid generator represented by the following structural formula, and 5.0 parts by mass of an ultraviolet absorber U6 were added to prepare an alignment film-forming composition O7.

[0579] -Polymerizable compound P3-

[0580] With reference to International Publication No. 2019 / 225632, a polymerizable compound having the following repeating units was synthesized. In addition, the ratio of the following repeating units is a mass ratio.

[0581] [Chemical formula 29]

[0582]

[0583] Thermal acid generator

[0584] [Chemical formula 30]

[0585]

[0586] The prepared composition for forming an oriented film O7 was applied to one side of the cellulose acylate film using a bar coater. After the application, the film was dried on a hot plate at 80°C for 5 minutes to remove the solvent, thereby forming a first coating film having a thickness of 0.5 μm. The first coating film thus obtained was irradiated with polarized ultraviolet light (10 mJ / cm 2 , using an ultra-high pressure mercury lamp), thereby forming a photo-alignment film.

[0587] The supported optical films used in Examples 8 and 10 were prepared in the same manner as the supported optical film of Example 7 except that the UV absorber U6 was changed to the UV absorbers shown in the following tables.

[0588] In addition, the addition amount of the ultraviolet absorber in Examples 8 and 10 was adjusted to be the same as the content of the ultraviolet absorber U6 relative to the content of the polymerizable compound P3.

[0589] (Ultraviolet absorber U7)

[0590] A dispersion of the ultraviolet absorber U7 was obtained by the same procedure as that for the ultraviolet absorber U6, except that the first dispersion time by the ball mill was set to 48 hours.

[0591] (Ultraviolet absorber U8)

[0592] 25 g of cyclohexanone was placed in a 300 mL three-necked flask equipped with a stirring blade, a thermometer, a cooling tube, and a nitrogen inlet tube, and heated to 120° C. under a nitrogen stream. A mixed solution of 4.75 g of the above-mentioned monomer M-1, 0.25 g of CYCLOMER M100 (manufactured by Daicel Corporation), 0.30 g of polymerization initiator V-601, and 25.2 g of cyclohexanone was dripped for 120 minutes. After reacting for 1 hour, a mixed solution of 0.4 g of V-601 and 1.7 g of cyclohexanone was added, and further reacted for 2 hours, and a polymer of the following structure was obtained.

[0593] The weight average molecular weight of the polymer was 12,500, and it was confirmed by NMR that the target compound was obtained.

[0594] [Chemical formula 31]

[0595]

[0596] Using the obtained polymer solution, a dispersion of the ultraviolet absorber U8 was obtained in the same procedure as that of the above-mentioned ultraviolet absorber U6.

[0597] The supported optical film used in Example 11 was obtained in the same manner as in Example 10, except that the liquid crystal composition L2 described below was used instead of the liquid crystal composition L1 in forming the optically anisotropic layer.

[0598]

[0599] Rod-like liquid crystal compound (D)

[0600] [Chemical formula 32]

[0601]

[0602] Photo cationic polymerization initiator (CPI-100P)

[0603] [Chemical formula 33]

[0604]

[0605] The support-attached optical film used in Example 12 was obtained in the same manner as in Example 10, except that the polymerizable compound P4 described below was used instead of the polymerizable compound P3.

[0606] Polymerizable compound P4

[0607] [Chemical formula 34]

[0608]

[0609] Furthermore, the optical films with support used in Comparative Examples 1 to 3 were prepared in the same manner as the optical film with support of Example 1 except that the ultraviolet absorber U1 contained in the alignment film-forming composition was changed to the ultraviolet absorbers shown in the following table.

[0610] In addition, the addition amount of the ultraviolet absorber in Comparative Examples 1 to 3 was adjusted to be the same as the content of the ultraviolet absorber U1 relative to the content of the polymerizable compound P1.

[0611] The ultraviolet absorbers used in the respective comparative examples are shown below.

[0612] (Ultraviolet absorber UC1)

[0613] A dispersion of the ultraviolet absorber UC1 was obtained by the same procedure as for the ultraviolet absorber U6, except that the first dispersion time by the ball mill was set to 6 hours.

[0614] (Ultraviolet absorber UC2)

[0615] Tinuvin (registered trademark) 477 (manufactured by BASF)

[0616] The optical film with support used in Comparative Example 4 was produced in the same manner as the optical film with support of Example 1 except that the polymerizable compound contained in the alignment film-forming composition was changed to polymer PC1 (KURARAY POVAL PVA-203).

[0617] The optical film with a support used in Comparative Example 5 was produced in the same manner as the optical film with a support of Example 1, except that a composition for forming an alignment film not containing the ultraviolet absorber U1 was used.

[0618] <Evaluation>

[0619] The following evaluations were performed on each of the produced support-attached optical films.

[0620] [Orientation]

[0621] The orientation of the optical anisotropic layer in the optical film with support was evaluated using a polarizing microscope. Specifically, the optical anisotropic layer in the optical film with support was observed at a magnification of 50 times with the polarizer of the polarizing microscope set to crossed Nicols. The observation was performed in 10 randomly selected fields of view (field size 1715×1280μm), and each field of view was classified into the following three.

[0622] I: No optical defects were observed.

[0623] II: Although optical defects were slightly observed, the level was not a problem in practical use.

[0624] III: A large number of optical defects were observed, which was a level problematic for practical use.

[0625] Based on the classification of the observed 10 viewing fields, the orientation was evaluated according to the following criteria.

[0626] A: All 10 fields of view are I or II

[0627] B: III is included in 10 fields of view, and the number of fields of view of III is 1 to 5 fields of view.

[0628] C: III is included in 10 fields of view, and the number of fields of view of III is 6 to 10 fields of view.

[0629] [Adhesion]

[0630] The optical anisotropic layer of the optical film with support was subjected to a 100-grid scratch test. In addition, the optical film with support of Example 9 was peeled off once between the support and the oriented film, and was bonded with an adhesive (manufactured by TO AGOSEI CO., LTD., ARON ALPHA 221F) so that the oriented film and the support were opposite to each other. The adhesive tape used in the peeling test was a scotch tape (registered trademark), and the peeling test was carried out three times. After the peeling test, the number of squares with more than half of the area peeled off was counted, and the evaluation was performed according to the following criteria.

[0631] AA: The number of peeled squares is 0 or more and less than 5

[0632] A: The peeled squares are more than 5 and less than 10

[0633] B: The number of peeled squares is more than 10 and less than 30

[0634] C: The number of peeled squares is more than 30 and less than 50

[0635] D: The number of peeled squares is more than 50

[0636] In addition, by a crosscut test, the support side of the peeled portion was cut with a microtome to expose a cross section, and the cross section was observed with a scanning electron microscope. As a result, in all the optical films with supports for which adhesion was evaluated, the oriented film remained on the support side. Therefore, it can be said that the peeling position when peeling occurred in the adhesion evaluation was not between the support and the oriented film.

[0637] [Ultraviolet absorption]

[0638] The ultraviolet absorption of the optical film with support was evaluated using a spectrophotometer. Specifically, the transmittance of the optical film with support at a wavelength of 380 nm was measured using a spectrophotometer UV3150 (manufactured by SHIMADZU CORPORATION). Based on the obtained transmittance, the ultraviolet absorption was evaluated according to the following criteria.

[0639] A: Less than 65%

[0640] B: 65% or more and less than 75%

[0641] C: 75% or more and less than 85%

[0642] D: 85% or more

[0643] <Results>

[0644] Table 1 shows the composition for forming an alignment film used in the production of each support-attached optical film and the evaluation results of the produced support-attached optical film.

[0645] In addition, in Table 1, the particle diameter is a value obtained by the above-mentioned method.

[0646] In Table 1, the column "Maximum absorption wavelength" of the ultraviolet absorber describes the maximum absorption wavelength of the ultraviolet absorber evaluated by the above-mentioned method according to the following categories.

[0647] A: Maximum absorption wavelength is 360~400nm

[0648] B: Maximum absorption wavelength is greater than 320nm and less than 360nm

[0649] [Table 1]

[0650]

[0651] From the results of Table 1, it was confirmed that the optical film of the present invention has excellent ultraviolet absorptivity, the liquid crystal compound in the optically anisotropic layer has excellent orientation, and the orientation film and the optically anisotropic layer have excellent adhesion.

[0652] On the other hand, in Comparative Example 1 in which the particle diameter was 500 nm or more, the orientation of the liquid crystal compound of the optically anisotropic layer was poor. Furthermore, in Comparative Examples 2 and 3 in which a non-particulate ultraviolet absorber was used, the adhesion was poor. Furthermore, in Comparative Example 4 in which a compound having no polymerizable group was used, the adhesion was poor. Furthermore, in Comparative Example 5 in which no ultraviolet absorber was used, the ultraviolet absorption was poor.

[0653] According to the comparison between Example 5 and Example 4, and the comparison between Example 10 and Example 7, it is confirmed that the adhesion is better when the particles have polymerizable groups, the polymerizable groups possessed by the particles and the polymerizable groups possessed by the polymerizable compounds are both free radical polymerizable groups, or the polymerizable groups possessed by the particles and the polymerizable groups possessed by the polymerizable compounds are both cationic polymerizable groups.

[0654] According to the comparison between Examples 11 and 12 and Example 10, it is confirmed that the adhesion is better when the liquid crystal compound has a polymerizable group, the polymerizable group of the liquid crystal compound and the polymerizable group of the polymerizable compound are both free radical polymerizable groups, or the polymerizable group of the liquid crystal compound and the polymerizable group of the polymerizable compound are both cationic polymerizable groups.

Claims

1. An optical film comprising an alignment film and an optically anisotropic layer disposed adjacent to the alignment film, The optically anisotropic layer is formed using a composition containing a liquid crystal compound. The alignment film includes particles containing an ultraviolet absorber and a cured product of a polymerizable compound having a polymerizable group. The average particle size of the particles is less than 500 nm. The maximum absorption wavelength of the ultraviolet absorber is in the range of 320 to 400 nm.

2. The optical film according to claim 1, wherein: The maximum absorption wavelength is in the range of 360 to 400 nm.

3. The optical film according to claim 1 or 2, wherein: The liquid crystal compound has a polymerizable group, The polymerizable group of the liquid crystal compound and the polymerizable group of the polymerizable compound are both radical polymerizable groups, or The polymerizable group included in the liquid crystal compound and the polymerizable group included in the polymerizable compound are both cationically polymerizable groups.

4. The optical film according to claim 1 or 2, wherein: The particles have polymerizable groups, The polymerizable groups of the particles and the polymerizable groups of the polymerizable compounds are both free radical polymerizable groups, or The polymerizable groups possessed by the particles and the polymerizable groups possessed by the polymerizable compounds are both cationically polymerizable groups.

5. A polarizing plate comprising the optical film according to claim 1 or 2 and a polarizer.

6. A composition for forming an alignment film, comprising particles containing an ultraviolet absorber and a polymerizable compound having a polymerizable group, The average particle size of the particles is less than 500 nm. The maximum absorption wavelength of the ultraviolet absorber is in the range of 320 to 400 nm.

7. The composition for forming an alignment film according to claim 6, wherein The maximum absorption wavelength is in the range of 360 to 400 nm.

8. The composition for forming an alignment film according to claim 6 or 7, wherein The particles have polymerizable groups, The polymerizable groups of the particles and the polymerizable groups of the polymerizable compounds are both free radical polymerizable groups, or The polymerizable groups possessed by the particles and the polymerizable groups possessed by the polymerizable compounds are both cationically polymerizable groups.

9. A method for manufacturing a polarizing plate, comprising the following steps: A step of applying the composition for forming an alignment film according to claim 6 or 7 onto a support to form a first coating film, and subjecting the first coating film to an alignment treatment; A step of forming a second coating film by coating a composition containing a liquid crystal compound on the first coating film subjected to the alignment treatment; a step of curing the first coating film and the second coating film to form an alignment film and an optically anisotropic layer, thereby forming a laminate including the support, the alignment film and the optically anisotropic layer; and The step of bonding the laminate and the polarizer so that the optically anisotropic layer and the polarizer face each other and peeling the support from the bonded product to obtain a polarizing plate including the polarizer, the optically anisotropic layer and the alignment film.

Images