WO2014157251A1 - Optical film, polarizing plate, image display device, and optical film fabrication method - Google Patents

Optical film, polarizing plate, image display device, and optical film fabrication method Download PDF

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Publication number
WO2014157251A1
WO2014157251A1 PCT/JP2014/058364 JP2014058364W WO2014157251A1 WO 2014157251 A1 WO2014157251 A1 WO 2014157251A1 JP 2014058364 W JP2014058364 W JP 2014058364W WO 2014157251 A1 WO2014157251 A1 WO 2014157251A1
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liquid crystal
film
hard coat
layer
crystal layer
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PCT/JP2014/058364
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French (fr)
Japanese (ja)
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鈴木　宏明
松本　卓也
さなみ 矢崎
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Ｊｘ日鉱日石エネルギー株式会社
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Publication of WO2014157251A1 publication Critical patent/WO2014157251A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3016—Polarising elements involving passive liquid crystal elements
    • G02B1/105—
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/14—Protective coatings, e.g. hard coatings

Definitions

  • the present invention relates to an optical film, a polarizing plate, an image display device, and a method for manufacturing an optical film.
  • polarizing plates, antireflection plates, retardation plates and the like have been used in the field of image display devices and the like from the viewpoint of improving the viewing angle and improving image quality.
  • an optical film having a liquid crystal layer having optical properties such as birefringence optical anisotropy
  • an optical film including such a liquid crystal layer has a problem that when a foreign object comes into contact with the surface of the liquid crystal layer, the optical film is easily scratched and optical characteristics such as birefringence change. Therefore, in such an optical film, a hard coat layer (overcoat layer) can be formed on the liquid crystal layer in order to prevent the liquid crystal layer from being scratched and the performance such as birefringence from changing. Proposed.
  • Patent Document 1 discloses an optical film in which a birefringent layer is formed on a transparent substrate, and a hard coat layer is further formed on the birefringent layer. It is disclosed that such a birefringent layer may be a layer formed by applying and drying a solution containing a liquid crystalline polymer (for example, a lyotropic liquid crystalline polymer).
  • a liquid crystalline polymer for example, a lyotropic liquid crystalline polymer
  • Patent Document 1 there is no description of using a hard coat layer from the viewpoint of suppressing the property of the birefringent layer made of a liquid crystalline polymer from being changed by heat, and Also, there is no specific disclosure about providing an optical film with a liquid crystal layer in which the alignment state of the liquid crystalline polymer is fixed in a specific state.
  • the adhesion between the homeotropic alignment liquid crystal layer and the hard coat layer can be made sufficiently high, and it has a sufficiently high scratch resistance and a sufficiently excellent heat resistance. And it aims at providing the optical film which can fully suppress that the orientation state of the said liquid-crystal layer changes with a heat
  • a conventional hard coat material as described in Patent Document 1 described above is a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state (hereinafter simply referred to as a case in some cases). It was found that this is not necessarily sufficient in terms of laminating a hard coat layer with a sufficiently high adhesion to “homeotropic alignment liquid crystal layer”.
  • the present inventors may laminate hard coat layers made of the same hard coat material on liquid crystal layers having different alignment states (liquid crystal layers such as homeotropic alignment, homogeneous alignment, and spray alignment), respectively.
  • a liquid crystal layer in which a hard coat layer having a sufficiently high adhesion to a liquid crystal layer in which a specific alignment is fixed and a different alignment is fixed in a liquid crystal layer in which the adhesion of the hard coat layer varies depending on the alignment state of the liquid crystal layer It has also been found that even if it is applied as it is, a sufficiently high adhesion cannot always be obtained.
  • the liquid crystal layer fixed in the homeotropic alignment state has a tendency to greatly decrease its performance, particularly due to the alignment distortion caused by heat, as compared with the liquid crystal layer fixed in other alignment states.
  • the hard coat layer made of a conventional hard coat material as described in Patent Document 1 does not necessarily have sufficient heat resistance to a liquid crystal layer having homeotropic alignment. It was also found that the deterioration of the quality of the optical film due to heat cannot be sufficiently suppressed.
  • a base material a liquid crystal layer laminated on the base material, and the liquid crystal layer
  • An optical film comprising a hard coat layer laminated thereon, wherein the liquid crystal layer is a layer in which a liquid crystal material is fixed in a homeotropic alignment state, and the hard coat layer includes a urethane (meth) acrylate resin
  • the hard coat layer includes a urethane (meth) acrylate resin
  • the optical film of the present invention is an optical film comprising a base material, a liquid crystal layer laminated on the base material, and a hard coat layer laminated on the liquid crystal layer,
  • the liquid crystal layer is a layer in which a liquid crystal material is fixed in a homeotropic alignment state
  • the hard coat layer is a layer formed by curing a hard coat material containing a urethane (meth) acrylate resin. is there.
  • the hard coat layer preferably has a thickness of 0.1 to 5 ⁇ m.
  • the liquid crystal material preferably contains a poly (meth) acrylate liquid crystal polymer.
  • the substrate is made of a cyclic olefin polymer.
  • the polarizing plate of the present invention comprises the optical film of the present invention. Moreover, the image display apparatus of this invention is equipped with the polarizing plate of the said invention.
  • a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state is laminated on a base material, and then a hard material containing a urethane (meth) acrylate resin on the liquid crystal layer.
  • a hard coat layer is laminated by applying and curing a coating material, It is a method of obtaining an optical film provided with the substrate, the liquid crystal layer laminated on the substrate, and the hard coat layer formed by curing the hard coat material laminated on the liquid crystal layer. .
  • the adhesion between the homeotropic alignment liquid crystal layer and the hard coat layer can be made sufficiently high, has sufficiently high scratch resistance, and sufficiently excellent heat resistance. It is possible to provide an optical film that can sufficiently suppress the change in the alignment state of the liquid crystal layer due to heat and a method for producing the same.
  • Example 5 is a graph showing the relationship between the heating time (test time) and the thickness direction retardation (Rth) change rate for the optical films obtained in Example 1 and Comparative Examples 1 and 2.
  • the optical film of the present invention is an optical film comprising a base material, a liquid crystal layer laminated on the base material, and a hard coat layer laminated on the liquid crystal layer,
  • the liquid crystal layer is a layer in which a liquid crystal material is fixed in a homeotropic alignment state
  • the hard coat layer is a layer formed by curing a hard coat material containing a urethane (meth) acrylate resin. is there.
  • the base material used in the present invention is not particularly limited as long as it can be used for an optical film, and a known base material for an optical film can be appropriately used.
  • Examples of such a base material include a base material made of an organic polymer material and a base material made of an inorganic material (for example, a glass plate, a metal plate, a film formed from a metal such as aluminum). .
  • a substrate made of an organic polymer material from the viewpoint of cost and continuous productivity.
  • organic polymer materials include polyvinyl alcohol, polyimide, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyether ketone, polyether ether ketone, polyarylate, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; Cellulose polymers such as cellulose and triacetyl cellulose; polycarbonate polymers; transparent polymers such as acrylic polymers such as polymethyl (meth) acrylate; styrene polymers such as polystyrene and acrylonitrile / styrene copolymers; polyethylene, polypropylene, ethylene Olefin polymers such as propylene copolymer; Cyclic olefin polymer (polycycloolefin); Vinyl chloride Polymers; nylon and aromatic amide polymers such as polyamide; polymeric
  • “methacryl” and “acryl” are sometimes collectively referred to as “(meth) acryl” in some cases. In some cases, “methacrylate” and “acrylate” are collectively referred to as “(meth) acrylate”.
  • an organic polymer material it is possible to exhibit characteristics (for example, transparency) suitable for an optical film. Therefore, triacetyl cellulose, polycarbonate, cyclic olefin polymer (cycloolefin polymer: COP) ) Is more preferable, and a cyclic olefin polymer is particularly preferable.
  • cyclolefin polymer cycloolefin polymer: COP
  • a base material made of such an organic polymer material a film made of triacetyl cellulose, polycarbonate, a cyclic olefin polymer (cycloolefin polymer: COP) is highly transparent and easily available.
  • a base material plastic film
  • the liquid crystal material contains a poly (meth) acrylate-based liquid crystal polymer, a sufficiently high adhesion can be imparted, so A film made of an olefin polymer (hereinafter sometimes referred to as “COP film”) is particularly preferred.
  • cyclic olefin polymer is a general generic name for resins obtained from cyclic olefins such as norbornene, dicyclopentadiene, tetracyclododecene and derivatives thereof.
  • a cyclic olefin polymer include a cyclic olefin ring-opening polymer, a cyclic olefin addition polymer, a random copolymer of a cyclic olefin and an ⁇ -olefin such as ethylene and propylene, and the like. Examples include graft-modified products modified with saturated carboxylic acid and derivatives thereof, and hydrides thereof.
  • a cyclic olefin, norbornene, its derivative (s), and dicyclopentadiene are preferable.
  • Such a substrate is not particularly limited, but preferably has a retardation function, and more preferably a COP film having a retardation function.
  • a substrate particularly preferably a COP film
  • Such a substrate may be a uniaxially stretched film (so-called uniaxially stretched film) or a biaxially stretched film (so-called biaxially stretched film).
  • a method of uniaxial stretching performed when obtaining such a uniaxially stretched film longitudinal uniaxial stretching using a difference in peripheral speed between two or more rolls, or both of the base material (particularly preferably COP film) are used. It is preferable to employ tenter stretching that grips the side and stretches in the width direction.
  • such a base material is good also as a film which develops biaxial optical anisotropy by extending this to the vertical direction and a horizontal direction, and has optical anisotropy.
  • a substrate that has been subjected to a Z-axis alignment treatment may be used as such a base material.
  • such a substrate may be appropriately subjected to surface treatment such as corona treatment, plasma treatment, UV-ozone treatment, saponification treatment, etc. on one or both sides for the purpose of controlling the adhesion.
  • an in-plane retardation value (in the case of a film, in the film surface) (hereinafter, the in-plane retardation value of such a substrate is sometimes abbreviated as “Re1”.
  • Re1 (nx ⁇ ny) ⁇ d1 [nm] (A)
  • the in-plane retardation value (Re1) of such a substrate is also optimal depending on the application difference when used as a viewing angle improving film of an image display device (for example, a liquid crystal display device).
  • the optimum values differ depending on the method of the image display device (for example, a liquid crystal display device) and various optical parameters even when used in a viewing angle improving film.
  • the range is preferably from 30 nm to 500 nm, and more preferably from 50 nm to 400 nm.
  • the retardation value in the thickness direction of such a substrate is sometimes abbreviated as “Rth1”).
  • Rth1 ⁇ (nx + ny) / 2 ⁇ nz ⁇ ⁇ d1 [nm]
  • Rth1 ⁇ (nx + ny) / 2 ⁇ nz ⁇ ⁇ d1 [nm]
  • Re1 and Rth1 are set to values within the above range.
  • an image display device eg, a liquid crystal display device
  • the field of view is corrected while correcting the color tone of the image display.
  • the corners can be widened, and when used as a brightness enhancement film for an image display device, a good brightness enhancement effect can be obtained.
  • the Re1 value of the substrate is smaller than 30 nm or larger than 500 nm, a sufficient viewing angle improving effect cannot be obtained, or unnecessary coloring tends to occur when viewed obliquely.
  • Rth1 of the substrate is smaller than 0 nm or larger than 300 nm, a sufficient viewing angle improving effect cannot be obtained or unnecessary coloring tends to occur when viewed from an oblique direction.
  • a commercially available product may be appropriately used as such a base material.
  • a COP film is used as the base material
  • ZEONEX manufactured by ZEON CORPORATION, ZEONOR manufactured by ZEON CORPORATION, manufactured by JSR Corporation Arton, Sessui Chemical Co., Ltd. Essina, Topas Advanced Polymers GmbH Topas, Mitsui Chemicals Co., Ltd. Appell, etc. can be used as appropriate.
  • a base material in which an alignment film is formed on the surface may be used in order to stably bring the liquid crystal material into a homeotropic alignment state.
  • a material for forming such an alignment film (alignment film forming material)
  • a known material can be appropriately used.
  • polyvinyl alcohol (PVA) polyvinyl cinnamate, polyvinyl ether, polyimide, Examples include fluorinated polyimide.
  • Such an alignment film is not particularly limited, and a known method can be appropriately employed.
  • a method that can be suitably employed as the alignment film forming step will be briefly described.
  • a solution in which the alignment film forming material is dissolved in a solvent is prepared, and the solution is used as a film for a substrate.
  • Etc. for example, what was demonstrated as a base material like the above-mentioned COP film etc.
  • Such a solution may be appropriately prepared using a solvent capable of dissolving the alignment film forming material.
  • the solvent is not particularly limited as long as it is a solvent capable of dissolving PVA.
  • a solvent capable of dissolving PVA for example, water; lower alcohols such as methanol, ethanol, isopropyl alcohol; mixtures thereof can be used as appropriate.
  • various additives that can be used for the alignment film are appropriately selected within a range that does not affect the coating process and the alignment of the liquid crystal material. May be used.
  • heating may be appropriately performed to promote dissolution.
  • the method for applying the solution is not particularly limited, and a known method can be used as appropriate.
  • a coating method employing a dispenser method, a gravure coating method, a micro gravure method, a screen printing method, a lip coating method, a die coating method, or the like can be used as appropriate.
  • a coating method employing a gravure coating method, a lip coating method, or a die coating method is particularly preferable.
  • the coating film (alignment film) obtained by coating may be dried as necessary.
  • the drying temperature in such a drying step varies depending on the type of the alignment film forming material, and basically, from the viewpoint of the heat resistance (softening point or glass transition point) of the material itself, although it is desirable that the temperature be lower than the softening point or glass transition point of the material itself, depending on the purpose, the temperature may be higher than the softening point or glass transition point.
  • the drying temperature is preferably 50 ° C. to 180 ° C., and more preferably 80 ° C. to 160 ° C., for example.
  • the drying time is not particularly limited, but is preferably 10 seconds to 60 minutes, more preferably 1 minute to 30 minutes. Further, when using a drying apparatus for such drying, it is preferable to control the relative moving speed of the film to be dried and the drying apparatus so that the relative wind speed is 60 m / min to 1200 m / min. .
  • the homeotropic alignment is basically an alignment structure in which in-plane anisotropy does not occur, and thus the rubbing process is not necessarily a necessary process. Therefore, in the optical film of the present invention in which the liquid crystal layer laminated on the substrate is a layer (homeotropic alignment liquid crystal layer) in which a liquid crystal material is fixed in a homeotropic alignment state, the substrate is rubbed. It is not always necessary to apply it.
  • the substrate it is preferable to subject the substrate to a weak rubbing treatment. Further, as such a weak rubbing treatment, the base material is moved so that the base material comes into contact with the roll while the rubbing cloth is wound around the roll, and the surface of the base material is rubbed with the rubbing cloth. It is preferable to adopt the method.
  • the ratio of the cloth movement speed (rotational speed) to the substrate movement speed (circumferential speed ratio) is preferably 50 or less, more preferably 25 or less. More preferably, it is 10 or less.
  • the peripheral speed ratio is greater than 50, the rubbing effect is too strong, and the liquid crystal material cannot be perfectly aligned vertically, and tends to be inclined in the in-plane direction from the vertical direction.
  • a liquid crystal layer is laminated on the substrate.
  • a liquid crystal layer is a layer (homeotropic alignment liquid crystal layer) in which a liquid crystal material is fixed in a homeotropic alignment state.
  • the liquid crystal material that is a material for such a liquid crystal layer is not particularly limited as long as it is a material containing a liquid crystalline compound that can be homeotropically aligned on the substrate to fix the alignment state.
  • a liquid crystal compound for example, a low molecular liquid crystal compound (a liquid crystal monomer having a polymerizable group), a liquid crystal polymer compound, or a mixture thereof can be appropriately used.
  • a polymerizable group that reacts with light or heat is used from the viewpoint that alignment can be easily fixed.
  • the compound provided is preferred.
  • a polymerizable group a vinyl group, acryloyl group, vinyloxy group, oxiranyl group, oxetanyl group, aziridinyl group and the like are preferable.
  • other polymerizable groups such as an isocyanate group, a hydroxyl group, an amino group, an acid anhydride group, and a carboxyl group may be used depending on the reaction conditions.
  • main chain liquid crystalline polymers include polyester liquid crystal polymers, polyester amide liquid crystal polymers, polyamide liquid crystal polymers, polyamide imide liquid crystal polymers, and polycarbonate liquid crystal polymers.
  • side chain liquid crystal polymer include poly (meth) acrylate liquid crystal polymer, polymalonate liquid crystal polymer, polyether liquid crystal polymer, and polysiloxane liquid crystal polymer.
  • the side chain liquid crystalline polymer is more preferable from the viewpoint that it is desirable to have good alignment even under low temperature alignment conditions, and a poly (meth) acrylate liquid crystal polymer is more preferable. More preferred. Further, such a poly (meth) acrylate-based liquid crystal polymer not only has a chemical structure exhibiting liquid crystallinity, but also desirably has a polymerization group in order to more efficiently fix the aligned liquid crystal structure. Therefore, a poly (meth) acrylate liquid crystal polymer represented by the following general formula (1) (respectively repeating units shown in the following general formula (1) should satisfy the conditions of the molar ratio represented by a to f described later. (Poly (meth) acrylate-based liquid crystal polymer) contained in the form of
  • each R 1 independently represents hydrogen or a methyl group
  • each R 2 independently represents hydrogen, a methyl group, an ethyl group, a butyl group, a hexyl group, an octyl group
  • each R 3 independently represents hydrogen, a methyl group or an ethyl group
  • R 4 represents a hydrocarbon group having 1 to 24 carbon atoms
  • L 1 represents Independently, it represents a single bond, —O—, —O—CO—, —CO—O—,
  • the molar ratios represented by a to f are preferably values within the numerical ranges of a to f shown below.
  • R 2 is preferably hydrogen, methyl group, butyl group, methoxy group, cyano group, bromo group, or fluoro group, and particularly preferably hydrogen, methoxy group, or cyano group.
  • L 1 is preferably a single bond, —O—, —O—CO— or —CO—O—.
  • R 4 is preferably a hydrocarbon group having 2, 3, 4 , 6, 8 or 18 carbon atoms.
  • the poly (meth) acrylate-based liquid crystal polymer represented by the general formula (1) includes a repeating unit other than the repeating unit in the general formula (1) as long as the effect is not impaired.
  • the molar ratio of the content of other repeating units to the total amount of repeating units in the general formula (1) ([total amount of repeating units in the general formula (1)]: [others]
  • the content of the repeating unit] is preferably 99: 1 to 80:20, more preferably 95: 5 to 85:15.
  • the side chain type liquid crystalline polymer suitable as such a liquid crystalline compound preferably has a weight average molecular weight of 1,000 to 200,000, particularly preferably 3,000 to 50,000.
  • a weight average molecular weight becomes a value outside the above range, the strength of the liquid crystal layer tends to be insufficient or the orientation tends to decrease.
  • Tosoh's high-speed GPC device EcoSec HLC-8320GPC is used as a measuring device, TSKgelSuperH4000, TSKgelSuperH1000, TSKgelSuperMP (HZ) -H, TSKgelMultiporeHZ-H are used as measuring conditions, and column.
  • a value obtained as a weight average molecular weight in terms of polystyrene is adopted.
  • 1 type may be used independently, or 2 or more types may be mixed and utilized.
  • such a liquid crystalline compound includes a cationic polymerizable group from the viewpoint of further improving the heat resistance of the obtained liquid crystal layer when it is polymerized using a cationic polymerizable group during immobilization. More preferably, it contains As such a cationically polymerizable group, an epoxy group, an oxetanyl group, and a vinyloxy group are preferable, and an oxetanyl group is more preferable.
  • the poly (meth) acrylate liquid crystal polymer represented by the general formula (1) can be suitably used.
  • the synthesis method of such a liquid crystalline compound is not particularly limited, and can be appropriately synthesized by applying a known method (for example, a method used in a general organic chemistry synthesis method).
  • the poly (meth) acrylate-based liquid crystal polymer represented by the general formula (1) is a (meth) acrylic compound (for example, in the formula (1) that can form a repeating unit in the formula (1).
  • the conditions for such polymerization are not particularly limited, and known conditions can be appropriately employed.
  • a commercially available product may be appropriately used.
  • liquid crystal material only the liquid crystal compound may be used, but from the viewpoint that adhesion with a substrate can be further improved, a (meth) acryl having an oxetane group together with the liquid crystal compound. It is preferable to use a compound containing a compound (using the liquid crystal material as a liquid crystalline composition containing a (meth) acrylic compound having an oxetane group together with the liquid crystalline compound). As described above, when the liquid crystal material contains a (meth) acrylic compound having an oxetane group, such a base material is used even when a base material (for example, a COP film) made of a hardly adhesive material is used as the base material.
  • a base material for example, a COP film
  • a sufficiently high adhesive force is obtained between the liquid crystal layer and the liquid crystal layer, and the adhesiveness between the substrate and the liquid crystal layer tends to be greatly improved. That is, when the (meth) acrylic compound having an oxetane group is contained in the liquid crystal material, a substrate (for example, a COP film) and a liquid crystal layer made of a hardly-adhesive material are compared with the case where it is not contained. Between the two, there is a tendency that more sufficient adhesion can be imparted.
  • the reason why the adhesion between the substrate and the liquid crystal layer is improved by the (meth) acrylic compound having the oxetane group is not necessarily clear, but the (meth) acrylic compound having the oxetane group is difficult to adhere to.
  • the present inventors infer that this is because some kind of mediating action is obtained in the adhesion between the substrate (for example, a COP film) made of the liquid crystal and the liquid crystal compound having insufficient affinity for the substrate.
  • a compound exhibiting liquid crystallinity is used alone as the liquid crystal compound in the liquid crystal material (no other liquid crystal compound is used).
  • the liquid crystalline compound means a liquid crystalline compound other than the (meth) acrylic compound having the oxetane group.
  • the (meth) acrylic compound having such an oxetane group at least one of the compounds represented by the following general formulas (2) to (4) is preferable.
  • each R 5 independently represents hydrogen or a methyl group
  • each R 6 independently represents hydrogen, a methyl group or an ethyl group
  • each of L 2 represents Independently represents a single bond, —O—, —O—CO— or —CO—O—, wherein m is each independently an integer from 1 to 10, and n is each independently 0 to 10 It is an integer up to.
  • L 2 is a single bond” means that a group bonded via L 2 is directly bonded. For example, when it is assumed that there is a compound represented by the formula: AL 2 —B L 2 is a single bond means that the compound is a compound represented by the formula AB.
  • Such a (meth) acrylic compound having an oxetane group is not necessarily required to exhibit liquid crystallinity.
  • the (meth) acrylic compound having an oxetane group one of the compounds represented by the above general formulas (2) to (4) may be used alone, or the above general formulas (2) to (4) may be used. Or a mixture of two or more of the compounds represented by formula (1).
  • the compounds represented by the general formulas (2) to (4) are not particularly limited, but preferred examples thereof include the following compounds.
  • the method for synthesizing such a (meth) acrylic compound having an oxetane group is not particularly limited, and is appropriately synthesized by applying a known method (for example, a method used in ordinary organic chemistry synthesis methods). can do.
  • a known method for example, a method used in ordinary organic chemistry synthesis methods.
  • the oxetane group and the (meth) acrylic group A (meth) acrylic compound having an oxetane group having two completely different reactive groups can be synthesized.
  • the oxetane group since the oxetane group has cationic polymerizability, it is necessary to select reaction conditions in consideration of causing side reactions such as polymerization and ring opening under strong acidic conditions.
  • the liquid crystal material may further contain a dioxetane compound represented by the following general formula (5) together with the liquid crystal compound.
  • a liquid crystal compound among the dioxetane compounds is used as the liquid crystal material alone as the liquid crystal compound (when no other liquid crystal compound is used)
  • the liquid crystal compound refers to a liquid crystal compound other than the dioxetane compound.
  • the dioxetane compound represented by the following general formula (5) can be used regardless of the presence or absence of liquid crystallinity, but exhibits liquid crystallinity from the viewpoint of preventing a decrease in liquid crystallinity due to the inclusion of the dioxetane compound. Those are preferred.
  • each R 7 independently represents hydrogen, a methyl group or an ethyl group
  • each L 3 independently represents a single bond or — (CH 2 ) n — (n is 1 to 12).
  • X 1 represents each independently a single bond, —O—, —O—CO— or —CO—O—
  • M 1 represents the following general formula (6) or the following general formula ( 7) is any one represented by, P 1 in the following general formula (6) and the following general formula (7) represents each independently a group selected from the following general formula (8), P 2 is below
  • L 4 represents a group selected from general formula (9), and each L 4 independently represents a single bond, —CH ⁇ CH—, —C ⁇ C—, —O—, —O—CO— or —CO—O—.
  • Et, iPr, nBu, and tBu represent an ethyl group, an isopropyl group, a normal butyl group, and a tertiary butyl group, respectively.
  • the linking groups connecting the left and right oxetane groups as viewed from the M 1 group may be the same (symmetrical) or different (asymmetrical), and the liquid crystallinity depends on the structure. It is different but not necessary.
  • the compound represented by the general formula (5) is a number of compounds from a combination of L 3, X 1 and M 1 are exemplified, preferably may be mentioned the following compounds.
  • the dioxetane compound represented by the general formula (5) can be synthesized according to a usual synthesis method in organic chemistry, and the synthesis method is not particularly limited.
  • the (meth) acrylic compound and the dioxetane compound which have the said oxetane group with the said liquid crystalline compound as the said liquid crystalline material when using the said liquid crystalline material as a liquid crystalline composition, such a liquid crystalline composition
  • the content ratio of the liquid crystalline compound, the (meth) acrylic compound having the oxetane group, and the dioxetane compound in a mass ratio Is preferably in the range of 1 to 30: 100: 0 to 40, and more preferably in the range of 3 to 20: 100: 0 to 30.
  • the content of the liquid crystal compound itself in the liquid crystal layer formed of such a liquid crystal material is preferably 70 to 95% by mass, and more preferably 75 to 95% by mass. If the content of such a liquid crystal compound is less than the lower limit, there is a tendency that a sufficient retardation is not exhibited. On the other hand, if the content exceeds the upper limit, the orientation tends to be lowered.
  • a photo cation generator and / or a thermal cation generator in some cases, generating cations by external stimulation such as light and heat
  • the cation generator may be used in combination with various sensitizers as necessary.
  • Such a photo cation generator is not particularly limited, and a compound capable of generating a cation by irradiating with light having an appropriate wavelength can be appropriately used.
  • a compound capable of generating a cation by irradiating with light having an appropriate wavelength can be appropriately used.
  • an organic sulfonium salt type, an iodonium salt type, a phosphor type can be used.
  • a compound such as a phonium salt can be used as appropriate.
  • antimonate, phosphate, borate and the like are preferably used as the counter ion of the compound used in such a photocation generator.
  • examples of the compound used for such a photocation generator include, for example, the formula: Ar 3 S + SbF 6 ⁇ , Ar 3 P + BF 4 ⁇ , Ar 2 I + PF 6 ⁇ (wherein Ar represents a phenyl group or a substituted phenyl group.), Sulfonate esters, triazines, diazomethanes, ⁇ -ketosulfone, iminosulfonate, benzoinsulfonate, and the like. More specific examples of such a photocation generator include triallylsulfonium hexafluoroantimonate and triallylsulfonium hexafluorophosphate. Moreover, you may utilize a commercial item.
  • the thermal cation generator is not particularly limited, and a compound capable of generating a cation when heated to an appropriate temperature can be appropriately used.
  • benzylsulfonium salts benzylammonium salts, benzylpyridinium salts
  • Benzylphosphonium salts hydrazinium salts, carboxylic acid esters, sulfonic acid esters, amine imides, antimony pentachloride-acetyl chloride complexes, diaryliodonium salts-dibenzyloxycopper, boron halide-tertiary amine adducts, etc.
  • the amount of such a cation generator added to the liquid crystal material varies depending on the structure of the mesogen portion and spacer portion of the liquid crystal compound contained in the liquid crystal material, the equivalent of the oxetane group, the alignment condition of the liquid crystal compound, and the like. Therefore, for example, when the side-chain liquid crystalline polymer is used as the liquid crystalline compound, the content is set to 100 mass ppm to 20 mass% with respect to the side-chain liquid crystalline polymer. It is preferably 1000 mass ppm to 10 mass%, more preferably 0.5 mass% to 8 mass%, and most preferably 1 mass% to 6 mass%.
  • the liquid crystal material may contain a solvent from the viewpoint of coating properties at the time of forming the liquid crystal layer.
  • a solvent is not particularly limited as long as it can dissolve various compounds used in the liquid crystal material, can be distilled off under suitable conditions at the time of immobilization, and has little influence on the substrate.
  • various solvents can be used as appropriate.
  • solvents examples include ketones such as acetone, methyl ethyl ketone, isophorone, and cyclohexanone, ether alcohols such as butoxyethyl alcohol, hexyloxyethyl alcohol, methoxy-2-propanol, and benzyloxyethyl alcohol, ethylene glycol dimethyl ether, Glycol ethers such as diethylene glycol dimethyl ether, esters such as ethyl acetate, ethyl lactate and ⁇ -butyrolactone, phenols such as phenol and chlorophenol, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. Of these, halogenated compounds such as chloroform, tetrachloroethane, dichlorobenzene, and the like, and mixed systems thereof are preferably used.
  • ketones such as acetone, methyl ethyl ketone, isophor
  • Such solvents may be used alone or in combination of two or more.
  • a solvent is not particularly limited, and may be appropriately set in accordance with the type of liquid crystal compound used, the type of other components, the content thereof, and the like.
  • the content of the solvent is preferably 70 to 99% by mass, and more preferably 75 to 95% by mass. If the content of such a solvent is less than the lower limit, the coating property tends to be reduced, and if it exceeds the upper limit, coating unevenness due to a decrease in viscosity tends to occur.
  • the liquid crystal material can contain various compounds that can be mixed with the liquid crystal compound as long as the liquid crystal properties are not impaired.
  • compounds miscible with such liquid crystal compounds include radically polymerizable groups such as vinyl groups and (meth) acrylic groups, oxetane groups (excluding compounds having the above oxetane group), oxiranyl groups, vinyloxy groups, and the like.
  • Various polymerizable compounds having a cationic polymerizable group, compounds having a reactive group such as a carboxyl group, an amino group and an isocyanate group, various polymer compounds having a film forming ability, and the like can also be blended.
  • the liquid crystal material is subjected to an alignment treatment, and then the reaction is allowed to proceed using the reactive functional group (depending on the type of the functional group).
  • the reaction is allowed to proceed using the reactive functional group (depending on the type of the functional group).
  • conditions suitable for the reaction can be appropriately adopted.
  • Crosslinking, molecular weight increase and the like can also be achieved, and this can contribute to improvement of the mechanical strength and the like of the intended final product.
  • a reaction initiator, activator, sensitizer, surfactant You may add an antifoamer, a leveling agent, etc. in a liquid-crystal material suitably.
  • the liquid crystal layer may be a layer in which the liquid crystal material is fixed in a homeotropic alignment state, and is not particularly limited. However, after the liquid crystal material is applied on the base material, the liquid crystal layer becomes homeotropic alignment. It is preferably a liquid crystal layer (liquid crystal layer in which the liquid crystal material is fixed in a homeotropic alignment state) obtained by performing an alignment treatment on the liquid crystal and fixing the liquid crystal state.
  • the state that “the liquid crystal material is fixed in a homeotropic alignment state” in the liquid crystal layer means that the liquid crystal material is fixed (for example, a compound having a crosslinking group is introduced into the liquid crystal material for polymerization).
  • Homeotropic alignment (so-called vertical alignment: alignment in which the long-axis molecular direction of the liquid crystal is aligned substantially perpendicular to the substrate) in the liquid crystal layer obtained after being fixed in a glass state) ) Is confirmed, and the component derived from the compound or the like contained in the liquid crystal material (preferably the component derived from the liquid crystal compound (the liquid crystal compound itself, the liquid crystal compound is decomposed and formed) Or a polymer of a liquid crystal compound, etc.))) may be fixed in a homeotropic alignment state.
  • Such an orientation state can be confirmed by performing observation under crossed Nicols using a polarizing microscope.
  • a method suitable for the alignment treatment method, the fixing (curing) method, and the like of the liquid crystal material will be described in the optical film manufacturing method of the present invention described later.
  • the thickness (film thickness) of such a liquid crystal layer varies depending on the application and required characteristics, but is preferably 0.1 to 50 ⁇ m, more preferably 0.2 to 20 ⁇ m, and 0 More preferably, it is 3 to 10 ⁇ m.
  • a film thickness is less than the lower limit, a desired retardation cannot be exhibited.
  • the upper limit is exceeded, the orientation of the liquid crystal tends to deteriorate.
  • the liquid crystal layer may be required to have a specific retardation value as well as a film thickness depending on the use of the optical film.
  • the refractive index in the direction indicating the maximum refractive index direction in the plane of the liquid crystal layer is Nx
  • the refractive index in the direction orthogonal thereto is Ny
  • the refractive index in the thickness direction is Nz
  • the thickness of the liquid crystal layer is d (nm).
  • the relationship of the refractive index of the homeotropic alignment liquid crystal layer is usually Nz> Nx ⁇ Ny.
  • Such Re and Rth are values for light having a wavelength of 550 nm.
  • a hard coat layer is laminated on the substrate.
  • Such a hard coat layer is a layer formed by curing a hard coat material containing a urethane (meth) acrylate resin.
  • the hard coat material used for forming the hard coat layer contains a urethane (meth) acrylate resin
  • the resulting hard coat layer exhibits a high degree of adhesion to the liquid crystal layer. It becomes.
  • the urethane (meth) acrylate resin as described above, the hard coat layer to be formed has sufficient flexibility and curling (warping) can be suppressed.
  • Such urethane (meth) acrylate-based resin is not particularly limited, and known urethane (meth) acrylate-based resins can be appropriately used.
  • acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester Among them, urethane (meth) acrylate resin (urethane acrylate resin and / or urethane methacrylate resin) obtained by using diisocyanate as a raw material compound can be appropriately used.
  • a urethane (meth) acrylate-based resin for example, at least one monomer out of acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester, and a polyol are used to form one hydroxyl group.
  • Urethane acrylate and urethane methacrylate obtained by preparing at least one of hydroxy acrylate and hydroxy methacrylate having one or more hydroxyl groups and then reacting the resulting hydroxy acrylate and / or hydroxy methacrylate with diisocyanate. At least one of them can be used.
  • 1 type may be used independently or 2 or more types may be mixed and utilized.
  • Examples of the methacrylic acid ester that can be used as a raw material compound of such a urethane (meth) acrylate resin include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, and butyl methacrylate; cyclohexyl methacrylate and the like. And cycloalkyl methacrylate.
  • the polyol that can be used as a raw material compound of the urethane (meth) acrylate resin is not particularly limited as long as it is a compound having at least two hydroxyl groups, and examples thereof include ethylene glycol and 1,3-propylene.
  • Glycol 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10 -Decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, hydroxypivalic acid neopentyl glycol ester, tricyclodecane dimethylol, 1,4-cyclohexanediol , Spiroglycol Tricyclodecane dimethylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene oxide-added bisphenol A, trimethylolethane, trimethylolpropane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythri
  • diisocyanate that can be used as a raw material compound of the urethane (meth) acrylate resin for example, various aromatic, aliphatic, or alicyclic diisocyanates can be used.
  • diisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4, Examples thereof include 4-diphenyl diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, and hydrogenated products thereof.
  • the content ratio of each component, reaction conditions, etc. are not particularly limited, and known conditions can be adopted as appropriate, depending on the target product.
  • urethane (meth) acrylate resin those having a weight average molecular weight of 500 to 25000 are preferred, and those having a weight average molecular weight of 500 to 10,000 are particularly preferred.
  • a weight average molecular weight becomes a value outside the above range, the strength of the liquid crystal layer tends to be insufficient or the orientation tends to decrease.
  • Such a weight average molecular weight employs a value determined as a polystyrene-reduced weight average molecular weight based on data obtained by GPC measurement under the condition of using tetrahydrofuran as a separation liquid.
  • urethane (meth) acrylate type resin 1 type may be used independently, or 2 or more types may be mixed and utilized.
  • a urethane (meth) acrylate resin a commercially available urethane (meth) acrylate resin can be used as appropriate.
  • the hard coat material may contain other resin components in addition to the urethane (meth) acrylate resin.
  • Such other resin components are not particularly limited, and are alkyl (meth) acrylate polymers (including copolymers), polyol (meth) acrylates, alkyl (meth) acrylates containing an alkyl group having a substituent. Polymers (including copolymers) and the like can be used as appropriate.
  • At least one polymer, copolymer, or these of alkyl (meth) acrylate containing an alkyl group having at least one substituent of hydroxyl group and acryloyl group It is preferable to contain a combination of the resin component (A) made of a mixture; and polyol (meth) acrylate.
  • the resin component (A) suitably used as such other resin component at least one of alkyl (meth) acrylates containing an alkyl group having at least one substituent of a hydroxyl group and an acryloyl group is used. It may be any kind of polymer, copolymer or mixture thereof, and is not particularly limited.
  • the polyol (meth) acrylate suitable as the other resin component is not particularly limited.
  • pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 1,6- Examples include hexanediol acrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, and 1,6-hexanediol methacrylate.
  • a polyol (meth) acrylate a component composed of a polymer of pentaerythritol triacrylate and pentaerythritol tetraacrylate; a mixed component containing pentaerythritol triacrylate and pentaerythritol tetraacrylate is preferable.
  • Such polyol (meth) acrylates may be used alone or in admixture of two or more.
  • the hard coat material may contain a solvent from the viewpoint of coating properties at the time of forming the hard coat layer.
  • a solvent is not particularly limited, and various solvents can be appropriately used. Examples of such solvents include dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, acetone, and methyl ethyl ketone.
  • MEK diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, n acetate -Pentyl, acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pe Tanol, 2-methyl-2-butanol, cyclohexanol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, 2-heptanone,
  • a leveling agent may be added to the hard coat material as long as the effects of the present invention are not impaired.
  • a leveling agent include a fluorine-based or silicone-based leveling agent.
  • a silicone type leveling agent is preferable.
  • the silicone leveling agent is not particularly limited, and examples thereof include reactive silicone, polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane.
  • the reactive silicone is particularly preferable.
  • a pigment in the hard coat material, as long as the effects of the present invention are not impaired, a pigment, a filler, a dispersant, a plasticizer, an ultraviolet absorber, a surfactant, an antifouling agent, an antioxidant, a thixotropic agent, if necessary.
  • a pigment such as an agent.
  • Such additives may be used alone or in combination of two or more.
  • a known photopolymerization initiator can be used for the hard coat material according to the type of resin component used.
  • a photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (IRG-184), 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, 3-methylacetophenone, 4-chlorobenzophenone.
  • the content of the urethane (meth) acrylate resin in the hard coat material is not particularly limited, but from the viewpoint of the hardness of the obtained hard coat layer, the resin component in the hard coat material
  • the total amount is preferably 15 to 55% by mass, more preferably 25 to 45% by mass.
  • the total amount of the resin component referred to here means the total amount of the resin component contained in the hard coat material.
  • the resin component (A) or polyol (meta) together with the urethane (meth) acrylate resin are examples of the total amount of the resin component contained in the hard coat material.
  • acrylate When further containing acrylate, it refers to the total amount (total amount) of urethane (meth) acrylate resin, resin component (A) and polyol (meth) acrylate, and when further containing other resin components The amount (total amount) obtained by further adding the amount of other resin components to the total amount. Further, when the content of such urethane (meth) acrylate resin is less than the lower limit, the cured product physical properties such as hardness tend to be lowered. On the other hand, when the upper limit is exceeded, the curling of the film is sufficiently prevented. Tend to be difficult.
  • the total amount of such resin components is preferably 90 to 99.9% by mass, and more preferably 95 to 99.5% by mass in the hard coat material. If the total amount of such resin components is less than the lower limit, it tends to be difficult to efficiently form a hard coat layer, whereas if it exceeds the upper limit, it tends to be difficult to control the thickness of the hard coat layer. is there.
  • the content of the resin component (A) is not particularly limited, but the urethane (meth) acrylate resin 100 mass.
  • the amount is preferably 25 to 110 parts by mass, more preferably 45 to 85 parts by mass with respect to parts.
  • the content of the resin component (A) exceeds the upper limit, the coatability of the hard coat material tends to be reduced, and on the other hand, when the blending ratio of the resin component (A) is less than the lower limit.
  • the hard coat material is cured, it becomes difficult to prevent curing shrinkage, and it tends to be difficult to sufficiently prevent the occurrence of curling.
  • the content of the polyol (meth) acrylate is not particularly limited, but 100 parts by mass of the urethane (meth) acrylate resin The amount is preferably 70 to 180 parts by mass, and more preferably 100 to 150 parts by mass. If the content of the polyol (meth) acrylate exceeds the upper limit, it becomes difficult to efficiently prevent curing shrinkage during the formation of the hard coat layer, and curling of the hard coat layer cannot be sufficiently prevented. It is difficult to sufficiently prevent the deterioration of the property. Moreover, if content of the said polyol (meth) acrylate is less than the said minimum, it will become difficult to make hardness of a hard-coat layer sufficient, and it exists in the tendency for abrasion resistance to fall.
  • the content of the solvent is preferably 95% by mass or less, and more preferably 90% by mass or less.
  • the content of such a solvent exceeds the above upper limit, the leveling property tends to be lowered and coating unevenness tends to occur.
  • the content of the leveling agent is not particularly limited, but is preferably 5 parts by mass or less, and 0.01 to 5 parts by mass with respect to 100 parts by mass of the total resin component. Is more preferable.
  • a hard-coat material the preparation method of each component, its mixing method, etc. are not restrict
  • a hard-coat material what is necessary is just to contain the said urethane (meth) acrylate type-resin, and you may utilize a commercial item suitably, for example, the brand name by Taisei Fine Chemical Co., Ltd. “8UX-015A”, trade name “Aronix M-1100” manufactured by Toagosei Co., Ltd., etc. can be used.
  • the hard coat layer is a layer formed by curing the hard coat material, and suitable conditions for such curing will be described in the optical film production method of the present invention described later.
  • the content of the component derived from the urethane (meth) acrylate resin in the hard coat layer (resin layer) is 15 to 55.
  • the content is preferably mass%, more preferably 25 to 45 mass%. If such a content is less than the lower limit, the cured product physical properties such as hardness tend to be lowered. On the other hand, if it exceeds the upper limit, it tends to be difficult to sufficiently prevent the curling of the film.
  • the thickness (film thickness) of such a hard coat layer is preferably 15 ⁇ m or less, more preferably 0.1 to 5 ⁇ m, and further preferably 0.1 to 3 ⁇ m. If such a thickness is less than the lower limit, it becomes difficult to impart sufficient hardness to the hard coat layer, and the scratch resistance tends to decrease.On the other hand, if the upper limit is exceeded, curling increases at the time of curing. When the film is formed, the line running property tends to be lowered when the hard coat material is applied.
  • the hardness of such a hard coat layer is also affected by the thickness of the layer, and is not particularly limited.
  • the pencil hardness preferably has a hardness of 6B to 4H. More preferably, it has a hardness of 5B to 2H. When such hardness is less than the lower limit, scratch resistance tends to be reduced, and when it exceeds the upper limit, crack resistance tends to be reduced.
  • Such a pencil hardness value can be obtained by measuring in accordance with a method defined in JIS K5600-5-4 issued in 1999.
  • Such an optical film of the present invention only needs to include the base material, the liquid crystal layer, and the hard coat layer, and the production method of the optical film of the present invention described later is suitable as the production method. Can be adopted.
  • a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state is laminated on a base material, and then a hard coat material containing a urethane (meth) acrylate resin on the liquid crystal layer Apply and cure to laminate a hard coat layer, It is a method of obtaining an optical film provided with the substrate, the liquid crystal layer laminated on the substrate, and the hard coat layer formed by curing the hard coat material laminated on the liquid crystal layer. .
  • any of the “substrate”, “liquid crystal layer”, “hard coat layer”, “liquid crystal material”, “hard coat material” and the like described in the method for producing such an optical film is the optical material of the present invention described above. This is the same as described in the film.
  • any method can be used as long as a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state on a substrate can be laminated on the substrate.
  • the liquid crystal material is applied onto the base material by performing an alignment treatment so as to be homeotropic alignment and fixing the liquid crystal state. It is preferable to employ a method of laminating a liquid crystal layer in which is fixed in a homeotropic alignment state.
  • the method for applying the liquid crystal material on the substrate is not particularly limited, and may be any method that can ensure the uniformity of the coating film according to the type of the liquid crystal material, and does not contain a solvent. Even if it is the method of apply
  • a method for applying such a liquid crystal material is not particularly limited, and a known method can be appropriately employed. For example, a flexographic printing method, an offset printing method, a dispenser method, a gravure coating method, a micro gravure method, a bar Coating methods such as a coating method, a screen printing method, a lip coating method, and a die coating method can be appropriately employed.
  • a gravure coating method it is preferable to employ a gravure coating method, a kiss coating method, a lip coating method, and a die coating method.
  • corona treatment or plasma treatment may be performed as surface modification treatment before coating.
  • a drying step for removing (evaporating) the solvent from the coating film after the application.
  • a drying step is not particularly limited as long as the uniformity of the coating film is maintained, and a known method can be employed, for example, a method such as a heater (furnace), hot air blowing, etc. May be adopted.
  • a heater furnace
  • hot air blowing etc. May be adopted.
  • the film thickness is preferably 0.1 to 50 ⁇ m (more preferably 0.2 to 20 ⁇ m, still more preferably 0.3 to 10 ⁇ m).
  • the orientation tends to be insufficient. Further, when the film thickness after drying is less than the lower limit, a desired phase difference tends not to be expressed. On the other hand, when the film thickness exceeds the upper limit, the orientation of the liquid crystal tends to be lowered.
  • the method of aligning the liquid crystal material so as to be homeotropic alignment after applying the liquid crystal material on the substrate is not particularly limited, and the liquid crystal material in the liquid crystal material is not limited.
  • a known method capable of forming homeotropic alignment can be employed as appropriate.
  • a method of heat-treating the coating film of the liquid crystal material may be employed.
  • the heat treatment is a method of heating within the liquid crystal phase expression temperature range of the liquid crystalline compound in the liquid crystal material, depending on the liquid crystal material used.
  • the conditions can be appropriately set among known conditions.
  • the liquid crystal can be homeotropically aligned by utilizing the self-alignment ability inherent in the liquid crystal compound in the liquid crystal material.
  • the optimum conditions and limit values of the liquid crystal phase behavior temperature vary depending on the type of liquid crystal compound used, etc. Is a temperature within a temperature range of 10 to 200 ° C.
  • the heat treatment temperature is less than the lower limit, the liquid crystal alignment tends not to proceed sufficiently. On the other hand, if the heat treatment temperature exceeds the upper limit, the base material tends to deteriorate, and the strength of the base material tends to be problematic.
  • the time for such heat treatment is not particularly limited as long as the liquid crystal can be homeotropically aligned, but it is preferably 3 seconds to 30 minutes, and preferably 10 seconds to 10 minutes. It is more preferable. When the time for such heat treatment is shorter than 3 seconds, it tends to be difficult to sufficiently complete liquid crystal alignment (homeotropic alignment). On the other hand, when it exceeds 30 minutes, the productivity of the liquid crystal layer is low. It tends to decrease.
  • a known method can be appropriately employed depending on the type of liquid crystal material to be used.
  • a fixing method for example, when a liquid crystal material containing a liquid crystal compound containing a reactive functional group is used, the reactive functional group is reacted by light irradiation and / or heat treatment.
  • a method of fixing the alignment in the homeotropic alignment state may be employed.
  • the reactive functional group is reacted by light irradiation and / or heat treatment to fix the alignment in the homeotropic alignment state.
  • a reaction initiator for example, the above-mentioned cation generator
  • the function of the reaction initiator is expressed to advance the reaction. It is preferable.
  • the reaction initiator when the reaction initiator is contained in the liquid crystal material and the reaction initiator expresses the function of the initiator by irradiation with light (for example, a photocation generator) In the case), the orientation is preferably fixed in the homeotropic orientation state by light irradiation.
  • the light irradiation method is not particularly limited.
  • a light source having a spectrum in the absorption wavelength region of the reaction initiator to be used for example, a metal halide lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, And a method of irradiating light from the light source using a laser or the like.
  • a light source having a spectrum in the absorption wavelength region of the reaction initiator to be used for example, a metal halide lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, And a method
  • the integrated dose of light is preferably 10 to 2000 mJ / cm 2 and more preferably 50 to 1000 mJ / cm 2 as the integrated exposure at a wavelength of 365 nm. preferable.
  • the absorption region of the reaction initiator and the spectrum of the light source are significantly different, or when the liquid crystalline compound itself has the ability to absorb light of the light source wavelength.
  • an appropriate photosensitizer and two or more reaction initiators having different absorption wavelengths are mixed from the viewpoint of fixing (curing) the coating film while maintaining the orientation state more efficiently.
  • a method such as use may be employed.
  • the temperature condition at the time of such light irradiation is preferably a temperature range in which the liquid crystal material takes a liquid crystal alignment, and in order to sufficiently enhance the reaction effect, a liquid crystal phase of Tg or more of the liquid crystalline compound is used. It is preferable to perform light irradiation at a temperature.
  • reaction initiator is contained in the liquid crystal material and the reaction initiator expresses the function of the initiator by heat (for example, in the case of a thermal cation generator).
  • the orientation is preferably fixed in a homeotropic orientation state by heat treatment.
  • the conditions for such heat treatment are not particularly limited, and the temperature conditions may be selected according to the type of the reaction initiator so that the orientation state is sufficiently maintained, and known conditions are appropriately employed. Can do.
  • the liquid crystal material is homeotropically aligned by fixing the liquid crystal state by performing an alignment treatment so as to be homeotropic alignment.
  • a liquid crystal layer fixed in an aligned state can be stacked.
  • a method for applying such a hard coat material is not particularly limited, and a known method can be appropriately employed. For example, a fountain coat method, a die coat method, a spin coat method, a spray coat method, a gravure, etc. Coating methods such as a coating method, a roll coating method, and a bar coating method can be used.
  • a step of drying the coating film is preferably performed prior to the curing step.
  • the drying method employed in such a drying step is not particularly limited, and a known method can be employed as appropriate. For example, natural drying, air drying by blowing air, or heat drying can be used. There may be a method that combines these methods.
  • the film thickness at the time of applying such a hard coat material is appropriately determined depending on the type of the hard coat material to be used and the like, and thus cannot be generally determined, but the film thickness after drying is 0. It is preferable that the thickness is 1 to 15 ⁇ m (more preferably 0.1 to 10 ⁇ m, still more preferably 0.1 to 5 ⁇ m). If the film thickness after drying is less than the lower limit, uneven drying tends to occur frequently. On the other hand, if the film thickness exceeds the upper limit, it tends to be difficult to sufficiently prevent curling after curing.
  • a polymer is formed on the surface of the coating film from the viewpoint of preventing curing reaction inhibition by oxygen.
  • a film for example, polyethylene terephthalate (PET) film, triacetyl cellulose (TAC) film, polycarbonate film, polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), etc.
  • PET polyethylene terephthalate
  • TAC triacetyl cellulose
  • PEN polyethylene naphthalate
  • PPS polyphenylene sulfide
  • the method for curing the coating film of the hard coat material is not particularly limited, but it is preferable to employ a method of curing by heat or a method of curing by irradiating the hard coat material with ionizing radiation. It is more preferable to employ a method of curing by irradiating the material with ionizing radiation.
  • various active energy rays can be used as the ionizing radiation, and although not particularly limited, UV) is preferably used.
  • a source of such active energy rays a known radiation source can be used as appropriate, and is not particularly limited, but is not limited to a high pressure mercury lamp, halogen lamp, xenon lamp, metal halide lamp, nitrogen laser, electron beam acceleration.
  • a radiation source such as an apparatus or a radioactive element can be preferably used.
  • the irradiation amount of the ionizing radiation is not particularly limited as long as the hard coat material can be cured.
  • the irradiation dose of such ionizing radiation is preferably 50 to 5000 mJ / cm 2 as an integrated exposure dose at an ultraviolet wavelength of 365 nm.
  • the dose of such ionizing radiation is less than 50 mJ / cm 2, it is difficult to sufficiently perform the curing, tend to hardness of the hard coat layer obtained is decreased, while the 5000 mJ / cm 2 If it exceeds, the formed hard coat layer tends to be colored, and the performance of the optical film tends to be lowered.
  • a hard coat material containing a urethane (meth) acrylate resin is applied on the liquid crystal layer and cured.
  • the hard coat layer is obtained by curing the base material, the liquid crystal layer laminated on the base material, and the hard coat material laminated on the liquid crystal layer. It becomes possible to obtain an optical film provided with. And the optical film of the said this invention can be obtained by manufacturing an optical film in this way.
  • the liquid crystal layer and the hard coat are used because the homeotropic alignment liquid crystal layer and the specific hard coat layer are used in combination. Adhesion between the layers can be made sufficiently high, and peeling due to external force can be sufficiently suppressed. Furthermore, in the optical film obtained in this way, the hard coat layer can give sufficiently excellent heat resistance to the liquid crystal layer, so that the orientation state of the liquid crystal layer is sufficiently suppressed from being changed by heat. And deterioration due to heat is sufficiently suppressed. In addition, since such an optical film is provided with the hard coat layer on the liquid crystal layer, the scratch resistance is sufficiently high. For example, other materials (for example, linear polarizing plates), etc.
  • the liquid crystal layer is damaged by contact with the transport roll, or when the optical film and the polarizing plate are integrally processed, In the bonding step, scratches on the liquid crystal layer due to contact of the roll with the surface of the liquid crystal layer and the like are sufficiently suppressed by the hard coat layer, and deterioration in quality due to scratches can be sufficiently suppressed. Therefore, in such an optical film, the characteristics of the liquid crystal layer can be sufficiently maintained and exhibited, and deterioration in quality during use or application to a polarizing plate or the like can be sufficiently suppressed.
  • the use of such an optical film is not particularly limited, and can be appropriately used for, for example, a use capable of utilizing the characteristics of the homeotropic alignment liquid crystal layer.
  • the optical film capable of utilizing the characteristics of the homeotropic alignment liquid crystal layer for example, the homeotropic alignment liquid crystal layer exhibits a predetermined retardation, so that itself is used as a retardation film or the like.
  • an optical member such as a polarizing plate or a retardation plate.
  • such an optical film includes various known polarizing plates (for example, a polarizing element alone or a film having a light-transmitting protective film on both sides or one side of the polarizing element) and various known retardation films (for example, polymer films and liquid crystals). Or a compound formed of a functional compound or a composition) to form a laminate, and may be used as an optical element such as an elliptically polarizing plate, a retardation plate, a color compensation plate, and a viewing angle improving plate.
  • the optical film may be laminated with a plurality of retardation films.
  • Such a laminate can usually be formed using an adhesive or a pressure-sensitive adhesive so as not to cause displacement or distortion in the polarizing plate or the retardation film.
  • an optical film has a liquid crystal layer of homeotropic alignment (vertical alignment) having a larger refractive index in the film thickness direction in its configuration, for example, the field of view of various image display devices. It can be suitably used for materials such as an optical element (polarizing plate, retardation film, etc.) for improving the angle.
  • an optical element polarizing plate, retardation film, etc.
  • the polarizing plate of the present invention comprises the optical film of the present invention.
  • a polarizing plate is not particularly limited, but the optical film of the present invention is known optically so that the characteristics of the homeotropic alignment liquid crystal layer in the optical film of the present invention can be utilized. What is necessary is just to use it as a polarizing plate combining suitably with a member etc., for example, it is good also as an elliptically polarizing plate combining the optical film of the above-mentioned present invention, and a linear polarizing plate. It is good also as a polarizing plate for LCD backlight sides combining. As described above, the configuration of the polarizing plate is not particularly limited.
  • the design can be changed as appropriate, so that it can be used as various polarizing plates.
  • the optical film of the present invention since the optical film of the present invention includes the hard coat layer, a laminate is formed with another optical member (for example, the above-mentioned linear polarizing plate) and the like, and this is used as a polarizing plate.
  • the bonding step it is possible to sufficiently prevent the liquid crystal layer from being damaged due to the contact of the roll with the surface of the liquid crystal layer, and to sufficiently suppress the deterioration of quality due to the scratch.
  • the optical film of the present invention has sufficient scratch resistance due to the hard coat layer, the polarizing plate of the present invention can be efficiently produced while sufficiently suppressing deterioration in quality.
  • Such a polarizing plate of the present invention will be described as an example of an elliptically polarizing plate that can be obtained by laminating a linear polarizing plate on the optical film of the present invention. .
  • Such an elliptically polarizing plate is obtained by laminating and integrating the optical film of the present invention and the linearly polarizing plate.
  • Such a linear polarizing plate is not particularly limited, and a known linear polarizing plate can be appropriately used.
  • one having a protective film on one side or both sides of a polarizer can be used.
  • Such a polarizer is not particularly limited, and various types of polarizers can be used as appropriate.
  • a highly hydrophilic film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or an ethylene / vinyl acetate copolymer partially saponified film.
  • examples include uniaxially stretched films obtained by adsorbing dichroic substances such as iodine and dichroic dyes on molecular films, and polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. .
  • a film obtained by stretching a polyvinyl alcohol film and adsorbing and orienting a dichroic material (iodine, dye) is preferably used.
  • the thickness of such a polarizer is not particularly limited, but is generally about 5 to 80 ⁇ m. Moreover, it does not restrict
  • the protective film which consists of a well-known material can be utilized suitably.
  • Such a protective film is preferably made of a cellulose-based polymer such as triacetyl cellulose from the viewpoints of polarization characteristics and durability.
  • the method of laminating and integrating the optical film and the linear polarizing plate is not particularly limited.
  • the pressure-sensitive adhesive can be appropriately formed on one or both of the surfaces of the optical film and the linear polarizing plate to be laminated with each other. And after forming an adhesive bond layer, it should just carry out pressure bonding.
  • the crimping can be performed either in a leaf-like form or in a long form, and the apparatus to be used may be an apparatus suitable for each form, and examples thereof include a press and a laminator.
  • the material for forming such a pressure-sensitive adhesive layer and / or adhesive layer is not particularly limited, and a known material can be appropriately used.
  • the image display device of the present invention includes the polarizing plate of the present invention.
  • Such an image display device of the present invention only needs to include the polarizing plate of the present invention, and the type of the image display device is not particularly limited, such as a liquid crystal display device, an organic EL display device, and a plasma display.
  • the method for arranging the polarizing plate of the present invention in an image display device is not particularly limited, and a known method can be appropriately used.
  • the image display device of the present invention including the polarizing plate of the present invention includes the optical film of the present invention including a homeotropic alignment (vertical alignment) liquid crystal layer having a larger refractive index in the film thickness direction.
  • the viewing angle of the image display device can be sufficiently widened or the luminance can be sufficiently improved, thereby improving the viewing angle and image quality. Improvement can be sufficiently achieved.
  • the molecular weight of the side chain type liquid crystalline polymer thus obtained was measured by GPC (measurement conditions: using a high-speed GPC device EcoSec HLC-8320GPC manufactured by Tosoh. Columns were TSKgelSuperH4000, TSKgelSuperH1000, TSKgelSuperMP (HZ) -H, TSKgelHultipor H. Column oven temperature: 40 ° C., separation solvent: tetrahydrofuran, flow rate: 0.35 ml / min was adopted), and the weight average molecular weight in terms of polystyrene was 9700.
  • the description of the numerical value in the said General formula (10) represents the component ratio of each unit, and does not mean a block polymer.
  • the laminate of the dried coating film and COP film is heat-treated in an oven at 90 ° C. for 2 minutes to form a liquid crystal material that forms the coating film (liquid crystal layer).
  • a laminate having a coating film (film thickness: 1.1 ⁇ m) in which the liquid crystal material was homeotropically aligned was obtained.
  • a laminate including a coating film in which the liquid crystal material is homeotropically oriented is placed in close contact with an aluminum plate heated to 60 ° C., and from there, a high-pressure mercury lamp lamp is used to radiate 600 mJ / cm 2 ultraviolet light (however, A liquid crystal layer (film thickness) in which the alignment state is fixed and the alignment state is fixed by irradiating a coating film (liquid crystal layer) after the alignment treatment by irradiating a 365 nm wavelength light. A liquid crystal film (liquid crystal layer / COP film) having 1.0 ⁇ m) was obtained.
  • the liquid crystal film thus obtained was observed under a polarizing microscope in which crossed Nicols were used, the film was tilted and light was incident obliquely with uniform monodomain orientation without disclination. When observed with Nicol, light transmission was observed.
  • the optical phase difference of the obtained liquid crystal film was measured using an automatic birefringence meter (trade name “KOBRA21 ADH”) manufactured by Oji Scientific Instruments. In measuring the optical phase difference, when the measurement light is incident from a direction perpendicular or oblique to the surface of the liquid crystal film, the phase difference (in-plane position) in the direction perpendicular to the surface of the liquid crystal film is measured.
  • the phase difference was almost zero, and when the phase difference was measured obliquely in the slow axis direction of the liquid crystal layer, the phase difference value increased with the increase in the incident angle of the measurement light, so the liquid crystal layer was in a homeotropic alignment state. It was confirmed that it was fixed by.
  • the single retardation of the liquid crystal layer in the liquid crystal film (retardation with respect to light having a wavelength of 550 nm) was estimated to be 0 nm for Re and ⁇ 23 nm for Rth.
  • Example 1 On the liquid crystal layer of the liquid crystal film (homeotropic alignment liquid crystal layer / COP film) obtained in Preparation Example 1, a hard coat material containing a urethane acrylate resin (trade name “8UX-015A manufactured by Taisei Fine Chemical Co., Ltd.”) Urethane acrylate resin weight average molecular weight: 1000, solvent: none, nonvolatile component content: 99% by mass) ”and photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, trade name“ Ciba Japan Co., Ltd.
  • a hard coat material containing a urethane acrylate resin trade name “8UX-015A manufactured by Taisei Fine Chemical Co., Ltd.”
  • Urethane acrylate resin weight average molecular weight 1000
  • solvent none
  • nonvolatile component content 99% by mass
  • a polyethylene terephthalate (PET) film was laminated on the surface of the membrane.
  • the hard coat material is cured by irradiating the coating film with ultraviolet light of 600 mJ / cm 2 from the PET film side (however, the amount of light measured at a wavelength of 365 nm) to form a hard coat layer.
  • a multilayer film having a layer structure of PET film / hard coat layer / homeotropic liquid crystal layer / COP film was obtained (the thickness of the hard coat layer was 1.5 ⁇ m).
  • the PET film was peeled off from the obtained multilayer film to obtain an optical film (layer structure of COP film / homeotropic alignment liquid crystal layer / hard coat layer).
  • a liquid crystal material (liquid crystal composition) in a solution state was prepared by employing the same method as that employed in Preparation Example 1.
  • PVA / PEN PVA uses the product name “PXP-05” manufactured by Nihon Vinegar Bipoval Co., Ltd.
  • PEN uses the product name manufactured by Teijin Ltd.
  • the laminate of the dried coating film and the substrate film (PVA / PEN film) is subjected to heat treatment for 1 minute using an oven at 145 ° C., and once the laminate after heat treatment is taken out of the oven at room temperature ( After cooling to 25 ° C.), the coated film (liquid crystal) is subjected to heat treatment for 1 minute 30 seconds using an oven at 145 ° C. with respect to the cooled laminate.
  • the liquid crystal material forming the layer) was aligned to obtain a laminate including a coating film (film thickness 1.1 ⁇ m) in which the liquid crystal material was homogeneously aligned.
  • the laminate including the coating film in which the liquid crystal material is homogeneously oriented is placed in close contact with an aluminum plate heated to 60 ° C., and from there, a high-pressure mercury lamp lamp is used to emit 600 mJ / cm 2 ultraviolet light (however, A liquid crystal layer (film thickness 1) in which the alignment state is fixed by irradiating the coating film (liquid crystal layer) after the alignment treatment by irradiating 365 nm wavelength light). .Mu.m) (liquid crystal layer / substrate film [PVA / PEN] layer structure).
  • a UV curable acrylic resin (UV-3400 manufactured by Toagosei Co., Ltd.) was applied on the liquid crystal layer of the film thus obtained to form a coating film, and then the surface of the coating film was triacetylcellulose (TAC). It was covered with a film (trade name “TDY80” manufactured by FUJIFILM Corporation) to obtain a laminated body (TAC / UV-3400 / liquid crystal layer / PVA / PEN layer structure). Next, 600 mJ / cm 2 of ultraviolet light (however, the amount of light measured at a wavelength of 365 nm) is irradiated from above the obtained laminate with a high-pressure mercury lamp lamp to cure the acrylic resin coating film. Thereafter, the substrate film (PVA / PEN film) was peeled from the laminate to obtain a liquid crystal film (TAC / UV-3400 / layer structure of liquid crystal layer).
  • TAC triacetylcellulose
  • the liquid crystal film (homeotropic alignment liquid crystal layer / COP film) obtained in Preparation Example 1 was used instead of the liquid crystal film (homeotropic alignment liquid crystal layer / COP film) obtained in Preparation Example 1. Except for the above, a hard coat layer was formed on the liquid crystal layer in the same manner as in Example 1 to obtain an optical film (TAC / UV-3400 / liquid crystal layer / hard coat layer layer structure). When the alignment state of the liquid crystal layer was observed with crossed Nicols, it was confirmed that the liquid crystal layer was fixed in a homogeneous alignment state.
  • a liquid crystal material (liquid crystal composition) in a solution state was prepared by employing the same method as that employed in Preparation Example 1.
  • PVA / PEN PVA uses the product name “PXP-05” manufactured by Nihon Vinegar Bipoval Co., Ltd.
  • PEN uses the product name manufactured by Teijin Ltd.
  • the laminate of the dried coating film and the substrate film (PVA / PEN film) is subjected to heat treatment for 1 minute using an oven at 145 ° C., and once the laminate after heat treatment is taken out of the oven at room temperature ( After cooling to 25 ° C.), the coated layer (liquid crystal layer) is subjected to heat treatment for 1 minute and 30 seconds using a 125 ° C. oven on the cooled laminate. ) Was aligned to obtain a laminate including a coating film (film thickness 1.1 ⁇ m) in which the liquid crystal material was spray aligned.
  • the laminate including the coating film in which the liquid crystal material is spray-oriented is placed in close contact on an aluminum plate heated to 60 ° C., and from there, a high-pressure mercury lamp lamp is used to emit 600 mJ / cm 2 ultraviolet light (however, A liquid crystal layer (film thickness 1) in which the alignment state is fixed by irradiating the coating film (liquid crystal layer) after the alignment treatment by irradiating 365 nm wavelength light). .Mu.m) (liquid crystal layer / substrate film [PVA / PEN] layer structure).
  • a UV curable acrylic resin (UV-3400 manufactured by Toagosei Co., Ltd.) was applied on the liquid crystal layer of the film thus obtained to form a coating film, and then the surface of the coating film was triacetylcellulose (TAC). It was covered with a film (trade name “TDY80” manufactured by FUJIFILM Corporation) to obtain a laminated body (TAC / UV-3400 / liquid crystal layer / PVA / PEN layer structure). Next, 600 mJ / cm 2 of ultraviolet light (however, the amount of light measured at a wavelength of 365 nm) is irradiated from above the obtained laminate with a high-pressure mercury lamp lamp to cure the acrylic resin coating film. Thereafter, the substrate film (PVA / PEN film) was peeled from the laminate to obtain a liquid crystal film (TAC / UV-3400 / layer structure of liquid crystal layer).
  • TAC triacetylcellulose
  • both of the optical films obtained in Example 1 and Comparative Example 1 have substantially the same front phase difference and phase difference in the oblique direction (50 °). It was confirmed that there was almost no change in the retardation by laminating the hard coat layer. From these results, it was confirmed that the characteristics of the liquid crystal layer can be sufficiently maintained in the laminating step of the hard coat layer as compared with before the laminating.
  • Example 1 and Comparative Examples 2 to 4 The interlayer adhesion of each optical film obtained in Example 1 and Comparative Examples 2 to 4 was measured as follows. That is, first, using each of the optical films obtained in Examples and the like, using a laminator (manufactured by Musashinokikai Co., Ltd.) and a roll speed of 0.75 m / min, a separator / adhesive layer / optical film (base material ( COP film or TAC / UV-3400 laminated film) / liquid crystal layer / hard coat layer) / cello tape (registered trademark) were prepared.
  • a laminator manufactured by Musashinokikai Co., Ltd.
  • separator / adhesive layer / optical film base material ( COP film or TAC / UV-3400 laminated film) / liquid crystal layer / hard coat layer
  • cello tape registered trademark
  • a double-sided tape having a configuration of separator / adhesive layer / separator (double-sided tape manufactured by Nitto Denko Corporation (trade name “N501F”)) is used.
  • the separator was peeled off, and the adhesive layer was in contact with the surface of the base material (COP film or TAC / UV-3400 laminated film), and the cello tape (registered trademark) was manufactured by Nichiban Co., Ltd.
  • the trade name “CT-18S” was used (cello tape (registered trademark) was placed on the surface of the hard coat layer.) From each of the laminated samples thus obtained, the length was 100 mm and the width was 25 mm.
  • the separator in the strip-shaped sample is peeled off, and the sample is bonded to the glass preparation, and the interlayer adhesion is A test sample for evaluation was used, and using the test sample, Cellotape (registered trademark) was placed in a 90 ° direction from the surface of the test sample according to the product name “Strograph EL” manufactured by Toyo Seiki Co., Ltd.
  • Example 1 As is apparent from the results shown in Table 2, in the optical film obtained in Example 1, the average adhesion between the hard coat layer / homeotropic alignment liquid crystal layer (the hard coat layer was peeled off from the homeotropic liquid crystal layer). (Average value of the moment of force applied) was 462 N / m (Example 1). In the optical film obtained in Example 1, the adhesion between the layers of the hard coat layer / homeotropic liquid crystal layer was Was confirmed to be sufficiently excellent. On the other hand, in the optical film obtained in Comparative Example 2, it was confirmed that the average adhesion was 434 N / m.
  • the average adhesion is as low as 24 N / m and 35 N / m, respectively, and the alignment state of the liquid crystal layer is in a state other than homeotropic alignment. It was also confirmed that sufficient adhesion could not be obtained even if a hard coat material containing a urethane (meth) acrylate resin was laminated.
  • a hard coat containing a (meth) acrylate resin other than a urethane (meth) acrylate resin by using a hard coat material containing a urethane (meth) acrylate resin as the material of the hard coat layer. It was confirmed that a higher level of adhesion was achieved compared to the material. Further, it was confirmed that when a hard coat material containing a urethane (meth) acrylate resin is used, a sufficiently high adhesion can be imparted specifically and specifically to a liquid crystal layer having homeotropic alignment.
  • cleaning cloths manufactured by Kuraray Co., Ltd.
  • Comparative Example 1 an optical film for comparison (Comparative Example 1) not laminated with a hard coat layer, respectively.
  • Product name “Crinesta”) while applying a load of 750 g on the cleaning cloth, the surface of each optical film (surface opposite to the substrate) was reciprocated 10 times, The state of scratches on the surface of the optical film was confirmed with a polarizing microscope.
  • the optical film for comparison Comparative Example 1
  • the hard coat layer was scratched. It was confirmed that the scratch did not reach the liquid crystal layer, and the hard coat layer sufficiently prevented the liquid crystal layer from being scratched.
  • Example 1 and Comparative Examples 1 and 2 In order to evaluate the heat resistance of each optical film obtained in Example 1 and Comparative Examples 1 and 2, first, a sample was prepared by cutting each optical film into a rectangular size of 3 cm ⁇ 4 cm. A laminate of a 25 ⁇ m thick adhesive layer and a separator film (general LCD grade non-carrier glue) is bonded to the surface of the hard coat layer, and then the separator film is peeled off to form a glass plate (2 mm thick). A sample for heat resistance evaluation was obtained, which was laminated and laminated in the order of glass / adhesive layer / hard coat layer / homeotropic liquid crystal layer / COP film.
  • a separator film generally LCD grade non-carrier glue
  • a blank sample without heat treatment was also prepared in order to compare and evaluate the state of the homeotropic liquid crystal layer before and after heat treatment by adopting a method similar to such a sample preparation method. Then, the heat resistance evaluation sample was subjected to a heat treatment in a dry oven (“Pile-up oven TAH-21H” manufactured by Thomas Scientific Instruments Co., Ltd.) under a dry condition at 90 ° C. (total heating Time: 515 hours).
  • a dry oven (“Pile-up oven TAH-21H” manufactured by Thomas Scientific Instruments Co., Ltd.) under a dry condition at 90 ° C. (total heating Time: 515 hours).
  • the phase difference (retardation in the thickness direction: Rth) between the heat-treated sample thus obtained and the non-heat-treated sample (blank sample) is measured, and the Rth of the sample after heat treatment with respect to the blank sample is measured.
  • the variation rate (%) was measured, and the heat resistance was evaluated based on the variation rate of Rth.
  • the thickness direction retardation (Rth) of the sample was measured at the stage where the heating time of the heat treatment was 24 hours, 144 hours, 312 hours, and 515 hours.
  • the Rth of the sample after the passage of time was determined.
  • the phase difference was measured using an automatic birefringence meter (trade name “KOBRA21 ADH”) manufactured by Oji Scientific Instruments Co., Ltd., using light having a wavelength of 590 nm. The obtained results are shown in Table 4 and FIG.
  • the adhesion between the liquid crystal layer and the hard coat layer can be made sufficiently high, and the liquid crystal layer is formed by the hard coat layer.
  • an optical film with sufficiently suppressed quality deterioration deterioration due to heat and scratches
  • the adhesion between the homeotropic alignment liquid crystal layer and the hard coat layer can be sufficiently advanced, and has a sufficiently high scratch resistance, It is possible to provide an optical film having sufficiently excellent heat resistance and capable of sufficiently suppressing the change in the alignment state of the liquid crystal layer due to heat, and a method for producing the same.
  • the optical film of the present invention is particularly useful as a material for use in an optical element (for example, a polarizing plate, a retardation film, etc.) for use in various image display devices.
  • an optical element for example, a polarizing plate, a retardation film, etc.

Abstract

Provided is an optical film, comprising a substrate, a liquid-crystal layer which is stacked upon the substrate, and a hard coat layer which is stacked upon the liquid-crystal layer. The liquid-crystal layer is a layer wherein a liquid-crystal material is fixed in a homeotropic orientation. The hard coat layer is a layer formed by curing a hard coat material including a urethane (meth)acrylate resin.

Description

光学フィルム、偏光板、画像表示装置及び光学フィルムの製造方法Optical film, polarizing plate, image display device, and method of manufacturing optical film
　本発明は、光学フィルム、偏光板、画像表示装置並びに光学フィルムの製造方法に関する。 The present invention relates to an optical film, a polarizing plate, an image display device, and a method for manufacturing an optical film.
　近年、画像表示装置等の分野においては、視野角向上や画質向上等の観点から、偏光板、反射防止板、位相差板等が利用されている。そして、このような偏光板、反射防止板、位相差板等の材料として、複屈折性（光学的異方性）等の光学特性を有する液晶層を備える光学フィルムの応用が検討されてきた。しかしながら、そのような液晶層を備える光学フィルムは、前記液晶層の表面に異物が接触した場合に容易に傷が付き、複屈折性等の光学特性が変化してしまうといった問題があった。そのため、このような光学フィルムにおいては、前記液晶層に傷がついて複屈折性などの性能が変化することを防止するために、前記液晶層にハードコート層（オーバーコート層）を形成させることが提案されている。 In recent years, polarizing plates, antireflection plates, retardation plates and the like have been used in the field of image display devices and the like from the viewpoint of improving the viewing angle and improving image quality. In addition, as a material for such a polarizing plate, an antireflection plate, a retardation plate, etc., application of an optical film having a liquid crystal layer having optical properties such as birefringence (optical anisotropy) has been studied. However, an optical film including such a liquid crystal layer has a problem that when a foreign object comes into contact with the surface of the liquid crystal layer, the optical film is easily scratched and optical characteristics such as birefringence change. Therefore, in such an optical film, a hard coat layer (overcoat layer) can be formed on the liquid crystal layer in order to prevent the liquid crystal layer from being scratched and the performance such as birefringence from changing. Proposed.
　例えば、特開２００９－７５５３５号公報（特許文献１）においては、透明基材上に複屈折層が形成され、更に、前記複屈折層上にハードコート層が形成されている光学フィルムが開示されており、かかる複屈折層は、液晶性ポリマー（例えばリオトロピック液晶性ポリマー等）を含有する溶液を塗布・乾燥することによって形成した層であってもよいことが開示されている。 For example, Japanese Patent Application Laid-Open No. 2009-75535 (Patent Document 1) discloses an optical film in which a birefringent layer is formed on a transparent substrate, and a hard coat layer is further formed on the birefringent layer. It is disclosed that such a birefringent layer may be a layer formed by applying and drying a solution containing a liquid crystalline polymer (for example, a lyotropic liquid crystalline polymer).
特開２００９－７５５３５号公報JP 2009-75535 A
　しかしながら、上記特許文献１においては、液晶性ポリマーからなる複屈折層の特性が熱によって変化してしまうことを抑制するという観点からハードコート層を利用すること等は何ら記載されておらず、また、光学フィルムに液晶性ポリマーの配向状態を特定の状態で固定化した液晶層を備えることについても具体的な開示はない。 However, in the above-mentioned Patent Document 1, there is no description of using a hard coat layer from the viewpoint of suppressing the property of the birefringent layer made of a liquid crystalline polymer from being changed by heat, and Also, there is no specific disclosure about providing an optical film with a liquid crystal layer in which the alignment state of the liquid crystalline polymer is fixed in a specific state.
　本発明は、ホメオトロピック配向の液晶層とハードコート層との間の密着性を十分に高度なものとすることができ、十分に高度な耐傷性を有するとともに、十分に優れた耐熱性を有し、熱により前記液晶層の配向状態が変化することを十分に抑制することが可能な光学フィルム及びその製造方法を提供することを目的とする。 In the present invention, the adhesion between the homeotropic alignment liquid crystal layer and the hard coat layer can be made sufficiently high, and it has a sufficiently high scratch resistance and a sufficiently excellent heat resistance. And it aims at providing the optical film which can fully suppress that the orientation state of the said liquid-crystal layer changes with a heat | fever, and its manufacturing method.
　本発明者らが鋭意研究を重ねた結果、先ず、上記特許文献１に記載のような従来のハードコート材料は、液晶材料をホメオトロピック配向の状態で固定化した液晶層（以下、場合により単に「ホメオトロピック配向液晶層」という。）に対して、十分に高度な密着力でハードコート層を積層するという点において、必ずしも十分なものではないことを見出した。ここにおいて、本発明者らは、配向状態が異なる液晶層（ホメオトロピック配向、ホモジニアス配向、スプレー配向等の液晶層）に対して、それぞれ、同じハードコート材料からなるハードコート層を積層しても、液晶層の配向状態によってハードコート層の密着力が異なり、特定の配向が固定化された液晶層に十分に高度な密着力を示すハードコート層を、別の配向が固定化された液晶層にそのまま適用しても、必ずしも十分に高度な密着力が得られないことも併せて見出している。また、配向状態をホメオトロピック配向の状態で固定化した液晶層が他の配向状態で固定化した液晶層と比較して、特に熱による配向のゆがみによって、その性能が大きく低下する傾向にあることに着目し、本発明者らが更に研究を重ねたところ、特許文献１に記載のような従来のハードコート材料からなるハードコート層では、ホメオトロピック配向の液晶層に対して必ずしも十分な耐熱性を付与することができず、熱による光学フィルムの品質の劣化を十分に抑制することができないことも見出した。そこで、このような従来のハードコート層の問題点を解決すべく、本発明者らが更に鋭意研究を重ねた結果、基材と、前記基材上に積層された液晶層と、前記液晶層上に積層されたハードコート層とを備える光学フィルムにおいて、前記液晶層をホメオトロピック配向の状態で液晶材料を固定化した層とし、ハードコート層をウレタン（メタ）アクリレート系樹脂を含むハードコート材料を硬化してなる層とすることにより、驚くべきことに、ホメオトロピック配向の液晶層とハードコート層との間において十分に高度な密着性が得られ、かかるハードコート層により、前記液晶層に対して十分に高度な耐傷性を付与できるとともに十分に優れた耐熱性を付与することもでき、熱により液晶層の配向状態が変化することを十分に抑制することが可能なことを見出して、本発明を完成するに至った。 As a result of extensive studies by the present inventors, first, a conventional hard coat material as described in Patent Document 1 described above is a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state (hereinafter simply referred to as a case in some cases). It was found that this is not necessarily sufficient in terms of laminating a hard coat layer with a sufficiently high adhesion to “homeotropic alignment liquid crystal layer”. Here, the present inventors may laminate hard coat layers made of the same hard coat material on liquid crystal layers having different alignment states (liquid crystal layers such as homeotropic alignment, homogeneous alignment, and spray alignment), respectively. A liquid crystal layer in which a hard coat layer having a sufficiently high adhesion to a liquid crystal layer in which a specific alignment is fixed and a different alignment is fixed in a liquid crystal layer in which the adhesion of the hard coat layer varies depending on the alignment state of the liquid crystal layer It has also been found that even if it is applied as it is, a sufficiently high adhesion cannot always be obtained. In addition, the liquid crystal layer fixed in the homeotropic alignment state has a tendency to greatly decrease its performance, particularly due to the alignment distortion caused by heat, as compared with the liquid crystal layer fixed in other alignment states. As a result of further research conducted by the present inventors, the hard coat layer made of a conventional hard coat material as described in Patent Document 1 does not necessarily have sufficient heat resistance to a liquid crystal layer having homeotropic alignment. It was also found that the deterioration of the quality of the optical film due to heat cannot be sufficiently suppressed. Therefore, in order to solve the problems of the conventional hard coat layer, as a result of further extensive research by the present inventors, a base material, a liquid crystal layer laminated on the base material, and the liquid crystal layer An optical film comprising a hard coat layer laminated thereon, wherein the liquid crystal layer is a layer in which a liquid crystal material is fixed in a homeotropic alignment state, and the hard coat layer includes a urethane (meth) acrylate resin Surprisingly, a sufficiently high adhesion can be obtained between the homeotropic alignment liquid crystal layer and the hard coat layer, and the hard coat layer can provide the liquid crystal layer with the hardened layer. In addition to providing sufficiently high scratch resistance, it can also provide sufficiently excellent heat resistance and sufficiently suppress changes in the alignment state of the liquid crystal layer due to heat. We have found that it is possible, which resulted in the completion of the present invention.
　すなわち、本発明の光学フィルムは、基材と、前記基材上に積層された液晶層と、前記液晶層上に積層されたハードコート層とを備える光学フィルムであって、
　前記液晶層が液晶材料をホメオトロピック配向の状態で固定化した層であり、且つ、前記ハードコート層がウレタン（メタ）アクリレート系樹脂を含むハードコート材料を硬化してなる層である、ものである。 That is, the optical film of the present invention is an optical film comprising a base material, a liquid crystal layer laminated on the base material, and a hard coat layer laminated on the liquid crystal layer,
The liquid crystal layer is a layer in which a liquid crystal material is fixed in a homeotropic alignment state, and the hard coat layer is a layer formed by curing a hard coat material containing a urethane (meth) acrylate resin. is there.
　上記本発明の光学フィルムにおいては、前記ハードコート層の厚みが０．１～５μｍであることが好ましい。 In the optical film of the present invention, the hard coat layer preferably has a thickness of 0.1 to 5 μm.
　また、上記本発明の光学フィルムにおいては、前記液晶材料がポリ（メタ）アクリレート系液晶ポリマーを含有することが好ましい。 In the optical film of the present invention, the liquid crystal material preferably contains a poly (meth) acrylate liquid crystal polymer.
　さらに、上記本発明の光学フィルムにおいては、前記基材が環状オレフィンポリマーからなることが好ましい。 Furthermore, in the optical film of the present invention, it is preferable that the substrate is made of a cyclic olefin polymer.
　本発明の偏光板は、上記本発明の光学フィルムを備えるものである。また、本発明の画像表示装置は、上記本発明の偏光板を備えるものである。 The polarizing plate of the present invention comprises the optical film of the present invention. Moreover, the image display apparatus of this invention is equipped with the polarizing plate of the said invention.
　また、本発明の光学フィルムの製造方法は、基材上に液晶材料をホメオトロピック配向の状態で固定化した液晶層を積層した後、前記液晶層上にウレタン（メタ）アクリレート系樹脂を含むハードコート材料を塗布し、硬化することによりハードコート層を積層し、
　前記基材と、前記基材上に積層された前記液晶層と、前記液晶層上に積層された前記ハードコート材料を硬化してなる前記ハードコート層とを備える光学フィルムを得る、方法である。 In the method for producing an optical film of the present invention, a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state is laminated on a base material, and then a hard material containing a urethane (meth) acrylate resin on the liquid crystal layer. A hard coat layer is laminated by applying and curing a coating material,
It is a method of obtaining an optical film provided with the substrate, the liquid crystal layer laminated on the substrate, and the hard coat layer formed by curing the hard coat material laminated on the liquid crystal layer. .
　本発明によれば、ホメオトロピック配向の液晶層とハードコート層との間の密着性を十分に高度なものとすることができ、十分に高度な耐傷性を有するとともに、十分に優れた耐熱性を有し、熱により液晶層の配向状態が変化することを十分に抑制することが可能な光学フィルム及びその製造方法を提供することが可能となる。 According to the present invention, the adhesion between the homeotropic alignment liquid crystal layer and the hard coat layer can be made sufficiently high, has sufficiently high scratch resistance, and sufficiently excellent heat resistance. It is possible to provide an optical film that can sufficiently suppress the change in the alignment state of the liquid crystal layer due to heat and a method for producing the same.
実施例１及び比較例１～２で得られた光学フィルムに関して、加熱時間（試験時間）と厚み方向の位相差（Ｒｔｈ）変化率との関係を示すグラフである。5 is a graph showing the relationship between the heating time (test time) and the thickness direction retardation (Rth) change rate for the optical films obtained in Example 1 and Comparative Examples 1 and 2.
　以下、本発明をその好適な実施形態に即して詳細に説明する。 Hereinafter, the present invention will be described in detail on the basis of preferred embodiments thereof.
　［光学フィルム］
　本発明の光学フィルムは、基材と、前記基材上に積層された液晶層と、前記液晶層上に積層されたハードコート層とを備える光学フィルムであって、
　前記液晶層が液晶材料をホメオトロピック配向の状態で固定化した層であり、且つ、前記ハードコート層がウレタン（メタ）アクリレート系樹脂を含むハードコート材料を硬化してなる層である、ものである。 [Optical film]
The optical film of the present invention is an optical film comprising a base material, a liquid crystal layer laminated on the base material, and a hard coat layer laminated on the liquid crystal layer,
The liquid crystal layer is a layer in which a liquid crystal material is fixed in a homeotropic alignment state, and the hard coat layer is a layer formed by curing a hard coat material containing a urethane (meth) acrylate resin. is there.
　〈基材〉
　本発明に用いられる基材は、光学フィルムに利用できるものであればよく、特に制限されず、公知の光学フィルム用の基材を適宜利用することができる。このような基材としては、例えば、有機高分子材料からなる基材、無機材料からなる基材（例えば、ガラス板、金属板、アルミニウム等の金属から形成されるフィルム等）を挙げることができる。 <Base material>
The base material used in the present invention is not particularly limited as long as it can be used for an optical film, and a known base material for an optical film can be appropriately used. Examples of such a base material include a base material made of an organic polymer material and a base material made of an inorganic material (for example, a glass plate, a metal plate, a film formed from a metal such as aluminum). .
　このような基材の中でも、コストや連続生産性の観点から、有機高分子材料からなる基材を用いることが好ましい。このような有機高分子材料としては、例えば、ポリビニルアルコール、ポリイミド、ポリフェニレンオキシド、ポリフェニレンスルフィド、ポリスルホン、ポリエーテルケトン、ポリエーテルエーテルケトン、ポリアリレート、ポリエチレンテレフタレートやポリエチレンナフタレート等のポリエステル系ポリマー；ジアセチルセルロースやトリアセチルセルロース等のセルロース系ポリマー；ポリカーボネート系ポリマー；ポリメチル（メタ）アクリレート等のアクリル系ポリマー等の透明ポリマー；ポリスチレン、アクリロニトリル・スチレン共重合体等のスチレン系ポリマー；ポリエチレン、ポリプロピレン、エチレン・プロピレン共重合体等のオレフィン系ポリマー；環状オレフィンポリマー（ポリシクロオレフィン）；塩化ビニル系ポリマー；ナイロンや芳香族ポリアミド等のアミド系ポリマー；等のポリマー材料及びこれらのブレンド物が挙げられる。なお、本発明においては、場合により「メタクリル」と「アクリル」とを総称して「（メタ）アクリル」と表記する。また、場合により「メタクリレート」と「アクリレート」とを総称して「（メタ）アクリレート」と表記する。 Among such substrates, it is preferable to use a substrate made of an organic polymer material from the viewpoint of cost and continuous productivity. Examples of such organic polymer materials include polyvinyl alcohol, polyimide, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyether ketone, polyether ether ketone, polyarylate, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; Cellulose polymers such as cellulose and triacetyl cellulose; polycarbonate polymers; transparent polymers such as acrylic polymers such as polymethyl (meth) acrylate; styrene polymers such as polystyrene and acrylonitrile / styrene copolymers; polyethylene, polypropylene, ethylene Olefin polymers such as propylene copolymer; Cyclic olefin polymer (polycycloolefin); Vinyl chloride Polymers; nylon and aromatic amide polymers such as polyamide; polymeric materials and blends of the like. In the present invention, “methacryl” and “acryl” are sometimes collectively referred to as “(meth) acryl” in some cases. In some cases, “methacrylate” and “acrylate” are collectively referred to as “(meth) acrylate”.
　また、このような有機高分子材料としては、光学フィルムに好適な特性（例えば透明性等）を示すことが可能となること等から、トリアセチルセルロース、ポリカーボネート、環状オレフィンポリマー（シクロオレフィンポリマー：ＣＯＰ）がより好ましく、環状オレフィンポリマーが特に好ましい。 In addition, as such an organic polymer material, it is possible to exhibit characteristics (for example, transparency) suitable for an optical film. Therefore, triacetyl cellulose, polycarbonate, cyclic olefin polymer (cycloolefin polymer: COP) ) Is more preferable, and a cyclic olefin polymer is particularly preferable.
　また、このような有機高分子材料からなる基材としては、透明性が高く、入手が容易であること等からは、トリアセチルセルロース、ポリカーボネート、環状オレフィンポリマー（シクロオレフィンポリマー：ＣＯＰ）からなるフィルム状の基材（プラスチックフィルム）が好ましい。また、このようなフィルム状の基材（プラスチックフィルム）の中でも、液晶材料がポリ（メタ）アクリレート系液晶ポリマーを含有する場合において、十分に高度な密着性を付与することができることからから、環状オレフィンポリマーからなるフィルム（以下、場合により「ＣＯＰフィルム」という。）が特に好ましい。ここで、「環状オレフィンポリマー（ＣＯＰ）」とは、ノルボルネン、ジシクロペンタジエン、テトラシクロドデセンやそれらの誘導体等の環状オレフィンから得られる樹脂の一般的な総称である。このような環状オレフィンポリマー（ＣＯＰ）としては、例えば、環状オレフィンの開環重合体、環状オレフィンの付加重合体、環状オレフィンとエチレン、プロピレン等のα－オレフィンとのランダム共重合体、これらを不飽和カルボン酸やその誘導体等で変性したグラフト変性体、これらの水素化物等が挙げられる。また、このような環状オレフィンとしては、ノルボルネン及びその誘導体、ジシクロペンタジエンが好ましい。 Moreover, as a base material made of such an organic polymer material, a film made of triacetyl cellulose, polycarbonate, a cyclic olefin polymer (cycloolefin polymer: COP) is highly transparent and easily available. A base material (plastic film) is preferred. In addition, among such film-like substrates (plastic films), when the liquid crystal material contains a poly (meth) acrylate-based liquid crystal polymer, a sufficiently high adhesion can be imparted, so A film made of an olefin polymer (hereinafter sometimes referred to as “COP film”) is particularly preferred. Here, the “cyclic olefin polymer (COP)” is a general generic name for resins obtained from cyclic olefins such as norbornene, dicyclopentadiene, tetracyclododecene and derivatives thereof. Examples of such a cyclic olefin polymer (COP) include a cyclic olefin ring-opening polymer, a cyclic olefin addition polymer, a random copolymer of a cyclic olefin and an α-olefin such as ethylene and propylene, and the like. Examples include graft-modified products modified with saturated carboxylic acid and derivatives thereof, and hydrides thereof. Moreover, as such a cyclic olefin, norbornene, its derivative (s), and dicyclopentadiene are preferable.
　また、このような基材としては、特に制限されないが、位相差機能を有するものが好ましく、位相差機能を有するＣＯＰフィルムであることがより好ましい。また、このような基材（特に好ましくはＣＯＰフィルム）は、一軸延伸したもの（いわゆる一軸延伸フィルム）であっても二軸延伸したもの（いわゆる二軸延伸フィルム）であってもよい。更に、このような一軸延伸フィルムを得る際に行う一軸延伸の方法としては、２つ以上のロールの周速差を利用した縦一軸延伸、または、前記基材（特に好ましくはＣＯＰフィルム）の両サイドを掴んで幅方向に延伸するテンター延伸を採用することが好ましい。また、このような基材は、これを縦方向および横方向に延伸することにより、二軸性の光学異方性を発現させて、光学異方性を有するフィルムとしてもよい。また、このような基材としては、Ｚ軸配向処理を施したものを用いてもよい。また、このような基材としては、その接着性を制御する目的で、片面もしくは両面にコロナ処理、プラズマ処理、ＵＶ－オゾン処理、ケン化処理等の表面処理を適宜行っても良い。 Further, such a substrate is not particularly limited, but preferably has a retardation function, and more preferably a COP film having a retardation function. Such a substrate (particularly preferably a COP film) may be a uniaxially stretched film (so-called uniaxially stretched film) or a biaxially stretched film (so-called biaxially stretched film). Furthermore, as a method of uniaxial stretching performed when obtaining such a uniaxially stretched film, longitudinal uniaxial stretching using a difference in peripheral speed between two or more rolls, or both of the base material (particularly preferably COP film) are used. It is preferable to employ tenter stretching that grips the side and stretches in the width direction. Moreover, such a base material is good also as a film which develops biaxial optical anisotropy by extending this to the vertical direction and a horizontal direction, and has optical anisotropy. Moreover, as such a base material, a substrate that has been subjected to a Z-axis alignment treatment may be used. In addition, such a substrate may be appropriately subjected to surface treatment such as corona treatment, plasma treatment, UV-ozone treatment, saponification treatment, etc. on one or both sides for the purpose of controlling the adhesion.
　また、このような基材としては、面内（フィルム状の場合、フィルム面内）のリターデーション値（以下、このような基材の面内リターデーション値は、場合により「Ｒｅ１」と省略して示す。）は、面内の主屈折率をｎｘ，ｎｙとし、厚さ方向の主屈折率をｎｚとし、厚さをｄ１（ｎｍ）とした場合に、計算式（Ａ）：
　　Ｒｅ１＝（ｎｘ－ｎｙ）×ｄ１［ｎｍ］　　　　　（Ａ）
で表される。このような基材（特に好ましくはＣＯＰフィルム）の面内のリターデーション値（Ｒｅ１）としては、画像表示装置（例えば液晶表示装置）の視角改良フィルムとして使用する場合等の用途の違いによっても最適な値が異なるばかりか、視角改良フィルムで使用する場合においても画像表示装置（例えば液晶表示装置）の方式や種々の光学パラメータに依存して最適な値が異なることから、一概には言えないが、例えば、５５０ｎｍの単色光に対しては、３０ｎｍ～５００ｎｍの範囲であることが好ましく、５０ｎｍ～４００ｎｍの範囲であることがより好ましい。 Further, as such a substrate, an in-plane retardation value (in the case of a film, in the film surface) (hereinafter, the in-plane retardation value of such a substrate is sometimes abbreviated as “Re1”. Is calculated using the formula (A) when the in-plane main refractive index is nx, ny, the main refractive index in the thickness direction is nz, and the thickness is d1 (nm):
Re1 = (nx−ny) × d1 [nm] (A)
It is represented by The in-plane retardation value (Re1) of such a substrate (particularly preferably a COP film) is also optimal depending on the application difference when used as a viewing angle improving film of an image display device (for example, a liquid crystal display device). However, the optimum values differ depending on the method of the image display device (for example, a liquid crystal display device) and various optical parameters even when used in a viewing angle improving film. For example, for monochromatic light of 550 nm, the range is preferably from 30 nm to 500 nm, and more preferably from 50 nm to 400 nm.
　また、このような基材（特に好ましくはＣＯＰフィルム）の厚さ方向のリターデーション値（以下、このような基材の厚さ方向のリターデーション値は、場合により「Ｒｔｈ１」と省略して示す。）は、面内の主屈折率をｎｘ，ｎｙとし、厚さ方向の主屈折率をｎｚとし、厚さをｄ１（ｎｍ）とした場合に、計算式（Ｂ）：
　　Ｒｔｈ１＝{（ｎｘ＋ｎｙ）／２－ｎｚ}×ｄ１［ｎｍ］　　　（Ｂ）
で表される。このようなＲｔｈ１の好適な値も一概に言えるものではないが、例えば、５５０ｎｍの単色光に対しては、０～３００ｎｍの範囲であることが好ましく、０～２００ｎｍの範囲であることがより好ましく、０～１５０ｎｍの範囲であることが更に好ましい。ＣＯＰフィルムの厚さは、１０～４００μｍであることが好ましく、１５～１００μｍであることが最も好ましい。 Further, the retardation value in the thickness direction of such a substrate (particularly preferably a COP film) (hereinafter, the retardation value in the thickness direction of such a substrate is sometimes abbreviated as “Rth1”). .) Is calculated when the in-plane main refractive index is nx, ny, the main refractive index in the thickness direction is nz, and the thickness is d1 (nm):
Rth1 = {(nx + ny) / 2−nz} × d1 [nm] (B)
It is represented by Although such a suitable value of Rth1 is not generally known, for example, for monochromatic light of 550 nm, a range of 0 to 300 nm is preferable, and a range of 0 to 200 nm is more preferable. More preferably, it is in the range of 0 to 150 nm. The thickness of the COP film is preferably 10 to 400 μm, and most preferably 15 to 100 μm.
　なお、このようなＲｅ１及びＲｔｈ１は、上記範囲内の値とすることにより、例えば、画像表示装置（例えば液晶表示装置）の視角改良フィルムとして用いる場合には、画像表示の色調補正を行いながら視野角を広げることが可能となり、画像表示装置の輝度向上フィルムとして用いる場合には、良好な輝度向上効果を得ることができる。他方、前記基材のＲｅ１値が３０ｎｍより小さい場合或いは５００ｎｍより大きい場合には、十分な視角改良効果が得られないか或いは斜めから見たときに不必要な色付きが生じる傾向にある。また、前記基材のＲｔｈ１が０ｎｍより小さい場合或いは３００ｎｍより大きい場合には、十分な視角改良効果が得られないか或いは斜めから見たときに不必要な色付きが生じる傾向がある。なお、二枚以上のフィルムを利用することで、基材全体としての光学的性質が前記の条件を満足するようにしてもよい。 It should be noted that such Re1 and Rth1 are set to values within the above range. For example, when used as a viewing angle improving film of an image display device (eg, a liquid crystal display device), the field of view is corrected while correcting the color tone of the image display. The corners can be widened, and when used as a brightness enhancement film for an image display device, a good brightness enhancement effect can be obtained. On the other hand, when the Re1 value of the substrate is smaller than 30 nm or larger than 500 nm, a sufficient viewing angle improving effect cannot be obtained, or unnecessary coloring tends to occur when viewed obliquely. When Rth1 of the substrate is smaller than 0 nm or larger than 300 nm, a sufficient viewing angle improving effect cannot be obtained or unnecessary coloring tends to occur when viewed from an oblique direction. In addition, you may make it the optical property as the whole base material satisfy the said conditions by utilizing two or more films.
　また、このような基材は市販品を適宜利用してもよく、例えば、基材としてＣＯＰフィルムを利用する場合、日本ゼオン株式会社製のゼオネックス、日本ゼオン株式会社製のゼオノア、ＪＳＲ株式会社製のアートン、積水化学株式会社製のエスシーナ、Topas　Advanced　Polymers　GmbH社製のTopas、三井化学株式会社製のアペル等を適宜利用することができる。 In addition, as such a base material, a commercially available product may be appropriately used. For example, when a COP film is used as the base material, ZEONEX manufactured by ZEON CORPORATION, ZEONOR manufactured by ZEON CORPORATION, manufactured by JSR Corporation Arton, Sessui Chemical Co., Ltd. Essina, Topas Advanced Polymers GmbH Topas, Mitsui Chemicals Co., Ltd. Appell, etc. can be used as appropriate.
　また、このような基材としては、液晶材料を安定してホメオトロピック配向状態とするために、表面上に配向膜が形成されている基材を用いてもよい。このような配向膜を形成するための材料（配向膜形成用材料）としては、公知の材料を適宜利用することができるが、例えば、ポリビニルアルコール（ＰＶＡ）、ポリビニルシンナメート、ポリビニルエーテル、ポリイミド、フッ素化ポリイミド等が挙げられる。 Further, as such a base material, a base material in which an alignment film is formed on the surface may be used in order to stably bring the liquid crystal material into a homeotropic alignment state. As a material for forming such an alignment film (alignment film forming material), a known material can be appropriately used. For example, polyvinyl alcohol (PVA), polyvinyl cinnamate, polyvinyl ether, polyimide, Examples include fluorinated polyimide.
　このような配向膜の形成工程は特に制限されず、公知の方法を適宜採用することができる。以下、かかる配向膜の形成工程として好適に採用することが可能な方法について簡単に説明する。このような配向膜を形成する際には、配向膜厚や表面特性をより容易に制御できることから、前記配向膜形成用材料を溶媒に溶解した溶液を調製し、その溶液を基材用のフィルム等（例えば、前述のＣＯＰフィルムのような基材として説明したもの等）の表面上に塗布することが好ましい。このような溶液は、前記配向膜形成用材料を溶解することができる溶媒を用いて適宜調製すればよい。例えば、前記配向膜形成用材料としてポリビニルアルコール（ＰＶＡ）を用いて、前記溶液としてＰＶＡの溶液を調製する場合、その溶媒としてはＰＶＡを溶解できる溶媒であればよいため、特に制限されるものではないが、例えば、水；メタノール、エタノール、イソプロピルアルコール等の低級アルコール；これらの混合物等を適宜使用できる。なお、このような配向膜形成用材料を溶媒中に溶解させる場合には、塗布工程や液晶材料の配向に影響を及ぼさない範囲において、配向膜に利用することが可能な各種の添加剤を適宜利用してもよい。また、前記配向膜形成用材料を溶媒中に溶解させる際には、溶解を促進するために加温を適宜施してもよい。 The formation process of such an alignment film is not particularly limited, and a known method can be appropriately employed. Hereinafter, a method that can be suitably employed as the alignment film forming step will be briefly described. When forming such an alignment film, since the alignment film thickness and surface characteristics can be controlled more easily, a solution in which the alignment film forming material is dissolved in a solvent is prepared, and the solution is used as a film for a substrate. Etc. (for example, what was demonstrated as a base material like the above-mentioned COP film etc.) is preferably applied. Such a solution may be appropriately prepared using a solvent capable of dissolving the alignment film forming material. For example, when polyvinyl alcohol (PVA) is used as the alignment film forming material and a PVA solution is prepared as the solution, the solvent is not particularly limited as long as it is a solvent capable of dissolving PVA. However, for example, water; lower alcohols such as methanol, ethanol, isopropyl alcohol; mixtures thereof can be used as appropriate. When such an alignment film forming material is dissolved in a solvent, various additives that can be used for the alignment film are appropriately selected within a range that does not affect the coating process and the alignment of the liquid crystal material. May be used. In addition, when the alignment film forming material is dissolved in a solvent, heating may be appropriately performed to promote dissolution.
　また、前記溶液を塗布する方法としては、特に制限されず、公知の方法を適宜利用することができ、例えば、大面積の配向膜を形成する場合においては、やわらかい樹脂板を用いるフレキソ印刷方式、ディスペンサー方式、グラビアコート方式、マイクログラビア方式、スクリーン印刷方式、リップコート方式、ダイコート方式等を採用した塗布方法を適宜利用することができる。このような塗布方法の中でも、グラビアコート方式、リップコート方式、ダイコート方式を採用した塗布方法が特に好ましい。 Further, the method for applying the solution is not particularly limited, and a known method can be used as appropriate. For example, in the case of forming a large-area alignment film, a flexographic printing method using a soft resin plate, A coating method employing a dispenser method, a gravure coating method, a micro gravure method, a screen printing method, a lip coating method, a die coating method, or the like can be used as appropriate. Among such coating methods, a coating method employing a gravure coating method, a lip coating method, or a die coating method is particularly preferable.
　このようにして、前記溶液を塗布した後においては、塗布により得られた塗膜（配向膜）を必要により乾燥させてもよい。このような乾燥工程における乾燥温度は、前記配向膜形成用材料の種類に応じて異なるものであり、基本的には、その材料自体の耐熱性（軟化点又はガラス転移点）の観点から、その材料自体の軟化点又はガラス転移点未満の温度とすることが望ましいが、目的によっては、軟化点又はガラス転移点以上の温度としてもよい。なお、前記配向膜形成用材料がＰＶＡの場合には、前記乾燥温度は、例えば、５０℃～１８０℃とすることが好ましく、８０℃～１６０℃とすることがより好ましい。また、このような乾燥の時間も特に制限はないが、１０秒～６０分とすることが好ましく、１分～３０分とすることがより好ましい。また、このような乾燥に乾燥装置を利用する場合においては、被乾燥膜と乾燥装置との相対的な移動速度を、相対風速が６０ｍ／分～１２００ｍ／分となるように制御することが好ましい。 Thus, after coating the solution, the coating film (alignment film) obtained by coating may be dried as necessary. The drying temperature in such a drying step varies depending on the type of the alignment film forming material, and basically, from the viewpoint of the heat resistance (softening point or glass transition point) of the material itself, Although it is desirable that the temperature be lower than the softening point or glass transition point of the material itself, depending on the purpose, the temperature may be higher than the softening point or glass transition point. When the alignment film forming material is PVA, the drying temperature is preferably 50 ° C. to 180 ° C., and more preferably 80 ° C. to 160 ° C., for example. The drying time is not particularly limited, but is preferably 10 seconds to 60 minutes, more preferably 1 minute to 30 minutes. Further, when using a drying apparatus for such drying, it is preferable to control the relative moving speed of the film to be dried and the drying apparatus so that the relative wind speed is 60 m / min to 1200 m / min. .
　なお、液晶の分野においては、配向の方向を制御するといった観点から、液晶層を形成するための基材に対して、布等で一定方向に擦るラビング処理を行うことが一般的である。一方、ホメオトロピック配向の液晶層に関して検討すると、ホメオトロピック配向は基本的に面内の異方性が生じない配向構造であるため、ラビング処理は必ずしも必要な処理ではない。そのため、前記基材上に積層する液晶層が、液晶材料をホメオトロピック配向の状態で固定化した層（ホメオトロピック配向液晶層）である本発明の光学フィルムにおいては、前記基材にラビング処理を施すことは必ずしも必要ではない。しかしながら、液晶材料を塗布した場合（特に前述のような配向膜上に塗布した場合）のはじきを抑制するといった観点からは、前記基材に対して弱いラビング処理を施すことが好ましい。また、このような弱いラビング処理としては、ラビング布をロールに巻きつけて回転させつつ、かかるロールに基材が接触するようにして基材を移動させて、基材の表面をラビング布で擦る方法を採用することが好ましい。なお、このような方法を採用する場合、布の移動速度（回転速度）と基材の移動速度の比（周速比）は、５０以下とすることが好ましく、２５以下とすることがより好ましく、１０以下でとすることが更に好ましい。周速比が５０より大きい場合、ラビングの効果が強すぎて液晶材料が完全に垂直に配向しきれず、垂直方向より面内方向に倒れた配向となる場合が生じる傾向にある。 In the field of liquid crystals, from the viewpoint of controlling the direction of alignment, it is common to perform a rubbing process in which a substrate for forming a liquid crystal layer is rubbed in a certain direction with a cloth or the like. On the other hand, when examining the liquid crystal layer having homeotropic alignment, the homeotropic alignment is basically an alignment structure in which in-plane anisotropy does not occur, and thus the rubbing process is not necessarily a necessary process. Therefore, in the optical film of the present invention in which the liquid crystal layer laminated on the substrate is a layer (homeotropic alignment liquid crystal layer) in which a liquid crystal material is fixed in a homeotropic alignment state, the substrate is rubbed. It is not always necessary to apply it. However, from the viewpoint of suppressing repelling when a liquid crystal material is applied (particularly when it is applied on the alignment film as described above), it is preferable to subject the substrate to a weak rubbing treatment. Further, as such a weak rubbing treatment, the base material is moved so that the base material comes into contact with the roll while the rubbing cloth is wound around the roll, and the surface of the base material is rubbed with the rubbing cloth. It is preferable to adopt the method. When such a method is employed, the ratio of the cloth movement speed (rotational speed) to the substrate movement speed (circumferential speed ratio) is preferably 50 or less, more preferably 25 or less. More preferably, it is 10 or less. When the peripheral speed ratio is greater than 50, the rubbing effect is too strong, and the liquid crystal material cannot be perfectly aligned vertically, and tends to be inclined in the in-plane direction from the vertical direction.
　〈液晶層〉
　本発明においては、前記基材上に液晶層が積層されている。このような液晶層は、液晶材料をホメオトロピック配向の状態で固定化した層（ホメオトロピック配向液晶層）である。 <Liquid crystal layer>
In the present invention, a liquid crystal layer is laminated on the substrate. Such a liquid crystal layer is a layer (homeotropic alignment liquid crystal layer) in which a liquid crystal material is fixed in a homeotropic alignment state.
　このような液晶層の材料である液晶材料は、基板上においてホメオトロピック配向させて、その配向状態を固定化し得る液晶性化合物を含有する材料であればよく、特に制限されるものではない。このような液晶性化合物としては、例えば、低分子液晶化合物（重合性基を有する液晶性モノマー）や液晶性高分子化合物、それらの混合物を適宜利用することができる。 The liquid crystal material that is a material for such a liquid crystal layer is not particularly limited as long as it is a material containing a liquid crystalline compound that can be homeotropically aligned on the substrate to fix the alignment state. As such a liquid crystal compound, for example, a low molecular liquid crystal compound (a liquid crystal monomer having a polymerizable group), a liquid crystal polymer compound, or a mixture thereof can be appropriately used.
　このような液晶性化合物として用いることが可能な低分子液晶化合物（重合性基を有する液晶性モノマー）としては、配向を容易に固定化できるといった観点から、光や熱により反応する重合性基を備える化合物が好ましい。このような重合性基としては、ビニル基、アクリロイル基、ビニルオキシ基、オキシラニル基、オキセタニル基、アジリジニル基等が好ましい。なお、このような重合性基としては、反応条件等によっては、例えば、イソシアナート基、水酸基、アミノ基、酸無水物基、カルボキシル基等の他の重合性基を使用してもよい。 As a low-molecular liquid crystal compound (liquid crystalline monomer having a polymerizable group) that can be used as such a liquid crystalline compound, a polymerizable group that reacts with light or heat is used from the viewpoint that alignment can be easily fixed. The compound provided is preferred. As such a polymerizable group, a vinyl group, acryloyl group, vinyloxy group, oxiranyl group, oxetanyl group, aziridinyl group and the like are preferable. As such a polymerizable group, other polymerizable groups such as an isocyanate group, a hydroxyl group, an amino group, an acid anhydride group, and a carboxyl group may be used depending on the reaction conditions.
　また、このような液晶性化合物として用いることが可能な液晶性高分子化合物としては、主鎖型液晶性ポリマーや側鎖型液晶性ポリマー等が挙げられる。このような主鎖型液晶性ポリマーとしては、例えば、ポリエステル系液晶ポリマー、ポリエステルアミド系液晶ポリマー、ポリアミド系液晶ポリマー、ポリアミドイミド系液晶ポリマー、ポリカーボネート系液晶ポリマー等を挙げることができる。また、前記側鎖型液晶性ポリマーとしては、例えば、ポリ（メタ）アクリレート系液晶ポリマー、ポリマロネート系液晶ポリマー、ポリエーテル系液晶ポリマー、ポリシロキサン系液晶ポリマー等を挙げることができる。 Further, examples of the liquid crystalline polymer compound that can be used as such a liquid crystalline compound include main chain liquid crystalline polymers and side chain liquid crystalline polymers. Examples of such main chain liquid crystalline polymers include polyester liquid crystal polymers, polyester amide liquid crystal polymers, polyamide liquid crystal polymers, polyamide imide liquid crystal polymers, and polycarbonate liquid crystal polymers. Examples of the side chain liquid crystal polymer include poly (meth) acrylate liquid crystal polymer, polymalonate liquid crystal polymer, polyether liquid crystal polymer, and polysiloxane liquid crystal polymer.
　このような液晶性化合物の中でも、低温の配向条件であっても良好な配向性を有することが望ましいといった観点から、前記側鎖型液晶性ポリマーがより好ましく、ポリ（メタ）アクリレート系液晶ポリマーがより好ましい。また、このようなポリ（メタ）アクリレート系液晶ポリマーとしては、液晶性を示す化学構造を有するだけではなく、配向後の液晶構造をより効率よく固定化するために、重合基を有することが望まれることから、下記一般式（１）で表わされるポリ（メタ）アクリレート系液晶ポリマー（下記一般式（１）中に示す各繰り返し単位を後述のａ～ｆで表わされるモル比の条件を満たすようにして含有するポリ（メタ）アクリレート系の液晶ポリマー）が好ましい。 Among these liquid crystalline compounds, the side chain liquid crystalline polymer is more preferable from the viewpoint that it is desirable to have good alignment even under low temperature alignment conditions, and a poly (meth) acrylate liquid crystal polymer is more preferable. More preferred. Further, such a poly (meth) acrylate-based liquid crystal polymer not only has a chemical structure exhibiting liquid crystallinity, but also desirably has a polymerization group in order to more efficiently fix the aligned liquid crystal structure. Therefore, a poly (meth) acrylate liquid crystal polymer represented by the following general formula (1) (respectively repeating units shown in the following general formula (1) should satisfy the conditions of the molar ratio represented by a to f described later. (Poly (meth) acrylate-based liquid crystal polymer) contained in the form of
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　なお、上記一般式（１）中、Ｒ１は、それぞれ独立に、水素又はメチル基を表し、Ｒ２は、それぞれ独立に、水素、メチル基、エチル基、ブチル基、ヘキシル基、オクチル基、ノニル基、デシル基、ドデシル基、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基、ペンチルオキシ基、ヘキシルオキシ基、ヘプチルオキシ基、オクチルオキシ基、デシルオキシ基、ドデシルオキシ基、シアノ基、ブロモ基、クロロ基、フルオロ基又はカルボキシル基を表し、Ｒ３は、それぞれ独立に、水素、メチル基又はエチル基を表し、Ｒ４は、炭素数１～２４の炭化水素基を表し、Ｌ１は、それぞれ独立に、単結合、－Ｏ－、－Ｏ－ＣＯ－、－ＣＯ－Ｏ－、－ＣＨ＝ＣＨ－又は－Ｃ≡Ｃ－を表し、ｐは、１から１０までの整数を表し、ｑは０から１０までの整数を表し、ａ、ｂ、ｃ、ｄ、ｅ及びｆは、それぞれ、ポリマー中の各繰り返し単位（各ユニット）のモル比であって、ａ～ｆの和（ａ＋ｂ＋ｃ＋ｄ＋ｅ＋ｆ）が１．０となり且つｃとｄとｅの和（ｃ＋ｄ＋ｅ）が０とはならない（ｃ～ｅのうちの少なくとも１つが正の値をとる）という条件を満たす（なお、モル比の計算に際しては、Ｒ１～Ｒ４で表される置換基のみが異なる繰り返し単位（同じ一般式で表すことができる繰り返し単位）は同じ繰り返し単位（ユニット）と判断する。なお、ａ～ｆの値は、前記一般式（１）中に表わされる各繰り返し単位を、上記ａ～ｆの比率で含むポリマーが液晶性を示すように選択される必要がある。）。なお、Ｌ１が単結合とは、Ｌ１を介して結合している基が直接結合することを意味し、例えば式：Ａ－Ｌ１－Ｂで表される化合物があると仮定した場合にＬ１が単結合であるとは前記化合物が式：Ａ－Ｂで表される化合物であることを意味する。 In the general formula (1), each R 1 independently represents hydrogen or a methyl group, and each R 2 independently represents hydrogen, a methyl group, an ethyl group, a butyl group, a hexyl group, an octyl group, Nonyl group, decyl group, dodecyl group, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group, cyano group, bromo group, Represents a chloro group, a fluoro group or a carboxyl group, each R 3 independently represents hydrogen, a methyl group or an ethyl group, R 4 represents a hydrocarbon group having 1 to 24 carbon atoms, and L 1 represents Independently, it represents a single bond, —O—, —O—CO—, —CO—O—, —CH═CH— or —C≡C—, p represents an integer of 1 to 10, and q represents 0 to 1 A, b, c, d, e, and f are the molar ratios of each repeating unit (each unit) in the polymer, and the sum of (a + b + c + d + e + f) is 1.0. And the sum of c, d, and e (c + d + e) does not become 0 (at least one of c to e takes a positive value) (in calculating the molar ratio, R 1 to Repeating units (repeating units that can be represented by the same general formula) that differ only in the substituent represented by R 4 are determined to be the same repeating units (units), and the values of a to f are the same as those in the general formula (1). It is necessary to select a polymer containing each of the repeating units represented in the above ratios a to f so as to exhibit liquid crystallinity). Note that L 1 is a single bond means that a group bonded through L 1 is directly bonded. For example, when it is assumed that there is a compound represented by the formula: AL 1 -B L 1 is a single bond means that the compound is a compound represented by the formula AB.
　また、上記一般式（１）中においてａ～ｆで表わされるモル比は、それぞれ、以下に示すａ～ｆの数値範囲内の値であることが好ましい。 In the general formula (1), the molar ratios represented by a to f are preferably values within the numerical ranges of a to f shown below.
　ａ：好ましくは０～０．８０、より好ましくは０．０５～０．５０
　ｂ：好ましくは０～０．９０、より好ましくは０．１０～０．７０
　ｃ：好ましくは０～０．５０、より好ましくは０．１０～０．３０
　ｄ：好ましくは０～０．５０、より好ましくは０．１０～０．３０
　ｅ：好ましくは０～０．５０、より好ましくは０．１０～０．３０
　ｆ：好ましくは０～０．３０、より好ましくは０．０１～０．１０
　また、Ｒ２は、好ましくは、水素、メチル基、ブチル基、メトキシ基、シアノ基、ブロモ基、フルオロ基であり、特に好ましくは、水素、メトキシ基、またはシアノ基である。また、Ｌ１は、好ましくは、単結合、－Ｏ－、－Ｏ－ＣＯ－又は－ＣＯ－Ｏ－である。さらに、Ｒ４は、好ましくは、炭素数２、３、４、６、８または１８の炭化水素基である。 a: Preferably 0 to 0.80, more preferably 0.05 to 0.50
b: preferably 0 to 0.90, more preferably 0.10 to 0.70
c: preferably 0 to 0.50, more preferably 0.10 to 0.30
d: preferably 0 to 0.50, more preferably 0.10 to 0.30
e: preferably 0 to 0.50, more preferably 0.10 to 0.30
f: preferably 0 to 0.30, more preferably 0.01 to 0.10
R 2 is preferably hydrogen, methyl group, butyl group, methoxy group, cyano group, bromo group, or fluoro group, and particularly preferably hydrogen, methoxy group, or cyano group. L 1 is preferably a single bond, —O—, —O—CO— or —CO—O—. R 4 is preferably a hydrocarbon group having 2, 3, 4 , 6, 8 or 18 carbon atoms.
　なお、このような一般式（１）で表わされるポリ（メタ）アクリレート系液晶ポリマーは、その効果を損なわない範囲において、前記一般式（１）中の繰り返し単位以外の他の繰り返し単位を含んでいてもよく、その場合には、前記一般式（１）中の繰り返し単位の総量に対する他の繰り返し単位の含有量のモル比（［前記一般式（１）中の繰り返し単位の総量］：［他の繰り返し単位の含有量］）が９９：１～８０：２０であることが好ましく、９５：５～８５：１５であることがより好ましい。 The poly (meth) acrylate-based liquid crystal polymer represented by the general formula (1) includes a repeating unit other than the repeating unit in the general formula (1) as long as the effect is not impaired. In that case, the molar ratio of the content of other repeating units to the total amount of repeating units in the general formula (1) ([total amount of repeating units in the general formula (1)]: [others] The content of the repeating unit] is preferably 99: 1 to 80:20, more preferably 95: 5 to 85:15.
　また、このような液晶性化合物として好適な側鎖型液晶性ポリマーは、重量平均分子量が１０００～２０００００であるものが好ましく、３０００～５００００のものが特に好ましい。このような重量平均分子量が前記範囲外の値となる場合には、液晶層の強度が不足したり、配向性が低下する傾向にある。このような重量平均分子量は、測定装置として東ソー製高速ＧＰＣ装置ＥｃｏＳｅｃ　ＨＬＣ－８３２０ＧＰＣを使用し、カラムとしてＴＳＫｇｅｌＳｕｐｅｒＨ４０００、ＴＳＫｇｅｌＳｕｐｅｒＨ１０００、ＴＳＫｇｅｌＳｕｐｅｒＭＰ（ＨＺ）－Ｈ、ＴＳＫｇｅｌＭｕｌｔｉｐｏｒｅＨＺ－Ｈを使用し、測定条件として、カラムオーブン温度：４０℃、分離溶媒：テトラヒドロフラン、流速：０．３５ｍｌ／ｍｉｎといった条件を採用したＧＰＣ測定により得られたデータに基いて、ポリスチレン換算の重量平均分子量として求められる値を採用する。なお、このような液晶性化合物としては１種を単独で用いてもよく、あるいは、２種以上を混合して利用してもよい。 Further, the side chain type liquid crystalline polymer suitable as such a liquid crystalline compound preferably has a weight average molecular weight of 1,000 to 200,000, particularly preferably 3,000 to 50,000. When such a weight average molecular weight becomes a value outside the above range, the strength of the liquid crystal layer tends to be insufficient or the orientation tends to decrease. For such weight average molecular weight, Tosoh's high-speed GPC device EcoSec HLC-8320GPC is used as a measuring device, TSKgelSuperH4000, TSKgelSuperH1000, TSKgelSuperMP (HZ) -H, TSKgelMultiporeHZ-H are used as measuring conditions, and column. Based on data obtained by GPC measurement employing conditions such as temperature: 40 ° C., separation solvent: tetrahydrofuran, flow rate: 0.35 ml / min, a value obtained as a weight average molecular weight in terms of polystyrene is adopted. In addition, as such a liquid crystalline compound, 1 type may be used independently, or 2 or more types may be mixed and utilized.
　また、このような液晶性化合物としては、固定化を行う際にカチオン重合性基を利用して重合させた場合に、得られる液晶層の耐熱性がより向上するという観点から、カチオン重合性基を含有するものがより好ましい。このようなカチオン重合性基としては、エポキシ基、オキセタニル基、ビニルオキシ基が好ましく、オキセタニル基がより好ましい。なお、このようなカチオン重合性基を含有する液晶性化合物としても、上記一般式（１）で表わされるポリ（メタ）アクリレート系液晶ポリマーは好適に利用することができる。 In addition, such a liquid crystalline compound includes a cationic polymerizable group from the viewpoint of further improving the heat resistance of the obtained liquid crystal layer when it is polymerized using a cationic polymerizable group during immobilization. More preferably, it contains As such a cationically polymerizable group, an epoxy group, an oxetanyl group, and a vinyloxy group are preferable, and an oxetanyl group is more preferable. In addition, also as a liquid crystalline compound containing such a cationically polymerizable group, the poly (meth) acrylate liquid crystal polymer represented by the general formula (1) can be suitably used.
　なお、このような液晶性化合物の合成法は特に制限されるものではなく、公知の方法（例えば通常の有機化学の合成法で用いられる方法）を適用することによって適宜合成することができる。例えば、上記一般式（１）で表わされるポリ（メタ）アクリレート系液晶ポリマーは、式（１）中の繰り返し単位を形成させることが可能な（メタ）アクリル化合物（例えば、式（１）中の繰り返し単位を形成させることが可能な（メタ）アクリル酸）をそれぞれ準備し、各（メタ）アクリル化合物中の（メタ）アクリル基をラジカル重合又はアニオン重合により共重合することにより容易に合成することができる。また、このような重合の条件は特に限定されるものではなく、公知の条件を適宜採用することができる。また、このような液晶性化合物としては、市販のものを適宜利用してもよい。 In addition, the synthesis method of such a liquid crystalline compound is not particularly limited, and can be appropriately synthesized by applying a known method (for example, a method used in a general organic chemistry synthesis method). For example, the poly (meth) acrylate-based liquid crystal polymer represented by the general formula (1) is a (meth) acrylic compound (for example, in the formula (1) that can form a repeating unit in the formula (1). Prepare (meth) acrylic acid capable of forming repeating units) and synthesize easily by copolymerizing (meth) acrylic groups in each (meth) acrylic compound by radical polymerization or anionic polymerization Can do. Moreover, the conditions for such polymerization are not particularly limited, and known conditions can be appropriately employed. Moreover, as such a liquid crystalline compound, a commercially available product may be appropriately used.
　また、前記液晶材料としては、前記液晶性化合物のみを用いてもよいが、基材との密着性をより向上させることができるという観点から、前記液晶性化合物と共にオキセタン基を有する（メタ）アクリル化合物を含有するものを利用すること（前記液晶材料をオキセタン基を有する（メタ）アクリル化合物を前記液晶性化合物と共に含有する液晶性組成物として利用すること）が好ましい。このように、前記液晶材料に、オキセタン基を有する（メタ）アクリル化合物を含有した場合には、基材として難接着性材料からなる基材（例えばＣＯＰフィルム）を用いる場合においても、かかる基材と液晶層との間において十分に高度な密着力が得られ、基材と液晶層との密着性が大幅に向上する傾向にある。すなわち、前記液晶材料にオキセタン基を有する（メタ）アクリル化合物を含有した場合には、それを含有しなかった場合と比較して、難接着性材料からなる基材（例えばＣＯＰフィルム）と液晶層との間に、より十分な密着力を付与することができる傾向にある。このように、前記オキセタン基を有する（メタ）アクリル化合物により基材と液晶層との密着性が向上する理由は必ずしも明らかではないが、オキセタン基を有する（メタ）アクリル化合物によって、難接着性材料からなる基材（例えばＣＯＰフィルム）と、その基材に対する親和性が十分ではない液晶性化合物との間の密着に何らかの仲介作用が得られるためであると本発明者らは推察する。なお、本発明においては、前記オキセタン基を有する（メタ）アクリル化合物のうちの液晶性を示す化合物を単独で前記液晶性化合物として前記液晶材料に利用する場合（他の液晶性の化合物を利用しない場合）を除いて、前記液晶性化合物は、前記オキセタン基を有する（メタ）アクリル化合物以外の液晶性の化合物をいう。 In addition, as the liquid crystal material, only the liquid crystal compound may be used, but from the viewpoint that adhesion with a substrate can be further improved, a (meth) acryl having an oxetane group together with the liquid crystal compound. It is preferable to use a compound containing a compound (using the liquid crystal material as a liquid crystalline composition containing a (meth) acrylic compound having an oxetane group together with the liquid crystalline compound). As described above, when the liquid crystal material contains a (meth) acrylic compound having an oxetane group, such a base material is used even when a base material (for example, a COP film) made of a hardly adhesive material is used as the base material. A sufficiently high adhesive force is obtained between the liquid crystal layer and the liquid crystal layer, and the adhesiveness between the substrate and the liquid crystal layer tends to be greatly improved. That is, when the (meth) acrylic compound having an oxetane group is contained in the liquid crystal material, a substrate (for example, a COP film) and a liquid crystal layer made of a hardly-adhesive material are compared with the case where it is not contained. Between the two, there is a tendency that more sufficient adhesion can be imparted. As described above, the reason why the adhesion between the substrate and the liquid crystal layer is improved by the (meth) acrylic compound having the oxetane group is not necessarily clear, but the (meth) acrylic compound having the oxetane group is difficult to adhere to. The present inventors infer that this is because some kind of mediating action is obtained in the adhesion between the substrate (for example, a COP film) made of the liquid crystal and the liquid crystal compound having insufficient affinity for the substrate. In the present invention, among the (meth) acrylic compounds having an oxetane group, a compound exhibiting liquid crystallinity is used alone as the liquid crystal compound in the liquid crystal material (no other liquid crystal compound is used). The liquid crystalline compound means a liquid crystalline compound other than the (meth) acrylic compound having the oxetane group.
　このようなオキセタン基を有する（メタ）アクリル化合物としては、下記一般式（２）～（４）で表される化合物のうちの少なくとも１種が好ましい。 As the (meth) acrylic compound having such an oxetane group, at least one of the compounds represented by the following general formulas (2) to (4) is preferable.
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
　上記一般式（２）～（４）において、Ｒ５は、それぞれ独立に、水素またはメチル基を表し、Ｒ６は、それぞれ独立に、水素、メチル基又はエチル基を表し、Ｌ２は、それぞれ独立に、単結合、－Ｏ－、－Ｏ－ＣＯ－又は－ＣＯ－Ｏ－を表し、ｍは、それぞれ独立に、１から１０までの整数であり、ｎは、それぞれ独立に、０から１０までの整数である。なお、Ｌ２が単結合とは、Ｌ２を介して結合している基が直接結合することを意味し、例えば式：Ａ－Ｌ２－Ｂで表される化合物があると仮定した場合にＬ２が単結合であるとは前記化合物が式：Ａ－Ｂで表される化合物であることを意味する。 In the general formulas (2) to (4), each R 5 independently represents hydrogen or a methyl group, each R 6 independently represents hydrogen, a methyl group or an ethyl group, and each of L 2 represents Independently represents a single bond, —O—, —O—CO— or —CO—O—, wherein m is each independently an integer from 1 to 10, and n is each independently 0 to 10 It is an integer up to. The term “L 2 is a single bond” means that a group bonded via L 2 is directly bonded. For example, when it is assumed that there is a compound represented by the formula: AL 2 —B L 2 is a single bond means that the compound is a compound represented by the formula AB.
　このようなオキセタン基を有する（メタ）アクリル化合物は必ずしも液晶性を示す必要はない。また、オキセタン基を有する（メタ）アクリル化合物としては、上記一般式（２）～（４）で表わされる化合物の１種を単独で用いてもよく、あるいは、上記一般式（２）～（４）で表わされる化合物の２種以上を混合して混合物として用いてもよい。このような一般式（２）～（４）で表わされる化合物としては、特に制限されるものではないが、下記化合物をその好適な例として挙げることができる。 Such a (meth) acrylic compound having an oxetane group is not necessarily required to exhibit liquid crystallinity. As the (meth) acrylic compound having an oxetane group, one of the compounds represented by the above general formulas (2) to (4) may be used alone, or the above general formulas (2) to (4) may be used. Or a mixture of two or more of the compounds represented by formula (1). The compounds represented by the general formulas (2) to (4) are not particularly limited, but preferred examples thereof include the following compounds.
Figure JPOXMLDOC01-appb-C000003
Figure JPOXMLDOC01-appb-C000003
　また、このようなオキセタン基を有する（メタ）アクリル化合物の合成法は特に制限されるものではなく、公知の方法（例えば通常の有機化学の合成法で用いられる方法）を適用することによって適宜合成することができる。例えば、ウィリアムソンのエーテル合成や、縮合剤を用いたエステル合成などの手段で、オキセタン基を持つ部位と（メタ）アクリル基を持つ部位をつなげることで、オキセタン基と（メタ）アクリル基との全く異なる２つの反応性基を持つオキセタン基を有する（メタ）アクリル化合物を合成することができる。このような合成にあたっては、オキセタン基がカチオン重合性を有するため、強い酸性条件下では、重合や開環などの副反応を起こすことを考慮して反応条件を選ぶ必要がある。 In addition, the method for synthesizing such a (meth) acrylic compound having an oxetane group is not particularly limited, and is appropriately synthesized by applying a known method (for example, a method used in ordinary organic chemistry synthesis methods). can do. For example, by connecting a part having an oxetane group and a part having a (meth) acrylic group by means of Williamson's ether synthesis or ester synthesis using a condensing agent, the oxetane group and the (meth) acrylic group A (meth) acrylic compound having an oxetane group having two completely different reactive groups can be synthesized. In such synthesis, since the oxetane group has cationic polymerizability, it is necessary to select reaction conditions in consideration of causing side reactions such as polymerization and ring opening under strong acidic conditions.
　また、前記液晶材料には、前記液晶性化合物と共に下記一般式（５）で表されるジオキセタン化合物を更に含有させてもよい。なお、本発明においては、前記ジオキセタン化合物のうちの液晶性を示す化合物を単独で前記液晶性化合物として前記液晶材料に利用する場合（他の液晶性の化合物を利用しない場合）を除いて、前記液晶性化合物は、前記ジオキセタン化合物以外の液晶性の化合物をいう。また、下記一般式（５）で表されるジオキセタン化合物は、液晶性の有無を問わず使用できるが、ジオキセタン化合物を含有させることによる液晶性の低下を防止するといった観点からは、液晶性を示すものが好ましい。 The liquid crystal material may further contain a dioxetane compound represented by the following general formula (5) together with the liquid crystal compound. In the present invention, except for the case where a liquid crystal compound among the dioxetane compounds is used as the liquid crystal material alone as the liquid crystal compound (when no other liquid crystal compound is used), The liquid crystal compound refers to a liquid crystal compound other than the dioxetane compound. In addition, the dioxetane compound represented by the following general formula (5) can be used regardless of the presence or absence of liquid crystallinity, but exhibits liquid crystallinity from the viewpoint of preventing a decrease in liquid crystallinity due to the inclusion of the dioxetane compound. Those are preferred.
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000004
　上記一般式（５）において、Ｒ７は、それぞれ独立に、水素、メチル基またはエチル基を表し、Ｌ３は、それぞれ独立に、単結合または－（ＣＨ２）ｎ－（ｎは１～１２の整数）を表し、Ｘ１は、それぞれ独立に、単結合、－Ｏ－、－Ｏ－ＣＯ－または－ＣＯ－Ｏ－を表し、Ｍ１は、下記一般式（６）または下記一般式（７）で表されるいずれかであり、下記一般式（６）および下記一般式（７）中のＰ１は、それぞれ独立に下記一般式（８）から選ばれる基を表し、Ｐ２は下記一般式（９）から選ばれる基を表し、Ｌ４は、それぞれ独立に単結合、－ＣＨ＝ＣＨ－、－Ｃ≡Ｃ－、－Ｏ－、－Ｏ－ＣＯ－または－ＣＯ－Ｏ－を表す。 In the general formula (5), each R 7 independently represents hydrogen, a methyl group or an ethyl group, and each L 3 independently represents a single bond or — (CH 2 ) n — (n is 1 to 12). X 1 represents each independently a single bond, —O—, —O—CO— or —CO—O—, and M 1 represents the following general formula (6) or the following general formula ( 7) is any one represented by, P 1 in the following general formula (6) and the following general formula (7) represents each independently a group selected from the following general formula (8), P 2 is below L 4 represents a group selected from general formula (9), and each L 4 independently represents a single bond, —CH═CH—, —C≡C—, —O—, —O—CO— or —CO—O—. To express.
　　－Ｐ１－Ｌ４－Ｐ２－Ｌ４－Ｐ１－　　　（６）
　　－Ｐ１－Ｌ４－Ｐ１－　　　（７） -P 1 -L 4 -P 2 -L 4 -P 1- (6)
-P 1 -L 4 -P 1- (7)
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000006
　上記一般式（８）及び（９）中、Ｅｔ、ｉＰｒ、ｎＢｕ及びｔＢｕは、それぞれエチル基、イソプロピル基、ノルマルブチル基及びターシャリーブチル基を表す。 In the general formulas (8) and (9), Et, iPr, nBu, and tBu represent an ethyl group, an isopropyl group, a normal butyl group, and a tertiary butyl group, respectively.
　上記一般式（５）において、Ｍ１基から見て左右のオキセタン基を結合している連結基は同一（対称型）であっても異なっていても（非対称型）よく、液晶性は構造により異なるが示さなくともよい。また、上記一般式（５）で表される化合物は、Ｌ３、Ｘ１およびＭ１の組み合わせから多くの化合物が例示されるが、好ましくは下記の化合物を挙げることができる。 In the general formula (5), the linking groups connecting the left and right oxetane groups as viewed from the M 1 group may be the same (symmetrical) or different (asymmetrical), and the liquid crystallinity depends on the structure. It is different but not necessary. The compound represented by the general formula (5) is a number of compounds from a combination of L 3, X 1 and M 1 are exemplified, preferably may be mentioned the following compounds.
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000007
　上記一般式（５）で表されるジオキセタン化合物は有機化学における通常の合成方法に従って合成することができ、合成方法は特に限定されるものではない。 The dioxetane compound represented by the general formula (5) can be synthesized according to a usual synthesis method in organic chemistry, and the synthesis method is not particularly limited.
　また、前記液晶材料として、前記液晶性化合物と共に前記オキセタン基を有する（メタ）アクリル化合物や前記ジオキセタン化合物を用いる場合（前記液晶材料を液晶性組成物として用いる場合）、そのような液晶性組成物中の前記液晶性化合物、前記オキセタン基を有する（メタ）アクリル化合物、前記ジオキセタン化合物の含有比は、質量比（［前記オキセタン基を有する化合物］：［前記液晶性化合物］：［前記ジオキセタン化合物］）で１～３０：１００：０～４０となる範囲であることが好ましく、３～２０：１００：０～３０となる範囲であることがより好ましい。このような質量比が前記数値範囲外では、ホメオトロピック配向保持能が十分なものとならなくなる傾向にあるばかりか、難接着性材料からなる基材（特にＣＯＰフィルム）と液晶層の層間密着力が優れた液晶フィルムを得ることが困難となる傾向にある。 Moreover, when using the (meth) acrylic compound and the dioxetane compound which have the said oxetane group with the said liquid crystalline compound as the said liquid crystalline material (when using the said liquid crystalline material as a liquid crystalline composition), such a liquid crystalline composition The content ratio of the liquid crystalline compound, the (meth) acrylic compound having the oxetane group, and the dioxetane compound in a mass ratio ([the compound having the oxetane group]: [the liquid crystalline compound]: [the dioxetane compound] ) Is preferably in the range of 1 to 30: 100: 0 to 40, and more preferably in the range of 3 to 20: 100: 0 to 30. When such a mass ratio is outside the above numerical range, the homeotropic orientation retention ability tends not to be sufficient, and the interlayer adhesion between the base material (particularly COP film) made of a difficult-to-adhere material and the liquid crystal layer. However, it tends to be difficult to obtain an excellent liquid crystal film.
　また、このような液晶材料により形成される液晶層中の液晶性化合物自体の含有量が、７０～９５質量％であることが好ましく、７５～９５質量％であることがより好ましい。このような液晶性化合物の含有量が前記下限未満では充分な位相差を示さない傾向にあり、他方、前記上限を超えると配向性が低下する傾向にある。 Further, the content of the liquid crystal compound itself in the liquid crystal layer formed of such a liquid crystal material is preferably 70 to 95% by mass, and more preferably 75 to 95% by mass. If the content of such a liquid crystal compound is less than the lower limit, there is a tendency that a sufficient retardation is not exhibited. On the other hand, if the content exceeds the upper limit, the orientation tends to be lowered.
　また、このような液晶材料としては、液晶材料の固定化をカチオン重合により行う場合（例えば、前述のように、前記液晶性化合物としてカチオン重合性基を有する液晶性化合物を利用（含有）する場合）、カチオン重合をより容易に速やかに進行させるといった観点からは、前記液晶材料中に、光や熱等の外部刺激によりカチオンを発生する光カチオン発生剤及び／又は熱カチオン発生剤（場合により、これらを「カチオン発生剤」と総称します。）を含有させることが好ましい。また、前記カチオン発生剤は、必要に応じて、各種の増感剤と併用してもよい。 In addition, as such a liquid crystal material, when the liquid crystal material is immobilized by cationic polymerization (for example, as described above, when using (containing) a liquid crystalline compound having a cationic polymerizable group as the liquid crystalline compound) ), From the viewpoint of allowing cation polymerization to proceed more easily and quickly, in the liquid crystal material, a photo cation generator and / or a thermal cation generator (in some cases, generating cations by external stimulation such as light and heat) These are generally referred to as “cation generators”). The cation generator may be used in combination with various sensitizers as necessary.
　このような光カチオン発生剤としては、特に制限されず、適当な波長の光を照射することによりカチオンを発生できる化合物を適宜利用することができ、例えば、有機スルフォニウム塩系、ヨードニウム塩系、フォスフォニウム塩系等の化合物を適宜利用することができる。また、このような光カチオン発生剤に利用される前記化合物の対イオンとしては、アンチモネート、フォスフェート、ボレート等が好ましく用いられる。更に、このような光カチオン発生剤に利用される化合物としては、例えば、式：Ａｒ３Ｓ＋ＳｂＦ６ －、Ａｒ３Ｐ＋ＢＦ４ －、Ａｒ２Ｉ＋ＰＦ６ －（ただし、式中のＡｒはフェニル基又は置換フェニル基を示す。）で表わされる化合物、スルホン酸エステル類、トリアジン類、ジアゾメタン類、β－ケトスルホン、イミノスルホナート、ベンゾインスルホナート等が挙げられる。また、このような光カチオン発生剤としては、より具体的には、トリアリルスルフォニウムヘキサフルオロアンチモネート、トリアリルスルフォニウムヘキサフルオロホスフェート等をあげることができる。また、市販品を利用してもよい。 Such a photo cation generator is not particularly limited, and a compound capable of generating a cation by irradiating with light having an appropriate wavelength can be appropriately used. For example, an organic sulfonium salt type, an iodonium salt type, a phosphor type can be used. A compound such as a phonium salt can be used as appropriate. In addition, antimonate, phosphate, borate and the like are preferably used as the counter ion of the compound used in such a photocation generator. Furthermore, examples of the compound used for such a photocation generator include, for example, the formula: Ar 3 S + SbF 6 − , Ar 3 P + BF 4 − , Ar 2 I + PF 6 − (wherein Ar represents a phenyl group or a substituted phenyl group.), Sulfonate esters, triazines, diazomethanes, β-ketosulfone, iminosulfonate, benzoinsulfonate, and the like. More specific examples of such a photocation generator include triallylsulfonium hexafluoroantimonate and triallylsulfonium hexafluorophosphate. Moreover, you may utilize a commercial item.
　また、前記熱カチオン発生剤としては、特に制限されず、適当な温度に加熱されることによりカチオンを発生できる化合物を適宜利用することができ、例えば、ベンジルスルホニウム塩類、ベンジルアンモニウム塩類、ベンジルピリジニウム塩類、ベンジルホスホニウム塩類、ヒドラジニウム塩類、カルボン酸エステル類、スルホン酸エステル類、アミンイミド類、五塩化アンチモン－塩化アセチル錯体、ジアリールヨードニウム塩－ジベンジルオキシ銅、ハロゲン化ホウ素－三級アミン付加物等を適宜利用することができる。 Further, the thermal cation generator is not particularly limited, and a compound capable of generating a cation when heated to an appropriate temperature can be appropriately used. For example, benzylsulfonium salts, benzylammonium salts, benzylpyridinium salts Benzylphosphonium salts, hydrazinium salts, carboxylic acid esters, sulfonic acid esters, amine imides, antimony pentachloride-acetyl chloride complexes, diaryliodonium salts-dibenzyloxycopper, boron halide-tertiary amine adducts, etc. Can be used.
　このようなカチオン発生剤の液晶材料中への添加量は、液晶材料に含有される液晶性化合物のメソゲン部分やスペーサ部分の構造や、オキセタン基の当量、液晶性化合物の配向条件などにより異なるものであるため一概には言えないが、例えば、前記液晶性化合物として前記側鎖型液晶性ポリマーを用いる場合には、前記側鎖型液晶性ポリマーに対して、１００質量ｐｐｍ～２０質量％とすることが好ましく、１０００質量ｐｐｍ～１０質量％とすることがより好ましく、０．５質量％～８質量％とすることが更に好ましく、１質量％～６質量％とすることが最も好ましい。このようなカチオン発生剤の液晶材料中への含有量が１００質量ｐｐｍよりも少ない場合には、発生するカチオンの量が十分なものとならず、重合を効率よく進行させることが困難となる傾向にあり、他方、２０質量％を超えると、液晶層の形成後に液晶層中のカチオン発生剤の分解残存物等の濃度が高くなり、硬化度や耐光性等が低下してしまう傾向にある。 The amount of such a cation generator added to the liquid crystal material varies depending on the structure of the mesogen portion and spacer portion of the liquid crystal compound contained in the liquid crystal material, the equivalent of the oxetane group, the alignment condition of the liquid crystal compound, and the like. Therefore, for example, when the side-chain liquid crystalline polymer is used as the liquid crystalline compound, the content is set to 100 mass ppm to 20 mass% with respect to the side-chain liquid crystalline polymer. It is preferably 1000 mass ppm to 10 mass%, more preferably 0.5 mass% to 8 mass%, and most preferably 1 mass% to 6 mass%. When the content of such a cation generator in the liquid crystal material is less than 100 ppm by mass, the amount of the generated cation is not sufficient, and it tends to be difficult to proceed the polymerization efficiently. On the other hand, if it exceeds 20% by mass, the concentration of the decomposition residue of the cation generator in the liquid crystal layer increases after the liquid crystal layer is formed, and the degree of curing and light resistance tend to decrease.
　また、前記液晶材料としては、液晶層の形成時の塗工性等の観点から、溶媒を含有していてもよい。このような溶媒としては特に制限されず、液晶材料に使用される各種化合物を溶解でき、固定化の際に適当な条件で留去でき、かつ、基材への影響が少ない溶媒であればよく、基材の種類等に応じて種々の溶媒を適宜利用することができる。このような溶媒としては、例えば、アセトン、メチルエチルケトン、イソホロン、シクロヘキサノンなどのケトン類、ブトキシエチルアルコール、ヘキシルオキシエチルアルコール、メトキシ－２－プロパノール、ベンジルオキシエチルアルコールなどのエーテルアルコール類、エチレングリコールジメチルエーテル、ジエチレングリコールジメチルエーテルなどのグリコールエーテル類、酢酸エチル、乳酸エチル、γ－ブチロラクトンなどのエステル類、フェノール、クロロフェノールなどのフェノール類、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアミド、Ｎ－メチルピロリドンなどのアミド類、クロロホルム、テトラクロロエタン、ジクロロベンゼンなどのハロゲン系などやこれらの混合系が好ましく用いられる。 Further, the liquid crystal material may contain a solvent from the viewpoint of coating properties at the time of forming the liquid crystal layer. Such a solvent is not particularly limited as long as it can dissolve various compounds used in the liquid crystal material, can be distilled off under suitable conditions at the time of immobilization, and has little influence on the substrate. Depending on the type of substrate, various solvents can be used as appropriate. Examples of such solvents include ketones such as acetone, methyl ethyl ketone, isophorone, and cyclohexanone, ether alcohols such as butoxyethyl alcohol, hexyloxyethyl alcohol, methoxy-2-propanol, and benzyloxyethyl alcohol, ethylene glycol dimethyl ether, Glycol ethers such as diethylene glycol dimethyl ether, esters such as ethyl acetate, ethyl lactate and γ-butyrolactone, phenols such as phenol and chlorophenol, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. Of these, halogenated compounds such as chloroform, tetrachloroethane, dichlorobenzene, and the like, and mixed systems thereof are preferably used.
　このような溶媒は１種類を単独で使用してもよく或いは二種類以上を併用してもよい。また、このような溶媒は、用いる液晶性化合物の種類、他の成分の種類、それらの含有量等に応じて、その種類や含有量等を適宜設定すればよく、特に制限されるものではないが、前記溶媒の含有量は７０～９９質量％であることが好ましく、７５～９５質量％であることがより好ましい。このような溶媒の含有量が前記下限未満では塗工性が低下する傾向にあり、他方、前記上限を超えると粘度低下による塗工ムラが発生しやすい傾向にある。 Such solvents may be used alone or in combination of two or more. In addition, such a solvent is not particularly limited, and may be appropriately set in accordance with the type of liquid crystal compound used, the type of other components, the content thereof, and the like. However, the content of the solvent is preferably 70 to 99% by mass, and more preferably 75 to 95% by mass. If the content of such a solvent is less than the lower limit, the coating property tends to be reduced, and if it exceeds the upper limit, coating unevenness due to a decrease in viscosity tends to occur.
　また、前記液晶材料には、液晶性を損なわない範囲で、前記液晶性化合物と混和し得る種々の化合物を含有することができる。このような液晶性化合物と混和し得る化合物としては、ビニル基、（メタ）アクリル基等のラジカル重合性基やオキセタン基（前記のオキセタン基を有する化合物を除く）、オキシラニル基、ビニルオキシ基等のカチオン重合性基を有する各種の重合性化合物、カルボキシル基、アミノ基、イソシアナート基などの反応性基を有する化合物、フィルム形成能を有する各種の高分子化合物等を配合することもできる。なお、このような反応性基を有する化合物を含有させることにより、液晶材料に配向処理を施した後、かかる反応性の官能基を利用して反応を進行させることで（官能基の種類に応じて、反応させるに適した条件を適宜採用できる。）、架橋や分子量増大等を達成させることも可能となり、これにより目的とする最終製品の機械強度等の向上に寄与させることもできる。また、本発明の目的を逸脱しない範囲内で、液晶材料中に含有されている化合物の有する反応性の官能基等に応じて、反応開始剤や活性化剤、増感剤、界面活性剤、消泡剤、レベリング剤等を液晶材料中に適宜添加してもよい。 Further, the liquid crystal material can contain various compounds that can be mixed with the liquid crystal compound as long as the liquid crystal properties are not impaired. Examples of compounds miscible with such liquid crystal compounds include radically polymerizable groups such as vinyl groups and (meth) acrylic groups, oxetane groups (excluding compounds having the above oxetane group), oxiranyl groups, vinyloxy groups, and the like. Various polymerizable compounds having a cationic polymerizable group, compounds having a reactive group such as a carboxyl group, an amino group and an isocyanate group, various polymer compounds having a film forming ability, and the like can also be blended. By adding a compound having such a reactive group, the liquid crystal material is subjected to an alignment treatment, and then the reaction is allowed to proceed using the reactive functional group (depending on the type of the functional group). Thus, conditions suitable for the reaction can be appropriately adopted.) Crosslinking, molecular weight increase and the like can also be achieved, and this can contribute to improvement of the mechanical strength and the like of the intended final product. Further, within the range not departing from the object of the present invention, depending on the reactive functional group etc. of the compound contained in the liquid crystal material, a reaction initiator, activator, sensitizer, surfactant, You may add an antifoamer, a leveling agent, etc. in a liquid-crystal material suitably.
　また、前記液晶層は、前記液晶材料をホメオトロピック配向の状態で固定化した層であればよく、特に制限されないが、前記液晶材料を前記基材上に塗布した後に、ホメオトロピック配向となるように配向処理し、その液晶状態を固定化することによって得られる液晶層（前記液晶材料をホメオトロピック配向の状態で固定化した液晶層）であることが好ましい。ここで、前記液晶層における「液晶材料をホメオトロピック配向の状態で固定化した」という状態は、前記液晶材料を固定化（例えば、液晶材料中に架橋基を有する化合物を導入して重合を行ってガラス状態に硬化することで固定化する等）した後に得られる液晶層においてホメオトロピック配向（いわゆる垂直配向：液晶の長軸分子方向が基板に対して実質的に垂直方向に整列している配向）が確認される状態であればよく、前記液晶材料中に含有される化合物等に由来する成分（好ましくは液晶性化合物に由来する成分（液晶性化合物自体、液晶性化合物が分解されて形成された構成物や液晶性化合物の重合物等を含む。））のうちのいずれかが、ホメオトロピック配向の状態で固定化されていればよい。なお、このような配向の状態は偏光顕微鏡を使用して、クロスニコル下での観察を行うことにより確認することができる。また、前記液晶材料の配向処理の方法や固定化（硬化）の方法等に好適な方法については後述の本発明の光学フィルムの製造方法において説明する。 The liquid crystal layer may be a layer in which the liquid crystal material is fixed in a homeotropic alignment state, and is not particularly limited. However, after the liquid crystal material is applied on the base material, the liquid crystal layer becomes homeotropic alignment. It is preferably a liquid crystal layer (liquid crystal layer in which the liquid crystal material is fixed in a homeotropic alignment state) obtained by performing an alignment treatment on the liquid crystal and fixing the liquid crystal state. Here, the state that “the liquid crystal material is fixed in a homeotropic alignment state” in the liquid crystal layer means that the liquid crystal material is fixed (for example, a compound having a crosslinking group is introduced into the liquid crystal material for polymerization). Homeotropic alignment (so-called vertical alignment: alignment in which the long-axis molecular direction of the liquid crystal is aligned substantially perpendicular to the substrate) in the liquid crystal layer obtained after being fixed in a glass state) ) Is confirmed, and the component derived from the compound or the like contained in the liquid crystal material (preferably the component derived from the liquid crystal compound (the liquid crystal compound itself, the liquid crystal compound is decomposed and formed) Or a polymer of a liquid crystal compound, etc.))) may be fixed in a homeotropic alignment state. Such an orientation state can be confirmed by performing observation under crossed Nicols using a polarizing microscope. In addition, a method suitable for the alignment treatment method, the fixing (curing) method, and the like of the liquid crystal material will be described in the optical film manufacturing method of the present invention described later.
　このような液晶層の厚み（膜厚）としては、用途や求める特性によっても異なるものではあるが、０．１～５０μｍであることが好ましく、０．２～２０μｍであることがより好ましく、０．３～１０μｍであることが更に好ましい。このような膜厚が前記下限未満では所望の位相差を発現できなくなる傾向にあり、他方、前記上限を超えると液晶の配向性が悪化する傾向にある。 The thickness (film thickness) of such a liquid crystal layer varies depending on the application and required characteristics, but is preferably 0.1 to 50 μm, more preferably 0.2 to 20 μm, and 0 More preferably, it is 3 to 10 μm. When such a film thickness is less than the lower limit, a desired retardation cannot be exhibited. On the other hand, when the upper limit is exceeded, the orientation of the liquid crystal tends to deteriorate.
　また、前記液晶層は光学フィルムの用途等によっては、膜厚だけでなく、特定の位相差値を有することが要求され得る。ここで、液晶層面内の最大屈折率方向を示す方向の屈折率をＮｘ、それと直交する方向の屈折率をＮｙ、厚さ方向の屈折率をＮｚ、液晶層の厚さをｄ（ｎｍ）とすると、ホメオトロピック配向液晶層の屈折率の関係は、通常、Ｎｚ＞Ｎｘ≧Ｎｙとなる。このようなホメオトロピック配向液晶層に関して、面内のリターデーション値（Ｒｅ＝（Ｎｘ－Ｎｙ）×ｄ［ｎｍ］）としては、０ｎｍ～５０ｎｍ（より好ましくは０ｎｍ～１０ｎｍ）であることが好ましく、厚さ方向のリターデーション値（Ｒｔｈ＝{（Ｎｘ＋Ｎｙ）／２－Ｎｚ}×ｄ［ｎｍ］）としては、－５００ｎｍ～－１０ｎｍ（より好ましくは－３００ｎｍ～－１０ｎｍ）であることが好ましい。なお、このようなＲｅ及びＲｔｈは波長５５０ｎｍ光に対する値である。 The liquid crystal layer may be required to have a specific retardation value as well as a film thickness depending on the use of the optical film. Here, the refractive index in the direction indicating the maximum refractive index direction in the plane of the liquid crystal layer is Nx, the refractive index in the direction orthogonal thereto is Ny, the refractive index in the thickness direction is Nz, and the thickness of the liquid crystal layer is d (nm). Then, the relationship of the refractive index of the homeotropic alignment liquid crystal layer is usually Nz> Nx ≧ Ny. Regarding such homeotropic alignment liquid crystal layer, the in-plane retardation value (Re = (Nx−Ny) × d [nm]) is preferably 0 nm to 50 nm (more preferably 0 nm to 10 nm), The retardation value in the thickness direction (Rth = {(Nx + Ny) / 2−Nz} × d [nm]) is preferably −500 nm to −10 nm (more preferably −300 nm to −10 nm). Such Re and Rth are values for light having a wavelength of 550 nm.
　〈ハードコート層〉
　本発明においては、前記基材上にハードコート層が積層されている。このようなハードコート層は、ウレタン（メタ）アクリレート系樹脂を含むハードコート材料を硬化してなる層である。 <Hard coat layer>
In the present invention, a hard coat layer is laminated on the substrate. Such a hard coat layer is a layer formed by curing a hard coat material containing a urethane (meth) acrylate resin.
　このように、前記ハードコート層を形成するために用いる前記ハードコート材料がウレタン（メタ）アクリレート系樹脂を含むことにより、得られるハードコート層は前記液晶層に対して高度な密着性を示すものとなる。また、このように、前記ウレタン（メタ）アクリレート系樹脂を用いることにより、形成されるハードコート層の柔軟性も十分なものとなり、カール（反り）も抑制することが可能となる。 Thus, when the hard coat material used for forming the hard coat layer contains a urethane (meth) acrylate resin, the resulting hard coat layer exhibits a high degree of adhesion to the liquid crystal layer. It becomes. Moreover, by using the urethane (meth) acrylate resin as described above, the hard coat layer to be formed has sufficient flexibility and curling (warping) can be suppressed.
　このようなウレタン（メタ）アクリレート系樹脂としては、特に制限されず、公知のウレタン（メタ）アクリレート系樹脂を適宜利用することができ、例えば、アクリル酸、メタクリル酸、アクリル酸エステル及びメタクリル酸エステルのうちの少なくとも１種のモノマー；ポリオール；ジイソシアネートを原料化合物として用いて得られる、ウレタン（メタ）アクリレート系樹脂（ウレタンアクリレート系樹脂及び／又はウレタンメタクリレート系樹脂）を適宜利用することができる。すなわち、このようなウレタン（メタ）アクリレート系樹脂としては、例えば、アクリル酸、メタクリル酸、アクリル酸エステル及びメタクリル酸エステルのうちの少なくとも１種のモノマーと、ポリオールとを用いて、水酸基を１個以上有するヒドロキシアクリレート及び水酸基を１個以上有するヒドロキシメタクリレートのうちの少なくとも１種を調製した後、得られたヒドロキシアクリレート及び／又はヒドロキシメタクリレートに対してジイソシアネートを反応させて得られる、ウレタンアクリレート及びウレタンメタクリレートのうちの少なくとも１種を利用することができる。なお、このようなウレタン（メタ）アクリレート系樹脂としては、１種を単独で使用してもよく或いは２種類以上を混合して利用してもよい。 Such urethane (meth) acrylate-based resin is not particularly limited, and known urethane (meth) acrylate-based resins can be appropriately used. For example, acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester Among them, urethane (meth) acrylate resin (urethane acrylate resin and / or urethane methacrylate resin) obtained by using diisocyanate as a raw material compound can be appropriately used. That is, as such a urethane (meth) acrylate-based resin, for example, at least one monomer out of acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester, and a polyol are used to form one hydroxyl group. Urethane acrylate and urethane methacrylate obtained by preparing at least one of hydroxy acrylate and hydroxy methacrylate having one or more hydroxyl groups and then reacting the resulting hydroxy acrylate and / or hydroxy methacrylate with diisocyanate. At least one of them can be used. In addition, as such a urethane (meth) acrylate-type resin, 1 type may be used independently or 2 or more types may be mixed and utilized.
　また、このようなウレタン（メタ）アクリレート系樹脂の原料化合物に利用することが可能な前記アクリル酸エステルとしては、例えば、メチルアクリレート、エチルアクリレート、イソプロピルアクリレート、ブチルアクリレート等のアルキルアクリレート；シクロヘキシルアクリレート等のシクロアルキルアクリレート等があげられる。 Examples of the acrylic ester that can be used as a raw material compound for such urethane (meth) acrylate resins include alkyl acrylates such as methyl acrylate, ethyl acrylate, isopropyl acrylate, and butyl acrylate; cyclohexyl acrylate and the like And cycloalkyl acrylate.
　また、このようなウレタン（メタ）アクリレート系樹脂の原料化合物に利用することが可能な前記メタクリル酸エステルとしては、例えば、メチルメタクリレート、エチルメタクリレート、イソプロピルメタクリレート、ブチルメタクリレート等のアルキルメタクリレート；シクロヘキシルメタクリレート等のシクロアルキルメタクリレート等が挙げられる。 Examples of the methacrylic acid ester that can be used as a raw material compound of such a urethane (meth) acrylate resin include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, and butyl methacrylate; cyclohexyl methacrylate and the like. And cycloalkyl methacrylate.
　前記ウレタン（メタ）アクリレート系樹脂の原料化合物に利用することが可能な前記ポリオールとしては、水酸基を少なくとも２つ有する化合物であればよく、特に制限されないが、例えば、エチレングリコール、１，３－プロピレングリコール、１，２－プロピレングリコール、ジエチレングリコール、ジプロピレングリコール、ネオペンチルグリコール、１，３－ブタンジオール、１，４－ブタンジオール、１，６－ヘキサンジオール、１，９－ノナンジオール、１，１０－デカンジオール、２，２，４－トリメチル－１，３－ペンタンジオール、３－メチル－１，５－ペンタンジオール、ヒドロキシピバリン酸ネオペンチルグリコールエステル、トリシクロデカンジメチロール、１，４－シクロヘキサンジオール、スピログリコール、トリシクロデカンジメチロール、水添ビスフェノールＡ、エチレンオキサイド付加ビスフェノールＡ、プロピレンオキサイド付加ビスフェノールＡ、トリメチロールエタン、トリメチロールプロパン、グリセリン、３－メチルペンタン－１，３，５－トリオール、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、グルコース類等が挙げられる。 The polyol that can be used as a raw material compound of the urethane (meth) acrylate resin is not particularly limited as long as it is a compound having at least two hydroxyl groups, and examples thereof include ethylene glycol and 1,3-propylene. Glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10 -Decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, hydroxypivalic acid neopentyl glycol ester, tricyclodecane dimethylol, 1,4-cyclohexanediol , Spiroglycol Tricyclodecane dimethylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene oxide-added bisphenol A, trimethylolethane, trimethylolpropane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythritol, di Examples include pentaerythritol, tripentaerythritol, and glucoses.
　前記ウレタン（メタ）アクリレート系樹脂の原料化合物に利用することが可能な前記ジイソシアネートとしては、例えば、芳香族、脂肪族又は脂環族の各種のジイソシアネート類を使用することができる。このようなジイソシアネートとしては、例えば、テトラメチレンジイソシアネート、ヘキサメチレンジイソシアネート、イソホロンジイソシアネート、２，４－トリレンジイソシアネート、４，４－ジフェニルジイソシアネート、１，５－ナフタレンジイソシアネート、３，３－ジメチル－４，４－ジフェニルジイソシアネート、キシレンジイソシアネート、トリメチルヘキサメチレンジイソシアネート、４，４－ジフェニルメタンジイソシアネート等、さらにはこれらの水添物等が挙げられる。なお、このようなウレタン（メタ）アクリレート系樹脂の調製の際、各成分の含有比や反応の条件等は特に制限されず、公知の条件等を適宜採用することができ、目的物に応じてその設定を適宜変更することができる。 As the diisocyanate that can be used as a raw material compound of the urethane (meth) acrylate resin, for example, various aromatic, aliphatic, or alicyclic diisocyanates can be used. Examples of such diisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4, Examples thereof include 4-diphenyl diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, and hydrogenated products thereof. In preparing such a urethane (meth) acrylate resin, the content ratio of each component, reaction conditions, etc. are not particularly limited, and known conditions can be adopted as appropriate, depending on the target product. The setting can be changed as appropriate.
　また、このようなウレタン（メタ）アクリレート系樹脂としては、重量平均分子量が５００～２５０００であるものが好ましく、５００～１００００のものが特に好ましい。このような重量平均分子量が前記範囲外の値となる場合には、液晶層の強度が不足したり、配向性が低下する傾向にある。このような重量平均分子量は、テトラヒドロフランを分離液として使用する条件を採用したＧＰＣ測定したデータに基いて、ポリスチレン換算の重量平均分子量として求められる値を採用する。なお、このようなウレタン（メタ）アクリレート系樹脂としては１種を単独で用いてもよく、あるいは、２種以上を混合して利用してもよい。また、このようなウレタン（メタ）アクリレート系樹脂としては、市販のウレタン（メタ）アクリレート系樹脂を適宜利用することができる。 Further, as such a urethane (meth) acrylate resin, those having a weight average molecular weight of 500 to 25000 are preferred, and those having a weight average molecular weight of 500 to 10,000 are particularly preferred. When such a weight average molecular weight becomes a value outside the above range, the strength of the liquid crystal layer tends to be insufficient or the orientation tends to decrease. Such a weight average molecular weight employs a value determined as a polystyrene-reduced weight average molecular weight based on data obtained by GPC measurement under the condition of using tetrahydrofuran as a separation liquid. In addition, as such urethane (meth) acrylate type resin, 1 type may be used independently, or 2 or more types may be mixed and utilized. Moreover, as such a urethane (meth) acrylate resin, a commercially available urethane (meth) acrylate resin can be used as appropriate.
　また、前記ハードコート材料においては、前記ウレタン（メタ）アクリレート系樹脂以外にも他の樹脂成分を含有してもよい。このような他の樹脂成分としては、特に制限されず、アルキル（メタ）アクリレートのポリマー（コポリマーを含む。）、ポリオール（メタ）アクリレート、置換基を有するアルキル基を含有するアルキル（メタ）アクリレートのポリマー（コポリマーを含む。）等を適宜利用することができる。また、このような他の樹脂成分としては、水酸基及びアクリロイル基のうちの少なくとも１種の置換基を有するアルキル基を含有するアルキル（メタ）アクリレートのうちの少なくとも１種のポリマー、コポリマー又はこれらの混合物からなる樹脂成分（Ａ）と；ポリオール（メタ）アクリレートと；を組み合わせて含有することが好ましい。 The hard coat material may contain other resin components in addition to the urethane (meth) acrylate resin. Such other resin components are not particularly limited, and are alkyl (meth) acrylate polymers (including copolymers), polyol (meth) acrylates, alkyl (meth) acrylates containing an alkyl group having a substituent. Polymers (including copolymers) and the like can be used as appropriate. Further, as such other resin component, at least one polymer, copolymer, or these of alkyl (meth) acrylate containing an alkyl group having at least one substituent of hydroxyl group and acryloyl group It is preferable to contain a combination of the resin component (A) made of a mixture; and polyol (meth) acrylate.
　このような他の樹脂成分として好適に用いられる樹脂成分（Ａ）としては、水酸基及びアクリロイル基のうちの少なくとも１種の置換基を有するアルキル基を含有するアルキル（メタ）アクリレートのうちの少なくとも１種のポリマー、コポリマー又はこれらの混合物であればよく、特に制限されるものではないが、例えば、２，３－ジヒドロキシプロピルアクリレート、２，３－ジアクリロイルオキシプロピルアクリレート、２－ヒドロキシ－３－アクリロイルオキシプロピルアクリレート、２－アクリロイルオキシ－３－ヒドロキシプロピルアクリレート、２，３－ジヒドロキシプロピルメタクリレート、２，３－ジアクリロイルオキシプロピルメタクリレート、２－ヒドロキシ－３－アクリロイルオキシプロピルメタクリレート、２－アクリロイルオキシ－３－ヒドロキシプロピルメタクリレート、２－ヒドロキシエチルアクリレート、２－アクリロイルオキシエチルアクリレート、２－ヒドロキシエチルメタクリレートおよび２－アクリロイルオキシメタクリレートからなる群から選択される少なくとも１種のモノマーから形成されたポリマー、コポリマー又はこれらの混合物が挙げられる。 As the resin component (A) suitably used as such other resin component, at least one of alkyl (meth) acrylates containing an alkyl group having at least one substituent of a hydroxyl group and an acryloyl group is used. It may be any kind of polymer, copolymer or mixture thereof, and is not particularly limited. For example, 2,3-dihydroxypropyl acrylate, 2,3-diacryloyloxypropyl acrylate, 2-hydroxy-3-acryloyl Oxypropyl acrylate, 2-acryloyloxy-3-hydroxypropyl acrylate, 2,3-dihydroxypropyl methacrylate, 2,3-diacryloyloxypropyl methacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, 2 Polymer formed from at least one monomer selected from the group consisting of acryloyloxy-3-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-acryloyloxyethyl acrylate, 2-hydroxyethyl methacrylate and 2-acryloyloxy methacrylate , Copolymers or mixtures thereof.
　また、前記他の樹脂成分として好適なポリオール（メタ）アクリレートとしては、特に制限されないが、例えば、ペンタエリスリトールジアクリレート、ペンタエリスリトールトリアクリレート、ペンタエリスリトールテトラアクリレート、ジペンタエリスリトールヘキサアクリレート、１，６－ヘキサンジオールアクリレート、ペンタエリスリトールジメタクリレート、ペンタエリスリトールトリメタクリレート、ペンタエリスリトールテトラメタクリレート、ジペンタエリスリトールヘキサメタクリレート、１，６－ヘキサンジオールメタクリレート等が挙げられる。また、このようなポリオール（メタ）アクリレートとしては、ペンタエリスリトールトリアクリレートとペンタエリスリトールテトラアクリレートとの重合物からなる成分；ペンタエリスリトールトリアクリレートとペンタエリスリトールテトラアクリレートとを含む混合成分；が好ましい。このようなポリオール（メタ）アクリレートは単独で用いてもよく或いは二種類以上を混合して利用してもよい。 The polyol (meth) acrylate suitable as the other resin component is not particularly limited. For example, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 1,6- Examples include hexanediol acrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, and 1,6-hexanediol methacrylate. In addition, as such a polyol (meth) acrylate, a component composed of a polymer of pentaerythritol triacrylate and pentaerythritol tetraacrylate; a mixed component containing pentaerythritol triacrylate and pentaerythritol tetraacrylate is preferable. Such polyol (meth) acrylates may be used alone or in admixture of two or more.
　また、前記ハードコート材料としては、ハードコート層の形成時の塗工性等の観点から、溶媒を含有していてもよい。このような溶媒としては特に制限されず、種々の溶媒を適宜利用することができる。このような溶媒としては、例えば、ジブチルエーテル、ジメトキシメタン、ジメトキシエタン、ジエトキシエタン、プロピレンオキシド、１，４－ジオキサン、１，３－ジオキソラン、１，３，５－トリオキサン、テトラヒドロフラン、アセトン、メチルエチルケトン（ＭＥＫ）、ジエチルケトン、ジプロピルケトン、ジイソブチルケトン、シクロペンタノン、シクロヘキサノン、メチルシクロヘキサノン、蟻酸エチル、蟻酸プロピル、蟻酸ｎ－ペンチル、酢酸メチル、酢酸エチル、プロピオン酸メチル、プロピオン酸エチル、酢酸ｎ－ペンチル、アセチルアセトン、ジアセトンアルコール、アセト酢酸メチル、アセト酢酸エチル、メタノール、エタノール、１－プロパノール、２－プロパノール、１－ブタノール、２－ブタノール、１－ペンタノール、２－メチル－２－ブタノール、シクロヘキサノール、酢酸イソブチル、メチルイソブチルケトン（ＭＩＢＫ）、２－オクタノン、２－ペンタノン、２－ヘキサノン、２－ヘプタノン、３－ヘプタノン、エチレングリコールモノエチルエーテルアセテート、エチレングリコールモノエチルエーテル、エチレングリコールモノブチルエーテル、エチレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノメチルエーテル等が挙げられる。このような溶媒は１種類を単独で使用してもよく或いは二種類以上を併用してもよい。また、このような溶媒は、用いる樹脂成分の組成や含有量等に応じて、その種類や含有比率を適宜設定すればよい。 In addition, the hard coat material may contain a solvent from the viewpoint of coating properties at the time of forming the hard coat layer. Such a solvent is not particularly limited, and various solvents can be appropriately used. Examples of such solvents include dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, acetone, and methyl ethyl ketone. (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, n acetate -Pentyl, acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pe Tanol, 2-methyl-2-butanol, cyclohexanol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, 2-heptanone, 3-heptanone, ethylene glycol monoethyl ether acetate, Examples include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether. Such a solvent may be used individually by 1 type, or may use 2 or more types together. Moreover, what is necessary is just to set the kind and content ratio of such a solvent suitably according to a composition, content, etc. of the resin component to be used.
　また、前記ハードコート材料には、本発明の効果を損なわない範囲において、レベリング剤を添加してもよい。このようなレベリング剤としては、例えば、フッ素系またはシリコーン系のレベリング剤があげられる。また、このようなレベリング剤としては、シリコーン系レベリング剤が好ましい。更に、このようなシリコーン系レベリング剤としては、特に制限されないが、例えば、反応性シリコーン、ポリジメチルシロキサン、ポリエーテル変性ポリジメチルシロキサン、ポリメチルアルキルシロキサン等が挙げられる。このようなシリコーン系レベリング剤の中でも、前記反応性シリコーンが特に好ましい。このようにしてレベリング剤として応性シリコーンを用いることにより、得られるハードコート層の表面に滑り性を付与することが可能となり、耐擦傷性が長期間にわたり持続する傾向にある。 Further, a leveling agent may be added to the hard coat material as long as the effects of the present invention are not impaired. Examples of such a leveling agent include a fluorine-based or silicone-based leveling agent. Moreover, as such a leveling agent, a silicone type leveling agent is preferable. Furthermore, the silicone leveling agent is not particularly limited, and examples thereof include reactive silicone, polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane. Among such silicone leveling agents, the reactive silicone is particularly preferable. Thus, by using a responsive silicone as a leveling agent, it becomes possible to impart slipperiness to the surface of the resulting hard coat layer, and the scratch resistance tends to persist for a long period of time.
　前記ハードコート材料には、本発明の効果を損なわない範囲において、必要に応じ、顔料、充填剤、分散剤、可塑剤、紫外線吸収剤、界面活性剤、防汚剤、酸化防止剤、チクソトロピー化剤等の添加剤を適宜利用してもよい。このような添加剤は一種類を単独で使用してもよく、また二種類以上併用してもよい。 In the hard coat material, as long as the effects of the present invention are not impaired, a pigment, a filler, a dispersant, a plasticizer, an ultraviolet absorber, a surfactant, an antifouling agent, an antioxidant, a thixotropic agent, if necessary. You may utilize suitably additives, such as an agent. Such additives may be used alone or in combination of two or more.
　また、前記ハードコート材料には、用いる樹脂成分の種類等に応じて、公知の光重合開始剤を用いることができる。このような光重合開始剤としては、例えば、１－ヒドロキシシクロヘキシルフェニルケトン（ＩＲＧ－１８４）、２，２－ジメトキシ－２－フェニルアセトフェノン、アセトフェノン、ベンゾフェノン、キサントン、３－メチルアセトフェノン、４－クロロベンゾフェノン、４，４’－ジメトキシベンゾフェノン、ベンゾインプロピルエーテル、ベンジルジメチルケタール、Ｎ，Ｎ，Ｎ’，Ｎ’－テトラメチル－４，４’－ジアミノベンゾフェノン、１－（４－イソプロピルフェニル）－２－ヒドロキシ－２－メチルプロパン－１－オン、チオキサントン系化合物等を利用することができる。 Also, a known photopolymerization initiator can be used for the hard coat material according to the type of resin component used. Examples of such a photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (IRG-184), 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, 3-methylacetophenone, 4-chlorobenzophenone. 4,4′-dimethoxybenzophenone, benzoinpropyl ether, benzyldimethyl ketal, N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone, 1- (4-isopropylphenyl) -2-hydroxy -2-Methylpropan-1-one, thioxanthone compounds, and the like can be used.
　前記ハードコート材料中のウレタン（メタ）アクリレート系樹脂の含有量としては、特に制限されるものではないが、得られるハードコート層の硬度の観点等からは、前記ハードコート材料中の樹脂成分の総量に対して、１５～５５質量％であることが好ましく、２５～４５質量％であることがより好ましい。なお、ここにいう樹脂成分の総量とは、ハードコート材料中に含まれている樹脂成分の合計量をいい、例えば、ウレタン（メタ）アクリレート系樹脂とともに上述の樹脂成分（Ａ）やポリオール（メタ）アクリレートを更に含有する場合には、ウレタン（メタ）アクリレート系樹脂と樹脂成分（Ａ）とポリオール（メタ）アクリレートとの合計量（総量）をいい、更に他の樹脂成分を含有する場合には、前記合計量に更に他の樹脂成分の量を合計して得られる量（総量）をいう。また、このようなウレタン（メタ）アクリレート系樹脂の含有量が前記下限未満では硬度等の硬化物物性が低下する傾向にあり、他方、前記上限を超えるとフィルムのカールの発生を十分に防止することが困難となる傾向にある。 The content of the urethane (meth) acrylate resin in the hard coat material is not particularly limited, but from the viewpoint of the hardness of the obtained hard coat layer, the resin component in the hard coat material The total amount is preferably 15 to 55% by mass, more preferably 25 to 45% by mass. The total amount of the resin component referred to here means the total amount of the resin component contained in the hard coat material. For example, the resin component (A) or polyol (meta) together with the urethane (meth) acrylate resin. ) When further containing acrylate, it refers to the total amount (total amount) of urethane (meth) acrylate resin, resin component (A) and polyol (meth) acrylate, and when further containing other resin components The amount (total amount) obtained by further adding the amount of other resin components to the total amount. Further, when the content of such urethane (meth) acrylate resin is less than the lower limit, the cured product physical properties such as hardness tend to be lowered. On the other hand, when the upper limit is exceeded, the curling of the film is sufficiently prevented. Tend to be difficult.
　また、このような樹脂成分の総量は、前記ハードコート材料中、９０～９９．９質量％であることが好ましく、９５～９９．５質量％であることがより好ましい。このような樹脂成分の総量が前記下限未満では、ハードコート層を効率よく形成することが困難となる傾向にあり、他方、前記上限を超えるとハードコート層の膜厚制御が困難となる傾向にある。 Further, the total amount of such resin components is preferably 90 to 99.9% by mass, and more preferably 95 to 99.5% by mass in the hard coat material. If the total amount of such resin components is less than the lower limit, it tends to be difficult to efficiently form a hard coat layer, whereas if it exceeds the upper limit, it tends to be difficult to control the thickness of the hard coat layer. is there.
　また、前記ハードコート材料中に前記樹脂成分（Ａ）を含有させる場合においては、樹脂成分（Ａ）の含有量は、特に制限されるものではないが、前記ウレタン（メタ）アクリレート系樹脂１００質量部に対して２５～１１０質量部であることが好ましく、４５～８５質量部であることがより好ましい。このような樹脂成分（Ａ）の含有量が前記上限を超えると、ハードコート材料の塗工性が低下する傾向にあり、他方、樹脂成分（Ａ）の配合割合が前記下限未満の場合には、ハードコート材料を硬化する際に硬化収縮を防止することが困難となり、カールの発生を十分に防止することが困難となる傾向にある。 In addition, when the resin component (A) is contained in the hard coat material, the content of the resin component (A) is not particularly limited, but the urethane (meth) acrylate resin 100 mass. The amount is preferably 25 to 110 parts by mass, more preferably 45 to 85 parts by mass with respect to parts. When the content of the resin component (A) exceeds the upper limit, the coatability of the hard coat material tends to be reduced, and on the other hand, when the blending ratio of the resin component (A) is less than the lower limit. When the hard coat material is cured, it becomes difficult to prevent curing shrinkage, and it tends to be difficult to sufficiently prevent the occurrence of curling.
　さらに、前記ハードコート材料中にポリオール（メタ）アクリレートを含有させる場合においては、ポリオール（メタ）アクリレートの含有量は、特に制限されるものではないが、前記ウレタン（メタ）アクリレート系樹脂１００質量部に対して７０～１８０質量部であることが好ましく、１００～１５０質量部であることがより好ましい。前記ポリオール（メタ）アクリレートの含有量が前記上限を超えると、ハードコート層の形成時に硬化収縮を効率よく防止することが困難となり、ハードコート層のカールを十分に防止することができなくなり、屈曲性の低下を十分に防止することが困難となる。また、前記ポリオール（メタ）アクリレートの含有量が前記下限未満では、ハードコート層の硬度を十分なものとすることが困難となり、耐擦傷性が低下する傾向にある。 Furthermore, when the polyol (meth) acrylate is contained in the hard coat material, the content of the polyol (meth) acrylate is not particularly limited, but 100 parts by mass of the urethane (meth) acrylate resin The amount is preferably 70 to 180 parts by mass, and more preferably 100 to 150 parts by mass. If the content of the polyol (meth) acrylate exceeds the upper limit, it becomes difficult to efficiently prevent curing shrinkage during the formation of the hard coat layer, and curling of the hard coat layer cannot be sufficiently prevented. It is difficult to sufficiently prevent the deterioration of the property. Moreover, if content of the said polyol (meth) acrylate is less than the said minimum, it will become difficult to make hardness of a hard-coat layer sufficient, and it exists in the tendency for abrasion resistance to fall.
　また、前記ハードコート材料中に溶媒を含有させる場合においては、前記溶媒の含有量は９５質量％以下であることが好ましく、９０質量％以下であることがより好ましい。このような溶媒の含有量が前記上限を超えるとレベリング性が低下し、塗工ムラを生じやすくなる傾向にある。 In addition, when the hard coat material contains a solvent, the content of the solvent is preferably 95% by mass or less, and more preferably 90% by mass or less. When the content of such a solvent exceeds the above upper limit, the leveling property tends to be lowered and coating unevenness tends to occur.
　前記レベリング剤の含有量としては、特に制限されるものではないが、前記樹脂成分の総量１００質量部に対して、５質量部以下であることが好ましく、０．０１～５質量部であることがより好ましい。なお、このようなハードコート材料としては、各成分の調製方法やその混合方法等も特に制限されず、公知の方法で適宜製造したものを利用することができる。また、このようなハードコート材料としては、前記ウレタン（メタ）アクリレート系樹脂を含有しているものであればよく、市販品を適宜利用してもよく、例えば、大成ファインケミカル株式会社製の商品名「８ＵＸ－０１５Ａ」、東亞合成株式会社製の商品名「アロニックス　Ｍ－１１００」等を使用することができる。 The content of the leveling agent is not particularly limited, but is preferably 5 parts by mass or less, and 0.01 to 5 parts by mass with respect to 100 parts by mass of the total resin component. Is more preferable. In addition, as such a hard-coat material, the preparation method of each component, its mixing method, etc. are not restrict | limited in particular, What was suitably manufactured by the well-known method can be utilized. Moreover, as such a hard-coat material, what is necessary is just to contain the said urethane (meth) acrylate type-resin, and you may utilize a commercial item suitably, for example, the brand name by Taisei Fine Chemical Co., Ltd. “8UX-015A”, trade name “Aronix M-1100” manufactured by Toagosei Co., Ltd., etc. can be used.
　また、前記ハードコート層は、前記ハードコート材料を硬化してなる層であるが、このような硬化の好適な条件等については、後述の本発明の光学フィルムの製造方法において説明する。また、このようなハードコート材料を硬化して得られる、ハードコート層においては、そのハードコート層（樹脂層）中における前記ウレタン（メタ）アクリレート系樹脂に由来する成分の含有量は１５～５５質量％であることが好ましく、２５～４５質量％であることがより好ましい。このような含有量が前記下限未満では硬度等の硬化物物性が低下する傾向にあり、他方、前記上限を超えるとフィルムのカールの発生を十分に防止するのが困難となる傾向にある。 Further, the hard coat layer is a layer formed by curing the hard coat material, and suitable conditions for such curing will be described in the optical film production method of the present invention described later. Further, in the hard coat layer obtained by curing such a hard coat material, the content of the component derived from the urethane (meth) acrylate resin in the hard coat layer (resin layer) is 15 to 55. The content is preferably mass%, more preferably 25 to 45 mass%. If such a content is less than the lower limit, the cured product physical properties such as hardness tend to be lowered. On the other hand, if it exceeds the upper limit, it tends to be difficult to sufficiently prevent the curling of the film.
　さらに、このようなハードコート層の厚み（膜厚）としては、１５μｍ以下であることが好ましく、０．１～５μｍであることがより好ましく、０．１～３μｍであることが更に好ましい。このような厚みが前記下限未満ではハードコート層に十分な硬度を付与することが困難となり、耐傷性が低下する傾向にあり、他方、前記上限を超えると、硬化時にカールが大きくなるため、例えば、フィルムを形成する際、ハードコート材料の塗工時にライン走行性が低下する傾向にある。 Furthermore, the thickness (film thickness) of such a hard coat layer is preferably 15 μm or less, more preferably 0.1 to 5 μm, and further preferably 0.1 to 3 μm. If such a thickness is less than the lower limit, it becomes difficult to impart sufficient hardness to the hard coat layer, and the scratch resistance tends to decrease.On the other hand, if the upper limit is exceeded, curling increases at the time of curing. When the film is formed, the line running property tends to be lowered when the hard coat material is applied.
　また、このようなハードコート層としては、その硬度は層の厚みにも影響されるものであり、特に制限されるものではないが、鉛筆硬度において、６Ｂ～４Ｈの硬度を有することが好ましく、５Ｂ～２Ｈの硬度を有することがより好ましい。このような硬度が前記下限未満では耐キズ性能が低下する傾向にあり、他方、前記上限を超えるとクラック耐性が低下する傾向にある。なお、このような鉛筆硬度の値は、１９９９年発行のＪＩＳ　Ｋ５６００－５－４に規定されている方法に準拠して測定することにより求めることができる。 In addition, the hardness of such a hard coat layer is also affected by the thickness of the layer, and is not particularly limited. However, the pencil hardness preferably has a hardness of 6B to 4H. More preferably, it has a hardness of 5B to 2H. When such hardness is less than the lower limit, scratch resistance tends to be reduced, and when it exceeds the upper limit, crack resistance tends to be reduced. Such a pencil hardness value can be obtained by measuring in accordance with a method defined in JIS K5600-5-4 issued in 1999.
　なお、このようなハードコート層を前記液晶層と組み合わせて用いることにより、前記液晶層の耐傷性を向上させることが可能となるばかりか、前記液晶層との間の十分な密着性を得ることが可能となる。そして、このようなハードコート層を前記液晶層と組み合わせて用いることにより、前記液晶層中の液晶の配向状態が熱により変化することを十分に抑制することが可能な、優れた耐熱性を光学フィルムに付与することも可能となる。 By using such a hard coat layer in combination with the liquid crystal layer, not only can the scratch resistance of the liquid crystal layer be improved, but also sufficient adhesion between the liquid crystal layer can be obtained. Is possible. Further, by using such a hard coat layer in combination with the liquid crystal layer, it is possible to sufficiently suppress the change in the alignment state of the liquid crystal in the liquid crystal layer due to heat, and to have excellent heat resistance. It can also be applied to the film.
　また、このような本発明の光学フィルムは、前記基材、前記液晶層及び前記ハードコート層を備えるものであればよく、その製造方法としては、後述の本発明の光学フィルムの製造方法を好適に採用することができる。 Moreover, such an optical film of the present invention only needs to include the base material, the liquid crystal layer, and the hard coat layer, and the production method of the optical film of the present invention described later is suitable as the production method. Can be adopted.
　［光学フィルムの製造方法］
　本発明の光学フィルムの製造方法は、基材上に液晶材料をホメオトロピック配向の状態で固定化した液晶層を積層した後、前記液晶層上にウレタン（メタ）アクリレート系樹脂を含むハードコート材料を塗布し、硬化することによりハードコート層を積層し、
　前記基材と、前記基材上に積層された前記液晶層と、前記液晶層上に積層された前記ハードコート材料を硬化してなる前記ハードコート層とを備える光学フィルムを得る、方法である。 [Method for producing optical film]
In the method for producing an optical film of the present invention, a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state is laminated on a base material, and then a hard coat material containing a urethane (meth) acrylate resin on the liquid crystal layer Apply and cure to laminate a hard coat layer,
It is a method of obtaining an optical film provided with the substrate, the liquid crystal layer laminated on the substrate, and the hard coat layer formed by curing the hard coat material laminated on the liquid crystal layer. .
　このような光学フィルムの製造方法に記載されている「基材」、「液晶層」、「ハードコート層」、「液晶材料」、「ハードコート材料」等はいずれも、上述の本発明の光学フィルムにおいて説明したものと同様のものである。 Any of the “substrate”, “liquid crystal layer”, “hard coat layer”, “liquid crystal material”, “hard coat material” and the like described in the method for producing such an optical film is the optical material of the present invention described above. This is the same as described in the film.
　ここで、先ず、前記基材上に液晶材料をホメオトロピック配向の状態で固定化した液晶層を積層する方法について説明する。このような液晶層を積層する方法としては、基材上に液晶材料をホメオトロピック配向の状態で固定化した液晶層を、前記基材上に積層することが可能な方法であればよく、特に制限されるものではないが、前記基材上に前記液晶材料を塗布した後に、ホメオトロピック配向となるように配向処理し、その液晶状態を固定化することによって、前記基材上に前記液晶材料をホメオトロピック配向の状態で固定化した液晶層を積層する方法を採用することが好ましい。 Here, first, a method of laminating a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state on the substrate will be described. As a method for laminating such a liquid crystal layer, any method can be used as long as a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state on a substrate can be laminated on the substrate. Although not limited, after applying the liquid crystal material on the base material, the liquid crystal material is applied onto the base material by performing an alignment treatment so as to be homeotropic alignment and fixing the liquid crystal state. It is preferable to employ a method of laminating a liquid crystal layer in which is fixed in a homeotropic alignment state.
　前記基材上に前記液晶材料を塗布する方法としては、特に制限されず、前記液晶材料の種類に応じて、塗膜の均一性を確保できるような方法であればよく、溶媒を含有しない液晶材料を直接塗布する方法であっても、溶媒を含有する液晶材料（液晶材料の溶液）を塗布する方法であってもよい。このような液晶材料を塗布する方法としては、特に限定されず、公知の方法を適宜採用することができ、例えば、フレキソ印刷方式、オフセット印刷方式、ディスペンサー方式、グラビアコート方式、マイクログラビア方式、バーコート方式、スクリーン印刷方式、リップコート方式、ダイコート方式等の塗工方法を適宜採用することができる。このような塗布方法の中でも、グラビアコート方式、キスコート方式やリップコート方式とダイコート方式を採用することが好ましい。なお、前記基材上に均一な塗膜を形成するために、塗布する前に表面改質処理としてコロナ処理やプラズマ処理を行ってもよい。 The method for applying the liquid crystal material on the substrate is not particularly limited, and may be any method that can ensure the uniformity of the coating film according to the type of the liquid crystal material, and does not contain a solvent. Even if it is the method of apply | coating material directly, the method of apply | coating the liquid crystal material (solution of liquid crystal material) containing a solvent may be sufficient. A method for applying such a liquid crystal material is not particularly limited, and a known method can be appropriately employed. For example, a flexographic printing method, an offset printing method, a dispenser method, a gravure coating method, a micro gravure method, a bar Coating methods such as a coating method, a screen printing method, a lip coating method, and a die coating method can be appropriately employed. Among such coating methods, it is preferable to employ a gravure coating method, a kiss coating method, a lip coating method, and a die coating method. In addition, in order to form a uniform coating film on the base material, corona treatment or plasma treatment may be performed as surface modification treatment before coating.
　また、前記液晶材料の溶液を塗布する場合には、塗布後に塗膜から溶媒を除去（留去）するための乾燥工程を施すことが好ましい。このような乾燥工程は、塗膜の均一性が維持される方法であればよく、特に限定されず、公知の方法を採用することができ、例えば、ヒーター（炉）、温風吹きつけ等の方法を採用してもよい。また、このような塗布工程より得られる塗膜の膜厚は、用いる液晶材料の種類や得られる液晶層の用途等により適宜調整されるものであるため、一概には決められないが、乾燥後の膜厚が０．１～５０μｍ（より好ましくは０．２～２０μｍ、更に好ましくは０．３～１０μｍ）となるようにすることが好ましい。このような乾燥後の膜厚が前記範囲外となるような場合には、配向が不十分になる傾向にある。また、このような乾燥後の膜厚が、前記下限未満では所望の位相差を発現できなくなる傾向にあり、他方、前記上限を超えると液晶の配向性が低下する傾向にある。 In addition, when applying the liquid crystal material solution, it is preferable to perform a drying step for removing (evaporating) the solvent from the coating film after the application. Such a drying step is not particularly limited as long as the uniformity of the coating film is maintained, and a known method can be employed, for example, a method such as a heater (furnace), hot air blowing, etc. May be adopted. In addition, since the film thickness of the coating film obtained from such a coating process is appropriately adjusted depending on the type of liquid crystal material to be used and the use of the obtained liquid crystal layer, etc., it cannot be generally determined, but after drying The film thickness is preferably 0.1 to 50 μm (more preferably 0.2 to 20 μm, still more preferably 0.3 to 10 μm). When the film thickness after such drying is out of the above range, the orientation tends to be insufficient. Further, when the film thickness after drying is less than the lower limit, a desired phase difference tends not to be expressed. On the other hand, when the film thickness exceeds the upper limit, the orientation of the liquid crystal tends to be lowered.
　また、前記基材上に前記液晶材料を塗布した後に、前記液晶材料をホメオトロピック配向となるように配向処理する方法（配向処理の方法）としては、特に制限されず、前記液晶材料中の前記液晶化合物の種類に応じてホメオトロピック配向を形成することが可能な公知の方法と適宜採用することができ、例えば、前記液晶材料の塗膜を熱処理する方法を採用してもよい。 In addition, the method of aligning the liquid crystal material so as to be homeotropic alignment after applying the liquid crystal material on the substrate (method of alignment treatment) is not particularly limited, and the liquid crystal material in the liquid crystal material is not limited. Depending on the type of the liquid crystal compound, a known method capable of forming homeotropic alignment can be employed as appropriate. For example, a method of heat-treating the coating film of the liquid crystal material may be employed.
　このように配向処理の方法に熱処理する方法を採用する場合、かかる熱処理としては、使用した液晶材料に応じて、その液晶材料中の前記液晶性化合物の液晶相発現温度範囲内において加熱する方法を挙げることができ、その条件は公知の条件の中で適宜設定することができる。このような熱処理を施す配向処理の方法によって、前記液晶材料中の前記液晶性化合物が本来有する自己配向能を利用して、液晶をホメオトロピック配向させることが可能となる。また、このような熱処理の条件としては、用いる液晶性化合物等の種類によって液晶相挙動温度（転移温度）の最適条件や限界値が異なるものであるため、一概には言えないが、その温度条件が、１０～２００℃（より好ましくは３０～１５０℃）の温度範囲内の温度であって、且つ、前記液晶材料中の前記液晶性化合物のガラス転移点（Ｔｇ）以上の温度（更に好ましくはＴｇより１０℃以上高い温度）であるという条件を満たすことがより好ましい。このような熱処理温度が前記下限未満では、液晶配向が十分に進行しない傾向にあり、他方、前記上限を超えると、基材が劣化する等、基材の強度等に問題が生じる傾向にある。また、このような熱処理の時間についても、液晶をホメオトロピック配向させることが可能な範囲であればよく、特に制限されないが、３秒～３０分であることが好ましく、１０秒～１０分であることがより好ましい。このような熱処理の時間が３秒より短い場合には、液晶配向（ホメオトロピック配向）を十分に完成させることが困難となる傾向にあり、他方、３０分を超えると、液晶層の生産性が低下する傾向にある。 Thus, when adopting a method of heat treatment as the alignment treatment method, the heat treatment is a method of heating within the liquid crystal phase expression temperature range of the liquid crystalline compound in the liquid crystal material, depending on the liquid crystal material used. The conditions can be appropriately set among known conditions. By the alignment treatment method in which such heat treatment is performed, the liquid crystal can be homeotropically aligned by utilizing the self-alignment ability inherent in the liquid crystal compound in the liquid crystal material. In addition, as the conditions for such heat treatment, the optimum conditions and limit values of the liquid crystal phase behavior temperature (transition temperature) vary depending on the type of liquid crystal compound used, etc. Is a temperature within a temperature range of 10 to 200 ° C. (more preferably 30 to 150 ° C.), and a temperature not lower than the glass transition point (Tg) of the liquid crystalline compound in the liquid crystal material (more preferably It is more preferable to satisfy the condition that the temperature is 10 ° C. or more higher than Tg. If the heat treatment temperature is less than the lower limit, the liquid crystal alignment tends not to proceed sufficiently. On the other hand, if the heat treatment temperature exceeds the upper limit, the base material tends to deteriorate, and the strength of the base material tends to be problematic. Further, the time for such heat treatment is not particularly limited as long as the liquid crystal can be homeotropically aligned, but it is preferably 3 seconds to 30 minutes, and preferably 10 seconds to 10 minutes. It is more preferable. When the time for such heat treatment is shorter than 3 seconds, it tends to be difficult to sufficiently complete liquid crystal alignment (homeotropic alignment). On the other hand, when it exceeds 30 minutes, the productivity of the liquid crystal layer is low. It tends to decrease.
　また、前記配向処理後において、形成された液晶状態（ホメオトロピック配向の配向状態）を固定化する方法としては、用いる液晶材料の種類に応じて公知の方法を適宜採用することができる。このような固定化の方法としては、例えば、反応性官能基を含有する液晶性化合物を含有する液晶材料を用いた場合には、光照射及び／又は加熱処理により前記反応性官能基を反応させて、ホメオトロピック配向の配向状態で配向を固定化する方法を採用してもよい。このように、反応性官能基を含有する液晶性化合物を用いた場合に、光照射及び／又は加熱処理により前記反応性官能基を反応させて、ホメオトロピック配向の配向状態で配向を固定化することで、配向を形成した後に、その液晶の配向状態を十分に保ったまま液晶を固定化することが可能である。また、このように反応性官能基を反応させるために、液晶材料に反応開始剤（例えば前述のカチオン発生剤等）を含有せしめて、その反応開始剤の機能を発現させて前記反応を進行させることが好ましい。 In addition, as a method for fixing the formed liquid crystal state (homeotropic alignment state) after the alignment treatment, a known method can be appropriately employed depending on the type of liquid crystal material to be used. As such a fixing method, for example, when a liquid crystal material containing a liquid crystal compound containing a reactive functional group is used, the reactive functional group is reacted by light irradiation and / or heat treatment. Thus, a method of fixing the alignment in the homeotropic alignment state may be employed. Thus, when a liquid crystalline compound containing a reactive functional group is used, the reactive functional group is reacted by light irradiation and / or heat treatment to fix the alignment in the homeotropic alignment state. Thus, after the alignment is formed, it is possible to fix the liquid crystal while maintaining the alignment state of the liquid crystal sufficiently. Further, in order to react the reactive functional group in this way, a reaction initiator (for example, the above-mentioned cation generator) is contained in the liquid crystal material, and the function of the reaction initiator is expressed to advance the reaction. It is preferable.
　このように、前記液晶材料に前記反応開始剤を含有させる場合であって、かかる反応開始剤が光の照射により開始剤の機能を発現するようなものである場合（例えば、光カチオン発生剤の場合）には、光照射によりホメオトロピック配向の配向状態で配向を固定化することが好ましい。このような光照射の方法としては特に制限されず、例えば、用いる反応開始剤の吸収波長領域にスペクトルを有する光源（例えばメタルハライドランプ、高圧水銀灯、超高圧水銀灯、低圧水銀灯、キセノンランプ、アークランプ、レーザーなど）を用いて、その光源からの光を照射する方法が挙げられる。なお、このような光の照射により反応開始剤を活性化させることが可能となり、効率よく反応性官能基を反応させることが可能となる。 As described above, when the reaction initiator is contained in the liquid crystal material and the reaction initiator expresses the function of the initiator by irradiation with light (for example, a photocation generator) In the case), the orientation is preferably fixed in the homeotropic orientation state by light irradiation. The light irradiation method is not particularly limited. For example, a light source having a spectrum in the absorption wavelength region of the reaction initiator to be used (for example, a metal halide lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, And a method of irradiating light from the light source using a laser or the like. In addition, it becomes possible to activate a reaction initiator by such light irradiation, and it becomes possible to react a reactive functional group efficiently.
　また、このような光照射の方法において光の積算照射量としては、波長３６５ｎｍでの積算露光量として、１０～２０００ｍＪ／ｃｍ２であることが好ましく、５０～１０００ｍＪ／ｃｍ２であることがより好ましい。ただし、前記反応開始剤の吸収領域と、光源のスペクトルが著しく異なる場合や、液晶性化合物自身に光源波長光の吸収能がある場合等は、この限りではない。これらの場合には、より効率よく配向状態を維持したまま、塗膜を固定化（硬化）させるという観点から、適当な光増感剤や、吸収波長の異なる２種以上の反応開始剤を混合して用いる等の方法を採用してもよい。また、このような光照射時の温度条件は、該液晶材料が液晶配向をとる温度範囲とるすことが好ましく、反応の効果を十分に上げるためには、前記液晶性化合物のＴｇ以上の液晶相温度で光照射を行うのが好ましい。 Further, in such a light irradiation method, the integrated dose of light is preferably 10 to 2000 mJ / cm 2 and more preferably 50 to 1000 mJ / cm 2 as the integrated exposure at a wavelength of 365 nm. preferable. However, this is not the case when the absorption region of the reaction initiator and the spectrum of the light source are significantly different, or when the liquid crystalline compound itself has the ability to absorb light of the light source wavelength. In these cases, an appropriate photosensitizer and two or more reaction initiators having different absorption wavelengths are mixed from the viewpoint of fixing (curing) the coating film while maintaining the orientation state more efficiently. For example, a method such as use may be employed. In addition, the temperature condition at the time of such light irradiation is preferably a temperature range in which the liquid crystal material takes a liquid crystal alignment, and in order to sufficiently enhance the reaction effect, a liquid crystal phase of Tg or more of the liquid crystalline compound is used. It is preferable to perform light irradiation at a temperature.
　また、前記液晶材料に前記反応開始剤を含有させる場合であって、かかる反応開始剤が熱により開始剤の機能を発現するようなものである場合（例えば、熱カチオン発生剤の場合）には、加熱処理によりホメオトロピック配向の配向状態で配向を固定化することが好ましい。このような加熱処理の条件としては、特に制限されず、反応開始剤の種類に応じて、配向状態が十分に維持されるように温度条件を選択すればよく、公知の条件を適宜採用することができる。 In the case where the reaction initiator is contained in the liquid crystal material and the reaction initiator expresses the function of the initiator by heat (for example, in the case of a thermal cation generator). The orientation is preferably fixed in a homeotropic orientation state by heat treatment. The conditions for such heat treatment are not particularly limited, and the temperature conditions may be selected according to the type of the reaction initiator so that the orientation state is sufficiently maintained, and known conditions are appropriately employed. Can do.
　このようにして、前記基材上に前記液晶材料を塗布した後に、ホメオトロピック配向となるように配向処理し、その液晶状態を固定化することによって、前記基材上に前記液晶材料をホメオトロピック配向の状態で固定化した液晶層を積層することが可能となる。 In this way, after applying the liquid crystal material on the substrate, the liquid crystal material is homeotropically aligned by fixing the liquid crystal state by performing an alignment treatment so as to be homeotropic alignment. A liquid crystal layer fixed in an aligned state can be stacked.
　次に、前記液晶層上にウレタン（メタ）アクリレート系樹脂を含むハードコート材料を塗布し、硬化することによりハードコート層を積層する工程について説明する。 Next, a process of laminating a hard coat layer by applying a hard coat material containing a urethane (meth) acrylate resin on the liquid crystal layer and curing it will be described.
　このようなハードコート材料を塗布する方法としては、特に制限されず、公知の方法を適宜採用することができ、例えば、例えば、ファンテンコート方式、ダイコート方式、スピンコート方式、スプレーコート方式、グラビアコート方式、ロールコート方式、バーコート方式等の塗工方法を用いることができる。 A method for applying such a hard coat material is not particularly limited, and a known method can be appropriately employed. For example, a fountain coat method, a die coat method, a spin coat method, a spray coat method, a gravure, etc. Coating methods such as a coating method, a roll coating method, and a bar coating method can be used.
　このようにして前記ハードコート材料を塗布して前記液晶層上に塗膜を形成した後に、前記塗膜を硬化させる場合、その硬化工程に先立ち、前記塗膜を乾燥させる工程を施すことが好ましい。このような乾燥工程において採用する乾燥の方法は特に制限されず、公知の方法を適宜採用でき、例えば、自然乾燥でもよいし、風を吹きつけての風乾であってもよいし、加熱乾燥であってもよいし、これらを組み合わせた方法であってもよい。 In this way, after the hard coat material is applied and a coating film is formed on the liquid crystal layer, when the coating film is cured, a step of drying the coating film is preferably performed prior to the curing step. . The drying method employed in such a drying step is not particularly limited, and a known method can be employed as appropriate. For example, natural drying, air drying by blowing air, or heat drying can be used. There may be a method that combines these methods.
　また、このようなハードコート材料を塗布する際の膜厚としては、用いるハードコート材料の種類等により適宜調整されるものであるため、一概には決められないが、乾燥後の膜厚が０．１～１５μｍ（より好ましくは０．１～１０μｍ、更に好ましくは０．１～５μｍ）となるようにすることが好ましい。このような乾燥後の膜厚が、前記下限未満では乾燥ムラが多発する傾向にあり、他方、前記上限を超えると硬化後のカールの発生を十分に防止するのが困難となる傾向にある。 Further, the film thickness at the time of applying such a hard coat material is appropriately determined depending on the type of the hard coat material to be used and the like, and thus cannot be generally determined, but the film thickness after drying is 0. It is preferable that the thickness is 1 to 15 μm (more preferably 0.1 to 10 μm, still more preferably 0.1 to 5 μm). If the film thickness after drying is less than the lower limit, uneven drying tends to occur frequently. On the other hand, if the film thickness exceeds the upper limit, it tends to be difficult to sufficiently prevent curling after curing.
　また、このようにして前記ハードコート材料を塗布して前記液晶層上に塗膜を形成した後、硬化前に、酸素による硬化反応阻害を防止する観点から、前記塗膜の表面上に高分子フィルム（例えば、ポリエチレンテレフタレート（ＰＥＴ）フィルム、トリアセチルセルロース（ＴＡＣ）フィルム、ポリカーボネートフィルム、ポリエチレンナフタレート（ＰＥＮ）、ポリフェニレンサルファイド（ＰＰＳ）等）を積層してもよい。なお、このような高分子フィルムは、前記ハードコート材料の塗膜の硬化後に剥離することで、基板フィルム上にハードコート薄膜を形成することが可能となる。 In addition, after coating the hard coat material in this way to form a coating film on the liquid crystal layer, before curing, a polymer is formed on the surface of the coating film from the viewpoint of preventing curing reaction inhibition by oxygen. A film (for example, polyethylene terephthalate (PET) film, triacetyl cellulose (TAC) film, polycarbonate film, polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), etc.) may be laminated. In addition, it becomes possible to form a hard coat thin film on a board | substrate film by peeling such a polymer film after hardening of the coating film of the said hard-coat material.
　また、前記ハードコート材料の塗膜の硬化方法は、特に制限されないが、熱により硬化する方法又はハードコート材料に対して電離放射線を照射することにより硬化する方法を採用することが好ましく、ハードコート材料に対して電離放射線を照射することにより硬化する方法を採用することがより好ましい。 Further, the method for curing the coating film of the hard coat material is not particularly limited, but it is preferable to employ a method of curing by heat or a method of curing by irradiating the hard coat material with ionizing radiation. It is more preferable to employ a method of curing by irradiating the material with ionizing radiation.
　さらに、このようなハードコート材料に対して電離放射線を照射することにより硬化する方法を採用する場合には、前記電離放射線としては各種活性エネルギー線を用いることができ、特に制限されないが、紫外線（ＵＶ）を用いることが好ましい。また、このような活性エネルギー線の線源としては、公知の線源を適宜利用することができ、特に制限されないが、高圧水銀ランプ、ハロゲンランプ、キセノンランプ、メタルハライドランプ、窒素レーザー、電子線加速装置、放射性元素等の線源を好適に利用することができる。さらに、前記電離放射線の照射量は特に制限されず、ハードコート材料を硬化させることが可能な条件であればよい。このような電離放射線の照射量としては、紫外線波長３６５ｎｍでの積算露光量として、５０～５０００ｍＪ／ｃｍ２であることが好ましい。このような電離放射線の照射量が、５０ｍＪ／ｃｍ２未満であれば、硬化を十分に行うことが困難となり、得られるハードコート層の硬度が低下する傾向にあり、他方、５０００ｍＪ／ｃｍ２を超えると、形成されるハードコート層が着色し易くなり、光学フィルムの性能が低下する傾向にある。 Furthermore, when adopting a method of curing by irradiating such hard coat material with ionizing radiation, various active energy rays can be used as the ionizing radiation, and although not particularly limited, UV) is preferably used. In addition, as a source of such active energy rays, a known radiation source can be used as appropriate, and is not particularly limited, but is not limited to a high pressure mercury lamp, halogen lamp, xenon lamp, metal halide lamp, nitrogen laser, electron beam acceleration. A radiation source such as an apparatus or a radioactive element can be preferably used. Furthermore, the irradiation amount of the ionizing radiation is not particularly limited as long as the hard coat material can be cured. The irradiation dose of such ionizing radiation is preferably 50 to 5000 mJ / cm 2 as an integrated exposure dose at an ultraviolet wavelength of 365 nm. The dose of such ionizing radiation, is less than 50 mJ / cm 2, it is difficult to sufficiently perform the curing, tend to hardness of the hard coat layer obtained is decreased, while the 5000 mJ / cm 2 If it exceeds, the formed hard coat layer tends to be colored, and the performance of the optical film tends to be lowered.
　このように、基材上に液晶材料をホメオトロピック配向の状態で固定化した液晶層を積層した後、前記液晶層上にウレタン（メタ）アクリレート系樹脂を含むハードコート材料を塗布し、硬化することによりハードコート層を積層することで、前記基材と、前記基材上に積層された前記液晶層と、前記液晶層上に積層された前記ハードコート材料を硬化してなる前記ハードコート層とを備える光学フィルムを得ることが可能となる。そして、このようにして光学フィルムを製造することで、上記本発明の光学フィルムを得ることができる。 Thus, after laminating a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state on a base material, a hard coat material containing a urethane (meth) acrylate resin is applied on the liquid crystal layer and cured. By laminating a hard coat layer, the hard coat layer is obtained by curing the base material, the liquid crystal layer laminated on the base material, and the hard coat material laminated on the liquid crystal layer. It becomes possible to obtain an optical film provided with. And the optical film of the said this invention can be obtained by manufacturing an optical film in this way.
　このような光学フィルムの製造方法により得られる上記本発明の光学フィルムにおいては、前記ホメオトロピック配向液晶層と前記特定のハードコート層とを組み合わせて利用しているため、前記液晶層と前記ハードコート層との間の密着性を十分に高度なものとすることができ、外力による剥がれなどが十分に抑制される。更に、このようにして得られる光学フィルムにおいては、前記ハードコート層によって前記液晶層に対して十分に優れた耐熱性を付与できるため、熱により液晶層の配向状態が変化することを十分に抑制することが可能であり、熱による劣化が十分に抑制される。また、このような光学フィルムは、前記液晶層上に前記ハードコート層を備えるものとなるため、耐傷性が十分に高度なものとなっており、例えば、他の材料（例えば直線偏光板）等との積層体を形成する場合において、その積層体の製造過程におけるフィルムの搬送時に、搬送ロールとの接触により液晶層に傷が入ることや、光学フィルムと偏光板とを一体加工する際に、その貼合工程で液晶層表面へのロールの接触等により液晶層に傷が入ること等が、前記ハードコート層により十分に抑制され、傷による品質の低下も十分に抑制することができる。そのため、このような光学フィルムにおいては、液晶層の特性を十分に維持し、発揮させることが可能であり、使用時や偏光板等への応用時に品質が低下することを十分に抑制できる。 In the optical film of the present invention obtained by such a method for producing an optical film, the liquid crystal layer and the hard coat are used because the homeotropic alignment liquid crystal layer and the specific hard coat layer are used in combination. Adhesion between the layers can be made sufficiently high, and peeling due to external force can be sufficiently suppressed. Furthermore, in the optical film obtained in this way, the hard coat layer can give sufficiently excellent heat resistance to the liquid crystal layer, so that the orientation state of the liquid crystal layer is sufficiently suppressed from being changed by heat. And deterioration due to heat is sufficiently suppressed. In addition, since such an optical film is provided with the hard coat layer on the liquid crystal layer, the scratch resistance is sufficiently high. For example, other materials (for example, linear polarizing plates), etc. When the film is transported in the manufacturing process of the laminate, the liquid crystal layer is damaged by contact with the transport roll, or when the optical film and the polarizing plate are integrally processed, In the bonding step, scratches on the liquid crystal layer due to contact of the roll with the surface of the liquid crystal layer and the like are sufficiently suppressed by the hard coat layer, and deterioration in quality due to scratches can be sufficiently suppressed. Therefore, in such an optical film, the characteristics of the liquid crystal layer can be sufficiently maintained and exhibited, and deterioration in quality during use or application to a polarizing plate or the like can be sufficiently suppressed.
　また、このような光学フィルムとしては、その用途は特に制限されず、例えば、前記ホメオトロピック配向液晶層の特性を利用することが可能な用途に適宜利用できる。このようなホメオトロピック配向液晶層の特性を利用することが可能な光学フィルムの用途としては、例えば、前記ホメオトロピック配向液晶層が所定の位相差を示すので、それ自体を位相差フィルム等として利用することや、偏光板や位相差板等の光学部材（素子）の材料として利用すること等が挙げられる。例えば、このような光学フィルムは、公知の各種偏光板（例えば偏光素子単体や偏光素子の両側または片側に透光性保護フィルムを有するもの等）や公知の各種位相差フィルム（例えばポリマーフィルムや液晶性の化合物や組成物から形成されるもの等）と組み合わせて積層体とし、楕円偏光板、位相差板、色補償板、視野角改良板等の光学素子として用いてもよい。また、前記光学フィルムは、複数の位相差フィルムと積層して用いてもよい。このような積層体は通常、偏光板や位相差フィルムにズレや歪み等が発生しないように接着剤や粘着剤を用いて形成できる。更に、このような光学フィルムとしては、その構成中に膜厚方向に、より大きな屈折率を有するホメオトロピック配向（垂直配向）の液晶層を有しているため、例えば、各種画像表示装置の視野角改善のための光学素子（偏光板や位相差フィルム等）等の材料に好適に利用できる。 Further, the use of such an optical film is not particularly limited, and can be appropriately used for, for example, a use capable of utilizing the characteristics of the homeotropic alignment liquid crystal layer. As an application of the optical film capable of utilizing the characteristics of the homeotropic alignment liquid crystal layer, for example, the homeotropic alignment liquid crystal layer exhibits a predetermined retardation, so that itself is used as a retardation film or the like. And use as a material for an optical member (element) such as a polarizing plate or a retardation plate. For example, such an optical film includes various known polarizing plates (for example, a polarizing element alone or a film having a light-transmitting protective film on both sides or one side of the polarizing element) and various known retardation films (for example, polymer films and liquid crystals). Or a compound formed of a functional compound or a composition) to form a laminate, and may be used as an optical element such as an elliptically polarizing plate, a retardation plate, a color compensation plate, and a viewing angle improving plate. The optical film may be laminated with a plurality of retardation films. Such a laminate can usually be formed using an adhesive or a pressure-sensitive adhesive so as not to cause displacement or distortion in the polarizing plate or the retardation film. Furthermore, since such an optical film has a liquid crystal layer of homeotropic alignment (vertical alignment) having a larger refractive index in the film thickness direction in its configuration, for example, the field of view of various image display devices. It can be suitably used for materials such as an optical element (polarizing plate, retardation film, etc.) for improving the angle.
　［偏光板、画像表示装置］
　本発明の偏光板は、上記本発明の光学フィルムを備えるものである。このような偏光板としては、特に制限されないが、上記本発明の光学フィルム中の前記ホメオトロピック配向液晶層の特性を利用することが可能となるように、上記本発明の光学フィルムを公知の光学部材と適宜組み合わせる等して偏光板として利用すればよく、例えば、上記本発明の光学フィルムと直線偏光板とを組み合わせて楕円偏光板としてもよく、上記本発明の光学フィルムと輝度上昇フィルムとを組み合わせてＬＣＤバックライト側用偏光板としてもよい。このように、前記偏光板の構成は特に制限されず、上記本発明の光学フィルム中の前記ホメオトロピック配向液晶層の特性や、その使用目的等に応じて、他の光学部材との組み合わせ等を適宜考慮して、その設計を適宜変更することができ、これにより各種偏光板として利用すればよい。なお、本発明においては、上記本発明の光学フィルムが前記ハードコート層を備えるため、他の光学部材（例えば前述の直線偏光板）等と積層体を形成して、これを偏光板として利用する場合等において、その積層体の製造過程におけるフィルムの搬送時に搬送ロールとの接触によりフィルム中の液晶層に傷が入ることや、光学フィルムと偏光板とを一体加工する際に、その貼合工程で液晶層表面へのロールの接触等による液晶層に傷が入ること等が十分に抑制され、傷による品質の低下を十分に抑制することができる。このように、上記本発明の光学フィルムがハードコート層により十分な耐傷性を有するため、本発明の偏光板は、品質の低下を十分に抑制しながら効率よく製造することが可能である。 [Polarizing plate, image display device]
The polarizing plate of the present invention comprises the optical film of the present invention. Such a polarizing plate is not particularly limited, but the optical film of the present invention is known optically so that the characteristics of the homeotropic alignment liquid crystal layer in the optical film of the present invention can be utilized. What is necessary is just to use it as a polarizing plate combining suitably with a member etc., for example, it is good also as an elliptically polarizing plate combining the optical film of the above-mentioned present invention, and a linear polarizing plate. It is good also as a polarizing plate for LCD backlight sides combining. As described above, the configuration of the polarizing plate is not particularly limited. Depending on the characteristics of the homeotropic alignment liquid crystal layer in the optical film of the present invention, the purpose of use, and the like, combinations with other optical members, etc. With appropriate consideration, the design can be changed as appropriate, so that it can be used as various polarizing plates. In the present invention, since the optical film of the present invention includes the hard coat layer, a laminate is formed with another optical member (for example, the above-mentioned linear polarizing plate) and the like, and this is used as a polarizing plate. In some cases, when the film is transported in the production process of the laminate, the liquid crystal layer in the film is damaged by contact with the transport roll, or when the optical film and the polarizing plate are integrally processed, the bonding step Thus, it is possible to sufficiently prevent the liquid crystal layer from being damaged due to the contact of the roll with the surface of the liquid crystal layer, and to sufficiently suppress the deterioration of quality due to the scratch. Thus, since the optical film of the present invention has sufficient scratch resistance due to the hard coat layer, the polarizing plate of the present invention can be efficiently produced while sufficiently suppressing deterioration in quality.
　ここで、このような本発明の偏光板について、その好適な一実施形態として、上記本発明の光学フィルムに直線偏光板を積層して得ることが可能な楕円偏光板を例に挙げて説明する。このような楕円偏光板は、上記本発明の光学フィルムと前記直線偏光板とを積層一体化したものである。このような直線偏光板としては特に制限されず、公知の直線偏光板を適宜利用することができ、例えば、偏光子の片側または両側に保護フィルムを有するものを使用できる。このような偏光子は特に制限されず、各種のものを適宜使用でき、例えば、ポリビニルアルコール系フィルム、部分ホルマール化ポリビニルアルコール系フィルム、エチレン・酢酸ビニル共重合体系部分ケン化フィルム等の親水性高分子フィルムに、ヨウ素や二色性染料等の二色性物質を吸着させて一軸延伸したもの、ポリビニルアルコールの脱水処理物やポリ塩化ビニルの脱塩酸処理物等のポリエン系配向フィルム等が挙げられる。これらのなかでもポリビニルアルコール系フィルムを延伸して二色性材料（沃素、染料）を吸着、配向したものが好適に用いられる。また、このような偏光子の厚さも特に制限されないが、５～８０μｍ程度が一般的である。また、前記保護フィルムとしては、特に制限されず、公知の材料からなる保護フィルムを適宜利用することができる。このような保護フィルムとしては、偏光特性や耐久性などの点より、トリアセチルセルロース等のセルロース系ポリマーからなるものが好ましい。また、前記光学フィルムと前記直線偏光板とを積層一体化する方法も特に制限されないが、例えば、前記光学フィルムと前記直線偏光板の互いに積層すべき面の一方または両方に適宜な方法で粘着剤及び／又は接着剤層を形成した後、圧着すればよい。圧着は毎葉形態、長尺形態のいずれでも行うことができ、使用する装置もそれぞれの形態に適した装置を用いればよく、プレス、ラミネーター等を例示できる。また、このような粘着剤層及び／又は接着剤層を形成するための材料も特に制限されず、公知の材料を適宜利用することができる。 Here, such a polarizing plate of the present invention will be described as an example of an elliptically polarizing plate that can be obtained by laminating a linear polarizing plate on the optical film of the present invention. . Such an elliptically polarizing plate is obtained by laminating and integrating the optical film of the present invention and the linearly polarizing plate. Such a linear polarizing plate is not particularly limited, and a known linear polarizing plate can be appropriately used. For example, one having a protective film on one side or both sides of a polarizer can be used. Such a polarizer is not particularly limited, and various types of polarizers can be used as appropriate. For example, a highly hydrophilic film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or an ethylene / vinyl acetate copolymer partially saponified film. Examples include uniaxially stretched films obtained by adsorbing dichroic substances such as iodine and dichroic dyes on molecular films, and polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. . Among these, a film obtained by stretching a polyvinyl alcohol film and adsorbing and orienting a dichroic material (iodine, dye) is preferably used. The thickness of such a polarizer is not particularly limited, but is generally about 5 to 80 μm. Moreover, it does not restrict | limit especially as said protective film, The protective film which consists of a well-known material can be utilized suitably. Such a protective film is preferably made of a cellulose-based polymer such as triacetyl cellulose from the viewpoints of polarization characteristics and durability. In addition, the method of laminating and integrating the optical film and the linear polarizing plate is not particularly limited. For example, the pressure-sensitive adhesive can be appropriately formed on one or both of the surfaces of the optical film and the linear polarizing plate to be laminated with each other. And after forming an adhesive bond layer, it should just carry out pressure bonding. The crimping can be performed either in a leaf-like form or in a long form, and the apparatus to be used may be an apparatus suitable for each form, and examples thereof include a press and a laminator. Moreover, the material for forming such a pressure-sensitive adhesive layer and / or adhesive layer is not particularly limited, and a known material can be appropriately used.
　また、本発明の画像表示装置は、上記本発明の偏光板を備えるものである。このような本発明の画像表示装置としては、上記本発明の偏光板を備えていればよく、画像表示装置の種類は特に制限されず、液晶表示装置や有機ＥＬ表示装置、プラズマディスプレイ等のような公知の画像表示装置を適宜利用することができる。また、上記本発明の偏光板を画像表示装置に配置する方法等も特に制限されず、公知の方法を適宜利用することができる。このように、上記本発明の偏光板を備える本発明の画像表示装置は、膜厚方向に、より大きな屈折率を有するホメオトロピック配向（垂直配向）の液晶層を備える上記本発明の光学フィルムを利用したものとなることから、その特性に応じて、例えば、その画像表示装置の視野角を十分に広げたり、輝度を十分に向上させたりすること等が可能となり、これにより視野角向上や画質向上を十分に図ることができる。 The image display device of the present invention includes the polarizing plate of the present invention. Such an image display device of the present invention only needs to include the polarizing plate of the present invention, and the type of the image display device is not particularly limited, such as a liquid crystal display device, an organic EL display device, and a plasma display. Such known image display devices can be used as appropriate. Further, the method for arranging the polarizing plate of the present invention in an image display device is not particularly limited, and a known method can be appropriately used. As described above, the image display device of the present invention including the polarizing plate of the present invention includes the optical film of the present invention including a homeotropic alignment (vertical alignment) liquid crystal layer having a larger refractive index in the film thickness direction. Depending on the characteristics, for example, the viewing angle of the image display device can be sufficiently widened or the luminance can be sufficiently improved, thereby improving the viewing angle and image quality. Improvement can be sufficiently achieved.
　以下、実施例及び比較例に基づいて本発明をより具体的に説明するが、本発明は以下の実施例に限定されるものではない。 Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.
　（調製例１：液晶フィルム［ホメオトロピック液晶層とＣＯＰフィルムの積層体］の調製）
　先ず、ラジカル重合により合成して一般式（１０）： (Preparation Example 1: Preparation of liquid crystal film [laminate of homeotropic liquid crystal layer and COP film])
First, it is synthesized by radical polymerization and is represented by the general formula (10):
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000008
で表わされる側鎖型液晶性ポリマーを準備した。このようにして得られた側鎖型液晶性ポリマーの分子量をＧＰＣにより測定（測定条件：東ソー製高速ＧＰＣ装置ＥｃｏＳｅｃ　ＨＬＣ－８３２０ＧＰＣを使用。カラムはＴＳＫｇｅｌＳｕｐｅｒＨ４０００、ＴＳＫｇｅｌＳｕｐｅｒＨ１０００、ＴＳＫｇｅｌＳｕｐｅｒＭＰ（ＨＺ）－Ｈ、ＴＳＫｇｅｌＭｕｌｔｉｐｏｒｅＨＺ－Ｈを使用。カラムオーブン温度：４０℃、分離溶媒：テトラヒドロフラン、流速：０．３５ｍｌ／ｍｉｎを採用）したところ、ポリスチレン換算による重量平均分子量は９７００であった。なお、上記一般式（１０）における数値の表記は、各ユニットの構成比を表すものであって、ブロック重合体を意味するものではない。 A side chain type liquid crystalline polymer represented by the formula: The molecular weight of the side chain type liquid crystalline polymer thus obtained was measured by GPC (measurement conditions: using a high-speed GPC device EcoSec HLC-8320GPC manufactured by Tosoh. Columns were TSKgelSuperH4000, TSKgelSuperH1000, TSKgelSuperMP (HZ) -H, TSKgelHultipor H. Column oven temperature: 40 ° C., separation solvent: tetrahydrofuran, flow rate: 0.35 ml / min was adopted), and the weight average molecular weight in terms of polystyrene was 9700. In addition, the description of the numerical value in the said General formula (10) represents the component ratio of each unit, and does not mean a block polymer.
　次いで、上記一般式（１０）で表わされる側鎖型液晶性ポリマー０．７７ｇと、下記一般式（１１）： Next, 0.77 g of the side chain type liquid crystalline polymer represented by the above general formula (10) and the following general formula (11):
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000009
で表されるアクリル化合物０．１５ｇと、下記一般式（１２）： 0.15 g of an acrylic compound represented by the following general formula (12):
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000010
で表されるジオキセタン化合物０．０８ｇとを、９ｍｌのシクロヘキサノン中に添加し、溶解させて溶液を得た後に、暗所にて、前記溶液に対して、トリアリルスルフォニウムヘキサフルオロアンチモネートを５０質量％含有するプロピレンカーボネート溶液（アルドリッチ社製、試薬）を０．１ｇ加え、孔径０．４５μｍのポリテトラフルオロエチレン製のフィルターでろ過することにより溶液状態の液晶材料（溶媒の含有量９０質量％、溶媒：シクロヘキサノン）を調製した。 After adding 0.08 g of the dioxetane compound represented by the following formula in 9 ml of cyclohexanone and dissolving it to obtain a solution, triallylsulfonium hexafluoroantimonate is added to the solution in the dark. 0.1 g of a propylene carbonate solution containing 50% by mass (produced by Aldrich, reagent) is added, and the solution is filtered through a polytetrafluoroethylene filter having a pore size of 0.45 μm to obtain a liquid crystal material in a solution state (solvent content of 90 mass) %, Solvent: cyclohexanone).
　次いで、前記溶液状態の液晶材料を、ＣＯＰフィルム（ＪＳＲ株式会社製の商品名「アートン」、Ｒｅ１＝１００ｎｍ、膜厚２８μｍ）上にスピンコート法で塗布し、得られた塗膜を６０℃のホットプレートで１０分乾燥した後に、前記乾燥後の塗膜とＣＯＰフィルムとの積層物に対して、９０℃のオーブンで２分間熱処理を施し、前記塗膜（液晶層）を形成する液晶材料を配向させて、液晶材料がホメオトロピック配向した塗膜（膜厚１．１μｍ）を備える積層体を得た。次いで、前記液晶材料がホメオトロピック配向した塗膜を備える積層体を、６０℃に加熱したアルミ板上に密着させて置き、その上から、高圧水銀灯ランプにより、６００ｍＪ／ｃｍ２の紫外光（ただし、３６５ｎｍの波長の光を測定した光量）を照射して、前記配向処理後の塗膜（液晶層）を硬化させて、配向状態を固定化し、配向状態が固定化された液晶層（膜厚１．０μｍ）を備える液晶フィルム（液晶層／ＣＯＰフィルム）を得た。 Next, the liquid crystal material in the solution state was applied onto a COP film (trade name “ARTON” manufactured by JSR Corporation, Re1 = 100 nm, film thickness 28 μm) by a spin coating method, and the obtained coating film was applied at 60 ° C. After drying on a hot plate for 10 minutes, the laminate of the dried coating film and COP film is heat-treated in an oven at 90 ° C. for 2 minutes to form a liquid crystal material that forms the coating film (liquid crystal layer). A laminate having a coating film (film thickness: 1.1 μm) in which the liquid crystal material was homeotropically aligned was obtained. Next, a laminate including a coating film in which the liquid crystal material is homeotropically oriented is placed in close contact with an aluminum plate heated to 60 ° C., and from there, a high-pressure mercury lamp lamp is used to radiate 600 mJ / cm 2 ultraviolet light (however, A liquid crystal layer (film thickness) in which the alignment state is fixed and the alignment state is fixed by irradiating a coating film (liquid crystal layer) after the alignment treatment by irradiating a 365 nm wavelength light. A liquid crystal film (liquid crystal layer / COP film) having 1.0 μm) was obtained.
　このようにして得られた液晶フィルムを、クロスニコルさせた偏光顕微鏡下で観察すると、ディスクリネーションがなくモノドメインの均一な配向で、このフィルムを傾けて斜めから光を入射し、同様にクロスニコルで観察したところ、光の透過が観測された。また、得られた液晶フィルムの光学位相差を王子計測機器株式会社製の自動複屈折計（商品名「ＫＯＢＲＡ２１　ＡＤＨ」）を用いて測定した。なお、このような光学位相差の測定に際しては、測定光を液晶フィルムの表面に対して垂直或いは斜めの方向から入射したところ、液晶フィルムの表面に対して垂直方向での位相差（面内位相差）がほぼゼロで、液晶層の遅相軸方向に斜めから位相差を測定したところ、測定光の入射角度の増加に伴い位相差値が増加したことから、液晶層がホメオトロピック配向の状態で固定化されていることが確認された。なお、このような測定により、前記液晶フィルム中の前記液晶層の単独のリターデーション（波長５５０ｎｍ光に対するリターデーション）は、Ｒｅが０ｎｍ、Ｒｔｈが－２３ｎｍと見積もられた。 When the liquid crystal film thus obtained was observed under a polarizing microscope in which crossed Nicols were used, the film was tilted and light was incident obliquely with uniform monodomain orientation without disclination. When observed with Nicol, light transmission was observed. Moreover, the optical phase difference of the obtained liquid crystal film was measured using an automatic birefringence meter (trade name “KOBRA21 ADH”) manufactured by Oji Scientific Instruments. In measuring the optical phase difference, when the measurement light is incident from a direction perpendicular or oblique to the surface of the liquid crystal film, the phase difference (in-plane position) in the direction perpendicular to the surface of the liquid crystal film is measured. The phase difference was almost zero, and when the phase difference was measured obliquely in the slow axis direction of the liquid crystal layer, the phase difference value increased with the increase in the incident angle of the measurement light, so the liquid crystal layer was in a homeotropic alignment state. It was confirmed that it was fixed by. By such measurement, the single retardation of the liquid crystal layer in the liquid crystal film (retardation with respect to light having a wavelength of 550 nm) was estimated to be 0 nm for Re and −23 nm for Rth.
　（実施例１）
　調製例１で得られた液晶フィルム（ホメオトロピック配向の液晶層／ＣＯＰフィルム）の液晶層上に、ウレタンアクリレート系樹脂を含有するハードコート材料（大成ファインケミカル株式会社製の商品名「８ＵＸ－０１５Ａ（ウレタンアクリレート系樹脂の重量平均分子量：１０００、溶媒：無し、不揮発成分の含有量：９９質量％）」と、光重合開始剤（１－ヒドロキシシクロヘキシルフェニルケトン、チバ・ジャパン株式会社製の商品名「ＩＲＧ－１８４」）との混合物（混合物中の光重合開始剤の含有量０．４質量％））を、乾燥硬化後の厚みが１．５μｍとなるようにして塗布した後、得られた塗膜の表面上にポリエチレンテレフタレート（ＰＥＴ）フィルムを積層した。次いで、前記塗膜に対して前記ＰＥＴフィルム側から６００ｍＪ／ｃｍ２の紫外線光（ただし、３６５ｎｍの波長の光を測定した光量）を照射してハードコート材料を硬化させ、ハードコート層を形成し、ＰＥＴフィルム／ハードコート層／ホメオトロピック液晶層／ＣＯＰフィルムの層構成を持つ多層フィルムを得た（ハードコート層の厚みは１．５μｍ）。次いで、得られた多層フィルムから前記ＰＥＴフィルムを剥離して光学フィルム（ＣＯＰフィルム／ホメオトロピック配向液晶層／ハードコート層の層構成）を得た。 (Example 1)
On the liquid crystal layer of the liquid crystal film (homeotropic alignment liquid crystal layer / COP film) obtained in Preparation Example 1, a hard coat material containing a urethane acrylate resin (trade name “8UX-015A manufactured by Taisei Fine Chemical Co., Ltd.”) Urethane acrylate resin weight average molecular weight: 1000, solvent: none, nonvolatile component content: 99% by mass) ”and photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, trade name“ Ciba Japan Co., Ltd. ” IRG-184 ") and a mixture (the content of the photopolymerization initiator in the mixture is 0.4% by mass)) so that the thickness after drying and curing is 1.5 μm, A polyethylene terephthalate (PET) film was laminated on the surface of the membrane. Next, the hard coat material is cured by irradiating the coating film with ultraviolet light of 600 mJ / cm 2 from the PET film side (however, the amount of light measured at a wavelength of 365 nm) to form a hard coat layer. A multilayer film having a layer structure of PET film / hard coat layer / homeotropic liquid crystal layer / COP film was obtained (the thickness of the hard coat layer was 1.5 μm). Subsequently, the PET film was peeled off from the obtained multilayer film to obtain an optical film (layer structure of COP film / homeotropic alignment liquid crystal layer / hard coat layer).
　（比較例１）
　調製例１で得られた液晶フィルムをそのまま比較のための光学フィルムとした。 (Comparative Example 1)
The liquid crystal film obtained in Preparation Example 1 was used as an optical film for comparison.
　（比較例２）
　ウレタンアクリレート系樹脂を含有するハードコート材料の代わりに、ウレタンアクリレート系樹脂以外のアクリレート系樹脂を含有するハードコート材料（大成ファインケミカル株式会社製の商品名「８ＫＸ－０７７（アクリレート系樹脂の重量平均分子量：２１０００、溶媒：酢酸ブチル／ノルマルプロピルアセテート／メチルエチルケトン＝１０／６０／３０混合溶媒、不揮発成分の含有量：４０質量％：なお、ウレタン（メタ）アクリレート系樹脂を含まない材料である。）」と、光重合開始剤（１－ヒドロキシシクロヘキシルフェニルケトン、チバ・ジャパン株式会社製の商品名「ＩＲＧ－１８４」）との混合物（混合物中の光重合開始剤の含有量０．４質量％））を用いた以外は、実施例１と同様にして、比較のための光学フィルム（ＣＯＰフィルム／ホメオトロピック配向液晶層／ハードコート層の層構成）を得た。 (Comparative Example 2)
Hard coat material containing acrylate resin other than urethane acrylate resin instead of hard acrylate resin containing urethane acrylate resin (trade name “8KX-077 made by Taisei Fine Chemical Co., Ltd. (weight average molecular weight of acrylate resin) : 21000, solvent: butyl acetate / normal propyl acetate / methyl ethyl ketone = 10/60/30 mixed solvent, content of nonvolatile components: 40% by mass: Note that this is a material that does not contain urethane (meth) acrylate resin. And a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, trade name “IRG-184” manufactured by Ciba Japan Co., Ltd.) (content of photopolymerization initiator in the mixture is 0.4 mass%)) In the same manner as in Example 1 except that the optical fiber for comparison was used. It was obtained beam (layer configuration of the COP film / homeotropic alignment liquid crystal layer / hard coat layer).
　（比較例３）
　先ず、調製例１で採用した方法と同様の方法を採用して溶液状態の液晶材料（液晶性組成物）を調製した。次に、ラビング処理を行ったポリビニルアルコール／ポリエチレンナフタレート（ＰＶＡ／ＰＥＮ：なお、ＰＶＡは日本酢ビポバール株式会社製の商品名「ＰＸＰ－０５」を使用し、ＰＥＮは帝人株式会社製の商品名「テオネックス　Ｑ５１」を使用）の積層体からなる基板フィルムのＰＶＡ層上に、前記溶液状態の液晶材料を塗工し、得られた塗膜を６０℃のホットプレートで１０分乾燥した後に、前記乾燥後の塗膜と基板フィルム（ＰＶＡ／ＰＥＮフィルム）との積層物に対して、１４５℃のオーブンを用いて１分間の熱処理を施し、一度、オーブンから熱処理後の積層物を取り出して室温（２５℃）まで冷却した後、かかる冷却後の積層物に対して、１４５℃のオーブンを用いて１分３０秒間の熱処理を施すことにより、前記塗膜（液晶層）を形成する液晶材料を配向させて、液晶材料がホモジニアス配向した塗膜（膜厚１．１μｍ）を備える積層体を得た。次いで、前記液晶材料がホモジニアス配向した塗膜を備える積層体を、６０℃に加熱したアルミ板上に密着させて置き、その上から、高圧水銀灯ランプにより、６００ｍＪ／ｃｍ２の紫外光（ただし、３６５ｎｍの波長の光を測定した光量）を照射して、前記配向処理後の塗膜（液晶層）を硬化させて、配向状態を固定化し、配向状態が固定化された液晶層（膜厚１．０μｍ）を備えるフィルム（液晶層／基板フィルム［ＰＶＡ／ＰＥＮ］の層構成）を得た。 (Comparative Example 3)
First, a liquid crystal material (liquid crystal composition) in a solution state was prepared by employing the same method as that employed in Preparation Example 1. Next, rubbing-treated polyvinyl alcohol / polyethylene naphthalate (PVA / PEN: PVA uses the product name “PXP-05” manufactured by Nihon Vinegar Bipoval Co., Ltd., and PEN uses the product name manufactured by Teijin Ltd. After applying the solution-state liquid crystal material on the PVA layer of the substrate film composed of a laminate of “Teonex Q51”) and drying the obtained coating film on a hot plate at 60 ° C. for 10 minutes, The laminate of the dried coating film and the substrate film (PVA / PEN film) is subjected to heat treatment for 1 minute using an oven at 145 ° C., and once the laminate after heat treatment is taken out of the oven at room temperature ( After cooling to 25 ° C.), the coated film (liquid crystal) is subjected to heat treatment for 1 minute 30 seconds using an oven at 145 ° C. with respect to the cooled laminate. The liquid crystal material forming the layer) was aligned to obtain a laminate including a coating film (film thickness 1.1 μm) in which the liquid crystal material was homogeneously aligned. Next, the laminate including the coating film in which the liquid crystal material is homogeneously oriented is placed in close contact with an aluminum plate heated to 60 ° C., and from there, a high-pressure mercury lamp lamp is used to emit 600 mJ / cm 2 ultraviolet light (however, A liquid crystal layer (film thickness 1) in which the alignment state is fixed by irradiating the coating film (liquid crystal layer) after the alignment treatment by irradiating 365 nm wavelength light). .Mu.m) (liquid crystal layer / substrate film [PVA / PEN] layer structure).
　このようにして得られたフィルムの液晶層上にＵＶ硬化型アクリル樹脂（東亞合成製ＵＶ－３４００）を塗布し、塗膜を形成した後、該塗膜の表面上をトリアセチルセルロース
（ＴＡＣ）フィルム（富士フイルム株式会社製の商品名「ＴＤＹ８０」）で覆い、積層体（ＴＡＣ／ＵＶ－３４００／液晶層／ＰＶＡ／ＰＥＮの層構成）を得た。次に、得られた積層体の上から高圧水銀灯ランプにより、６００ｍＪ／ｃｍ２の紫外光（ただし、３６５ｎｍの波長の光を測定した光量）を照射して、前記アクリル樹脂の塗膜を硬化させた後、該積層体から基板フィルム（ＰＶＡ／ＰＥＮフィルム）を剥離することにより、液晶フィルム（ＴＡＣ／ＵＶ－３４００／液晶層の層構成）を得た。 A UV curable acrylic resin (UV-3400 manufactured by Toagosei Co., Ltd.) was applied on the liquid crystal layer of the film thus obtained to form a coating film, and then the surface of the coating film was triacetylcellulose (TAC). It was covered with a film (trade name “TDY80” manufactured by FUJIFILM Corporation) to obtain a laminated body (TAC / UV-3400 / liquid crystal layer / PVA / PEN layer structure). Next, 600 mJ / cm 2 of ultraviolet light (however, the amount of light measured at a wavelength of 365 nm) is irradiated from above the obtained laminate with a high-pressure mercury lamp lamp to cure the acrylic resin coating film. Thereafter, the substrate film (PVA / PEN film) was peeled from the laminate to obtain a liquid crystal film (TAC / UV-3400 / layer structure of liquid crystal layer).
　調製例１で得られた液晶フィルム（ホメオトロピック配向の液晶層／ＣＯＰフィルム）の代わりに、上述のようにして得られた液晶フィルム（ＴＡＣ／ＵＶ－３４００／液晶層の層構成）を用いた以外は、実施例１と同様にして、液晶層上にハードコート層を形成し、光学フィルム（ＴＡＣ／ＵＶ－３４００／液晶層／ハードコート層の層構成）を得た。なお、液晶層の配向状態をクロスニコルで観察したところ、液晶層がホモジニアス配向の状態で固定化されていることが確認された。 Instead of the liquid crystal film (homeotropic alignment liquid crystal layer / COP film) obtained in Preparation Example 1, the liquid crystal film (TAC / UV-3400 / layer configuration of liquid crystal layer) obtained as described above was used. Except for the above, a hard coat layer was formed on the liquid crystal layer in the same manner as in Example 1 to obtain an optical film (TAC / UV-3400 / liquid crystal layer / hard coat layer layer structure). When the alignment state of the liquid crystal layer was observed with crossed Nicols, it was confirmed that the liquid crystal layer was fixed in a homogeneous alignment state.
　（比較例４）
　先ず、調製例１で採用した方法と同様の方法を採用して溶液状態の液晶材料（液晶性組成物）を調製した。次に、ラビング処理を行ったポリビニルアルコール／ポリエチレンナフタレート（ＰＶＡ／ＰＥＮ：なお、ＰＶＡは日本酢ビポバール株式会社製の商品名「ＰＸＰ－０５」を使用し、ＰＥＮは帝人株式会社製の商品名「テオネックス　Ｑ５１」を使用）の積層体からなる基板フィルムのＰＶＡ層上に、前記溶液状態の液晶材料を塗工し、得られた塗膜を６０℃のホットプレートで１０分乾燥した後に、前記乾燥後の塗膜と基板フィルム（ＰＶＡ／ＰＥＮフィルム）との積層物に対して、１４５℃のオーブンを用いて１分間の熱処理を施し、一度、オーブンから熱処理後の積層物を取り出して室温（２５℃）まで冷却した後、かかる冷却後の積層物に対して、１２５℃のオーブンを用いて１分３０秒間の熱処理を施すことにより前記塗膜（液晶層）を形成する液晶材料を配向させて、液晶材料がスプレー配向した塗膜（膜厚１．１μｍ）を備える積層体を得た。次いで、前記液晶材料がスプレー配向した塗膜を備える積層体を、６０℃に加熱したアルミ板上に密着させて置き、その上から、高圧水銀灯ランプにより、６００ｍＪ／ｃｍ２の紫外光（ただし、３６５ｎｍの波長の光を測定した光量）を照射して、前記配向処理後の塗膜（液晶層）を硬化させて、配向状態を固定化し、配向状態が固定化された液晶層（膜厚１．０μｍ）を備えるフィルム（液晶層／基板フィルム［ＰＶＡ／ＰＥＮ］の層構成）を得た。 (Comparative Example 4)
First, a liquid crystal material (liquid crystal composition) in a solution state was prepared by employing the same method as that employed in Preparation Example 1. Next, rubbing-treated polyvinyl alcohol / polyethylene naphthalate (PVA / PEN: PVA uses the product name “PXP-05” manufactured by Nihon Vinegar Bipoval Co., Ltd., and PEN uses the product name manufactured by Teijin Ltd. After applying the solution-state liquid crystal material on the PVA layer of the substrate film composed of a laminate of “Teonex Q51”) and drying the obtained coating film on a hot plate at 60 ° C. for 10 minutes, The laminate of the dried coating film and the substrate film (PVA / PEN film) is subjected to heat treatment for 1 minute using an oven at 145 ° C., and once the laminate after heat treatment is taken out of the oven at room temperature ( After cooling to 25 ° C.), the coated layer (liquid crystal layer) is subjected to heat treatment for 1 minute and 30 seconds using a 125 ° C. oven on the cooled laminate. ) Was aligned to obtain a laminate including a coating film (film thickness 1.1 μm) in which the liquid crystal material was spray aligned. Next, the laminate including the coating film in which the liquid crystal material is spray-oriented is placed in close contact on an aluminum plate heated to 60 ° C., and from there, a high-pressure mercury lamp lamp is used to emit 600 mJ / cm 2 ultraviolet light (however, A liquid crystal layer (film thickness 1) in which the alignment state is fixed by irradiating the coating film (liquid crystal layer) after the alignment treatment by irradiating 365 nm wavelength light). .Mu.m) (liquid crystal layer / substrate film [PVA / PEN] layer structure).
　このようにして得られたフィルムの液晶層上にＵＶ硬化型アクリル樹脂（東亞合成製ＵＶ－３４００）を塗布し、塗膜を形成した後、該塗膜の表面上をトリアセチルセルロース（ＴＡＣ）フィルム（富士フイルム株式会社製の商品名「ＴＤＹ８０」）で覆い、積層体（ＴＡＣ／ＵＶ－３４００／液晶層／ＰＶＡ／ＰＥＮの層構成）を得た。次に、得られた積層体の上から高圧水銀灯ランプにより、６００ｍＪ／ｃｍ２の紫外光（ただし、３６５ｎｍの波長の光を測定した光量）を照射して、前記アクリル樹脂の塗膜を硬化させた後、該積層体から基板フィルム（ＰＶＡ／ＰＥＮフィルム）を剥離することにより、液晶フィルム（ＴＡＣ／ＵＶ－３４００／液晶層の層構成）を得た。 A UV curable acrylic resin (UV-3400 manufactured by Toagosei Co., Ltd.) was applied on the liquid crystal layer of the film thus obtained to form a coating film, and then the surface of the coating film was triacetylcellulose (TAC). It was covered with a film (trade name “TDY80” manufactured by FUJIFILM Corporation) to obtain a laminated body (TAC / UV-3400 / liquid crystal layer / PVA / PEN layer structure). Next, 600 mJ / cm 2 of ultraviolet light (however, the amount of light measured at a wavelength of 365 nm) is irradiated from above the obtained laminate with a high-pressure mercury lamp lamp to cure the acrylic resin coating film. Thereafter, the substrate film (PVA / PEN film) was peeled from the laminate to obtain a liquid crystal film (TAC / UV-3400 / layer structure of liquid crystal layer).
　調製例１で得られた液晶フィルム（ホメオトロピック配向の液晶層／ＣＯＰフィルム）の代わりに、上述のようにして得られた液晶フィルム（ＴＡＣ／ＵＶ－３４００／液晶層）を用いた以外は、実施例１と同様にして、液晶層上にハードコート層を形成し、光学フィルム（ＴＡＣ／ＵＶ－３４００／液晶層／ハードコート層の層構成）を得た。なお、液晶層の配向状態をクロスニコルで観察したところ、液晶層がスプレー配向の状態で固定化されていることが確認された。 Except for using the liquid crystal film (TAC / UV-3400 / liquid crystal layer) obtained as described above instead of the liquid crystal film (homeotropic liquid crystal layer / COP film) obtained in Preparation Example 1, In the same manner as in Example 1, a hard coat layer was formed on the liquid crystal layer to obtain an optical film (TAC / UV-3400 / liquid crystal layer / hard coat layer layer structure). When the alignment state of the liquid crystal layer was observed with crossed Nicols, it was confirmed that the liquid crystal layer was fixed in a spray alignment state.
　［実施例及び比較例で得られた光学フィルムの特性評価］
　〈ハードコート層が光学フィルムの位相差に及ぼす影響についての評価〉
　実施例１及び比較例１で得られた光学フィルムを用いて、ハードコート層が光学フィルムの位相差に及ぼす影響を評価した。このような光学フィルムの位相差は、王子計測機器株式会社製の自動複屈折計（商品名「ＫＯＢＲＡ２１　ＡＤＨ」）を用いて測定し、各光学フィルムの表面に対して垂直方向から測定光を入射する条件と、各光学フィルムの表面に対して斜め５０度（該表面に対して測定光がなす角度）から測定光を入射する条件で、それぞれ位相差を測定した（測定回数Ｎ＝２として平均値を求めた）。得られた結果を表１に示す。 [Characteristic evaluation of optical films obtained in Examples and Comparative Examples]
<Evaluation of influence of hard coat layer on retardation of optical film>
Using the optical film obtained in Example 1 and Comparative Example 1, the effect of the hard coat layer on the retardation of the optical film was evaluated. The retardation of such an optical film is measured using an automatic birefringence meter (trade name “KOBRA21 ADH”) manufactured by Oji Scientific Instruments Co., Ltd., and measurement light is incident from the direction perpendicular to the surface of each optical film. And the phase difference was measured under the condition that the measurement light is incident at an angle of 50 degrees with respect to the surface of each optical film (the angle formed by the measurement light with respect to the surface) (average number of measurements N = 2) Value). The obtained results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
　表１に示す結果からも明らかなように、実施例１及び比較例１で得られた光学フィルムは共に、正面位相差、斜め方向（５０°）の位相差はほぼ同等の値となっており、ハードコート層を積層することによって位相差にほとんど変化がないことが認められた。このような結果から、ハードコート層の積層工程において液晶層の特性を積層前と比較して十分に維持することが可能であることが確認された。 As is clear from the results shown in Table 1, both of the optical films obtained in Example 1 and Comparative Example 1 have substantially the same front phase difference and phase difference in the oblique direction (50 °). It was confirmed that there was almost no change in the retardation by laminating the hard coat layer. From these results, it was confirmed that the characteristics of the liquid crystal layer can be sufficiently maintained in the laminating step of the hard coat layer as compared with before the laminating.
　＜光学フィルムにおける液晶層とハードコート層の層間密着力の測定＞
　実施例１及び比較例２～４で得られた各光学フィルムの層間密着力は以下のようにして測定した。すなわち、先ず、実施例等で得られた各光学フィルムをそれぞれ用い、ラミネーター（ムサシノキカイ社製）を使用してロール速度０．７５ｍ／ｍｉｎの条件で、セパレーター／粘着層／光学フィルム（基材（ＣＯＰフィルム又はＴＡＣ／ＵＶ－３４００の積層フィルム）／液晶層／ハードコート層）／セロテープ（登録商標）からなる積層サンプルをそれぞれ作成した。なお、このような粘着層の積層には、セパレーター／粘着層／セパレーターという構成を有する両面テープ（日東電工株式製の両面テープ（商品名「Ｎ５０１Ｆ」）を利用して、その両面テープの一方のセパレーターを剥がして、基材（ＣＯＰフィルム又はＴＡＣ／ＵＶ－３４００の積層フィルム）の表面上に粘着層が接するようにして利用した。また、前記セロテープ（登録商標）としては、ニチバン株式会社製の商品名「ＣＴ－１８Ｓ」を使用した（なお、セロテープ（登録商標）はハードコート層の表面上に配置した。）。このようにして得られた各積層サンプルから、それぞれ長さ１００ｍｍ、幅２５ｍｍの短冊状試料を切り出した後、短冊状試料中のセパレーターを剥がして、該試料をガラスプレパラートに貼り合せ、層間密着力の評価用の試験サンプルとした。そして、前記試験サンプルを用いて、東洋精機株式会社製の商品名「ストログラフＥ－Ｌ」により、前記試験サンプルの表面からセロテープ（登録商標）を９０°方向に剥離（セロテープ（登録商標）／ハードコート層の層間を剥離）して、前記試験サンプルの９０°剥離強度を測定（測定回数Ｎ＝３回、温度２３℃、剥離速度３００ｍｍ／ｍｉｎ）して、液晶層／ハードコート層の層間が剥離された際に加えられた力のモーメントの平均値（平均密着力）を求めて、液晶層とハードコート層との間の平均密着力を測定した。得られた結果を表２に示す。 <Measurement of interlayer adhesion between liquid crystal layer and hard coat layer in optical film>
The interlayer adhesion of each optical film obtained in Example 1 and Comparative Examples 2 to 4 was measured as follows. That is, first, using each of the optical films obtained in Examples and the like, using a laminator (manufactured by Musashinokikai Co., Ltd.) and a roll speed of 0.75 m / min, a separator / adhesive layer / optical film (base material ( COP film or TAC / UV-3400 laminated film) / liquid crystal layer / hard coat layer) / cello tape (registered trademark) were prepared. In addition, for the lamination of such an adhesive layer, a double-sided tape having a configuration of separator / adhesive layer / separator (double-sided tape manufactured by Nitto Denko Corporation (trade name “N501F”)) is used. The separator was peeled off, and the adhesive layer was in contact with the surface of the base material (COP film or TAC / UV-3400 laminated film), and the cello tape (registered trademark) was manufactured by Nichiban Co., Ltd. The trade name “CT-18S” was used (cello tape (registered trademark) was placed on the surface of the hard coat layer.) From each of the laminated samples thus obtained, the length was 100 mm and the width was 25 mm. After cutting out the strip-shaped sample, the separator in the strip-shaped sample is peeled off, and the sample is bonded to the glass preparation, and the interlayer adhesion is A test sample for evaluation was used, and using the test sample, Cellotape (registered trademark) was placed in a 90 ° direction from the surface of the test sample according to the product name “Strograph EL” manufactured by Toyo Seiki Co., Ltd. Peeling (cello tape (registered trademark) / peeling between hard coat layers) and measuring the 90 ° peel strength of the test sample (number of measurements N = 3, temperature 23 ° C., peel rate 300 mm / min), The average value of the moment of force applied when the liquid crystal layer / hard coat layer was peeled (average adhesion) was determined, and the average adhesion between the liquid crystal layer and the hard coat layer was measured. The results obtained are shown in Table 2.
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
　表２に示す結果からも明らかなように、実施例１で得られた光学フィルムにおいては、ハードコート層／ホメオトロピック配向液晶層の層間の平均密着力（ハードコート層がホメオトロピック液晶層から剥離された際に加えた力のモーメントの平均値）は４６２Ｎ／ｍ（実施例１）であり、実施例１で得られた光学フィルムにおいては、ハードコート層／ホメオトロピック液晶層の層間の密着性が十分に優れたものとなることが確認された。他方、比較例２で得られた光学フィルムにおいては、平均密着力は４３４Ｎ／ｍであることが確認された。また、比較例３及び比較例４で得られた光学フィルムにおいては、平均密着力はそれぞれ２４Ｎ／ｍおよび３５Ｎ／ｍと低く、液晶層の配向状態がホメオトロピック配向以外の状態にある場合には、ウレタン（メタ）アクリレート系樹脂を含有するハードコート材料を積層しても十分な密着性を得ることができないことも確認された。 As is apparent from the results shown in Table 2, in the optical film obtained in Example 1, the average adhesion between the hard coat layer / homeotropic alignment liquid crystal layer (the hard coat layer was peeled off from the homeotropic liquid crystal layer). (Average value of the moment of force applied) was 462 N / m (Example 1). In the optical film obtained in Example 1, the adhesion between the layers of the hard coat layer / homeotropic liquid crystal layer was Was confirmed to be sufficiently excellent. On the other hand, in the optical film obtained in Comparative Example 2, it was confirmed that the average adhesion was 434 N / m. In the optical films obtained in Comparative Examples 3 and 4, the average adhesion is as low as 24 N / m and 35 N / m, respectively, and the alignment state of the liquid crystal layer is in a state other than homeotropic alignment. It was also confirmed that sufficient adhesion could not be obtained even if a hard coat material containing a urethane (meth) acrylate resin was laminated.
　このような結果から、ハードコート層の材料にウレタン（メタ）アクリレート系樹脂を含有するハードコート材料を用いることで、ウレタン（メタ）アクリレート系樹脂以外の（メタ）アクリレート系樹脂を含有するハードコート材料と比較して、より高度な水準の密着性が達成されることが確認された。また、ウレタン（メタ）アクリレート系樹脂を含有するハードコート材料を用いた場合には、ホメオトロピック配向の液晶層に対して、特異的に、十分に高度な密着性を付与できることが確認された。 From these results, a hard coat containing a (meth) acrylate resin other than a urethane (meth) acrylate resin by using a hard coat material containing a urethane (meth) acrylate resin as the material of the hard coat layer. It was confirmed that a higher level of adhesion was achieved compared to the material. Further, it was confirmed that when a hard coat material containing a urethane (meth) acrylate resin is used, a sufficiently high adhesion can be imparted specifically and specifically to a liquid crystal layer having homeotropic alignment.
　＜鉛筆硬度の測定＞
　実施例１及び比較例１～２で得られた各光学フィルムの鉛筆硬度を測定した。すなわち、各光学フィルムをガラス板（厚さ２ｍｍ）上にテープで固定した測定サンプル（ガラス／ＣＯＰ／液晶層／ハードコート層）をそれぞれ作成した後、コーテック株式会社製の鉛筆硬度試験器（商品名「ＫＴ－ＶＦ２３８０」）を用いて、ハードコート層側の面の硬度を、１９９９年発行のＪＩＳ　Ｋ５６００－５－４に規定されている方法に準拠してそれぞれ測定することにより求めた。得られた結果を表３に示す。 <Measurement of pencil hardness>
The pencil hardness of each optical film obtained in Example 1 and Comparative Examples 1 and 2 was measured. That is, after each measurement film (glass / COP / liquid crystal layer / hard coat layer) was prepared by fixing each optical film with a tape on a glass plate (thickness 2 mm), a pencil hardness tester (product) Using the name “KT-VF2380”), the hardness of the surface on the hard coat layer side was determined by measuring each according to the method defined in JIS K5600-5-4 issued in 1999. The obtained results are shown in Table 3.
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
　表３に示す結果からも明らかなように、ハードコート層を利用した場合（実施例１、比較例２）においては鉛筆硬度が４Ｂであるのに対して、ハードコート層を利用しなかった場合（比較例１）には鉛筆硬度が６Ｂ以下であり、ハードコート層を利用することで硬化度が十分に増加することが確認された。 As is clear from the results shown in Table 3, when the hard coat layer was used (Example 1, Comparative Example 2), the pencil hardness was 4B, whereas the hard coat layer was not used. In (Comparative Example 1), the pencil hardness was 6B or less, and it was confirmed that the degree of curing sufficiently increased by using the hard coat layer.
　また、ハードコート層を積層した本発明の光学フィルム（実施例１）と、ハードコート層を積層していない比較のための光学フィルム（比較例１）とに対してそれぞれクリーニングクロス（クラレ社製の商品名「クリネスタ」）を用い、前記クリーニングクロスを荷重７５０ｇとなるような負荷をかけながら、各光学フィルムの表面（基材と反対側の表面）上を１０回往復させて、その後、各光学フィルムの表面の傷の状態を偏光顕微鏡にて確認した。その結果、比較のための光学フィルム（比較例１）においては液晶層に直接傷が発生したのに対して、本発明の光学フィルム（実施例１）においては、ハードコート層に傷がついても、傷が液晶層に達することはなく、ハードコート層により液晶層に傷がつくことが十分に防止されていることが確認された。 Further, cleaning cloths (manufactured by Kuraray Co., Ltd.) for the optical film of the present invention (Example 1) laminated with a hard coat layer and an optical film for comparison (Comparative Example 1) not laminated with a hard coat layer, respectively. Product name “Crinesta”), while applying a load of 750 g on the cleaning cloth, the surface of each optical film (surface opposite to the substrate) was reciprocated 10 times, The state of scratches on the surface of the optical film was confirmed with a polarizing microscope. As a result, in the optical film for comparison (Comparative Example 1), the liquid crystal layer was directly scratched, whereas in the optical film of the present invention (Example 1), the hard coat layer was scratched. It was confirmed that the scratch did not reach the liquid crystal layer, and the hard coat layer sufficiently prevented the liquid crystal layer from being scratched.
　＜耐熱性の測定＞
　実施例１及び比較例１～２で得られた各光学フィルムの耐熱性を評価するために、先ず、各光学フィルムをそれぞれ３ｃｍ×４ｃｍの長方形サイズにカットしたサンプルを作成し、該サンプル中のハードコート層の表面に、厚み２５μｍの粘着剤層とセパレーターフィルムとの積層体（一般的なＬＣＤグレードのノンキャリア糊）を貼り合わせ、次いで、セパレーターフィルムを剥離し、ガラス板（２ｍｍ厚）に貼り付けてガラス／粘着剤層／ハードコート層／ホメオトロピック液晶層／ＣＯＰフィルムの順に積層された耐熱性評価用の試料を得た。なお、このような試料の調整方法と同様の方法を採用して、熱処理を施す前と後のホメオトロピック液晶層の状態を比較評価するために、熱処理を施さないブランクサンプルも準備した。そして、前記耐熱性評価用の試料に対しては、ドライオーブン（トーマス科学器械株式会社製の「パイルアップオーブンＴＡＨ－２１Ｈ」中、９０℃、乾燥条件下で加熱する熱処理を施した（総加熱時間：５１５時間）。 <Measurement of heat resistance>
In order to evaluate the heat resistance of each optical film obtained in Example 1 and Comparative Examples 1 and 2, first, a sample was prepared by cutting each optical film into a rectangular size of 3 cm × 4 cm. A laminate of a 25 μm thick adhesive layer and a separator film (general LCD grade non-carrier glue) is bonded to the surface of the hard coat layer, and then the separator film is peeled off to form a glass plate (2 mm thick). A sample for heat resistance evaluation was obtained, which was laminated and laminated in the order of glass / adhesive layer / hard coat layer / homeotropic liquid crystal layer / COP film. A blank sample without heat treatment was also prepared in order to compare and evaluate the state of the homeotropic liquid crystal layer before and after heat treatment by adopting a method similar to such a sample preparation method. Then, the heat resistance evaluation sample was subjected to a heat treatment in a dry oven (“Pile-up oven TAH-21H” manufactured by Thomas Scientific Instruments Co., Ltd.) under a dry condition at 90 ° C. (total heating Time: 515 hours).
　このようにして得られた熱処理後の試料と、熱処理を施していない試料（ブランクサンプル）の位相差（厚み方向のリターデーション：Ｒｔｈ）をそれぞれ測定し、ブランクサンプルに対する熱処理後の試料のＲｔｈの変動率（％）を測定し、かかるＲｔｈの変動率に基づいて、耐熱性を評価した。なお、Ｒｔｈの変動率の測定に際して、前記熱処理の加熱時間を２４時間、１４４時間、３１２時間、５１５時間とした段階で前記試料の厚み方向のリターデーション（Ｒｔｈ）をそれぞれ測定して、各熱処理時間経過後の試料のＲｔｈをそれぞれ求めた。また、位相差は、王子計測機器株式会社製の自動複屈折計（商品名「ＫＯＢＲＡ２１　ＡＤＨ」）を用い、波長５９０ｎｍ光を用いて測定した。得られた結果を表４及び図１に示す。 The phase difference (retardation in the thickness direction: Rth) between the heat-treated sample thus obtained and the non-heat-treated sample (blank sample) is measured, and the Rth of the sample after heat treatment with respect to the blank sample is measured. The variation rate (%) was measured, and the heat resistance was evaluated based on the variation rate of Rth. When measuring the variation rate of Rth, the thickness direction retardation (Rth) of the sample was measured at the stage where the heating time of the heat treatment was 24 hours, 144 hours, 312 hours, and 515 hours. The Rth of the sample after the passage of time was determined. The phase difference was measured using an automatic birefringence meter (trade name “KOBRA21 ADH”) manufactured by Oji Scientific Instruments Co., Ltd., using light having a wavelength of 590 nm. The obtained results are shown in Table 4 and FIG.
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
　表４及び図１に示す結果からも明らかなように、本発明の光学フィルム（実施例１）においては、５１５時間加熱した後においてもＲｔｈの変動率が－１．７８％であるのに対して、ハードコート層を積層していない場合（比較例１）及びハードコート層を積層していてもハードコート材料がウレタン（メタ）アクリレート系樹脂を含まないものである場合（比較例２）には、それぞれ、５１５時間加熱した後のＲｔｈの変動率が－４．２９％（比較例１）、－３．０５％（比較例２）であることが確認された。このような結果から、ウレタン（メタ）アクリレート系樹脂を含むハードコート材料を硬化して得られたハードコート層を備える場合（実施例１）には、熱によるＲｔｈの変動を非常に高度な水準で抑制できることが確認され、熱により、ホメオトロピック配向の液晶層の配向状態が変化することを十分に抑制できることが確認された。 As is apparent from the results shown in Table 4 and FIG. 1, in the optical film of the present invention (Example 1), the variation rate of Rth is −1.78% even after heating for 515 hours. When the hard coat layer is not laminated (Comparative Example 1) and when the hard coat material does not contain a urethane (meth) acrylate resin even if the hard coat layer is laminated (Comparative Example 2) It was confirmed that the fluctuation rates of Rth after heating for 515 hours were −4.29% (Comparative Example 1) and −3.05% (Comparative Example 2), respectively. From these results, when a hard coat layer obtained by curing a hard coat material containing a urethane (meth) acrylate resin is provided (Example 1), the Rth variation due to heat is a very high level. It was confirmed that the change of the alignment state of the homeotropic liquid crystal layer due to heat can be sufficiently suppressed.
　上述のような測定結果から、本発明（実施例１）によれば、液晶層とハードコート層との間の密着性を十分に高度なものとすることができ、そのハードコート層により液晶層に十分な耐傷性を付与できるばかりか、液晶層に十分に優れた耐熱性を付与できるため、品質の劣化（熱や傷による劣化）が十分に抑制された光学フィルムが得られることが確認された。 From the measurement results as described above, according to the present invention (Example 1), the adhesion between the liquid crystal layer and the hard coat layer can be made sufficiently high, and the liquid crystal layer is formed by the hard coat layer. In addition to being able to impart sufficient scratch resistance to the liquid crystal layer, it has been confirmed that an optical film with sufficiently suppressed quality deterioration (deterioration due to heat and scratches) can be obtained because it can impart sufficiently excellent heat resistance to the liquid crystal layer. It was.
　以上説明したように、本発明によれば、ホメオトロピック配向の液晶層とハードコート層との間の密着性を十分に高度なものとすることができ、十分に高度な耐傷性を有するとともに、十分に優れた耐熱性を有し、熱により液晶層の配向状態が変化することを十分に抑制することが可能な光学フィルム及びその製造方法を提供することが可能となる。 As described above, according to the present invention, the adhesion between the homeotropic alignment liquid crystal layer and the hard coat layer can be sufficiently advanced, and has a sufficiently high scratch resistance, It is possible to provide an optical film having sufficiently excellent heat resistance and capable of sufficiently suppressing the change in the alignment state of the liquid crystal layer due to heat, and a method for producing the same.
　したがって、本発明の光学フィルムは、各種画像表示装置に用いるための光学素子（例えば偏光板、位相差フィルム等）に利用するための材料等として特に有用である。 Therefore, the optical film of the present invention is particularly useful as a material for use in an optical element (for example, a polarizing plate, a retardation film, etc.) for use in various image display devices.

Claims (7)

  1. 　基材と、前記基材上に積層された液晶層と、前記液晶層上に積層されたハードコート層とを備える光学フィルムであって、
    　前記液晶層が液晶材料をホメオトロピック配向の状態で固定化した層であり、且つ、前記ハードコート層がウレタン（メタ）アクリレート系樹脂を含むハードコート材料を硬化してなる層である、光学フィルム。     An optical film comprising a base material, a liquid crystal layer laminated on the base material, and a hard coat layer laminated on the liquid crystal layer,
    An optical film in which the liquid crystal layer is a layer in which a liquid crystal material is fixed in a homeotropic alignment state, and the hard coat layer is a layer formed by curing a hard coat material containing a urethane (meth) acrylate resin .
  2. 　前記ハードコート層の厚みが０．１～５μｍである、請求項１に記載の光学フィルム。 2. The optical film according to claim 1, wherein the hard coat layer has a thickness of 0.1 to 5 μm.
  3. 　前記液晶材料がポリ（メタ）アクリレート系液晶ポリマーを含有する、請求項１又は２に記載の光学フィルム。 The optical film according to claim 1 or 2, wherein the liquid crystal material contains a poly (meth) acrylate-based liquid crystal polymer.
  4. 　前記基材が環状オレフィンポリマーからなる、請求項１～３のうちのいずれか一項に記載の光学フィルム。 The optical film according to any one of claims 1 to 3, wherein the substrate is made of a cyclic olefin polymer.
  5. 　請求項１～４のうちのいずれか一項に記載の光学フィルムを備える、偏光板。 A polarizing plate comprising the optical film according to any one of claims 1 to 4.
  6. 　請求項５に記載の偏光板を備える、画像表示装置。 An image display device comprising the polarizing plate according to claim 5.
  7. 　基材上に液晶材料をホメオトロピック配向の状態で固定化した液晶層を積層した後、前記液晶層上にウレタン（メタ）アクリレート系樹脂を含むハードコート材料を塗布し、硬化することによりハードコート層を積層し、
    　前記基材と、前記基材上に積層された前記液晶層と、前記液晶層上に積層された前記ハードコート材料を硬化してなる前記ハードコート層とを備える光学フィルムを得る、光学フィルムの製造方法。     After laminating a liquid crystal layer in which a liquid crystal material is fixed in a homeotropic alignment state on a base material, a hard coat material containing a urethane (meth) acrylate resin is applied on the liquid crystal layer and cured to hard coat. Laminating layers,
    An optical film comprising: the base material; the liquid crystal layer laminated on the base material; and the hard coat layer formed by curing the hard coat material laminated on the liquid crystal layer. Production method.
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