WO2021079773A1 - Phase difference film, method for manufacturing same; and circularly polarizing plate and image display device using said phase difference film - Google Patents

Phase difference film, method for manufacturing same; and circularly polarizing plate and image display device using said phase difference film Download PDF

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WO2021079773A1
WO2021079773A1 PCT/JP2020/038470 JP2020038470W WO2021079773A1 WO 2021079773 A1 WO2021079773 A1 WO 2021079773A1 JP 2020038470 W JP2020038470 W JP 2020038470W WO 2021079773 A1 WO2021079773 A1 WO 2021079773A1
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group
resin
retardation film
film
structural unit
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PCT/JP2020/038470
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French (fr)
Japanese (ja)
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寛教 柳沼
清水　享
中西　貞裕
敏行 飯田
慎悟 並木
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日東電工株式会社
三菱ケミカル株式会社
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Priority to KR1020217026557A priority Critical patent/KR102580448B1/en
Priority to CN202080017294.2A priority patent/CN113544552B/en
Priority to SG11202107851QA priority patent/SG11202107851QA/en
Publication of WO2021079773A1 publication Critical patent/WO2021079773A1/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
    • G02B5/3083—Birefringent or phase retarding elements
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/8791—Arrangements for improving contrast, e.g. preventing reflection of ambient light
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D11/00—Producing optical elements, e.g. lenses or prisms
    • B29D11/00634—Production of filters
    • B29D11/00644—Production of filters polarizing
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
    • C08L33/04—Homopolymers or copolymers of esters
    • C08L33/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
    • C08L33/10—Homopolymers or copolymers of methacrylic acid esters
    • C08L33/12—Homopolymers or copolymers of methyl methacrylate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L69/00—Compositions of polycarbonates; Compositions of derivatives of polycarbonates
    • 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
    • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
    • 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
    • G02B1/08—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of polarising materials
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/13363—Birefringent elements, e.g. for optical compensation
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/50—OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements

Definitions

  • the present invention relates to a retardation film and a method for producing the same, and a circular polarizing plate and an image display device using the retardation film.
  • a retardation film showing a so-called inverse dispersion wavelength dependence in which the retardation value increases according to the wavelength of the measurement light (hereinafter, simply reverse). (Sometimes referred to as a dispersed retardation film) is under development. In the development of the inverse dispersion retardation film, continuous studies are being carried out to further improve the characteristics.
  • a main object of the present invention is to provide a reverse dispersion retardation film having excellent extensibility and phase difference expression and having a small haze.
  • the retardation film of the present invention is represented by at least one bonding group selected from the group consisting of carbonate bonds and ester bonds, structural units represented by the following general formula (1), and the following general formula (2). It contains at least one structural unit selected from the group consisting of structural units, and contains a resin having a positive refractive index anisotropy; an acrylic resin; The content of the acrylic resin is 0.5% by mass to 2.0% by mass. The acrylic resin contains 70% by mass or more of a structural unit derived from methyl methacrylate, and its weight average molecular weight Mw is 10,000 to 200,000. Further, the Re (550) of the retardation film is 100 nm to 200 nm, and the Re (450) / Re (550) is more than 0.5 and less than 1.0.
  • R 1 to R 3 are independently bonded, substituted or unsubstituted alkylene groups having 1 to 4 carbon atoms, and R 4 to R 9 are independent of each other.
  • Hydrogen atom substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted aryl group having 4 to 10 carbon atoms, substituted or unsubstituted acyl group having 1 to 10 carbon atoms, substituted or unsubstituted.
  • Substituted alkoxy group with 1-10 carbon atoms substituted or unsubstituted aryloxy group with 1-10 carbon atoms, substituted or unsubstituted amino group, substituted or unsubstituted vinyl group with 1-10 carbon atoms, substituted or unsubstituted It is an unsubstituted ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; however, R 4 to R 9 are the same as each other.
  • Re (550) is the in-plane phase difference of the film measured with light having a wavelength of 550 nm at 23 ° C.
  • Re (450) is the in-plane phase difference of the film measured with light having a wavelength of 450 nm at 23 ° C.
  • the resin having positive refractive index anisotropy is selected from the group consisting of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2). Contains 1% by mass to 40% by mass of at least one structural unit.
  • the resin having a positive refractive index anisotropy further includes a structural unit represented by the following general formula (3). In one embodiment, the resin having positive refractive index anisotropy further includes a structural unit represented by the following general formula (4).
  • the retardation film has a haze value of 1.5% or less. In one embodiment, the retardation film has a breaking elongation of 200% or more. In one embodiment, the retardation film has a limit birefringence ⁇ n of 0.0039 or more. According to another aspect of the present invention, there is provided a method for producing the above retardation film.
  • This production method includes stretching a resin film containing the resin having a positive refractive index anisotropy and the acrylic resin, and the stretching includes stretching the resin having a positive refractive index anisotropy. It is carried out at a temperature equal to or lower than the glass transition temperature. In one embodiment, the stretching is performed while transporting the elongated resin film in the elongated direction, and the delayed axial direction of the obtained elongated retardation film is relative to the elongated direction. The direction is 40 ° to 50 ° or 130 ° to 140 °. According to yet another aspect of the present invention, a circularly polarizing plate is provided.
  • This circularly polarizing plate has a polarizer and the above-mentioned retardation film, and the angle formed by the absorption axis of the polarizer and the slow axis of the retardation film is 40 ° to 50 ° or 130 ° to 140 °. Is.
  • an image display device is provided. This image display device is provided with the above-mentioned circularly polarizing plate on the viewing side, and the polarizer of the circularly polarizing plate is arranged on the viewing side.
  • a resin having a specific positive refractive index anisotropy typically, a polycarbonate resin, a polyester resin or a polyester carbonate resin
  • an acrylic resin typically, a polycarbonate resin, a polyester resin or a polyester carbonate resin
  • Refractive index (nx, ny, nz) "Nx" is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and "ny” is the in-plane direction orthogonal to the slow-phase axis (that is, the phase-advance axis direction). Is the refractive index of, and "nz” is the refractive index in the thickness direction.
  • In-plane phase difference (Re) “Re ( ⁇ )” is the in-plane phase difference of the film measured with light having a wavelength of ⁇ nm at 23 ° C.
  • Re (450) is an in-plane phase difference of a film measured with light having a wavelength of 450 nm at 23 ° C.
  • Phase difference in the thickness direction (Rth) is a phase difference in the thickness direction of the film measured with light having a wavelength of ⁇ nm at 23 ° C.
  • Rth (450) is the phase difference in the thickness direction of the film measured with light having a wavelength of 450 nm at 23 ° C.
  • the retardation film according to the embodiment of the present invention contains a resin containing at least one bonding group selected from the group consisting of carbonate bonds and ester bonds.
  • the retardation film contains a polycarbonate-based resin, a polyester-based resin, or a polyester carbonate-based resin (hereinafter, these may be collectively referred to as a polycarbonate-based resin or the like).
  • the polycarbonate-based resin or the like contains at least one structural unit selected from the group consisting of the structural unit represented by the general formula (1) and / or the structural unit represented by the general formula (2). These structural units are structural units derived from divalent oligofluorene, and may be hereinafter referred to as oligofluorene structural units.
  • Such polycarbonate-based resins and the like have positive refractive index anisotropy.
  • the retardation film further contains an acrylic resin.
  • the content of the acrylic resin is 0.5% by mass to 1.5% by mass.
  • the percentage or part of "mass” unit is synonymous with the percentage or part of "weight” unit.
  • the oligofluorene structural unit is represented by the above general formula (1) or (2).
  • R 1 to R 3 are independently bonded, substituted or unsubstituted alkylene groups having 1 to 4 carbon atoms, and R 4 to R 9 are independent of each other.
  • Substituted alkoxy group with 1-10 carbon atoms substituted or unsubstituted aryloxy group with 1-10 carbon atoms, substituted or unsubstituted amino group, substituted or unsubstituted vinyl group with 1-10 carbon atoms, substituted or unsubstituted It is an unsubstituted ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group.
  • R 4 to R 9 may be the same or different from each other, and at least two adjacent groups of R 4 to R 9 may be bonded to each other to form a ring.
  • R 1 and R 2 for example, the following alkylene groups can be adopted: linear alkylene groups such as methylene group, ethylene group, n-propylene group, n-butylene group; methylmethylene group, dimethyl. Methylene group, ethylmethylene group, propylmethylene group, (1-methylethyl) methylene group, 1-methylethylene group, 2-methylethylene group, 1-ethylethylene group, 2-ethylethylene group, 1-methylpropylene group, An alkylene group having a branched chain such as a 2-methylpropylene group, a 1,1-dimethylethylene group, a 2,2-dimethylpropylene group, or a 3-methylpropylene group.
  • the positions of the branched chains in R 1 and R 2 are indicated by numbers assigned so that the carbon on the fluorene ring side is at the 1st position.
  • R 1 and R 2 may be related to the development of inverse dispersion wavelength dependence.
  • Polycarbonate-based resins and the like show the strongest inverse dispersion wavelength dependence when the fluorene ring is oriented perpendicular to the main chain direction (stretching direction).
  • R 1 and R 2 having 2 to 3 carbon atoms on the main chain of the alkylene group should be adopted. Is preferable. When the number of carbon atoms is 1, unexpectedly, the inverse dispersion wavelength dependence may not be shown.
  • the orientation of the fluorene ring is fixed in a direction that is not perpendicular to the main chain direction due to steric hindrance of the carbonate group and / or ester group that are the linking groups of the oligofluorene structural unit. Conceivable.
  • the orientation of the fluorene ring is weakly fixed, and the inverse dispersion wavelength dependence may be insufficient. Further, the heat resistance of the polycarbonate resin or the like may decrease.
  • the R 3, for example, can be adopted an alkylene group of the following: a methylene group, an ethylene group, n- propylene, n- linear alkylene group such as a butylene group; a methylmethylene group, dimethylmethylene group, Ethylmethylene group, propylmethylene group, (1-methylethyl) methylene group, 1-methylethylene group, 2-methylethylene group, 1-ethylethylene group, 2-ethylethylene group, 1-methylpropylene group, 2-methyl An alkylene group having a branched chain such as a propylene group, a 1,1-dimethylethylene group, a 2,2-dimethylpropylene group, or a 3-methylpropylene group.
  • R 3 preferably has 1 to 2 carbon atoms on the main chain of the alkylene group, and more preferably 1 carbon atom.
  • the immobilization of the fluorene ring is weakened as in the case of R 1 and R 2 , and the inverse dispersion wavelength dependence is reduced, the photoelastic coefficient is increased, the heat resistance is decreased, and the like. There is a risk of inviting.
  • the smaller the number of carbon atoms on the main chain the better the optical characteristics and heat resistance, but if the 9-positions of the two fluorene rings are directly connected by a direct bond, the thermal stability may deteriorate.
  • Examples of the substituent in R 1 to R 3 include a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom); an alkoxy group having 1 to 10 carbon atoms such as a methoxy group and an ethoxy group; an acetyl group and a benzoyl group.
  • a halogen atom fluorine atom, chlorine atom, bromine atom or iodine atom
  • an alkoxy group having 1 to 10 carbon atoms such as a methoxy group and an ethoxy group
  • an acetyl group and a benzoyl group an alkoxy group having 1 to 10 carbon atoms
  • the substituted or unsubstituted alkyl group in R 4 to R 9 for example, the following alkyl groups can be adopted: methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, Linear alkyl groups such as n-hexyl and n-decyl; alkyl groups having branched chains such as isopropyl group, 2-methylpropyl group, 2,2-dimethylpropyl group and 2-ethylhexyl group; cyclopropyl group, Cyclic alkyl group such as cyclopentyl group, cyclohexyl group, cyclooctyl group.
  • the number of carbon atoms of the alkyl group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained.
  • substituent of the alkyl group include the above-mentioned substituents for R 1 to R 3.
  • the substituted or unsubstituted aryl group in R 4 to R 9 for example, the following aryl group can be adopted: an aryl group such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group; a 2-pyridyl group. , 2-thienyl group, 2-furyl group and other heteroaryl groups.
  • the aryl group preferably has 8 or less carbon atoms, and more preferably 7 or less carbon atoms. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained.
  • the substituent of the aryl group include the above-mentioned substituents for R 1 to R 3.
  • acyl groups can be adopted: formyl group, acetyl group, propionyl group, 2-methylpropionyl group, 2,2-dimethylpropionyl.
  • Group aliphatic acyl group such as 2-ethylhexanoyl group; aromatic acyl group such as benzoyl group, 1-naphthylcarbonyl group, 2-naphthylcarbonyl group, 2-furylcarbonyl group.
  • the number of carbon atoms of the acyl group is preferably 4 or less, and more preferably 2 or less.
  • the substituted or unsubstituted alkoxy group or aryloxy group in R 4 to R 9 for example, the following can be adopted: methoxy group, ethoxy group, isopropoxy group, tert-butoxy group, trifluoromethoxy group, Phenoxy group.
  • the number of carbon atoms of the alkoxy group or the aryloxy group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained.
  • the substituent of the alkoxy group or the aryloxy group include the above-mentioned substituents for R 1 to R 3.
  • amino group N-methylamino group, N, N-dimethylamino group, N-ethylamino.
  • An aliphatic group such as a group, N, N-diethylamino group, N, N-methylethylamino group, N-propylamino group, N, N-dipropylamino group, N-isopropylamino group, N, N-diisopropylamino group.
  • Aromatic amino group such as N-phenylamino group, N, N-diphenylamino group; Acylamino group such as formamide group, acetamide group, decanoylamide group, benzoylamide group, chloroacetamide group; benzyloxycarbonylamino Group, alkoxycarbonylamino group such as tert-butyloxycarbonylamino group.
  • N, N-dimethylamino group, N-ethylamino group, or N, N-diethylamino group is preferable, and N, N-dimethylamino group is more preferable. They do not have highly acidic protons, have a small molecular weight, and can increase the fluorene ratio.
  • the substituted or unsubstituted vinyl group or ethynyl group in R 4 to R 9 for example, the following can be adopted: vinyl group, 2-methylvinyl group, 2,2-dimethylvinyl group, 2-phenylvinyl. Group, 2-acetylvinyl group, ethynyl group, methylethynyl group, tert-butylethynyl group, phenylethynyl group, acetylethynyl group, trimethylsilylethynyl group.
  • the vinyl group or ethynyl group preferably has 4 or less carbon atoms.
  • sulfur-containing groups can be adopted: sulfo group; alkyl such as methyl sulfonyl group, ethyl sulfonyl group, propyl sulfonyl group, isopropyl sulfonyl group and the like.
  • Sulfonyl group arylsulfonyl group such as phenylsulfonyl group and p-tolylsulfonyl group; alkylsulfinyl group such as methylsulfinyl group, ethylsulfinyl group, propylsulfinyl group and isopropylsulfinyl group; Arylsulfinyl groups; alkylthio groups such as methylthio groups and ethylthio groups; arylthio groups such as phenylthio groups and p-tolylthio groups; alkoxysulfonyl groups such as methoxysulfonyl groups and ethoxysulfonyl groups; aryloxysulfonyl groups such as phenoxysulfonyl groups; amino Sulfonyl groups; N-methylaminosulfonyl groups, N-ethylaminosulfon
  • the sulfo group may form a salt with lithium, sodium, potassium, magnesium, ammonium or the like.
  • a methylsulfinyl group, an ethylsulfinyl group, or a phenylsulfinyl group is preferable, and a methylsulfinyl group is more preferable. They do not have highly acidic protons, have a small molecular weight, and can increase the fluorene ratio.
  • the silicon atom having a substituent in R 4 to R 9 for example, the following silyl groups can be adopted: a trialkylsilyl group such as a trimethylsilyl group and a triethylsilyl group; a trimethoxysilyl group and a triethoxysilyl group. Such as trialkoxysilyl groups.
  • a trialkylsilyl group is preferred. This is because it is excellent in stability and handleability.
  • the content of the oligofluorene structural unit in the polycarbonate resin or the like is preferably 1% by mass to 40% by mass, more preferably 10% by mass to 35% by mass, and further preferably 15% by mass with respect to the entire resin. It is% to 30% by mass, and particularly preferably 18% by mass to 25% by mass. If the content of the oligofluorene structural unit is too large, problems such as an excessively large photoelastic coefficient, insufficient reliability, and insufficient phase difference expression may occur. Furthermore, since the proportion of oligofluorene structural units in the resin is high, the range of molecular design is narrowed, and it may be difficult to improve the resin when modification is required.
  • Examples of the method for adjusting the ratio of the oligofluorene structural unit in the resin include a method of copolymerizing a monomer having an oligofluorene structural unit with another monomer, and a method of copolymerizing a resin containing an oligofluorene structural unit with another resin. There is a method of blending. Since the content of oligofluorene structural units can be precisely controlled, high transparency can be obtained, and uniform properties can be obtained over the entire surface of the film, a monomer having oligofluorene structural units can be copolymerized with another monomer. The method of doing is preferable.
  • Polycarbonate-based resins and the like may typically contain other structural units in addition to the oligofluorene structural units.
  • the other structural unit may preferably be derived from a dihydroxy compound or a diester compound.
  • the oligofluorene structural unit having negative intrinsic birefringence and the structural unit having positive intrinsic birefringence into the polymer structure.
  • a dihydroxy compound or a diester compound which is a raw material of a structural unit having positive birefringence is more preferable.
  • Examples of the copolymerization monomer include a compound into which a structural unit containing an aromatic ring can be introduced and a compound in which a structural unit containing an aromatic ring is not introduced, that is, a compound having an aliphatic structure. Specific examples of the compound having the aliphatic structure are given below.
  • Ethylene glycol 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-heptanediol, 1,6-hexane
  • Dihydroxy compounds of linear aliphatic hydrocarbons such as diols, 1,9-nonanediols, 1,10-decanediols and 1,12-dodecanediols; dihydroxys of branched aliphatic hydrocarbons such as neopentyl glycols and hexylene glycols.
  • Oxyalkylene glycols such as glycols; dihydroxy compounds having a cyclic ether structure such as isosorbide; dihydroxy compounds having a cyclic acetal structure such as spiroglycol and dioxane glycol; 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, Alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelli acid, suberic acid, azelaic acid and sebacic acid.
  • Aromatic bisphenol compound 2,2-bis (4- (2-hydroxyethoxy) phenyl) propane, 2,2-bis (4- (2-hydroxypropoxy) phenyl) propane, 1,3-bis (2-hydroxy) Dihydroxy compound having an ether group bonded to an aromatic group such as ethoxy) benzene, 4,4'-bis (2-hydroxyethoxy) biphenyl, bis (4- (2-hydroxyethoxy) phenyl) sulfone; terephthalic acid, phthalic acid.
  • Aromatic dicarboxylic acids such as acids, 4,4'-benzophenonedicarboxylic acids, 4,4'-diphenoxyetanedicarboxylic acids, 4,4'-diphenylsulfonedicarboxylic acids, and 2,6-naphthalenedicarboxylic acids.
  • the aliphatic dicarboxylic acid and the aromatic dicarboxylic acid component mentioned above can be used as a raw material for the polyester carbonate as the dicarboxylic acid itself, but a dicarboxylic acid such as a methyl ester or a phenyl ester can be used depending on the production method.
  • Dicarboxylic acid derivatives such as esters and dicarboxylic acid halides can also be used as raw materials.
  • Dihydroxy compounds having a fluorene ring such as hydroxyphenyl) fluorene and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, and dicarboxylic acid compounds having a fluorene ring can also be used in combination with oligofluorene compounds.
  • the resin used in the present invention is a structural unit other than the oligofluorene structural unit that does not contain an aromatic component. That is, it is preferable to use a compound having an aliphatic structure as the copolymerization monomer.
  • the inclusion of aromatic components in the main chain of the polymer cancels out the inverse wavelength dispersibility developed by the oligofluorene structural units, which requires an increase in the content of the oligofluorene structural units, thereby light.
  • the elastic coefficient and mechanical properties may deteriorate.
  • the other structural unit that does not contain an aromatic component it is possible to prevent the aromatic component from being incorporated into the main chain due to the structural unit.
  • the compounds having an aliphatic structure a compound having an alicyclic structure having excellent mechanical properties and heat resistance is more preferable.
  • the content of the structural unit containing an aromatic group (excluding the oligofluorene structural unit) in the resin is preferably 5% by mass or less.
  • the resin used in the present invention preferably contains a structural unit represented by the following formula (3) as a copolymerization component among the structural units that can be introduced by the compound having an alicyclic structure.
  • Spiroglycol can be used as the dihydroxy compound into which the structural unit of the formula (3) can be introduced.
  • the structural unit represented by the formula (3) is preferably contained in an amount of 5% by mass or more and 90% by mass or less.
  • the upper limit is more preferably 70% by mass or less, and particularly preferably 50% by mass or less.
  • the lower limit is more preferably 10% by mass or more, more preferably 20% by mass or more, and particularly preferably 25% by mass or more.
  • the resin used in the present invention preferably further contains a structural unit represented by the following formula (4) as a copolymerization component.
  • dihydroxy compound into which the structural unit represented by the above formula (4) can be introduced examples include isosorbide (ISB), isomannide, and isoidet, which are in a stereoisomeric relationship. These may be used individually by 1 type, and may be used in combination of 2 or more type.
  • the structural unit represented by the formula (4) is preferably contained in an amount of 5% by mass or more and 90% by mass or less.
  • the upper limit is more preferably 70% by mass or less, and particularly preferably 50% by mass or less.
  • the lower limit is more preferably 10% by mass or more, and particularly preferably 15% by mass or more.
  • the structural unit represented by the formula (4) has a characteristic of high water absorption, if the content of the structural unit represented by the formula (4) is equal to or less than the upper limit, the molded product by water absorption The dimensional change can be suppressed within an allowable range.
  • the resin used in the present invention may contain still another structural unit.
  • such a structural unit may be referred to as "another structural unit”.
  • 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, and 1,4-cyclohexanedicarboxylic acid (and its derivatives) are more preferable, and 1,4-cyclohexanedimethanol is more preferable.
  • Methanol and tricyclodecanedimethanol are particularly preferred.
  • Resins containing structural units derived from these monomers have an excellent balance of optical properties, heat resistance, mechanical properties, and the like. Further, since the polymerization reactivity of the diester compound is relatively low, it is preferable not to use a diester compound other than the diester compound containing an oligofluorene structural unit from the viewpoint of increasing the reaction efficiency.
  • the dihydroxy compound or diester compound for introducing other structural units may be used alone or in combination of two or more, depending on the required performance of the obtained resin.
  • the content of other structural units in the resin is preferably 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and particularly preferably 10% by mass or more and 30% by mass or less.
  • Other structural units play a role in adjusting the heat resistance of the resin and imparting flexibility and toughness. Therefore, if the content is too low, the mechanical properties and melt processability of the resin deteriorate, and the content is too high. As a result, heat resistance and optical characteristics may deteriorate.
  • the molecular weight of the polycarbonate resin can be expressed, for example, by the reduced viscosity.
  • the reduced viscosity is measured by using methylene chloride as a solvent, precisely adjusting the concentration of the polycarbonate resin to 0.6 g / dL, and using a Ubbelohde viscous tube at a temperature of 20.0 ° C. ⁇ 0.1 ° C.
  • the lower limit of the reduction viscosity is usually preferably 0.30 dL / g or more, more preferably 0.35 dL / g or more, and particularly preferably 0.40 dL / g or more.
  • the upper limit of the reduction viscosity is usually preferably 1.00 dL / g or less, more preferably 0.80 dL / g or less, and particularly preferably 0.60 dL / g or less. If the reduced viscosity is less than the lower limit, the mechanical strength of the obtained film may be insufficient. On the other hand, if the reduced viscosity is larger than the upper limit, moldability, handleability and productivity may be insufficient.
  • the melt viscosity of the polycarbonate resin is preferably 700 Pa ⁇ s or more and 5000 Pa ⁇ s or less under the measurement conditions of a temperature of 240 ° C. and a shear rate of 91.2 sec -1.
  • the upper limit is more preferably 4000 Pa ⁇ s or less, more preferably 3500 Pa ⁇ s or less, and particularly preferably 3000 Pa ⁇ s or less.
  • the lower limit is more preferably 1000 Pa ⁇ s or more, more preferably 1500 Pa ⁇ s or more, and particularly preferably 2000 Pa ⁇ s or more.
  • the melt viscosity is measured using a capillary rheometer (manufactured by Toyo Seiki Co., Ltd.).
  • the glass transition temperature (Tg) of the resin used in the present invention is preferably 110 ° C. or higher and 160 ° C. or lower.
  • the upper limit is more preferably 155 ° C. or lower, more preferably 150 ° C. or lower, and particularly preferably 145 ° C. or lower.
  • the lower limit is more preferably 120 ° C. or higher, and particularly preferably 130 ° C. or higher. If the glass transition temperature is out of the above range, the heat resistance tends to deteriorate, which may cause a dimensional change after film molding or deteriorate the reliability of quality under the usage conditions of the retardation film. On the other hand, if the glass transition temperature is excessively high, unevenness in the film thickness may occur during film molding, the film may become brittle, the stretchability may deteriorate, and the transparency of the film may be impaired.
  • composition and manufacturing method of the polycarbonate resin and the like are described in, for example, International Publication No. 2015/159928 pamphlet. This description is incorporated herein by reference.
  • Acrylic resin an acrylic resin as a thermoplastic resin is used.
  • the monomer that becomes the structural unit of the acrylic resin include the following compounds: methyl methacrylate, methacrylic acid, methyl acrylate, acrylic acid, benzyl (meth) acrylate, n-butyl (meth) acrylate.
  • two or more kinds of monomers may be used alone or in combination of two or more.
  • examples of the form in which two or more kinds of monomers are used in combination include copolymerization of two or more kinds of monomers, two or more blends of homopolymers of one kind of monomer, and combinations thereof.
  • other monomers copolymerizable with these acrylic monomers for example, olefin-based monomers and vinyl-based monomers may be used in combination.
  • Acrylic resin contains structural units derived from methyl methacrylate.
  • the content of the structural unit derived from methyl methacrylate in the acrylic resin is preferably 70% by mass or more and 100% by mass or less.
  • the lower limit is more preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 95% by mass or more. Within this range, excellent compatibility with the polycarbonate resin of the present invention can be obtained.
  • As the structural unit other than methyl methacrylate it is preferable to use methyl acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, and styrene. Thermal stability can be improved by copolymerizing methyl acrylate.
  • the refractive index of the acrylic resin can be adjusted by using phenyl (meth) acrylate, benzyl (meth) acrylate, and styrene
  • the transparency of the obtained resin composition can be adjusted by adjusting to the refractive index of the combined resin.
  • the sex can be improved.
  • the weight average molecular weight Mw of the acrylic resin is 10,000 or more and 200,000 or less.
  • the lower limit is preferably 30,000 or more, and particularly preferably 50,000 or more.
  • the upper limit is preferably 180,000 or less, and particularly preferably 150,000 or less.
  • the above weight average molecular weight is a polystyrene-equivalent molecular weight measured by GPC. The details of the measurement method will be described later. Further, it is preferable that the acrylic resin does not substantially contain a branched structure from the viewpoint of compatibility. The fact that it does not contain a branched structure can be confirmed by the fact that the GPC curve of the acrylic resin is monomodal.
  • A-1-3 Blending of Polycarbonate Resin, etc. and Acrylic Resin Polycarbonate Resin, etc. and Acrylic Resin are blended and used as a resin composition in a method for producing a retardation film (the production method will be described later in Section A-3).
  • the polycarbonate-based resin or the like and the acrylic-based resin can preferably be blended in a molten state.
  • a typical method for blending in a molten state is melt kneading using an extruder.
  • the kneading temperature is preferably 200 ° C. to 280 ° C., more preferably 220 ° C. to 270 ° C., and even more preferably 230 ° C. to 260 ° C.
  • pellets of a resin composition in which both resins are uniformly blended can be obtained while suppressing thermal decomposition. If the temperature of the molten resin in the extruder exceeds 280 ° C., coloration and / or thermal decomposition of the resin may occur. On the other hand, if the temperature of the molten resin in the extruder is lower than 200 ° C., the viscosity of the resin may become too high and an excessive load may be applied to the extruder, or the resin may be insufficiently melted. Any appropriate configuration can be adopted as the configuration of the extruder, the configuration of the screw, and the like.
  • twin-screw extruder it is preferable to use a twin-screw extruder in order to obtain transparency of the resin that can withstand the application of optical films. Furthermore, the residual low molecular weight components in the resin and the low molecular weight thermal decomposition components during extrusion kneading may contaminate the cooling rolls and transport rolls in the film forming process and the drawing process, so that they can be removed. , It is preferable to use an extruder equipped with a vacuum vent.
  • the content of the acrylic resin in the resin composition (as a result, the retardation film) is 0.5% by mass or more and 2.0% by mass or less as described above.
  • the lower limit is more preferably 0.6% by mass or more.
  • the upper limit is preferably 1.5% by mass or less, more preferably 1.0% by mass or less, further preferably 0.9% by mass or less, and particularly preferably 0.8% by mass or less.
  • the resin composition contains aromatic polycarbonate, aliphatic polycarbonate, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic, amorphous polyolefin, for the purpose of modifying properties such as mechanical properties and / or solvent resistance.
  • Synthetic resins such as ABS, AS, polylactic acid, polybutylene succinate, rubber, and combinations thereof may be further blended.
  • the resin composition may further contain additives.
  • additives include heat stabilizers, antioxidants, catalyst deactivators, ultraviolet absorbers, light stabilizers, mold release agents, dye pigments, impact improvers, antistatic agents, lubricants, lubricants, and plasticizers.
  • agents include agents, compatibilizers, nucleating agents, flame retardants, inorganic fillers and effervescent agents.
  • the type, number, combination, content, etc. of the additives contained in the resin composition can be appropriately set according to the purpose.
  • the in-plane retardation Re (550) of the retardation film is 100 nm to 200 nm, preferably 110 nm to 180 nm, more preferably 120 nm to 160 nm, and further preferably 130 nm to 130 nm as described above. It is 150 nm. That is, the retardation film can function as a so-called ⁇ / 4 plate.
  • the retardation film typically satisfies the relationship of Re (450) ⁇ Re (550) ⁇ Re (650). That is, the retardation film exhibits a wavelength dependence of inverse dispersion in which the retardation value increases according to the wavelength of the measurement light.
  • the Re (450) / Re (550) of the retardation film is more than 0.5 and less than 1.0 as described above, preferably 0.7 to 0.95, and more preferably 0.75 to 0.75. It is 0.92, more preferably 0.8 to 0.9.
  • Re (650) / Re (550) is preferably 1.0 or more and less than 1.15, and more preferably 1.03 to 1.1.
  • the retardation film Since the retardation film has an in-plane retardation as described above, it has a relationship of nx> ny.
  • the retardation film exhibits any suitable index of refraction ellipsoid as long as it has an nx> ny relationship.
  • the refractive index ellipsoid of the retardation film typically shows a relationship of nx> ny ⁇ nz.
  • the Nz coefficient of the retardation film is preferably 0.9 to 2.0, more preferably 0.9 to 1.5, and even more preferably 0.9 to 1.2. By satisfying such a relationship, a very excellent reflected hue can be achieved when a circularly polarizing plate including a retardation film is used in an image display device.
  • the thickness of the retardation film can be set so that it can function most appropriately as a ⁇ / 4 plate.
  • the thickness can be set to obtain the desired in-plane phase difference.
  • the thickness is preferably 15 ⁇ m to 60 ⁇ m, more preferably 20 ⁇ m to 55 ⁇ m, and most preferably 20 ⁇ m to 45 ⁇ m. According to the embodiment of the present invention, since a retardation film having excellent retardation expression can be obtained, the thickness of the retardation film can be remarkably reduced as compared with a normal ⁇ / 4 plate.
  • the haze value of the retardation film is preferably 1.5% or less, more preferably 1.0% or less, and further preferably 0.5% or less. According to the embodiment of the present invention, it is possible to realize a reverse dispersion retardation film excellent in both retardation expression and haze value. The smaller the haze value, the more preferable. The lower limit of the haze value can be, for example, 0.1%.
  • the elongation at break of the retardation film is preferably 200% or more, more preferably 210% or more, further preferably 220% or more, and particularly preferably 245% or more.
  • the upper limit of elongation at break can be, for example, 500%. Since the retardation film according to the embodiment of the present invention is excellent in extensibility in addition to being excellent in phase difference expression, a desired in-plane retardation is realized with a very thin thickness by these synergistic effects. obtain.
  • breaking elongation means the elongation rate at the time of breaking of a film in fixed-end uniaxial stretching at a predetermined stretching temperature (for example, Tg-2 ° C.).
  • the limit birefringence ⁇ n of the retardation film is preferably 0.0039 or more, more preferably 0.0040 or more, still more preferably 0.0041 or more, and particularly preferably 0.0044 or more.
  • the upper limit of the limit birefringence ⁇ n can be, for example, 0.0070.
  • "limit birefringence” means birefringence at the maximum stretching ratio which does not break when the stretching ratio is increased at a predetermined stretching temperature. Birefringence can be obtained by dividing the in-plane retardation Re of the film at the maximum unbreakable draw ratio by the film thickness d.
  • the absolute value of the photoelastic coefficient of the retardation film is preferably 20 ⁇ 10-12 (m 2 / N) or less, more preferably 1.0 ⁇ 10-12 (m 2 / N) to 15 ⁇ 10. It is -12 (m 2 / N), more preferably 2.0 ⁇ 10 -12 (m 2 / N) to 12 ⁇ 10 -12 (m 2 / N).
  • the absolute value of the photoelastic coefficient is in such a range, display unevenness can be suppressed when the retardation film is applied to an image display device.
  • Method for producing a retardation film The retardation film according to the above items A-1 and A-2 can be obtained by forming a film from the resin composition according to the item A-1 and further stretching the film. ..
  • any suitable molding processing method can be adopted. Specific examples include a compression molding method, a transfer molding method, an injection molding method, an extrusion molding method, a blow molding method, a powder molding method, an FRP molding method, a cast coating method (for example, a casting method), a calendar molding method, and a hot press. Law etc. can be mentioned. Of these, an extrusion molding method or a cast coating method, which can improve the smoothness of the obtained film and obtain good optical uniformity, is preferable.
  • the extrusion molding method particularly the melt extrusion molding method using a T-die, is particularly preferable from the viewpoint of film productivity and ease of subsequent stretching treatment.
  • the molding conditions can be appropriately set according to the composition and type of the resin used, the characteristics desired for the retardation film, and the like. In this way, a resin film containing a polycarbonate-based resin or the like and an acrylic-based resin can be obtained.
  • the thickness of the resin film can be set to an arbitrary appropriate value according to the desired thickness of the obtained retardation film, desired optical characteristics, stretching conditions described later, and the like. It is preferably 50 ⁇ m to 300 ⁇ m.
  • any appropriate stretching method and stretching conditions for example, stretching temperature, stretching ratio, stretching direction
  • various stretching methods such as free-end stretching, fixed-end stretching, free-end contraction, and fixed-end contraction can be used alone or simultaneously or sequentially.
  • the stretching direction it can be performed in various directions and dimensions such as a length direction, a width direction, a thickness direction, and an oblique direction.
  • a retardation film having the desired optical characteristics for example, refractive index characteristics, in-plane retardation, Nz coefficient
  • the retardation film is produced by uniaxially stretching or fixed end uniaxially stretching the resin film.
  • the uniaxial stretching include a method of stretching the resin film in the traveling direction (long direction) while traveling in the elongated direction.
  • Specific examples of the fixed-end uniaxial stretching include a method of stretching the resin film in the width direction (lateral direction) while running the resin film in the long direction.
  • the draw ratio is preferably 1.1 times to 3.5 times.
  • the retardation film can be produced by continuously obliquely stretching a long resin film in a direction of a predetermined angle with respect to the long direction.
  • a long stretched film having an orientation angle (delayed axis in the direction of a predetermined angle) at a predetermined angle with respect to the long direction of the film can be obtained, for example, with a polarizer.
  • Roll-to-roll is possible at the time of laminating, and the manufacturing process can be simplified.
  • the predetermined angle may be an angle formed by the absorption axis of the polarizer and the slow axis of the retardation film in the circularly polarizing plate (described later).
  • the angle is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, still more preferably 44 ° to 46 °, and particularly preferably about 45 °; as described below; It is preferably 130 ° to 140 °, more preferably 132 ° to 138 °, still more preferably 134 ° to 136 °, and particularly preferably about 135 °.
  • Examples of the stretching machine used for diagonal stretching include a tenter type stretching machine capable of applying a feeding force, a pulling force, or a pulling force at different speeds in the horizontal and / or vertical directions.
  • the tenter type stretching machine includes a horizontal uniaxial stretching machine, a simultaneous biaxial stretching machine, and the like, but any suitable stretching machine can be used as long as the long resin film can be continuously and diagonally stretched.
  • Examples of the method of diagonal stretching include JP-A-50-83482, JP-A-2-113920, JP-A-3-182701, JP-A-2000-9912, and JP-A-2002-86554. Examples thereof include the methods described in JP-A-2002-22944.
  • the stretching temperature of the film is a temperature equal to or lower than the glass transition temperature (Tg) of a polycarbonate resin or the like.
  • Tg glass transition temperature
  • a film such as a polycarbonate resin
  • the film is in a glass state at a temperature of Tg or less, so that stretching is practically impossible.
  • an acrylic resin typically, polymethylmethacrylate
  • stretching at Tg or less can be performed without substantially changing the Tg of the polycarbonate resin or the like. It will be possible.
  • stretching at Tg or less it is possible to realize a reverse dispersion retardation film having excellent extensibility and phase difference expression and having a small haze.
  • the stretching temperature is preferably Tg to Tg-10 ° C, more preferably Tg to Tg-8 ° C, and even more preferably Tg to Tg-5 ° C.
  • the film can be appropriately stretched even at a temperature higher than Tg as long as it is, for example, about Tg + 5 ° C., and for example, about Tg + 2 ° C.
  • the intrinsic birefringence of a single acrylic resin is almost zero, the intrinsic birefringence of the resin composition is reduced by blending the acrylic resin, and the orientation birefringence developed by stretching is reduced. Is expected.
  • the blending amount of the acrylic resin is very small, it has succeeded in improving the stretching strength of the resin composition while suppressing the influence of the decrease in the intrinsic birefringence due to the acrylic resin to almost zero. It is considered that the orientation birefringence was improved.
  • FIG. 1 is a schematic cross-sectional view of a circularly polarizing plate according to one embodiment of the present invention.
  • the circularly polarizing plate 100 of the illustrated example has a polarizing plate 10 and a retardation film 20.
  • the retardation film 20 is a retardation film according to the embodiment of the present invention according to the above item A.
  • the polarizing plate 10 includes a polarizer 11, a first protective layer 12 arranged on one side of the polarizer 11, and a second protective layer 13 arranged on the other side of the polarizer 11.
  • first protective layer 12 and the second protective layer 13 may be omitted.
  • the second protective layer 13 may be omitted.
  • the angle formed by the slow axis of the retardation film 20 and the absorption axis of the polarizer 11 is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, and even more preferably 44 ° to 46 °. It is particularly preferably about 45 °; or preferably 130 ° to 140 °, more preferably 132 ° to 138 °, still more preferably 134 ° to 136 °, and particularly preferably about. It is 135 °.
  • another retardation layer 50 and / or a conductive layer or an isotropic base material 60 with a conductive layer may be provided.
  • Another retardation layer 50 and the conductive layer or the isotropic base material 60 with the conductive layer are typically provided on the outside of the retardation film 20 (opposite to the polarizing plate 10).
  • Another retardation layer 50 and the conductive layer or the isotropic base material 60 with the conductive layer are typically provided in this order from the retardation film 20 side.
  • the other retardation layer 50 and the conductive layer or the isotropic base material 60 with the conductive layer are typically arbitrary layers provided as needed, and one or both of them may be omitted.
  • the circularly polarizing plate is a so-called inner touch panel type input in which a touch sensor is incorporated between an image display cell (for example, an organic EL cell) and the polarizing plate. Can be applied to display devices.
  • the circularly polarizing plate may have an additional retardation layer.
  • the additional retardation layer may be provided in combination with another retardation layer 50, or may be provided alone (that is, without providing another retardation layer 50).
  • the optical characteristics for example, refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, and the like of the further retardation layer can be appropriately set according to the purpose.
  • the circularly polarizing plate may be single-wafered or elongated.
  • the term "long” means an elongated shape having a length sufficiently long with respect to the width, and for example, an elongated shape having a length of 10 times or more, preferably 20 times or more with respect to the width. Including.
  • the elongated circularly polarizing plate can be wound in a roll shape.
  • the polarizing plate and the retardation film are also elongated.
  • the polarizer preferably has an absorption axis in the longitudinal direction.
  • the retardation film is preferably an obliquely stretched film having a slow phase axis in a direction forming an angle of 40 ° to 50 ° or 130 ° to 140 ° with respect to the elongated direction. If the polarizer and the retardation film have such a configuration, a circularly polarizing plate can be produced by roll-to-roll.
  • an adhesive layer (not shown) is provided on the opposite side of the retardation film to the polarizing plate, and the circular polarizing plate can be attached to the image display cell. Further, it is preferable that a release film is temporarily attached to the surface of the pressure-sensitive adhesive layer until the circularly polarizing plate is used. By temporarily attaching the release film, the pressure-sensitive adhesive layer can be protected and a roll of a circularly polarizing plate can be formed.
  • any suitable polarizer can be adopted.
  • the resin film forming the polarizer may be a single-layer resin film or a laminated body having two or more layers.
  • the polarizer composed of a single-layer resin film include a hydrophilic polymer film such as a polyvinyl alcohol (PVA) -based film, a partially formalized PVA-based film, and an ethylene / vinyl acetate copolymer system partially saponified film.
  • a hydrophilic polymer film such as a polyvinyl alcohol (PVA) -based film, a partially formalized PVA-based film, and an ethylene / vinyl acetate copolymer system partially saponified film.
  • PVA polyvinyl alcohol
  • a partially formalized PVA-based film ethylene / vinyl acetate copolymer system partially saponified film
  • examples thereof include those which have been dyed and stretched with a bicolor substance such as iodine or a bicolor dye, and polyene-based oriented films such as a dehydrated product of PVA and a dehydrogenated product of polyvinyl chloride.
  • the above-mentioned dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous iodine solution.
  • the draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. Alternatively, it may be stretched and then dyed. If necessary, the PVA-based film is subjected to a swelling treatment, a cross-linking treatment, a washing treatment, a drying treatment and the like.
  • the polarizer obtained by using the laminate include a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material and the resin.
  • Examples thereof include a polarizer obtained by using a laminate with a PVA-based resin layer coated and formed on a base material.
  • the polarizer obtained by using the laminate of the resin base material and the PVA-based resin layer coated and formed on the resin base material is, for example, a resin base material obtained by applying a PVA-based resin solution to the resin base material and drying the resin base material.
  • stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Further, stretching may further include, if necessary, stretching the laminate in the air at a high temperature (eg, 95 ° C. or higher) prior to stretching in boric acid aqueous solution.
  • a high temperature eg, 95 ° C. or higher
  • the obtained resin base material / polarizer laminate may be used as it is (that is, the resin base material may be used as a protective layer for the polarizer), and the resin base material is peeled off from the resin base material / polarizer laminate. Then, an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface. Details of the method for producing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The description of these patent documents is incorporated herein by reference.
  • the thickness of the polarizer is preferably 15 ⁇ m or less, more preferably 1 ⁇ m to 12 ⁇ m, further preferably 3 ⁇ m to 10 ⁇ m, and particularly preferably 3 ⁇ m to 8 ⁇ m.
  • the thickness of the polarizer is in such a range, curling during heating can be satisfactorily suppressed, and good appearance durability during heating can be obtained. Further, if the thickness of the polarizer is in such a range, it can contribute to the thinning of the circularly polarizing plate (as a result, the organic EL display device).
  • the polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm.
  • the simple substance transmittance of the polarizer is preferably 43.0% to 46.0%, more preferably 44.5% to 46.0%.
  • the degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.
  • the first protective layer 12 and the second protective layer 13 are each formed of any suitable film that can be used as a protective layer for the polarizer.
  • the material that is the main component of the film include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and polysulfone-based. , Polystyrene-based, polycarbonate-based, polyolefin-based, (meth) acrylic-based, acetate-based transparent resins and the like.
  • TAC triacetyl cellulose
  • polyester-based polyvinyl alcohol-based
  • polycarbonate-based polyamide-based
  • polyimide-based polyimide-based
  • polyethersulfone-based polysulfone-based
  • thermosetting resins such as (meth) acrylic, urethane, (meth) acrylic urethane, epoxy, and silicone, or ultraviolet curable resins can also be mentioned.
  • glassy polymers such as siloxane-based polymers can also be mentioned.
  • the polymer film described in JP-A-2001-343529 (WO01 / 37007) can also be used.
  • a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain.
  • the polymer film can be, for example, an extruded product of the above resin composition.
  • the circularly polarizing plate is typically arranged on the visible side of the image display device, and the first protective layer 12 is typically arranged on the visible side. Therefore, the first protective layer 12 may be subjected to surface treatment such as hard coat treatment, antireflection treatment, anti-sticking treatment, and anti-glare treatment, if necessary. Further / or, if necessary, the first protective layer 12 is provided with a process for improving visibility when visually recognizing through polarized sunglasses (typically, a (elliptical) circularly polarized light function is imparted. (Giving an ultra-high phase difference) may be applied. By performing such a process, excellent visibility can be realized even when the display screen is visually recognized through a polarized lens such as polarized sunglasses. Therefore, the circularly polarizing plate can be suitably applied to an image display device that can be used outdoors.
  • polarized sunglasses typically, a (elliptical) circularly polarized light function is imparted.
  • the thickness of the first protective layer is typically 300 ⁇ m or less, preferably 100 ⁇ m or less, more preferably 5 ⁇ m to 80 ⁇ m, and even more preferably 10 ⁇ m to 60 ⁇ m.
  • the thickness of the outer protective layer is the thickness including the thickness of the surface treatment layer.
  • the second protective layer 13 is preferably optically isotropic in one embodiment.
  • optically isotropic means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is -10 nm to +10 nm.
  • the circularly polarizing plate according to item B above can be applied to an image display device. Therefore, the embodiment of the present invention also includes an image display device using such a circularly polarizing plate. Typical examples of the image display device include a liquid crystal display device and an organic EL display device.
  • the image display device according to the embodiment of the present invention includes the circularly polarizing plate according to the above item B on the visual side thereof. The circularly polarizing plate is arranged so that the polarizer is on the viewing side.
  • the glass transition temperature of the resin was measured using a differential scanning calorimeter DSC6220 manufactured by SII Nanotechnology. About 10 mg of a resin sample was placed in an aluminum pan manufactured by the same company, sealed, and heated from 30 ° C. to 200 ° C. at a heating rate of 20 ° C./min under a nitrogen stream of 50 mL / min. After maintaining the temperature for 3 minutes, it was cooled to 30 ° C. at a rate of 20 ° C./min. The temperature was maintained at 30 ° C. for 3 minutes, and the temperature was raised again to 200 ° C. at a rate of 20 ° C./min.
  • the outer glass transition start temperature which is the temperature at the intersection of the above, was determined and used as the glass transition temperature.
  • the refractive index of each wavelength was n C , using a multi-wavelength Abbe refractive index meter DR-M4 / 1550 manufactured by Atago Co., Ltd. n D and n F were measured. The measurement was carried out at 20 ° C. using monobromonaphthalene as the interface liquid.
  • Photoelasticity A device that combines a birefringence measuring device consisting of a He-Ne laser, a polarizer, a compensator, an analyzer, and a photodetector and a viscoelastic measuring device (DVE-3 manufactured by Rheology) is used. (For details, refer to Journal of the Society of Rheology, Vol. 19, p93-97 (1991)). A sample having a width of 5 mm and a length of 20 mm was cut out from the film produced by the same method as in (5) above, fixed to a viscoelasticity measuring device, and the storage elastic modulus E'was measured at a room temperature of 25 ° C. at a frequency of 96 Hz. did.
  • the emitted laser light is passed through the polarizer, the sample, the compensator, and the analyzer in this order, picked up by a photodetector (photon), and passed through a lock-in amplifier for the amplitude and distortion of the waveform with an angular frequency of ⁇ or 2 ⁇ .
  • the phase difference was obtained, and the strain optical coefficient O'was obtained.
  • the directions of the absorption axes of the polarizer and the analyzer were adjusted so as to be orthogonal to each other and to form an angle of ⁇ / 4 with respect to the extension direction of the sample.
  • the photoelastic coefficient C was obtained from the following equation using the storage elastic modulus E'and the strain optical coefficient O'.
  • C O'/ E'
  • Phase difference value of retardation film A sample of 50 mm ⁇ 50 mm was cut out from the retardation film obtained in Examples and Comparative Examples and used as a measurement sample. Re (450) and Re (550) were measured using Axoscan manufactured by Axometrics for this measurement sample. The measurement temperature was 23 ° C.
  • the in-plane retardation Re and the film thickness d of the film at the maximum unbreakable draw ratio were measured, and the in-plane retardation Re was divided by the film thickness d to obtain the limit birefringence ⁇ n.
  • the film thickness was measured with a dial gauge as described above.
  • the in-plane phase difference Re was measured using "Axoscan" manufactured by Axometrics. The measurement wavelength was 590 nm.
  • ISB Isosorbide [Rocket Foil]
  • SPG Spiroglycol [manufactured by Mitsubishi Gas Chemical Company, Inc.]
  • DPC Diphenyl carbonate [manufactured by Mitsubishi Chemical Holdings, Inc.]
  • BPEF 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene [manufactured by Osaka Gas Chemical Co., Ltd.]
  • -PEG1000 Polyethylene glycol, number average molecular weight 1000 [manufactured by Sanyo Chemical Industries, Ltd.]
  • Example 1 Polymerization was carried out using a batch polymerization apparatus consisting of two vertical stirring reactors equipped with a stirring blade and a reflux condenser.
  • BPFM is 30.31 parts by mass (0.047 mol)
  • ISB is 39.94 parts by mass (0.273 mol)
  • SPG is 30.20 parts by mass (0.099 mol)
  • DPC is 69.67 parts by mass (0.325 mol).
  • 7.88 ⁇ 10 -4 parts by mass (4.47 ⁇ 10 -6 mol) of calcium acetate monohydrate was charged as a catalyst. After substituting nitrogen under reduced pressure in the reactor, heating was performed with a heat medium, and stirring was started when the internal temperature reached 100 ° C. The internal temperature was brought to 220 ° C.
  • PC1 This resin is referred to as "PC1".
  • the reduced viscosity of PC1 is 0.46 dL / g, Mw 48,000, refractive index n D is 1.526, a melt viscosity of 2480Pa ⁇ s, a glass transition temperature of 139 ° C., the photoelastic coefficient of 9 ⁇ 10 -12 [ m 2 / N] and the wavelength dispersion Re (450) / Re (550) were 0.85.
  • BR80 as an acrylic resin
  • extrusion kneading with the obtained polyester carbonate was performed.
  • a mixture of polycarbonate pellets (99.5 parts by mass) and BR80 powder (0.5 parts by mass) was put into a twin-screw extruder TEX30HSS manufactured by Japan Steel Works, Ltd. using a quantitative feeder.
  • the extruder cylinder temperature was set to 250 ° C., and extrusion was performed at a processing rate of 12 kg / hr and a screw rotation speed of 120 rpm. Further, the extruder is equipped with a vacuum vent, and the molten resin is extruded while devolatile under reduced pressure.
  • the pellets of the resin composition thus obtained are vacuum-dried at 100 ° C.
  • the retardation film obtained at a stretching temperature of Tg and a stretching magnification of 2.4 times exhibited a refractive index characteristic of nx> ny> nz.
  • the Re (550) of the obtained retardation film was 145 nm, the Re (450) / Re (550) was 0.85, and the haze was 0.3%. The results are shown in Table 1.
  • Example 2 A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 0.7% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 3 A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 0.9% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 4 A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 1.5% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 1 A retardation film was produced in the same manner as in Example 1 except that an acrylic resin was not used (that is, the content of the acrylic resin was set to zero) and the stretching temperature was set to Tg + 2 ° C. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 2 A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 0.3% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 3 A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 3.0% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • Example 4 A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 10% by mass and the stretching temperature was Tg + 2 ° C. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
  • BR85 was used as the acrylic resin, and extrusion kneading and unstretched film were produced in the same manner as in Example 1 except that the compounding ratio of BR85 was 1% by mass.
  • the unstretched film was seemingly transparent, but fine insoluble components were generated.
  • LA4285 was used as the acrylic resin, and extrusion kneading was carried out in the same manner as in Example 1 except that the blending ratio of LA4285 was 1% by mass. The pellets after kneading were cloudy.
  • Example 7 Extrusion kneading was carried out in the same manner as in Example 1 except that P570A was used as the acrylic resin and the blending ratio of P570A was 1% by mass. The pellets after kneading were cloudy.
  • Example 9 Extrusion kneading was carried out in the same manner as in Example 1 except that MS-200 was used as the acrylic resin and the blending ratio of MS-200 was 1% by mass. The pellets after kneading were cloudy.
  • Example 10 Extrusion kneading was carried out in the same manner as in Example 1 except that G9504, a non-acrylic resin, was used as the modifier resin and the blending ratio of G9504 was 1% by mass. The pellets after kneading were cloudy.
  • the reduced viscosity of PC2 is 0.35 dL / g, Mw is 36,000, refractive index nD is 1.599, melt viscosity is 3100 Pa ⁇ s, glass transition temperature is 145 ° C, and photoelastic coefficient is 30 ⁇ 10-12 [m.
  • Comparative Examples 3 and 4 in which the amount of the acrylic resin added exceeds 2.0% by mass, the haze is high, the transparency is insufficient, and if the amount of the acrylic resin added is too large, the limit birefringence is reached. On the contrary, it can be seen that it decreases. From Comparative Examples 6 to 10, the acrylic resin and the non-acrylic resin containing a large amount of components other than methyl methacrylate are not compatible with the resin of the present invention, and therefore, the resin required as an optical film is transparent. It turns out that sex cannot be obtained. In Comparative Example 8, the resin composition after extrusion was transparent, but the haze increased after stretching. This is because the polyester carbonate resin and MS-600 have similar refractive indexes, so they are transparent in appearance, but they are practically incompatible and phase-separated. It is probable that interphase separation occurred and the haze increased.
  • Example 5 (Making a polarizer) A long roll of a polyvinyl alcohol (PVA) -based resin film (manufactured by Kuraray, product name "PE3000") having a thickness of 30 ⁇ m is uniaxially stretched in the longitudinal direction so as to be 5.9 times in the longitudinal direction by a roll stretching machine at the same time.
  • a polarizer having a thickness of 12 ⁇ m was prepared by performing swelling, dyeing, cross-linking, and washing treatment, and finally performing a drying treatment. Specifically, the swelling treatment was carried out by stretching 2.2 times while treating with pure water at 20 ° C. Next, the dyeing treatment was carried out in an aqueous solution at 30 ° C.
  • the weight ratio of iodine and potassium iodide was adjusted so that the simple substance transmittance of the obtained polarizer was 45.0% and the weight ratio was 1: 7. However, it was stretched 1.4 times.
  • the cross-linking treatment adopted a two-step cross-linking treatment, and the first-step cross-linking treatment was carried out 1.2 times while being treated with an aqueous solution in which boric acid and potassium iodide were dissolved at 40 ° C.
  • the boric acid content of the aqueous solution of the first-step cross-linking treatment was 5.0% by weight, and the potassium iodide content was 3.0% by weight.
  • the second-step cross-linking treatment was carried out 1.6 times while treating with an aqueous solution in which boric acid and potassium iodide were dissolved at 65 ° C.
  • the boric acid content of the aqueous solution of the second step cross-linking treatment was 4.3% by weight, and the potassium iodide content was 5.0% by weight.
  • the washing treatment was carried out with an aqueous potassium iodide solution at 20 ° C.
  • the potassium iodide content of the aqueous solution of the washing treatment was set to 2.6% by weight.
  • the drying treatment was carried out at 70 ° C. for 5 minutes to obtain a polarizer.
  • a triacetyl cellulose film (thickness 40 ⁇ m, manufactured by Konica Minolta, trade name “KC4UYW”) is attached to one side of the above-mentioned polarizing element via a polyvinyl alcohol-based adhesive, and a polarizing plate having a protective layer / polarizer configuration is attached.
  • the organic EL panel is taken out from a commercially available organic EL display device (manufactured by Samsung, product name "Galaxy 5"), the polarizing film attached to the organic EL panel is peeled off, and instead, the circle obtained above is used. A polarizing plate was attached to obtain an image display device (organic EL display device). The obtained organic EL display device was displayed in black on the entire surface, and the image (black display screen) was visually observed. The image was good with little reflection and no unwanted coloring.
  • the retardation film of the present invention can be suitably used for a circularly polarizing plate, and the circularly polarizing plate can be suitably used for an image display device (typically, a liquid crystal display device or an organic EL display device).
  • an image display device typically, a liquid crystal display device or an organic EL display device.
  • Polarizing plate 11 Polarizer 12 First protective layer 13 Second protective layer 20
  • Phase difference film 100 Circularly polarizing plate 101 Circularly polarizing plate

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Abstract

Provided is a reciprocal dispersion phase difference film that has outstanding extensibility and phase difference expression, and also has low haze. A phase difference film according to the present invention contains: a resin that includes at least one binding group selected from the group consisting of a carbonate bond and an ester bond, includes a structural unit derived from a bivalent oligofluorene, and has positive refractive index isotropy; and an acrylic resin. The content of the acrylic resin is 0.5%–2.0% by mass. The acrylic resin contains at least 70% by mass of a structural unit derived from methyl methacrylate and has a weight-average molecular weight Mw of 10,000–200,000. Re (550) of the phase difference film is 100–200 nm, and Re (450) / Re (550) is greater than 0.5 but less than 1.0.

Description

位相差フィルムおよびその製造方法、ならびに、該位相差フィルムを用いた円偏光板および画像表示装置A retardation film and a method for manufacturing the same, and a circularly polarizing plate and an image display device using the retardation film.
　本発明は、位相差フィルムおよびその製造方法、ならびに、該位相差フィルムを用いた円偏光板および画像表示装置に関する。 The present invention relates to a retardation film and a method for producing the same, and a circular polarizing plate and an image display device using the retardation film.
　近年、スマートフォンに代表されるスマートデバイス、またデジタルサイネージやウィンドウディスプレイなどの表示装置が強い外光の下使用される機会が増加している。それに伴い、表示装置自体または表示装置に用いられるタッチパネル部やガラス基板、金属配線等の反射体による外光反射や背景の映り込み等の問題が生じている。特に、近年実用化されてきている有機エレクトロルミネッセンス（ＥＬ）表示装置は、反射性の高い金属層を有するため、外光反射や背景の映り込み等の問題を生じやすい。そこで、位相差フィルム（代表的にはλ／４板）を有する円偏光板を視認側に反射防止フィルムとして設けることにより、これらの問題を防ぐことが知られている。さらに、可視領域の各波長において良好な位相差特性を実現するために、位相差値が測定光の波長に応じて大きくなる、いわゆる逆分散の波長依存性を示す位相差フィルム（以下、単に逆分散位相差フィルムと称する場合がある）の開発が進められている。逆分散位相差フィルムの開発においては、さらなる特性改善のために継続的な検討が行われている。 In recent years, there have been increasing opportunities for smart devices such as smartphones and display devices such as digital signage and window displays to be used under strong external light. Along with this, problems such as external light reflection by the display device itself or a touch panel unit used for the display device, a glass substrate, a reflector such as metal wiring, and reflection of the background have arisen. In particular, an organic electroluminescence (EL) display device that has been put into practical use in recent years tends to cause problems such as reflection of external light and reflection of a background because it has a highly reflective metal layer. Therefore, it is known to prevent these problems by providing a circularly polarizing plate having a retardation film (typically a λ / 4 plate) as an antireflection film on the visual recognition side. Further, in order to realize good retardation characteristics at each wavelength in the visible region, a retardation film showing a so-called inverse dispersion wavelength dependence in which the retardation value increases according to the wavelength of the measurement light (hereinafter, simply reverse). (Sometimes referred to as a dispersed retardation film) is under development. In the development of the inverse dispersion retardation film, continuous studies are being carried out to further improve the characteristics.
特許第３３２５５６０号Patent No. 3325560
　本発明の主たる目的は、伸張性および位相差発現性に優れ、かつ、ヘイズの小さい逆分散位相差フィルムを提供することにある。 A main object of the present invention is to provide a reverse dispersion retardation film having excellent extensibility and phase difference expression and having a small haze.
　本発明の位相差フィルムは、カーボネート結合およびエステル結合からなる群から選択される少なくとも１つの結合基と、下記一般式（１）で表される構造単位および下記一般式（２）で表される構造単位からなる群から選択される少なくとも１つの構造単位とを含み、正の屈折率異方性を有する樹脂と；アクリル系樹脂と；を含有する。該アクリル系樹脂の含有量は０．５質量％～２．０質量％である。また、該アクリル系樹脂は、メタクリル酸メチル由来の構造単位を７０質量％以上含有し、その重量平均分子量Ｍｗは１０，０００～２００，０００である。さらに、位相差フィルムのＲｅ（５５０）は１００ｎｍ～２００ｎｍであり、Ｒｅ（４５０）／Ｒｅ（５５０）は０．５を超えて１．０未満である。
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000006
 一般式（１）および（２）中、Ｒ１～Ｒ３は、それぞれ独立に、直接結合、置換または非置換の炭素数１～４のアルキレン基であり、Ｒ４～Ｒ９は、それぞれ独立に、水素原子、置換または非置換の炭素数１～１０のアルキル基、置換または非置換の炭素数４～１０のアリール基、置換または非置換の炭素数１～１０のアシル基、置換または非置換の炭素数１～１０のアルコキシ基、置換または非置換の炭素数１～１０のアリールオキシ基、置換または非置換のアミノ基、置換または非置換の炭素数１～１０のビニル基、置換または非置換の炭素数１～１０のエチニル基、置換基を有する硫黄原子、置換基を有するケイ素原子、ハロゲン原子、ニトロ基、またはシアノ基であり；ただし、Ｒ４～Ｒ９は、互いに同一であっても、異なっていてもよく、 Ｒ４～Ｒ９のうち隣接する少なくとも２つの基が互いに結合して環を形成していてもよい。Ｒｅ（５５０）は、２３℃における波長５５０ｎｍの光で測定したフィルムの面内位相差であり、Ｒｅ（４５０）は、２３℃における波長４５０ｎｍの光で測定したフィルムの面内位相差である。
　１つの実施形態においては、上記正の屈折率異方性を有する樹脂は、上記一般式（１）で表される構造単位および上記一般式（２）で表される構造単位からなる群から選択される少なくとも１つの構造単位を１質量％～４０質量％含有する。
　１つの実施形態においては、上記正の屈折率異方性を有する樹脂は、下記一般式（３）で表される構造単位をさらに含む。
Figure JPOXMLDOC01-appb-C000007
 　１つの実施形態においては、上記正の屈折率異方性を有する樹脂は、下記一般式（４）で表される構造単位をさらに含む。
Figure JPOXMLDOC01-appb-C000008
 　１つの実施形態においては、上記位相差フィルムは、ヘイズ値が１．５％以下である。
　１つの実施形態においては、上記位相差フィルムは、破断伸びが２００％以上である。
　１つの実施形態においては、上記位相差フィルムは、限界複屈折Δｎが０．００３９以上である。
　本発明の別の局面によれば、上記位相差フィルムの製造方法が提供される。この製造方法は、上記正の屈折率異方性を有する樹脂と上記アクリル系樹脂とを含有する樹脂フィルムを延伸することを含み、該延伸は、該正の屈折率異方性を有する樹脂のガラス転移温度以下の温度で行われる。
　１つの実施形態においては、上記延伸は、長尺状の前記樹脂フィルムを長尺方向に搬送しながら行われ、得られる長尺状の位相差フィルムの遅相軸方向は、長尺方向に対して４０°～５０°または１３０°～１４０°の方向である。
　本発明のさらに別の局面によれば、円偏光板が提供される。この円偏光板は、偏光子と上記の位相差フィルムとを有し、該偏光子の吸収軸と該位相差フィルムの遅相軸とのなす角度は４０°～５０°または１３０°～１４０°である。
　本発明のさらに別の局面によれば、画像表示装置が提供される。この画像表示装置は、上記の円偏光板を視認側に備え、該円偏光板の偏光子が視認側に配置されている。 The retardation film of the present invention is represented by at least one bonding group selected from the group consisting of carbonate bonds and ester bonds, structural units represented by the following general formula (1), and the following general formula (2). It contains at least one structural unit selected from the group consisting of structural units, and contains a resin having a positive refractive index anisotropy; an acrylic resin; The content of the acrylic resin is 0.5% by mass to 2.0% by mass. The acrylic resin contains 70% by mass or more of a structural unit derived from methyl methacrylate, and its weight average molecular weight Mw is 10,000 to 200,000. Further, the Re (550) of the retardation film is 100 nm to 200 nm, and the Re (450) / Re (550) is more than 0.5 and less than 1.0.
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000006
 In the general formulas (1) and (2), R 1 to R 3 are independently bonded, substituted or unsubstituted alkylene groups having 1 to 4 carbon atoms, and R 4 to R 9 are independent of each other. , Hydrogen atom, substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted aryl group having 4 to 10 carbon atoms, substituted or unsubstituted acyl group having 1 to 10 carbon atoms, substituted or unsubstituted. Substituted alkoxy group with 1-10 carbon atoms, substituted or unsubstituted aryloxy group with 1-10 carbon atoms, substituted or unsubstituted amino group, substituted or unsubstituted vinyl group with 1-10 carbon atoms, substituted or unsubstituted It is an unsubstituted ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; however, R 4 to R 9 are the same as each other. It may be present or different, and at least two adjacent groups of R 4 to R 9 may be bonded to each other to form a ring. Re (550) is the in-plane phase difference of the film measured with light having a wavelength of 550 nm at 23 ° C., and Re (450) is the in-plane phase difference of the film measured with light having a wavelength of 450 nm at 23 ° C.
In one embodiment, the resin having positive refractive index anisotropy is selected from the group consisting of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2). Contains 1% by mass to 40% by mass of at least one structural unit.
In one embodiment, the resin having a positive refractive index anisotropy further includes a structural unit represented by the following general formula (3).
Figure JPOXMLDOC01-appb-C000007
 In one embodiment, the resin having positive refractive index anisotropy further includes a structural unit represented by the following general formula (4).
Figure JPOXMLDOC01-appb-C000008
 In one embodiment, the retardation film has a haze value of 1.5% or less.
In one embodiment, the retardation film has a breaking elongation of 200% or more.
In one embodiment, the retardation film has a limit birefringence Δn of 0.0039 or more.
According to another aspect of the present invention, there is provided a method for producing the above retardation film. This production method includes stretching a resin film containing the resin having a positive refractive index anisotropy and the acrylic resin, and the stretching includes stretching the resin having a positive refractive index anisotropy. It is carried out at a temperature equal to or lower than the glass transition temperature.
In one embodiment, the stretching is performed while transporting the elongated resin film in the elongated direction, and the delayed axial direction of the obtained elongated retardation film is relative to the elongated direction. The direction is 40 ° to 50 ° or 130 ° to 140 °.
According to yet another aspect of the present invention, a circularly polarizing plate is provided. This circularly polarizing plate has a polarizer and the above-mentioned retardation film, and the angle formed by the absorption axis of the polarizer and the slow axis of the retardation film is 40 ° to 50 ° or 130 ° to 140 °. Is.
According to yet another aspect of the present invention, an image display device is provided. This image display device is provided with the above-mentioned circularly polarizing plate on the viewing side, and the polarizer of the circularly polarizing plate is arranged on the viewing side.
　本発明の実施形態によれば、特定の正の屈折率異方性を有する樹脂（代表的には、ポリカーボネート系樹脂、ポリエステル系樹脂またはポリエステルカーボネート系樹脂）とアクリル系樹脂とを含有することにより、伸張性および位相差発現性に優れ、かつ、ヘイズの小さい逆分散位相差フィルムを得ることができる。 According to the embodiment of the present invention, by containing a resin having a specific positive refractive index anisotropy (typically, a polycarbonate resin, a polyester resin or a polyester carbonate resin) and an acrylic resin. It is possible to obtain a reverse dispersion retardation film having excellent extensibility and retardation property and having a small haze.
本発明の１つの実施形態による円偏光板の概略断面図である。It is the schematic sectional drawing of the circularly polarizing plate by one Embodiment of this invention. 本発明の別の実施形態による円偏光板の概略断面図である。It is the schematic sectional drawing of the circularly polarizing plate by another embodiment of this invention.
　以下、本発明の代表的な実施形態について説明するが、本発明はこれらの実施形態には限定されない。 Hereinafter, typical embodiments of the present invention will be described, but the present invention is not limited to these embodiments.
（用語および記号の定義）
　本明細書における用語および記号の定義は下記の通りである。
（１）屈折率（ｎｘ、ｎｙ、ｎｚ）
　「ｎｘ」は面内の屈折率が最大になる方向（すなわち、遅相軸方向）の屈折率であり、「ｎｙ」は面内で遅相軸と直交する方向（すなわち、進相軸方向）の屈折率であり、「ｎｚ」は厚み方向の屈折率である。
（２）面内位相差（Ｒｅ）
　「Ｒｅ（λ）」は、２３℃における波長λｎｍの光で測定したフィルムの面内位相差である。例えば、「Ｒｅ（４５０）」は、２３℃における波長４５０ｎｍの光で測定したフィルムの面内位相差である。Ｒｅ（λ）は、フィルムの厚みをｄ（ｎｍ）としたとき、式：Ｒｅ＝（ｎｘ－ｎｙ）×ｄによって求められる。
（３）厚み方向の位相差（Ｒｔｈ）
　「Ｒｔｈ（λ）」は、２３℃における波長λｎｍの光で測定したフィルムの厚み方向の位相差である。例えば、「Ｒｔｈ（４５０）」は、２３℃における波長４５０ｎｍの光で測定したフィルムの厚み方向の位相差である。Ｒｔｈ（λ）は、フィルムの厚みをｄ（ｎｍ）としたとき、式：Ｒｔｈ＝（ｎｘ－ｎｚ）×ｄによって求められる。
（４）Ｎｚ係数
　Ｎｚ係数は、Ｎｚ＝Ｒｔｈ／Ｒｅによって求められる。
（５）角度
　本明細書において角度に言及するときは、特に明記しない限り、当該角度は時計回りおよび反時計回りの両方の方向の角度を包含する。 (Definition of terms and symbols)
Definitions of terms and symbols herein are as follows.
(1) Refractive index (nx, ny, nz)
"Nx" is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and "ny" is the in-plane direction orthogonal to the slow-phase axis (that is, the phase-advance axis direction). Is the refractive index of, and "nz" is the refractive index in the thickness direction.
(2) In-plane phase difference (Re)
“Re (λ)” is the in-plane phase difference of the film measured with light having a wavelength of λ nm at 23 ° C. For example, "Re (450)" is an in-plane phase difference of a film measured with light having a wavelength of 450 nm at 23 ° C. Re (λ) is obtained by the formula: Re = (nx−ny) × d, where d (nm) is the thickness of the film.
(3) Phase difference in the thickness direction (Rth)
“Rth (λ)” is a phase difference in the thickness direction of the film measured with light having a wavelength of λ nm at 23 ° C. For example, "Rth (450)" is the phase difference in the thickness direction of the film measured with light having a wavelength of 450 nm at 23 ° C. Rth (λ) is obtained by the formula: Rth = (nx−nz) × d, where d (nm) is the thickness of the film.
(4) Nz coefficient The Nz coefficient is obtained by Nz = Rth / Re.
(5) Angle When referring to an angle in the present specification, the angle includes an angle in both clockwise and counterclockwise directions unless otherwise specified.
Ａ．位相差フィルム
Ａ－１．位相差フィルムの構成材料
　本発明の実施形態による位相差フィルムは、カーボネート結合およびエステル結合からなる群から選択される少なくとも１つの結合基を含む樹脂を含有する。言い換えれば、位相差フィルムは、ポリカーボネート系樹脂、ポリエステル系樹脂またはポリエステルカーボネート系樹脂（以下、これらをまとめてポリカーボネート系樹脂等と称する場合がある）を含有する。ポリカーボネート系樹脂等は、上記一般式（１）で表される構造単位および／または上記一般式（２）で表される構造単位からなる群から選択される少なくとも１つの構造単位を含む。これらの構造単位は、２価のオリゴフルオレンに由来する構造単位であり、以下、オリゴフルオレン構造単位と称する場合がある。このようなポリカーボネート系樹脂等は、正の屈折率異方性を有する。 A. Phase difference film A-1. Constituent Material of Phase Difference Film The retardation film according to the embodiment of the present invention contains a resin containing at least one bonding group selected from the group consisting of carbonate bonds and ester bonds. In other words, the retardation film contains a polycarbonate-based resin, a polyester-based resin, or a polyester carbonate-based resin (hereinafter, these may be collectively referred to as a polycarbonate-based resin or the like). The polycarbonate-based resin or the like contains at least one structural unit selected from the group consisting of the structural unit represented by the general formula (1) and / or the structural unit represented by the general formula (2). These structural units are structural units derived from divalent oligofluorene, and may be hereinafter referred to as oligofluorene structural units. Such polycarbonate-based resins and the like have positive refractive index anisotropy.
　位相差フィルムは、アクリル系樹脂をさらに含有する。アクリル系樹脂の含有量は０．５質量％～１．５質量％である。なお、本明細書において「質量」単位の百分率または部は、「重量」単位の百分率または部と同義である。 The retardation film further contains an acrylic resin. The content of the acrylic resin is 0.5% by mass to 1.5% by mass. In addition, in this specification, the percentage or part of "mass" unit is synonymous with the percentage or part of "weight" unit.
Ａ－１－１．ポリカーボネート系樹脂等
＜オリゴフルオレン構造単位＞
　オリゴフルオレン構造単位は、上記一般式（１）または（２）で表される。一般式（１）および（２）中、Ｒ１～Ｒ３は、それぞれ独立に、直接結合、置換または非置換の炭素数１～４のアルキレン基であり、Ｒ４～Ｒ９は、それぞれ独立に、水素原子、置換または非置換の炭素数１～１０のアルキル基、置換または非置換の炭素数４～１０のアリール基、置換または非置換の炭素数１～１０のアシル基、置換または非置換の炭素数１～１０のアルコキシ基、置換または非置換の炭素数１～１０のアリールオキシ基、置換または非置換のアミノ基、置換または非置換の炭素数１～１０のビニル基、置換または非置換の炭素数１～１０のエチニル基、置換基を有する硫黄原子、置換基を有するケイ素原子、ハロゲン原子、ニトロ基、またはシアノ基である。ただし、Ｒ４～Ｒ９は、互いに同一であっても、異なっていてもよく、 Ｒ４～Ｒ９のうち隣接する少なくとも２つの基が互いに結合して環を形成していてもよい。 A-1-1. Polycarbonate resin, etc. <Oligofluorene structural unit>
The oligofluorene structural unit is represented by the above general formula (1) or (2). In the general formulas (1) and (2), R 1 to R 3 are independently bonded, substituted or unsubstituted alkylene groups having 1 to 4 carbon atoms, and R 4 to R 9 are independent of each other. , Hydrogen atom, substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted aryl group having 4 to 10 carbon atoms, substituted or unsubstituted acyl group having 1 to 10 carbon atoms, substituted or unsubstituted. Substituted alkoxy group with 1-10 carbon atoms, substituted or unsubstituted aryloxy group with 1-10 carbon atoms, substituted or unsubstituted amino group, substituted or unsubstituted vinyl group with 1-10 carbon atoms, substituted or unsubstituted It is an unsubstituted ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group. However, R 4 to R 9 may be the same or different from each other, and at least two adjacent groups of R 4 to R 9 may be bonded to each other to form a ring.
　Ｒ１およびＲ２としては、例えば、以下のアルキレン基を採用することができる：メチレン基、エチレン基、ｎ－プロピレン基、ｎ－ブチレン基等の直鎖状のアルキレン基；メチルメチレン基、ジメチルメチレン基、エチルメチレン基、プロピルメチレン基、（１－メチルエチル）メチレン基、１－メチルエチレン基、２－メチルエチレン基、１－エチルエチレン基、２－エチルエチレン基、１－メチルプロピレン基、２－メチルプロピレン基、１，１－ジメチルエチレン基、２，２－ジメチルプロピレン基、３－メチルプロピレン基等の分岐鎖を有するアルキレン基。ここで、Ｒ１およびＲ２における分岐鎖の位置は、フルオレン環側の炭素が１位となるように付与した番号により示す。 As R 1 and R 2 , for example, the following alkylene groups can be adopted: linear alkylene groups such as methylene group, ethylene group, n-propylene group, n-butylene group; methylmethylene group, dimethyl. Methylene group, ethylmethylene group, propylmethylene group, (1-methylethyl) methylene group, 1-methylethylene group, 2-methylethylene group, 1-ethylethylene group, 2-ethylethylene group, 1-methylpropylene group, An alkylene group having a branched chain such as a 2-methylpropylene group, a 1,1-dimethylethylene group, a 2,2-dimethylpropylene group, or a 3-methylpropylene group. Here, the positions of the branched chains in R 1 and R 2 are indicated by numbers assigned so that the carbon on the fluorene ring side is at the 1st position.
　Ｒ１およびＲ２の選択は、逆分散波長依存性の発現に関係し得る。ポリカーボネート系樹脂等は、フルオレン環が主鎖方向（延伸方向）に対して垂直に配向した状態において、最も強い逆分散波長依存性を示す。フルオレン環の配向状態をこのような状態に近づけ、強い逆分散波長依存性を発現させるためには、アルキレン基の主鎖上の炭素数が２～３であるＲ１およびＲ２を採用することが好ましい。炭素数が１の場合は意外にも逆分散波長依存性を示さない場合がある。この要因としては、オリゴフルオレン構造単位の連結基であるカーボネート基および／またはエステル基の立体障害によって、フルオレン環の配向が主鎖方向に対して垂直ではない方向に固定化されてしまうこと等が考えられる。一方、炭素数が多すぎる場合は、フルオレン環の配向の固定が弱くなることで、逆分散波長依存性が不十分となるおそれがある。さらに、ポリカーボネート系樹脂等の耐熱性が低下する場合がある。 The choice of R 1 and R 2 may be related to the development of inverse dispersion wavelength dependence. Polycarbonate-based resins and the like show the strongest inverse dispersion wavelength dependence when the fluorene ring is oriented perpendicular to the main chain direction (stretching direction). In order to bring the orientation state of the fluorene ring closer to such a state and to develop a strong inverse dispersion wavelength dependence, R 1 and R 2 having 2 to 3 carbon atoms on the main chain of the alkylene group should be adopted. Is preferable. When the number of carbon atoms is 1, unexpectedly, the inverse dispersion wavelength dependence may not be shown. The reason for this is that the orientation of the fluorene ring is fixed in a direction that is not perpendicular to the main chain direction due to steric hindrance of the carbonate group and / or ester group that are the linking groups of the oligofluorene structural unit. Conceivable. On the other hand, when the number of carbon atoms is too large, the orientation of the fluorene ring is weakly fixed, and the inverse dispersion wavelength dependence may be insufficient. Further, the heat resistance of the polycarbonate resin or the like may decrease.
　Ｒ３としては、例えば、以下のアルキレン基を採用することができる：メチレン基、エチレン基、ｎ－プロピレン基、ｎ－ブチレン基等の直鎖状のアルキレン基；メチルメチレン基、ジメチルメチレン基、エチルメチレン基、プロピルメチレン基、（１－メチルエチル）メチレン基、１－メチルエチレン基、２－メチルエチレン基、１－エチルエチレン基、２－エチルエチレン基、１－メチルプロピレン基、２－メチルプロピレン基、１，１－ジメチルエチレン基、２，２－ジメチルプロピレン基、３－メチルプロピレン基等の分岐鎖を有するアルキレン基。Ｒ３は、アルキレン基の主鎖上の炭素数が１～２であることが好ましく、炭素数が１であることがより好ましい。主鎖上の炭素数が多すぎる場合は、Ｒ１およびＲ２の場合と同様にフルオレン環の固定化が弱まり、逆分散波長依存性の低下、光弾性係数の増加、耐熱性の低下等を招くおそれがある。一方、主鎖上の炭素数は少ない方が光学特性および耐熱性は良好であるが、二つのフルオレン環の９位が直接結合でつながる場合は熱安定性が悪化する場合がある。 The R 3, for example, can be adopted an alkylene group of the following: a methylene group, an ethylene group, n- propylene, n- linear alkylene group such as a butylene group; a methylmethylene group, dimethylmethylene group, Ethylmethylene group, propylmethylene group, (1-methylethyl) methylene group, 1-methylethylene group, 2-methylethylene group, 1-ethylethylene group, 2-ethylethylene group, 1-methylpropylene group, 2-methyl An alkylene group having a branched chain such as a propylene group, a 1,1-dimethylethylene group, a 2,2-dimethylpropylene group, or a 3-methylpropylene group. R 3 preferably has 1 to 2 carbon atoms on the main chain of the alkylene group, and more preferably 1 carbon atom. When the number of carbon atoms on the main chain is too large, the immobilization of the fluorene ring is weakened as in the case of R 1 and R 2 , and the inverse dispersion wavelength dependence is reduced, the photoelastic coefficient is increased, the heat resistance is decreased, and the like. There is a risk of inviting. On the other hand, the smaller the number of carbon atoms on the main chain, the better the optical characteristics and heat resistance, but if the 9-positions of the two fluorene rings are directly connected by a direct bond, the thermal stability may deteriorate.
　Ｒ１～Ｒ３における置換基としては、例えば、ハロゲン原子（フッ素原子、塩素原子、臭素原子またはヨウ素原子）；メトキシ基、エトキシ基等の炭素数１～１０のアルコキシ基；アセチル基、ベンゾイル基等の炭素数１～１０のアシル基；アセトアミド基、ベンゾイルアミド基等の炭素数１～１０のアシルアミノ基；ニトロ基；シアノ基；前記ハロゲン原子、前記アルコキシ基、前記アシル基、前記アシルアミノ基、前記ニトロ基、前記シアノ基等により１～３個の水素原子が置換されていてもよい、フェニル基、ナフチル基等の炭素数６～１０のアリール基。 Examples of the substituent in R 1 to R 3 include a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom); an alkoxy group having 1 to 10 carbon atoms such as a methoxy group and an ethoxy group; an acetyl group and a benzoyl group. Such as an acyl group having 1 to 10 carbon atoms; an acylamino group having 1 to 10 carbon atoms such as an acetamido group and a benzoylamide group; a nitro group; a cyano group; An aryl group having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group, wherein 1 to 3 hydrogen atoms may be substituted with the nitro group, the cyano group and the like.
　Ｒ４～Ｒ９における置換または非置換のアルキル基としては、例えば、以下のアルキル基を採用することができる：メチル基、エチル基、ｎ－プロピル基、ｎ－ブチル基、ｎ－ペンチル基、ｎ－ヘキシル、ｎ－デシル等の直鎖状のアルキル基；イソプロピル基、２－メチルプロピル基、２，２－ジメチルプロピル基、２－エチルヘキシル基等の分岐鎖を有するアルキル基；シクロプロピル基、シクロペンチル基、シクロヘキシル基、シクロオクチル基等の環状のアルキル基。アルキル基の炭素数は、４以下であることが好ましく、２以下であることがより好ましい。炭素数がこの範囲内であると、フルオレン環同士の立体障害が生じにくく、フルオレン環に由来する所望の光学特性が得られやすい。アルキル基の置換基としては、Ｒ１～Ｒ３について上記した置換基が挙げられる。 As the substituted or unsubstituted alkyl group in R 4 to R 9 , for example, the following alkyl groups can be adopted: methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, Linear alkyl groups such as n-hexyl and n-decyl; alkyl groups having branched chains such as isopropyl group, 2-methylpropyl group, 2,2-dimethylpropyl group and 2-ethylhexyl group; cyclopropyl group, Cyclic alkyl group such as cyclopentyl group, cyclohexyl group, cyclooctyl group. The number of carbon atoms of the alkyl group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained. Examples of the substituent of the alkyl group include the above-mentioned substituents for R 1 to R 3.
　Ｒ４～Ｒ９における置換または非置換のアリール基としては、例えば、以下のアリール基を採用することができる：フェニル基、１－ナフチル基、２－ナフチル基等のアリール基；２－ピリジル基、２－チエニル基、２－フリル基等のヘテロアリール基。アリール基の炭素数は、８以下であることが好ましく、７以下であることがより好ましい。炭素数がこの範囲内であると、フルオレン環同士の立体障害が生じにくく、フルオレン環に由来する所望の光学特性が得られやすい。アリール基の置換基としては、Ｒ１～Ｒ３について上記した置換基が挙げられる。 As the substituted or unsubstituted aryl group in R 4 to R 9 , for example, the following aryl group can be adopted: an aryl group such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group; a 2-pyridyl group. , 2-thienyl group, 2-furyl group and other heteroaryl groups. The aryl group preferably has 8 or less carbon atoms, and more preferably 7 or less carbon atoms. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained. Examples of the substituent of the aryl group include the above-mentioned substituents for R 1 to R 3.
　Ｒ４～Ｒ９における置換または非置換のアシル基としては、例えば、以下のアシル基を採用することができる：ホルミル基、アセチル基、プロピオニル基、２－メチルプロピオニル基、２，２－ジメチルプロピオニル基、２－エチルヘキサノイル基等の脂肪族アシル基；ベンゾイル基、１－ナフチルカルボニル基、２－ナフチルカルボニル基、２－フリルカルボニル基等の芳香族アシル基。アシル基の炭素数は、４以下であることが好ましく、２以下であることがより好ましい。炭素数がこの範囲内であると、フルオレン環同士の立体障害が生じにくく、フルオレン環に由来する所望の光学特性が得られやすい。アシル基の置換基としては、Ｒ１～Ｒ３について上記した置換基が挙げられる。 As the substituted or unsubstituted acyl group in R 4 to R 9 , for example, the following acyl groups can be adopted: formyl group, acetyl group, propionyl group, 2-methylpropionyl group, 2,2-dimethylpropionyl. Group, aliphatic acyl group such as 2-ethylhexanoyl group; aromatic acyl group such as benzoyl group, 1-naphthylcarbonyl group, 2-naphthylcarbonyl group, 2-furylcarbonyl group. The number of carbon atoms of the acyl group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained. Examples of the substituent of the acyl group include the above-mentioned substituents for R 1 to R 3.
　Ｒ４～Ｒ９における置換または非置換のアルコキシ基またはアリールオキシ基としては、例えば、以下を採用することができる：メトキシ基、エトキシ基、イソプロポキシ基、ｔｅｒｔ－ブトキシ基、トリフルオロメトキシ基、フェノキシ基。アルコキシ基またはアリールオキシ基の炭素数は、４以下であることが好ましく、２以下であることがより好ましい。炭素数がこの範囲内であると、フルオレン環同士の立体障害が生じにくく、フルオレン環に由来する所望の光学特性が得られやすい。アルコキシ基またはアリールオキシ基の置換基としては、Ｒ１～Ｒ３について上記した置換基が挙げられる。 As the substituted or unsubstituted alkoxy group or aryloxy group in R 4 to R 9 , for example, the following can be adopted: methoxy group, ethoxy group, isopropoxy group, tert-butoxy group, trifluoromethoxy group, Phenoxy group. The number of carbon atoms of the alkoxy group or the aryloxy group is preferably 4 or less, and more preferably 2 or less. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained. Examples of the substituent of the alkoxy group or the aryloxy group include the above-mentioned substituents for R 1 to R 3.
　Ｒ４～Ｒ９における置換または非置換のアミノ基としては、例えば、以下のアミノ基を採用することができる：アミノ基；Ｎ－メチルアミノ基、Ｎ，Ｎ－ジメチルアミノ基、Ｎ－エチルアミノ基、Ｎ，Ｎ－ジエチルアミノ基、Ｎ，Ｎ－メチルエチルアミノ基、Ｎ－プロピルアミノ基、Ｎ，Ｎ－ジプロピルアミノ基、Ｎ－イソプロピルアミノ基、Ｎ，Ｎ－ジイソプロピルアミノ基等の脂肪族アミノ基；Ｎ－フェニルアミノ基、Ｎ，Ｎ－ジフェニルアミノ基等の芳香族アミノ基；ホルムアミド基、アセトアミド基、デカノイルアミド基、ベンゾイルアミド基、クロロアセトアミド基等のアシルアミノ基；ベンジルオキシカルボニルアミノ基、ｔｅｒｔ－ブチルオキシカルボニルアミノ基等のアルコキシカルボニルアミノ基。Ｎ，Ｎ－ジメチルアミノ基、Ｎ－エチルアミノ基、またはＮ，Ｎ－ジエチルアミノ基が好ましく、Ｎ，Ｎ－ジメチルアミノ基がより好ましい。これらは、酸性度の高いプロトンを有さず、分子量が小さく、フルオレン比率を高めることができる。 As the substituted or unsubstituted amino group in R 4 to R 9 , for example, the following amino groups can be adopted: amino group; N-methylamino group, N, N-dimethylamino group, N-ethylamino. An aliphatic group such as a group, N, N-diethylamino group, N, N-methylethylamino group, N-propylamino group, N, N-dipropylamino group, N-isopropylamino group, N, N-diisopropylamino group. Amino group; Aromatic amino group such as N-phenylamino group, N, N-diphenylamino group; Acylamino group such as formamide group, acetamide group, decanoylamide group, benzoylamide group, chloroacetamide group; benzyloxycarbonylamino Group, alkoxycarbonylamino group such as tert-butyloxycarbonylamino group. N, N-dimethylamino group, N-ethylamino group, or N, N-diethylamino group is preferable, and N, N-dimethylamino group is more preferable. They do not have highly acidic protons, have a small molecular weight, and can increase the fluorene ratio.
　Ｒ４～Ｒ９における置換または非置換のビニル基またはエチニル基としては、例えば、以下を採用することができる：ビニル基、２－メチルビニル基、２，２－ジメチルビニル基、２－フェニルビニル基、２－アセチルビニル基、エチニル基、メチルエチニル基、ｔｅｒｔ－ブチルエチニル基、フェニルエチニル基、アセチルエチニル基、トリメチルシリルエチニル基。ビニル基またはエチニル基の炭素数は、４以下であることが好ましい。炭素数がこの範囲内であると、フルオレン環同士の立体障害が生じにくく、フルオレン環に由来する所望の光学特性が得られやすい。また、フルオレン環の共役系が長くなることにより、より強い逆分散波長依存性を得やすくなる。 As the substituted or unsubstituted vinyl group or ethynyl group in R 4 to R 9 , for example, the following can be adopted: vinyl group, 2-methylvinyl group, 2,2-dimethylvinyl group, 2-phenylvinyl. Group, 2-acetylvinyl group, ethynyl group, methylethynyl group, tert-butylethynyl group, phenylethynyl group, acetylethynyl group, trimethylsilylethynyl group. The vinyl group or ethynyl group preferably has 4 or less carbon atoms. When the number of carbon atoms is within this range, steric hindrance between fluorene rings is unlikely to occur, and desired optical characteristics derived from the fluorene ring can be easily obtained. Further, by lengthening the conjugated system of the fluorene ring, it becomes easier to obtain a stronger inverse dispersion wavelength dependence.
　Ｒ４～Ｒ９における置換基を有する硫黄原子としては、例えば、以下の硫黄含有基を採用することができる：スルホ基；メチルスルホニル基、エチルスルホニル基、プロピルスルホニル基、イソプロピルスルホニル基等のアルキルスルホニル基；フェニルスルホニル基、ｐ－トリルスルホニル基等のアリールスルホニル基；メチルスルフィニル基、エチルスルフィニル基、プロピルスルフィニル基、イソプロピルスルフィニル基等のアルキルスルフィニル基；フェニルスルフィニル基、ｐ－トリルスルフィニル基等のアリールスルフィニル基；メチルチオ基、エチルチオ基等のアルキルチオ基；フェニルチオ基、ｐ－トリルチオ基等のアリールチオ基；メトキシスルホニル基、エトキシスルホニル基等のアルコキシスルホニル基；フェノキシスルホニル基等のアリールオキシスルホニル基；アミノスルホニル基；Ｎ－メチルアミノスルホニル基、Ｎ－エチルアミノスルホニル基、Ｎ－ｔｅｒｔ－ブチルアミノスルホニル基、Ｎ，Ｎ－ジメチルアミノスルホニル基、Ｎ，Ｎ－ジエチルアミノスルホニル基等のアルキルスルホニル基；Ｎ－フェニルアミノスルホニル基、Ｎ，Ｎ－ジフェニルアミノスルホニル基等のアリールアミノスルホニル基。なお、スルホ基は、リチウム、ナトリウム、カリウム、マグネシウム、アンモニウム等と塩を形成していてもよい。メチルスルフィニル基、エチルスルフィニル基、またはフェニルスルフィニル基が好ましく、メチルスルフィニル基がより好ましい。これらは、酸性度の高いプロトンを有さず、分子量が小さく、フルオレン比率を高めることができる。 As the sulfur atom having a substituent in R 4 to R 9 , for example, the following sulfur-containing groups can be adopted: sulfo group; alkyl such as methyl sulfonyl group, ethyl sulfonyl group, propyl sulfonyl group, isopropyl sulfonyl group and the like. Sulfonyl group; arylsulfonyl group such as phenylsulfonyl group and p-tolylsulfonyl group; alkylsulfinyl group such as methylsulfinyl group, ethylsulfinyl group, propylsulfinyl group and isopropylsulfinyl group; Arylsulfinyl groups; alkylthio groups such as methylthio groups and ethylthio groups; arylthio groups such as phenylthio groups and p-tolylthio groups; alkoxysulfonyl groups such as methoxysulfonyl groups and ethoxysulfonyl groups; aryloxysulfonyl groups such as phenoxysulfonyl groups; amino Sulfonyl groups; N-methylaminosulfonyl groups, N-ethylaminosulfonyl groups, N-tert-butylaminosulfonyl groups, N, N-dimethylaminosulfonyl groups, N, N-diethylaminosulfonyl groups and other alkylsulfonyl groups; N- Arylaminosulfonyl groups such as phenylaminosulfonyl groups and N, N-diphenylaminosulfonyl groups. The sulfo group may form a salt with lithium, sodium, potassium, magnesium, ammonium or the like. A methylsulfinyl group, an ethylsulfinyl group, or a phenylsulfinyl group is preferable, and a methylsulfinyl group is more preferable. They do not have highly acidic protons, have a small molecular weight, and can increase the fluorene ratio.
　Ｒ４～Ｒ９における置換基を有するケイ素原子としては、例えば、以下のシリル基を採用することができる：トリメチルシリル基、トリエチルシリル基等のトリアルキルシリル基；トリメトキシシリル基、トリエトキシシリル基等のトリアルコキシシリル基。トリアルキルシリル基が好ましい。安定性および取扱い性に優れるからである。 As the silicon atom having a substituent in R 4 to R 9 , for example, the following silyl groups can be adopted: a trialkylsilyl group such as a trimethylsilyl group and a triethylsilyl group; a trimethoxysilyl group and a triethoxysilyl group. Such as trialkoxysilyl groups. A trialkylsilyl group is preferred. This is because it is excellent in stability and handleability.
　ポリカーボネート系樹脂等におけるオリゴフルオレン構造単位の含有量は、樹脂全体に対して、好ましくは１質量％～４０質量％であり、より好ましくは１０質量％～３５質量％であり、さらに好ましくは１５質量％～３０質量％であり、特に好ましくは１８質量％～２５質量％である。オリゴフルオレン構造単位の含有量が多すぎる場合、光弾性係数が大きくなりすぎる、信頼性が不十分となる、位相差発現性が不十分となるといった問題が生じるおそれがある。さらに、オリゴフルオレン構造単位が樹脂中に占める割合が高くなるため、分子設計の幅が狭くなり、樹脂の改質が求められた時に改良が困難となる場合がある。一方、仮に、非常に少量のオリゴフルオレン構造単位により所望の逆分散波長依存性が得られたとしても、この場合には、オリゴフルオレン構造単位の含有量のわずかなばらつきに応じて光学特性が敏感に変化するので、諸特性が一定の範囲に収まるように製造することが困難となる場合がある。 The content of the oligofluorene structural unit in the polycarbonate resin or the like is preferably 1% by mass to 40% by mass, more preferably 10% by mass to 35% by mass, and further preferably 15% by mass with respect to the entire resin. It is% to 30% by mass, and particularly preferably 18% by mass to 25% by mass. If the content of the oligofluorene structural unit is too large, problems such as an excessively large photoelastic coefficient, insufficient reliability, and insufficient phase difference expression may occur. Furthermore, since the proportion of oligofluorene structural units in the resin is high, the range of molecular design is narrowed, and it may be difficult to improve the resin when modification is required. On the other hand, even if a desired inverse dispersion wavelength dependence is obtained with a very small amount of oligofluorene structural units, in this case, the optical characteristics are sensitive to slight variations in the content of oligofluorene structural units. Therefore, it may be difficult to manufacture the product so that the characteristics fall within a certain range.
　樹脂中のオリゴフルオレン構造単位の比率を調節する方法としては、例えば、オリゴフルオレン構造単位を有するモノマーと他のモノマーを共重合する方法や、オリゴフルオレン構造単位を含有する樹脂と他の樹脂とをブレンドする方法が挙げられる。オリゴフルオレン構造単位の含有量を精密に制御でき、かつ、高い透明性が得られ、フィルムの面全体において均一な特性が得られることから、オリゴフルオレン構造単位を有するモノマーと他のモノマーを共重合する方法が好ましい。 Examples of the method for adjusting the ratio of the oligofluorene structural unit in the resin include a method of copolymerizing a monomer having an oligofluorene structural unit with another monomer, and a method of copolymerizing a resin containing an oligofluorene structural unit with another resin. There is a method of blending. Since the content of oligofluorene structural units can be precisely controlled, high transparency can be obtained, and uniform properties can be obtained over the entire surface of the film, a monomer having oligofluorene structural units can be copolymerized with another monomer. The method of doing is preferable.
＜他の構造単位＞
　ポリカーボネート系樹脂等は、代表的には、オリゴフルオレン構造単位に加えて他の構造単位を含み得る。１つの実施形態においては、他の構造単位は、好ましくはジヒドロキシ化合物またはジエステル化合物由来であり得る。目的とする逆波長分散性を発現させるためには、負の固有複屈折を有するオリゴフルオレン構造単位とともに、正の固有複屈折を有する構造単位をポリマー構造に組み込む必要があるため、共重合する他のモノマーとしては、正の複屈折を有する構造単位の原料となるジヒドロキシ化合物又はジエステル化合物がさらに好ましい。 <Other structural units>
Polycarbonate-based resins and the like may typically contain other structural units in addition to the oligofluorene structural units. In one embodiment, the other structural unit may preferably be derived from a dihydroxy compound or a diester compound. In order to achieve the desired inverse wavelength dispersibility, it is necessary to incorporate the oligofluorene structural unit having negative intrinsic birefringence and the structural unit having positive intrinsic birefringence into the polymer structure. As the monomer of, a dihydroxy compound or a diester compound which is a raw material of a structural unit having positive birefringence is more preferable.
　共重合モノマーとしては、芳香族環を含む構造単位を導入可能な化合物と、芳香族環を含む構造単位を導入しない、即ち脂肪族構造で構成される化合物が挙げられる。
　前記脂肪族構造で構成される化合物の具体例を以下に挙げる。エチレングリコール、１，３－プロパンジオール、１，２－プロパンジオール、１，４－ブタンジオール、１，３－ブタンジオール、１，２－ブタンジオール、１，５－ヘプタンジオール、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、１，１２－ドデカンジオール等の直鎖脂肪族炭化水素のジヒドロキシ化合物；ネオペンチルグリコール、ヘキシレングリコール等の分岐脂肪族炭化水素のジヒドロキシ化合物；１，２－シクロヘキサンジオール、１，４－シクロヘキサンジオール、１，３－アダマンタンジオール、水添ビスフェノールＡ、２，２，４，４－テトラメチル－１，３－シクロブタンジオール等に例示される、脂環式炭化水素の２級アルコール、及び３級アルコールであるジヒドロキシ化合物；１，２－シクロヘキサンジメタノール、１，３－シクロヘキサンジメタノール、１，４－シクロヘキサンジメタノール、トリシクロデカンジメタノール、ペンタシクロペンタデカンジメタノール、２，６－デカリンジメタノール、１，５－デカリンジメタノール、２，３－デカリンジメタノール、２，３－ノルボルナンジメタノール、２，５－ノルボルナンジメタノール、１，３－アダマンタンジメタノール、リモネン等の、テルペン化合物から誘導されるジヒドロキシ化合物等に例示される、脂環式炭化水素の１級アルコールであるジヒドロキシ化合物；ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール、ポリエチレングリコール、ポリプロピレングリコール等のオキシアルキレングリコール類；イソソルビド等の環状エーテル構造を有するジヒドロキシ化合物；スピログリコール、ジオキサングリコール等の環状アセタール構造を有するジヒドロキシ化合物；１，２－シクロヘキサンジカルボン酸、１，３－シクロヘキサンジカルボン酸、１，４－シクロヘキサンジカルボン酸等の脂環式ジカルボン酸；、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸等の脂肪族ジカルボン酸。
　前記芳香族環を含む構造単位を導入可能な化合物の具体例を以下に挙げる。２，２－ビス（４－ヒドロキシフェニル）プロパン、２，２－ビス（３－メチル－４－ヒドロキシフェニル）プロパン、２，２－ビス（４－ヒドロキシ－３，５－ジメチルフェニル）プロパン、２，２－ビス（４－ヒドロキシ－３，５－ジエチルフェニル）プロパン、２，２－ビス（４－ヒドロキシ－（３－フェニル）フェニル）プロパン、２，２－ビス（４－ヒドロキシ－（３，５－ジフェニル）フェニル）プロパン、２，２－ビス（４－ヒドロキシ－３，５－ジブロモフェニル）プロパン、ビス（４－ヒドロキシフェニル）メタン、１，１－ビス（４－ヒドロキシフェニル）エタン、２，２－ビス（４－ヒドロキシフェニル）ブタン、２，２－ビス（４－ヒドロキシフェニル）ペンタン、１，１－ビス（４－ヒドロキシフェニル）－１－フェニルエタン、ビス（４－ヒドロキシフェニル）ジフェニルメタン、１，１－ビス（４－ヒドロキシフェニル）－２－エチルヘキサン、１，１－ビス（４－ヒドロキシフェニル）デカン、ビス（４－ヒドロキシ－３－ニトロフェニル）メタン、３，３－ビス（４－ヒドロキシフェニル）ペンタン、１，３－ビス（２－（４－ヒドロキシフェニル）－２－プロピル）ベンゼン、１，３－ビス（２－（４－ヒドロキシフェニル）－２－プロピル）ベンゼン、２，２－ビス（４－ヒドロキシフェニル）ヘキサフルオロプロパン、１，１－ビス（４－ヒドロキシフェニル）シクロヘキサン、ビス（４－ヒドロキシフェニル）スルホン、２，４’－ジヒドロキシジフェニルスルホン、ビス（４－ヒドロキシフェニル）スルフィド、ビス（４－ヒドロキシ－３－メチルフェニル）スルフィド、ビス（４－ヒドロキシフェニル）ジスルフィド、４，４’－ジヒドロキシジフェニルエーテル、４，４’－ジヒドロキシ－３，３’－ジクロロジフェニルエーテル等の芳香族ビスフェノール化合物；２，２－ビス（４－（２－ヒドロキシエトキシ）フェニル）プロパン、２，２－ビス（４－（２－ヒドロキシプロポキシ）フェニル）プロパン、１，３－ビス（２－ヒドロキシエトキシ）ベンゼン、４，４’－ビス（２－ヒドロキシエトキシ）ビフェニル、ビス（４－（２－ヒドロキシエトキシ）フェニル）スルホン等の芳香族基に結合したエーテル基を有するジヒドロキシ化合物；テレフタル酸、フタル酸、イソフタル酸、４，４’－ジフェニルジカルボン酸、４，４’－ジフェニルエーテルジカルボン酸、４，４’－ベンゾフェノンジカルボン酸、４，４’－ジフェノキシエタンジカルボン酸、４，４’－ジフェニルスルホンジカルボン酸、２，６－ナフタレンジカルボン酸等の芳香族ジカルボン酸。
　尚、上記で挙げた脂肪族ジカルボン酸及び芳香族ジカルボン酸成分はジカルボン酸そのものとして前記ポリエステルカーボネートの原料とすることができるが、製造法に応じて、メチルエステル体、フェニルエステル体等のジカルボン酸エステルや、ジカルボン酸ハライド等のジカルボン酸誘導体を原料とすることもできる。 Examples of the copolymerization monomer include a compound into which a structural unit containing an aromatic ring can be introduced and a compound in which a structural unit containing an aromatic ring is not introduced, that is, a compound having an aliphatic structure.
Specific examples of the compound having the aliphatic structure are given below. Ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-heptanediol, 1,6-hexane Dihydroxy compounds of linear aliphatic hydrocarbons such as diols, 1,9-nonanediols, 1,10-decanediols and 1,12-dodecanediols; dihydroxys of branched aliphatic hydrocarbons such as neopentyl glycols and hexylene glycols. Compounds; 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantandiol, hydrogenated bisphenol A, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and the like. , Secondary alcohols of alicyclic hydrocarbons, and dihydroxy compounds which are tertiary alcohols; 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, Pentacyclopentadecanedimethanol, 2,6-decalin dimethanol, 1,5-decalin dimethanol, 2,3-decalin dimethanol, 2,3-norbornan dimethanol, 2,5-norbornan dimethanol, 1,3- Dihydroxy compounds which are primary alcohols of alicyclic hydrocarbons, such as dihydroxy compounds derived from terpene compounds such as adamantandimethanol and limonene; diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol and polypropylene. Oxyalkylene glycols such as glycols; dihydroxy compounds having a cyclic ether structure such as isosorbide; dihydroxy compounds having a cyclic acetal structure such as spiroglycol and dioxane glycol; 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, Alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelli acid, suberic acid, azelaic acid and sebacic acid.
Specific examples of the compound into which the structural unit containing the aromatic ring can be introduced are given below. 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2 , 2-bis (4-hydroxy-3,5-diethylphenyl) propane, 2,2-bis (4-hydroxy- (3-phenyl) phenyl) propane, 2,2-bis (4-hydroxy- (3,3) 5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2 , 2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane , 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 1,1-bis (4-hydroxyphenyl) decane, bis (4-hydroxy-3-nitrophenyl) methane, 3,3-bis ( 4-Hydroxyphenyl) pentane, 1,3-bis (2- (4-hydroxyphenyl) -2-propyl) benzene, 1,3-bis (2- (4-hydroxyphenyl) -2-propyl) benzene, 2 , 2-bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4'-dihydroxydiphenylsulfone, bis (4-hydroxy) Phenyl) sulfide, bis (4-hydroxy-3-methylphenyl) sulfide, bis (4-hydroxyphenyl) disulfide, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, etc. Aromatic bisphenol compound; 2,2-bis (4- (2-hydroxyethoxy) phenyl) propane, 2,2-bis (4- (2-hydroxypropoxy) phenyl) propane, 1,3-bis (2-hydroxy) Dihydroxy compound having an ether group bonded to an aromatic group such as ethoxy) benzene, 4,4'-bis (2-hydroxyethoxy) biphenyl, bis (4- (2-hydroxyethoxy) phenyl) sulfone; terephthalic acid, phthalic acid. Acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenylether dicarboxylic acid Aromatic dicarboxylic acids such as acids, 4,4'-benzophenonedicarboxylic acids, 4,4'-diphenoxyetanedicarboxylic acids, 4,4'-diphenylsulfonedicarboxylic acids, and 2,6-naphthalenedicarboxylic acids.
The aliphatic dicarboxylic acid and the aromatic dicarboxylic acid component mentioned above can be used as a raw material for the polyester carbonate as the dicarboxylic acid itself, but a dicarboxylic acid such as a methyl ester or a phenyl ester can be used depending on the production method. Dicarboxylic acid derivatives such as esters and dicarboxylic acid halides can also be used as raw materials.
　共重合モノマーとして、負の複屈折を有する構造単位を有する化合物として従来より知られている、９，９－ビス（４－（２－ヒドロキシエトキシ）フェニル）フルオレン、９，９－ビス（４－ヒドロキシフェニル）フルオレン、９，９－ビス（４－ヒドロキシ－３－メチルフェニル）フルオレン等のフルオレン環を有するジヒドロキシ化合物や、フルオレン環を有するジカルボン酸化合物もオリゴフルオレン化合物と組み合わせて用いることができる。 As a copolymerization monomer, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene and 9,9-bis (4-), which are conventionally known as compounds having a structural unit having a negative compound refraction. Dihydroxy compounds having a fluorene ring such as hydroxyphenyl) fluorene and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, and dicarboxylic acid compounds having a fluorene ring can also be used in combination with oligofluorene compounds.
　光学特性の観点からは、本発明に用いられる樹脂は、オリゴフルオレン構造単位以外の構造単位として、芳香族成分を含有しないものを用いることが好ましい。即ち、脂肪族構造で構成される化合物を共重合モノマーとして用いることが好ましい。ポリマーの主鎖に芳香族成分が含まれていると、オリゴフルオレン構造単位により発現する逆波長分散性が相殺されるため、オリゴフルオレン構造単位の含有量を増やさなければならなくなり、それにより、光弾性係数や機械物性が悪化する懸念がある。芳香族成分を含有しない前記その他の構造単位を採用することにより、当該構造単位に由来して主鎖に芳香族成分が組み込まれることを防止できる。脂肪族構造で構成される化合物の中でも、機械物性や耐熱性に優れる、脂環式構造を有する化合物がさらに好ましい。 From the viewpoint of optical properties, it is preferable that the resin used in the present invention is a structural unit other than the oligofluorene structural unit that does not contain an aromatic component. That is, it is preferable to use a compound having an aliphatic structure as the copolymerization monomer. The inclusion of aromatic components in the main chain of the polymer cancels out the inverse wavelength dispersibility developed by the oligofluorene structural units, which requires an increase in the content of the oligofluorene structural units, thereby light. There is a concern that the elastic coefficient and mechanical properties may deteriorate. By adopting the other structural unit that does not contain an aromatic component, it is possible to prevent the aromatic component from being incorporated into the main chain due to the structural unit. Among the compounds having an aliphatic structure, a compound having an alicyclic structure having excellent mechanical properties and heat resistance is more preferable.
　一方、光学特性を確保しつつ、耐熱性や機械特性等とのバランスをとるために、ポリマーの主鎖や側鎖に芳香族成分を組み込むことが有効な場合もある。諸特性のバランスをとる観点から、前記樹脂における、芳香族基を含む構造単位（但し、オリゴフルオレン構造単位を除く。）の含有量が５質量％以下であることが好ましい。 On the other hand, it may be effective to incorporate an aromatic component into the main chain or side chain of the polymer in order to balance the heat resistance and mechanical properties while ensuring the optical properties. From the viewpoint of balancing various properties, the content of the structural unit containing an aromatic group (excluding the oligofluorene structural unit) in the resin is preferably 5% by mass or less.
　本発明に用いられる樹脂は、前記脂環式構造を有する化合物によって導入可能な構造単位の中でも、共重合成分として下記式（３）で表される構造単位を含有することが好ましい。
Figure JPOXMLDOC01-appb-C000009
 The resin used in the present invention preferably contains a structural unit represented by the following formula (3) as a copolymerization component among the structural units that can be introduced by the compound having an alicyclic structure.
Figure JPOXMLDOC01-appb-C000009
　前記式（３）の構造単位を導入可能なジヒドロキシ化合物としては、スピログリコールを用いることができる。 Spiroglycol can be used as the dihydroxy compound into which the structural unit of the formula (3) can be introduced.
　本発明に用いられる樹脂において、前記式（３）で表される構造単位は５質量％以上、９０質量％以下含有されていることが好ましい。上限は７０質量％以下がさらに好ましく、５０質量％以下が特に好ましい。下限は１０質量％以上がさらに好ましく、２０質量％以上がより好ましく、２５質量％以上が特に好ましい。前記式（３）で表される構造単位の含有量が前記下限以上であれば、十分な機械物性や耐熱性、低い光弾性係数が得られる。さらに、アクリル系樹脂との相溶性が向上し、得られる樹脂組成物の透明性をさらに向上することができる。また、スピログリコールは重合反応の速度が比較的に遅いため、含有量を前記上限以下に抑えることで、重合反応を制御しやすくなる。 In the resin used in the present invention, the structural unit represented by the formula (3) is preferably contained in an amount of 5% by mass or more and 90% by mass or less. The upper limit is more preferably 70% by mass or less, and particularly preferably 50% by mass or less. The lower limit is more preferably 10% by mass or more, more preferably 20% by mass or more, and particularly preferably 25% by mass or more. When the content of the structural unit represented by the formula (3) is at least the above lower limit, sufficient mechanical characteristics, heat resistance, and a low photoelastic coefficient can be obtained. Further, the compatibility with the acrylic resin is improved, and the transparency of the obtained resin composition can be further improved. Further, since the rate of the polymerization reaction of spiroglycol is relatively slow, the polymerization reaction can be easily controlled by suppressing the content to the above upper limit or less.
　本発明に用いられる樹脂は、共重合成分としてさらに下記式（４）で表される構造単位を含有することが好ましい。
Figure JPOXMLDOC01-appb-C000010
 The resin used in the present invention preferably further contains a structural unit represented by the following formula (4) as a copolymerization component.
Figure JPOXMLDOC01-appb-C000010
　前記式（４）で表される構造単位を導入可能なジヒドロキシ化合物としては、立体異性体の関係にある、イソソルビド（ＩＳＢ）、イソマンニド、イソイデットが挙げられる。これらは１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 Examples of the dihydroxy compound into which the structural unit represented by the above formula (4) can be introduced include isosorbide (ISB), isomannide, and isoidet, which are in a stereoisomeric relationship. These may be used individually by 1 type, and may be used in combination of 2 or more type.
　本発明に用いられる樹脂において、前記式（４）で表される構造単位は５質量％以上、９０質量％以下含有されていることが好ましい。上限は７０質量％以下がさらに好ましく、５０質量％以下が特に好ましい。下限は１０質量％以上がさらに好ましく、１５質量％以上が特に好ましい。前記式（４）で表される構造単位の含有量が前記下限以上であれば、十分な機械物性や耐熱性、低い光弾性係数が得られる。また、前記式（４）で表される構造単位は吸水性が高い特性があるため、前記式（４）で表される構造単位の含有量が前記上限以下であれば、吸水による成形体の寸法変化を許容範囲に抑えることができる。 In the resin used in the present invention, the structural unit represented by the formula (4) is preferably contained in an amount of 5% by mass or more and 90% by mass or less. The upper limit is more preferably 70% by mass or less, and particularly preferably 50% by mass or less. The lower limit is more preferably 10% by mass or more, and particularly preferably 15% by mass or more. When the content of the structural unit represented by the formula (4) is at least the above lower limit, sufficient mechanical characteristics, heat resistance, and a low photoelastic coefficient can be obtained. Further, since the structural unit represented by the formula (4) has a characteristic of high water absorption, if the content of the structural unit represented by the formula (4) is equal to or less than the upper limit, the molded product by water absorption The dimensional change can be suppressed within an allowable range.
　本発明に用いられる樹脂は、さらに別の構造単位を含んでいてもよい。尚、かかる構造単位を「その他の構造単位」と称することがある。その他の構造単位を有するモノマーとしては、１，４－シクロヘキサンジメタノール、トリシクロデカンジメタノール、１，４－シクロヘキサンジカルボン酸（及びその誘導体）を採用することがより好ましく、１，４－シクロヘキサンジメタノールとトリシクロデカンジメタノールが特に好ましい。これらのモノマーに由来する構造単位を含む樹脂は、光学特性や耐熱性、機械特性等のバランスに優れている。また、ジエステル化合物の重合反応性は比較的低いため、反応効率を高める観点から、オリゴフルオレン構造単位を含有するジエステル化合物以外のジエステル化合物は用いないことが好ましい。 The resin used in the present invention may contain still another structural unit. In addition, such a structural unit may be referred to as "another structural unit". As the monomer having other structural units, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, and 1,4-cyclohexanedicarboxylic acid (and its derivatives) are more preferable, and 1,4-cyclohexanedimethanol is more preferable. Methanol and tricyclodecanedimethanol are particularly preferred. Resins containing structural units derived from these monomers have an excellent balance of optical properties, heat resistance, mechanical properties, and the like. Further, since the polymerization reactivity of the diester compound is relatively low, it is preferable not to use a diester compound other than the diester compound containing an oligofluorene structural unit from the viewpoint of increasing the reaction efficiency.
　その他の構造単位を導入するためのジヒドロキシ化合物やジエステル化合物は、得られる樹脂の要求性能に応じて、単独又は２種以上を組み合わせて用いてもよい。樹脂中のその他の構造単位の含有量は、１質量％以上、５０質量％以下が好ましく、５質量％以上、４０質量％以下がさらに好ましく、１０質量％以上、３０質量％以下が特に好ましい。その他の構造単位は特に樹脂の耐熱性の調整や、柔軟性や靱性の付与の役割を担うため、含有量が少なすぎると、樹脂の機械特性や溶融加工性が悪くなり、含有量が多すぎると、耐熱性や光学特性が悪化するおそれがある。 The dihydroxy compound or diester compound for introducing other structural units may be used alone or in combination of two or more, depending on the required performance of the obtained resin. The content of other structural units in the resin is preferably 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and particularly preferably 10% by mass or more and 30% by mass or less. Other structural units play a role in adjusting the heat resistance of the resin and imparting flexibility and toughness. Therefore, if the content is too low, the mechanical properties and melt processability of the resin deteriorate, and the content is too high. As a result, heat resistance and optical characteristics may deteriorate.
　ポリカーボネート系樹脂の分子量は、例えば還元粘度で表すことができる。還元粘度は、溶媒として塩化メチレンを用い、ポリカーボネート系樹脂の濃度を０．６ｇ／ｄＬに精密に調製し、温度２０．０℃±０．１℃でウベローデ粘度管を用いて測定される。還元粘度の下限は、通常０．３０ｄＬ／ｇ以上が好ましく、０．３５ｄＬ／ｇ以上がより好ましく、０．４０ｄＬ／ｇ以上が特に好ましい。還元粘度の上限は、通常１．００ｄＬ／ｇ以下が好ましく、０．８０ｄＬ／ｇ以下がより好ましく、０．６０ｄＬ／ｇ以下が特に好ましい。還元粘度が下限値より小さいと、得られるフィルムの機械的強度が不十分となる場合がある。一方、還元粘度が上限値より大きいと、成形性、取扱い性および生産性が不十分となる場合がある。 The molecular weight of the polycarbonate resin can be expressed, for example, by the reduced viscosity. The reduced viscosity is measured by using methylene chloride as a solvent, precisely adjusting the concentration of the polycarbonate resin to 0.6 g / dL, and using a Ubbelohde viscous tube at a temperature of 20.0 ° C. ± 0.1 ° C. The lower limit of the reduction viscosity is usually preferably 0.30 dL / g or more, more preferably 0.35 dL / g or more, and particularly preferably 0.40 dL / g or more. The upper limit of the reduction viscosity is usually preferably 1.00 dL / g or less, more preferably 0.80 dL / g or less, and particularly preferably 0.60 dL / g or less. If the reduced viscosity is less than the lower limit, the mechanical strength of the obtained film may be insufficient. On the other hand, if the reduced viscosity is larger than the upper limit, moldability, handleability and productivity may be insufficient.
　ポリカーボネート系樹脂の溶融粘度は、温度２４０℃、剪断速度９１．２ｓｅｃ－１の測定条件において７００Ｐａ・ｓ以上、５０００Ｐａ・ｓ以下であることが好ましい。上限は４０００Ｐａ・ｓ以下がさらに好ましく、３５００Ｐａ・ｓ以下がより好ましく、３０００Ｐａ・ｓ以下が特に好ましい。下限は１０００Ｐａ・ｓ以上がさらに好ましく、１５００Ｐａ・ｓ以上がより好ましく、２０００Ｐａ・ｓ以上が特に好ましい。尚、溶融粘度はキャピラリーレオメーター（東洋精機社製）を用いて測定する。 The melt viscosity of the polycarbonate resin is preferably 700 Pa · s or more and 5000 Pa · s or less under the measurement conditions of a temperature of 240 ° C. and a shear rate of 91.2 sec -1. The upper limit is more preferably 4000 Pa · s or less, more preferably 3500 Pa · s or less, and particularly preferably 3000 Pa · s or less. The lower limit is more preferably 1000 Pa · s or more, more preferably 1500 Pa · s or more, and particularly preferably 2000 Pa · s or more. The melt viscosity is measured using a capillary rheometer (manufactured by Toyo Seiki Co., Ltd.).
　本発明に用いられる樹脂のガラス転移温度（Ｔｇ）は、１１０℃以上１６０℃以下であることが好ましい。上限は１５５℃以下がさらに好ましく、１５０℃以下がより好ましく、１４５℃以下が特に好ましい。下限は１２０℃以上がさらに好ましく、１３０℃以上が特に好ましい。ガラス転移温度が上記範囲外であると耐熱性が悪くなる傾向にあり、フィルム成形後に寸法変化を起こしたり、位相差フィルムの使用条件下における品質の信頼性が悪化する可能性がある。一方、ガラス転移温度が過度に高いと、フィルム成形時にフィルム厚みの斑が生じたり、フィルムが脆くなり、延伸性が悪化したりする場合があり、また、フィルムの透明性を損なう場合がある。 The glass transition temperature (Tg) of the resin used in the present invention is preferably 110 ° C. or higher and 160 ° C. or lower. The upper limit is more preferably 155 ° C. or lower, more preferably 150 ° C. or lower, and particularly preferably 145 ° C. or lower. The lower limit is more preferably 120 ° C. or higher, and particularly preferably 130 ° C. or higher. If the glass transition temperature is out of the above range, the heat resistance tends to deteriorate, which may cause a dimensional change after film molding or deteriorate the reliability of quality under the usage conditions of the retardation film. On the other hand, if the glass transition temperature is excessively high, unevenness in the film thickness may occur during film molding, the film may become brittle, the stretchability may deteriorate, and the transparency of the film may be impaired.
　ポリカーボネート系樹脂等の構成および製造方法等の詳細は、例えば、国際公開第２０１５／１５９９２８号パンフレットに記載されている。この記載は、本明細書に参考として援用される。 Details of the composition and manufacturing method of the polycarbonate resin and the like are described in, for example, International Publication No. 2015/159928 pamphlet. This description is incorporated herein by reference.
Ａ－１－２．アクリル系樹脂
　アクリル系樹脂としては、熱可塑性樹脂としてのアクリル系樹脂が使用される。アクリル系樹脂の構造単位となる単量体としては、例えば、以下の化合物が挙げられる：メタクリル酸メチル、メタクリル酸、アクリル酸メチル、アクリル酸、ベンジル（メタ）アクリレート、ｎ－ブチル（メタ）アクリレート、ｉ－ブチル（メタ）アクリレート、ｔ－ブチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ラウリル（メタ）アクリレート、トリデシル（メタ）アクリレート、ステアリル（メタ）アクリレート、グリシジル（メタ）アクリレート、ヒドロキシプロピル（メタ）アクリレート、２－メトキシエチル（メタ）アクリレート、２－エトキシエチル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート、ノルボルニル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、ジシクロペンテニルオキシエチル（メタ）アクリレート、テトラヒドロフルフリル（メタ）アクリレート、アクリル（メタ）アクリレート、２－ヒドロキシエチル（メタ）アクリレート、コハク酸２－（メタ）アクロイルオキシエチル、マレイン酸２－（メタ）アクロイルオキシエチル、フタル酸２－（メタ）アクロイルオキシエチル、ヘキサヒドロフタル酸２－（メタ）アクリオイルオキシエチル、ペンタメチルピペリジル（メタ）アクリレート、テトラメチルピペリジル（メタ）アクリレート、ジメチルアミノエチル（メタ）アクリレート、ジエチルアミノエチル（メタ）アクリレート、シクロペンチルメタクリレート、シクロペンチルアクリレート、シクロヘキシルメタクリレート、シクロヘキシルアクリレート、シクロヘプチルメタクリレート、シクロヘプチルアクリレート、シクロオクチルメタクリレート、シクロオクチルアクリレート、シクロドデシルメタクリレート、シクロドデシルアクリレート。これらは、単独で用いてもよく、２種類以上を組み合わせて用いてもよい。２種以上の単量体を組み合わせて用いる形態は、２種以上の単量体の共重合、１種の単量体の単独重合体の２つ以上のブレンド、およびこれらの組み合わせが挙げられる。さらに、これらのアクリル系単量体と共重合可能な他の単量体（例えば、オレフィン系単量体、ビニル系単量体）を併用してもよい。 A-1-2. Acrylic resin As the acrylic resin, an acrylic resin as a thermoplastic resin is used. Examples of the monomer that becomes the structural unit of the acrylic resin include the following compounds: methyl methacrylate, methacrylic acid, methyl acrylate, acrylic acid, benzyl (meth) acrylate, n-butyl (meth) acrylate. , I-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, hydroxy Propyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, Dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acrylic (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- (meth) acrolate succinate Iloxyethyl, 2- (meth) acroyloxyethyl maleate, 2- (meth) acroyloxyethyl phthalate, 2- (meth) aclioil oxyethyl hexahydrophthalate, pentamethylpiperidyl (meth) acrylate, Tetramethylpiperidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, cyclopentyl methacrylate, cyclopentyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, cycloheptyl methacrylate, cycloheptyl acrylate, cyclooctyl methacrylate, cyclooctyl acrylate , Cyclododecyl methacrylate, Cyclododecyl acrylate. These may be used alone or in combination of two or more. Examples of the form in which two or more kinds of monomers are used in combination include copolymerization of two or more kinds of monomers, two or more blends of homopolymers of one kind of monomer, and combinations thereof. Further, other monomers copolymerizable with these acrylic monomers (for example, olefin-based monomers and vinyl-based monomers) may be used in combination.
　アクリル系樹脂は、メタクリル酸メチル由来の構造単位を含む。アクリル系樹脂におけるメタクリル酸メチル由来の構造単位の含有量は７０質量％以上、１００質量％以下が好ましい。下限は８０質量％以上がより好ましく、９０質量％以上がさらに好ましく、９５質量％以上が特に好ましい。この範囲であると、本発明のポリカーボネート系樹脂と優れた相溶性が得られる。メタクリル酸メチル以外の構造単位としては、アクリル酸メチル、フェニル（メタ）アクリレート、ベンジル（メタ）アクリレート、スチレンを用いることが好ましい。アクリル酸メチルを共重合することで熱安定性を向上させることができる。フェニル（メタ）アクリレート、ベンジル（メタ）アクリレート、スチレンを用いることで、アクリル系樹脂の屈折率を調整することができるため、組み合わせる樹脂の屈折率に合わせ込むことで、得られる樹脂組成物の透明性を向上させることができる。このようなアクリル系樹脂を用いることで、伸張性および位相差発現性に優れ、かつ、ヘイズの小さい逆分散位相差フィルムが得られ得る。 Acrylic resin contains structural units derived from methyl methacrylate. The content of the structural unit derived from methyl methacrylate in the acrylic resin is preferably 70% by mass or more and 100% by mass or less. The lower limit is more preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 95% by mass or more. Within this range, excellent compatibility with the polycarbonate resin of the present invention can be obtained. As the structural unit other than methyl methacrylate, it is preferable to use methyl acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, and styrene. Thermal stability can be improved by copolymerizing methyl acrylate. Since the refractive index of the acrylic resin can be adjusted by using phenyl (meth) acrylate, benzyl (meth) acrylate, and styrene, the transparency of the obtained resin composition can be adjusted by adjusting to the refractive index of the combined resin. The sex can be improved. By using such an acrylic resin, a reverse dispersion retardation film having excellent extensibility and phase difference expression and having a small haze can be obtained.
　アクリル系樹脂の重量平均分子量Ｍｗは、１０，０００以上、２００，０００以下である。下限は３０，０００以上が好ましく、５０，０００以上が特に好ましい。上限は１８０，０００以下が好ましく、１５０，０００以下が特に好ましい。分子量がこのような範囲であれば、本発明のポリカーボネート系樹脂との相溶性が得られることで、最終的な位相差フィルムの透明性を向上させることができ、かつ、延伸時の伸張性を十分に向上させる効果が得られる。尚、上記の重量平均分子量はＧＰＣにより測定される、ポリスチレン換算の分子量である。測定方法の詳細は後述する。また、アクリル系樹脂は実質的に分岐構造を含有しないことが相溶性の観点から好ましい。分岐構造を含有しないことは、アクリル系樹脂のＧＰＣカーブが単峰性であることなどで確認できる。 The weight average molecular weight Mw of the acrylic resin is 10,000 or more and 200,000 or less. The lower limit is preferably 30,000 or more, and particularly preferably 50,000 or more. The upper limit is preferably 180,000 or less, and particularly preferably 150,000 or less. When the molecular weight is in such a range, compatibility with the polycarbonate resin of the present invention can be obtained, so that the transparency of the final retardation film can be improved and the extensibility at the time of stretching can be improved. The effect of sufficiently improving can be obtained. The above weight average molecular weight is a polystyrene-equivalent molecular weight measured by GPC. The details of the measurement method will be described later. Further, it is preferable that the acrylic resin does not substantially contain a branched structure from the viewpoint of compatibility. The fact that it does not contain a branched structure can be confirmed by the fact that the GPC curve of the acrylic resin is monomodal.
Ａ－１－３．ポリカーボネート系樹脂等とアクリル系樹脂とのブレンド
　ポリカーボネート系樹脂等とアクリル系樹脂とはブレンドされ、樹脂組成物として位相差フィルムの製造方法に供される（製造方法はＡ－３項で後述する）。ポリカーボネート系樹脂等とアクリル系樹脂とは、好ましくは、溶融状態でブレンドされ得る。溶融状態でブレンドする方法としては、代表的には、押出機を用いた溶融混練が挙げられる。混練温度（溶融樹脂温度）は、好ましくは２００℃～２８０℃であり、より好ましくは２２０℃～２７０℃であり、さらに好ましくは２３０℃～２６０℃である。混練温度がこのような範囲であれば、熱分解を抑制しながら、両樹脂が均一にブレンドされた樹脂組成物のペレットが得られ得る。押出機中の溶融樹脂温度が２８０℃を超えると、樹脂の着色および／または熱分解が発生する場合がある。一方、押出機中の溶融樹脂温度が２００℃を下回ると、樹脂粘度が高くなり過ぎて押出機に過大な負荷が掛かったり、樹脂の溶融が不十分となる場合がある。なお、押出機の構成、スクリューの構成等としては、任意の適切な構成が採用され得る。光学フィルム用途に耐え得る樹脂の透明性を得るためには二軸押出機を用いることが好ましい。さらに、樹脂中の残存低分子成分や、押出混錬中の低分子量の熱分解成分は、製膜工程や延伸工程で冷却ロールや搬送ロールを汚染する懸念があるため、これを除去するために、真空ベントを備える押出機を用いることが好ましい。 A-1-3. Blending of Polycarbonate Resin, etc. and Acrylic Resin Polycarbonate Resin, etc. and Acrylic Resin are blended and used as a resin composition in a method for producing a retardation film (the production method will be described later in Section A-3). .. The polycarbonate-based resin or the like and the acrylic-based resin can preferably be blended in a molten state. A typical method for blending in a molten state is melt kneading using an extruder. The kneading temperature (molten resin temperature) is preferably 200 ° C. to 280 ° C., more preferably 220 ° C. to 270 ° C., and even more preferably 230 ° C. to 260 ° C. When the kneading temperature is in such a range, pellets of a resin composition in which both resins are uniformly blended can be obtained while suppressing thermal decomposition. If the temperature of the molten resin in the extruder exceeds 280 ° C., coloration and / or thermal decomposition of the resin may occur. On the other hand, if the temperature of the molten resin in the extruder is lower than 200 ° C., the viscosity of the resin may become too high and an excessive load may be applied to the extruder, or the resin may be insufficiently melted. Any appropriate configuration can be adopted as the configuration of the extruder, the configuration of the screw, and the like. It is preferable to use a twin-screw extruder in order to obtain transparency of the resin that can withstand the application of optical films. Furthermore, the residual low molecular weight components in the resin and the low molecular weight thermal decomposition components during extrusion kneading may contaminate the cooling rolls and transport rolls in the film forming process and the drawing process, so that they can be removed. , It is preferable to use an extruder equipped with a vacuum vent.
　樹脂組成物（結果として、位相差フィルム）におけるアクリル系樹脂の含有量は、上記のとおり０．５質量％以上、２．０質量％以下である。下限は０．６質量％以上がより好ましい。上限は１．５質量％以下が好ましく、１．０重量％以下がより好ましく、０．９重量％以下がさらに好ましく、０．８質量％以下が特に好ましい。このように、ポリカーボネート系樹脂にアクリル系樹脂をごく限定的な比率で配合することにより、伸張性および位相差発現性を顕著に増大させることができる。さらに、ヘイズを抑制することができる。このような効果は理論的には明らかでなく、試行錯誤により得られた予期せぬ優れた効果である。なお、アクリル系樹脂の含有量が少なすぎると、上記の効果が得られない場合がある。一方、アクリル系樹脂の含有量が多すぎると、ヘイズが高くなってしまう場合がある。また、伸張性および位相差発現性も上記範囲内の場合に比べて不十分となったり、かえって低下してしまう場合が多い。 The content of the acrylic resin in the resin composition (as a result, the retardation film) is 0.5% by mass or more and 2.0% by mass or less as described above. The lower limit is more preferably 0.6% by mass or more. The upper limit is preferably 1.5% by mass or less, more preferably 1.0% by mass or less, further preferably 0.9% by mass or less, and particularly preferably 0.8% by mass or less. As described above, by blending the acrylic resin with the polycarbonate resin in a very limited ratio, the extensibility and the phase difference expression can be remarkably increased. Furthermore, haze can be suppressed. Such an effect is not clear in theory, and is an unexpectedly excellent effect obtained by trial and error. If the content of the acrylic resin is too small, the above effect may not be obtained. On the other hand, if the content of the acrylic resin is too large, the haze may increase. In addition, the extensibility and the phase difference expression are often insufficient or even reduced as compared with the case within the above range.
　樹脂組成物は、機械特性および／または耐溶剤性等の特性を改質する目的で、芳香族ポリカーボネート、脂肪族ポリカーボネート、芳香族ポリエステル、脂肪族ポリエステル、ポリアミド、ポリスチレン、ポリオレフィン、アクリル、アモルファスポリオレフィン、ＡＢＳ、ＡＳ、ポリ乳酸、ポリブチレンスクシネート等の合成樹脂、ゴム、およびこれらの組み合わせがさらにブレンドされてもよい。 The resin composition contains aromatic polycarbonate, aliphatic polycarbonate, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic, amorphous polyolefin, for the purpose of modifying properties such as mechanical properties and / or solvent resistance. Synthetic resins such as ABS, AS, polylactic acid, polybutylene succinate, rubber, and combinations thereof may be further blended.
　樹脂組成物は、添加剤をさらに含んでいてもよい。添加剤の具体例としては、熱安定剤、酸化防止剤、触媒失活剤、紫外線吸収剤、光安定剤、離型剤、染顔料、衝撃改良剤、帯電防止剤、滑剤、潤滑剤、可塑剤、相溶化剤、核剤、難燃剤、無機充填剤、発泡剤が挙げられる。樹脂組成物に含まれる添加剤の種類、数、組み合わせ、含有量等は、目的に応じて適切に設定され得る。 The resin composition may further contain additives. Specific examples of additives include heat stabilizers, antioxidants, catalyst deactivators, ultraviolet absorbers, light stabilizers, mold release agents, dye pigments, impact improvers, antistatic agents, lubricants, lubricants, and plasticizers. Examples include agents, compatibilizers, nucleating agents, flame retardants, inorganic fillers and effervescent agents. The type, number, combination, content, etc. of the additives contained in the resin composition can be appropriately set according to the purpose.
Ａ－２．位相差フィルムの特性
　位相差フィルムの面内位相差Ｒｅ（５５０）は、上記のとおり１００ｎｍ～２００ｎｍであり、好ましくは１１０ｎｍ～１８０ｎｍであり、より好ましくは１２０ｎｍ～１６０ｎｍであり、さらに好ましくは１３０ｎｍ～１５０ｎｍである。すなわち、位相差フィルムは、いわゆるλ／４板として機能し得る。 A-2. Characteristics of the retardation film The in-plane retardation Re (550) of the retardation film is 100 nm to 200 nm, preferably 110 nm to 180 nm, more preferably 120 nm to 160 nm, and further preferably 130 nm to 130 nm as described above. It is 150 nm. That is, the retardation film can function as a so-called λ / 4 plate.
　位相差フィルムは、代表的には、Ｒｅ（４５０）＜Ｒｅ（５５０）＜Ｒｅ（６５０）の関係を満たす。すなわち、位相差フィルムは、位相差値が測定光の波長に応じて大きくなる逆分散の波長依存性を示す。位相差フィルムのＲｅ（４５０）／Ｒｅ（５５０）は、上記のとおり０．５を超えて１．０未満であり、好ましくは０．７～０．９５であり、より好ましくは０．７５～０．９２であり、さらに好ましくは０．８～０．９である。Ｒｅ（６５０）／Ｒｅ（５５０）は、好ましくは１．０以上１．１５未満であり、より好ましくは１．０３～１．１である。 The retardation film typically satisfies the relationship of Re (450) <Re (550) <Re (650). That is, the retardation film exhibits a wavelength dependence of inverse dispersion in which the retardation value increases according to the wavelength of the measurement light. The Re (450) / Re (550) of the retardation film is more than 0.5 and less than 1.0 as described above, preferably 0.7 to 0.95, and more preferably 0.75 to 0.75. It is 0.92, more preferably 0.8 to 0.9. Re (650) / Re (550) is preferably 1.0 or more and less than 1.15, and more preferably 1.03 to 1.1.
　位相差フィルムは、上記のように面内位相差を有するので、ｎｘ＞ｎｙの関係を有する。位相差フィルムは、ｎｘ＞ｎｙの関係を有する限り、任意の適切な屈折率楕円体を示す。位相差フィルムの屈折率楕円体は、代表的にはｎｘ＞ｎｙ≧ｎｚの関係を示す。なお、ここで「ｎｙ＝ｎｚ」はｎｙとｎｚが完全に等しい場合だけではなく、実質的に等しい場合を包含する。したがって、本発明の効果を損なわない範囲で、ｎｙ＜ｎｚとなる場合があり得る。位相差フィルムのＮｚ係数は、好ましくは０．９～２．０であり、より好ましくは０．９～１．５であり、さらに好ましくは０．９～１．２である。このような関係を満たすことにより、位相差フィルムを含む円偏光板を画像表示装置に用いた場合に、非常に優れた反射色相を達成し得る。 Since the retardation film has an in-plane retardation as described above, it has a relationship of nx> ny. The retardation film exhibits any suitable index of refraction ellipsoid as long as it has an nx> ny relationship. The refractive index ellipsoid of the retardation film typically shows a relationship of nx> ny ≧ nz. Here, "ny = nz" includes not only the case where ny and nz are completely equal, but also the case where they are substantially equal. Therefore, ny <nz may be satisfied as long as the effect of the present invention is not impaired. The Nz coefficient of the retardation film is preferably 0.9 to 2.0, more preferably 0.9 to 1.5, and even more preferably 0.9 to 1.2. By satisfying such a relationship, a very excellent reflected hue can be achieved when a circularly polarizing plate including a retardation film is used in an image display device.
　位相差フィルムの厚みは、λ／４板として最も適切に機能し得るように設定され得る。言い換えれば、厚みは、所望の面内位相差が得られるように設定され得る。具体的には、厚みは、好ましくは１５μｍ～６０μｍであり、さらに好ましくは２０μｍ～５５μｍであり、最も好ましくは２０μｍ～４５μｍである。本発明の実施形態によれば、位相差発現性に優れた位相差フィルムが得られるので、通常のλ／４板に比べて位相差フィルムの厚みを顕著に薄くすることができる。 The thickness of the retardation film can be set so that it can function most appropriately as a λ / 4 plate. In other words, the thickness can be set to obtain the desired in-plane phase difference. Specifically, the thickness is preferably 15 μm to 60 μm, more preferably 20 μm to 55 μm, and most preferably 20 μm to 45 μm. According to the embodiment of the present invention, since a retardation film having excellent retardation expression can be obtained, the thickness of the retardation film can be remarkably reduced as compared with a normal λ / 4 plate.
　位相差フィルムのヘイズ値は、好ましくは１．５％以下であり、より好ましくは１．０％以下であり、さらに好ましくは０．５％以下である。本発明の実施形態によれば、位相差発現性およびヘイズ値の両方に優れた逆分散位相差フィルムを実現することができる。ヘイズ値は小さければ小さいほど好ましい。ヘイズ値の下限は、例えば０．１％であり得る。 The haze value of the retardation film is preferably 1.5% or less, more preferably 1.0% or less, and further preferably 0.5% or less. According to the embodiment of the present invention, it is possible to realize a reverse dispersion retardation film excellent in both retardation expression and haze value. The smaller the haze value, the more preferable. The lower limit of the haze value can be, for example, 0.1%.
　位相差フィルムの破断伸びは、好ましくは２００％以上であり、より好ましくは２１０％以上であり、さらに好ましくは２２０％以上であり、特に好ましくは２４５％以上である。破断伸びの上限は、例えば５００％であり得る。本発明の実施形態による位相差フィルムは位相差発現性に優れることに加えて、このように伸張性にも優れるので、これらの相乗効果により非常に薄い厚みで所望の面内位相差を実現し得る。なお、本明細書において「破断伸び」とは、所定の延伸温度（例えば、Ｔｇ－２℃）での固定端一軸延伸においてフィルムが破断した時の伸び率を意味する。 The elongation at break of the retardation film is preferably 200% or more, more preferably 210% or more, further preferably 220% or more, and particularly preferably 245% or more. The upper limit of elongation at break can be, for example, 500%. Since the retardation film according to the embodiment of the present invention is excellent in extensibility in addition to being excellent in phase difference expression, a desired in-plane retardation is realized with a very thin thickness by these synergistic effects. obtain. In addition, in this specification, "breaking elongation" means the elongation rate at the time of breaking of a film in fixed-end uniaxial stretching at a predetermined stretching temperature (for example, Tg-2 ° C.).
　位相差フィルムの限界複屈折Δｎは、好ましくは０．００３９以上であり、より好ましくは０．００４０以上であり、さらに好ましくは０．００４１以上であり、特に好ましくは０．００４４以上である。限界複屈折Δｎの上限は、例えば０．００７０であり得る。このように、本発明の実施形態による位相差フィルムは非常に高い複屈折性を有するので、非常に薄い厚みで所望の面内位相差を実現し得る。なお、本明細書において「限界複屈折」とは、所定の延伸温度で延伸倍率を大きくしていった場合に、破断しない最高延伸倍率における複屈折を意味する。複屈折は、破断しない最高延伸倍率におけるフィルムの面内位相差Ｒｅをフィルム厚みｄで除することにより求められ得る。 The limit birefringence Δn of the retardation film is preferably 0.0039 or more, more preferably 0.0040 or more, still more preferably 0.0041 or more, and particularly preferably 0.0044 or more. The upper limit of the limit birefringence Δn can be, for example, 0.0070. As described above, since the retardation film according to the embodiment of the present invention has very high birefringence, a desired in-plane retardation can be realized with a very thin thickness. In addition, in this specification, "limit birefringence" means birefringence at the maximum stretching ratio which does not break when the stretching ratio is increased at a predetermined stretching temperature. Birefringence can be obtained by dividing the in-plane retardation Re of the film at the maximum unbreakable draw ratio by the film thickness d.
　位相差フィルムは、その光弾性係数の絶対値が好ましくは２０×１０－１２（ｍ２／Ｎ）以下であり、より好ましくは１．０×１０－１２（ｍ２／Ｎ）～１５×１０－１２（ｍ２／Ｎ）であり、さらに好ましくは２．０×１０－１２（ｍ２／Ｎ）～１２×１０－１２（ｍ２／Ｎ）である。光弾性係数の絶対値がこのような範囲であれば、位相差フィルムを画像表示装置に適用した場合に表示ムラを抑制することができる。 The absolute value of the photoelastic coefficient of the retardation film is preferably 20 × 10-12 (m 2 / N) or less, more preferably 1.0 × 10-12 (m 2 / N) to 15 × 10. It is -12 (m 2 / N), more preferably 2.0 × 10 -12 (m 2 / N) to 12 × 10 -12 (m 2 / N). When the absolute value of the photoelastic coefficient is in such a range, display unevenness can be suppressed when the retardation film is applied to an image display device.
Ａ－３．位相差フィルムの製造方法
　上記Ａ－１項およびＡ－２項に記載の位相差フィルムは、Ａ－１項に記載の樹脂組成物からフィルムを形成し、さらにそのフィルムを延伸することにより得られる。樹脂組成物からフィルムを形成する方法としては、任意の適切な成形加工法が採用され得る。具体例としては、圧縮成形法、トランスファー成形法、射出成形法、押出成形法、ブロー成形法、粉末成形法、ＦＲＰ成形法、キャスト塗工法（例えば、流延法）、カレンダー成形法、熱プレス法等が挙げられる。中でも得られるフィルムの平滑性を高め、良好な光学的均一性を得ることができる押出成形法、またはキャスト塗工法が好ましい。キャスト塗工法では残存溶媒による問題が生じるおそれがあるため、特に好ましくは押出成形法、中でもＴダイを用いた溶融押出成形法がフィルムの生産性や、後の延伸処理のし易さの観点から好ましい。成形条件は、使用される樹脂の組成や種類、位相差フィルムに所望される特性等に応じて適宜設定され得る。このようにして、ポリカーボネート系樹脂等とアクリル系樹脂とを含む樹脂フィルムが得られ得る。 A-3. Method for producing a retardation film The retardation film according to the above items A-1 and A-2 can be obtained by forming a film from the resin composition according to the item A-1 and further stretching the film. .. As a method for forming a film from the resin composition, any suitable molding processing method can be adopted. Specific examples include a compression molding method, a transfer molding method, an injection molding method, an extrusion molding method, a blow molding method, a powder molding method, an FRP molding method, a cast coating method (for example, a casting method), a calendar molding method, and a hot press. Law etc. can be mentioned. Of these, an extrusion molding method or a cast coating method, which can improve the smoothness of the obtained film and obtain good optical uniformity, is preferable. Since the cast coating method may cause problems due to the residual solvent, the extrusion molding method, particularly the melt extrusion molding method using a T-die, is particularly preferable from the viewpoint of film productivity and ease of subsequent stretching treatment. preferable. The molding conditions can be appropriately set according to the composition and type of the resin used, the characteristics desired for the retardation film, and the like. In this way, a resin film containing a polycarbonate-based resin or the like and an acrylic-based resin can be obtained.
　樹脂フィルム（未延伸フィルム）の厚みは、得られる位相差フィルムの所望の厚み、所望の光学特性、後述の延伸条件などに応じて、任意の適切な値に設定され得る。好ましくは５０μｍ～３００μｍである。 The thickness of the resin film (unstretched film) can be set to an arbitrary appropriate value according to the desired thickness of the obtained retardation film, desired optical characteristics, stretching conditions described later, and the like. It is preferably 50 μm to 300 μm.
　上記延伸は、任意の適切な延伸方法、延伸条件（例えば、延伸温度、延伸倍率、延伸方向）が採用され得る。具体的には、自由端延伸、固定端延伸、自由端収縮、固定端収縮などの様々な延伸方法を、単独で用いることも、同時もしくは逐次で用いることもできる。延伸方向に関しても、長さ方向、幅方向、厚さ方向、斜め方向等、様々な方向や次元に行なうことができる。 For the above stretching, any appropriate stretching method and stretching conditions (for example, stretching temperature, stretching ratio, stretching direction) can be adopted. Specifically, various stretching methods such as free-end stretching, fixed-end stretching, free-end contraction, and fixed-end contraction can be used alone or simultaneously or sequentially. As for the stretching direction, it can be performed in various directions and dimensions such as a length direction, a width direction, a thickness direction, and an oblique direction.
　上記延伸方法、延伸条件を適宜選択することにより、上記所望の光学特性（例えば、屈折率特性、面内位相差、Ｎｚ係数）を有する位相差フィルムを得ることができる。 By appropriately selecting the stretching method and stretching conditions, a retardation film having the desired optical characteristics (for example, refractive index characteristics, in-plane retardation, Nz coefficient) can be obtained.
　１つの実施形態においては、位相差フィルムは、樹脂フィルムを一軸延伸もしくは固定端一軸延伸することにより作製される。一軸延伸の具体例としては、樹脂フィルムを長尺方向に走行させながら、走行方向（長尺方向）に延伸する方法が挙げられる。固定端一軸延伸の具体例としては、樹脂フィルムを長尺方向に走行させながら、幅方向（横方向）に延伸する方法が挙げられる。延伸倍率は、好ましくは１．１倍～３．５倍である。 In one embodiment, the retardation film is produced by uniaxially stretching or fixed end uniaxially stretching the resin film. Specific examples of the uniaxial stretching include a method of stretching the resin film in the traveling direction (long direction) while traveling in the elongated direction. Specific examples of the fixed-end uniaxial stretching include a method of stretching the resin film in the width direction (lateral direction) while running the resin film in the long direction. The draw ratio is preferably 1.1 times to 3.5 times.
　別の実施形態においては、位相差フィルムは、長尺状の樹脂フィルムを長尺方向に対して所定の角度の方向に連続的に斜め延伸することにより作製され得る。斜め延伸を採用することにより、フィルムの長尺方向に対して所定の角度の配向角（所定の角度の方向に遅相軸）を有する長尺状の延伸フィルムが得られ、例えば、偏光子との積層に際してロールトゥロールが可能となり、製造工程を簡略化することができる。なお、上記所定の角度は、円偏光板（後述）において偏光子の吸収軸と位相差フィルムの遅相軸とがなす角度であり得る。当該角度は、後述のとおり、好ましくは４０°～５０°であり、より好ましくは４２°～４８°であり、さらに好ましくは４４°～４６°であり、特に好ましくは約４５°であり；あるいは、好ましくは１３０°～１４０°であり、より好ましくは１３２°～１３８°であり、さらに好ましくは１３４°～１３６°であり、特に好ましくは約１３５°である。 In another embodiment, the retardation film can be produced by continuously obliquely stretching a long resin film in a direction of a predetermined angle with respect to the long direction. By adopting oblique stretching, a long stretched film having an orientation angle (delayed axis in the direction of a predetermined angle) at a predetermined angle with respect to the long direction of the film can be obtained, for example, with a polarizer. Roll-to-roll is possible at the time of laminating, and the manufacturing process can be simplified. The predetermined angle may be an angle formed by the absorption axis of the polarizer and the slow axis of the retardation film in the circularly polarizing plate (described later). The angle is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, still more preferably 44 ° to 46 °, and particularly preferably about 45 °; as described below; It is preferably 130 ° to 140 °, more preferably 132 ° to 138 °, still more preferably 134 ° to 136 °, and particularly preferably about 135 °.
　斜め延伸に用いる延伸機としては、例えば、横および／または縦方向に、左右異なる速度の送り力もしくは引張り力または引き取り力を付加し得るテンター式延伸機が挙げられる。テンター式延伸機には、横一軸延伸機、同時二軸延伸機等があるが、長尺状の樹脂フィルムを連続的に斜め延伸し得る限り、任意の適切な延伸機が用いられ得る。 Examples of the stretching machine used for diagonal stretching include a tenter type stretching machine capable of applying a feeding force, a pulling force, or a pulling force at different speeds in the horizontal and / or vertical directions. The tenter type stretching machine includes a horizontal uniaxial stretching machine, a simultaneous biaxial stretching machine, and the like, but any suitable stretching machine can be used as long as the long resin film can be continuously and diagonally stretched.
　上記延伸機において左右の速度をそれぞれ適切に制御することにより、上記所望の面内位相差を有し、かつ、上記所望の方向に遅相軸を有する位相差フィルム（実質的には、長尺状の位相差フィルム）が得られ得る。 By appropriately controlling the left and right velocities in the stretching machine, a retardation film having the desired in-plane retardation and having a slow phase axis in the desired direction (substantially long). (Phase difference film) can be obtained.
　斜め延伸の方法としては、例えば、特開昭５０－８３４８２号公報、特開平２－１１３９２０号公報、特開平３－１８２７０１号公報、特開２０００－９９１２号公報、特開２００２－８６５５４号公報、特開２００２－２２９４４号公報等に記載の方法が挙げられる。 Examples of the method of diagonal stretching include JP-A-50-83482, JP-A-2-113920, JP-A-3-182701, JP-A-2000-9912, and JP-A-2002-86554. Examples thereof include the methods described in JP-A-2002-22944.
　上記フィルムの延伸温度は、１つの実施形態においては、ポリカーボネート系樹脂等のガラス転移温度（Ｔｇ）以下の温度である。通常、ポリカーボネート系樹脂等のフィルムを延伸する場合、Ｔｇ以下の温度ではフィルムがガラス状態であるので、延伸は実質的には不可能である。本発明の実施形態によれば、アクリル系樹脂（代表的には、ポリメチルメタクリレート）を少量配合することにより、ポリカーボネート系樹脂等のＴｇを実質的に変化させることなく、Ｔｇ以下での延伸が可能となる。さらに、理論的には明らかではないが、Ｔｇ以下で延伸を行うことにより、伸張性および位相差発現性に優れ、かつ、ヘイズの小さい逆分散位相差フィルムを実現することができる。具体的には、延伸温度は、好ましくはＴｇ～Ｔｇ－１０℃であり、より好ましくはＴｇ～Ｔｇ－８℃であり、さらに好ましくはＴｇ～Ｔｇ－５℃である。なお、上記フィルムは、例えばＴｇ＋５℃程度、また例えばＴｇ＋２℃程度までであれば、Ｔｇよりも高い温度であっても適切に延伸され得る。 In one embodiment, the stretching temperature of the film is a temperature equal to or lower than the glass transition temperature (Tg) of a polycarbonate resin or the like. Usually, when a film such as a polycarbonate resin is stretched, the film is in a glass state at a temperature of Tg or less, so that stretching is practically impossible. According to the embodiment of the present invention, by blending a small amount of an acrylic resin (typically, polymethylmethacrylate), stretching at Tg or less can be performed without substantially changing the Tg of the polycarbonate resin or the like. It will be possible. Further, although it is not theoretically clear, by stretching at Tg or less, it is possible to realize a reverse dispersion retardation film having excellent extensibility and phase difference expression and having a small haze. Specifically, the stretching temperature is preferably Tg to Tg-10 ° C, more preferably Tg to Tg-8 ° C, and even more preferably Tg to Tg-5 ° C. The film can be appropriately stretched even at a temperature higher than Tg as long as it is, for example, about Tg + 5 ° C., and for example, about Tg + 2 ° C.
［効果を奏する理由］
　本発明の樹脂組成物からなるフィルムが優れた特性を発現する理由については、下記の通り推測する。後述する実施例で示すように、適切な組成のアクリル系樹脂を、限定的な比率で配合した樹脂組成物については、ポリカーボネート系樹脂単体とほぼ同等の透明性を保持しつつ、延伸時の限界破断倍率が明らかに向上している。ポリカーボネート系樹脂とアクリル系樹脂とは完全相溶しているものと推測され、ポリカーボネート系樹脂に溶け込んだアクリル系樹脂のポリマー鎖によって、ポリカーボネート系樹脂のポリマー鎖の絡み合いが増大し、フィルムの破断強度が向上していることが考えられる。単体のアクリル系樹脂の固有複屈折はほぼゼロであるため、本来はアクリル系樹脂を配合することで、その樹脂組成物の固有複屈折は低下し、延伸により発現する配向複屈折は低下することが予想される。しかし、本発明では、アクリル系樹脂の配合量をごく少量であるため、アクリル系樹脂による固有複屈折低下の影響をほぼゼロに抑えつつ、樹脂組成物の延伸強度を向上させることに成功し、配向複屈折が向上したと考えられる。 [Reason for effectiveness]
The reason why the film made of the resin composition of the present invention exhibits excellent properties is presumed as follows. As shown in Examples described later, for a resin composition in which an acrylic resin having an appropriate composition is blended in a limited ratio, the limit at the time of stretching is maintained while maintaining almost the same transparency as the polycarbonate resin alone. The breaking ratio is clearly improved. It is presumed that the polycarbonate resin and the acrylic resin are completely compatible with each other, and the polymer chains of the acrylic resin dissolved in the polycarbonate resin increase the entanglement of the polymer chains of the polycarbonate resin, resulting in the breaking strength of the film. Is considered to be improving. Since the intrinsic birefringence of a single acrylic resin is almost zero, the intrinsic birefringence of the resin composition is reduced by blending the acrylic resin, and the orientation birefringence developed by stretching is reduced. Is expected. However, in the present invention, since the blending amount of the acrylic resin is very small, it has succeeded in improving the stretching strength of the resin composition while suppressing the influence of the decrease in the intrinsic birefringence due to the acrylic resin to almost zero. It is considered that the orientation birefringence was improved.
Ｂ．円偏光板
　上記Ａ項に記載の本発明の実施形態による位相差フィルムは、円偏光板に好適に用いられ得る。したがって、本発明の実施形態は、円偏光板も包含する。図１は、本発明の１つの実施形態による円偏光板の概略断面図である。図示例の円偏光板１００は、偏光板１０と位相差フィルム２０とを有する。位相差フィルム２０は、上記Ａ項に記載の本発明の実施形態による位相差フィルムである。偏光板１０は、偏光子１１と、偏光子１１の一方の側に配置された第１の保護層１２と、偏光子１１のもう一方の側に配置された第２の保護層１３とを含む。目的に応じて、第１の保護層１２および第２の保護層１３の一方は省略されてもよい。例えば、本発明の実施形態による位相差フィルム２０は偏光子１１の保護層としても機能し得るので、第２の保護層１３は省略されてもよい。位相差フィルム２０の遅相軸と偏光子１１の吸収軸とのなす角度は、好ましくは４０°～５０°であり、より好ましくは４２°～４８°であり、さらに好ましくは４４°～４６°であり、特に好ましくは約４５°であり；あるいは、好ましくは１３０°～１４０°であり、より好ましくは１３２°～１３８°であり、さらに好ましくは１３４°～１３６°であり、特に好ましくは約１３５°である。 B. Circularly polarized light The retardation film according to the embodiment of the present invention according to the above item A can be suitably used for a circularly polarizing plate. Therefore, embodiments of the present invention also include circularly polarizing plates. FIG. 1 is a schematic cross-sectional view of a circularly polarizing plate according to one embodiment of the present invention. The circularly polarizing plate 100 of the illustrated example has a polarizing plate 10 and a retardation film 20. The retardation film 20 is a retardation film according to the embodiment of the present invention according to the above item A. The polarizing plate 10 includes a polarizer 11, a first protective layer 12 arranged on one side of the polarizer 11, and a second protective layer 13 arranged on the other side of the polarizer 11. .. Depending on the purpose, one of the first protective layer 12 and the second protective layer 13 may be omitted. For example, since the retardation film 20 according to the embodiment of the present invention can also function as a protective layer for the polarizer 11, the second protective layer 13 may be omitted. The angle formed by the slow axis of the retardation film 20 and the absorption axis of the polarizer 11 is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, and even more preferably 44 ° to 46 °. It is particularly preferably about 45 °; or preferably 130 ° to 140 °, more preferably 132 ° to 138 °, still more preferably 134 ° to 136 °, and particularly preferably about. It is 135 °.
　図２に示すように、別の実施形態による円偏光板１０１においては、別の位相差層５０ならびに／あるいは導電層または導電層付等方性基材６０が設けられてもよい。別の位相差層５０ならびに導電層または導電層付等方性基材６０は、代表的には、位相差フィルム２０の外側（偏光板１０と反対側）に設けられる。別の位相差層は、代表的には、屈折率特性がｎｚ＞ｎｘ＝ｎｙの関係を示す。このような別の位相差層を設けることにより、斜め方向の反射を良好に防止することができ、反射防止機能の広視野角化が可能となる。別の位相差層５０ならびに導電層または導電層付等方性基材６０は、代表的には、位相差フィルム２０側からこの順に設けられる。別の位相差層５０ならびに導電層または導電層付等方性基材６０は、代表的には、必要に応じて設けられる任意の層であり、いずれか一方または両方が省略されてもよい。なお、導電層または導電層付等方性基材が設けられる場合、円偏光板は、画像表示セル（例えば、有機ＥＬセル）と偏光板との間にタッチセンサが組み込まれた、いわゆるインナータッチパネル型入力表示装置に適用され得る。 As shown in FIG. 2, in the circularly polarizing plate 101 according to another embodiment, another retardation layer 50 and / or a conductive layer or an isotropic base material 60 with a conductive layer may be provided. Another retardation layer 50 and the conductive layer or the isotropic base material 60 with the conductive layer are typically provided on the outside of the retardation film 20 (opposite to the polarizing plate 10). Another retardation layer typically exhibits a relationship in which the refractive index characteristic is nz> nz = ny. By providing such another retardation layer, it is possible to satisfactorily prevent reflection in the oblique direction, and it is possible to widen the viewing angle of the antireflection function. Another retardation layer 50 and the conductive layer or the isotropic base material 60 with the conductive layer are typically provided in this order from the retardation film 20 side. The other retardation layer 50 and the conductive layer or the isotropic base material 60 with the conductive layer are typically arbitrary layers provided as needed, and one or both of them may be omitted. When an isotropic base material with a conductive layer or a conductive layer is provided, the circularly polarizing plate is a so-called inner touch panel type input in which a touch sensor is incorporated between an image display cell (for example, an organic EL cell) and the polarizing plate. Can be applied to display devices.
　円偏光板は、さらなる位相差層を有していてもよい。さらなる位相差層は、別の位相差層５０と組み合わせて設けられてもよく、単独で（すなわち、別の位相差層５０を設けることなく）設けられてもよい。さらなる位相差層の光学的特性（例えば、屈折率特性、面内位相差、Ｎｚ係数、光弾性係数）、厚み、配置位置等は、目的に応じて適切に設定され得る。 The circularly polarizing plate may have an additional retardation layer. The additional retardation layer may be provided in combination with another retardation layer 50, or may be provided alone (that is, without providing another retardation layer 50). The optical characteristics (for example, refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, and the like of the further retardation layer can be appropriately set according to the purpose.
　円偏光板は、枚葉状であってもよく長尺状であってもよい。本明細書において「長尺状」とは、幅に対して長さが十分に長い細長形状を意味し、例えば、幅に対して長さが１０倍以上、好ましくは２０倍以上の細長形状を含む。長尺状の円偏光板は、ロール状に巻回可能である。円偏光板が長尺状である場合、偏光板および位相差フィルムも長尺状である。この場合、偏光子は、好ましくは長尺方向に吸収軸を有する。位相差フィルムは、好ましくは上記のとおり、長尺方向に対して４０°～５０°または１３０°～１４０°の角度をなす方向に遅相軸を有する斜め延伸フィルムである。偏光子および位相差フィルムがこのような構成であれば、円偏光板をロールトゥロールにより作製することができる。 The circularly polarizing plate may be single-wafered or elongated. As used herein, the term "long" means an elongated shape having a length sufficiently long with respect to the width, and for example, an elongated shape having a length of 10 times or more, preferably 20 times or more with respect to the width. Including. The elongated circularly polarizing plate can be wound in a roll shape. When the circularly polarizing plate is elongated, the polarizing plate and the retardation film are also elongated. In this case, the polarizer preferably has an absorption axis in the longitudinal direction. As described above, the retardation film is preferably an obliquely stretched film having a slow phase axis in a direction forming an angle of 40 ° to 50 ° or 130 ° to 140 ° with respect to the elongated direction. If the polarizer and the retardation film have such a configuration, a circularly polarizing plate can be produced by roll-to-roll.
　実用的には、位相差フィルムの偏光板と反対側には粘着剤層（図示せず）が設けられ、円偏光板は画像表示セルに貼り付け可能とされている。さらに、粘着剤層の表面には、円偏光板が使用に供されるまで、剥離フィルムが仮着されていることが好ましい。剥離フィルムを仮着することにより、粘着剤層を保護するとともに、円偏光板のロール形成が可能となる。 Practically, an adhesive layer (not shown) is provided on the opposite side of the retardation film to the polarizing plate, and the circular polarizing plate can be attached to the image display cell. Further, it is preferable that a release film is temporarily attached to the surface of the pressure-sensitive adhesive layer until the circularly polarizing plate is used. By temporarily attaching the release film, the pressure-sensitive adhesive layer can be protected and a roll of a circularly polarizing plate can be formed.
　以下、円偏光板の構成要素について説明する。 Hereinafter, the components of the circularly polarizing plate will be described.
Ｂ－１．偏光子
　偏光子１１としては、任意の適切な偏光子が採用され得る。例えば、偏光子を形成する樹脂フィルムは、単層の樹脂フィルムであってもよく、二層以上の積層体であってもよい。 B-1. Polarizer As the polarizer 11, any suitable polarizer can be adopted. For example, the resin film forming the polarizer may be a single-layer resin film or a laminated body having two or more layers.
　単層の樹脂フィルムから構成される偏光子の具体例としては、ポリビニルアルコール（ＰＶＡ）系フィルム、部分ホルマール化ＰＶＡ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による染色処理および延伸処理が施されたもの、ＰＶＡの脱水処理物やポリ塩化ビニルの脱塩酸処理物等ポリエン系配向フィルム等が挙げられる。好ましくは、光学特性に優れることから、ＰＶＡ系フィルムをヨウ素で染色し一軸延伸して得られた偏光子が用いられる。 Specific examples of the polarizer composed of a single-layer resin film include a hydrophilic polymer film such as a polyvinyl alcohol (PVA) -based film, a partially formalized PVA-based film, and an ethylene / vinyl acetate copolymer system partially saponified film. Examples thereof include those which have been dyed and stretched with a bicolor substance such as iodine or a bicolor dye, and polyene-based oriented films such as a dehydrated product of PVA and a dehydrogenated product of polyvinyl chloride. Preferably, since the PVA-based film is excellent in optical properties, a polarizer obtained by dyeing a PVA-based film with iodine and uniaxially stretching the film is used.
　上記ヨウ素による染色は、例えば、ＰＶＡ系フィルムをヨウ素水溶液に浸漬することにより行われる。上記一軸延伸の延伸倍率は、好ましくは３～７倍である。延伸は、染色処理後に行ってもよいし、染色しながら行ってもよい。また、延伸してから染色してもよい。必要に応じて、ＰＶＡ系フィルムに、膨潤処理、架橋処理、洗浄処理、乾燥処理等が施される。例えば、染色の前にＰＶＡ系フィルムを水に浸漬して水洗することで、ＰＶＡ系フィルム表面の汚れやブロッキング防止剤を洗浄することができるだけでなく、ＰＶＡ系フィルムを膨潤させて染色ムラなどを防止することができる。 The above-mentioned dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. Alternatively, it may be stretched and then dyed. If necessary, the PVA-based film is subjected to a swelling treatment, a cross-linking treatment, a washing treatment, a drying treatment and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, it is possible not only to clean the dirt and blocking inhibitor on the surface of the PVA-based film, but also to swell the PVA-based film to prevent uneven dyeing. Can be prevented.
　積層体を用いて得られる偏光子の具体例としては、樹脂基材と当該樹脂基材に積層されたＰＶＡ系樹脂層（ＰＶＡ系樹脂フィルム）との積層体、あるいは、樹脂基材と当該樹脂基材に塗布形成されたＰＶＡ系樹脂層との積層体を用いて得られる偏光子が挙げられる。樹脂基材と当該樹脂基材に塗布形成されたＰＶＡ系樹脂層との積層体を用いて得られる偏光子は、例えば、ＰＶＡ系樹脂溶液を樹脂基材に塗布し、乾燥させて樹脂基材上にＰＶＡ系樹脂層を形成して、樹脂基材とＰＶＡ系樹脂層との積層体を得ること；当該積層体を延伸および染色してＰＶＡ系樹脂層を偏光子とすること；により作製され得る。本実施形態においては、延伸は、代表的には積層体をホウ酸水溶液中に浸漬させて延伸することを含む。さらに、延伸は、必要に応じて、ホウ酸水溶液中での延伸の前に積層体を高温（例えば、９５℃以上）で空中延伸することをさらに含み得る。得られた樹脂基材／偏光子の積層体はそのまま用いてもよく（すなわち、樹脂基材を偏光子の保護層としてもよく）、樹脂基材／偏光子の積層体から樹脂基材を剥離し、当該剥離面に目的に応じた任意の適切な保護層を積層して用いてもよい。このような偏光子の製造方法の詳細は、例えば特開２０１２－７３５８０号公報、特許第６４７０４５５号に記載されている。これらの特許文献の記載は、本明細書に参考として援用される。 Specific examples of the polarizer obtained by using the laminate include a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material and the resin. Examples thereof include a polarizer obtained by using a laminate with a PVA-based resin layer coated and formed on a base material. The polarizer obtained by using the laminate of the resin base material and the PVA-based resin layer coated and formed on the resin base material is, for example, a resin base material obtained by applying a PVA-based resin solution to the resin base material and drying the resin base material. It is produced by forming a PVA-based resin layer on the resin layer to obtain a laminate of a resin base material and a PVA-based resin layer; and stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer. obtain. In the present embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Further, stretching may further include, if necessary, stretching the laminate in the air at a high temperature (eg, 95 ° C. or higher) prior to stretching in boric acid aqueous solution. The obtained resin base material / polarizer laminate may be used as it is (that is, the resin base material may be used as a protective layer for the polarizer), and the resin base material is peeled off from the resin base material / polarizer laminate. Then, an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface. Details of the method for producing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The description of these patent documents is incorporated herein by reference.
　偏光子の厚みは、好ましくは１５μｍ以下であり、より好ましくは１μｍ～１２μｍであり、さらに好ましくは３μｍ～１０μｍであり、特に好ましくは３μｍ～８μｍである。偏光子の厚みがこのような範囲であれば、加熱時のカールを良好に抑制することができ、および、良好な加熱時の外観耐久性が得られる。さらに、偏光子の厚みがこのような範囲であれば、円偏光板（結果として、有機ＥＬ表示装置）の薄型化に貢献し得る。 The thickness of the polarizer is preferably 15 μm or less, more preferably 1 μm to 12 μm, further preferably 3 μm to 10 μm, and particularly preferably 3 μm to 8 μm. When the thickness of the polarizer is in such a range, curling during heating can be satisfactorily suppressed, and good appearance durability during heating can be obtained. Further, if the thickness of the polarizer is in such a range, it can contribute to the thinning of the circularly polarizing plate (as a result, the organic EL display device).
　偏光子は、好ましくは、波長３８０ｎｍ～７８０ｎｍのいずれかの波長で吸収二色性を示す。偏光子の単体透過率は、好ましくは４３．０％～４６．０％であり、より好ましくは４４．５％～４６．０％である。偏光子の偏光度は、好ましくは９７．０％以上であり、より好ましくは９９．０％以上であり、さらに好ましくは９９．９％以上である。 The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The simple substance transmittance of the polarizer is preferably 43.0% to 46.0%, more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.
Ｂ－２．保護層
　第１の保護層１２および第２の保護層１３は、それぞれ、偏光子の保護層として使用できる任意の適切なフィルムで形成される。当該フィルムの主成分となる材料の具体例としては、トリアセチルセルロース（ＴＡＣ）等のセルロース系樹脂や、ポリエステル系、ポリビニルアルコール系、ポリカーボネート系、ポリアミド系、ポリイミド系、ポリエーテルスルホン系、ポリスルホン系、ポリスチレン系、ポリノルボルネン系、ポリオレフィン系、（メタ）アクリル系、アセテート系等の透明樹脂等が挙げられる。また、（メタ）アクリル系、ウレタン系、（メタ）アクリルウレタン系、エポキシ系、シリコーン系等の熱硬化型樹脂または紫外線硬化型樹脂等も挙げられる。この他にも、例えば、シロキサン系ポリマー等のガラス質系ポリマーも挙げられる。また、特開２００１－３４３５２９号公報（ＷＯ０１／３７００７）に記載のポリマーフィルムも使用できる。このフィルムの材料としては、例えば、側鎖に置換または非置換のイミド基を有する熱可塑性樹脂と、側鎖に置換または非置換のフェニル基ならびにニトリル基を有する熱可塑性樹脂を含有する樹脂組成物が使用でき、例えば、イソブテンとＮ－メチルマレイミドからなる交互共重合体と、アクリロニトリル・スチレン共重合体とを有する樹脂組成物が挙げられる。当該ポリマーフィルムは、例えば、上記樹脂組成物の押出成形物であり得る。 B-2. Protective Layer The first protective layer 12 and the second protective layer 13 are each formed of any suitable film that can be used as a protective layer for the polarizer. Specific examples of the material that is the main component of the film include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and polysulfone-based. , Polystyrene-based, polycarbonate-based, polyolefin-based, (meth) acrylic-based, acetate-based transparent resins and the like. Further, thermosetting resins such as (meth) acrylic, urethane, (meth) acrylic urethane, epoxy, and silicone, or ultraviolet curable resins can also be mentioned. In addition to this, for example, glassy polymers such as siloxane-based polymers can also be mentioned. Further, the polymer film described in JP-A-2001-343529 (WO01 / 37007) can also be used. As the material of this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain. Can be used, and examples thereof include a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile / styrene copolymer. The polymer film can be, for example, an extruded product of the above resin composition.
　円偏光板は、後述するように代表的には画像表示装置の視認側に配置され、第１の保護層１２は、代表的にはその視認側に配置される。したがって、第１の保護層１２には、必要に応じて、ハードコート処理、反射防止処理、スティッキング防止処理、アンチグレア処理等の表面処理が施されていてもよい。さらに／あるいは、第１の保護層１２には、必要に応じて、偏光サングラスを介して視認する場合の視認性を改善する処理（代表的には、（楕）円偏光機能を付与すること、超高位相差を付与すること）が施されていてもよい。このような処理を施すことにより、偏光サングラス等の偏光レンズを介して表示画面を視認した場合でも、優れた視認性を実現することができる。したがって、円偏光板は、屋外で用いられ得る画像表示装置にも好適に適用され得る。 As will be described later, the circularly polarizing plate is typically arranged on the visible side of the image display device, and the first protective layer 12 is typically arranged on the visible side. Therefore, the first protective layer 12 may be subjected to surface treatment such as hard coat treatment, antireflection treatment, anti-sticking treatment, and anti-glare treatment, if necessary. Further / or, if necessary, the first protective layer 12 is provided with a process for improving visibility when visually recognizing through polarized sunglasses (typically, a (elliptical) circularly polarized light function is imparted. (Giving an ultra-high phase difference) may be applied. By performing such a process, excellent visibility can be realized even when the display screen is visually recognized through a polarized lens such as polarized sunglasses. Therefore, the circularly polarizing plate can be suitably applied to an image display device that can be used outdoors.
　第１の保護層の厚みは、代表的には３００μｍ以下であり、好ましくは１００μｍ以下、より好ましくは５μｍ～８０μｍ、さらに好ましくは１０μｍ～６０μｍである。なお、表面処理が施されている場合、外側保護層の厚みは、表面処理層の厚みを含めた厚みである。 The thickness of the first protective layer is typically 300 μm or less, preferably 100 μm or less, more preferably 5 μm to 80 μm, and even more preferably 10 μm to 60 μm. When the surface treatment is applied, the thickness of the outer protective layer is the thickness including the thickness of the surface treatment layer.
　第２の保護層１３は、１つの実施形態においては、光学的に等方性であることが好ましい。本明細書において「光学的に等方性である」とは、面内位相差Ｒｅ（５５０）が０ｎｍ～１０ｎｍであり、厚み方向の位相差Ｒｔｈ（５５０）が－１０ｎｍ～＋１０ｎｍであることをいう。 The second protective layer 13 is preferably optically isotropic in one embodiment. As used herein, "optically isotropic" means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is -10 nm to +10 nm. Say.
Ｃ．画像表示装置
　上記Ｂ項に記載の円偏光板は、画像表示装置に適用され得る。したがって、本発明の実施形態は、そのような円偏光板を用いた画像表示装置も包含する。画像表示装置の代表例としては、液晶表示装置、有機ＥＬ表示装置が挙げられる。本発明の実施形態による画像表示装置は、その視認側に上記Ｂ項に記載の円偏光板を備える。円偏光板は、偏光子が視認側となるように配置されている。 C. Image display device The circularly polarizing plate according to item B above can be applied to an image display device. Therefore, the embodiment of the present invention also includes an image display device using such a circularly polarizing plate. Typical examples of the image display device include a liquid crystal display device and an organic EL display device. The image display device according to the embodiment of the present invention includes the circularly polarizing plate according to the above item B on the visual side thereof. The circularly polarizing plate is arranged so that the polarizer is on the viewing side.
　以下、実施例によって本発明を具体的に説明するが、本発明はこれら実施例によって限定されるものではない。なお、各特性の測定方法は以下の通りである。 Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The measurement method of each characteristic is as follows.
（１）還元粘度
　樹脂試料を塩化メチレンに溶解させ、０．６ｇ／ｄＬの濃度の樹脂溶液を調製した。森友理化工業社製ウベローデ型粘度管を用いて、温度２０．０℃±０．１℃で測定を行い、溶媒の通過時間ｔ０及び溶液の通過時間ｔを測定した。得られたｔ０及びｔの値を用いて次式（ｉ）により相対粘度ηｒｅｌを求め、更に、得られた相対粘度ηｒｅｌを用いて次式（ii）により比粘度ηｓｐを求めた。
　　ηｒｅｌ＝ｔ／ｔ０　　・・・（ｉ）
　　ηｓｐ＝（η－η０）／η０＝ηｒｅｌ－１　　・・・（ii）
　その後、得られた比粘度ηｓｐを濃度ｃ［ｇ／ｄＬ］で割って、還元粘度ηｓｐ／ｃを求めた。この値が高いほど分子量が大きい。 (1) Reduced Viscosity A resin sample was dissolved in methylene chloride to prepare a resin solution having a concentration of 0.6 g / dL. The measurement was carried out at a temperature of 20.0 ° C. ± 0.1 ° C. using a Ubbelohde type viscosity tube manufactured by Moriyu Rika Kogyo Co., Ltd., and the solvent passage time t0 and the solution passage time t were measured. Using the obtained values of t 0 and t, the relative viscosity η ll was obtained by the following formula (i), and further, the specific viscosity η sp was obtained by the following formula (ii) using the obtained relative viscosity η ll. ..
η rel = t / t 0 ... (i)
η sp = (η-η 0 ) / η 0 = η rel -1 ・ ・ ・ (ii)
Then, the obtained specific viscosity η sp was divided by the concentration c [g / dL] to obtain the reduced viscosity η sp / c. The higher this value, the larger the molecular weight.
（２）溶融粘度
　ペレット状の樹脂を１００℃の熱風乾燥器に６時間以上入れて、乾燥させた。乾燥したペレットを用いて、東洋精機（株）製キャピラリーレオメーターで測定を行った。測定温度は２４０℃とし、剪断速度６．０８～１８２４ｓｅｃ－１間で溶融粘度を測定し、９１．２ｓｅｃ－１における溶融粘度の値を用いた。なお、オリフィスには、ダイス径１ｍｍ、長さ１０ｍｍのものを用いた。 (2) Melt Viscosity The pellet-shaped resin was placed in a hot air dryer at 100 ° C. for 6 hours or more to dry it. The dried pellets were measured with a capillary rheometer manufactured by Toyo Seiki Co., Ltd. The measurement temperature was 240 ° C., the melt viscosity was measured between a shear rate of 6.08 to 1824 sec -1 , and the value of the melt viscosity at 91.2 sec -1 was used. The orifice had a die diameter of 1 mm and a length of 10 mm.
（３）ガラス転移温度
　樹脂のガラス転移温度は、エスアイアイ・ナノテクノロジー社製示差走査熱量計ＤＳＣ６２２０を用いて測定した。約１０ｍｇの樹脂試料を同社製アルミパンに入れて密封し、５０ｍＬ／分の窒素気流下、昇温速度２０℃／分で３０℃から２００℃まで昇温した。３分間温度を保持した後、３０℃まで２０℃／分の速度で冷却した。３０℃で３分保持し、再び２００℃まで２０℃／分の速度で昇温した。２回目の昇温で得られたＤＳＣデータより、低温側のベースラインを高温側に延長した直線と、ガラス転移の階段状変化部分の曲線の勾配が最大になるような点で引いた接線との交点の温度である、補外ガラス転移開始温度を求め、それをガラス転移温度とした。 (3) Glass transition temperature The glass transition temperature of the resin was measured using a differential scanning calorimeter DSC6220 manufactured by SII Nanotechnology. About 10 mg of a resin sample was placed in an aluminum pan manufactured by the same company, sealed, and heated from 30 ° C. to 200 ° C. at a heating rate of 20 ° C./min under a nitrogen stream of 50 mL / min. After maintaining the temperature for 3 minutes, it was cooled to 30 ° C. at a rate of 20 ° C./min. The temperature was maintained at 30 ° C. for 3 minutes, and the temperature was raised again to 200 ° C. at a rate of 20 ° C./min. From the DSC data obtained by the second temperature rise, a straight line extending the baseline on the low temperature side to the high temperature side and a tangent line drawn at the point where the slope of the curve of the stepwise change part of the glass transition is maximized. The outer glass transition start temperature, which is the temperature at the intersection of the above, was determined and used as the glass transition temperature.
（４）ＧＰＣ
　樹脂試料約０．１ｇを塩化メチレン２ｍＬに溶解し、溶液を０．２μｍディスクフィルターでろ過して、ＧＰＣを測定した。標準ポリスチレンも同様にＧＰＣを測定し、ポリスチレン換算の数平均分子量（Ｍｎ）と重量平均分子量（Ｍｗ）を算出した。装置や条件は次のとおりである。
・ポンプ：ＬＣ－２０ＡＤ（（株）島津製作所製）
・デガッサー：ＤＧＵ－２０Ａ５（（株）島津製作所製）
・カラムオーブン：ＣＴＯ－２０ＡＣ（（株）島津製作所製）
・検出器：示差屈折率検出器ＲＩＤ－１０Ａ（（株）島津製作所製）
・カラム：ＰＬｇｅｌ　１０μｍ　Ｇｕａｒｄ、ＰＬｇｅｌ　１０μｍ　ＭＩＸＥＤ－Ｂ　２本（Ａｇｉｌｅｎｔ社製）
・オーブン温度：４０℃
・溶離液：クロロホルム
・流量：１ｍＬ／ｍｉｎ
・注入量：１０μＬ (4) GPC
About 0.1 g of the resin sample was dissolved in 2 mL of methylene chloride, the solution was filtered through a 0.2 μm disc filter, and GPC was measured. GPC was measured in the same manner for standard polystyrene, and polystyrene-equivalent number average molecular weight (Mn) and weight average molecular weight (Mw) were calculated. The equipment and conditions are as follows.
・ Pump: LC-20AD (manufactured by Shimadzu Corporation)
・ Degasser: DGU-20A5 (manufactured by Shimadzu Corporation)
-Column oven: CTO-20AC (manufactured by Shimadzu Corporation)
-Detector: Differential refractive index detector RID-10A (manufactured by Shimadzu Corporation)
-Columns: PLgel 10 μm Guard, PLgel 10 μm MIXED-B 2 (manufactured by Agilent)
・ Oven temperature: 40 ℃
・ Eluent: Chloroform ・ Flow rate: 1 mL / min
・ Injection amount: 10 μL
（５）屈折率
　１００℃の熱風乾燥器で６時間以上、乾燥をした樹脂ペレット約４ｇを、縦１４ｃｍ、横１４ｃｍ、厚さ０．１ｍｍのスペーサーを用い、試料の上下にポリイミドフィルムを敷いて、温度２００～２３０℃で３分間予熱し、圧力７ＭＰａで５分間加圧後、スペーサーごと取り出し、冷却してフィルムを作製した。得られたフィルムから、幅８ｍｍ、長さ４０ｍｍの長方形の試験片を切り出して測定試料とした。波長６５６ｎｍ（Ｃ線）、５８９ｎｍ（Ｄ線）、４８６ｎｍ（Ｆ線）の干渉フィルターを用いて、（株）アタゴ製多波長アッベ屈折率計ＤＲ－Ｍ４／１５５０により各波長の屈折率ｎＣ、ｎＤ、ｎＦを測定した。測定は界面液としてモノブロモナフタレンを用い、２０℃で行った。 (5) Approximately 4 g of resin pellets dried in a hot air dryer having a refractive index of 100 ° C. for 6 hours or more are spread with polyimide films on the top and bottom of the sample using spacers having a length of 14 cm, a width of 14 cm, and a thickness of 0.1 mm. , Preheated at a temperature of 200 to 230 ° C. for 3 minutes, pressurized at a pressure of 7 MPa for 5 minutes, taken out together with the spacer, and cooled to prepare a film. A rectangular test piece having a width of 8 mm and a length of 40 mm was cut out from the obtained film and used as a measurement sample. Using an interference filter with wavelengths of 656 nm (C line), 589 nm (D line), and 486 nm (F line), the refractive index of each wavelength was n C , using a multi-wavelength Abbe refractive index meter DR-M4 / 1550 manufactured by Atago Co., Ltd. n D and n F were measured. The measurement was carried out at 20 ° C. using monobromonaphthalene as the interface liquid.
（６）光弾性係数
　Ｈｅ－Ｎｅレーザー、偏光子、補償板、検光子、光検出器からなる複屈折測定装置と振動型粘弾性測定装置（レオロジー社製ＤＶＥ－３）を組み合わせた装置を用いて測定した（詳細は、日本レオロジー学会誌Ｖｏｌ．１９，ｐ９３－９７（１９９１）を参照。）。前述の（５）と同様の方法により作製したフィルムから、幅５ｍｍ、長さ２０ｍｍの試料を切り出し、粘弾性測定装置に固定し、２５℃の室温で貯蔵弾性率Ｅ’を周波数９６Ｈｚにて測定した。同時に、出射されたレーザー光を偏光子、試料、補償板、検光子の順に通し、光検出器（フォトダイオード）で拾い、ロックインアンプを通して角周波数ω又は２ωの波形について、その振幅とひずみに対する位相差を求め、ひずみ光学係数Ｏ’を求めた。このとき、偏光子と検光子の吸収軸の方向は直交し、またそれぞれ、試料の伸長方向に対してπ／４の角度をなすように調整した。光弾性係数Ｃは、貯蔵弾性率Ｅ’とひずみ光学係数Ｏ’を用いて次式より求めた。
　　　Ｃ＝Ｏ’／Ｅ’ (6) Photoelasticity A device that combines a birefringence measuring device consisting of a He-Ne laser, a polarizer, a compensator, an analyzer, and a photodetector and a viscoelastic measuring device (DVE-3 manufactured by Rheology) is used. (For details, refer to Journal of the Society of Rheology, Vol. 19, p93-97 (1991)). A sample having a width of 5 mm and a length of 20 mm was cut out from the film produced by the same method as in (5) above, fixed to a viscoelasticity measuring device, and the storage elastic modulus E'was measured at a room temperature of 25 ° C. at a frequency of 96 Hz. did. At the same time, the emitted laser light is passed through the polarizer, the sample, the compensator, and the analyzer in this order, picked up by a photodetector (photon), and passed through a lock-in amplifier for the amplitude and distortion of the waveform with an angular frequency of ω or 2ω. The phase difference was obtained, and the strain optical coefficient O'was obtained. At this time, the directions of the absorption axes of the polarizer and the analyzer were adjusted so as to be orthogonal to each other and to form an angle of π / 4 with respect to the extension direction of the sample. The photoelastic coefficient C was obtained from the following equation using the storage elastic modulus E'and the strain optical coefficient O'.
C = O'/ E'
（７）フィルムの厚み
　ダイアルゲージを用いて測定した。 (7) Film thickness Measured using a dial gauge.
（８）位相差フィルムの位相差値
　実施例および比較例で得られた位相差フィルムから５０ｍｍ×５０ｍｍのサンプルを切り出して、測定サンプルとした。この測定サンプルについて、Ａｘｏｍｅｔｒｉｃｓ社製のＡｘｏｓｃａｎを用いてＲｅ（４５０）およびＲｅ（５５０）を測定した。測定温度は２３℃であった。 (8) Phase difference value of retardation film A sample of 50 mm × 50 mm was cut out from the retardation film obtained in Examples and Comparative Examples and used as a measurement sample. Re (450) and Re (550) were measured using Axoscan manufactured by Axometrics for this measurement sample. The measurement temperature was 23 ° C.
（９）ヘイズ値
　ＪＩＳ  Ｋ　７１３６にしたがって、ヘイズメーター（村上色彩技術研究所社製、商品名「ＨＮ－１５０」）を用いて測定した。１．５％以下であれば合格と判断した。押出し混練後のペレットの時点で白濁したものは、これを用いても透明な位相差フィルムが得られないと判断し、位相差フィルムの評価は行わなかった。 (9) Haze value Measured according to JIS K 7136 using a haze meter (manufactured by Murakami Color Technology Research Institute, trade name "HN-150"). If it was 1.5% or less, it was judged to be acceptable. For pellets that became cloudy at the time of pellets after extrusion kneading, it was judged that a transparent retardation film could not be obtained even if this was used, and the retardation film was not evaluated.
（１０）破断伸びおよび限界複屈折Δｎ
　実施例および比較例で用いた長尺状の未延伸フィルムから１２０ｍｍ（製造時のフィルムの搬送方向：ＭＤ）×１５０ｍｍ（搬送方向に直交する方向：ＴＤ）のサンプルを切り出した。このサンプルを、ラボストレッチャー「Ｂｌｕｃｋｎｅｒ　ＫＡＲＯ　ＩＶ」を用いて、延伸温度を樹脂試料の「Ｔｇ－２℃」に設定し、延伸倍率を変えてＴＤ方向に固定端一軸延伸し、破断する直前の最大破断伸びを金尺にて測定した。さらに、破断しない最高延伸倍率におけるフィルムの面内位相差Ｒｅおよびフィルム厚みｄを測定し、面内位相差Ｒｅをフィルム厚みｄで除することにより、限界複屈折Δｎを求めた。フィルム厚みは、上記のとおりダイアルゲージで測定した。面内位相差Ｒｅは、Ａｘｏｍｅｔｒｉｃｓ社製の「Ａｘｏｓｃａｎ」を用いて測定した。測定波長は５９０ｎｍであった。 (10) Fracture elongation and limit birefringence Δn
A 120 mm (film transport direction at the time of manufacture: MD) × 150 mm (direction orthogonal to the transport direction: TD) was cut out from the long unstretched film used in Examples and Comparative Examples. Using a lab stretcher "Blackner KARO IV", the stretching temperature of this sample was set to "Tg-2 ° C" of the resin sample, the stretching ratio was changed, the fixed end was uniaxially stretched in the TD direction, and immediately before breaking. The maximum breaking elongation was measured with a metal scale. Further, the in-plane retardation Re and the film thickness d of the film at the maximum unbreakable draw ratio were measured, and the in-plane retardation Re was divided by the film thickness d to obtain the limit birefringence Δn. The film thickness was measured with a dial gauge as described above. The in-plane phase difference Re was measured using "Axoscan" manufactured by Axometrics. The measurement wavelength was 590 nm.
［化合物の略号］
以下の合成例、実施例および比較例で用いた化合物の略号は以下の通りである。
・ＢＰＦＭ：ビス［９－（２－フェノキシカルボニルエチル）フルオレン－９－イル］メタン
　特開２０１５－２５１１１号公報に記載の方法で合成した。
Figure JPOXMLDOC01-appb-C000011
 ・ＩＳＢ：イソソルビド［ロケットフルーレ社製］
・ＳＰＧ：スピログリコール［三菱ガス化学（株）製］
・ＤＰＣ：ジフェニルカーボネート［三菱ケミカル（株）製］
・ＢＰＥＦ：９，９－ビス（４－（２－ヒドロキシエトキシ）フェニル）フルオレン［大阪ガスケミカル（株）製］
・ＰＥＧ１０００：ポリエチレングリコール、数平均分子量１０００［三洋化成工業（株）製］ [Abbreviation of compound]
The abbreviations of the compounds used in the following synthesis examples, examples and comparative examples are as follows.
BPFM: Bis [9- (2-phenoxycarbonylethyl) fluorene-9-yl] methane It was synthesized by the method described in JP-A-2015-25111.
Figure JPOXMLDOC01-appb-C000011
・ ISB: Isosorbide [Rocket Foil]
・ SPG: Spiroglycol [manufactured by Mitsubishi Gas Chemical Company, Inc.]
・ DPC: Diphenyl carbonate [manufactured by Mitsubishi Chemical Holdings, Inc.]
-BPEF: 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene [manufactured by Osaka Gas Chemical Co., Ltd.]
-PEG1000: Polyethylene glycol, number average molecular weight 1000 [manufactured by Sanyo Chemical Industries, Ltd.]
［改質剤樹脂］
・ダイヤナールＢＲ８０（三菱ケミカル（株）製）
・ダイヤナールＢＲ８５（三菱ケミカル（株）製）
・クラリティＬＡ４２８５（（株）クラレ製）
・メタブレンＰ５７０Ａ（三菱ケミカル（株））
・エスチレンＭＳ－６００（新日鉄住金化学（株）製）
・エスチレンＭＳ－２００（新日鉄住金化学（株）製）
・Ｇ９５０４（日本ポリスチレン（株）製）
　各樹脂の組成や物性を表１に示す。 [Modifier resin]
・ Dianar BR80 (manufactured by Mitsubishi Chemical Holdings, Inc.)
・ Dianar BR85 (manufactured by Mitsubishi Chemical Holdings, Inc.)
・ Clarity LA4285 (manufactured by Kuraray Co., Ltd.)
・ Metabren P570A (Mitsubishi Chemical Co., Ltd.)
・ Estyrene MS-600 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
・ Estyrene MS-200 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
・ G9504 (manufactured by Japan Polystyrene Co., Ltd.)
Table 1 shows the composition and physical characteristics of each resin.
［実施例１］
　撹拌翼、及び還流冷却器を具備した竪型撹拌反応器２器からなるバッチ重合装置を用いて重合を行った。ＢＰＦＭを３０．３１質量部（０．０４７ｍｏｌ）、ＩＳＢを３９．９４質量部（０．２７３ｍｏｌ）、ＳＰＧを３０．２０質量部（０．０９９ｍｏｌ）、ＤＰＣを６９．６７質量部（０．３２５ｍｏｌ）、および触媒として酢酸カルシウム１水和物７．８８×１０－４質量部（４．４７×１０－６ｍｏｌ）を仕込んだ。反応器内を減圧窒素置換した後、熱媒で加温を行い、内温が１００℃になった時点で撹拌を開始した。昇温開始４０分後に内温を２２０℃に到達させ、この温度を保持するように制御すると同時に減圧を開始し、２２０℃に到達してから９０分で１３．３ｋＰａにした。重合反応とともに副生するフェノール蒸気を１１０℃の還流冷却器に導き、フェノール蒸気中に若干量含まれるモノマー成分を反応器に戻し、凝縮しないフェノール蒸気は４５℃の凝縮器に導いて回収した。第１反応器に窒素を導入して一旦大気圧まで復圧させた後、第１反応器内のオリゴマー化された反応液を第２反応器に移した。次いで、第２反応器内の昇温および減圧を開始して、４０分で内温２４０℃、圧力２０ｋＰａにした。その後、さらに圧力を下げながら、所定の攪拌動力となるまで重合を進行させた。所定動力に到達した時点で反応器に窒素を導入して復圧し、生成したポリエステルカーボネートを水中に押し出し、ストランドをカッティングしてペレットを得た。この樹脂を「ＰＣ１」と称する。各モノマーに由来する構造単位の比率は、ＢＰＦＭ／ＩＳＢ／ＳＰＧ／ＤＰＣ＝２１．５／３９．４／３０．０／９．１質量％である。ＰＣ１の還元粘度は０．４６ｄＬ／ｇ、Ｍｗは４８，０００、屈折率ｎＤは１．５２６、溶融粘度は２４８０Ｐａ・ｓ、ガラス転移温度は１３９℃、光弾性係数は９×１０－１２［ｍ２／Ｎ］、波長分散Ｒｅ（４５０）／Ｒｅ（５５０）は０．８５であった。 [Example 1]
Polymerization was carried out using a batch polymerization apparatus consisting of two vertical stirring reactors equipped with a stirring blade and a reflux condenser. BPFM is 30.31 parts by mass (0.047 mol), ISB is 39.94 parts by mass (0.273 mol), SPG is 30.20 parts by mass (0.099 mol), and DPC is 69.67 parts by mass (0.325 mol). ), And 7.88 × 10 -4 parts by mass (4.47 × 10 -6 mol) of calcium acetate monohydrate was charged as a catalyst. After substituting nitrogen under reduced pressure in the reactor, heating was performed with a heat medium, and stirring was started when the internal temperature reached 100 ° C. The internal temperature was brought to 220 ° C. 40 minutes after the start of the temperature rise, and the depressurization was started at the same time as controlling to maintain this temperature, and the temperature was adjusted to 13.3 kPa 90 minutes after reaching 220 ° C. The phenol vapor produced as a by-product of the polymerization reaction was guided to a reflux condenser at 110 ° C., the monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the uncondensed phenol vapor was guided to a condenser at 45 ° C. for recovery. Nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, and then the oligomerized reaction solution in the first reactor was transferred to the second reactor. Then, the temperature rise and depressurization in the second reactor were started, and the internal temperature was 240 ° C. and the pressure was 20 kPa in 40 minutes. Then, while further reducing the pressure, the polymerization was allowed to proceed until a predetermined stirring power was obtained. When the predetermined power was reached, nitrogen was introduced into the reactor to repressurize, the produced polyester carbonate was extruded into water, and the strands were cut to obtain pellets. This resin is referred to as "PC1". The ratio of structural units derived from each monomer is BPFM / ISB / SPG / DPC = 21.5 / 39.4 / 30.0 / 9.1% by mass. The reduced viscosity of PC1 is 0.46 dL / g, Mw 48,000, refractive index n D is 1.526, a melt viscosity of 2480Pa · s, a glass transition temperature of 139 ° C., the photoelastic coefficient of 9 × 10 -12 [ m 2 / N] and the wavelength dispersion Re (450) / Re (550) were 0.85.
　アクリル系樹脂としてＢＲ８０を用いて、得られたポリエステルカーボネートとの押出混錬を行った。ポリカーボネートのペレット（９９．５質量部）とＢＲ８０の粉（０．５質量部）を混ぜ合わせたものを定量フィーダーを用いて、（株）日本製鋼所製の二軸押出機ＴＥＸ３０ＨＳＳに投入した。押出機シリンダー温度は２５０℃に設定し、処理量１２ｋｇ／ｈｒ、スクリュー回転数１２０ｒｐｍで押出を行った。また、押出機には真空ベントが具備されており、溶融樹脂を減圧脱揮しながら押出した。このようにして得られた樹脂組成物のペレットを、１００℃で６時間以上、真空乾燥をした後、単軸押出機（いすず化工機社製、スクリュー径２５ｍｍ、シリンダー設定温度：２５０℃）、Ｔダイ（幅３００ｍｍ、設定温度：２２０℃）、チルロール（設定温度：１２０～１３０℃）および巻取機を備えたフィルム製膜装置を用いて、長さ３ｍ、幅２００ｍｍ、厚み１００μｍの長尺未延伸フィルムを作製した。次いで、この長尺未延伸フィルムを用い、上記（１０）に記載の手順により破断伸びおよび限界複屈折Δｎを求めた。また、前述の評価に供したフィルムとは別に、延伸温度をＴｇ、延伸倍率２．４倍として得られた位相差フィルムは、ｎｘ＞ｎｙ＞ｎｚの屈折率特性を示した。さらに、得られた位相差フィルムのＲｅ（５５０）は１４５ｎｍ、Ｒｅ（４５０）／Ｒｅ（５５０）は０．８５であり、ヘイズは０．３％であった。結果を表１に示す。 Using BR80 as an acrylic resin, extrusion kneading with the obtained polyester carbonate was performed. A mixture of polycarbonate pellets (99.5 parts by mass) and BR80 powder (0.5 parts by mass) was put into a twin-screw extruder TEX30HSS manufactured by Japan Steel Works, Ltd. using a quantitative feeder. The extruder cylinder temperature was set to 250 ° C., and extrusion was performed at a processing rate of 12 kg / hr and a screw rotation speed of 120 rpm. Further, the extruder is equipped with a vacuum vent, and the molten resin is extruded while devolatile under reduced pressure. The pellets of the resin composition thus obtained are vacuum-dried at 100 ° C. for 6 hours or more, and then a single-screw extruder (manufactured by Isuzu Kakohki Co., Ltd., screw diameter 25 mm, cylinder set temperature: 250 ° C.). Using a film-forming device equipped with a T-die (width 300 mm, set temperature: 220 ° C.), chill roll (set temperature: 120-130 ° C.), and a winder, a long length of 3 m in length, 200 mm in width, and 100 μm in thickness. An unstretched film was prepared. Next, using this long unstretched film, the elongation at break and the limit birefringence Δn were determined by the procedure described in (10) above. Further, apart from the film used for the above evaluation, the retardation film obtained at a stretching temperature of Tg and a stretching magnification of 2.4 times exhibited a refractive index characteristic of nx> ny> nz. Further, the Re (550) of the obtained retardation film was 145 nm, the Re (450) / Re (550) was 0.85, and the haze was 0.3%. The results are shown in Table 1.
［実施例２］
　ＢＲ８０の配合比を０．７質量％としたこと以外は実施例１と同様にして位相差フィルムを作製した。得られた位相差フィルムを実施例１と同様の評価に供した。結果を表１に示す。 [Example 2]
A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 0.7% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
［実施例３］
　ＢＲ８０の配合比を０．９質量％としたこと以外は実施例１と同様にして位相差フィルムを作製した。得られた位相差フィルムを実施例１と同様の評価に供した。結果を表１に示す。 [Example 3]
A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 0.9% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
［実施例４］
　ＢＲ８０の配合比を１．５質量％としたこと以外は実施例１と同様にして位相差フィルムを作製した。得られた位相差フィルムを実施例１と同様の評価に供した。結果を表１に示す。 [Example 4]
A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 1.5% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
［比較例１］
　アクリル系樹脂を用いなかったこと（すなわち、アクリル系樹脂の含有量をゼロとしたこと）および延伸温度をＴｇ＋２℃としたこと以外は実施例１と同様にして位相差フィルムを作製した。得られた位相差フィルムを実施例１と同様の評価に供した。結果を表１に示す。 [Comparative Example 1]
A retardation film was produced in the same manner as in Example 1 except that an acrylic resin was not used (that is, the content of the acrylic resin was set to zero) and the stretching temperature was set to Tg + 2 ° C. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
［比較例２］
　ＢＲ８０の配合比を０．３質量％としたこと以外は実施例１と同様にして位相差フィルムを作製した。得られた位相差フィルムを実施例１と同様の評価に供した。結果を表１に示す。 [Comparative Example 2]
A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 0.3% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
［比較例３］
　ＢＲ８０の配合比を３．０質量％としたこと以外は実施例１と同様にして位相差フィルムを作製した。得られた位相差フィルムを実施例１と同様の評価に供した。結果を表１に示す。 [Comparative Example 3]
A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 3.0% by mass. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
［比較例４］
　ＢＲ８０の配合比を１０質量％としたことおよび延伸温度をＴｇ＋２℃とした以外は実施例１と同様にして位相差フィルムを作製した。得られた位相差フィルムを実施例１と同様の評価に供した。結果を表１に示す。 [Comparative Example 4]
A retardation film was produced in the same manner as in Example 1 except that the compounding ratio of BR80 was 10% by mass and the stretching temperature was Tg + 2 ° C. The obtained retardation film was subjected to the same evaluation as in Example 1. The results are shown in Table 1.
［比較例５］
　アクリル系樹脂としてＢＲ８５を用いて、ＢＲ８５の配合比を１質量％としたこと以外は実施例１と同様にして押出混錬と未延伸フィルムの作製を行った。未延伸フィルムは一見、透明であったが、細かい不溶成分が発生していた。 [Comparative Example 5]
BR85 was used as the acrylic resin, and extrusion kneading and unstretched film were produced in the same manner as in Example 1 except that the compounding ratio of BR85 was 1% by mass. The unstretched film was seemingly transparent, but fine insoluble components were generated.
［比較例６］
　アクリル系樹脂としてＬＡ４２８５を用いて、ＬＡ４２８５の配合比を１質量％としたこと以外は実施例１と同様にして押出混錬を行った。混錬後のペレットは白濁していた。 [Comparative Example 6]
LA4285 was used as the acrylic resin, and extrusion kneading was carried out in the same manner as in Example 1 except that the blending ratio of LA4285 was 1% by mass. The pellets after kneading were cloudy.
［比較例７］
　アクリル系樹脂としてＰ５７０Ａを用いて、Ｐ５７０Ａの配合比を１質量％としたこと以外は実施例１と同様にして押出混錬を行った。混錬後のペレットは白濁していた。 [Comparative Example 7]
Extrusion kneading was carried out in the same manner as in Example 1 except that P570A was used as the acrylic resin and the blending ratio of P570A was 1% by mass. The pellets after kneading were cloudy.
［比較例８］
　アクリル系樹脂としてＭＳ－６００を用いて、ＭＳ－６００の配合比を１質量％としたこと以外は実施例１と同様の評価に供した。結果を表１に示す。 [Comparative Example 8]
MS-600 was used as the acrylic resin, and the same evaluation as in Example 1 was performed except that the compounding ratio of MS-600 was 1% by mass. The results are shown in Table 1.
［比較例９］
　アクリル系樹脂としてＭＳ－２００を用いて、ＭＳ－２００の配合比を１質量％としたこと以外は実施例１と同様にして押出混錬を行った。混錬後のペレットは白濁していた。 [Comparative Example 9]
Extrusion kneading was carried out in the same manner as in Example 1 except that MS-200 was used as the acrylic resin and the blending ratio of MS-200 was 1% by mass. The pellets after kneading were cloudy.
［比較例１０］
　改質剤樹脂として非アクリル系樹脂のＧ９５０４を用いて、Ｇ９５０４の配合比を１質量％としたこと以外は実施例１と同様にして押出混錬を行った。混錬後のペレットは白濁していた。 [Comparative Example 10]
Extrusion kneading was carried out in the same manner as in Example 1 except that G9504, a non-acrylic resin, was used as the modifier resin and the blending ratio of G9504 was 1% by mass. The pellets after kneading were cloudy.
［比較例１１］
　特開２０１４－４３５７０号公報に記載の方法で、ＢＰＥＦ／ＩＳＢ／ＰＥＧ１０００共重合ポリカーボネートを合成した。この樹脂を「ＰＣ２」と称する。各モノマーに由来する構造単位の比率は、ＢＰＥＦ／ＩＳＢ／ＰＥＧ１０００／ＤＰＣ＝６３．７／２６．１／１．０／９．２質量％である。ＰＣ２の還元粘度は０．３５ｄＬ／ｇ、Ｍｗは３６，０００、屈折率ｎＤは１．５９９、溶融粘度は３１００Ｐａ・ｓ、ガラス転移温度は１４５℃、光弾性係数は３０×１０－１２［ｍ２／Ｎ］、波長分散Ｒｅ（４５０）／Ｒｅ（５５０）は０．８９であった。ベース樹脂としてＰＣ２を用い、アクリル系樹脂としてＢＲ８０を用いて、ＢＲ８０の配合比を１質量％としたこと以外は実施例１と同様にして押出混錬を行った。混錬後のペレットは白濁していた。 [Comparative Example 11]
BPEF / ISB / PEG1000 copolymerized polycarbonate was synthesized by the method described in JP-A-2014-435570. This resin is referred to as "PC2". The ratio of structural units derived from each monomer is BPEF / ISB / PEG1000 / DPC = 63.7 / 26.1 / 1.0 / 9.2% by mass. The reduced viscosity of PC2 is 0.35 dL / g, Mw is 36,000, refractive index nD is 1.599, melt viscosity is 3100 Pa · s, glass transition temperature is 145 ° C, and photoelastic coefficient is 30 × 10-12 [m. 2 / N], the wavelength dispersion Re (450) / Re (550) was 0.89. Extrusion kneading was carried out in the same manner as in Example 1 except that PC2 was used as the base resin and BR80 was used as the acrylic resin and the blending ratio of BR80 was 1% by mass. The pellets after kneading were cloudy.
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
［評価］
　表１から明らかなように、本発明の実施例によれば、最適な組成、分子量のアクリル系樹脂を用いることにより、破断伸びが大きく（すなわち、伸張性に優れ）、限界複屈折が大きく（すなわち、位相差発現性に優れ）、かつ、ヘイズの小さい逆分散位相差フィルムを得ることができる。アクリル系樹脂の添加量が０．５質量％未満である比較例１および２は、破断伸びが小さく（すなわち、十分に延伸できず）、限界複屈折Δｎが実施例に比べて顕著に小さいことがわかる。一方、アクリル系樹脂の添加量が２．０質量％を超える比較例３および４は、ヘイズが高く、透明性が不十分であり、さらにアクリル系樹脂の添加量が多すぎると、限界複屈折はかえって低下することがわかる。比較例６～１０より、メタクリル酸メチル以外の成分を多く含有するアクリル系樹脂、及び非アクリル系樹脂では、本発明の樹脂とは相溶性を持たないために、光学フィルムとして求められる樹脂の透明性が得られないことがわかる。なお、比較例８については押出後の樹脂組成物は透明であったが、延伸した後にヘイズが上昇した。これはポリエステルカーボネート樹脂とＭＳ－６００は屈折率が近いために、外観上は透明になっていたが、実質的には非相溶で相分離しているため、延伸という大変形を加えると、相間剥離が生じてヘイズが上昇したことが考えられる。 [Evaluation]
As is clear from Table 1, according to the examples of the present invention, by using an acrylic resin having an optimum composition and molecular weight, the elongation at break is large (that is, the extensibility is excellent) and the limit birefringence is large (that is, the limit birefringence is large (that is, excellent extensibility). That is, it is possible to obtain a inversely dispersed retardation film having excellent retardation (excellent retardation) and a small haze. In Comparative Examples 1 and 2 in which the amount of the acrylic resin added was less than 0.5% by mass, the elongation at break was small (that is, it could not be sufficiently stretched), and the limit birefringence Δn was significantly smaller than that of the examples. I understand. On the other hand, in Comparative Examples 3 and 4 in which the amount of the acrylic resin added exceeds 2.0% by mass, the haze is high, the transparency is insufficient, and if the amount of the acrylic resin added is too large, the limit birefringence is reached. On the contrary, it can be seen that it decreases. From Comparative Examples 6 to 10, the acrylic resin and the non-acrylic resin containing a large amount of components other than methyl methacrylate are not compatible with the resin of the present invention, and therefore, the resin required as an optical film is transparent. It turns out that sex cannot be obtained. In Comparative Example 8, the resin composition after extrusion was transparent, but the haze increased after stretching. This is because the polyester carbonate resin and MS-600 have similar refractive indexes, so they are transparent in appearance, but they are practically incompatible and phase-separated. It is probable that interphase separation occurred and the haze increased.
［実施例５］
（偏光子の作製）
　厚み３０μｍのポリビニルアルコール（ＰＶＡ）系樹脂フィルム（クラレ製、製品名「ＰＥ３０００」）の長尺ロールを、ロール延伸機により長手方向に５．９倍になるように長手方向に一軸延伸しながら同時に膨潤、染色、架橋、洗浄処理を施し、最後に乾燥処理を施すことにより厚み１２μｍの偏光子を作製した。
　具体的には、膨潤処理は２０℃の純水で処理しながら２．２倍に延伸した。次いで、染色処理は得られる偏光子の単体透過率が４５．０％になるようにヨウ素濃度が調整されたヨウ素とヨウ化カリウムの重量比が１：７である３０℃の水溶液中において処理しながら１．４倍に延伸した。更に、架橋処理は、２段階の架橋処理を採用し、１段階目の架橋処理は４０℃のホウ酸とヨウ化カリウムを溶解した水溶液において処理しながら１．２倍に延伸した。１段階目の架橋処理の水溶液のホウ酸含有量は５．０重量％で、ヨウ化カリウム含有量は３．０重量％とした。２段階目の架橋処理は６５℃のホウ酸とヨウ化カリウムを溶解した水溶液において処理しながら１．６倍に延伸した。２段階目の架橋処理の水溶液のホウ酸含有量は４．３重量％で、ヨウ化カリウム含有量は５．０重量％とした。また、洗浄処理は、２０℃のヨウ化カリウム水溶液で処理した。洗浄処理の水溶液のヨウ化カリウム含有量は２．６重量％とした。最後に、乾燥処理は７０℃で５分間乾燥させて偏光子を得た。 [Example 5]
(Making a polarizer)
A long roll of a polyvinyl alcohol (PVA) -based resin film (manufactured by Kuraray, product name "PE3000") having a thickness of 30 μm is uniaxially stretched in the longitudinal direction so as to be 5.9 times in the longitudinal direction by a roll stretching machine at the same time. A polarizer having a thickness of 12 μm was prepared by performing swelling, dyeing, cross-linking, and washing treatment, and finally performing a drying treatment.
Specifically, the swelling treatment was carried out by stretching 2.2 times while treating with pure water at 20 ° C. Next, the dyeing treatment was carried out in an aqueous solution at 30 ° C. in which the weight ratio of iodine and potassium iodide was adjusted so that the simple substance transmittance of the obtained polarizer was 45.0% and the weight ratio was 1: 7. However, it was stretched 1.4 times. Further, the cross-linking treatment adopted a two-step cross-linking treatment, and the first-step cross-linking treatment was carried out 1.2 times while being treated with an aqueous solution in which boric acid and potassium iodide were dissolved at 40 ° C. The boric acid content of the aqueous solution of the first-step cross-linking treatment was 5.0% by weight, and the potassium iodide content was 3.0% by weight. The second-step cross-linking treatment was carried out 1.6 times while treating with an aqueous solution in which boric acid and potassium iodide were dissolved at 65 ° C. The boric acid content of the aqueous solution of the second step cross-linking treatment was 4.3% by weight, and the potassium iodide content was 5.0% by weight. The washing treatment was carried out with an aqueous potassium iodide solution at 20 ° C. The potassium iodide content of the aqueous solution of the washing treatment was set to 2.6% by weight. Finally, the drying treatment was carried out at 70 ° C. for 5 minutes to obtain a polarizer.
（偏光板の作製）
　上記偏光子の片側に、ポリビニルアルコール系接着剤を介して、トリアセチルセルロースフィルム（厚み４０μｍ、コニカミノルタ社製、商品名「ＫＣ４ＵＹＷ」）を貼り合わせ、保護層／偏光子の構成を有する偏光板を得た。 (Preparation of polarizing plate)
A triacetyl cellulose film (thickness 40 μm, manufactured by Konica Minolta, trade name “KC4UYW”) is attached to one side of the above-mentioned polarizing element via a polyvinyl alcohol-based adhesive, and a polarizing plate having a protective layer / polarizer configuration is attached. Got
（円偏光板の作製）
　上記で得られた偏光板の偏光子面とＲｅ（５５０）が１４０ｎｍとなるよう延伸倍率を調整したこと以外は実施例１と同様にして作成した位相差フィルムとを、アクリル系粘着剤を介して貼り合わせた。なお、位相差フィルムは、貼り合せた際に、その遅相軸と偏光子の吸収軸が４５度の角度をなすように切り出した。また偏光子の吸収軸は長手方向に平行となるように配置した。このようにして、保護層／偏光子／位相差フィルムの構成を有する円偏光板を得た。 (Preparation of circularly polarizing plate)
The polarizing element surface of the polarizing plate obtained above and the retardation film prepared in the same manner as in Example 1 except that the stretching ratio was adjusted so that Re (550) was 140 nm were passed through an acrylic pressure-sensitive adhesive. And pasted together. The retardation film was cut out so that its slow axis and the absorption axis of the polarizer formed an angle of 45 degrees when they were bonded together. The absorption axes of the polarizers were arranged so as to be parallel to the longitudinal direction. In this way, a circularly polarizing plate having a protective layer / polarizer / retardation film configuration was obtained.
（画像表示装置の作製）
　市販の有機ＥＬ表示装置（Ｓａｍｓｕｎｇ社製、製品名「Ｇａｌａｘｙ  ５」）から有機ＥＬパネルを取り出し、この有機ＥＬパネルに貼り付けられている偏光フィルムを剥がし取り、代わりに、上記で得られた円偏光板を貼り合わせて画像表示装置（有機ＥＬ表示装置）を得た。得られた有機ＥＬ表示装置を全面黒表示させ、目視により画像（黒表示画面）を観察した。画像は反射が少なく、かつ、所望でない色付きも認められない、良好なものであった。 (Manufacturing of image display device)
The organic EL panel is taken out from a commercially available organic EL display device (manufactured by Samsung, product name "Galaxy 5"), the polarizing film attached to the organic EL panel is peeled off, and instead, the circle obtained above is used. A polarizing plate was attached to obtain an image display device (organic EL display device). The obtained organic EL display device was displayed in black on the entire surface, and the image (black display screen) was visually observed. The image was good with little reflection and no unwanted coloring.
　本発明の位相差フィルムは円偏光板に好適に用いられ得、円偏光板は画像表示装置（代表的には、液晶表示装置、有機ＥＬ表示装置）に好適に用いられ得る。 The retardation film of the present invention can be suitably used for a circularly polarizing plate, and the circularly polarizing plate can be suitably used for an image display device (typically, a liquid crystal display device or an organic EL display device).
　１０　　　偏光板
　１１　　　偏光子
　１２　　　第１の保護層
　１３　　　第２の保護層
　２０　　　位相差フィルム
１００　　　円偏光板
１０１　　　円偏光板 10 Polarizing plate 11 Polarizer 12 First protective layer 13 Second protective layer 20 Phase difference film 100 Circularly polarizing plate 101 Circularly polarizing plate

Claims (11)

  1. 　カーボネート結合およびエステル結合からなる群から選択される少なくとも１つの結合基と、下記一般式（１）で表される構造単位および下記一般式（２）で表される構造単位からなる群から選択される少なくとも１つの構造単位とを含み、正の屈折率異方性を有する樹脂と；アクリル系樹脂と；を含有し、
    　該アクリル系樹脂の含有量が０．５質量％～２．０質量％であり、
    　該アクリル系樹脂が、メタクリル酸メチル由来の構造単位を７０質量％以上含有し、その重量平均分子量Ｍｗが１０，０００～２００，０００であり、
    　Ｒｅ（５５０）が１００ｎｍ～２００ｎｍであり、Ｒｅ（４５０）／Ｒｅ（５５０）が０．５を超えて１．０未満である、位相差フィルム：
    Figure JPOXMLDOC01-appb-C000001
    Figure JPOXMLDOC01-appb-C000002
     一般式（１）および（２）中、Ｒ１～Ｒ３は、それぞれ独立に、直接結合、置換または非置換の炭素数１～４のアルキレン基であり、Ｒ４～Ｒ９は、それぞれ独立に、水素原子、置換または非置換の炭素数１～１０のアルキル基、置換または非置換の炭素数４～１０のアリール基、置換または非置換の炭素数１～１０のアシル基、置換または非置換の炭素数１～１０のアルコキシ基、置換または非置換の炭素数１～１０のアリールオキシ基、置換または非置換のアミノ基、置換または非置換の炭素数１～１０のビニル基、置換または非置換の炭素数１～１０のエチニル基、置換基を有する硫黄原子、置換基を有するケイ素原子、ハロゲン原子、ニトロ基、またはシアノ基であり；ただし、Ｒ４～Ｒ９は、互いに同一であっても、異なっていてもよく、 Ｒ４～Ｒ９のうち隣接する少なくとも２つの基が互いに結合して環を形成していてもよく；
    　Ｒｅ（５５０）は、２３℃における波長５５０ｎｍの光で測定したフィルムの面内位相差であり、Ｒｅ（４５０）は、２３℃における波長４５０ｎｍの光で測定したフィルムの面内位相差である。     Selected from a group consisting of at least one bonding group selected from the group consisting of a carbonate bond and an ester bond, and a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2). A resin having a positive refractive index anisotropy; an acrylic resin;
    The content of the acrylic resin is 0.5% by mass to 2.0% by mass.
    The acrylic resin contains 70% by mass or more of a structural unit derived from methyl methacrylate, and has a weight average molecular weight Mw of 10,000 to 200,000.
    Re (550) is 100 nm to 200 nm, Re (450) / Re (550) is more than 0.5 and less than 1.0, retardation film:
    Figure JPOXMLDOC01-appb-C000001
    Figure JPOXMLDOC01-appb-C000002
     In the general formulas (1) and (2), R 1 to R 3 are independently bonded, substituted or unsubstituted alkylene groups having 1 to 4 carbon atoms, and R 4 to R 9 are independent of each other. , Hydrogen atom, substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted aryl group having 4 to 10 carbon atoms, substituted or unsubstituted acyl group having 1 to 10 carbon atoms, substituted or unsubstituted. Substituted alkoxy group with 1-10 carbon atoms, substituted or unsubstituted aryloxy group with 1-10 carbon atoms, substituted or unsubstituted amino group, substituted or unsubstituted vinyl group with 1-10 carbon atoms, substituted or unsubstituted It is an unsubstituted ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group, or a cyano group; however, R 4 to R 9 are the same as each other. It may be present or different, and at least two adjacent groups of R 4 to R 9 may be bonded to each other to form a ring;
    Re (550) is the in-plane phase difference of the film measured with light having a wavelength of 550 nm at 23 ° C., and Re (450) is the in-plane phase difference of the film measured with light having a wavelength of 450 nm at 23 ° C.
  2. 　前記正の屈折率異方性を有する樹脂が、前記一般式（１）で表される構造単位および前記一般式（２）で表される構造単位からなる群から選択される少なくとも１つの構造単位を１質量％～４０質量％含有する、請求項１に記載の位相差フィルム。 At least one structural unit in which the resin having positive refractive index anisotropy is selected from the group consisting of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2). The retardation film according to claim 1, which contains 1% by mass to 40% by mass of.
  3. 　前記正の屈折率異方性を有する樹脂が、下記一般式（３）で表される構造単位をさらに含む、請求項１または２に記載の位相差フィルム。
    Figure JPOXMLDOC01-appb-C000003
         The retardation film according to claim 1 or 2, wherein the resin having positive refractive index anisotropy further contains a structural unit represented by the following general formula (3).
    Figure JPOXMLDOC01-appb-C000003
  4. 　前記正の屈折率異方性を有する樹脂が、下記一般式（４）で表される構造単位をさらに含む、請求項１から３のいずれかに記載の位相差フィルム。
    Figure JPOXMLDOC01-appb-C000004
         The retardation film according to any one of claims 1 to 3, wherein the resin having positive refractive index anisotropy further contains a structural unit represented by the following general formula (4).
    Figure JPOXMLDOC01-appb-C000004
  5. 　ヘイズ値が１．５％以下である、請求項１から４のいずれかに記載の位相差フィルム。 The retardation film according to any one of claims 1 to 4, wherein the haze value is 1.5% or less.
  6. 　破断伸びが２００％以上である、請求項１から５のいずれかに記載の位相差フィルム。 The retardation film according to any one of claims 1 to 5, wherein the elongation at break is 200% or more.
  7. 　限界複屈折Δｎが０．００３９以上である、請求項１から６のいずれかに記載の位相差フィルム。 The retardation film according to any one of claims 1 to 6, wherein the limit birefringence Δn is 0.0039 or more.
  8. 　請求項１から７のいずれかに記載の位相差フィルムの製造方法であって、
    　前記正の屈折率異方性を有する樹脂と前記アクリル系樹脂とを含有する樹脂フィルムを延伸することを含み、
    　該延伸が、該正の屈折率異方性を有する樹脂のガラス転移温度以下の温度で行われる、
    　方法。     The method for producing a retardation film according to any one of claims 1 to 7.
    Includes stretching a resin film containing the resin having positive refractive index anisotropy and the acrylic resin.
    The stretching is carried out at a temperature equal to or lower than the glass transition temperature of the resin having positive refractive index anisotropy.
    Method.
  9. 　前記延伸が、長尺状の前記樹脂フィルムを長尺方向に搬送しながら行われ、
    　得られる長尺状の位相差フィルムの遅相軸方向が、長尺方向に対して４０°～５０°または１３０°～１４０°の方向である、
    　請求項８に記載の位相差フィルムの製造方法。     The stretching is performed while transporting the long resin film in the long direction.
    The slow axis direction of the obtained elongated retardation film is 40 ° to 50 ° or 130 ° to 140 ° with respect to the elongated direction.
    The method for producing a retardation film according to claim 8.
  10. 　偏光子と請求項１から７のいずれかに記載の位相差フィルムとを有し、
    　該偏光子の吸収軸と該位相差フィルムの遅相軸とのなす角度が４０°～５０°または１３０°～１４０°である、
    　円偏光板。     It has a polarizer and the retardation film according to any one of claims 1 to 7.
    The angle formed by the absorption axis of the polarizer and the slow axis of the retardation film is 40 ° to 50 ° or 130 ° to 140 °.
    Circularly polarized light.
  11. 　請求項１０に記載の円偏光板を視認側に備え、該円偏光板の偏光子が視認側に配置されている、画像表示装置。 An image display device in which the circularly polarizing plate according to claim 10 is provided on the viewing side, and the polarizer of the circularly polarizing plate is arranged on the viewing side.
PCT/JP2020/038470 2019-10-21 2020-10-12 Phase difference film, method for manufacturing same; and circularly polarizing plate and image display device using said phase difference film WO2021079773A1 (en)

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