JP6724297B2 - Method for producing optical laminate, method for producing circularly polarizing plate, and method for producing organic electroluminescence display device - Google Patents

Description

The present invention relates to a method for producing an optical laminate, an optical laminate produced by the production method, an optically anisotropic laminate, a circularly polarizing plate, and an organic electroluminescence display device.

A film having optical anisotropy such as a retardation plate is widely used as a constituent element of a display device such as a liquid crystal display device and an organic electroluminescence (hereinafter sometimes referred to as “organic EL”) display device. .. In particular, an optical laminate including a plurality of optically anisotropic layers having a desired retardation such as λ/4 and λ/2 is used as an antireflection film of an organic EL display device (for example, Patent Document 1). ).

As one of methods for obtaining an optically anisotropic layer, a method is known in which a compound capable of exhibiting a liquid crystal phase is molded into a solid film in the state of exhibiting the liquid crystal phase. As an example of such a method, a composition containing a polymerizable liquid crystal compound which is polymerizable and can exhibit a liquid crystal phase is applied to the surface of a suitable substrate to form a layer, and the polymerizable liquid crystal compound in the layer is formed. A method of forming a film having optical anisotropy by orienting and polymerizing while maintaining the oriented state. As a method for orienting a compound capable of exhibiting such a liquid crystal phase, an alignment regulating force is imparted to the surface of a substrate, a composition containing a compound capable of exhibiting a liquid crystal phase is applied thereon, and further suitable for orientation. Conditioning is generally done. Examples of the method for imparting the alignment regulating force to the surface of the base material include methods by photo-alignment (for example, Patent Documents 2 to 4) and rubbing (for example, Patent Documents 5 to 7). Further, there is also known a method of orienting a liquid crystal compound on a film by using a stretched film as a substrate (for example, Patent Documents 8 to 10).

JP, 10-68816, A Japanese Patent Publication No. 2008-542837 Japanese Patent No. 2980558 JP, 11-153712, A JP-A-8-160430 JP, 2000-267105, A JP 2002-6322A JP-A-3-9325 JP-A-4-16919 JP, 2003-207641, A

The method for producing an optical laminate having a plurality of optically anisotropic layers by the above-mentioned conventional technique is a method of forming each optically anisotropic layer on a plurality of substrates and bonding them. And a method of sequentially forming an optically anisotropic layer on a single-layer substrate. The former has a problem that the process is complicated. On the other hand, the latter is capable of imparting good quality to the first optically anisotropic layer formed directly on the substrate, but when forming the second or more optically anisotropic layers, stripes are formed on the surface. There is a problem that troubles such as entering are likely to occur.

Therefore, an object of the present invention is to provide a method for producing an optical layered body, which can easily and efficiently produce an optical layered body having a plurality of high-quality optically anisotropic layers, and a high-quality, simple and An object of the present invention is to provide an optical laminate, an optically anisotropic laminate, a circularly polarizing plate, and an organic electroluminescence display device that can be efficiently manufactured.

As a result of studies to solve the above-mentioned problems, the present inventor has found that in a method of sequentially forming an optically anisotropic layer on a specific substrate, a photo-alignment layer is formed when the second optically anisotropic layer is formed. It was found that the above-mentioned problems can be solved by imparting an orientation regulating force by the above and further by making the conditions of the operation for forming each layer specific, and completed the present invention.
That is, according to the present invention, the following is provided.

[1] A method for producing an optical layered body, comprising:
A step (I) of directly applying a first liquid crystal composition containing a first liquid crystal compound onto a long substrate to obtain a layer of the first liquid crystal composition,
The first liquid crystal composition is prepared by aligning the first liquid crystal compound in the layer of the first liquid crystal composition, and irradiating the layer of the first liquid crystal composition with an active energy ray under an inert gas atmosphere. Curing (II) to form a first optically anisotropic layer (II),
A liquid containing a photo-alignment material is directly applied onto the first optically anisotropic layer to obtain a layer of a liquid containing the photo-alignment material, which is different from the width direction of the substrate in an inert gas atmosphere. Irradiation of polarized light having a polarization direction to the layer of the liquid containing the photo-alignment material to form a photo-alignment layer (III), and a second liquid crystal compound directly on the photo-alignment layer. The second liquid crystal composition is applied to obtain a layer of the second liquid crystal composition, and the second liquid crystal compound in the layer of the second liquid crystal composition is aligned to form the second liquid crystal. Step (IV) of irradiating the composition layer with active energy rays to cure the second liquid crystal composition to form a second optically anisotropic layer.
And a manufacturing method.
[2] The method for producing an optical laminate according to [1],
The manufacturing method, wherein the irradiation polarization direction in the step (III) forms an angle with the width direction of 10 to 20° or 70 to 80°.
[3] The method for producing an optical laminate according to [1] or [2],
The manufacturing method, wherein the integrated light amount of irradiation in the step (II) and the step (III) is 1000 mJ/cm ² or more.
[4] An optical layered body manufactured by the manufacturing method according to any one of [1] to [3],
The base material has an alignment regulating force, and the alignment axis direction is in a direction different from the width direction,
The slow axis of the first optically anisotropic layer is parallel to the alignment axis direction of the substrate, and
An optical laminate, wherein an angle formed by the slow axis of the first optically anisotropic layer and the slow axis of the second optically anisotropic layer is 55° to 65°.
[5] The optical laminate according to [4],
The surface of the first optical anisotropic layer on the side of the photo-alignment layer has a pencil hardness of B or more, and
An optical laminate in which the pencil hardness of the surface of the photo-alignment layer on the side of the second optical anisotropic layer is B or more.
[6] The optical layered body according to [4] or [5],
An optical laminate in which the substrate is a stretched film.
[7] The optical layered body according to any one of [4] to [6],
An optical laminate, wherein the base material is a film of a resin containing an alicyclic structure-containing polymer.
[8] The optical laminate according to any one of [4] to [7],
An optical laminate, wherein one of the first optically anisotropic layer and the second optically anisotropic layer is a λ/4 wavelength plate, and the other is a λ/2 wavelength plate.
[9] An optically anisotropic laminate including a first optically anisotropic layer, a photo-alignment film, and a second optically anisotropic layer in this order,
An optically anisotropic laminate obtained by peeling the base material from the optical laminate according to any one of [4] to [8].
[10] A circularly polarizing plate obtained by laminating the optically anisotropic laminate according to [9] and a long linear polarizer by roll-to-roll,
The optically anisotropic layer on the side of the optically anisotropic laminate that is bonded to the linear polarizer is a λ/2 wavelength plate,
A circularly polarizing plate in which an angle formed by the transmission axis of the linear polarizer and the slow axis of the optically anisotropic layer on the side to be bonded to the linear polarizer is 10 to 20° or 70 to 80°.
[11] An organic electroluminescence display device including the circularly polarizing plate according to [10].

According to the method for producing an optical laminate of the present invention, it is possible to easily and efficiently produce an optical laminate having a plurality of high-quality optically anisotropic layers. Further, the optical layered body, the optically anisotropic layered body, the circularly polarizing plate and the organic electroluminescence display device of the present invention can be manufactured with high quality simply and efficiently.

FIG. 1 is a sectional view schematically showing an example of an optical layered body obtained by the manufacturing method of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of the optically anisotropic laminate obtained from the optical laminate shown in FIG. FIG. 3 is a cross-sectional view schematically showing an example of a circularly polarizing plate obtained from the optically anisotropic laminate shown in FIG. FIG. 4 is a cross-sectional view schematically showing another example of the optical layered body obtained by the manufacturing method of the present invention. FIG. 5 is a cross-sectional view schematically showing an example of the optically anisotropic laminate obtained from the optical laminate shown in FIG. FIG. 6 is a cross-sectional view schematically showing an example of a circularly polarizing plate obtained from the optically anisotropic laminate shown in FIG.

Hereinafter, the present invention will be described in detail with reference to examples and embodiments, but the present invention is not limited to the following examples and embodiments, and the scope of claims of the present invention and the equivalent range thereof. It may be arbitrarily modified and implemented within a range that does not deviate.
In the present application, the member having a plate shape such as a “polarizing plate”, a “λ/2 wavelength plate”, a “λ/4 wavelength plate” and a “retardation plate” is not limited to a rigid member, but a film. The shape may be flexible.
In the present application, the angular relationship of the constituent elements being “parallel” or “vertical” may include an error within a range that does not impair the effects of the present invention, unless otherwise specified. For example, it may include an error within 5°, preferably within 3°, and more preferably within 1°.
Further, in particular, in the present application, “approximately 15°” is 15° or an angle close thereto, preferably 10 to 20°, more preferably 11 to 19°, still more preferably 12 to 18°. On the other hand, “approximately 75°” is 75° or an angle close thereto, preferably 70 to 80°, more preferably 71 to 79°, and even more preferably 72 to 78°.

[1. Outline of manufacturing method of optical laminate]
The manufacturing method of the optical layered body of the present invention,
A step (I) of directly applying a first liquid crystal composition containing a first liquid crystal compound onto a long substrate to obtain a layer of the first liquid crystal composition,
Aligning the first liquid crystal compound in the layer of the first liquid crystal composition, and irradiating the layer of the first liquid crystal composition with an active energy ray in an inert gas atmosphere to cure the first liquid crystal composition; A step (II) of forming a first optically anisotropic layer,
The liquid containing the photo-alignment material is directly applied onto the first optically anisotropic layer to obtain a layer of the liquid containing the photo-alignment material, and the layer in a direction different from the width direction of the substrate is provided in an inert gas atmosphere. A step (III) of forming a photo-alignment layer by irradiating a layer of a liquid containing a photo-alignment material with polarized ultraviolet light having an irradiation polarization direction, and a second step of directly containing the second liquid crystal compound on the photo-alignment layer. Is applied to obtain a layer of the second liquid crystal composition, the second liquid crystal compound in the layer of the second liquid crystal composition is aligned, and active energy is applied to the layer of the second liquid crystal composition. Step (IV) of irradiating a ray to cure the second liquid crystal composition to form a second optically anisotropic layer.
including.

[2. Step (I): Substrate]
The base material used in the present invention is a long base material. In the present application, the “long shape” means a shape having a length of at least 5 times or more the width, preferably having a length of 10 times or more, specifically a roll shape. The shape of a film that has a length such that it can be wound up and stored or transported.

The material of the base material is not particularly limited, and various resins can be used. Examples of the resin include resins containing various polymers. Examples of the polymer include alicyclic structure-containing polymer, cellulose ester, polyvinyl alcohol, polyimide, UV transparent acrylic, polycarbonate, polysulfone, polyether sulfone, epoxy polymer, polystyrene, and combinations thereof. Among these, the alicyclic structure-containing polymer and the cellulose ester are preferable, and the alicyclic structure-containing polymer is more preferable, from the viewpoints of transparency, low hygroscopicity, dimensional stability, lightness, and the like.

The substrate is preferably a resin film having a positive intrinsic birefringence. When a resin having a positive intrinsic birefringence is used as a material, it is possible to easily obtain a base material having good properties such as high alignment regulation force, high strength, and low cost. ..

The alicyclic structure-containing polymer is an amorphous polymer having an alicyclic structure in the repeating unit, and a polymer having an alicyclic structure in the main chain and an alicyclic structure in the side chain. Any of the polymers contained can be used.
Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure, and the cycloalkane structure is preferable from the viewpoint of thermal stability and the like.
The number of carbon atoms constituting one repeating unit of the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20, and more preferably 6 to 15.

The proportion of repeating units having an alicyclic structure in the alicyclic structure-containing polymer is appropriately selected according to the purpose of use, but is usually 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight. That is all.
When the repeating unit having an alicyclic structure is excessively small, the heat resistance of the film may be reduced.

Specific examples of the alicyclic structure-containing polymer include (1) norbornene polymer, (2) monocyclic cycloolefin polymer, (3) cyclic conjugated diene polymer, (4) vinyl alicyclic hydrocarbon. Examples thereof include polymers and hydrogenated products thereof.
Among these, norbornene polymers and hydrogenated products thereof are more preferable from the viewpoint of transparency and moldability.

Examples of the norbornene polymer include ring-opening polymers of norbornene monomers, ring-opening copolymers of norbornene monomers with other monomers capable of ring-opening copolymerization, and hydrogenated products thereof; addition polymers of norbornene monomers, Examples thereof include addition copolymers of norbornene monomers and other copolymerizable monomers.
Among these, the hydrogenated product of a ring-opening polymer of a norbornene monomer is most preferable from the viewpoint of transparency.
The alicyclic structure-containing polymer is selected from the known polymers disclosed in, for example, JP-A-2002-321302.

The glass transition temperature of the alicyclic structure-containing polymer is preferably 80° C. or higher, more preferably 100 to 250° C.
The alicyclic structure-containing polymer having a glass transition temperature in such a range has excellent durability without causing deformation or stress during use at high temperature.

The molecular weight of the alicyclic structure-containing polymer is the polyisoprene conversion measured by gel permeation chromatography (hereinafter, abbreviated as "GPC") using cyclohexane (toluene when the resin does not dissolve) as a solvent. The weight average molecular weight (Mw) in terms of polystyrene (when the solvent is toluene) is usually 10,000 to 100,000, preferably 25,000 to 80,000, and more preferably 25,000 to 50,000. is there.
When the weight average molecular weight is in such a range, the mechanical strength and the moldability of the film are highly balanced, which is preferable.

The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) of the alicyclic structure-containing polymer is not particularly limited, but is usually 1 to 10, preferably 1 to 4, and more preferably 1.2 to 3 The range is 0.5.

The resin containing the alicyclic structure-containing polymer has a content of a resin component (that is, an oligomer component) having a molecular weight of 2,000 or less, preferably 5% by weight or less, more preferably 3% by weight or less, and further preferably It is 2% by weight or less.
When the amount of the oligomer component is within the above range, the generation of fine projections on the surface is reduced, the thickness unevenness is reduced, and the surface accuracy is improved.
In order to reduce the amount of the oligomer component, the selection of the polymerization catalyst or hydrogenation catalyst, the reaction conditions such as polymerization and hydrogenation, the temperature condition in the step of pelletizing the resin as a molding material, etc. may be optimized. ..
The component amount of the oligomer can be measured by the above-mentioned GPC.

The thickness of the base material is not particularly limited, but the thickness is usually 1 to 1000 μm, preferably 5 to 300 μm, and more preferably 30 to 100 μm from the viewpoint of facilitating productivity improvement, thinning, and weight reduction. ..

The resin containing the alicyclic structure-containing polymer may be composed of only the alicyclic structure-containing polymer, but may contain any compounding agent as long as the effects of the present invention are not significantly impaired. The proportion of the alicyclic structure-containing polymer in the resin containing the alicyclic structure-containing polymer is preferably 70% by weight or more, more preferably 80% by weight or more.
Preferable specific examples of the resin containing the alicyclic structure-containing polymer include “Zeonor 1420 and Zeonor 1420R” manufactured by Nippon Zeon Co., Ltd.

As the cellulose ester, a lower fatty acid ester of cellulose (eg, cellulose acetate, cellulose acetate butyrate and cellulose acetate propionate) is representative. The lower fatty acid means a fatty acid having 6 or less carbon atoms per molecule. Cellulose acetate includes triacetyl cellulose (TAC) and cellulose diacetate (DAC).

The acetylation degree of cellulose acetate is preferably 50 to 70%, and particularly preferably 55 to 65%. The weight average molecular weight is preferably 70,000 to 120,000, particularly preferably 80,000 to 100,000. The cellulose acetate may be partially esterified with a fatty acid such as propionic acid and butyric acid as long as it satisfies the acetic acid degree as well as acetic acid. Further, the resin constituting the base material may include a combination of cellulose acetate and a cellulose ester other than cellulose acetate (eg, cellulose propionate and cellulose butyrate). In that case, it is preferable that all of these cellulose esters satisfy the above acetylation degree.

When a film of triacetyl cellulose is used as a substrate, such a film may be a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent substantially free of dichloromethane by a low temperature dissolution method or a high temperature dissolution method. A triacetyl cellulose film produced by using is particularly preferable from the viewpoint of environmental protection. A film of triacetyl cellulose can be produced by a co-casting method. In the co-casting method, raw material flakes of triacetyl cellulose are dissolved in a solvent, and if necessary, any additive is added to prepare a solution (dope), and the dope is supported from a dope supply means (die). It can be carried out by casting on a body, peeling the cast product as a film from the support at a time when the cast product is dried to some extent to give rigidity, and further drying the film to remove the solvent. Examples of the solvent for dissolving the raw material flakes include halogenated hydrocarbons (dichloromethane etc.), alcohols (methanol, ethanol, butanol etc.), esters (methyl formate, methyl acetate etc.), ethers (dioxane, dioxolane, etc.). Diethyl ether, etc.) and the like. Examples of the additive added to the dope include a retardation increasing agent, a plasticizer, an ultraviolet absorber, a deterioration preventing agent, a slip agent, and a peeling accelerator. Examples of the support on which the dope is cast include a horizontal endless metal belt and a rotating drum. Upon casting, a single dope can be cast as a single layer, or a plurality of layers can be cast as a co-cast. When co-casting a plurality of layers, for example, a low-concentration cellulose ester dope layer and a high-concentration cellulose ester dope layer provided in contact with the front surface and the back surface thereof to form a plurality of layers. Can be sequentially cast. Examples of means for drying the film to remove the solvent include means for transporting the film and passing it through a drying section in which conditions suitable for drying are passed.

Preferable examples of the triacetyl cellulose film include known ones such as TAC-TD80U (manufactured by Fuji Photo Film Co., Ltd.) and those disclosed in JIII Journal of Technical Disclosure No. 2001-1745. To be The thickness of the triacetyl cellulose film is not particularly limited, but is preferably 30 to 150 μm, more preferably 40 to 130 μm, and further preferably 70 to 120 μm.

It is preferable that the base material has excellent transparency in order to increase the degree of freedom in the manufacturing process. Specifically, the total light transmittance of the base material is preferably 80% or more, more preferably 85% or more, and particularly preferably 88% or more. The total light transmittance of the substrate can be measured using a UV-visible spectrometer in the wavelength range of 400 nm to 700 nm.

The long base material is preferably prepared in the shape of a roll and can be fed to the production method of the present invention by feeding it out at the time of use.

In a preferred embodiment, the base material has an orientation regulating force. The alignment control force is the ability to control the alignment of the liquid crystal compound in the layer of the liquid crystal composition formed thereon. The orientation regulating force may be applied to the base material by stretching the base material before stretching to obtain a stretched base material. In the stretched base material, the molecules constituting the base material are oriented, and an orientation regulating force can be expressed in the orientation axis direction. By thus imparting the orientation regulating force by stretching, it is possible to easily manufacture a substrate capable of achieving orientation of a high-quality optically anisotropic layer.

In a preferred embodiment, the orientation axis direction of the substrate is different from the width direction of the substrate. The angle formed by the orientation axis of the base material and the width direction of the base material may be specifically more than 0° and less than 90°. By having the orientation axis at an angle in such a range, the optical layered body of the present invention can be used as a material that enables efficient production of a circularly polarizing plate or the like.
More specifically, the angle formed by the orientation axis of the base material and the width direction of the base material is set to a specific range such as about 75° or about 15°, so that it can be effectively used as a material for a broadband antireflection film. The optical layered product which can be obtained can be manufactured efficiently.

The stretching of the base material before stretching may be only diagonal stretching, transverse stretching (stretching in the width direction of the substrate), longitudinal stretching (stretching in the longitudinal direction of the substrate), or these. The stretching may be combined. The stretching ratio can be appropriately set within the range where the alignment regulating force is generated on the surface of the base material. When a resin whose base material has a positive intrinsic birefringence is used as a material, molecules are oriented in the stretching direction and an orientation axis is developed in the stretching direction. Stretching can be performed using a known stretching machine such as a tenter stretching machine.

The retardation Re in the in-plane direction of the substrate is preferably 10 nm or more, more preferably 50 nm or more, while preferably 500 nm or less, more preferably 300 nm or less. The lower limit of the birefringence Δn of the substrate is preferably 0.000050 or more, more preferably 0.000070 or more, while the upper limit of the birefringence Δn of the substrate is preferably 0.007500 or less, more preferably 0. It is 007000 or less. In particular, by using a resin containing the alicyclic structure-containing polymer described above or a resin containing triacetyl cellulose as the material of the base material, and by imparting optical properties within the range, the entire thickness direction of the base material can be improved. The molecular director can be oriented substantially uniformly over the entire length, and a good orientation control force can be applied to the surface of the substrate.

[3. Process (I)]
In step (I) of the method for producing an optical layered body of the present invention, the first liquid crystal composition is directly applied onto the substrate to obtain a layer of the first liquid crystal composition.

“Direct” application of the liquid crystal composition onto the substrate means application of the liquid crystal composition onto the surface of the substrate without interposing other layers. When a substrate having an alignment controlling force is adopted and the surface of the substrate is directly coated with the liquid crystal composition, an optically anisotropic layer having a slow axis in a desired direction can be obtained.
When the liquid crystal composition is applied onto a substrate, the substrate should be applied with an appropriate tension (usually 100 to 500 N/m) to reduce the conveyance flutter of the substrate and maintain the flatness. Is preferred. The flatness is a shake amount in the vertical direction perpendicular to the width direction and the conveyance direction of the base material, and is ideally 0 mm, but is usually 1 mm or less.
The surface roughness (Ra) of the surface of the substrate on which the liquid crystal composition is applied is preferably 0.05 μm or less, more preferably 0.005 μm or less. When it is at most the upper limit, it is possible to obtain an optically anisotropic layer having less uneven coating and excellent flatness. The surface roughness (Ra) can be measured according to JIS B0601.

The supply of the base material to the step (I) can be performed by preparing the roll of the specific long base material described above and feeding the base material from the roll.

Examples of specific operations for applying the first liquid crystal composition include curtain coating method, extrusion coating method, roll coating method, spin coating method, dip coating method, bar coating method, spray coating method, slide coating method, The printing coating method, the gravure coating method, the die coating method, the cap coating method, and the dipping method are mentioned.

The thickness of the layer of the first liquid crystal composition is not particularly limited, and can be appropriately adjusted so that the thickness of the first optically anisotropic layer has a desired value. Conditions such as the temperature at the time of coating can be appropriately set to a temperature at which the coating and the subsequent steps can be smoothly performed.

[3.1. First liquid crystal composition]
The first liquid crystal composition is a composition containing the first liquid crystal compound.

In the present application, the first liquid crystal compound as a component of the first liquid crystal composition is a compound that can exhibit a liquid crystal phase when blended with the first liquid crystal composition and aligned. The polymerizable liquid crystal compound is a liquid crystal compound which is polymerized in the first liquid crystal composition in a state of exhibiting such a liquid crystal phase and can be a polymer while maintaining the alignment of molecules in the liquid crystal phase.
In addition, in the present application, the polymerizable compounds (polymerizable liquid crystal compounds and other polymerizable compounds, etc.) that are components of the first liquid crystal composition are collectively referred to simply as “polymerizable compounds”. is there.

[3.1.1. Polymerizable liquid crystal compound]
Examples of the polymerizable liquid crystal compound include a liquid crystal compound having a polymerizable group, a compound capable of forming a side chain type liquid crystal polymer, and a discotic liquid crystal compound. Examples of the liquid crystal compound having a polymerizable group include JP-A Nos. 11-513360, 2002-030042, 2004-204190, 2005-263789, and 2007-119415. Examples thereof include rod-like liquid crystal compounds having a polymerizable group described in JP-A-2007-186430, and reverse wavelength dispersion liquid crystal compounds described in International Publication No. WO2012/147904. Examples of the side chain type liquid crystal polymer compound include the side chain type liquid crystal polymer compound described in JP 2003-177242 A and the like. In addition, examples of preferable liquid crystal compounds by product name include “LC242” manufactured by BASF. Specific examples of the discotic liquid crystal compound include JP-A-8-50206, C. Destrade et al., Mol. Crysr. Liq. Cryst., vol. 71, page 111 (1981); Chemical Society of Japan. Ed., Quarterly Chemistry Review, No. 22, Chemistry of Liquid Crystals, Chapter 5, Chapter 10, Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., page 1794 (1985). ); J. Zhang et al., J. Am. Chem. Soc., vol. 116, page 2655 (1994)). As the polymerizable liquid crystal compound, one of these liquid crystal compounds and other liquid crystal compounds described below may be used alone, or two or more thereof may be used in combination at an arbitrary ratio.

Further examples of the polymerizable liquid crystal compound include rod-like liquid crystal compounds represented by the following general formula (1).
^{R 1 -C 1 -D 1 -C 3} -M-C 4 -D 2 -C 2 -R 2 (1)

In the general formula (1), R ¹ and R ² each independently represent a polymerizable functional group. Examples of the polymerizable functional group include a carboxyl group, a (meth)acrylic group, an epoxy group, a thioepoxy group, a mercapto group, an isocyanate group, an isothiocyanate group, an oxetane group, a thietanyl group, an aziridinyl group, a pyrrole group, a vinyl group, and an allyl group. Group, fumarate group, cinnamoyl group, oxazoline group, hydroxyl group, alkoxysilyl group, amino group and the like. (Meth)acrylic refers to acrylic and methacrylic.

In the general formula (1), D ¹ and D ² are each independently a single bond, a linear or branched methylene group having 1 to 20 carbon atoms, and a divalent saturated carbon atom such as an alkylene group. It represents a hydrogen group and a group selected from the group consisting of a linear or branched alkylene oxide group having 1 to 20 carbon atoms.

In the general formula (1), C ^{1 to} C ⁴ are each independently a single bond, —O—, —S—, —S—S—, —CO—, —CS—, —OCO—, —CH. _{2 -, - OCH 2 -,} - CH = N-N = CH -, - NHCO -, - OCOO -, - CH 2 COO-, and represents a group selected from the group consisting of _-CH 2 OCO-.

In the general formula (1), M represents a mesogen group. Specific examples of M include azomethines, azoxys, phenyls, biphenyls, terphenyls, naphthalenes, anthracenes, benzoates, and cyclohexanecarboxylic which may be unsubstituted or have a substituent. 2 to 4 skeletons selected from the group consisting of acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolans, alkenylcyclohexylbenzonitriles, -O -, - S -, - S -S -, - CO -, - CS -, - OCO -, - CH 2 -, - OCH 2 -, - CH = N-N = CH -, - NHCO -, - OCOO _-, - CH 2 _COO-, and a group formed by being linked by linking groups _-CH 2 OCO- or the like.

Examples of the substituent that the mesogen group M may have include a halogen atom, an alkyl group having 1 to 10 carbon atoms which may have a substituent, a cyano group, a nitro group, —O—R ³ , — ^{O-C (= O) -R} 3, -C (= O) -O-R 3, -O-C (= O) -O-R 3, -NR 3 -C (= O) -R 3, -C (= O) represents the ^-NR 3 ^{R 4} or ^{-O-C (= O) -NR} 3 R 4,.
Here, R ³ and R ⁴ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. When R ³ and R ⁴ are alkyl groups, the alkyl groups include —O—, —S—, —O—C(═O)—, —C(═O)—O—, —O—C. ^{(= O) -O -, -} NR 5 -C (= O) -, - C (= O) -NR 5 -, - NR 5 -, or -C (= O) - may be interposed (However, the case where two or more -O- and -S- are adjacently interposed is excluded.). Here, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the substituent in the above-mentioned "alkyl group having 1 to 10 carbon atoms which may have a substituent" include a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amino group, and a carbon atom having 1 to 6 carbon atoms. Alkoxy group, alkoxyalkoxy group having 2 to 8 carbon atoms, alkoxyalkoxyalkoxy group having 3 to 15 carbon atoms, alkoxycarbonyl group having 2 to 7 carbon atoms, alkylcarbonyl having 2 to 7 carbon atoms Examples thereof include an oxy group and an alkoxycarbonyloxy group having 2 to 7 carbon atoms.

[3.1.2. Other Components of First Liquid Crystal Composition]
The first liquid crystal composition may contain, in addition to the polymerizable liquid crystal compound, any component such as those exemplified below, if necessary.

The first liquid crystal composition may include a polymerization initiator. The polymerization initiator may be appropriately selected depending on the type of the polymerizable liquid crystal compound in the first liquid crystal composition and the polymerizable group contained in the other polymerizable compound. For example, if the polymerizable group is radically polymerizable, a radical polymerization initiator may be used, if it is an anionic polymerizable group, an anionic polymerization initiator may be used, and if it is a cationically polymerizable group, a cationic polymerization initiator may be used. ..

As the radical polymerization initiator, a heat radical generator that is a compound that generates an active species capable of initiating the polymerization of a polymerizable compound when heated; and visible light, ultraviolet light (i-ray, etc.), far ultraviolet light, electron beam , A photoradical generator that is a compound that generates an active species capable of initiating the polymerization of a polymerizable compound when exposed to exposure light such as X-rays; however, a photoradical generator is used. Is preferred.

Examples of the photoradical generator include acetophenone compounds, biimidazole compounds, triazine compounds, O-acyloxime compounds, onium salt compounds, benzoin compounds described in International Publication No. WO2012/147904. Examples thereof include a benzophenone compound, an α-diketone compound, a polynuclear quinone compound, a xanthone compound, a diazo compound, and an imidosulfonate compound.

Examples of the anionic polymerization initiator include alkyllithium compounds; monolithium salts or monosodium salts such as biphenyl, naphthalene, and pyrene; polyfunctional initiators such as dilithium salts and trilithium salts; and the like.

Examples of the cationic polymerization initiator include protonic acids such as sulfuric acid, phosphoric acid, perchloric acid and trifluoromethanesulfonic acid; Lewis acids such as boron trifluoride, aluminum chloride, titanium tetrachloride and tin tetrachloride. An aromatic onium salt or a combination system of an aromatic onium salt and a reducing agent;

A commercially available product may be used as the polymerization initiator. For example, trade names: Irgacure 907, trade names: Irgacure 184, trade names: Irgacure 369, product names: Irgacure 651, product names: Irgacure 819, product names: Irgacure 907, product names: Irgacure 379E, Ac, Og, and Iacure UR, Iacure O, and Irgacure Og. Trade name: ADEKA OPTOMER N1919 can be used.
These polymerization initiators may be used alone or in combination of two or more.
In the first liquid crystal composition, the mixing ratio of the polymerization initiator is usually 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the polymerizable compound.

The first liquid crystal composition may include a surfactant for adjusting the surface tension. The surfactant is not particularly limited, but usually a nonionic surfactant is preferable. Examples of the nonionic surfactant include nonionic surfactants which are oligomers having a molecular weight of about several thousand.
A commercially available product may be used as the surfactant. For example, as specific examples of these surfactants, "PF-151N", "PF-636", "PF-6320", "PF-656", "PF-6520", "PF-" of PolyFox of OMNOVA. 3320", "PF-651", "PF-652";"FTX-209F","FTX-208G","FTX-204D" of Neos Co., Ltd. Futgent; S-420" or the like can be used. Further, one kind of the surfactant may be used alone, or two or more kinds thereof may be used in combination at an arbitrary ratio.
In the first liquid crystal composition, the mixing ratio of the surfactant is usually 0.01 to 10 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the polymerizable compound.

The first liquid crystal composition may include a solvent such as an organic solvent. Examples of such organic solvents include ketones such as cyclopentanone, cyclohexanone, methyl ethyl ketone, acetone and methyl isobutyl ketone; acetic acid esters such as butyl acetate and amyl acetate; halogenated hydrocarbons such as chloroform, dichloromethane and dichloroethane; Ethers such as 1,4-dioxane, cyclopentyl methyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxolane and 1,2-dimethoxyethane; and aromatic hydrocarbons such as toluene, xylene and mesitylene. The boiling point of the solvent is preferably 60 to 250°C, and more preferably 60 to 150°C from the viewpoint of excellent handleability. The amount of the solvent used is usually 100 to 1000 parts by weight with respect to 100 parts by weight of the polymerizable compound.

The first liquid crystal composition further comprises a metal, a metal complex, a dye, a pigment, a fluorescent material, a phosphorescent material, a leveling agent, a thixotropic agent, a gelling agent, a polysaccharide, an ultraviolet absorber, an infrared absorber, an antioxidant, It may contain optional additives such as ion exchange resins and metal oxides such as titanium oxide. In the polymerizable composition of the present invention, the compounding ratio of such optional additives is usually 0.1 to 20 parts by weight per 100 parts by weight of the polymerizable compound.

The first liquid crystal composition can usually be prepared by mixing the components described above.

[4. Step (II)]
In the step (II) of the method for producing an optical layered body of the present invention, the first liquid crystal compound in the layer of the first liquid crystal composition is aligned, and the layer of the first liquid crystal composition is subjected to an inert gas atmosphere. The first liquid crystal composition is cured by irradiation with active energy rays to form a first optically anisotropic layer.

The alignment of the first liquid crystal compound may be achieved immediately by coating, or may be achieved by performing an alignment treatment such as heating after coating, if necessary. The conditions for the alignment treatment may be appropriately set depending on the properties of the liquid crystal composition used, and for example, the conditions may be such that the treatment is performed at a temperature of 50 to 160° C. for 30 seconds to 5 minutes. By appropriately setting the composition of the liquid crystal composition to be used and the treatment conditions, it is possible to achieve the alignment along the same direction as the alignment axis of the substrate.

Irradiation with active energy rays may be carried out immediately after orientation, but a step of drying the layer of the liquid crystal composition may be carried out immediately after irradiation with active energy rays immediately after orientation. Such drying can be achieved by a drying method such as natural drying, heat drying, reduced pressure drying, and reduced pressure heat drying. By such drying, the solvent can be removed from the layer of the liquid crystal composition.

Irradiation with active energy rays is performed in an inert gas atmosphere. Examples of the inert gas include nitrogen and argon, and nitrogen is preferable because of its low cost. The oxygen concentration in the inert gas atmosphere is preferably 3% or less, more preferably 1% or less, and particularly preferably 500 ppm or less.

As the other conditions for irradiation with active energy rays, conditions suitable for the properties of the components of the liquid crystal composition can be appropriately selected. The active energy rays to be irradiated may include light such as visible rays, ultraviolet rays, and infrared rays, and arbitrary energy rays such as electron rays. Among them, the method of irradiating light such as ultraviolet rays is preferable because the operation is simple. It is preferable that the upper limit of the temperature at the time of ultraviolet irradiation is set to the glass transition temperature (Tg) of the substrate or lower. It is usually 150° C. or lower, preferably 100° C. or lower, and particularly preferably 80° C. or lower. The lower limit of the temperature during UV irradiation may be 15°C or higher. Ultraviolet irradiation intensity is ^{usually, 0.1mW / cm 2 ~1000mW / cm} 2 range, preferably in the range of ^{0.5mW / cm 2 ~600mW / cm 2} . The ultraviolet irradiation time is in the range of 1 second to 300 seconds, preferably 5 seconds to 100 seconds. It is determined by the integrated amount of ultraviolet rays (mJ/cm ² )=UV irradiation intensity (mW/cm ² )×irradiation time (seconds). The integrated light amount is preferably in the range of 10 to 5000 mJ/cm ² . As the ultraviolet irradiation light source, a high pressure mercury lamp, a metal halide lamp, or a low pressure mercury lamp can be used.

Irradiation with active energy rays can be performed on the coated surface side (the side of the laminate of the substrate/first liquid crystal composition layer on which the first liquid crystal composition layer is formed), If the transparency of the material is sufficiently high, it can be performed from the back surface side (the side opposite to the side on which the liquid crystal composition layer is formed).

The pencil hardness of the surface of the first optically anisotropic layer obtained as a result of the step (II) is preferably B or more, and preferably 4H or less. If the pencil hardness is less than B, the scratch resistance may be insufficient, and scratches may easily occur in the carrying step. If the pencil hardness exceeds 4H, the optically anisotropic layer may become too brittle and the crack generation rate may increase. The first optically anisotropic layer having such a high surface hardness can be easily obtained by performing active energy ray irradiation under the above-described conditions such as the inert gas atmosphere. The pencil hardness can be measured based on JIS K5600-5-4.

[5. Step (III)]
In step (III) of the method for producing an optical layered body of the present invention, a liquid containing a photo-alignment material (hereinafter, may be referred to as “photo-alignment material liquid”) directly on the first optically anisotropic layer. After coating to obtain a layer of the photo-alignment material liquid, the layer of the photo-alignment material is irradiated with polarized ultraviolet light having an irradiation polarization direction different from the width direction of the base material in an inert gas atmosphere to form the photo-alignment layer. Form.
When the photo-alignment material is applied on the first optically anisotropic layer formed on the base material, the base material is tensioned with an appropriate tension (usually 100 to 500 N/m), and the base material is fluttered. It is preferable that the amount is reduced to maintain the flatness. The flatness is a shake amount in the vertical direction perpendicular to the width direction and the conveyance direction of the base material, and is ideally 0 mm, but is usually 1 mm or less.

By thus forming the photo-alignment layer directly on the first optically anisotropic layer, a thin optical laminate can be easily formed. Further, in the production method of the present invention, the first optically anisotropic layer having a high surface hardness can be obtained by forming the first optically anisotropic layer by the above-described specific method. Even if the photo-alignment layer is directly formed, there is little tendency to form streaky scratches on the surface.

The photo-alignment material is a material that is irreversibly aligned by being irradiated with polarized light. As an example of such a photo-alignment material, a PPN material used for a PPN layer described in Japanese Patent No. 4267080, which is a photo-reactive type in which molecules themselves are changed by irradiating polarized light, and Japanese Patent No. 4647782 are described. The LPP/LCP mixture described, the PPN material described in Japanese Patent No. 2543666, and the photo-isomerization type that changes the molecular shape by cis-trans photo-isomerization by irradiating polarized light, Japanese Patent No. 4816003, Examples include azobenzene-based materials described in Japanese Patent No. 4935982, Japanese Patent No. 5057157, and Japanese Patent No. 5076810. These may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary ratios. By forming a layer using such a material, a photo-alignment layer, that is, a layer having an alignment regulating force and capable of controlling the alignment regulating direction by irradiation of polarized light can be obtained.

The proportion of the photo-alignment material in the photo-alignment material liquid may be 0.5 to 30% by weight. If the proportion of the photo-alignment material is higher than the above range, it may be difficult to form an alignment layer having excellent planar roughness depending on the coating method of coating the photo-alignment layer on the first optically anisotropic layer. In some cases, if it is less than the above range, the drying load of the solvent increases, so that the coating speed may not be within the desired range. Other components of the photo-alignment material liquid are not particularly limited and may include any component such as a solvent. The type of solvent is not particularly limited as long as it can dissolve the photo-alignment material and the like to a desired concentration and does not dissolve the first optically anisotropic layer, and a solvent that is compatible with the photo-alignment material is appropriately selected and used. sell. Specifically, alcohol solvents such as methanol and ethanol, diol solvents such as ethylene glycol, propylene glycol, and 1,3-butanediol, tetrahydrofuran, 2-methoxyethanol, 2-butoxyethanol, 2-(2- Ether-based solvents such as ethoxyethoxy)ethanol and 2-(2-butoxyethoxy)ethanol, amide-based solvents such as 2-pyrrolidone, N-methylpyrrolidone, dimethylformamide and dimethylacetamide, γ-butyrolactone, chlorobenzene and dimethylsulfoxide. Organic solvents can be used. These may be used alone or in combination of two or more.

The specific operation of applying the photo-alignment material liquid is not particularly limited, and examples thereof include the same operations as those given as examples for applying the first liquid crystal composition.

The thickness of the layer of the photo-alignment material liquid is not particularly limited, and can be appropriately adjusted so that the thickness of the photo-alignment layer has a desired value. Conditions such as the temperature at the time of coating can be appropriately set to a temperature at which the coating and the subsequent steps can be smoothly performed.

The polarized UV is usually linearly polarized UV. Irradiation of polarized ultraviolet rays is performed in an inert gas atmosphere. Examples of the inert gas include nitrogen and argon, and nitrogen is preferable because of its low cost. The oxygen concentration in the inert gas atmosphere is preferably 3% or less, more preferably 1% or less, and particularly preferably 500 ppm or less.

Irradiation of polarized ultraviolet light can also be performed from the coating surface side of the layer of the photo-alignment material liquid (the side of the photo-alignment material liquid layer opposite to the first optically anisotropic layer side), or from the opposite side. However, irradiation from the coated surface side is preferable from the viewpoint of production efficiency and obtaining a high quality layer.

The “irradiation polarization direction” of polarized ultraviolet light is a direction in which the orientation of the photo-alignment material is regulated by the polarized ultraviolet light. Specific modes of irradiation of polarized ultraviolet light include front irradiation (that is, irradiation from a direction perpendicular to the irradiation surface) and oblique irradiation (that is, irradiation from a direction that is not perpendicular to the irradiation surface). A mode suitable for the photo-alignment material used can be appropriately adopted. The closer the front irradiation is to the vertical, the more efficiently the reaction of the photo-alignment material proceeds. When the front irradiation is performed, the photo-alignment material is oriented in a direction parallel or perpendicular to the polarization direction of the polarized ultraviolet light (direction of vibration plane of electric field) depending on the photo-alignment material used. If a photo-alignment material that is aligned in a direction parallel to the polarization direction of polarized ultraviolet light is selected, that direction becomes the "irradiation polarization direction", and the alignment regulating force can be imparted in the direction parallel to the polarization direction.

The irradiation polarization direction is set to a direction different from the width direction of the base material. The angle formed by the irradiation polarization direction and the width direction of the substrate may be specifically more than 0° and less than 90°. By setting the irradiation polarization direction to an angle within such a range, the optical layered body of the present invention can be used as a material that enables efficient production of a circularly polarizing plate or the like. More specifically, when the angle formed by the irradiation polarization direction and the width direction of the base material is set to a specific range such as approximately 15° or approximately 75°, it can be effectively used as a material for a broadband antireflection film. The laminated body can be efficiently manufactured.

As other conditions of the polarized ultraviolet irradiation, conditions suitable for the properties of the components of the liquid crystal composition can be appropriately selected. The upper limit of the temperature at the time of irradiation with polarized ultraviolet rays is preferably set to the glass transition temperature (Tg) of the substrate or lower. It is usually 150° C. or lower, preferably 100° C. or lower, and particularly preferably 80° C. or lower. The lower limit of the temperature during UV irradiation may be 15°C or higher. Ultraviolet irradiation intensity is ^{usually, 0.01mW / cm 2 ~200mW / cm} 2 range, preferably in the range of ^{0.1mW / cm 2 ~150mW / cm 2} . The ultraviolet irradiation time is in the range of 0.1 second to 60 seconds, preferably 1 second to 30 seconds. The integrated light amount is preferably in the range of 50 to 10000 mJ/cm ² , more preferably 100 to 5000 mJ/cm ² .
The maximum output wavelength of polarized ultraviolet light is preferably in the range of 300 nm to 500 nm. Further, it is preferable that, of the emitted light amount, the light amount derived from the light having a wavelength of 300 nm to 500 nm is 50% or more. By using polarized ultraviolet light having a wavelength in this range, the reaction of the photo-alignment material proceeds efficiently.

In the production method of the present invention, the total integrated light amount of the irradiation amount of the active energy ray irradiated in the step (II) and the polarized ultraviolet light irradiation amount irradiated in the step (III) is preferably 1000 mJ/cm ² or more, It is preferably 2000 mJ/cm ² or more. The upper limit of the total integrated light amount is not particularly limited, but may be 10,000 mJ/cm ² or less, for example. By performing irradiation with such a high integrated light amount, it is possible to further reduce the formation of streak-like scratches on the surface of the second optically anisotropic layer when it is directly formed thereon.

The thickness of the photo-alignment layer obtained as a result of the step (III) can be appropriately adjusted to a thickness at which the alignment regulating force for regulating the alignment of the second optically anisotropic layer can be obtained. Specifically, it is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 5 μm or less, more preferably 2 μm or less.

The pencil hardness of the surface of the photo-alignment layer obtained as a result of the step (III) is preferably B or higher, and preferably 4H or lower. When the pencil hardness is less than B, the scratch resistance may be insufficient and scratches may easily occur in the carrying step. If the pencil hardness exceeds 4H, the photo-alignment layer may become too brittle and the crack generation rate may increase. The photo-alignment layer having such a high surface hardness can be easily obtained by irradiating polarized ultraviolet rays satisfying the conditions such as the above-mentioned inert gas atmosphere. When the pencil hardness of the surface of the first optically anisotropic layer and the pencil hardness of the surface of the photo-alignment layer are both B or more, when the second optically anisotropic layer is directly formed thereon, The formation of streak-like scratches on the surface can be further reduced.

[6. Step (IV)]
In step (IV) of the method for producing an optical layered body of the present invention, the second liquid crystal composition containing the second liquid crystal compound is directly applied onto the photo-alignment layer to form a layer of the second liquid crystal composition. Then, the second liquid crystal compound in the layer of the second liquid crystal composition is aligned, and the layer of the second liquid crystal composition is irradiated with an active energy ray to cure the second liquid crystal composition, An optically anisotropic layer is formed. The second liquid crystal composition may be the same composition as the first liquid crystal composition or a different composition. Examples thereof include the same as those described above as the example of the first liquid crystal composition.

Specific examples of aspects of application of the second liquid crystal compound, alignment, and irradiation with active energy rays include the same as those described above as examples of those relating to the first liquid crystal composition. Irradiation with the active energy ray in the step (IV) is a step of forming the second optically anisotropic layer on the already formed strong first optically anisotropic layer and photo-alignment layer, and therefore is not necessarily inactive. It is not necessary to perform it in a gas atmosphere, but a higher quality optically anisotropic layer can be formed by performing it in the same inert gas atmosphere as in step (II).

In the optical layered body obtained by the production method of the present invention, the surface hardness is high and the surface properties are good by forming the first optically anisotropic layer and the photo-alignment layer by the specific method described above. Since an excellent photo-alignment film can be obtained, even if a second optically anisotropic layer is further formed on it, there is little tendency to form streak-like scratches on the surface, and uneven coating (application of the second liquid crystal composition It is possible to obtain a second optically anisotropic layer having less unevenness of the surface of the optically anisotropic layer due to the unevenness of.

[7. Optical characteristics of optically anisotropic layer]
In a preferred embodiment, one of the first optically anisotropic layer and the second optically anisotropic layer is a λ/4 wavelength plate, and the other is a λ/2 wavelength plate. Specifically, when the in-plane retardation Re measured at a measurement wavelength of 590 nm is in the range of 108 nm to 168 nm, it can be used as a λ/4 wavelength plate. When the in-plane retardation Re measured at a measurement wavelength of 590 nm is in the range of 245 nm to 305 nm, it can be used as a λ/2 wave plate. More specifically, in the case of a λ/4 wavelength plate, the in-plane retardation Re measured at a measurement wavelength of 590 nm is preferably 128 nm to 148 nm, more preferably 133 nm to 143 nm. In the case of a λ/2 wavelength plate, the in-plane retardation Re measured at a measurement wavelength of 590 nm is preferably 265 nm to 285 nm, more preferably 270 nm to 280 nm. Here, the in-plane retardation Re is calculated according to the following formula.
Re=(nx−ny)×d (where nx is the in-plane slow axis direction refractive index of the optically anisotropic layer (maximum in-plane refractive index), and ny is the optical anisotropy. The refractive index of the layer in the direction perpendicular to the slow axis, and d is the thickness (nm) of the optically anisotropic layer.) First optically anisotropic layer and second optically anisotropic layer Is a combination of such a λ/4 wavelength plate and a λ/2 wavelength plate, it can be used to facilitate an optical element such as a λ/4 wavelength plate or a circularly polarizing plate having a λ/2 wavelength plate. Can be manufactured.

The slow axis direction of the first optically anisotropic layer may be parallel to the alignment axis of the base material. Also, the slow axis direction of the second optically anisotropic layer may be parallel to the irradiation polarization direction of the polarized ultraviolet light.
More specifically, the angle formed by the slow axis of the first optically anisotropic layer and the width direction of the substrate can be set to a specific range such as approximately 75° or approximately 15°. Further, the angle formed by the slow axis of the second optically anisotropic layer and the width direction of the base material may be in a specific range such as approximately 15° or approximately 75°. The angle formed by the slow axis of the first optically anisotropic layer and the slow axis of the second optically anisotropic layer is preferably 55° to 65°, more preferably 56° to 64°, and even more preferably It may preferably be 57° to 63°. By setting the slow axis in such a specific range, an optical laminate that can be effectively used as a material for a broadband antireflection film can be efficiently produced.

In the optically anisotropic layer, the liquid crystal compound becomes a solid while exhibiting a liquid crystal phase and can form a cured liquid crystal molecule.
The cured liquid crystal molecules of the first optically anisotropic layer may preferably have a homogeneous alignment regularity along a direction substantially the same as the alignment axis direction of the substrate. In addition, the cured liquid crystal molecules of the second optically anisotropic layer may preferably have a homogeneous alignment regularity along a direction substantially the same as the irradiation polarization direction of polarized ultraviolet light. Here, “having a homogeneous alignment regularity” means that the average direction of the lines obtained by projecting the long axis direction of the mesogens of the cured liquid crystal molecules on the film surface is a certain direction (for example, the base The direction of the surface director of the material film). Further, the homogeneous alignment regularity “along the certain direction” means that the alignment direction substantially coincides with the certain direction. For example, the predetermined direction is an orientation control direction of the base material or the like. Whether or not the cured liquid crystal molecules have a homogeneous alignment regularity and the alignment direction thereof are measured in a slow axis direction using a retarder represented by AxoScan (manufactured by Axometrics) and a slow phase direction. This can be confirmed by measuring the retardation distribution for each incident angle in the axial direction. When the cured liquid crystal molecule is formed by polymerizing a polymerizable liquid crystal compound having a rod-shaped molecular structure, usually, the major axis direction of the mesogen of the polymerizable liquid crystal compound is the major axis of the mesogen of the cured liquid crystal molecule. Direction.

By using a substrate having the above-described predetermined orientation axis as the base material, and further selecting the material of the optically anisotropic layer as appropriate, the optically anisotropic layer can be formed along the same direction as the slow axis direction. Further, orientation regularity such as homogeneous orientation regularity can be imparted, and as a result, an optically anisotropic layer having such orientation regularity can be obtained.

The thickness of the optically anisotropic layer is not particularly limited and can be appropriately adjusted so that characteristics such as retardation can be set in a desired range. Specifically, the lower limit of the thickness is preferably 0.5 μm or more, more preferably 1.0 μm or more, while the upper limit of the thickness is preferably 10 μm or less, more preferably 7 μm or less. The thickness is preferably 5 μm or less, and more preferably 5 μm or less. When the same composition is used as the first liquid crystal composition and the second liquid crystal composition, one of the λ/4 wavelength plates and the other of λ/ It can be a two-wave plate.
The length and width of the optically anisotropic layer can be a long film-like shape similar to that of the base material, and this is cut into a shape such as a rectangle suitable for a desired application, if necessary. can do.

[8. Optically anisotropic laminate]
The optically anisotropic laminate of the present invention is an optically anisotropic laminate comprising a first optically anisotropic layer, a photo-alignment film and a second optically anisotropic layer in this order, The base material is peeled off from the laminate. In the present application, the laminated body having such a structure obtained from the optical laminated body is referred to as an “optical anisotropic laminated body” in order to distinguish it from the optical laminated body.

The optically anisotropic laminate of the present invention may further include a protective film such as a masking film attached to the optically anisotropic layer to protect the optically anisotropic layer, if necessary. Known masking films (for example, FF1025 and FF1035 manufactured by Treteger Co.; “SAT116T”, “SAT2038T-JSL” and “SAT4538T-JSL” manufactured by San-A Kaken Co., Ltd.; “NBO” manufactured by Fujimori Kogyo Co., Ltd. “-0424”, “TFB-K001”, “TFB-K0421” and “TFB-K202”; “DT-2200-25” and “K-6040” manufactured by Hitachi Chemical Co., Ltd.; “6010#75” manufactured by Teraoka Seisakusho. , “6010#100”, “6011#75” and “6093#75”) can be used. From the optically anisotropic laminate having such a masking film, the optically anisotropic layer can be easily transferred to another member. Therefore, an optical element having an optically anisotropic layer can be easily manufactured.

[9. Circular polarizing plate]
The circularly polarizing plate of the present invention is obtained by laminating the optically anisotropic laminate of the present invention and a long linear polarizer by roll-to-roll. Roll-to-roll bonding is the process of feeding a film from a long film roll, transporting it, and performing the process of bonding with other films on the transportation line, and further obtaining the bonded product. Is used as a take-up roll. For example, when laminating a linear polarizer and an optically anisotropic laminate, the optically anisotropic laminate is unrolled from a long roll of the optically anisotropic laminate, and this is conveyed, on a conveying line. Roll-to-roll bonding can be performed by performing a step of bonding with a linear polarizer and using the obtained bonded product as a winding roll. In this case, the linear polarizer can also be fed from the roll and supplied to the bonding step. As the linear polarizer to be bonded to the optically anisotropic laminate, one having a multi-layer structure that is previously bonded to the polarizer protective film may be used, and this may be bonded.

When natural light is incident on the polarizer used in the present invention, only one polarized light is transmitted. The degree of polarization of the polarizer used in the present invention is not particularly limited, but is preferably 98% or more, more preferably 99% or more. The average thickness of the polarizer is preferably 5 to 80 μm.

As the linear polarizer, a known polarizer used in devices such as liquid crystal display devices and other optical devices can be used. Examples of the linear polarizer, after adsorbing iodine or dichroic dye on the polyvinyl alcohol film, those obtained by uniaxially stretching in a boric acid bath, and iodine or dichroic dye on the polyvinyl alcohol film Examples thereof include those obtained by adsorbing and stretching, and further modifying a part of polyvinyl alcohol units in the molecular chain into polyvinylene units. Other examples of linear polarizers include grid polarizers, multilayer polarizers, cholesteric liquid crystal polarizers, and other polarizers having the function of separating polarized light into reflected light and transmitted light. Of these, a polarizer containing polyvinyl alcohol is preferable. Further, as the linear polarizer, commercially available products (for example, manufactured by Sanritz Co., Ltd., trade names “HLC2-5618S”, “LLC2-9218S”, “HLC2-2518”), manufactured by Nitto Denko Corporation, trade names “TEG1465DU”, “SEG1423DU”. ,"SEG5425DU", etc.) can be used.

For the bonding of the optically anisotropic laminate and the linear polarizer, the optically anisotropic layer on the side of the optically anisotropic laminate to be bonded to the linear polarizer is a λ/2 wavelength plate, and The angle formed by the transmission axis of the linear polarizer and the slow axis of the optically anisotropic layer on the side where the linear polarizer is attached is 10 to 20° or 70 to 80°.

In a certain product (optical laminate, optically anisotropic laminate, circularly polarizing plate, display device, etc.) according to the present invention, the direction and geometry of the in-plane optical axis (slow axis, transmission axis, transmission axis, etc.) The angular relationship between the target directions (longitudinal direction and width direction of the film, etc.) is defined as a shift in one direction being positive and a shift in the other direction being negative. The positive and negative directions are the constituent elements in the product. Commonly prescribed in. For example, in a certain circularly polarizing plate, “the direction of the slow axis of the λ/2 wavelength plate with respect to the direction of the transmission axis of the linear polarizer is 15°, and the retardation of the quarter wavelength plate with respect to the direction of the transmission axis of the linear polarizer is 1/4. "The direction of the phase axis is 75°" means the following two cases:
When observing the circularly polarizing plate from one side thereof, the direction of the slow axis of the λ/2 wave plate is shifted by 15° clockwise from the direction of the transmission axis of the linear polarizer, and 1/4λ The direction of the slow axis of the wave plate is shifted by 75° clockwise from the direction of the transmission axis of the linear polarizer.
When observing the circularly polarizing plate from one surface thereof, the direction of the slow axis of the λ/2 wave plate is shifted by 15° counterclockwise from the direction of the transmission axis of the linear polarizer, and 1/ The direction of the slow axis of the 4λ wavelength plate is shifted by 75° counterclockwise from the direction of the transmission axis of the linear polarizer.

Preferable examples of the circularly polarizing plate of the present invention include the following examples (a) and (b).
Example (a): A linear polarizer, a λ/2 wave plate, and a λ/4 wave plate are provided in this order, and the direction of the slow axis of the λ/2 wave plate is approximately 15 with respect to the direction of the transmission axis of the linear polarizer. And the direction of the slow axis of the quarter-wave plate is approximately 75° with respect to the direction of the transmission axis of the linear polarizer.
Example (b): A linear polarizer, a λ/2 wave plate, and a λ/4 wave plate are provided in this order, and the direction of the slow axis of the λ/2 wave plate is approximately 75 with respect to the direction of the transmission axis of the linear polarizer. And the direction of the slow axis of the quarter-wave plate is about 15° with respect to the direction of the transmission axis of the linear polarizer.

A process of sequentially manufacturing an optically anisotropic laminate and a circularly polarizing plate from the optical laminate obtained by the production method of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing an example of the optical laminate obtained by the manufacturing method of the present invention, and FIG. 2 is an example of the optically anisotropic laminate obtained from the optical laminate shown in FIG. 3 is a cross-sectional view schematically showing, and FIG. 3 is a cross-sectional view schematically showing an example of a circularly polarizing plate obtained from the optically anisotropic laminate shown in FIG.

In FIG. 1, an optical layered body 100 includes a substrate 111, a first optically anisotropic layer 121 (λ/4) formed on the surface thereof, an optical alignment layer 131 formed on the surface thereof, and The second optically anisotropic layer 122 (λ/2) formed on the surface is provided. In this example, the first optical stack 121 (λ/4) is a λ/4 wave plate, while the second optical anisotropic layer 122 (λ/2) is a λ/2 wave plate. The optically anisotropic laminate 200 shown in FIG. 2 is obtained by peeling the substrate 111 from the optical laminate 100. The circularly polarizing plate 300 shown in FIG. 3 is obtained by laminating a linear polarizer 141 on the surface of the optically anisotropic laminate 200 shown in FIG. 2 on the second optical anisotropic layer 122 (λ/2) side. It is a thing.

Generally, most of the long linear polarizers that are easily available have a transmission axis in the width direction. In such a circularly polarizing plate 300, the slow axis of the first optically anisotropic layer 121 (λ/4), the slow axis of the second optically anisotropic layer 122 (λ/2), and the linear polarizer are used. Preferred examples of the relationship of the transmission axes are as in the following examples (300-a) and (300-b).

Example (300-a):
Transmission axis direction of linear polarizer: width direction Slow axis direction of first optically anisotropic layer 121 (λ/4): angle formed with width direction about 75°
Slow axis direction of the second optically anisotropic layer 122 (λ/2): an angle formed with the width direction of about 15°

Example (300-b):
Transmission axis direction of linear polarizer: width direction Slow axis direction of first optically anisotropic layer 121 (λ/4): angle formed with width direction of about 15°
Slow axis direction of the second optically anisotropic layer 122 (λ/2): an angle formed with the width direction of about 75°

FIG. 4 is a sectional view schematically showing another example of the optical layered body obtained by the manufacturing method of the present invention, and FIG. 5 is an optically anisotropic layered body obtained from the optical layered body shown in FIG. 6 is a sectional view schematically showing an example, and FIG. 6 is a sectional view schematically showing an example of a circularly polarizing plate obtained from the optically anisotropic laminate shown in FIG.

In FIG. 4, the optical laminated body 400 includes a substrate 111, a first optical anisotropic layer 422 (λ/2) formed on the surface thereof, a photo-alignment layer 131 formed on the surface, and the optical alignment layer 131. The second optically anisotropic layer 421 (λ/4) is formed on the surface. In this example, the first optical stack 422 (λ/2) is a λ/2 wave plate, while the second optically anisotropic layer 421 (λ/4) is a λ/4 wave plate. The optically anisotropic laminate 500 shown in FIG. 5 is obtained by peeling the substrate 111 from the optical laminate 500. The circularly polarizing plate 600 shown in FIG. 6 is obtained by bonding a linear polarizer 141 to the surface of the optically anisotropic laminate 500 shown in FIG. 5 on the first optical anisotropic layer 422 (λ/2) side. It is a thing.

In such a circularly polarizing plate 600, the slow axis of the first optically anisotropic layer 422 (λ/2), the slow axis of the second optically anisotropic layer 421 (λ/4), and the linear polarizer Preferred examples of the relationship of the transmission axes are as in the following examples (600-a) and (600-b).

Example (600-a):
Transmission axis direction of linear polarizer: width direction Slow axis direction of first optically anisotropic layer 422 (λ/2): angle formed with width direction of about 15°
Slow axis direction of the second optically anisotropic layer 421 (λ/4): an angle of approximately 75° with the width direction

Example (600-b):
Transmission axis direction of linear polarizer: width direction Slow axis direction of first optically anisotropic layer 422 (λ/2): angle formed with width direction about 75°
The slow axis direction of the second optically anisotropic layer 421 (λ/4): an angle formed with the width direction of about 15°

Such a circularly polarizing plate can be manufactured by roll-to-roll, and by cutting the long shape in a direction parallel to the longitudinal direction and a direction parallel to the width direction, antireflection of the display device is prevented. Since it can be cut into a rectangular shape applicable as a film, it becomes possible to efficiently manufacture a high-quality circularly polarizing plate.

The circularly polarizing plate of the present invention may have any other layer as required. Examples of the optional layer include an adhesive layer for adhering to other members, a mat layer for improving the slipperiness of the film, a hard coat layer such as an impact-resistant polymethacrylate resin layer, an antireflection layer, an antifouling layer, etc. Are listed.

[10. Organic electroluminescence display device)
An organic electroluminescence display device of the present invention includes the circularly polarizing plate of the present invention. In the organic electroluminescent display device of the present invention, the circularly polarizing plate can function as an antireflection film. That is, by providing the circularly polarizing plate having the above-described configuration on the surface of the display device so that the surface on the linear polarizer side faces the viewing side, light incident from the outside of the device is reflected inside the device. It is possible to suppress emission to the outside of the device, and as a result, it is possible to suppress undesired reduction of glare on the display surface of the display device. Specifically, in the light incident from the outside of the device, only a part of the linearly polarized light passes through the linear polarizer, and then it passes through the optically anisotropic layer to become circularly polarized light. The circularly polarized light referred to here includes elliptically polarized light as long as it is a range in which the antireflection function is substantially exhibited. Circularly polarized light is reflected by a component that reflects light inside the device (a reflective electrode in an organic EL element, etc.), and passes through the optically anisotropic layer again, so that it is a direction orthogonal to the polarization axis of the incident linearly polarized light. It becomes a linearly polarized light having a polarization axis at and does not pass through the linear polarizer. Thereby, the antireflection function is achieved.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples described below, and does not depart from the scope of claims of the present invention and the scope of equivalents thereof. In any case, it may be changed and implemented.
In the following description, "%" and "parts" representing amounts are by weight unless otherwise specified. Further, the operations described below were performed under the conditions of normal temperature and normal pressure unless otherwise specified.

[Measurement method of phase difference value and slow axis direction]
The measurement target is installed on a stage of a polarization analyzer (“AxoScan” manufactured by Axometrics Co., Ltd.), and polar angles are −50° to 50° with respect to 4 azimuth angles (0°, 45°, 90°, 135°). The data was acquired in the range of, and thereby the phase difference value and the slow axis direction were measured.
When the measurement target is a multi-layered product of a stretched base material and another layer, the acquired data is input to a multilayer analysis software ("Multi-Layer Analysis" manufactured by Axometrics Co., Ltd.) to obtain the physical properties of the stretched base material. Is known, and the three-dimensional refractive index and orientation angle of the optically anisotropic layer are calculated as fitting parameters, whereby the retardation value, the slow axis direction, and (when the measurement target is an optical laminate) the The crossing angle between the slow axis of the first optically anisotropic layer and the slow axis of the second optically anisotropic layer was determined.

[Measurement Method of Deviation between Orientation Axis of Substrate and Slow Axis of First Optically Anisotropic Layer]
Before applying the first liquid crystal composition to the substrate, a reference line was drawn on the surface of the substrate opposite to the surface on which the first liquid crystal composition was applied. After forming the first optically anisotropic layer through steps (I) and (II), a reference line was drawn on the surface of the first optically anisotropic layer at a position overlapping with the reference surface of the substrate. Then, the first optically anisotropic layer was transferred to a glass plate via a pressure sensitive adhesive and peeled from the substrate. Then, each of the orientation axis direction of the substrate and the slow axis of the first optically anisotropic layer was measured using AxoScan (manufactured by Axometrics Co., Ltd.), and the substrate, orientation axis direction and reference line on the substrate were measured. The angle formed by and the angle formed by the slow axis of the first optically anisotropic layer and the reference line on the first optically anisotropic layer were determined. From these angles, the deviation between the orientation axis direction of the substrate and the slow axis direction of the first optically anisotropic layer was determined.

〔surface hardness〕
The surface hardness of the optically anisotropic layer and the photo-alignment layer was evaluated by measuring the pencil hardness based on JISK5600-5-4.

[Evaluation of surface scratches]
The surface scratches of the photo-alignment layer and the second optically anisotropic layer were evaluated based on the following evaluation criteria.
Good: There is no streak-like scratch when observed with a polarizing microscope.
Fair: There are some streak-like scratches when observed with a polarizing microscope.
Poor: There are many streak-like scratches when observed with a polarizing microscope.

[Evaluation of coating unevenness]
The coating unevenness of the second optically anisotropic layer was evaluated based on the following evaluation criteria.
Good: There is no unevenness when observed with a polarizing microscope.
Poor: There is unevenness when observed with a polarizing microscope.

[Production Example 1: Base material A before stretching]
Pellets of thermoplastic norbornene resin (manufactured by Nippon Zeon Co., Ltd., trade name “ZEONOR 1420R”, Tg 137° C.) were dried at 100° C. for 5 hours. The dried pellets are fed to an extruder, melted in the extruder, passed through a polymer pipe and a polymer filter, extruded in a sheet form from a T die onto a casting drum, cooled, and then masked with a masking film (FF1025 manufactured by Treteger). It was wound up while being protected to obtain a roll (A) of a base material before stretching having a thickness of 80 μm and a width of 1490 mm.

[Production Example 2: Base material B before stretching]
The thermoplastic norbornene resin pellets were changed to those having a Tg of 126° C. (manufactured by Nippon Zeon Co., Ltd.) and the T-die was changed, in the same manner as in Production Example 1 to prepare a base material before stretching having a thickness of 100 μm and a width of 1490 mm. A roll (B) was obtained.

[Production Example 3: Base material C before stretching]
A thermoplastic norbornene resin pellet having a Tg of 126° C. (manufactured by Nippon Zeon Co., Ltd.) was used, and the T die was changed, in the same manner as in Production Example 1 to prepare a pre-stretch base material having a thickness of 60 μm and a width of 1350 mm. A roll (C) was obtained.

[Production Example 4: Liquid crystal composition A]
Polymerizable liquid crystal compound (trade name "LC242" manufactured by BASF, compound represented by formula (A1)) 24.15 parts, surfactant (trade name "Futgent FTX-209F" manufactured by Neos) 0.12 parts A polymerization initiator (trade name “IRGACURE379”, manufactured by BASF) 0.73 part and a solvent (methyl ethyl ketone) 75.00 parts were mixed to prepare a liquid crystal composition.

[Example 1]
(1-1. Stretched substrate)
The long pre-stretching base material A obtained in Production Example 1 was pulled out from the roll (A), the masking film was continuously peeled off, and the tenter stretching machine was supplied with the orientation angle of the base material in the width direction. Was obliquely stretched so as to be 15°. The stretched base material was wound up while being protected by a new masking film (FF1025, manufactured by Treteger Co., Ltd.) to obtain a stretched base material roll. The slow axis of the obtained stretched base material was 15° with respect to the width direction, Re was 265 nm, and the film thickness was 40 μm. The surface roughness (Ra) of the surface on which the liquid crystal composition was applied was 0.005 μm.

(1-2. Process (I))
The stretched base material was fed out from the roll of the stretched base material obtained in (1-1), and the masking film was continuously peeled off and conveyed. The liquid crystal composition A obtained in Production Example 4 was applied directly to the surface of the conveyed stretched base material on the side where the masking film had been bonded at a room temperature of 25° C. using a die coater. A layer of composition was formed.

(1-3. Step (II))
The layer of the liquid crystal composition formed on the stretched substrate in (1-2) was oriented at 110° C. for 2.5 minutes. Then, in a nitrogen atmosphere (oxygen concentration of 0.1% or less), the back surface of the substrate (the side opposite to the side on which the layer of the liquid crystal composition is formed) is irradiated with ultraviolet rays having an integrated light amount of 1000 mJ/cm ² , The layer of liquid crystal composition was cured. As a result, a homogeneously oriented first optically anisotropic layer having a Re 240 nm and a dry film thickness of 2.2 μm is formed on the stretched substrate, and the (first optically anisotropic layer)/(stretched substrate) layer is formed. A multi-layered product having the constitution was obtained. The deviation between the slow axis direction of the first optically anisotropic layer and the orientation axis direction of the substrate was 1°, and the surface hardness of the first optically anisotropic layer was F.

(1-4. Step (III))
On the surface of the multi-layered product obtained in (1-3) on the side of the first optical anisotropic layer, a photo-alignment material liquid (manufactured by DIC: LIA-02, solid content 1% by weight, solvent 2-butoxyethanol 99). % By weight) and dried at 80° C. for 2 minutes to form a layer of photo-alignment material liquid. After that, the coated surface side of the layer of the photo-alignment material liquid (the side opposite to the optically anisotropic layer side of the layer of the photo-alignment material liquid) is irradiated with linearly polarized ultraviolet light having a wavelength of about 313 nm, and The layer was cured. The polar angle of the irradiation direction was 0° (perpendicular to the irradiation surface), and the azimuth angle of the polarization direction of the linearly polarized ultraviolet light was 75° with respect to the width direction of the base material. The irradiation environment was a room temperature of 25° C. under a nitrogen atmosphere (oxygen concentration of 0.1% or less). The integrated light amount of irradiation was 500 mJ/cm ² . As a result, a photo-alignment layer having a thickness of 0.05 μm was formed, and a multilayer product having a layer structure of (photo-alignment layer)/(first optical anisotropic layer)/(stretched substrate) was obtained. The surface hardness of the photo-alignment layer was B. When the surface of the photo-alignment layer was observed with a polarizing microscope and the state of surface scratches was evaluated, it was determined to be “good” (no streak-like scratches).

(1-5. Step (IV))
The liquid crystal composition A obtained in Production Example 4 was applied onto the surface of the multi-layered product obtained in (1-4) on the photo-alignment layer side at a room temperature of 25° C. using a die coater to give a liquid crystal composition. Layers were formed. The layer of the liquid crystal composition was aligned at 110° C. for 2.5 minutes. Then, in a nitrogen atmosphere (oxygen concentration of 0.1% or less), the coating surface side (the side of the liquid crystal composition layer opposite to the photo-alignment layer) is irradiated with ultraviolet rays of 2000 mJ/cm ² or more to give a liquid crystal composition. The layer was cured. As a result, a homogeneously oriented second optically anisotropic layer having a Re of 145 nm and a dry film thickness of 1.1 μm is formed on the optical orientation layer, and the second optical anisotropic layer/(optical orientation layer)/( An optical laminate having a layer structure of (first optically anisotropic layer)/(stretched substrate) was obtained. The deviation between the slow axis direction of the second optically anisotropic layer and the direction of the photo-alignment layer was 1°, and the surface hardness of the second optically anisotropic layer was HB. When the surface of the second optically anisotropic layer was observed with a polarizing microscope and the state of coating unevenness and surface scratches was evaluated, the coating unevenness was “good” (no unevenness) and the surface scratches were “good” (streak-like scratches). There is a little)).

[Example 2]
(2-1. Stretched substrate)
The long pre-stretched base material B obtained in Production Example 2 is pulled out from the roll (B), the masking film is continuously peeled off, and the tenter stretcher is supplied with the slanted stretch and the subsequent longitudinal stretch. Went to. As a result, the orientation angle of the substrate was 75° with respect to the width direction. The stretched base material was wound up while being protected by a new masking film (FF1025, manufactured by Treteger Co., Ltd.) to obtain a stretched base material roll. The slow axis of the obtained stretched base material was 75° with respect to the width direction, Re was 140 nm, and the film thickness was 57 μm.

(2-2. Steps (I) to (IV))
An optical layered body was manufactured and evaluated by the same operations as in (1-2) to (1-5) of Example 1 except that the following matters were changed. The evaluation results are shown in Tables 1 to 4.
In (1-2), as the stretched base material, the one obtained in (2-1) was used in place of the one obtained in (1-1) of Example 1.
-In (1-3), the integrated light amount of ultraviolet irradiation was changed to 2000 mJ/cm ² .
The coating thickness of the liquid crystal composition in (1-2) was adjusted. As a result, Re of the first optically anisotropic layer obtained in (1-3) was 145 nm, and the dry film thickness was 1.1 μm.
In (1-4), the azimuth angle of the polarization direction of the linearly polarized ultraviolet light was 15° with respect to the width direction of the base material.
-In (1-5), the coating thickness of the liquid crystal composition was adjusted. The Re of the obtained second optically anisotropic layer was 260 nm, and the dry film thickness was 2.2 μm.

[Example 3]
(3-1. Stretched substrate)
The long pre-stretching base material A obtained in Production Example 1 is pulled out from the roll (A), the masking film is continuously peeled off, and the tenter stretching machine is supplied with the diagonal stretching and the subsequent longitudinal stretching continuously. Went to. As a result, the orientation angle of the substrate was 75° with respect to the width direction. The stretched base material was wound up while being protected by a new masking film (FF1025, manufactured by Treteger Co., Ltd.) to obtain a stretched base material roll. The slow axis of the obtained stretched base material was 75° with respect to the width direction, Re was 144 nm, and the film thickness was 54 μm.

(3-2. Steps (I) to (IV))
An optical layered body was manufactured and evaluated by the same operations as in (1-2) to (1-5) of Example 1 except that the following matters were changed. The evaluation results are shown in Tables 1 to 4.
In (1-2), as the stretched base material, instead of the stretched base material obtained in (1-1) of Example 1, the one obtained in (3-1) was used.
-In (1-3), the integrated light amount of ultraviolet irradiation was changed to 1500 mJ/cm ² . Further, the thickness and the like of the obtained first optically anisotropic layer were slightly changed, Re was 245 nm, and the dry film thickness was 2.1 μm.
In (1-4), the azimuth angle of the polarization direction of the linearly polarized ultraviolet light was 15° with respect to the width direction of the base material.
In (1-5), the thickness and the like of the obtained second optically anisotropic layer were slightly changed, Re was 148 nm, and the dry film thickness was 1.2 μm.

[Example 4]
An optical layered body was manufactured and evaluated by the same operation as in Example 1 except that the following matters were changed. The evaluation results are shown in Tables 1 to 4.
In (1-1), the pre-stretch base material C obtained in Production Example 3 was used in place of the pre-stretch base material A obtained in Production Example 1. The slow axis of the obtained stretched substrate was 15° with respect to the width direction, Re was 141 nm, and the film thickness was 25 μm.
In (1-2), as the stretched base material, the one obtained in (4-1) was used instead of the one obtained in (1-1) of Example 1.
In (1-3), the irradiation of ultraviolet rays was performed not on the back surface side of the substrate but on the coating surface side (the side where the liquid crystal composition layer is formed). Further, the integrated light amount was changed to 500 mJ/cm ² .
The coating thickness of the liquid crystal composition in (1-2) was adjusted. As a result, Re of the first optically anisotropic layer obtained in (1-3) was 148 nm, and the dry film thickness was 1.2 μm.
-In (1-5), the coating thickness of the liquid crystal composition was adjusted. The Re of the obtained second optically anisotropic layer was 255 nm, and the dry film thickness was 2.1 μm.

[Example 5]
An optical layered body was manufactured and evaluated by the same operation as in Example 1 except that the following matters were changed. The evaluation results are shown in Tables 1 to 4.
-In (1-3), the integrated light amount of ultraviolet irradiation was changed to 1500 mJ/cm ² . Further, the thickness and the like of the obtained first optically anisotropic layer were slightly changed, Re was 235 nm, and the dry film thickness was 2.1 μm.
-In (1-4), the integrated light amount of linearly polarized ultraviolet light was changed to 1000 mJ/cm ² .
In (1-5), the thickness and the like of the obtained second optically anisotropic layer were slightly changed, Re was 144 nm, and the dry film thickness was 1.1 μm.

[Comparative Example 1]
The same operations as (1-1) to (1-4) of Example 1 were performed except that the following matters were changed, and a multilayer product was obtained and evaluated. However, since the state of the photo-alignment layer was poor, the step corresponding to the step (1-5) of Example 1 was not performed. The evaluation results are shown in Tables 1 to 4.
-In (1-3), the integrated light amount of ultraviolet irradiation was changed to 200 mJ/cm ² , and the irradiation environment was changed to air instead of nitrogen atmosphere. Further, the thickness and the like of the obtained first optically anisotropic layer were slightly changed, Re was 233 nm, and the dry film thickness was 2.1 μm.
In (1-4), the integrated light amount of linearly polarized ultraviolet light was changed to 200 mJ/cm ² , and the irradiation environment was changed to air instead of nitrogen atmosphere.

[Comparative Example 2]
The same operation as in Example 1 was performed except that the following items were changed, and a multilayer product was obtained and evaluated. The evaluation results are shown in Tables 1 to 4.
-In (1-3), the integrated light amount of ultraviolet irradiation was changed to 500 mJ/cm ² .
In (1-4), the integrated light amount of linearly polarized ultraviolet light was changed to 200 mJ/cm ² , and the irradiation environment was changed to air instead of nitrogen atmosphere.

From the results of the examples and the comparative examples, according to the present invention, the surface of each layer is a production method in which the first optically anisotropic layer, the photo-alignment layer, and the second optically anisotropic layer are sequentially formed on the substrate. It can be seen that an optical laminate having few scratches and coating unevenness can be easily produced, and thus a circularly polarizing plate or the like provided with such an optically anisotropic layer can be efficiently produced.

100: Optical laminate 111: Substrate 121 (λ/4): First optical anisotropic layer 131: Photo-alignment layer 122 (λ/2): Second optical anisotropic layer 200: Optical anisotropic laminate 300: Circularly polarizing plate 141: Linear polarizer 400: Optical laminated body 422 (λ/2): First optical anisotropic layer 421 (λ/4): Second optical anisotropic layer 500: Optical anisotropic laminated layer Body 600: circularly polarizing plate

Claims (8)

A method of manufacturing an optical layered body,
A step (I) of directly applying a first liquid crystal composition containing a first liquid crystal compound onto a long substrate to obtain a layer of the first liquid crystal composition,
The first liquid crystal composition is prepared by aligning the first liquid crystal compound in the layer of the first liquid crystal composition, and irradiating the layer of the first liquid crystal composition with an active energy ray under an inert gas atmosphere. (II), in which the first optical anisotropic layer having a pencil hardness of HB or more and 4H or less is cured.
A liquid containing a photo-alignment material is directly applied onto the first optically anisotropic layer to obtain a layer of a liquid containing the photo-alignment material, which is different from the width direction of the substrate in an inert gas atmosphere. Irradiation to the layer of the liquid containing the photo-alignment material by irradiating the layer of the liquid containing the photo-alignment material with polarized ultraviolet light having a polarization direction to form a photo-alignment layer having a pencil hardness of B or more and 4H or less. Step (III), and directly coating the second liquid crystal composition containing the second liquid crystal compound on the photo-alignment layer to obtain a layer of the second liquid crystal composition, and the second liquid crystal. A second optically anisotropic layer, in which the second liquid crystal compound in the composition layer is aligned, and the second liquid crystal composition layer is irradiated with an active energy ray to cure the second liquid crystal composition; Forming step (IV)
Including
The integrated quantity of light irradiation in the step (II) is Ri Der 1000 mJ / cm ² or more, the accumulated amount of irradiation in the step (III) is 500 mJ / cm ² or more, the production method. It is a manufacturing method of the optical laminated body of Claim 1, Comprising:
The manufacturing method, wherein the irradiation polarization direction in the step (III) forms an angle with the width direction of 10 to 20° or 70 to 80°. It is a manufacturing method of the optical laminated body of Claim 1 or 2, Comprising:
The manufacturing method, wherein the total of the integrated light amounts of irradiation in the step (II) and the step (III) is 1500 mJ/cm ² or more. It is a manufacturing method of the optical laminated body of any one of Claims 1-3, Comprising:
The manufacturing method, wherein the integrated light amount of irradiation in the step (III) is 1000 mJ/cm ² or more. It is a manufacturing method of the optical laminated body of any one of Claims 1-4, Comprising:
A manufacturing method using a stretched substrate obtained by stretching a substrate before stretching as the substrate. It is a manufacturing method of the optical laminated body of any one of Claims 1-5, Comprising:
The manufacturing method, wherein the tension of the base material in the step (III) is 100 to 500 N/m. A method of manufacturing a circularly polarizing plate using the optical laminate manufactured by the method according to any one of claims 1 to 6
Peeling the substrate from the optical laminate to obtain an optically anisotropic laminate,
A laminating step of laminating the optically anisotropic laminate and a long linear polarizer with roll-to-roll,
The optically anisotropic laminate has a first optically anisotropic layer, a photo-alignment film, and a second optically anisotropic layer in this order,
The optically anisotropic layer on the side of the optically anisotropic laminate that is bonded to the linear polarizer is a λ/2 wavelength plate,
In the bonding step, the angle formed by the transmission axis of the linear polarizer and the slow axis of the optically anisotropic layer on the side bonded to the linear polarizer is 10 to 20° or 70 to 80°. A method for producing a circularly polarizing plate, comprising laminating the optically anisotropic laminate and the linear polarizer so that A method for manufacturing an organic electroluminescent display device, comprising the circularly polarizing plate manufactured by the method for manufacturing a circularly polarizing plate according to claim 7 .

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