JP6123658B2 - Method for producing optically anisotropic film - Google Patents

Description

  The present invention relates to a method for producing an optically anisotropic film.

  In a flat panel display (FPD), a member including an optically anisotropic film such as a polarizing plate and a retardation plate is used. As such an optically anisotropic film, an optically anisotropic film produced by applying a composition containing a liquid crystal compound to a substrate is known. For example, Patent Document 1 describes an optically anisotropic film formed by applying a composition containing a liquid crystal compound to a substrate subjected to an alignment treatment.

JP 2007-148098 A

  In the conventional method for producing an optically anisotropic film, the film thickness distribution of the optically anisotropic film is high, and the optical characteristics of the optically anisotropic film are uneven due to the film thickness distribution. There has been a demand for a method for producing an optically anisotropic film having a low film thickness distribution.

The present invention includes the following inventions.
[1] A method for producing an optically anisotropic film containing a polymer of vertically aligned liquid crystal compounds,
A method for producing an optically anisotropic film, wherein the steps (1) to (3) are performed in this order.
(1) Step of applying a composition for forming an optically anisotropic film containing a liquid crystal compound and a solvent to a substrate (2) First, infrared rays are applied to the composition for forming an optically anisotropic film applied to a substrate. by blowing hot air to the morphism to step (3) optically anisotropic film forming composition after being irradiated with infrared rays, the optically anisotropic film forming composition was heated to 60 ° C. to 200 DEG ° C. drying Process
[2] The method for producing an optically anisotropic film according to [1], wherein infrared rays are irradiated by an infrared irradiator.
[3] The distance from the infrared irradiator to the composition for forming optical anisotropy applied to the substrate is 1 cm.
The method for producing an optically anisotropic film according to [2], which is in a range of ˜100 cm.
[4] The method for producing an optically anisotropic film according to [2] or [3], wherein the temperature of the infrared irradiator is 40 ° C to 200 ° C.
[5] The production of the optically anisotropic film according to any one of [1] to [4], wherein drying is performed in an atmosphere having a wind speed of 1 m / second to 10 m / second and a temperature of 60 ° C. to 200 ° C. Method.
[6] The vapor pressure of the solvent contained in the composition for forming an optically anisotropic film is 0.01 kPa or more and 0.6 k
The method for producing an optically anisotropic film according to any one of [1] to [5], which is Pa or less.
[7] The method for producing an optically anisotropic film according to any one of [1] to [6], wherein the substrate is a long film roll having a length in the long direction of 100 m or more.
[8] The method for producing an optically anisotropic film according to any one of [1] to [7], wherein the steps (1) to (3) are continuously performed.
[9] The method for producing an optically anisotropic film according to [8], which is carried out while the substrate is conveyed at a speed of 3 to 20 m / min.
[10] An optically anisotropic film obtained by the method for producing an optically anisotropic film according to any one of [1] to [9].
[11] The optically anisotropic film according to [10], wherein the liquid crystal compound is vertically aligned.
[12] The optically anisotropic film according to [10] or [11] for an in-plane switching (IPS) liquid crystal display device.
[13] A retardation film comprising the optically anisotropic film according to any one of [10] to [12].
[14] A polarizing plate comprising the optically anisotropic film according to any one of [10] to [12].
[15] A display device comprising the optically anisotropic film according to any one of [10] to [12].

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of an optically anisotropic film | membrane with a low film thickness distribution can be provided.

It is a schematic diagram which shows an example of the polarizing plate which concerns on this invention. It is a schematic diagram which shows an example of the display apparatus which concerns on this invention.

The method for producing an optically anisotropic film of the present invention includes the following steps (1) to (3) in this order.
(1) Step of applying optically anisotropic film-forming composition containing liquid crystal compound and solvent to substrate (2) Step of irradiating composition for forming optical anisotropy with infrared rays (3) Irradiating with infrared rays Heating the dried composition for forming an optically anisotropic film to 80 to 120 ° C. and drying the composition

<Base material>
The substrate is preferably a resin substrate.
The resin substrate is usually a transparent resin substrate. The transparent resin base material means a base material having translucency capable of transmitting light, particularly visible light, and the translucency is a transmittance of 80% or more with respect to a light beam having a wavelength of 380 to 780 nm. The characteristic which becomes. As the resin substrate, a film is usually used, and a long film roll is preferably used.

  Polyethylene such as polyethylene, polypropylene and norbornene polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylic acid ester; cellulose ester; polyethylene naphthalate; polycarbonate; polysulfone; And sulfone; polyether ketone; polyphenylene sulfide; and polyphenylene oxide. Among them, a substrate made of polyolefin such as polyethylene, polypropylene, norbornene-based polymer is preferable.

  The substrate may be subjected to a surface treatment. Examples of the surface treatment method include a method of treating the surface of the substrate with corona or plasma in an atmosphere of vacuum to atmospheric pressure, a method of laser treating the substrate surface, a method of treating the substrate surface with ozone, A method of saponifying a material surface, a method of flame-treating a substrate surface, a method of applying a coupling agent to the substrate surface, a method of primer-treating the substrate surface, and a reactive monomer or a reactive polymer For example, a graft polymerization method may be used in which the substrate is adhered to the surface of the substrate and then reacted by irradiation with radiation, plasma, or ultraviolet rays. Among these, a method of corona or plasma treatment of the substrate surface in an atmosphere of vacuum to atmospheric pressure is preferable.

  As a method of performing surface treatment of a substrate with corona or plasma, a method of performing surface treatment of the substrate by installing a substrate between opposed electrodes and generating corona or plasma under a pressure near atmospheric pressure. The surface treatment of a substrate by flowing a gas between opposed electrodes, converting the gas into a plasma between the electrodes, and blowing the plasmaized gas onto the substrate, and generating glow discharge plasma under low pressure conditions The method of performing is mentioned.

  Among them, a method of performing a surface treatment of a substrate by setting a substrate between opposed electrodes under a pressure near atmospheric pressure and generating corona or plasma, or flowing a gas between the opposed electrodes, A method is preferred in which the gas is converted into plasma and the plasmaized gas is sprayed onto the substrate. Such surface treatment with corona or plasma is usually performed by a commercially available surface treatment apparatus.

  The base material may have a protective film on the surface opposite to the surface on which the composition for forming an optically anisotropic film is applied. Examples of the protective film include films such as polyethylene, polyethylene terephthalate, polycarbonate, and polyolefin, and films having an adhesive layer on the film. Of these, polyethylene terephthalate is preferred because of its small thermal deformation during drying. By having a protective film on the surface opposite to the surface on which the composition for forming an optically anisotropic film is applied, it is possible to suppress film vibration during substrate transportation and slight vibration of the coated surface. Can improve the uniformity.

  The thickness of the substrate is usually 5 μm to 300 μm, preferably 20 μm to 200 μm.

  The length of the long film roll in the longitudinal direction is usually 10 m or more, preferably 100 m or more, and preferably 3000 m or less. The length in the short direction of the long film roll is usually 0.1 m to 5 m, preferably 0.2 m to 2 m.

<Alignment film>
An alignment film is preferably formed on the surface of the substrate on which the composition for forming an optically anisotropic film is applied.
The alignment film has an alignment regulating force that aligns a liquid crystal compound described later in a desired direction.
The alignment film preferably has a solvent resistance that does not dissolve when the composition for forming an optically anisotropic film is applied, and has heat resistance in heat treatment for removing the solvent or aligning the liquid crystal compound. Examples of the alignment film include an alignment film containing an alignment polymer, a photo-alignment film, and a groove alignment film having an uneven pattern or a plurality of grooves on the surface.

  Such an alignment film facilitates the alignment of the liquid crystal compound. Further, various orientations such as horizontal orientation, vertical orientation, hybrid orientation, and tilt orientation can be controlled depending on the type of the orientation film and rubbing conditions.

  The thickness of the alignment film is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm, more preferably 500 nm or less, and further preferably in the range of 10 nm to 200 nm.

<Alignment film containing orientation polymer>
Examples of the orientation polymer include polyamides and gelatins having an amide bond, polyimides having an imide bond, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinyl, which are hydrolyzed products thereof. Examples include pyrrolidone, polyacrylic acid and polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. Two or more kinds of orientation polymers may be combined.

  The alignment film containing the alignment polymer is usually applied to the substrate with the alignment polymer composition in which the alignment polymer is dissolved in a solvent, or the solvent is removed, or the alignment polymer composition is applied to the substrate. It is obtained by removing the solvent and rubbing.

  Examples of the solvent include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether and other alcohol solvents, ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, Propylene glycol methyl ether acetate, ester solvents such as ethyl lactate, ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, methyl isobutyl ketone, aliphatic hydrocarbon solvents such as pentane, hexane, heptane, toluene, Aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile, ethers such as tetrahydrofuran and dimethoxyethane Agent, and, chloroform, chlorinated hydrocarbon solvents such as chlorobenzene. Two or more solvents may be combined.

  The concentration of the orienting polymer in the orienting polymer composition may be in a range where the orienting polymer is completely dissolved in the solvent. The content of the orientation polymer with respect to the orientation polymer composition is preferably 0.1 to 20% by mass, and more preferably 0.1 to 10% by mass.

  Oriented polymer compositions are commercially available. Examples of the commercially available oriented polymer composition include Sanever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optmer (registered trademark, manufactured by JSR).

  Examples of methods for applying the alignment polymer composition to the substrate include spin coating method, extrusion method, gravure coating method, die coating method, slit coating method, bar coating method, applicator method, etc., flexo method And publicly known methods such as printing methods. When the optically anisotropic film is produced by a roll to roll type continuous production method described later, a printing method such as a gravure coating method, a die coating method, or a flexo method is usually employed as the coating method.

  Examples of the method for removing the solvent contained in the oriented polymer composition include natural drying, ventilation drying, heat drying, vacuum drying, and a combination thereof. 10-250 degreeC is preferable and, as for drying temperature, 25-200 degreeC is more preferable. The drying time is preferably 5 seconds to 60 minutes, more preferably 10 seconds to 30 minutes, although it depends on the type of solvent.

  The coating film formed from the orientation polymer composition may be rubbed. By performing the rubbing treatment, an alignment regulating force can be imparted to the coating film.

Examples of the rubbing treatment include a method in which a rubbing cloth is wound and the coating film is brought into contact with a rotating rubbing roll.
If masking is performed when the rubbing treatment is performed, a plurality of regions (patterns) having different orientation directions can be formed in the alignment film.

<Photo-alignment film>
The photo-alignment film is usually obtained by applying a photo-alignment film-forming composition containing a polymer or monomer having a photoreactive group and a solvent to a substrate and irradiating with polarized light (preferably polarized UV). . The photo-alignment film can arbitrarily control the direction of the alignment regulating force by selecting the polarization direction of the polarized light to be irradiated.

  The photoreactive group refers to a group that generates alignment ability when irradiated with light. Specific examples include groups that are involved in photoreactions that are the origin of alignment ability, such as alignment-induced reactions, isomerization reactions, photodimerization reactions, photocrosslinking reactions, or photodecomposition reactions of molecules generated by light irradiation. Among these, a group involved in the photodimerization reaction or the photocrosslinking reaction is preferable in terms of excellent orientation. As the photoreactive group, an unsaturated bond, particularly a group having a double bond is preferable, and a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), and nitrogen-nitrogen. A group having at least one selected from the group consisting of a double bond (N═N bond) and a carbon-oxygen double bond (C═O bond) is particularly preferred.

  Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C═N bond include groups having a structure such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.

  Among them, cinnamoyl is preferable in that a photoreactive group involved in the photodimerization reaction is preferable, and the amount of polarized light irradiation necessary for alignment is relatively small, and a photoalignment film excellent in thermal stability and temporal stability is easily obtained. Groups and chalcone groups are preferred. As the polymer having a photoreactive group, a polymer having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

  By applying the composition for forming a photo-alignment film on the substrate, the photo-alignment inducing layer can be formed on the substrate. Examples of the solvent contained in the composition include the same solvents as those contained in the orientation polymer composition described above, and can be selected according to the solubility of the polymer or monomer having a photoreactive group.

  The content of the polymer or monomer having a photoreactive group in the composition for forming a photo-alignment film can be adjusted by the type of the polymer or monomer and the thickness of the target photo-alignment film, and should be at least 0.2% by mass. Is preferable, and the range of 0.3 to 10% by mass is more preferable. As long as the properties of the photo-alignment film are not significantly impaired, the composition for forming a photo-alignment film may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer.

  Examples of the method for applying the composition for forming a photo-alignment film to a substrate include the same methods as the method for applying the alignment polymer composition to a substrate. Examples of the method for removing the solvent from the applied composition for forming a photo-alignment film include the same method as the method for removing the solvent from the oriented polymer composition.

  In order to irradiate polarized light, even in the form of irradiating polarized light directly to the composition from which the solvent is removed from the composition for forming a photo-alignment film applied on the substrate, the polarized light is irradiated from the substrate side and transmitted. It is also possible to irradiate. The polarized light is preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength region where the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) in the wavelength range of 250 nm to 400 nm is particularly preferable. Examples of the light source for irradiating the polarized light include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF, and the like. Among these, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and a metal halide lamp are preferable because of high emission intensity of ultraviolet rays having a wavelength of 313 nm. By irradiating light from the light source through an appropriate polarizing layer, polarized UV can be irradiated. Examples of the polarizing layer include polarizing prisms such as polarizing filters, Glan Thompson, and Granteller, and wire grid type polarizing layers.

  If masking is performed when polarized light irradiation is performed, a plurality of regions (patterns) having different orientation directions can be formed on the alignment film.

<Grubb alignment film>
The groove alignment film is a film having a concavo-convex pattern or a plurality of grooves (grooves) on the film surface. When liquid crystal molecules are placed in a film having a plurality of linear grooves arranged at equal intervals, the liquid crystal molecules are aligned in the direction along the groove.

  As a method for obtaining a groove alignment film, a method of forming a concavo-convex pattern by performing development and rinsing after exposure through an exposure mask having a pattern-shaped slit on the photosensitive polyimide film surface, a plate having grooves on the surface Forming a pre-cured UV curable resin layer on a sheet-shaped master, transferring the resin layer to the base material, and then curing, and a plurality of grooves in the pre-cured UV curable resin film formed on the base material For example, a method may be used in which a roll-shaped master having a surface is pressed to form irregularities and then cured. Specific examples include the methods described in JP-A-6-34976 and JP-A-2011-242743.

  Among the above methods, a method is preferred in which a roll-shaped master having a plurality of grooves is pressed against the surface of the UV-cured resin layer before curing to form irregularities and then cured. As the roll master, stainless steel (SUS) is preferable from the viewpoint of durability.

Examples of the UV curable resin include monofunctional acrylates, polyfunctional acrylates, and mixtures thereof.
The monofunctional acrylate is a group selected from the group consisting of an acryloyloxy group (CH ₂ ═CH—COO—) and a methacryloyloxy group (CH ₂ ═C (CH ₃ ) —COO—) (hereinafter referred to as (meth) acryloyloxy). A compound that may be referred to as a group). Moreover, (meth) acrylate means an acrylate or a methacrylate.

  Monofunctional acrylates having one (meth) acryloyloxy group include alkyl (meth) acrylates having 4 to 16 carbon atoms, β-carboxyalkyl (meth) acrylates having 2 to 14 carbon atoms, and alkylation having 2 to 14 carbon atoms. Examples include phenyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, and isobornyl (meth) acrylate.

  The polyfunctional acrylate is a compound having 2 or more (meth) acryloyloxy groups, and a compound having 2 to 6 (meth) acryloyloxy groups is preferable.

  The polyfunctional acrylate having two (meth) acryloyloxy groups includes 1,3-butanediol di (meth) acrylate; 1,3-butanediol (meth) acrylate; 1,6-hexanediol di (meth) acrylate Ethylene glycol di (meth) acrylate; diethylene glycol di (meth) acrylate; neopentyl glycol di (meth) acrylate; triethylene glycol di (meth) acrylate; tetraethylene glycol di (meth) acrylate; polyethylene glycol diacrylate; bisphenol A Bis (acryloyloxyethyl) ether; ethoxylated bisphenol A di (meth) acrylate; propoxylated neopentyl glycol di (meth) acrylate; ethoxylated neopentylglycol Di (meth) acrylate and 3-methyl-pentanediol di (meth) acrylate.

As the polyfunctional acrylate having 3 to 6 (meth) acryloyloxy groups,
Trimethylolpropane tri (meth) acrylate; pentaerythritol tri (meth) acrylate; tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; ethoxylated trimethylolpropane tri (meth) acrylate; propoxylated trimethylolpropane tri ( Pentaerythritol tetra (meth) acrylate; dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate; tripentaerythritol tetra (meth) acrylate; tripentaerythritol penta (meth) acrylate; tripenta Erythritol hexa (meth) acrylate; tripentaerythritol hepta (meth) acrylate; tripentaerythritol o Data (meth) acrylate;
Reaction product of pentaerythritol tri (meth) acrylate and acid anhydride; Reaction product of dipentaerythritol penta (meth) acrylate and acid anhydride;
A reaction product of tripentaerythritol hepta (meth) acrylate and an acid anhydride;
Caprolactone-modified trimethylolpropane tri (meth) acrylate; caprolactone-modified pentaerythritol tri (meth) acrylate; caprolactone-modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; caprolactone-modified pentaerythritol tetra (meth) acrylate; caprolactone-modified Dipentaerythritol penta (meth) acrylate; caprolactone-modified dipentaerythritol hexa (meth) acrylate; caprolactone-modified tripentaerythritol tetra (meth) acrylate; caprolactone-modified tripentaerythritol penta (meth) acrylate; caprolactone-modified tripentaerythritol hexa (meth) ) Acrylate; caprolactone-modified tripentaerys Tall hepta (meth) acrylate; caprolactone-modified tripentaerythritol octa (meth) acrylate; reaction product of caprolactone-modified pentaerythritol tri (meth) acrylate and acid anhydride; caprolactone-modified dipentaerythritol penta (meth) acrylate and acid anhydride And the reaction product of caprolactone-modified tripentaerythritol hepta (meth) acrylate and acid anhydride.
The caprolactone modification means that a ring-opened product of caprolactone or a ring-opened polymer is introduced between the alcohol-derived site of the (meth) acrylate compound and the (meth) acryloyloxy group.

  Multifunctional acrylates are commercially available. Commercially available products include A-DOD-N, A-HD-N, A-NOD-N, APG-100, APG-200, APG-400, A-GLY-9E, A-GLY-20E, A-TMM. -3, A-TMPT, AD-TMP, ATM-35E, A-TMMT, A-9550, A-DPH, HD-N, NOD-N, NPG, TMPT [Shin Nakamura Chemical Co., Ltd.], "ARONIX M -220 "," M-325 "," M-240 "," M-270 "," M-309 "," M-310 "," M-321 "," M-350 " "M-360", "M-305", "M-306", "M-450", "M-451", "M-408", "M-400", "M-402", "M-403", "M-404", "M-405", "M-" 06 "[Toa Gosei Co., Ltd.]," EBECRYL11 "," 145 "," 150 "," 40 "," 140 "," 180 ", DPGDA, HDDA, TPGDA, HPNDA, PETIA, PETRA , TMPTA, TMPEOTA, DPHA, EBECRYL series [Daicel Cytec Co., Ltd.] and the like.

  In order to obtain an orientation with a small alignment disorder, the width of the convex portion of the groove alignment film is preferably 0.05 μm to 5 μm, and the width of the concave portion is preferably 0.1 μm to 5 μm. The depth is preferably 2 μm or less, and preferably 0.01 μm to 1 μm.

<Composition for optical anisotropic film formation>
The composition for forming an optically anisotropic film includes a liquid crystal compound and a solvent.

<Liquid crystal compound>
Examples of the liquid crystal compound include a compound containing a group represented by the formula (X) (hereinafter sometimes referred to as “compound (X)”). One type of liquid crystal compound may be used, or a plurality of compounds having different structures may be combined.
^{P 11 -B 11 -E 11 -B 12} -A 11 -B 13 - (X)
[In formula (X), P ¹¹ represents a hydrogen atom or a polymerizable group.
A ¹¹ represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and divalent aromatic hydrocarbon group is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group. The hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.
B ¹¹ is —O—, —S—, —CO—O—, —O—CO—, —O—CO—O—, —CO—NR ¹⁶ —, —NR ¹⁶ —CO—, —CO—, -CS- or a single bond is represented. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
B ¹² and ^{B 13} are each _{independently, -C≡C -, - CH = CH} -, - CH 2 -CH 2 -, - O -, - S -, - C (= O) -, - C ( = O) -O-, -OC (= O)-, -O-C (= O) -O-, -CH = N-, -N = CH-, -N = N-, -C ( ═O) —NR ¹⁶ —, —NR ¹⁶ —C (═O) —, —OCH ₂ —, —OCF ₂ —, —CH ₂ O—, —CF ₂ O—, —CH═CH—C (═O ) —O—, —O—C (═O) —CH═CH— or a single bond.
E ¹¹ represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and hydrogen contained in the alkoxy group The atom may be substituted with a halogen atom. In addition, —CH ₂ — constituting the alkanediyl group may be replaced by —O— or —CO—. ]

The number of carbon atoms of the divalent aromatic hydrocarbon group and divalent alicyclic hydrocarbon group represented by A ¹¹ is preferably in the range of 3 to 18, more preferably in the range of 5 to 12. It is preferably 5 or 6, and particularly preferably. A ¹¹ is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

The alkanediyl group having 1 to 12 carbon atoms represented by E ^11, an alkanediyl group having 1 to 12 carbon atoms and is preferably linear. —CH ₂ — constituting the alkanediyl group having 1 to 12 carbon atoms may be replaced by —O—.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane -1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group and dodecane-1,12- A linear alkanediyl group having 1 to 12 carbon atoms such as a diyl group; —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —, —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —O—; CH ₂ —CH ₂ — and —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —O—CH ₂ —CH ₂ — and the like can be mentioned.
B ¹¹ is preferably —O—, —S—, —CO—O—, or —O—CO—, and more preferably —CO—O—.
B ¹² and B ¹³ are each independently —O—, —S—, —C (═O) —, —C (═O) —O—, —O—C (═O) —, —O. —C (═O) —O— is preferable, and —O— or —O—C (═O) —O— is more preferable.

［式（Ｐ−１１）〜（Ｐ−１５）中、
Ｒ^１７〜Ｒ^２１はそれぞれ独立に、炭素数１〜６のアルキル基または水素原子を表わす。］ P ¹¹ is preferably a polymerizable group. As the polymerizable group represented by P ¹¹ , a radical polymerizable group or a cationic polymerizable group is preferable in that it easily undergoes a photopolymerization reaction, and since it is easy to handle and also easy to produce a liquid crystal compound, The polymerizable group is preferably a group represented by the following formula (P-11) to formula (P-15).

[In the formulas (P-11) to (P-15),
R ^{17 to} R ²¹ each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. ]

Specific examples of the groups represented by formula (P-11) to formula (P-13) include groups represented by the following formula (P-16) to formula (P-20).

P ¹¹ is preferably a group represented by formula (P-14) to formula (P-20), and more preferably a vinyl group, a p-stilbene group, an epoxy group, or an oxetanyl group.
More preferably, the group represented by P ¹¹ -B ^11- is an acryloyloxy group or a methacryloyloxy group.

Examples of compound (X) include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI).
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -B ¹⁶ -E ¹² -B ¹⁷ -P ¹² (I)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -F ¹¹ (II)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -E ¹² -B ¹⁷ -P ¹² (III)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -F ¹¹ (IV)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -E ¹² -B ¹⁷ -P ¹² (V)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -F ¹¹ (VI)
(Where
A ^{12 to} A ¹⁴ are each independently synonymous with A ¹¹ , B ^{14 to} B ¹⁶ are each independently synonymous with B ¹² , B ¹⁷ is synonymous with B ¹¹ , and E ¹² is E ¹¹ is synonymous.
F ¹¹ is a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group. Represents a group (—SO ₃ H), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom, and —CH ₂ — constituting the alkyl group and the alkoxy group is replaced by —O—. Also good.

Specific examples of the liquid crystal compound include “3.8.6 Network (fully cross-linked type)” and “6.5” of Liquid Crystal Handbook (Edited by Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd., October 30, 2000). .1 Liquid Crystal Material b. Polymerizable Nematic Liquid Crystal Material ”, JP 2010-31223 A, JP 2010-270108 A, JP 2011-6360 A, and JP 2011-207765 A The liquid crystal compound is mentioned.
The liquid crystal compound preferably has a polymerizable group. Examples of the polymerizable group include the polymerizable group represented by P ¹¹ described above.

  Specific examples of the compound (X) include the following formula (I-1) to formula (I-4), formula (II-1) to formula (II-4), formula (III-1) to formula (III- 26), compounds represented by formula (IV-1) to formula (IV-26), formula (V-1) to formula (V-2), and formula (VI-1) to formula (VI-6). It is done. In the following formulae, k1 and k2 each independently represents an integer of 2 to 12. These compounds (X) are preferable from the viewpoint of easy synthesis or availability.

  The content of the liquid crystal compound in the composition for forming an optically anisotropic film is usually 5 to 50 parts by weight, preferably 10 to 30 parts by weight with respect to 100 parts by weight of the composition for forming an optically anisotropic film. is there.

<Solvent>
The solvent is preferably an organic solvent capable of dissolving the constituent components of the optically anisotropic film forming composition such as a liquid crystal compound, and the solvent capable of dissolving the constituent components of the optically anisotropic film forming composition such as the liquid crystal compound. In addition, a solvent that is inert to the polymerization reaction of the liquid crystal compound is more preferable.
Specifically, alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, phenol; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, Ester solvents such as propylene glycol methyl ether acetate, ethyl lactate, butyl propionate, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, isoamyl acetate, ethyl acetoacetate, ethyl 3-ethoxypropionate; acetone, methyl ethyl ketone, cyclopentanone Ketone solvents such as cyclohexanone, methyl amyl ketone, methyl isobutyl ketone, N-methyl-2-pyrrolidinone; Non-chlorinated aliphatic hydrocarbon solvents such as hexane and heptane; Non-chlorinated aromatic hydrocarbon solvents such as toluene and xylene; Nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; Chlorine such as chloroform and chlorobenzene Hydrocarbon hydrocarbon solvent. Two or more organic solvents may be used in combination.
Alcohol solvents, ester solvents, ketone solvents, non-chlorinated aliphatic hydrocarbon solvents and non-chlorinated aromatic hydrocarbon solvents are preferred. Further, a solvent having a vapor pressure of 0.01 kPa to 0.6 kPa is preferable. Solvents having a vapor pressure in such a range include butyl cellosolve, γ-butyrolactone, propylene glycol 1-monomethyl ether 2-acetate, ethyl lactate, butyl propionate, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, isoamyl acetate, aceto Examples include ethyl acetate, ethyl 3-ethoxypropionate, cyclohexanone, and N-methyl-2-pyrrolidinone.

  As for content of a solvent, 10-10000 mass parts is preferable with respect to 100 mass parts of solid content, More preferably, it is 100-5000 mass parts. The solid concentration in the composition for forming an optically anisotropic film is preferably 2 to 50% by mass, more preferably 5 to 50% by mass. The “solid content” means the total of components excluding the solvent from the composition for forming an optically anisotropic film.

  The composition for forming an optically anisotropic film may contain a polymerization initiator, a polymerization inhibitor, a photosensitizer, a leveling agent, a chiral agent, a reactive additive, and the like in addition to the liquid crystal compound and the solvent. When the liquid crystal compound has a polymerizable group, the composition for forming an optically anisotropic film preferably contains a polymerization initiator.

<Polymerization initiator>
As the polymerization initiator, a photopolymerization initiator is preferable, and a photopolymerization initiator that generates radicals by light irradiation is preferable.
Examples of the photopolymerization initiator include benzoin compounds, benzophenone compounds, benzyl ketal compounds, α-hydroxyketone compounds, α-aminoketone compounds, α-acetophenone compounds, triazine compounds, iodonium salts, and sulfonium salts. Specifically, Irgacure 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369 (all made by Ciba Japan Co., Ltd.), Sake All BZ, Sake All Z, Sake All BEE (all all Seiko) Chemical Co., Ltd.), kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow), Adekaoptomer SP-152, Adekaoptomer SP-170 (all above, ADEKA Corporation Product), TAZ-A, TAZ-PP (manufactured by Nippon Siebel Hegner) and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.). Of these, α-acetophenone compounds are preferable, and examples of α-acetophenone compounds include 2-methyl-2-morpholino-1- (4-methylsulfanylphenyl) propan-1-one, 2-dimethylamino-1- (4-morpholino Phenyl) -2-benzylbutan-1-one, 2-dimethylamino-1- (4-morpholinophenyl) -2- (4-methylphenylmethyl) butan-1-one and the like, more preferably 2- And methyl-2-morpholino-1- (4-methylsulfanylphenyl) propan-1-one and 2-dimethylamino-1- (4-morpholinophenyl) -2-benzylbutan-1-one. Examples of commercially available products of α-acetophenone compounds include Irgacure 369, 379EG, 907 (above, manufactured by BASF Japan Ltd.), Sequol BEE (manufactured by Seiko Chemical Co., Ltd.), and the like.

  In order not to disturb the alignment of the liquid crystal compound, the content of the polymerization initiator is usually 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the liquid crystal compound. Part by mass.

<Polymerization inhibitor>
Polymerization inhibitors include hydroquinones having substituents such as hydroquinone and alkyl ethers; catechols having substituents such as alkyl ethers such as butylcatechol; pyrogallols, 2,2,6,6-tetramethyl-1- Radical scavengers such as piperidinyloxy radicals; thiophenols; β-naphthylamines and β-naphthols.
In order not to disturb the alignment of the liquid crystal compound, the content of the polymerization inhibitor is usually 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the liquid crystal compound. .

<Photosensitizer>
Examples of the photosensitizer include xanthones such as xanthone and thioxanthone; anthracene having a substituent such as anthracene and alkyl ether; phenothiazine; and rubrene.
By using a photosensitizer, the sensitivity of the photopolymerization initiator can be increased. Content of a photosensitizer is 0.1-30 mass parts normally with respect to 100 mass parts of liquid crystal compounds, Preferably it is 0.5-10 mass parts.

<Leveling agent>
Examples of the leveling agent include organic modified silicone oil-based, polyacrylate-based and perfluoroalkyl-based leveling agents. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all are manufactured by Toray Dow Corning Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all, Momentive Performance Materials Japan GK) ), Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all of which are Sumitomo Three) Manufactured by M. Co., Ltd.), MegaFace (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F- 470, F-477, F-479, F-482, F-482 (all of which are manufactured by DIC Corporation), Ftop (trade name) EF301, EF303, EF351, EF352 ( As described above, all manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd.), Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40 SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.), trade name E1830, E5844 (manufactured by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and YK-361N (both trade name: BM Chemie Co., Ltd.) and the like. Two or more leveling agents may be combined.

  By using a leveling agent, a smoother optically anisotropic film can be formed. Moreover, the fluidity | liquidity of the composition for optical anisotropic film formation can be controlled in the manufacture process of an optical anisotropic film. Content of a leveling agent is 0.1-30 mass parts normally with respect to 100 mass parts of liquid crystal compounds, Preferably it is 0.1-10 mass parts.

<Chiral agent>
Examples of the chiral agent include known chiral agents (for example, liquid crystal device handbook, Chapter 3-4-3, TN, chiral agent for STN, 199 pages, edited by Japan Society for the Promotion of Science, 142nd Committee, 1989). It is done.
The chiral agent generally contains an asymmetric carbon atom, but an axially asymmetric compound or a planar asymmetric compound containing no asymmetric carbon atom can also be used as the chiral agent. Examples of the axial asymmetric compound or the planar asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof.
Specifically, JP 2007-269640 A, JP 2007-269639 A, JP 2007-176870 A, JP 2003-13787 A, JP 2000-51596 A, JP 2007-169178 A. No. 9 and Japanese National Patent Publication No. 9-506088, and palocolor (registered trademark) LC756 manufactured by BASF Japan Ltd. is preferable.
In order not to disturb the orientation of the liquid crystal compound, the content of the chiral agent is usually 0.1 to 30 parts by mass, preferably 1.0 to 25 parts by mass with respect to 100 parts by mass of the liquid crystal compound.

<Reactive additive>
The reactive additive is preferably one having a carbon-carbon unsaturated bond and an active hydrogen reactive group in the molecule. The “active hydrogen reactive group” as used herein is a group reactive to a group having active hydrogen such as a carboxyl group (—COOH), a hydroxyl group (—OH), an amino group (—NH ₂ ), and the like. Typical examples are epoxy group, oxazoline group, carbodiimide group, aziridine group, imide group, isocyanate group, thioisocyanate group, maleic anhydride group and the like.

  In the reactive additive, it is preferable that at least two active hydrogen reactive groups are present. In this case, a plurality of active hydrogen reactive groups may be the same or different.

  The carbon-carbon unsaturated bond that the reactive additive has may be a carbon-carbon double bond, a carbon-carbon triple bond, or a combination thereof, and is preferably a carbon-carbon double bond. Among these, it is preferable that the reactive additive contains a vinyl group and / or a (meth) acryl group. Further, the active hydrogen reactive group is preferably at least one selected from the group consisting of an epoxy group, a glycidyl group and an isocyanate group, and a reactive additive having an acrylic group and an isocyanate group is particularly preferable. .

  Specific examples of reactive additives include compounds having (meth) acrylic groups and epoxy groups, such as methacryloxyglycidyl ether and acryloxyglycidyl ether; (meth) acrylic groups and oxetane, such as oxetane acrylate and oxetane methacrylate. A compound having a group; a compound having a (meth) acryl group and a lactone group, such as lactone acrylate and lactone methacrylate; a compound having a vinyl group and an oxazoline group, such as vinyl oxazoline and isopropenyl oxazoline; isocyanate methyl acrylate Of compounds having (meth) acrylic groups and isocyanate groups, such as isocyanate methyl methacrylate, 2-isocyanate ethyl acrylate and 20 isocyanate ethyl methacrylate. Ma and the like. Moreover, the compound etc. which have vinyl groups, vinylene groups, and acid anhydrides, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride, are mentioned. Among these, methacryloxy glycidyl ether, acryloxy glycidyl ether, isocyanate methyl acrylate, isocyanate methyl methacrylate, vinyl oxazoline, 2-isocyanate ethyl acrylate, 2-isocyanate ethyl methacrylate and the above oligomers are preferred, isocyanate methyl acrylate, 2-isocyanate ethyl acrylate and the aforementioned oligomers are particularly preferred.

［式（Ｙ）中、
ｎは１〜１０までの整数を表わし、Ｒ^１’は、炭素数２〜２０の２価の脂肪族又は脂環式炭化水素基、或いは炭素数５〜２０の２価の芳香族炭化水素基を表わす。各繰り返し単位にある２つのＲ^２’は、一方が−ＮＨ−であり、他方が＞Ｎ−Ｃ（＝Ｏ）−Ｒ^３’で示される基である。Ｒ^３’は、水酸基又は炭素−炭素不飽和結合を有する基を表す。
式（Ｙ）中のＲ^３’のうち、少なくとも１つのＲ^３’は炭素−炭素不飽和結合を有する基である。］ This preferable reactive additive is represented by the following formula (Y).

[In the formula (Y),
n represents an integer of 1 to 10, and R ^{1 ′} is a divalent aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 5 to 20 carbon atoms. Represents. Two R ^{2 ′ in} each repeating unit is a group represented by one of —NH— and the other of> N—C (═O) —R ^{3 ′} . R ^{3 ′} represents a group having a hydroxyl group or a carbon-carbon unsaturated bond.
Of R ^{3 ′} in formula (Y), at least one R ^{3 ′} is a group having a carbon-carbon unsaturated bond. ]

化合物（ＹＹ）には、市販品をそのまま又は必要に応じて精製して用いることができる。市販品としては、例えば、Ｌａｒｏｍｅｒ（登録商標）ＬＲ−９０００（ＢＡＳＦ社製）等が挙げられる。 Among the reactive additives represented by the formula (Y), a compound represented by the following formula (YY) (hereinafter, sometimes referred to as “compound (YY)”) is particularly preferred (where n is as defined above). The same meaning).

As the compound (YY), a commercially available product can be used as it is or after purification as necessary. Examples of commercially available products include Laromer (registered trademark) LR-9000 (manufactured by BASF).

  Content of a reactive additive is 0.1-30 mass parts normally with respect to 100 mass parts of liquid crystal compounds, Preferably it is 0.1-5 mass parts.

<Application>
Examples of the method for applying the composition for forming an optically anisotropic film to a substrate include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a slit coating method, and a die coating method. Moreover, the method of apply | coating using coaters, such as a dip coater, a bar coater, a spin coater, etc. are mentioned. Among these, a CAP coating method, an ink jet method, a dip coating method, a slit coating method, a die coating method, and a coating method using a bar coater are preferable because they can be continuously applied in the RolltoRoll format. In the case of coating in the RolltoRoll format, an alignment film can be formed on the substrate, and the composition for forming an optical anisotropic film can be continuously applied onto the obtained alignment film.

<Infrared irradiation>
Infrared rays in this specification are electromagnetic waves of 0.75 μm to 1000 μm. The maximum wavelength of infrared rays in the present invention is preferably 3 μm to 1000 μm, more preferably 10 μm to 1000 μm, and further preferably 15 μm to 1000 μm.

  Infrared rays are usually emitted by an infrared irradiator. Examples of the infrared irradiator include an electric type, a heat medium type, and a gas type heater, and preferably an electric type. Specific examples include electric far infrared heaters and heat medium far infrared heaters manufactured by Noritake Company Limited.

The infrared irradiation is preferably performed while keeping the distance between the above-described infrared irradiator and the applied optically anisotropic film forming composition constant. Here, the constant distance means a distance in the range of the average distance ± 20%.
The distance between the infrared ray source of the infrared irradiator and the applied composition for forming an optically anisotropic layer when irradiating infrared rays is usually 1 cm to 100 cm, preferably 5 cm to 50 cm, more preferably. Is 10 cm to 30 cm, more preferably 10 cm to 15 cm.
The irradiation time is usually 5 seconds to 5 minutes, preferably 10 seconds to 2 minutes, and more preferably 15 seconds to 1 minute. Here, the irradiation time means an integration time.

  In the infrared irradiation, the temperature of the infrared source of the infrared irradiator is usually 40 to 200 ° C, preferably 50 to 150 ° C, more preferably 60 to 120 ° C.

It is preferable that a part of the solvent contained in the composition for forming an optically anisotropic film is removed by irradiating the composition for forming an optically anisotropic film applied to the substrate with infrared rays.
The solid content concentration of the composition for forming an optically anisotropic film after being irradiated with infrared rays is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and further preferably 20 to 25% by mass. %.

<Heat drying>
Heat drying is usually performed by applying hot air to the composition for forming an optically anisotropic film irradiated with infrared rays.
The wind speed of the hot air is usually 1 m / sec to 10 m / sec, preferably 2.5 m / sec to 5 m / sec.
The temperature of the hot air is preferably 60 to 200 ° C, more preferably 70 to 150 ° C, and further preferably 80 to 120 ° C. The drying time is usually 10 seconds to 60 minutes, preferably 30 seconds to 30 minutes, although it depends on the type of solvent.

The applied optically anisotropic film forming composition is dried by heating, the solvent is removed, and the liquid crystal compound contained in the optically anisotropic film forming composition is usually aligned by transferring to the liquid crystal phase. To do.
When the liquid crystal compound has a polymerizable group, the aligned liquid crystal compound can be polymerized and cured to obtain an optically anisotropic film. The optically anisotropic film in which the liquid crystal compound is polymerized is not easily affected by a change in birefringence due to heat because the orientation of the liquid crystal compound is fixed.

  Photopolymerization is preferred as a method for polymerizing the liquid crystal compound. According to photopolymerization, since the polymerization can be carried out at a low temperature, the selection range of the resin substrate to be used is widened from the viewpoint of heat resistance. The photopolymerization reaction is usually performed by irradiating visible light, ultraviolet light, or laser light, and preferably by irradiating ultraviolet light.

  The time for irradiation with light is usually 5 seconds to 10 minutes, preferably 5 seconds to 2 minutes, more preferably 5 seconds to 1 minute, and further preferably 5 seconds to 30 seconds. If it is the said range, the optically anisotropic film excellent in transparency can be obtained.

In the production method of the present invention, the steps (1) to (3) are preferably performed continuously.
Under the present circumstances, it is preferable to perform process (1)-(3), conveying a base material at the speed | rate of 3-20 m / min.

Thus, an optically anisotropic film produced by the production method of the present invention (hereinafter sometimes referred to as the present optically anisotropic film) is obtained.
The present optically anisotropic film may be laminated with a base material, or may be peeled off from the base material and bonded to another optical film or the like.

  The thickness of the optically anisotropic film can be adjusted as appropriate depending on the application, but is preferably 0.1 μm to 10 μm, and more preferably 0.2 μm to 5 μm from the viewpoint of reducing photoelasticity.

  The film thickness distribution of the optically anisotropic film is preferably 2.5% or less, more preferably 2.0% or less. A lower film thickness distribution is preferable because in-plane optical characteristics become uniform.

The haze value of the optically anisotropic film is preferably 1.5% or less, more preferably 1.2% or less, still more preferably 0.5% or less, and particularly preferably 0.25%. It is as follows. A lower haze value means higher transparency.
The haze value can be measured with a commercially available haze meter, and examples of the haze meter include a haze meter (model HZ-2) manufactured by Suga Test Instruments Co., Ltd.

The alignment state of the liquid crystal compound includes horizontal alignment, vertical alignment, hybrid alignment, tilted alignment, and the like, and the vertical alignment is preferable. The optically anisotropic film preferably contains a polymer of vertically aligned liquid crystal compounds.
Expressions such as horizontal and vertical represent the alignment direction of the major axis of the liquid crystal compound with respect to the substrate surface. Vertical alignment means having the long axis of the liquid crystal compound in a direction perpendicular to the substrate surface. Vertical here means 90 ° ± 20 °.

The alignment state varies depending on the properties of the alignment film and the liquid crystal compound, and the combination can be arbitrarily selected. For example, if the alignment film is a material that develops horizontal alignment as an alignment regulating force, the liquid crystal compound can form horizontal alignment or hybrid alignment, and if the alignment film is a material that expresses vertical alignment, the liquid crystal compound can be aligned vertically or A tilted orientation can be formed.
The alignment regulating force can be arbitrarily adjusted according to the surface state and rubbing conditions when the alignment film is an alignment film containing an alignment polymer, and can be arbitrarily adjusted according to polarized light irradiation conditions and the like in the case of a photo alignment film. Is possible. In addition, the orientation can be controlled by selecting physical properties such as surface tension and liquid crystallinity of the liquid crystal compound.

  When the liquid crystal compound exhibits a liquid crystal phase such as a nematic phase, it has birefringence due to monodomain alignment.

  A plurality of the optical anisotropic films may be laminated, or may be combined with other films. Laminating a plurality of the present optical anisotropic films having different alignment states of the liquid crystal compound, or combining the present optical anisotropic film and another film, a viewing angle compensation film, a viewing angle widening film, an antireflection film, It can be used as a polarizing plate, a circularly polarizing plate, an elliptically polarizing plate or a brightness enhancement film.

The optically anisotropic film can change the optical characteristics depending on the alignment state of the liquid crystal compound, and includes a VA (vertical alignment) mode, an IPS (in-plane switching) mode, an OCB (optically compensated bend) mode, and a TN (twisted). nematic) mode, STN (super twisted nematic) mode, and the like. Among them, it is suitable as a retardation film for an IPS mode liquid crystal display device.
In addition, this optically anisotropic film converts linearly polarized light as seen from the oblique angle on the light exit side into circularly polarized light or elliptically polarized light, converts circularly polarized light or elliptically polarized light into linearly polarized light, It can also be used as a retardation film used to change the polarization direction.

In the refractive index ellipsoid formed by the optical anisotropic film, the refractive index ellipsoid formed by the optical anisotropic film is nx in the refractive index ellipsoid formed by the optical anisotropic film. In the refractive index ellipsoid formed by the optically anisotropic film, the refractive index in the direction parallel to the film plane and perpendicular to the nx direction is ny, and the direction perpendicular to the film plane When the refractive index is nz, it can be classified as follows. This optically anisotropic film is preferably, positive C plate having an optical characteristic represented by _{n x ≒ n y <n z} .
positive A plate of _{n x> n y ≒ n z} ,
negative C plate of _{n x ≒ n y> n z} ,
positive C plate of _{n x ≒ n y <n z} ,
positive O plate and the negative O plate of n _x ≠ n _y ≠ n _z

  When this optically anisotropic film is used as a positive C plate, the front retardation value Re (550) for light of 550 nm is usually in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm, and in the thickness direction. The retardation value Rth is usually in the range of −10 nm to −300 nm, and preferably in the range of −20 nm to −200 nm.

The retardation value Rth in the thickness direction, which means the refractive index anisotropy in the thickness direction of the optically anisotropic film, is a retardation value R ₅₀ measured by inclining 50 degrees with the in-plane fast axis as the tilt axis. It can be calculated from the in-plane retardation value _R0 . That is, the retardation value Rth in the thickness direction is the in-plane retardation value R ₀ , the retardation value R ₅₀ measured by tilting the fast axis as the tilt axis by 50 degrees, the thickness d of the film, and the average refraction of the film From the rate n ₀ , nx, ny, and nz can be obtained by the following equations (9) to (11), and can be calculated by substituting these into equation (8).

Rth = [(nx + ny) / 2−nz] × d (8)
R ₀ = (nx−ny) × d (9)
R ₅₀ = (nx−ny ′) × d / cos (φ) (10)
(nx + ny + nz) / 3 = n ₀ (11)
here,
φ = sin ⁻¹ [sin (40 °) / n ₀ ]
ny ′ = ny × nz / [ny ² × sin ² (φ) + nz ² × cos ² (φ)] ^1/2

This optically anisotropic film is also useful as a member constituting a polarizing plate. The polarizing plate of the present invention includes at least one optically anisotropic film, and may be included as a retardation film.
As a specific example of a polarizing plate, the polarizing plate shown by FIG. 1 (a)-FIG.1 (e) is mentioned. A polarizing plate 4a shown in FIG. 1 (a) is a polarizing plate in which a retardation film 1 and a polarizing film 2 are directly laminated, and a polarizing plate 4b shown in FIG. 1 (b) is a retardation film. 1 and the polarizing film 2 are the polarizing plates bonded together through adhesive layer 3 '. A polarizing plate 4c shown in FIG. 1 (c) is a polarizing plate in which a retardation film 1 and a retardation film 1 ′ are laminated, and further, a retardation film 1 ′ and a polarizing film 2 are laminated. A polarizing plate 4d shown in FIG. 1 (d) is obtained by laminating a retardation film 1 and a retardation film 1 ′ via an adhesive layer 3, and further laminating a polarizing film 2 on the retardation film 1 ′. It is the made polarizing plate. A polarizing plate 4e shown in FIG. 1 (e) is obtained by bonding a retardation film 1 and a retardation film 1 ′ through an adhesive layer 3, and further bonding the retardation film 1 ′ and the polarizing film 2 together. It is a polarizing plate bonded through an agent layer 3 ′. “Adhesive” means a general term for an adhesive and / or an adhesive. The optically anisotropic film is included in at least one selected from the group consisting of the retardation film 1 and the retardation film 1 ′.

  The polarizing film 2 may be a film having a polarizing function. Examples of the film include a stretched film on which a dye having absorption anisotropy is adsorbed and a film coated with a dye having absorption anisotropy. Examples of the dye having absorption anisotropy include dichroic dyes such as iodine and azo compounds.

  As a stretched film on which a dye having absorption anisotropy is adsorbed, a film obtained by adsorbing a dichroic dye on a polyvinyl alcohol film and a film obtained by adsorbing a dichroic dye by stretching the polyvinyl alcohol film A film etc. are mentioned.

  Examples of the film coated with a dye having absorption anisotropy include a film containing a dichroic dye having liquid crystallinity or a film obtained by applying a composition containing a dichroic dye and a liquid crystal compound. It is done.

  The film having a polarizing function preferably has a protective film on one side or both sides thereof. Examples of the protective film include the same ones as described above.

Specific examples of the stretched film on which the dye having absorption anisotropy is adsorbed include the polarizing plates described in Japanese Patent No. 3708062, Japanese Patent No. 4432487, and the like.
Specific examples of the film coated with the pigment having absorption anisotropy include polarizing films described in JP 2012-33249 A and the like.

  The thickness of the polarizing film 2 is preferably thin, but if it is too thin, the strength is lowered and the processability tends to be inferior. The thickness of the polarizing film is usually 0.1 μm to 300 μm, preferably 1 μm to 200 μm, and more preferably 5 μm to 100 μm.

  The adhesive forming the adhesive layer 3 and the adhesive layer 3 ′ is preferably an adhesive having high transparency and excellent heat resistance. Examples of such adhesives include acrylic adhesives, epoxy adhesives, and urethane adhesives.

  The optically anisotropic film can be used for a display device. The display device includes a liquid crystal display device including a liquid crystal panel in which an optically anisotropic film and a liquid crystal panel are bonded together, and organic electroluminescence (hereinafter referred to as “EL” in which an optically anisotropic film and a light emitting layer are bonded together. And an organic EL display device including a panel. A liquid crystal display device will be described as an embodiment of a display device provided with the optically anisotropic film of the present invention.

  Examples of the liquid crystal display device include liquid crystal display devices 10a and 10b shown in FIGS. 2 (a) and 2 (b). In the liquid crystal display device 10 a shown in FIG. 2A, the polarizing plate 4 and the liquid crystal panel 6 of the present invention are bonded together via an adhesive layer 5. In the liquid crystal display device 10b shown in FIG. 2B, the polarizing plate 4 of the present invention is on one surface of the liquid crystal panel 6, the polarizing plate 4 'of the present invention is on the other surface of the liquid crystal panel 6, and the adhesive layer 5 and It has a structure in which the adhesive layers 5 'are bonded to each other. In these liquid crystal display devices, by applying a voltage to the liquid crystal panel using an electrode (not shown), the alignment of the liquid crystal molecules is changed, and black and white display can be realized.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “%” and “part” mean mass% and part by mass unless otherwise specified.

[Preparation of Oriented Polymer Composition]
The composition of the orientation polymer composition is shown in Table 1. N-methyl-2-pyrrolidone, 2-butoxyethanol and ethylcyclohexane were added to Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is a commercially available oriented polymer, to obtain an oriented polymer composition (1).

表１の値は、調製した組成物の全量に対する各成分の含有割合を表す。ＳＥ−６１０については、固形分量を納品仕様書に記載の濃度から換算した。

The value of Table 1 represents the content rate of each component with respect to the whole quantity of the prepared composition. For SE-610, the solid content was converted from the concentration described in the delivery specification.

[Preparation of optical anisotropic film forming composition]
Table 2 shows the composition of the composition for forming an optically anisotropic film. After mixing each component and stirring the obtained solution at 80 degreeC for 1 hour, it cooled to room temperature and obtained the composition (1) for optically anisotropic film formation.

表２における括弧内の値は、調製した組成物の全量に対する各成分の含有割合を表す。
表２におけるＬＲ９０００はＢＡＳＦジャパン社製のＬａｒｏｍｅｒ（登録商標）ＬＲ−９０００を、Ｉｒｇ９０７はＢＡＳＦジャパン社製のイルガキュア９０７を、ＢＹＫ３６１Ｎはビックケミージャパン製のレベリング剤を、ＬＣ２４２は、下記式で示されるＢＡＳＦ社製の液晶化合物を、ＰＧＭＥＡは、プロピレングリコール１−モノメチルエーテル２−アセタートを表す。

The values in parentheses in Table 2 represent the content ratio of each component with respect to the total amount of the prepared composition.
In Table 2, LR9000 is a BASF Japan-made Laromer (registered trademark) LR-9000, Irg907 is a BASF Japan-made Irgacure 907, BYK361N is a leveling agent made by BYK Japan, and LC242 is represented by the following formula. In the liquid crystal compound manufactured by BASF, PGMEA represents propylene glycol 1-monomethyl ether 2-acetate.

Example 1
Using an atmospheric pressure plasma surface treatment apparatus (roll direct head type AP-T04S-R890, manufactured by Sekisui Chemical Co., Ltd.), an atmosphere containing nitrogen and oxygen (volume ratio nitrogen: oxygen = 99.9: 0.1) Below, plasma is generated under the condition of 1.3 kV, and the cycloolefin polymer film is transported at a transport speed of 4 m / min on the surface of a roll-shaped cycloolefin polymer film (ZF-14, manufactured by Nippon Zeon Co., Ltd.). Then, 100 m was processed. The orientation polymer composition (1) was applied to the surface of the cycloolefin polymer film subjected to the plasma treatment using a die coater, conveyed to a drying furnace at 90 ° C., and dried for 1 minute to form an orientation film. Subsequently, the optically anisotropic film forming composition (1) was applied to the surface of the obtained alignment film using a die coater, and applied using an electric far infrared heater (manufactured by Noritake Company Limited). In addition, the distance between the composition for optically anisotropic film formation (1) and the far-infrared source of the electric far-infrared heater was maintained at 10 cm, and infrared rays (set temperature: 80 ° C.) were irradiated for 30 seconds. Then, it is dried for 1 minute in a blast drying oven (wind speed: 2 m / sec) at 90 ° C., and irradiated with ultraviolet rays at a wavelength of 365 nm with an illuminance of 120 W / cm using a high-pressure mercury lamp (manufactured by Ushio Inc.). The liquid crystal compound was polymerized to obtain a roll-shaped optically anisotropic film (1) provided with the optically anisotropic film (1).

Comparative Example 1
Using an atmospheric pressure plasma surface treatment apparatus (roll direct head type AP-T04S-R890, manufactured by Sekisui Chemical Co., Ltd.), an atmosphere containing nitrogen and oxygen (volume ratio nitrogen: oxygen = 99.9: 0.1) Below, plasma is generated under the condition of 1.3 kV, and the cycloolefin polymer film is transported at a transport speed of 4 m / min on the surface of a roll-shaped cycloolefin polymer film (ZF-14, manufactured by Nippon Zeon Co., Ltd.). Then, 100 m was processed. The orientation polymer composition (1) was applied to the surface of the cycloolefin polymer film subjected to the plasma treatment using a die coater, conveyed to a drying furnace at 90 ° C., and dried for 1 minute to form an orientation film. Subsequently, the optically anisotropic film-forming composition (1) was applied to the surface of the obtained alignment film using a die coater, and 1 minute 30 in a 90 ° C. blown drying oven (wind speed: 2 m / sec). The liquid crystal compound is polymerized by drying with a high pressure mercury lamp (manufactured by Ushio Electric Co., Ltd.) and irradiating with ultraviolet rays at an illuminance of 120 W / cm at a wavelength of 365 nm. A roll-shaped optically anisotropic film (2) was obtained.

[Measurement of optical properties]
The retardation value of the optically anisotropic films (1) and (2) was measured with a measuring machine (KOBRA-WR, manufactured by Oji Scientific Instruments). Measurement was performed by changing the incident angle of light to the sample, and the alignment state of the liquid crystal compound was confirmed. The results are shown in Table 3.

[Transparency evaluation]
Using a haze meter (model HZ-2) manufactured by Suga Test Instruments Co., Ltd., the haze values of the optically anisotropic films (1) and (2) were measured by the double beam method. The results are shown in Table 3.

[Measurement of film thickness distribution]
The film thickness distributions of the optically anisotropic films (1) and (2) were measured using an ellipsometer M-220 manufactured by JASCO Corporation. The results are shown in Table 3.

  The present invention is useful as a method for producing an optically anisotropic film having a low film thickness distribution.

1, 1 ': retardation film 2, 2': polarizing film 3, 3 ': adhesive layers 4a, 4b, 4c, 4d, 4e, 4, 4': polarizing plate 5, 5 ': adhesive layer 6: liquid crystal Panel 10a, 10b: Liquid crystal display device

Claims (10)

A polymer of vertically aligned liquid crystal compounds,
_{n x} = n y <n _z
Wherein, n _x is a main refractive index in the direction parallel to the film plane, n _y is a refractive index in a direction perpendicular to the n _y there parallel to the film plane, n _z is film Refractive indexes in the direction perpendicular to the plane are shown. ]
A method for producing an optically anisotropic film having optical characteristics represented by:
A method for producing an optically anisotropic film, wherein the steps (1) to (3) are performed in this order.
(1) Step of applying a composition for forming an optically anisotropic film containing a liquid crystal compound and a solvent to a substrate (2) First, the composition for forming an optical anisotropy applied to a substrate is irradiated with infrared rays by blowing hot air to step (3) optically anisotropic film forming composition after being irradiated with infrared rays, the process of the optically anisotropic film forming composition was heated to 60 to 200 ° C. drying The liquid crystal compound has the formula (X)
  P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -(X)
[In formula (X), P ¹¹ Represents a hydrogen atom or a polymerizable group.
  A ¹¹ Represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and divalent aromatic hydrocarbon group is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group. The hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.
  B ¹¹ Are —O—, —S—, —CO—O—, —O—CO—, —O—CO—O—, —CO—NR. ¹⁶ -, -NR ¹⁶ -CO-, -CO-, -CS- or a single bond is represented. R ¹⁶ Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
  B ¹² And B ¹³ Each independently represents —C≡C—, —CH═CH—, —CH ₂ -CH ₂ -, -O-, -S-, -C (= O)-, -C (= O) -O-, -O-C (= O)-, -O-C (= O) -O-, -CH = N-, -N = CH-, -N = N-, -C (= O) -NR. ¹⁶ -, -NR ¹⁶ -C (= O)-, -OCH ₂ -, -OCF ₂ -, -CH ₂ O-, -CF ₂ O—, —CH═CH—C (═O) —O—, —O—C (═O) —CH═CH— or a single bond is represented.
  E ¹¹ Represents an alkanediyl group having 1 to 12 carbon atoms, a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and the hydrogen atom contained in the alkoxy group is May be substituted with a halogen atom. In addition, —CH constituting the alkanediyl group ₂ -May be replaced by -O- or -CO-. ]
The manufacturing method of Claim 1 which is a compound shown by these. Infrared is irradiated by the infrared irradiation unit having an infrared source, manufacturing method of the optically anisotropic film according to claim 1 or claim 2 temperature Ru der 120 ° C. or less of the infrared source. The method for producing an optically anisotropic film according to claim 3 , wherein the distance from the infrared ray source of the infrared irradiator to the composition for forming optical anisotropy applied to the substrate is from 1 cm to 100 cm. The method for producing an optically anisotropic film according to any one of claims 1 to 4, wherein the irradiation time of infrared rays is 5 seconds to 5 minutes . The method for producing an optically anisotropic film according to any one of claims 1 to 5 , wherein the drying is performed in an atmosphere having a wind speed of 1 m / second to 10 m / second and a temperature of 60 to 200 ° C. The method for producing an optically anisotropic film according to any one of claims 1 to 6 , wherein the vapor pressure of the solvent contained in the composition for forming an optically anisotropic film is 0.01 kPa to 0.6 kPa. The method for producing an optically anisotropic film according to any one of claims 1 to 7 , wherein the substrate is a long film roll having a length in the longitudinal direction of 100 m or more. Method for producing an optical anisotropic film according to any one of claims 1 to 8 for step (1) to (3) in succession. The method for producing an optically anisotropic film according to claim 9 , wherein the substrate is conveyed while being conveyed at a speed of 3 m / min to 20 m / min.

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