WO2013137123A1 - Film à différence de phase lambda/4, plaque de polarisation circulaire et dispositif d'affichage électroluminescent organique - Google Patents

Film à différence de phase lambda/4, plaque de polarisation circulaire et dispositif d'affichage électroluminescent organique Download PDF

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WO2013137123A1
WO2013137123A1 PCT/JP2013/056392 JP2013056392W WO2013137123A1 WO 2013137123 A1 WO2013137123 A1 WO 2013137123A1 JP 2013056392 W JP2013056392 W JP 2013056392W WO 2013137123 A1 WO2013137123 A1 WO 2013137123A1
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film
stretching
retardation film
group
retardation
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PCT/JP2013/056392
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English (en)
Japanese (ja)
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賢治 三島
理英子 れん
田代　耕二
幸仁 中澤
範江 谷原
翠 木暮
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コニカミノルタ株式会社
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Priority to KR1020147025074A priority Critical patent/KR101636189B1/ko
Publication of WO2013137123A1 publication Critical patent/WO2013137123A1/fr

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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
    • 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
    • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
    • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
    • B29C55/14—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial successively
    • 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
    • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
    • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
    • B29C55/16—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial simultaneously
    • 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
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent
    • B29K2995/0034—Polarising
    • 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
    • C08J2301/00—Characterised by the use of cellulose, modified cellulose or cellulose derivatives
    • C08J2301/08—Cellulose derivatives
    • C08J2301/10—Esters of organic acids
    • C08J2301/12—Cellulose acetate

Definitions

  • the present invention relates to a ⁇ / 4 retardation film, a circularly polarizing plate having the same, and an organic electroluminescence display device.
  • a stretched film obtained by stretching a resin film is used as an optical material of a component of a display device by utilizing its optical anisotropy.
  • the stretched film can be used as a retardation film for optical compensation such as coloring prevention and viewing angle expansion, or the stretched film and a polarizer can be bonded together to be used as a polarizing plate.
  • the stretched film and a polarizer can be bonded together to be used as a polarizing plate.
  • the retardation film has been required for improving the display quality of an organic electroluminescence display device (also referred to as an organic EL display device).
  • an organic EL display device In the organic EL display device, there is a problem that external light is reflected by the cell electrode and the image becomes whitish.
  • a retardation film having an in-plane retardation value of 1/4 of the wavelength of visible light (sometimes simply referred to as retardation value or retardation value) (hereinafter referred to as ⁇ / 4 retardation film).
  • ⁇ / 4 retardation film An attempt has been made to provide a circularly polarizing plate on which a polarizer is bonded on the viewing side (see Patent Document 1).
  • the reverse wavelength dispersibility having a retardation value of ⁇ / 4 in the entire wavelength region refers to a wavelength dispersion characteristic having a larger retardation value for longer wavelengths. This is because if the retardation film does not have a retardation value of 1/4 for a certain wavelength, the external light of the color corresponding to that wavelength is reflected by the cell electrode of the organic EL display device. This is because the image is tinged with the color.
  • Patent Document 2 a technique for controlling chromatic dispersion characteristics by making a chromatic dispersion adjusting agent have a specific molecular structure has been reported (see Patent Document 2).
  • the molecular absorption wavelength derived from the transition electric dipole moment in the direction y orthogonal to the long axis direction x of the molecular structure of the wavelength dispersion adjusting agent is in a direction substantially parallel to the molecular long axis (x) direction.
  • a wavelength dispersion adjusting agent having a molecular structure that is longer than the molecular absorption wavelength derived from the transition electric dipole moment is described.
  • the conventional chromatic dispersion adjusting agent has a trade-off relationship between the retardation development property and the reverse wavelength dispersion property, so that a high retardation value like a ⁇ / 4 retardation film required for a circularly polarizing plate is developed.
  • it has been necessary to take measures such as thickening the film, adding a phase difference developing agent, or making a resin having high phase difference such as polycarbonate resin.
  • the present invention has been made in view of the above-described problems and situations, and a problem to be solved is to provide a ⁇ / 4 retardation film having high retardation development and good reverse wavelength dispersion. Moreover, it is providing the circularly-polarizing plate and organic electroluminescent display apparatus which comprised it.
  • the ⁇ / 4 retardation film contains a compound bonded with a linking group having a linking site at least at three locations, And the half width ( ⁇ xmax) of the absorption band of the maximum absorption wavelength belonging to the longest group (main chain x) among the groups bonded through the linking group, and at least one of the other linking sites of the linking group
  • the phase difference is highly expressed, and the reverse wavelength dispersibility is high.
  • the present inventors have found that a good ⁇ / 4 retardation film can be realized and have reached the present invention.
  • the half width ( ⁇ ymax) of the band is given by the following formula (1) Characterized by foot lambda / 4 phase difference film.
  • the stretching is orthogonal while stretching within the range of 70 to 95% of the total stretching process.
  • a circularly polarizing plate comprising the ⁇ / 4 retardation film according to any one of items 1 to 7 above.
  • An organic electroluminescence display device comprising the ⁇ / 4 retardation film according to any one of items 1 to 7 above.
  • the above-mentioned means of the present invention can provide a ⁇ / 4 retardation film having high retardation and good reverse wavelength dispersion. Moreover, the circularly-polarizing plate and organic electroluminescent display apparatus which comprise it can be provided.
  • the expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
  • the half-value width ( ⁇ ymax) of the absorption band of the maximum absorption wavelength ( ⁇ ymax) attributed to the side chain y is twice or more than the half-value width ( ⁇ xmax) of the absorption band of the maximum absorption wavelength ( ⁇ xmax) assigned to the main chain x
  • the forward wavelength dispersion of the refractive index in the side chain direction can be increased.
  • the reverse wavelength dispersion of the in-plane retardation value Ro of the retardation film can be set to a desired value.
  • the ⁇ / 4 retardation film of the present invention has an in-plane retardation value at a measurement wavelength ⁇ (nm) in an environment of a temperature of 23 ° C. and a relative humidity of 55%, and Ro (450) / ⁇ / 4 position having chromatic dispersion characteristics in which Ro (550) is in the range of 0.72 to 0.96 and Ro (550) / Ro (650) is in the range of 0.83 to 0.98 It is a retardation film, and the ⁇ / 4 retardation film contains a compound bonded with a linking group having a linking site in at least three places, and is the longest group among the groups bonded through the linking group ( The half-width ( ⁇ xmax) of the absorption band of the maximum absorption wavelength ( ⁇ xmax) belonging to the main chain x) and the group (side chain y) bonded to at least one linking site of the linking group.
  • Half width of the absorption band of the assigned maximum absorption wavelength ( ⁇ ymax) Derutaramudaymax) and
  • the half width ( ⁇ ymax) of the absorption band of the maximum absorption wavelength ( ⁇ ymax) attributed to the side chain y is 40 nm or more from the viewpoint of the effect of the present invention.
  • the maximum absorption wavelength ( ⁇ ymax) attributed to the side chain y is in the range of 280 to 380 nm, and the values of Ro (450) / Ro (550) and Ro (550) / Ro (650) are recorded. This is preferable in the scope of the invention, and the display performance of the organic EL display device can be improved.
  • the compound having a linking group having a linking site in at least three places has an aspect ratio of 1.7 or more, which indicates that the ⁇ / 4 retardation value and the Ro (450 ) / Ro (550) and Ro (550) / Ro (650), which are preferable.
  • the film in the stretching process in which the ⁇ / 4 retardation film is stretched in the direction orthogonal to the transport direction, the film is stretched in the direction orthogonal to the stretching while being stretched within the range of 70 to 95% of the total stretching process. It is preferable that the film is biaxially stretched by the shrinking biaxial stretching process because wrinkles are not easily generated in the stretching process and a retardation film having a high retardation is easily obtained.
  • the film is stretched within a range of 70 to 95% of the total stretching process. It is preferable that the film is biaxially stretched by a biaxial stretching process in which the film is contracted in the direction perpendicular to the stretching direction because wrinkles are not easily generated in the stretching process and a high retardation ⁇ / 4 retardation film is easily obtained.
  • the ratio of the shrinkage ratio with respect to the draw ratio is in the range of 0.3 to 0.6.
  • wrinkles are unlikely to occur, and high retardation ⁇ / 4. It is preferable because a retardation film is easily obtained.
  • the ⁇ / 4 retardation film of the present invention can be suitably provided for a circularly polarizing plate and an organic electroluminescence display device.
  • ⁇ is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
  • the ⁇ / 4 retardation film of the present invention refers to a film having a function of converting linearly polarized light having a specific wavelength into circularly polarized light or converting circularly polarized light into linearly polarized light. Therefore, in the ⁇ / 4 retardation film, the in-plane retardation value Ro is substantially 1 ⁇ 4 with respect to a predetermined wavelength of light (usually in the visible light region).
  • the in-plane retardation value Ro is substantially ⁇ / 4 for a predetermined wavelength of light (usually in the visible light region) when the temperature is 23 ° C. and the relative humidity is 55%.
  • the in-plane retardation value Ro (550) measured at a wavelength of 550 nm is in the range of 120 to 180 nm.
  • the in-plane retardation value Ro is represented by the following general formula (i), and the temperature is 23 ° C./relative
  • the value of the ratio of Ro (450) measured at a wavelength of 450 nm (Ro (450) / Ro (550)) to the in-plane retardation value Ro (550) measured at a wavelength of 550 nm in an environment of 55% humidity is 0.72.
  • the ratio of the in-plane retardation value Ro (550) measured at a wavelength of 550 nm to the in-plane retardation value Ro (650) measured at a wavelength of 650 nm (Ro (550) / Ro (650)) is 0.83 to 0.98 It means within range.
  • the in-plane retardation value Ro (550) measured at a wavelength of 550 nm is more preferably in the range of 120 to 160 nm, and particularly preferably in the range of 130 to 150 nm.
  • the in-plane retardation value Ro is represented by the following formula (i), and the in-plane retardation value measured at a wavelength of 550 nm in an environment of a temperature of 23 ° C. and a relative humidity of 55%.
  • the value of the ratio of Ro (450) (Ro (450) / Ro (550)) measured at a wavelength of 450 nm to Ro (550) is in the range of 0.72 to 0.96, but 0.75 to 0.00. It is preferably in the range of 92, and more preferably in the range of 0.78 to 0.88.
  • the ratio of the in-plane retardation value Ro (550) measured at a wavelength of 550 nm to the in-plane retardation value Ro (650) measured at a wavelength of 650 nm (Ro (550) / Ro (650)) is 0.83. Although it is within the range of ⁇ 0.98, the balance with the Ro (450) / Ro (550) is important, and Ro (450) / Ro (550) is within the range of 0.72 to 0.96. In some cases, Ro (550) / Ro (650) is preferably in the range of 0.83 to 0.98, and Ro (450) / Ro (550) is in the range of 0.75 to 0.92.
  • Ro (550) / Ro (650) is preferably in the range of 0.88 to 0.96, and Ro (450) / Ro (550) is in the range of 0.78 to 0.88. If within range, Ro (550) / Ro (650) is And more preferably .90 in the range of ⁇ 0.94.
  • n x, n y, n z is, 23 ° C., respectively, were measured in an environment of 55% RH, the refractive index at a wavelength of 450 nm, 550 nm, or 650 nm, the surface of the n x the film a maximum refractive index of the inner (refractive index in a slow axis direction), n y is a refractive index in a direction perpendicular to the slow axis in the film plane, n z is the vertical thickness direction in the film plane Where d is the film thickness (nm). Rt represents a retardation value in the thickness direction.
  • the film thickness d is generally within the range of 20 to 100 ⁇ m, preferably within the range of 40 to 80 ⁇ m, and preferably within the range of 40 to 65 ⁇ m. This is particularly preferable from the viewpoint of further manifesting the above effect.
  • the retardation value can be calculated by measuring the birefringence at each wavelength in an environment of 23 ° C. and 55% RH using an Axoscan manufactured by Axometers.
  • a circularly polarizing plate is obtained by laminating so that the angle between the in-plane slow axis of the ⁇ / 4 retardation film and the transmission axis of the polarizer described later is substantially 45 °.
  • substantially 45 ° means within a range of 45 ⁇ 5 °.
  • the angle between the in-plane slow axis of the ⁇ / 4 retardation film of the present invention and the transmission axis of the polarizer is preferably in the range of 41 to 49 °, and in the range of 42 to 48 °. More preferably, it is more preferably in the range of 43 to 47 °, and most preferably in the range of 44 to 46 °.
  • Optical performance modifier In the ⁇ / 4 retardation film of the present invention, when the in-plane retardation value at the measurement wavelength ⁇ (nm) is expressed as Ro ( ⁇ ) in an environment defined by the present invention at a temperature of 23 ° C. and a relative humidity of 55%. , Ro (450) / Ro (550) is in the range of 0.72 to 0.96, and Ro (550) / Ro (650) is in the range of 0.83 to 0.98.
  • the ⁇ / 4 retardation film contains a compound bonded with a linking group having a linking site in at least three positions, and is the longest among the groups bonded through the linking group
  • the half-value width ( ⁇ ymax) of the maximum absorption wavelength ( ⁇ ymax) attributed to the side chain y is the half-value width ( ⁇ xmax) of the absorption band of the maximum absorption wavelength ( ⁇ xmax) attributed to the main chain x
  • the wavelength dispersion of the propagation speed of light in the side chain direction can be made higher than in the main chain direction.
  • the forward wavelength dispersion of the refractive index in the side chain direction can be increased.
  • the reverse wavelength dispersion of the in-plane retardation value Ro can be set to a desired value.
  • main chain x and the side chain y in the compound bonded with a linking group having a linking site in at least three places are defined as follows.
  • a chemical structure portion constituted by an interatomic distance between atoms having the longest linear distance via a linking group is defined as a main chain x, and branched to the main chain x via a linking group
  • the chemical structure portion is defined as side chain y.
  • a retardation film having an in-plane retardation value of about 50 nm used in a liquid crystal television can achieve a desired wavelength dispersion characteristic even when the half-value width ( ⁇ ymax) is less than 40 nm.
  • the half width ( ⁇ ymax) of the absorption band of the maximum absorption wavelength ( ⁇ ymax) attributed to the side chain y is preferably 40 nm or more.
  • the absorption waveform attributed to the main chain x and the side chain y of the compound I can be measured using a spectrophotometer (UV-2450, manufactured by Shimadzu Corporation).
  • a polarizer that does not absorb ultraviolet light (Grand Taylor prism, manufactured by Kogyo Giken) was placed between the sample and the light source, and a solution dissolved in tetrahydrofuran at a concentration of 10 ⁇ 4 mol / L was placed in a quartz cell. Measure the absorbance of the sample.
  • the absorbance in the state where the transmission axis of the polarizer and the stretching direction of the film are matched and the absorbance in the state where the direction orthogonal to the stretching direction is matched are measured.
  • the absorption waveform having higher absorbance in the state in which the stretching direction of the film is matched is a waveform belonging to the main chain x of the optical performance modifier.
  • the absorption waveform having higher absorbance in the state aligned with the direction orthogonal to the film stretching direction is a waveform belonging to the side chain y of the optical performance modifier.
  • the half width ( ⁇ ymax) and half width ( ⁇ ymax) in this case refer to the half width of the absorption waveform obtained by the above measurement belonging to the main chain x and the side chain y.
  • the half width of the absorption waveform is described in, for example, “The Fourth Edition Experimental Chemistry Lecture 3 Basic Operation III” (Maruzen 1991), page 154, edited by the Japanese Society of Science.
  • the half-value width is explained with an example in which the horizontal axis is taken on the wave number scale, but the half-value width in the present invention is the value when the axis is taken on the wavelength scale,
  • the unit is nm. Specifically, it represents the width of the absorption band that is 1 ⁇ 2 of the absorbance at the maximum absorption wavelength.
  • the maximum absorption wavelength ( ⁇ ymax) attributed to the side chain y is preferably in the range of 280 to 380 nm.
  • the maximum absorption wavelength is in this range, the ⁇ / 4 retardation film is not colored and good wavelength dispersion characteristics can be obtained within the range of 400 to 700 nm.
  • the aspect ratio of the compound having a chemical structure in which the side chain y is bonded to the linear main chain x is preferably 1.7 or more. Increasing the aspect ratio is preferable for achieving both the ⁇ / 4 retardation value and the values of Ro (450) / Ro (550) and Ro (550) / Ro (650) described in this case.
  • the aspect ratio of the compound is a value calculated using Winstar MOPAC AM1 (MOP6W70) (Senda, Development of Molecular Computation Support System, Idemitsu Technical Report, 49.1, pages 106 to 111 (2006)).
  • the aspect ratio is the molecular length / molecular width
  • the molecular length is a value obtained by adding the van der Waals radii of two atoms at both ends to the maximum interatomic distance in the compound
  • the molecular width is This is a value obtained by adding the van der Waals radii of two atoms at both ends to the maximum interatomic distance when each atom is projected onto a plane perpendicular to the molecular long axis.
  • the compound (compound I) having the above-mentioned wavelength dispersion characteristic and having a chemical structure according to the present invention is preferably selected from compounds represented by the following general formula (A).
  • L 1 and L 2 each independently represent a single bond or a divalent linking group.
  • R 1 , R 2 and R 3 each independently represent a substituent.
  • n represents an integer of 0 to 2.
  • Wa and Wb each represent a hydrogen atom or a substituent, and at least one of Wa and Wb has a heterocyclic structure.
  • L 1 and L 2 each independently represent a single bond or a divalent linking group, and L 1 and L 2 are preferably O, COO, and OCO. More preferred is OCO (carbonyloxy group).
  • R 1 , R 2 and R 3 each independently represent a substituent.
  • substituent represented by R 1 , R 2 and R 3 include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), alkyl group (methyl group, ethyl group, n-propyl group).
  • Etc. mercapto group, alkylthio group (methylthio group, ethylthio group, n-hexadecylthio group, etc.), arylthio group (phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group, etc.), sulfamoyl group (N-ethylsulfide group, etc.) Famoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N'-phenylcarbamoyl) ) Sulfamoi Group), sulfo group, acyl group (acetyl group, pivaloylbenzoyl group, etc.), carbamoy
  • R 1 and R 2 are preferably a substituted or unsubstituted benzene ring or a substituted or unsubstituted cyclohexane ring. More preferably, it is a benzene ring having a substituent or a cyclohexane ring having a substituent, and the benzene ring having a substituent at the 4-position is represented by the general formula (A) in the slow axis direction of the ⁇ / 4 retardation film. This is particularly preferable from the viewpoint of orienting the main chain of the compound and increasing the refractive index nx in the slow axis direction.
  • R 3 is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a hydroxy group, a carboxy group, an alkoxy group, an aryloxy group, an acyloxy group, a cyano group, or an amino group. More preferably, they are a hydrogen atom, a halogen atom, an alkyl group, a cyano group, or an alkoxy group. More preferably, it is a hydrogen atom.
  • Wa and Wb each independently represent a hydrogen atom or a substituent, and at least one of Wa and Wb has a heterocyclic structure.
  • heterocyclic group represented by Wa and Wb examples include 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group, 2-benzimidazolyl group, 2-pyridinonyl group and the like. be able to.
  • heterocyclic group can have a condensed ring structure condensed with a benzene ring or the like.
  • Wa and Wb are groups corresponding to the side chain according to the present invention, and it is preferable that the side chain has a high refractive index atom.
  • the high refractive index atom means a sulfur atom, a nitrogen atom, or a phosphorus atom
  • the side chain preferably contains 1 to 4 high refractive index molecules, more preferably 2 pieces. .
  • the wavelength dispersion characteristic can be improved.
  • the synthesis of the compound represented by the general formula (A) can be performed by applying a known synthesis method. Specifically, it can be synthesized with reference to the methods described in Journal of Chemical Crystallography (1997); 27 (9); 512-526, JP 2010-31223 A, JP 2008-107767 A, and the like. .
  • Examples of such compound I include the following compounds.
  • These compounds are preferably contained in the range of 1 to 15% by mass with respect to cellulose acylate. More preferably, it is in the range of 2 to 10% by mass.
  • the matrix resin is preferably composed of a thermoplastic resin, and more preferably, the main component is cellulose acylate.
  • the “main component” in the present invention means that 70% by mass or more of the thermoplastic resin component constituting the ⁇ / 4 retardation film is composed of cellulose acylate.
  • the average acyl group substitution degree is preferably in the range of 2.00 to 3.00, more preferably in the range of 2.20 to 2.80, and still more preferably. Is in the range of 2.40 to 2.70.
  • the average degree of acyl group substitution here refers to the average value of the number of esterified hydroxy groups among the three hydroxy groups of each anhydroglucose constituting cellulose, and ranges from 0 to 3.00. Takes the value in.
  • the portion not substituted with an acyl group is usually present as a hydroxy group.
  • These cellulose acylates can be synthesized by a known method.
  • the acyl group substitution degree is a value determined according to the method prescribed in ASTM-D817-96 (testing method for cellulose acylate, etc.).
  • the number average molecular weight (Mn) of the cellulose acylate according to the present invention is preferably in the range of 30,000 to 300,000 from the viewpoint of increasing the mechanical strength of the obtained ⁇ / 4 retardation film. Furthermore, those in the range of 50,000 to 200,000 are preferably used.
  • the ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the cellulose acylate is preferably in the range of 1.4 to 3.0.
  • the weight average molecular weight Mw and number average molecular weight Mn of the cellulose acylate can be measured using gel permeation chromatography (GPC).
  • Solvent Methylene chloride Column: Shodex K806, K805, K803G (Used by connecting three columns manufactured by Showa Denko KK) Column temperature: 25 ° C Sample concentration: 0.1% by mass Detector: RI Model 504 (GL Science Co., Ltd.) Pump: L6000 (manufactured by Hitachi, Ltd.) Flow rate: 1.0 ml / min Calibration curve: A calibration curve using 13 samples of standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) and having an Mw in the range of 1,000,000 to 500 was used. Thirteen samples are used at approximately equal intervals.
  • thermoplastic resin other than cellulose acylate may be used.
  • thermoplastic resin refers to a resin that has the characteristics that it becomes soft when heated to the glass transition temperature or melting point and can be molded into the desired shape.
  • thermoplastic resin for example, polyethylene (PE), high density polyethylene, medium density polyethylene, low density polyethylene, polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene chloride, polystyrene ( PS), polyvinyl acetate (PVAc), Teflon (registered trademark) (polytetrafluoroethylene, PTFE), ABS resin (acrylonitrile butadiene styrene resin), AS resin (acrylonitrile styrene resin), acrylic resin (PMMA, etc.), etc. are used. be able to.
  • PE polyethylene
  • PVC polyvinyl chloride
  • PS polyvinylidene chloride
  • PS polystyrene
  • PVAc polyvinyl acetate
  • Teflon registered trademark
  • ABS resin acrylonitrile butadiene styrene resin
  • AS resin acrylonitrile styrene resin
  • acrylic resin PMMA, etc.
  • PA polyamide
  • nylon polyacetal
  • PC polycarbonate
  • m-PPE modified polyphenylene ether
  • PBT polybutylene terephthalate
  • PET polyethylene terephthalate
  • GF-PET glass fiber reinforced polyethylene terephthalate
  • COP cyclic polyolefin
  • polyphenylene sulfide PPS
  • polytetrafluoroethylene PTFE
  • polysulfone polyethersulfone
  • amorphous polyarylate liquid crystal polymer
  • Polyetheretherketone thermoplastic polyimide (PI)
  • PAI polyamideimide
  • thermoplastic resin in accordance with the application of the present invention.
  • Organic solvents useful for preparing cellulose acylate solution or dope by dissolving cellulose acylate mainly include chlorinated organic solvents and non-chlorinated organic solvents.
  • Examples of the chlorinated organic solvent include methylene chloride (methylene chloride).
  • methylene chloride methylene chloride
  • non-chlorine organic solvents include methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1, Examples include 1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, and nitroethane.
  • a dissolution method at normal temperature can be used, but a known dissolution method such as a high-temperature dissolution method, a cooling dissolution method, or a high-pressure dissolution method should be used. However, it is preferable from the viewpoint of reducing insoluble matter.
  • methylene chloride can be used, but methyl acetate, ethyl acetate, and acetone are preferably used, and among them, methyl acetate is particularly preferable.
  • an organic solvent having good solubility in the cellulose acylate is referred to as a good solvent, and has a main effect on dissolution, and an organic solvent used in a large amount among them is a main (organic) solvent or It is called the main (organic) solvent.
  • the dope used for forming the ⁇ / 4 retardation film of the present invention preferably contains an alcohol having 1 to 4 carbon atoms in the range of 1 to 40% by mass in addition to the organic solvent. .
  • These alcohols after casting the dope on a metal support, start to evaporate the organic solvent, and when the relative proportion of the alcohol component increases, the dope film (web) gels, making the web strong and supporting the metal It can act as a gelling solvent that makes it easy to peel off from the body.
  • the proportion of these alcohols is low, it also has a role of promoting dissolution of cellulose acylate, a non-chlorine organic solvent.
  • Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Of these, it is preferable to use ethanol from the viewpoints of excellent dope stability, relatively low boiling point, and good drying properties. These alcohols are categorized as poor solvents because they are not soluble in cellulose acylate alone.
  • the cellulose acylate concentration in the dope is preferably in the range of 15 to 30% by mass, and the dope viscosity is preferably adjusted in the range of 100 to 500 Pa ⁇ s from the viewpoint of obtaining excellent film surface quality. .
  • additives examples include plasticizers, ultraviolet absorbers, antioxidants, deterioration inhibitors, peeling aids, surfactants, dyes, and fine particles.
  • additives other than fine particles may be added when preparing the cellulose acylate solution, or may be added when preparing the fine particle dispersion. It is preferable to add a plasticizer, an antioxidant, an ultraviolet absorber, or the like that imparts heat and moisture resistance to the polarizing plate used in the display device.
  • the ⁇ / 4 retardation film of the present invention preferably contains a plasticizer.
  • the ⁇ / 4 retardation film of the present invention preferably contains a polyester plasticizer having a number average molecular weight (Mn) in the range of 1000 to 10,000.
  • the specific structure of the polyester plasticizer is not particularly limited, and a polyester plasticizer having an aromatic ring or a cycloalkyl ring in the molecule can be used.
  • polyester plasticizer examples include a polyester plasticizer represented by the following general formula (a).
  • B represents a benzene monocarboxylic acid group or an aliphatic monocarboxylic acid group
  • G represents an alkylene glycol group having 2 to 12 carbon atoms, an aryl glycol group having 06 to 12 carbon atoms, or 4 carbon atoms.
  • A represents an alkylene dicarboxylic acid group having 4 to 12 carbon atoms or an aryl dicarboxylic acid group having 6 to 12 carbon atoms
  • n represents an integer of 1 or more.
  • the polyester plasticizer represented by the general formula (a) is obtained by the same reaction as a normal polyester plasticizer.
  • benzene monocarboxylic acid component of the polyester plasticizer examples include benzoic acid, paratertiary butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, normal propylbenzoic acid, and aminobenzoic acid. , Acetoxybenzoic acid and the like, each of which can be used alone or as a mixture of two or more.
  • the aliphatic monocarboxylic acid component of the polyester plasticizer is preferably an aliphatic monocarboxylic acid having 3 or less carbon atoms, more preferably acetic acid, propionic acid or butanoic acid, and most preferably acetic acid.
  • the number of carbon atoms of the monocarboxylic acids used at both ends of the polycondensed ester is 3 or less, the heat loss of the compound does not increase, and no surface failure occurs.
  • a monocarboxylic acid having a cycloaliphatic having 3 to 8 carbon atoms is preferred, a monocarboxylic acid having a cycloaliphatic having 6 carbons is more preferred, and cyclohexanecarboxylic acid and 4-methyl-cyclohexanecarboxylic acid are most preferred.
  • the cycloaliphatic carbon number of the monocarboxylic acid used at both ends of the polycondensed ester is in the range of 3 to 8, the heat loss of the compound does not increase, and it is preferable in that a surface failure does not occur.
  • alkylene glycol component having 2 to 12 carbon atoms of the polyester plasticizer examples include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, and 1,3-butanediol.
  • an alkylene glycol having 2 to 12 carbon atoms is particularly preferable in terms of excellent compatibility with cellulose acylate, more preferably an alkylene glycol having 2 to 6 carbon atoms, and further preferably a carbon number. Is an alkylene glycol of 2 to 4.
  • Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the polyester plasticizer include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. It can be used alone or as a mixture of two or more.
  • alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the polyester plasticizer examples include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and the like. Each of these may be used alone or as a mixture of two or more.
  • examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and the like.
  • the number average molecular weight of the polyester plasticizer preferably used for the ⁇ / 4 retardation film of the present invention is in the range of 200 to 10,000, more preferably in the range of 300 to 3000.
  • the acid value of the polyester plasticizer is preferably 0.5 mgKOH / g or less, more preferably 0.3 mgKOH / g or less.
  • the hydroxy value of the polyester plasticizer is preferably 25 mgKOH / g or less, and more preferably 15 mgKOH / g or less.
  • an acid value means the milligram number of potassium hydroxide required in order to neutralize the acid (carboxy group which exists in a sample) contained in 1g of samples. The acid value is measured according to JIS K0070.
  • plasticizers may be applied to the ⁇ / 4 retardation film of the present invention.
  • plasticizers examples include polyhydric alcohol ester plasticizers, glycolate plasticizers, phthalate ester plasticizers, citrate ester plasticizers, fatty acid ester plasticizers, and phosphate esters.
  • plasticizers examples include polyhydric alcohol ester plasticizers, glycolate plasticizers, phthalate ester plasticizers, citrate ester plasticizers, fatty acid ester plasticizers, and phosphate esters.
  • plasticizers examples include polyhydric alcohol ester plasticizers, glycolate plasticizers, phthalate ester plasticizers, citrate ester plasticizers, fatty acid ester plasticizers, and phosphate esters.
  • plasticizer examples include a plasticizer, a polycarboxylic acid ester plasticizer, and an acrylic plasticizer.
  • the ⁇ / 4 retardation film of the present invention comprises cellulose having at least one pyranose structure or furanose structure in the range of 1 to 12, and all or part of the hydroxy groups of the structure are esterified It is preferable to include an ester compound excluding the ester.
  • ester compounds excluding cellulose esters having such a structure are collectively referred to as “sugar ester compounds”.
  • sugar ester compounds examples include the following, but the present invention is not limited to these.
  • Examples of the compound (saccharide) having a pyranose structure or furanose structure include glucose, galactose, mannose, fructose, xylose, or arabinose, lactose, sucrose, nystose, 1F-fructosylnystose, stachyose, maltitol, lactitol, lactulose , Cellobiose, maltose, cellotriose, maltotriose, raffinose, and kestose.
  • gentiobiose gentiotriose
  • gentiotetraose gentiotetraose
  • xylotriose galactosyl sucrose
  • sucrose kestose, nystose, 1F-fructosyl nystose, stachyose and the like are preferable, and sucrose is more preferable.
  • the monocarboxylic acid used for esterifying all or part of the hydroxy group of the above-mentioned compound (sugar) having a pyranose structure or furanose structure for the purpose of constituting a sugar ester compound is not particularly limited and is known. Aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid and the like can be used. The carboxylic acid used may be one kind alone or a mixture of two or more kinds.
  • Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid , Saturated fatty acids such as tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid; Examples thereof include unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and o
  • Examples of preferable alicyclic monocarboxylic acids include acetic acid, cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.
  • aromatic monocarboxylic acids examples include aromatic monocarboxylic acids having an alkyl group or alkoxy group introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, cinnamic acid, benzylic acid, biphenylcarboxylic acid, and naphthalene.
  • aromatic monocarboxylic acids having two or more benzene rings such as carboxylic acid and tetralincarboxylic acid, or derivatives thereof.
  • the sugar ester compound described above is based on 100% by mass of the ⁇ / 4 retardation film. It is preferably contained within the range of 1 to 30% by mass, and more preferably within the range of 5 to 30% by mass. Within this range, the above-described excellent effects are exhibited, and there is no bleed out and the like.
  • the ⁇ / 4 retardation film of the present invention or the protective film constituting the circularly polarizing plate described later preferably contains an ultraviolet absorber.
  • Examples of the ultraviolet absorber used include benzotriazole-based, 2-hydroxybenzophenone-based or salicylic acid phenyl ester-based ones.
  • 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3 Triazoles such as 5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone And benzophenones.
  • UV absorbers with a molecular weight of 400 or more are less likely to volatilize at high boiling points and are difficult to disperse even during high temperature molding, so that light resistance is effectively improved with a relatively small amount of addition. Can do.
  • Examples of the ultraviolet absorber having a molecular weight of 400 or more include 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2-benzotriazole, 2,2-methylenebis [4- ( Benzotriazoles such as 1,1,3,3-tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol], bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, Hindered amines such as bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and further 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butyl Bis (1,2,2,6,6-pentamethyl-4-piperidyl) malonate, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy Cis] ethyl] -4- [3- (3
  • 2- [2-hydroxy-3,5-bis ( ⁇ , ⁇ -dimethylbenzyl) phenyl] -2-benzotriazole and 2,2-methylenebis [4- (1,1,3,3- Tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol] is particularly preferred.
  • UV absorbers commercially available products may be used.
  • TINUBIN 109, TINUVIN 171, TINUVIN 234, TINUVIN 326, TINUVIN 327, TINUVIN 328, TINUVIN 928, etc. manufactured by BASF Japan Ltd. are absorbed.
  • An agent can be preferably used.
  • antioxidants can also be added to the ⁇ / 4 retardation film in order to improve the thermal decomposability and thermal colorability during molding.
  • an antistatic agent can be added to impart antistatic performance to the ⁇ / 4 retardation film.
  • ⁇ Phosphorus flame retardant For the ⁇ / 4 retardation film of the present invention, a flame retardant acrylic resin composition containing a phosphorus flame retardant may be used.
  • Phosphorus flame retardants used here include red phosphorus, triaryl phosphate ester, diaryl phosphate ester, monoaryl phosphate ester, aryl phosphonate compound, aryl phosphine oxide compound, condensed aryl phosphate ester, halogenated alkyl phosphorus. Examples thereof include one or a mixture of two or more selected from acid esters, halogen-containing condensed phosphates, halogen-containing condensed phosphonates, halogen-containing phosphites, and the like.
  • triphenyl phosphate 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phenylphosphonic acid, tris ( ⁇ -chloroethyl) phosphate, tris (dichloropropyl) Examples thereof include phosphate and tris (tribromoneopentyl) phosphate.
  • the ⁇ / 4 retardation film of the present invention has, for example, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, and hydrated silica to improve handling. It is preferable to contain a matting agent such as inorganic fine particles such as calcium acid, aluminum silicate, magnesium silicate, and calcium phosphate, and a crosslinked polymer. Among these, silicon dioxide is preferably used because it can reduce the increase in haze of the film.
  • the primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm.
  • the ⁇ / 4 retardation film of the present invention can be formed according to a known method. Hereinafter, typical solution casting methods and melt casting methods will be described.
  • the ⁇ / 4 retardation film of the present invention can be produced by a solution casting method.
  • the process of drying the cast dope as a web the process of peeling from the metal support, the process of stretching or shrinking the peeled web, the process of drying, the process of winding up the finished film, etc. .
  • the concentration of cellulose acylate in the dope is preferably higher because the drying load after casting on a metal support can be reduced, but if the concentration of cellulose acylate is too high, the load during filtration increases. Filtration accuracy deteriorates.
  • the concentration that achieves both of these is preferably in the range of 10 to 35% by mass, and more preferably in the range of 15 to 25% by mass.
  • the metal support in the casting (casting) step preferably has a mirror-finished surface, and as the metal support, a stainless steel belt or a drum whose surface is plated with a casting is preferably used.
  • the cast width is preferably in the range of 1 to 4 m.
  • the surface temperature of the metal support in the casting step is appropriately selected and set within a range from ⁇ 50 ° C. to a temperature below which the solvent does not boil and foam. A higher temperature is preferable because the web can be dried faster, but if it is too high, the web may foam and flatness may deteriorate.
  • a preferable support temperature is appropriately determined within a range of 0 to 100 ° C., and a temperature range of 5 to 30 ° C. is more preferable.
  • the method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing warm air or cold air, and a method of bringing hot water into contact with the back side of the metal support. The method using hot water is preferable because the heat transfer is performed efficiently, and the time until the temperature of the metal support becomes constant is short.
  • the amount of residual solvent when peeling the web from the metal support is preferably set in the range of 10 to 150% by mass, more preferably 20%. It is in the range of ⁇ 40 mass% or 60 to 130 mass%, particularly preferably in the range of 20 to 30 mass% or 70 to 120 mass%.
  • the amount of residual solvent as used in the present invention is defined by the following formula.
  • Residual solvent amount (% by mass) ⁇ (MN) / N ⁇ ⁇ 100
  • M is the mass of a sample taken during or after production of the web or film
  • N is the mass after heating M at 115 ° C. for 1 hour.
  • the web is peeled off from the metal support, and further dried, so that the residual solvent amount is preferably 1.0% by mass or less, more preferably 0 to 0.00.
  • the range is 01% by mass.
  • a roller drying method for example, a method in which webs are alternately passed through a number of upper and lower rollers and a method in which the web is dried while being conveyed by a tenter method is employed.
  • the in-plane retardation Ro550 measured at a wavelength of 550 nm is preferably in the range of 120 to 180 nm.
  • the retardation can be imparted by film stretching.
  • the ⁇ / 4 retardation film of the present invention may be referred to as a cellulose acylate film.
  • the stretching method For example, a method in which a circumferential speed difference is applied to a plurality of rollers, and the roller is stretched in the longitudinal direction using the circumferential speed difference between the rollers. Both ends of the web are fixed with clips and pins, and the interval between the clips and pins is widened in the traveling direction. And a method of stretching in the vertical direction, a method of stretching in the horizontal direction and stretching in the horizontal direction, a method of stretching in the vertical and horizontal directions and stretching in both the vertical and horizontal directions, and the like. Of course, these methods may be used in combination.
  • the film may be stretched in the transverse direction, longitudinally, or in both directions with respect to the film forming direction, and when stretched in both directions, simultaneous stretching or sequential stretching may be used. May be.
  • driving the clip portion by the linear drive method is preferable because smooth stretching can be performed and the risk of breakage and the like can be reduced.
  • the film is stretched in the direction in which the slow axis is to be generated and contracted in the vertical direction (fast axis direction), and the ratio of the shrinkage rate to the stretching ratio is controlled.
  • the orientation direction of the principal axis of the compound represented by the general formula (A) is adjusted so that the orientation direction (principal chain direction) of the principal axis of compound I matches the principal axis direction (stretching direction) of cellulose acylate. Control is the preferred method.
  • FIGS. 1A and 1B are schematic diagrams illustrating the orientation of cellulose acylate and compound I.
  • FIG. 1A and 1B are schematic diagrams illustrating the orientation of cellulose acylate and compound I.
  • the main chain 1-1 of the matrix resin eg, cellulose ester resin
  • the side chain (side) used as an additive is used.
  • Compound (compound I) 1-3 having a chemical structure in which side chain y is bonded to linear main chain x having chain y) 1-5 has main chain (linear main chain x) 1-4 and side chain ( The average direction 1-6 of the side chain y) 1-5 is oriented in the stretching direction 1-2.
  • the main chain 1-4 / side chain 1-5 constituting the compound 3 having the chemical structure in which the side chain y is bonded to the linear main chain x is displaced in the direction from the main chain 1-1 of the matrix resin. Therefore, sufficient phase difference effect is not exhibited.
  • the retardation Rt in the thickness direction becomes high.
  • the orientation of the compound 1-3 deviated from the main chain 1-1 of the matrix resin is contracted 1-7 in the direction perpendicular to the stretching direction (fast axis direction) in the stretching step.
  • the orientation direction of the main chain of the compound 1-3 can be rotated 1-8. In this way, when the orientation direction of the main axis 1-4 of the compound 1-3 is aligned with the orientation direction of the main chain 1-1 of the matrix resin, the retardation value can be increased. .
  • the value of the ratio of shrinkage ratio to the stretching ratio is preferably in the range of 0.3 to 0.6, but is preferably in the range of 0.40 to 0.50.
  • the main axis can be aligned with the main chain of the matrix resin, and the side chain of Compound I can also be oriented in the film fast axis direction.
  • the stretching step a method of starting shrinkage after stretching within the range of 70 to 95% of the total stretching step is preferable.
  • the draw ratio is R
  • the draw ratio is 0.70 ⁇ (R ⁇ 1.00) +1.00 to 0.95 ⁇ (R ⁇ 1) in the range of 70 to 95% of the entire draw process. .00) +1.00.
  • the film in the step of stretching the ⁇ / 4 retardation film at a stretching ratio R in the direction orthogonal to the transport direction, the film is contracted in the direction orthogonal to the stretching while being stretched within the range of 70 to 95% of the total stretching step. It is preferable that it is biaxially stretched by the axial stretching step. For example, when the draw ratio R is 2.00 times, the film is stretched within the range of 70 to 95% of the entire stretching process, in other words, the film is stretched within the range of the stretch ratio of 1.70 to 1.95 times. It is preferable that the film is biaxially stretched by a biaxial stretching process in which the film is contracted in the direction perpendicular to the stretching direction.
  • the ⁇ / 4 retardation film is stretched within a range of 70 to 95% of the total stretching step in the step of stretching at a stretching ratio R in the direction of an angle of greater than 0 ° and 90 ° or less with respect to the transport direction. It is preferable that the film is biaxially stretched by a biaxial stretching process in which the film is contracted in the direction perpendicular to the stretching.
  • the stretching process usually involves stretching in the width direction (TD direction) and contracting in the transport direction (MD direction), but when contracting, it is easy to match the main chain direction when transported in an oblique direction. In addition, the phase difference effect is even greater.
  • the shrinkage rate is determined by the transport angle.
  • FIG. 2 is a schematic diagram for explaining the shrinkage ratio in oblique stretching.
  • shrinkage rate M 2 / M 1 It is represented by
  • 1-11 represents the stretching direction (TD direction)
  • 1-13 represents the transport direction (MD direction)
  • 1-14 represents the slow axis.
  • the slow axis of the ⁇ / 4 retardation film is preferably within a range of 30 to 60 ° with respect to the transport direction. It is preferable to be in the range of 50%.
  • the ⁇ / 4 retardation film of the present invention has an orientation angle of 45 ° ⁇ 2 ° with respect to the transport direction, and can be bonded between rolls with a polarizing film. preferable.
  • an obliquely stretched tenter as a method for imparting an oblique orientation to the cellulose acylate film to be stretched.
  • the orientation angle of the film can be set freely by changing the rail pattern in various ways, and the film orientation axis can be set to the left and right in the film width direction with high accuracy. It is preferable that the film stretching apparatus be capable of being oriented to the film and controlling the film thickness and retardation with high accuracy.
  • FIG. 3 is a schematic view showing an example of a rail pattern of an oblique stretching machine applicable to the production of the ⁇ / 4 retardation film of the present invention.
  • the figure shown here is an example, Comprising: This invention is not limited to this.
  • the feeding direction D1 of the long film original is different from the winding direction D2 of the stretched film after stretching, and forms a feeding angle ⁇ i.
  • the feeding angle ⁇ i can be arbitrarily set to a desired angle in the range of more than 0 ° and less than 90 °.
  • the long film fabric is gripped at both ends by the left and right grippers (tenters) at the entrance 1 of the oblique stretching machine (position A in FIG. 3), and travels as the grippers travel.
  • the left and right gripping tools are the left and right gripping tools Ci and Co, which are opposed to the oblique stretcher entrance 1 (position A in FIG. 3) in a direction substantially perpendicular to the film traveling direction (feeding direction D1). Then, the film travels on the left and right asymmetric rails Ri and Ro, and the film held by the tenter is released at the position at the end of stretching (position B in FIG. 3).
  • the gripping tools Ci and Co that are opposed in the direction substantially perpendicular to the film feeding direction D1 are In the state of position B, the straight line connecting the grippers Ci and Co is inclined by an angle ⁇ L with respect to a direction substantially perpendicular to the film winding direction D2.
  • the original film is stretched obliquely in the direction of ⁇ L.
  • substantially vertical indicates that the angle is in a range of 90 ⁇ 1 °.
  • This tenter is a device that heats the film fabric to an arbitrary temperature at which it can be stretched and stretches it obliquely.
  • This tenter includes a heating zone, a pair of rails on the left and right on which a gripping tool for transporting the film travels, and a number of gripping tools that travel on the rails. Both ends of the film sequentially supplied to the entrance portion of the tenter are gripped by a gripping tool, the film is guided into the heating zone, and the film is released from the gripping tool at the exit portion of the tenter. The film released from the gripping tool is wound around the core.
  • Each of the pair of rails has an endless continuous track, and the gripping tool which has released the grip of the film at the exit portion of the tenter travels outside and is sequentially returned to the entrance portion.
  • the rail pattern of the tenter has an asymmetric shape on the left and right, so that the rail pattern can be adjusted manually or automatically according to the orientation angle ⁇ , the draw ratio, etc. given to the long stretched film to be manufactured. It has become.
  • the position of each rail part and the rail connecting part can be freely set and the rail pattern can be arbitrarily changed (in FIG. 3).
  • (Circle) is an example of a connection part.).
  • the gripping tool of the tenter may run at a constant speed with a constant distance from the front and rear gripping tools, or the speed may be changed to perform a contraction process.
  • the traveling speed of the gripping tool can be selected as appropriate, but is usually 1 to 100 m / min.
  • the difference in travel speed between the pair of left and right grippers is usually 1% or less, preferably 0.5% or less, more preferably 0.1% or less of the travel speed. This is because if there is a difference in the traveling speed between the left and right sides of the film at the exit of the stretching process, wrinkles and shifts at the exit of the stretching process will occur. Because. In general tenter devices, etc., there are speed irregularities that occur in the order of seconds or less depending on the period of the sprocket teeth that drive the chain, the frequency of the drive motor, etc. This does not correspond to the speed difference described in the embodiment of the invention.
  • a rail that regulates the trajectory of the gripping tool is often required to have a high bending rate, particularly in a portion where the film is transported obliquely.
  • the long film original fabric is gripped by the right and left gripping tools at the oblique stretching machine entrance 1 (position A in FIG. 3) in sequence, and travels as the gripping tool travels.
  • the right and left gripping tools facing the direction substantially perpendicular to the film traveling direction (feeding direction) D1 at the oblique stretching machine inlet 2 (position E in FIG. 3) run on the left-right asymmetric rail, It passes through a heating zone having a preheating zone, a stretching zone, and a heat setting zone.
  • the preheating zone refers to a section where the distance between the gripping tools gripping both ends is kept constant at the heating zone entrance.
  • the stretching zone refers to the interval until the gap between the gripping tools that grips both ends starts to reach a predetermined interval.
  • the oblique stretching as described above is performed, but the stretching may be performed in the longitudinal direction or the transverse direction before and after the oblique stretching as necessary.
  • the orientation of the optical adjusting agent (for example, the compound I) deviated from the main chain of cellulose acylate which is a matrix resin by performing a shrinkage treatment after the stretching treatment. Is contracted in a direction perpendicular to the stretching direction (fast axis direction) to rotate the orientation state of the optical adjusting agent, and the main axis of the optical adjusting compound is aligned with the main chain of cellulose acylate which is a matrix resin.
  • the slope of ny-order chromatic dispersion in the visible light region can be made steep.
  • the heat setting zone refers to the section in which the gripping tools at both ends run parallel to each other during the period when the spacing between the gripping tools after the stretching zone becomes constant again.
  • the heat setting zone After passing through the heat setting zone, it may pass through a section (cooling zone) where the temperature in the zone is set to the glass transition temperature Tg ° C. or lower of the thermoplastic resin constituting the film.
  • a rail pattern that narrows the gap between the opposing grippers in advance may be used.
  • the temperature of each zone is the glass transition temperature Tg of the thermoplastic resin
  • the temperature of the preheating zone is within the range of Tg to Tg + 30 ° C
  • the temperature of the stretching zone is within the range of Tg to Tg + 30 ° C
  • the temperature of the cooling zone is It is preferable to set within the range of Tg-30 to Tg ° C.
  • a temperature difference may be given in the width direction in the stretching zone.
  • a method of adjusting the opening degree of the nozzle for sending warm air into the temperature-controlled room so as to make a difference in the width direction, and controlling heating by arranging heaters in the width direction are known. Can be used.
  • the length of the preheating zone, the stretching zone, the shrinking zone and the cooling zone can be appropriately selected. The length of the preheating zone is usually within a range of 100 to 150% of the length of the stretching zone, and the length of the fixed zone Is usually in the range of 50 to 100%.
  • the stretching ratio in the stretching step is the value of the ratio of the distance between the pair of grips at the stretching start position when the pair of grippers moves to the stretching end position.
  • the draw ratio R is preferably in the range of 1.3 to 3.0, more preferably in the range of 1.5 to 2.8. When the draw ratio is within this range, thickness unevenness in the width direction is reduced, which is preferable. In the stretching zone of the oblique stretching tenter, if the stretching temperature is differentiated in the width direction, the thickness unevenness in the width direction can be further improved.
  • the stretching methods shown in FIGS. 4A, 4B, 4C, 5A and 5B can be exemplified.
  • 4A, 4B, and 4C are schematic diagrams illustrating an example of a manufacturing method according to an embodiment of the present invention (an example in which the film is drawn from a long film original fabric roll and then obliquely stretched).
  • 5A and 5B are schematic views illustrating another example of the manufacturing method according to the embodiment of the present invention (an example in which a long film original is continuously stretched obliquely without being wound).
  • FIG. 4A, FIG. 4B and FIG. 4C show a pattern in which a long film original fabric once wound up in a roll is drawn out and obliquely stretched.
  • 5A and 5B show a pattern in which an oblique stretching process is continuously performed without winding a long film original.
  • a film feeding device 16 In each figure, a film feeding device 16, a transport direction changing device 17, a winding device 18, and a film forming device 19 are shown.
  • the film feeding device 16 is slidable and pivotable so that the film can be fed at a predetermined angle with respect to the obliquely stretched tenter inlet, or the film feeding device 16 is slidable, and the transport direction changing device It is preferable that the film can be sent out to the entrance of the obliquely stretched tenter by 17.
  • the film feeding device 16 and the conveyance direction changing device 17 By configuring the film feeding device 16 and the conveyance direction changing device 17 in such a configuration, the width of the entire manufacturing apparatus can be further reduced, and the film feeding position and angle can be finely controlled. This makes it possible to obtain a long stretched film with small variations in film thickness and optical value.
  • the film feeding device 16 and the transport direction changing device 17 movable, it is possible to effectively prevent the left and right clips from being caught in the film.
  • the take-up tension T (N / m) of the stretched film can be adjusted within a range of 100 N / m ⁇ T ⁇ 300 N / m, preferably 150 N / m ⁇ T ⁇ 250 N / m. preferable.
  • the ⁇ / 4 retardation film of the present invention may be formed by a melt film forming method.
  • the melt film forming method is a molding method in which a composition containing additives such as a resin and a plasticizer is heated and melted to a temperature exhibiting fluidity, and then a melt containing a fluid thermoplastic resin is cast. .
  • the heating and melting molding method can be classified into a melt extrusion molding method, a press molding method, an inflation method, an injection molding method, a blow molding method, a stretch molding method, and the like.
  • the melt extrusion method is preferable from the viewpoint of mechanical strength and surface accuracy.
  • the plurality of raw materials used in the melt extrusion method are usually preferably kneaded and pelletized in advance.
  • a known method can be applied. For example, dry cellulose acylate, plasticizer, and other additives are fed to an extruder with a feeder and kneaded using a single-screw or twin-screw extruder. It can be obtained by extruding into a strand from a die, water cooling or air cooling and cutting.
  • the additives may be mixed before being supplied to the extruder, or may be supplied by individual feeders.
  • a small amount of additives such as fine particles and antioxidants are preferably mixed in advance in order to mix uniformly.
  • the extruder used for pelletization preferably has a method of processing at as low a temperature as possible so that pelletization is possible so that the shearing force is suppressed and the resin does not deteriorate (molecular weight reduction, coloring, gel formation, etc.).
  • a twin screw extruder it is preferable to rotate in the same direction using a deep groove type screw. From the uniformity of kneading, the meshing type is preferable.
  • Film formation is performed using the pellets obtained as described above.
  • the raw material powder can be put into a feeder as it is, supplied to an extruder, heated and melted, and then directly formed into a film without being pelletized.
  • the melting temperature is in the range of 200 to 300 ° C.
  • T A film is cast from the die, the film is nipped by a cooling roller and an elastic touch roller, and solidified on the cooling roller.
  • the extrusion flow rate is preferably carried out stably by introducing a gear pump.
  • a stainless fiber sintered filter is preferably used as a filter used for removing foreign substances.
  • a stainless steel fiber sintered filter is a product in which a stainless steel fiber body is intricately intertwined and compressed, and the contact points are sintered and integrated. The accuracy can be adjusted.
  • Additives such as plasticizers and fine particles may be mixed with the resin in advance, or may be kneaded in the middle of the extruder. In order to add uniformly, it is preferable to use a mixing apparatus such as a static mixer.
  • the film temperature on the touch roller side when the film is nipped by the cooling roller and the elastic touch roller is preferably in the range of Tg or more and Tg + 110 ° C. or less of the film.
  • a known elastic touch roller can be used as the elastic touch roller having an elastic surface used for such a purpose.
  • the elastic touch roller is also called a pinching rotary body, and a commercially available one can also be used.
  • the film obtained as described above is subjected to stretching and shrinking treatment by the stretching operation after passing through the step of contacting the cooling roller.
  • the stretching and shrinking method a known roller stretching machine or tenter as described above can be preferably used.
  • the stretching temperature is usually preferably in the temperature range of Tg to Tg + 60 ° C. of the resin constituting the film.
  • the end Before winding, the end may be slit and cut to the product width, and knurled (embossed) may be applied to both ends to prevent sticking and scratching during winding.
  • the knurling method can process a metal ring having an uneven pattern on its side surface by heating or pressing.
  • grip part of the clip of both ends of a film is cut out and reused.
  • the film thickness of the ⁇ / 4 retardation film of the present invention is not particularly limited, but can be used in the range of 10 to 250 ⁇ m, preferably in the range of 20 to 100 ⁇ m, more preferably in the range of 40 to 80 ⁇ m. It is within the range, and particularly preferably within the range of 40 to 65 ⁇ m.
  • the ⁇ / 4 retardation film of the present invention may have a width in the range of 1 to 4 m. Furthermore, those having a width of 1.4 to 4 m are preferably used, and particularly preferably 1.6 to 3 m. If it is 4 m or less as a width
  • the arithmetic average roughness Ra of the surface of the ⁇ / 4 retardation film of the present invention is generally in the range of 2.0 nm to 4.0 nm, preferably in the range of 2.5 nm to 3.5 nm.
  • the dimensional change rate (%) of the ⁇ / 4 retardation film of the present invention is preferably less than 0.5%, and more preferably 0.3%. It is preferable that it is less than.
  • defects failures in the film
  • the defects referred to here are those of the solvent in the drying step in film formation by the solution casting method. It refers to voids (foaming defects) in the film caused by rapid evaporation, foreign matters in the film forming solution, and foreign matters (foreign matter defects) in the film caused by foreign matters mixed in the film formation.
  • a defect having a diameter of 5 ⁇ m or more is 1 piece / 10 cm square or less in the film plane. More preferably, it is 0.5 piece / 10 cm square or less, and particularly preferably 0.1 piece / 10 cm square or less.
  • the diameter of the above defect indicates the diameter when the defect is circular, and when the defect is not circular, the range of the defect is determined by observing with a microscope according to the following method, and the maximum diameter (diameter of circumscribed circle) is determined.
  • the defect range is measured by the size of the shadow when the defect is observed with the transmitted light of the differential interference microscope. Further, when the defect is accompanied by a change in the surface shape such as transfer of a roller flaw or an abrasion, the size is confirmed by observing the defect with reflected light of a differential interference microscope.
  • the film When the number of defects is larger than 1/10 cm square, for example, when the film is tensioned during processing in a later process, the film may be broken starting from the defects and productivity may be reduced. Moreover, when the diameter of a defect becomes 5 micrometers or more, it can confirm visually by polarizing plate observation etc., and when used as an optical member, a bright spot may arise.
  • the ⁇ / 4 retardation film of the present invention preferably has a breaking elongation of at least 10% or more in at least one direction (TD direction or MD direction) in the measurement based on JIS-K7127-1999, Preferably it is 20% or more.
  • the upper limit of the elongation at break is not particularly limited, but is practically about 250%. In order to increase the elongation at break, it is effective to suppress defects in the film caused by foreign matter and foaming.
  • the ⁇ / 4 retardation film of the present invention preferably has a total light transmittance of 90% or more, more preferably 93% or more. Moreover, as a realistic upper limit, it is about 99%. In order to achieve excellent transparency expressed by such total light transmittance, it is necessary not to introduce additives and copolymerization components that absorb visible light, or to remove foreign substances in the polymer by high-precision filtration. It is effective to reduce the diffusion and absorption of light inside the film. Also, reduce the surface roughness of the film surface by reducing the surface roughness of the film contact area (cooling roller, calender roller, drum, belt, coating substrate in solution casting, transport roller, etc.) during film formation. It is effective to reduce the diffusion and reflection of light on the film surface.
  • the circularly polarizing plate according to the present invention is produced by cutting a long roll having a long protective film, a long polarizer, and a long ⁇ / 4 retardation film of the present invention in this order. It is preferable.
  • the circularly polarizing plate according to the present invention includes a ⁇ / 4 retardation film that satisfies the conditions specified in claim 1.
  • the ⁇ / 4 retardation film of the present invention is obliquely stretched so that the angle of the slow axis (that is, the orientation angle ⁇ ) is “substantially 45 °” with respect to the longitudinal direction
  • the direction of the maximum elastic modulus is also “substantially 45 °” with respect to the longitudinal direction, and the circularly polarizing plate tends to warp in an oblique direction.
  • “Substantially 45 °” means within the range of 45 ⁇ 5 ° as described above.
  • the polarizer is preferably sandwiched between the ⁇ / 4 retardation film of the present invention and a protective film, and a cured layer is laminated on the viewing side of the protective film. It is preferable because it has an effect of preventing warpage of the plate.
  • the circularly polarizing plate according to the present invention has an ultraviolet absorbing function in order to prevent deterioration due to ultraviolet rays. If the protective film on the viewing side has an ultraviolet absorbing function, both the polarizer and the organic EL element are preferable from the viewpoint of exhibiting the protective effect against ultraviolet rays, but the ⁇ / 4 retardation film on the light emitter side also has an ultraviolet absorbing function. It is preferable that deterioration of the organic EL element can be further suppressed.
  • the organic electroluminescence display device of the present invention comprises a circularly polarizing plate having the ⁇ / 4 retardation film of the present invention and an organic electroluminescence element.
  • a polarizer is placed on an organic EL device having a substrate metal electrode, TFT, organic light emitting layer, transparent electrode (ITO (indium tin oxide), etc.), insulating layer, and sealing layer in this order using glass or polyimide.
  • An organic EL display device can be configured by providing the circularly polarizing plate according to the present invention sandwiched between the ⁇ / 4 retardation film of the present invention and a protective film.
  • the protective film is preferably laminated with a cured layer.
  • the cured layer not only prevents scratches on the surface of the organic EL display device but also has an effect of preventing warpage due to the circularly polarizing plate. Further, an antireflection layer may be provided on the cured layer.
  • the thickness of the organic EL element itself is about 1 ⁇ m.
  • the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative and the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a structure having various combinations such as a laminate of such a light-emitting layer and an electron injection layer made of a perylene derivative, or a stack of these hole injection layer, light-emitting layer, and electron injection layer is known. It has been.
  • holes and electrons are injected into the organic light-emitting layer by applying a voltage to the transparent electrode and the metal electrode, and the energy generated by recombination of these holes and electrons excites the phosphor material. Then, light is emitted on the principle that the excited fluorescent material emits light when returning to the ground state.
  • the mechanism of recombination in the middle is the same as that of a general diode, and as can be predicted from this, the current and the emission intensity show strong nonlinearity with rectification with respect to the applied voltage.
  • an organic EL display device in order to take out light emitted from the organic light emitting layer, at least one of the electrodes needs to be transparent.
  • a transparent electrode formed of a transparent conductor such as indium tin oxide is used as an anode. It is preferable to use it.
  • metal electrodes such as Mg—Ag and Al—Li are used.
  • the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer transmits light almost completely like the transparent electrode. As a result, light that is incident from the surface of the transparent substrate at the time of non-light emission, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode is again emitted to the surface side of the transparent substrate.
  • the display surface of the organic EL display device looks like a mirror surface.
  • an organic EL display device including an organic EL element having a transparent electrode on the surface side of an organic light emitting layer that emits light when a voltage is applied and a metal electrode on the back surface side of the organic light emitting layer, the surface side of the transparent electrode (visible)
  • a polarizing plate can be provided on the side), and a retardation plate can be provided between the transparent electrode and the polarizing plate.
  • the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization action.
  • the retardation plate is composed of a 1 ⁇ 4 retardation film and the angle formed by the polarization direction of the polarizing plate and the retardation plate is adjusted to ⁇ / 4, the mirror surface of the metal electrode can be completely shielded. it can.
  • the external light incident on the organic EL display device is transmitted only by the linearly polarized light component by the polarizing plate, and this linearly polarized light is generally elliptically polarized light by the phase difference plate.
  • the phase difference plate has a ⁇ / 4 position. When the angle formed by the polarization direction of the polarizing film and the retardation plate is ⁇ / 4, it becomes circularly polarized light.
  • This circularly polarized light is transmitted through the transparent substrate, the transparent electrode, and the organic thin film, reflected by the metal electrode, is again transmitted through the organic thin film, the transparent electrode, and the transparent substrate, and becomes linearly polarized light again on the retardation plate. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot permeate
  • Example 1 [Production of ⁇ / 4 retardation film] [Preparation of Protective Film 1]
  • ester compound 1 251 g of 1,2-propylene glycol, 278 g of phthalic anhydride, 91 g of adipic acid, 610 g of benzoic acid, 0.191 g of tetraisopropyl titanate as an esterification catalyst, 2 L four-neck equipped with thermometer, stirrer, and slow cooling tube The flask is charged and gradually heated with stirring until it reaches 230 ° C. in a nitrogen stream.
  • An ester compound 1 was obtained as a plasticizer by performing dehydration condensation reaction for 15 hours, and distilling off unreacted 1,2-propylene glycol under reduced pressure at 200 ° C. after completion of the reaction.
  • the acid value was 0.10 mg KOH / g, and the number average molecular weight was 450.
  • the fine particle addition liquid 1 was prepared as follows.
  • Fine particle dispersion 1 Fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.) 11 parts by mass Ethanol 89 parts by mass The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.
  • Fine particle addition liquid 1 The fine particle dispersion 1 was slowly added to a dissolution tank containing 150 parts by mass of methylene chloride with sufficient stirring. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution 1.
  • the belt casting apparatus was used to uniformly cast on a stainless steel band support.
  • the solvent was evaporated until the residual solvent amount reached 100%, and the stainless steel band support was peeled off.
  • Cellulose ester film web was evaporated at 35 ° C, the solvent was slit to 1.65m width, and stretched in MD direction by 1.30 times in TD direction (film width direction) while applying heat at 160 ° C.
  • the magnification was 1.01 times.
  • the residual solvent amount when starting stretching was 20%. Then, after drying for 15 minutes while transporting the inside of a drying device at 120 ° C.
  • the protective film 1 was obtained.
  • the residual solvent amount of the protective film 1 was 0.2%, the film thickness was 40 ⁇ m, and the number of turns was 3900 m.
  • the orientation angle ⁇ of the protective film 1 was measured using KOBRA-21ADH manufactured by Oji Scientific Instruments, and as a result, it was in the range of 90 ° ⁇ 1 ° with respect to the film longitudinal direction.
  • a main dope having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose acetate A was added to a pressurized dissolution tank containing a solvent while stirring. This is completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope was prepared by filtration using 244.
  • the obtained dope was uniformly cast on a stainless steel belt support at a temperature of 33 ° C. and a width of 2000 mm.
  • the temperature of the stainless steel belt was controlled at 30 ° C.
  • the solvent is evaporated until the residual solvent amount in the cast (cast) film reaches 75%, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m.
  • a raw film was prepared.
  • FIG. 6A is an example of a film forming machine that stretches and shrinks a long film from a raw fabric.
  • the film forming machine shown in FIG. 6A stretches the cellulose acylate film F in the transverse direction S and simultaneously shrinks in the longitudinal direction L.
  • 6B is an enlarged view of a D part of the film forming machine shown in FIG. 6A.
  • the film F to be inserted into the inlet clip wheel 61 is gripped by a large number of clips 71 constituting the clip chain 72 at its end, and conveyed to the outlet clip wheel 62.
  • the inlet clip wheel 61 drives the clip chain 72 via the gear 73 and transports the film F to the outlet clip wheel 2.
  • the outlet clip wheel 62 is a simple wheel having no driving force.
  • the clips 71 are connected to each other by a roller link plate to form a clip chain 72. Further, the clip 71 moves along the clip travel rail 74.
  • the cellulose acylate film F is heated in the oven 63 and is easily formed.
  • the clip 71 positioned on the inlet clip wheel 61 side has a large interval, and the clip 71 positioned on the outlet clip wheel 2 side has a small interval. That is, although not shown, the interval between the clips 71 is gradually reduced while the clip 71 moves from the inlet clip wheel 61 side to the outlet clip wheel 62. As will be described later, the interval between the clips 71 is configured to be gradually narrowed by the adjustment rail 75.
  • the draw ratio described here means that 1.00 times does not stretch or shrink.
  • FIG. 7 shows another example in which the film is drawn from the long film original and then obliquely stretched.
  • the linear distance from the grip start point A1 to B1 where the transport film is gripped for the first time by the gripping tool is Lo, and both of the gripping tools have passed through all the stretching zones in the diagonal stretching tenter.
  • the draw ratio R at this time is preferably in the range of 1.30 to 3.00, more preferably 1.50 to 2.50. When the draw ratio is within this range, thickness unevenness in the width direction is reduced, which is preferable. In the stretching zone of the oblique stretching tenter, if the stretching temperature is differentiated in the width direction, the thickness unevenness in the width direction can be further improved.
  • the raw film produced by producing the ⁇ / 4 retardation film 101 was unwound from the film unwinding step and transported at a transport speed of 5 m / min. Next, the film is obliquely stretched using an oblique stretching machine as shown in FIG. 8A.
  • a zone combination of the diagonal stretch machine at this time, it was set as the combination which has a preheating zone, a lateral stretch zone, an oblique stretch zone, a holding zone, and a cooling zone.
  • the distance between the main shaft of the guide roll closest to the inlet of the oblique stretching machine and the gripping tool (clip gripping part) of the oblique stretching machine was 80 cm.
  • a clip with a length of 2 inches in the conveying direction was used, and a guide roll with a diameter of 10 cm was used.
  • the temperature of the preheating zone was 175 ° C.
  • the temperature of the transverse stretching zone was 175 ° C.
  • the temperature of the oblique stretching zone was 175 ° C.
  • the temperature of the holding zone was 150 ° C.
  • the temperature of the cooling zone was 110 ° C.
  • the take-up tension at the outlet of the drawing machine was 200 N / m.
  • the stretching ratio R at this time was stretched to 1.95 times.
  • the film was stretched so as to be 1.30 times in the transverse stretching zone and 1.50 times in the oblique stretching zone.
  • the film was contracted by 0.62 times in a direction perpendicular to the stretching direction from the point where the stretching ratio was finished up to 1.67 times.
  • the ratio between the shrinkage ratio and the draw ratio is 0.32.
  • the film was stretched in an oblique direction so that the orientation angle ⁇ was 45 °.
  • the stretched film was controlled so that the fluctuation in the take-up tension was less than 3% by performing feedback control in which the change in the tension measured with the first roll on the outlet side of the obliquely stretched tenter was reflected in the take-up motor rotation speed.
  • both ends of the film are trimmed, the conveyance direction is changed by a conveyance direction changing device composed of an air flow roll, and the film is wound by a slidable winding device to obtain a roll-like ⁇ / 4 retardation film 103 having a width of 2000 mm. It was.
  • the film was stretched using a heating device for controlling the temperature in the width direction of the film.
  • the heating device controlled the temperature so that the thickness of the film in the film width direction after stretching was approximately the same as the thickness direction film thickness distribution before stretching.
  • the ⁇ / 4 retardation is the same as the production of the ⁇ / 4 retardation film 101 except that the compound A added to the cellulose acetate solution composition of the raw film is changed to the compound C.
  • a film 106 was produced.
  • a ⁇ / 4 retardation film 109 was produced using the oblique stretching machine shown in FIG. 8B in the step of stretching the original film with an oblique stretching machine described in the preparation of the ⁇ / 4 retardation film 103. Specifically, it is described below.
  • a zone combination of the diagonal stretch machine at this time, it was set as the combination which has a preheating zone, a lateral stretch zone, an oblique stretch zone, a holding zone, and a cooling zone.
  • the distance between the main shaft of the guide roll closest to the inlet of the oblique stretching machine and the gripping tool (clip gripping part) of the oblique stretching machine was 80 cm.
  • a clip with a length of 2 inches in the conveying direction was used, and a guide roll with a diameter of 10 cm was used.
  • the temperature of the preheating zone was 175 ° C.
  • the temperature of the transverse stretching zone was 175 ° C.
  • the temperature of the oblique stretching zone was 175 ° C.
  • the temperature of the holding zone was 150 ° C.
  • the temperature of the cooling zone was 110 ° C.
  • the take-up tension at the outlet of the drawing machine was 200 N / m.
  • the stretching ratio R at this time was stretched to 1.95 times.
  • the film was stretched so as to be 1.30 times in the transverse stretching zone and 1.50 times in the oblique stretching zone. Further, simultaneously with starting the stretching in the oblique direction, the film was contracted 0.62 times in the roll conveying direction.
  • the film was stretched in an oblique direction so that the orientation angle ⁇ was 45 °.
  • the stretched film was controlled so that the fluctuation in the take-up tension was less than 3% by performing feedback control in which the change in the tension measured with the first roll on the outlet side of the obliquely stretched tenter was reflected in the take-up motor rotation speed.
  • both ends of the film are trimmed, the conveyance direction is changed by a conveyance direction changing device composed of an air flow roll, and the film is wound by a slidable winding device to obtain a roll-like ⁇ / 4 retardation film 109 having a width of 2000 mm. It was.
  • the ratio of the shrinkage ratio and the draw ratio was set to 0.32.
  • the film was stretched using a heating device for controlling the temperature in the width direction of the film.
  • the heating device controlled the temperature so that the thickness of the film in the film width direction after stretching was approximately the same as the thickness direction film thickness distribution before stretching.
  • ⁇ / 4 retardation film 110 In the production of the ⁇ / 4 retardation film 101, a ⁇ / 4 retardation film 110 was produced in the same manner as in Example 1 except that the compound A added to the cellulose acetate solution composition of the original film was changed to the compound D.
  • ⁇ / 4 Retardation Film 201 In the production of the ⁇ / 4 phase difference film 101, a comparative ⁇ / 4 phase difference is produced in the same manner as the production of the ⁇ / 4 phase difference film 101 except that the compound A added to the cellulose acetate solution composition of the original film is not added. A film 201 was produced.
  • half width of compounds A to F and the maximum wavelength of the absorption waveform were determined by the method described above.
  • Tables 1 and 2 show the optical characteristics and compound characteristics of the produced ⁇ / 4 retardation films 101 to 113 and 201 to 204, respectively.
  • the ⁇ / 4 retardation films 101 to 113 of the present invention have higher retardation and better wavelength dispersion characteristics than the comparative ⁇ / 4 retardation films 201 to 204. I understand.
  • Example 2 [Production of organic EL display device] (Production of circularly polarizing plates 101 to 113, 201 to 204) A polyvinyl alcohol film having a thickness of 120 ⁇ m was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times).
  • the ⁇ / 4 retardation films 101 to 113 and 201 to 204 produced as described above were bonded to one side of the polarizer using a completely saponified polyvinyl alcohol 5% aqueous solution as an adhesive. At that time, bonding was performed such that the transmission axis of the polarizer and the slow axis of the ⁇ / 4 retardation film were 45 degrees.
  • the protective film 1 was similarly subjected to alkali saponification treatment and bonded to the other surface of the polarizer to produce circularly polarizing plates 101 to 113 and 201 to 204.
  • Organic electroluminescence display An organic electroluminescence display device having the structure described in FIG. 9 was prepared by using the 3 mm-thick 50-inch (127 cm) non-alkali glass.
  • FIG. 9 shows an example of an organic electroluminescence display device.
  • a reflective electrode made of chromium is formed on a transparent glass substrate 1a
  • ITO is formed on the reflective electrode as a metal electrode 2a (anode)
  • poly (3,4) is formed on the anode as a hole transport layer.
  • -Ethylenedioxythiophene) -polystyrene sulfonate (PEDOT: PSS) is formed by sputtering to a thickness of 80 nm, and then a shadow mask is used on the hole transport layer, as shown in FIG. 3aG and 3aB were formed with a film thickness of 100 nm.
  • red light emitting layer 3aR tris (8-hydroxyquinolinate) aluminum (Alq 3 ) as a host and a light emitting compound [4- (dicyanomethylene) -2-methyl-6 (p-dimethylaminostyryl) -4H-pyran] ( DCM) were co-evaporated (mass ratio 99: 1) to form a thickness of 100 nm.
  • the green light emitting layer 3aG was formed to a thickness of 100 nm by co-evaporating Alq 3 as a host and the light emitting compound coumarin 6 (mass ratio 99: 1).
  • the blue light emitting layer 3aB was formed with a thickness of 100 nm by co-evaporating BAlq and a light emitting compound Perylene as a host (mass ratio 90:10).
  • calcium is deposited to a thickness of 4 nm by vacuum deposition as a first cathode having a low work function so that electrons can be efficiently injected onto the light emitting layer, and a second cathode is formed on the first cathode.
  • Aluminum was formed with a thickness of 2 nm.
  • the aluminum used as the second cathode has a role to prevent calcium as the first cathode from being chemically altered when the transparent electrode 4a formed thereon is formed by sputtering. .
  • an organic light emitting layer was obtained.
  • a transparent conductive film was formed to a thickness of 80 nm on the cathode by sputtering.
  • ITO was used as the transparent conductive film.
  • 200 nm of silicon nitride was formed on the transparent conductive film by a CVD method, thereby forming the organic EL element (11a) by using the insulating film 5a.
  • the produced organic EL display devices were organic EL display devices 101 to 113 and 201 to 204 corresponding to the films 101 to 113 and 201 to 204, respectively. Each evaluation result is shown in Table 3.
  • Display performance of organic EL display device A: When the produced EL display device is viewed from the front or other directions without displaying an image, the screen appears black. A: The screen appears black when the produced EL display device is viewed from the front without displaying an image. (Triangle
  • the organic EL display device using the ⁇ / 4 retardation film of the present invention has excellent black reproducibility and reflected light compared to the organic EL display device using the comparative ⁇ / 4 retardation film. This shows that the screen is good without appearing white. Further, even within the present invention, it can be seen that when the shrinkage is started after stretching at 70% of the total stretching process in the stretching process, the generation of wrinkles is excellent.
  • the ⁇ / 4 retardation film of the present invention is a ⁇ / 4 retardation film having high retardation development and good reverse wavelength dispersion, and a circularly polarizing plate and an organic material provided with the ⁇ / 4 retardation film It is suitably used for an electroluminescence display device.

Abstract

Le but de la présente invention est de fournir : un film à différence de phase Lambda/4 ayant une grande capacité de génération de différence de phase et de bonnes propriétés de dispersion de longueur d'onde inverse; et une plaque de polarisation circulaire et un dispositif d'affichage électroluminescent organique, chacun équipé du film à différence de phase lambda/4. Le film à différence de phase lambda/4 selon la présente invention présente des propriétés de dispersion de longueur d'onde telles que : Ro (450)/Ro (550) se situe dans la plage de 0,72 à 0,96 et Ro (550)/Ro (650) se situe dans la plage de 0,83 à 0,98 lorsque la valeur de différence de phase dans le plan mesurée à une longueur d'onde de mesure (lambda (nm)) dans un environnement ayant une température de 23 °C et une humidité relative de 55% est définie comme Ro (lambda), ledit film à différence de phase lambda/4 étant caractérisé par le fait qu'il contient un composé spécifique, dans lequel la demi-largeur (Δλxmax) d'une bande d'absorption d'une longueur d'onde d'absorption maximale attribuée à la chaîne principale (x) du composé et la demi-largeur (Δλymax) d'une bande d'absorption d'une longueur d'onde d'absorption maximale attribuée à une chaîne latérale (y) du composé satisfont la formule : Δλymax / Δλxmax ≥ 2.
PCT/JP2013/056392 2012-03-12 2013-03-08 Film à différence de phase lambda/4, plaque de polarisation circulaire et dispositif d'affichage électroluminescent organique WO2013137123A1 (fr)

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KR1020147025074A KR101636189B1 (ko) 2012-03-12 2013-03-08 λ/4 위상차 필름, 원편광판 및 유기 일렉트로루미네센스 표시 장치

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JP2012053997 2012-03-12
JP2012-053997 2012-03-12

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WO2013137123A1 true WO2013137123A1 (fr) 2013-09-19

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