WO2021107108A1 - Film de contraste de phase et son procédé de production - Google Patents

Film de contraste de phase et son procédé de production Download PDF

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Publication number
WO2021107108A1
WO2021107108A1 PCT/JP2020/044253 JP2020044253W WO2021107108A1 WO 2021107108 A1 WO2021107108 A1 WO 2021107108A1 JP 2020044253 W JP2020044253 W JP 2020044253W WO 2021107108 A1 WO2021107108 A1 WO 2021107108A1
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Prior art keywords
film
retardation film
retardation
solvent
resin
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PCT/JP2020/044253
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English (en)
Japanese (ja)
Inventor
恭輔 井上
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日本ゼオン株式会社
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Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to CN202080080317.4A priority Critical patent/CN114730039B/zh
Priority to JP2021561554A priority patent/JPWO2021107108A1/ja
Priority to KR1020227014875A priority patent/KR20220108037A/ko
Publication of WO2021107108A1 publication Critical patent/WO2021107108A1/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
    • B29C55/04—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique
    • 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
    • B29C55/04—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique
    • B29C55/06—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique parallel with the direction of feed
    • 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
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements

Definitions

  • the present invention relates to a retardation film and a method for producing the same.
  • Patent Documents 1 to 3 Conventionally, a film manufacturing technique using a resin has been proposed (Patent Documents 1 to 3).
  • One of the films manufactured using resin is a retardation film. Since the retardation film has retardation in at least one of the in-plane direction and the thickness direction, it is generally required to have a large birefringence in at least one of the in-plane direction and the thickness direction.
  • the balance between birefringence in the in-plane direction and birefringence in the thickness direction can be expressed by the NZ coefficient.
  • the retardation film can improve display quality such as viewing angle characteristics of a display device.
  • Patent Document 1 proposes a manufacturing method thereof.
  • it is necessary to manufacture a film having a plurality of layers and carry out a shrinkage step and a heating step. Therefore, the number of control items is large and the number of steps is large, so that the manufacturing method tends to be complicated.
  • Patent Document 1 discloses a specific example of producing a single-wafer retardation film, but from the viewpoint that it can be efficiently produced by the roll-to-roll method, the retardation film has a long shape. Is required.
  • the present invention has been devised in view of the above problems, and an object of the present invention is to provide a long retardation film having excellent viewing angle characteristics and a method for producing the same.
  • the present inventor has made diligent studies to solve the above problems. As a result, the present inventor has a slow axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction by stretching the resin film having a predetermined NZ coefficient in the oblique direction, and the NZ coefficient is 0.
  • the present invention includes the following.
  • a long retardation film It has a slow axis at an angle of 10 ° or more and 80 ° or less with respect to its width direction.
  • the retardation film according to [1] which is a 1/2 wave plate or a 1/4 wave plate.
  • the retardation film according to [4], wherein the crystalline polymer is a hydride of a ring-opening polymer of dicyclopentadiene.
  • the method for producing a retardation film according to [9] wherein the step 1 includes bringing the resin film into contact with a solvent to change the NZ coefficient of the resin film to obtain the film F 0. ..
  • the solvent is a hydrocarbon solvent.
  • FIG. 1 is a side view schematically showing an apparatus that can be used in step 1 of the method for manufacturing a retardation film according to the first embodiment.
  • FIG. 2 is a plan view schematically showing a diagonal stretching machine that can be used in step 2 of the method for manufacturing a retardation film according to the first embodiment.
  • FIG. 3 is a plan view schematically showing a longitudinal stretching machine that can be used in an arbitrary process.
  • the birefringence in the in-plane direction of the film is a value represented by "(nx-ny)”, and is therefore represented by "Re / d”, unless otherwise specified.
  • the birefringence in the thickness direction of the film is a value represented by "[ ⁇ (nx + ny) / 2 ⁇ -nz]" unless otherwise specified, and is therefore represented by "Rth / d".
  • the NZ coefficient of the film is a value represented by "(nx-nz) / (nx-ny)", and is therefore represented by "0.5 + Rth / Re", unless otherwise specified.
  • nx represents the refractive index in the direction perpendicular to the thickness direction of the film (in-plane direction) and in the direction in which the maximum refractive index is given.
  • ny represents the refractive index in the in-plane direction of the film and orthogonal to the nx direction.
  • nz represents the refractive index in the thickness direction of the film.
  • d represents the thickness of the film.
  • the measurement wavelength is 590 nm unless otherwise specified.
  • a material having a positive intrinsic birefringence means a material in which the refractive index in the stretching direction is larger than the refractive index in the direction perpendicular to it, unless otherwise specified.
  • a material having a negative intrinsic birefringence means a material in which the refractive index in the stretching direction is smaller than the refractive index in the direction perpendicular to the refractive index, unless otherwise specified.
  • the value of the intrinsic birefringence can be calculated from the permittivity distribution.
  • the diagonal direction of a long film indicates an in-plane direction of the film, which is neither parallel nor perpendicular to the width direction of the film, unless otherwise specified.
  • the "long" film means a film having a length of 5 times or more, preferably 10 times or more, and specifically a roll.
  • the longitudinal direction of the long film is usually parallel to the film transport direction in the production line.
  • the MD direction (machine direction) is the transport direction of the film in the production line, and is usually parallel to the longitudinal direction of the long film.
  • the TD direction (transverse direction) is a direction parallel to the film surface, a direction perpendicular to the MD direction, and usually parallel to the width direction of a long film.
  • the directions of the elements of "parallel”, “vertical” and “orthogonal” include an error within a range that does not impair the effect of the present invention, for example, within a range of ⁇ 5 °, unless otherwise specified. You may be.
  • the retardation film of the present invention is a long retardation film having a slow phase axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction thereof and having an NZ coefficient of more than 0 and less than 1.
  • the retardation film of the present invention has a slow phase axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction and the NZ coefficient is larger than 0 and smaller than 1, reflection in the tilt direction can be reduced. .. As a result, it is possible to achieve a retardation film having excellent viewing angle characteristics. Further, since the retardation film of the present invention has a long shape, it can be efficiently manufactured by the roll-to-roll method.
  • the method for producing a retardation film of the present invention produces a long retardation film having a slow axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction and having an NZ coefficient of more than 0 and less than 1. How to do it.
  • the method for producing a retardation film of the present invention includes a step 1 of preparing a film F 0 having an NZ coefficient of less than 0 , and a step 2 of diagonally stretching the film F 0.
  • a retardation film having an NZ coefficient of more than 0 and less than 1 Conventionally, it has been difficult to manufacture a retardation film having an NZ coefficient of more than 0 and less than 1, but by stretching a film having an NZ coefficient of less than 0 diagonally, a phase difference having an NZ coefficient of more than 0 and less than 1 has been difficult.
  • the film can be manufactured by a simple method. Therefore, according to the present invention, it is easy to manufacture a retardation film having an NZ coefficient larger than 0 and smaller than 1, having a slow axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction, and having excellent viewing angle characteristics. It is possible to do.
  • the retardation film of the present embodiment is a long retardation film having a slow phase axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction and having an NZ coefficient of more than 0 and less than 1.
  • the retardation film may be made of resin.
  • the resin constituting the retardation film contains a polymer.
  • a resin containing a polymer having crystallinity is preferable.
  • Crystallinity polymer refers to a polymer having a melting point Tm (ie, the melting point can be observed with a differential scanning calorimetry (DSC)).
  • a polymer having crystallization may be referred to as a "crystalline polymer”.
  • a resin containing a crystalline polymer may be referred to as a "crystalline resin”. This crystalline resin is preferably a thermoplastic resin.
  • a resin having a positive natural birefringence value means a resin in which the refractive index in the stretching direction is larger than the refractive index in the direction perpendicular to the refractive index, unless otherwise specified.
  • the value of the intrinsic birefringence can be calculated from the permittivity distribution.
  • the polymer contained in the resin constituting the retardation film is a crystalline polymer and has positive intrinsic birefringence.
  • the crystalline polymer preferably contains an alicyclic structure.
  • the polymer containing an alicyclic structure represents a polymer containing an alicyclic structure in the molecule.
  • the polymer containing such an alicyclic structure can be, for example, a polymer obtained by a polymerization reaction using a cyclic olefin as a monomer or a hydride thereof.
  • Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure. Among these, a cycloalkane structure is preferable because it is easy to obtain a retardation film having excellent properties such as thermal stability.
  • the number of carbon atoms contained in one alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less. is there. When the number of carbon atoms contained in one alicyclic structure is within the above range, mechanical strength, heat resistance, and moldability are highly balanced.
  • the ratio of the structural units containing an alicyclic structure to all the structural units is preferably 30% by weight or more, more preferably 50% by weight or more, and particularly preferably 70. Weight% or more. Heat resistance can be improved by increasing the proportion of structural units containing an alicyclic structure as described above.
  • the ratio of structural units containing an alicyclic structure to all structural units may be 100% by weight or less.
  • the remainder other than the structural unit containing the alicyclic structure is not particularly limited and may be appropriately selected depending on the purpose of use.
  • Examples of the crystalline polymer containing an alicyclic structure include the following polymers ( ⁇ ) to ( ⁇ ). Among these, the polymer ( ⁇ ) is preferable because it is easy to obtain a retardation film having excellent heat resistance.
  • Polymer ( ⁇ ) An addition polymer of a cyclic olefin monomer having crystallinity.
  • Polymer ( ⁇ ) A hydride of the polymer ( ⁇ ) that has crystallinity.
  • the crystalline polymer containing an alicyclic structure includes a ring-opening polymer of dicyclopentadiene having crystallinity and a hydride of the ring-opening polymer of dicyclopentadiene. It is more preferable that it is present and has crystallinity. Of these, a hydride of a ring-opening polymer of dicyclopentadiene, which has crystallinity, is particularly preferable.
  • the ratio of the structural unit derived from dicyclopentadiene to all the structural units is usually 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. More preferably, it refers to a polymer of 100% by weight.
  • the hydride of the ring-opening polymer of dicyclopentadiene preferably has a high proportion of racemic diad.
  • the proportion of the repeating unit racemic diad in the hydride of the ring-opening polymer of dicyclopentadiene is preferably 51% or more, more preferably 70% or more, and particularly preferably 85% or more.
  • a high proportion of racemic diads indicates a high degree of syndiotactic stereoregularity. Therefore, the higher the proportion of racemic diad, the higher the melting point of the hydride of the ring-opening polymer of dicyclopentadiene tends to be.
  • the proportion of racemo diads can be determined based on the 13 C-NMR spectral analysis described in Examples below.
  • polymer ( ⁇ ) to the polymer ( ⁇ ) a polymer obtained by the production method disclosed in International Publication No. 2018/062067 can be used.
  • the melting point Tm of the crystalline polymer is preferably 200 ° C. or higher, more preferably 230 ° C. or higher, and preferably 290 ° C. or lower.
  • the crystalline polymer has a glass transition temperature Tg.
  • the specific glass transition temperature Tg of the crystalline polymer is not particularly limited, but is usually 85 ° C. or higher and usually 170 ° C. or lower.
  • the glass transition temperature Tg and melting point Tm of the polymer can be measured by the following methods. First, the polymer is melted by heating, and the melted polymer is rapidly cooled with dry ice. Subsequently, using this polymer as a test piece, the glass transition temperature Tg and melting point Tm of the polymer were measured at a heating rate of 10 ° C./min (heating mode) using a differential scanning calorimeter (DSC). Can be measured.
  • the weight average molecular weight (Mw) of the crystalline polymer is preferably 1,000 or more, more preferably 2,000 or more, preferably 1,000,000 or less, and more preferably 500,000 or less.
  • a crystalline polymer having such a weight average molecular weight has an excellent balance between molding processability and heat resistance.
  • the molecular weight distribution (Mw / Mn) of the crystalline polymer is preferably 1.0 or more, more preferably 1.5 or more, preferably 4.0 or less, and more preferably 3.5 or less.
  • Mn represents a number average molecular weight.
  • a crystalline polymer having such a molecular weight distribution is excellent in molding processability.
  • the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the polymer can be measured as polystyrene-equivalent values by gel permeation chromatography (GPC) using tetrahydrofuran as a developing solvent.
  • the crystallinity of the crystalline polymer contained in the retardation film is not particularly limited, but is usually higher than a certain level.
  • the specific range of crystallinity is preferably 10% or more, more preferably 15% or more, and particularly preferably 30% or more.
  • the upper limit of crystallinity can be, for example, 70% or less.
  • the crystallinity of the crystalline polymer can be measured by X-ray diffraction.
  • one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.
  • the proportion of the crystalline polymer in the crystalline resin is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more.
  • the ratio of the crystalline polymer is not more than the lower limit of the above range, the birefringence expression and heat resistance of the retardation film can be enhanced.
  • the upper limit of the proportion of the crystalline polymer can be 100% by weight or less.
  • the crystalline resin may contain any component in addition to the crystalline polymer.
  • Optional components include, for example, antioxidants such as phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants; light stabilizers such as hindered amine light stabilizers; petroleum waxes, Fishertroph waxes, etc. Waxes such as polyalkylene wax; sorbitol compounds, metal salts of organic phosphoric acid, metal salts of organic carboxylic acids, nucleating agents such as kaolin and talc; diaminostilben derivatives, coumarin derivatives, azole derivatives (eg, benzoxazole derivatives, etc.
  • Fluorescent whitening agents such as benzotriazole derivatives, benzoimidazole derivatives, and benzothiazole derivatives), carbazole derivatives, pyridine derivatives, naphthalic acid derivatives, and imidazolone derivatives; benzophenone-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, benzotriazole-based UV absorbers such as UV absorbers; Inorganic fillers such as talc, silica, calcium carbonate, glass fibers; Colorants; Flame retardants; Flame retardant aids; Antistatic agents; Plastics; Near infrared absorbers; Lubricants; Fillers ; And any polymer other than the crystalline polymer, such as a soft polymer; and the like.
  • the arbitrary component one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.
  • the NZ coefficient of the retardation film of this embodiment is greater than 0 and less than 1.
  • the NZ coefficient of the retardation film is preferably 0.2 or more, more preferably 0.4 or more, preferably 0.8 or less, and more preferably 0.6 or less.
  • a retardation film having an NZ coefficient larger than 0 and smaller than 1 is provided in a display device, it is possible to improve display quality such as viewing angle, contrast, and image quality of the display device.
  • the NZ coefficient of the retardation film can be arbitrarily set according to the use of the retardation film.
  • the NZ coefficient of the retardation film can be calculated from the in-plane retardation Re of the film and the retardation Rth in the thickness direction.
  • the in-plane retardation Re and the thickness direction retardation Rth of the film can be measured using a phase difference meter (for example, "AXoScan OPMF-1" manufactured by AXOMETRICS).
  • the retardation film of the present embodiment has a slow phase axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction thereof.
  • the angle of the slow-phase axis with respect to the film width direction can be adjusted by adjusting the stretching direction in step 2 (diagonal stretching step) of the manufacturing method of the present embodiment.
  • the direction of the slow axis of the retardation film can be arbitrarily set according to the use of the retardation film.
  • the retardation film usually has large birefringence in one or both of the in-plane direction and the thickness direction.
  • the retardation film is usually, 1.0 ⁇ 10 -3 or more in-plane direction of the birefringent Re / d, and, 1.0 ⁇ 10 -3 or more absolute value in the thickness direction of the birefringent One or both of
  • the birefringence Re / d of the retardation film in the in-plane direction is usually 1.0 ⁇ 10 -3 or more, preferably 3.0 ⁇ 10 -3 or more, and particularly preferably 5.0 ⁇ 10 -3. That is all. There is no upper limit, for example, it may be 2.0 ⁇ 10 -2 or less, 1.5 ⁇ 10 -2 or less, or 1.0 ⁇ 10 -2 or less.
  • of the birefringence in the thickness direction of the retardation film is 1.0 ⁇ 10 -3 or more
  • the birefringence Re / d in the in-plane direction of the retardation film is in the above range. Even outside of, it can be a preferred retardation film.
  • of birefringence in the thickness direction of the retardation film is usually 1.0 ⁇ 10 -3 or more, preferably 3.0 ⁇ 10 -3 or more, and particularly preferably 5.0 ⁇ 10 It is -3 or more. There is no upper limit, for example, it may be 2.0 ⁇ 10 -2 or less, 1.5 ⁇ 10 -2 or less, or 1.0 ⁇ 10 -2 or less. However, when the birefringence Re / d in the in-plane direction of the retardation film is 1.0 ⁇ 10 -3 or more, the absolute value
  • the value of the in-plane retardation Re of the retardation film can be set according to the use of the retardation film.
  • the specific value of the in-plane retardation Re of the retardation film can be preferably 100 nm or more, more preferably 110 nm or more, particularly preferably 120 nm or more, and preferably 180 nm or less, more preferably 170 nm or less. , Especially preferably 160 nm or less.
  • the retardation film can function as a quarter wave plate.
  • the specific in-plane retardation Re value of the retardation film can be preferably 230 nm or more, more preferably 250 nm or more, particularly preferably 255 nm or more, and preferably 320 nm or less, more preferably.
  • the retardation film can function as a 1/2 wavelength plate.
  • the value of the retardation Rth in the thickness direction of the retardation film can be set according to the application of the retardation film.
  • the retardation Rth in the specific thickness direction of the retardation film is preferably -30 nm or more, more preferably -15 nm or more, preferably 30 nm or less, and more preferably 15 nm or less.
  • the haze of the retardation film according to the present embodiment is usually less than 1.0%, preferably less than 0.8%, more preferably less than 0.5%, and ideally 0.0%.
  • the haze of the film can be measured using a haze meter (for example, "NDH5000" manufactured by Nippon Denshoku Kogyo Co., Ltd.).
  • the specific total light transmittance of the retardation film is preferably 80% or more, more preferably 85% or more, and particularly preferably 88% or more.
  • the total light transmittance of the retardation film can be measured in the wavelength range of 400 nm to 700 nm using an ultraviolet-visible spectrometer.
  • the thickness d of the retardation film can be appropriately set according to the application of the retardation film.
  • the specific thickness d of the retardation film is preferably 5 ⁇ m or more, more preferably 10 ⁇ m or more, particularly preferably 15 ⁇ m or more, preferably 200 ⁇ m or less, more preferably 100 ⁇ m or less, and particularly preferably 50 ⁇ m or less.
  • the thickness d of the retardation film is not less than the lower limit of the above range, the handleability can be improved and the strength can be increased. Further, when the thickness d of the retardation film is not more than the upper limit value, it is easy to wind up the long retardation film.
  • the retardation film of the present embodiment may contain a solvent when it is manufactured by a manufacturing method including a solvent treatment step described later.
  • the retardation film produced by the production method including the solvent treatment step may contain a solvent.
  • the solvent examples include hydrocarbon solvents such as toluene, limonene, and decalin; carbon disulfide; Of these, hydrocarbon solvents are preferred.
  • the type of the solvent may be one type or two or more types.
  • the ratio of the solvent contained in the retardation film to 100% by weight of the retardation film is preferably 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 0.1% by weight or less. Yes, it can exceed 0% by weight.
  • the solvent content of the retardation film can be measured by the measuring method described in the examples.
  • the retardation film of this embodiment can be manufactured by the method of manufacturing a retardation film described below.
  • the method for producing a retardation film of the present embodiment includes a step 1 of preparing a film F 0 having an NZ coefficient of less than 0 and a step 2 of diagonally stretching the film F 0.
  • FIG. 1 is a side view schematically showing an apparatus that can be used in step 1 of the method for manufacturing a retardation film according to the first embodiment.
  • FIG. 2 is a plan view schematically showing a diagonal stretching machine that can be used in step 2 of the method for manufacturing a retardation film according to the first embodiment.
  • FIG. 3 is a plan view schematically showing a longitudinal stretching machine that can be used in an arbitrary process.
  • a long resin film is prepared, and a masking film is attached to the resin film and wound around a roll to obtain a roll 111 of the resin film.
  • the masking film 12 is peeled off from the film 11 unwound from the roll 111 of the resin film, and the long resin film 1 is conveyed in the direction indicated by A1.
  • the masking film 12 is wound around the roll 112 while being pressed by the nip rolls 101A and 101B arranged at positions sandwiching the film 11 from the thickness direction.
  • the resin film 1 is passed through a bathtub 102 filled with a solvent to bring the resin film 1 into contact with the solvent, and then the film 10 is conveyed into the heating device 103 and dried to obtain the film 10 after the solvent treatment.
  • the NZ coefficient of the resin film 1 changes, and the NZ coefficient becomes less than 0. That is, the film F 0 is obtained by bringing the resin film 1 into contact with the solvent (step 1).
  • the film F 0 (film 10 after solvent treatment) obtained in step 1 is wound while adhering the masking film 13 unwound from the roll 113 to obtain a roll 110 of the film after solvent treatment.
  • the film 10 and the masking film 13 after the solvent treatment are bonded while being pressed by the nip rolls 104A and 104B arranged at positions sandwiching the film from the thickness direction.
  • the masking film is peeled off from the film unwound from the roll 110 of the film after the solvent treatment, and the film 10 after the solvent treatment is conveyed.
  • the solvent-treated film 10 is obliquely stretched by the stretching machine 200 shown in FIG. 2 (step 2).
  • the NZ coefficient of the solvent-treated film changes, and the NZ coefficient becomes larger than 0 and smaller than 1.
  • the average orientation angle with respect to the film width direction is 10 ° or more and 80 °.
  • the stretched film 30 (stretched film 30) is wound while adhering the masking film to obtain a roll 40 of the stretched film.
  • the stretched film 30 can be used as it is as a retardation film.
  • Step 1 is a step of preparing a film F 0 having an NZ coefficient of less than 0.
  • Step 1 may include, for example, bringing the resin film into contact with a solvent, thereby changing the NZ coefficient of the resin film to obtain film F 0 (solvent treatment step).
  • Step 1 can be performed by the apparatus shown in FIG.
  • the device 100 of FIG. 1 includes nip rolls 101A, 101B, 104A and 104B, a bathtub 102 for contacting the resin film 1 with a solvent, and a heating device 103 for drying the resin film after contact with the solvent.
  • Solvent treatment step a resin film is brought into contact with the solvent, thereby changing the NZ coefficient of the resin film is a step of obtaining a film F 0.
  • the solvent penetrates into the resin film. Due to the action of the infiltrated solvent, micro-Brownian motion occurs in the molecules of the polymer in the film, and the molecular chains of the film are oriented.
  • the resin film has a side end surface in addition to the front surface and the back surface which are the main surfaces, most of the surface area of the resin film is occupied by the front surface and the back surface. Therefore, as for the infiltration rate of the solvent, the infiltration rate in the thickness direction through the front surface or the back surface is high. Then, the orientation of the molecules of the polymer can proceed so that the molecules of the polymer are oriented in the thickness direction.
  • the resin film used in the solvent treatment step is a film that is a material for producing a retardation film. Therefore, the resin constituting the resin film can be the same as the resin constituting the retardation film described in "1. Phase difference film”. From the viewpoint that a retardation film having an NZ coefficient of more than 0 and less than 1 can be easily produced, the polymer contained in the resin constituting the resin film is a crystalline polymer and may have a positive intrinsic birefringence. preferable.
  • the crystallinity of the crystalline polymer contained in the resin is preferably small.
  • the specific crystallinity is preferably less than 10%, more preferably less than 5%, and particularly preferably less than 3%. If the crystallinity of the crystalline polymer contained in the resin film before contact with the solvent is low, many molecules of the crystalline polymer can be oriented in the thickness direction by contact with the solvent. The coefficient can be adjusted.
  • the in-plane retardation Re of the resin film is preferably 20 nm or less, more preferably 10 nm or less, and particularly preferably 0.
  • the retardation Rth in the thickness direction of the resin film is preferably 20 nm or less, more preferably 10 nm or less, and particularly preferably 0. Since the Re and Rth of the resin film before the contact with the solvent are in the above ranges, the NZ coefficient of the resin film after the contact with the solvent can be easily set to less than 0.
  • the resin film preferably has a small solvent content, and more preferably does not contain a solvent.
  • the ratio of the solvent contained in the resin film to 100% by weight of the resin film (solvent content) is preferably 1% or less, more preferably 0.5% or less, and particularly preferably 0.1% or less, which is ideal.
  • the target is 0.0%. Since the amount of solvent contained in the resin film before contact with the solvent is small, many polymer molecules can be oriented in the thickness direction by contact with the solvent, so that the NZ coefficient can be adjusted in a wide range. Become.
  • the solvent content of the resin film can be measured by the density.
  • the thickness of the resin film is preferably set according to the thickness of the retardation film to be manufactured. Usually, contact with a solvent increases the thickness of the film. On the other hand, by stretching in step 2, the thickness of the film is reduced. Therefore, the thickness of the resin film may be set in consideration of the change in the thickness in the steps after the step 2.
  • the retardation film can be continuously produced by the roll-to-roll method, so that the productivity of the retardation film can be effectively increased.
  • resin molding methods such as injection molding method, extrusion molding method, press molding method, inflation molding method, blow molding method, calendar molding method, casting molding method, and compression molding method can be used. preferable. Among these, the extrusion molding method is preferable because the thickness can be easily controlled.
  • the production conditions are preferably as follows.
  • the cylinder temperature (molten resin temperature) is preferably Tm or more, more preferably "Tm + 20 ° C.” or more, preferably “Tm + 100 ° C.” or less, and more preferably "Tm + 50 ° C.” or less.
  • the cooling body that the molten resin extruded into a film comes into contact with first is not particularly limited, but a cast roll is usually used.
  • the cast roll temperature is preferably "Tg-50 ° C.” or higher, preferably "Tg + 70 ° C.” or lower, and more preferably "Tg + 40 ° C.” or lower.
  • the cooling roll temperature is preferably "Tg-70 ° C.” or higher, more preferably “Tg-50 ° C.” or higher, preferably “Tg + 60 ° C.” or lower, and more preferably “Tg + 30 ° C.” or lower.
  • Tm represents the melting point of the crystalline polymer
  • Tg represents the glass transition temperature of the crystalline polymer.
  • a film roll is provided in step 1 by winding a masking film on a long resin film and winding it on a roll.
  • Known masking films for example, FF1025 and "FF1035" manufactured by Tredegar; "SAT116T”, “SAT2038T-JSL” and “SAT4538T-JSL” manufactured by Sun A. Kaken Co., Ltd .; "NBO” manufactured by Fujimori Kogyo Co., Ltd.
  • solvent In the solvent treatment step, as the solvent to be brought into contact with the resin film, a solvent that can penetrate into the resin film without dissolving the polymer contained in the resin film can be used.
  • a solvent include hydrocarbon solvents such as toluene, limonene, and decalin; carbon disulfide;
  • hydrocarbon solvents such as toluene, limonene, and decalin
  • carbon disulfide carbon disulfide
  • the resin film is made of a resin containing a crystalline polymer
  • a hydrocarbon-based solvent is preferable as the solvent from the viewpoint that the crystalline polymer can be penetrated into the resin film without being dissolved.
  • the solvent may be one type or two or more types.
  • Examples of the contact method between the resin film and the solvent include a spray method of spraying the solvent on the resin film; a coating method of applying the solvent to the resin film; and a dipping method of immersing the resin film in the solvent. Above all, the dipping method is preferable because continuous contact can be easily performed.
  • FIG. 1 shows a dipping method.
  • the temperature of the solvent in contact with the resin film is arbitrary as long as the solvent can maintain the liquid state, and therefore can be set in the range above the melting point of the solvent and below the boiling point.
  • the time for contacting the resin film with the solvent is not particularly specified, but is preferably 1 second or longer, more preferably 3 seconds or longer, particularly preferably 5 seconds or longer, preferably 180 seconds or shorter, and more preferably 120 seconds. Hereinafter, it is particularly preferably 60 seconds or less.
  • the contact time is equal to or greater than the lower limit of the above range, the NZ coefficient can be effectively adjusted by contact with the solvent.
  • the adjustment amount of the NZ coefficient tends not to change significantly. Therefore, when the contact time is not more than the upper limit value of the above range, the productivity can be improved without impairing the quality of the retardation film.
  • the solvent treatment step may include a step of removing the solvent from the resin film after contact with the solvent.
  • Examples of the method for removing the solvent from the resin film after contact with the solvent include drying and wiping. Above all, it is preferable to perform drying from the viewpoint of quickly removing the solvent to obtain a retardation film having stable characteristics.
  • the solvent When the solvent is removed from the resin film after contact with the solvent by drying, there is no limitation on the method, and it can be performed by using a heating device such as an oven, for example. Specifically, the solvent can be removed by transporting the resin film after contact with the solvent into the heating device for a predetermined time.
  • the drying temperature is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and particularly preferably 80 ° C. or higher. Further, from the viewpoint of suppressing the relaxation of orientation due to heat and maintaining the uniformity of optical characteristics, the drying temperature is preferably Tg + 100 ° C. or lower, more preferably Tg + 80 ° C. or lower, and particularly preferably Tg + 50 ° C. or lower.
  • Tg represents the glass transition temperature of the polymer contained in the resin film.
  • the drying time of the resin film after contact with the solvent is preferably 0.2 minutes or more, more preferably 0.5 minutes or more, particularly preferably 0.8 minutes or more, preferably 10 minutes or less, more preferably. Is 5 minutes or less, particularly preferably 3 minutes or less.
  • the solvent treatment step may be performed in a state where tension is applied to the resin film.
  • the tension applied to the resin film can be applied to either or both of the time when the solvent and the resin film are brought into contact with each other and the time when the resin film is dried after being brought into contact with the solvent.
  • the magnitude of the tension applied to the resin film is preferably set within a range in which the resin film is not substantially stretched by the tension.
  • Substantially stretched means that the stretch ratio of the film in any direction is usually 1.1 times or more.
  • the specific tension range is preferably 2 N / m or more, more preferably 5 N / m or more, particularly preferably 10 N / m or more, and preferably 100 N / m or less, more preferably 70 N / m or less. Especially preferably, it is 50 N / m or less.
  • the unit of tension "N / m" represents the magnitude of tension per 1 m of film size in a direction perpendicular to the tension direction. The magnitude of the tension may be different or the same when the resin film is brought into contact with the solvent and when the resin film is dried after being brought into contact with the solvent.
  • the number of tension directions given to the resin film may be one or plural. Usually, the tension is applied in the in-plane direction perpendicular to the thickness direction of the resin film. Therefore, the tension direction can be one or more in-plane directions. The direction of tension may be different or the same when the resin film is brought into contact with the solvent and when the resin film is dried after being brought into contact with the solvent.
  • the resin film When tension is applied to the resin film as described above, for example, the resin film may be held by an appropriate holder, and the resin film may be pulled by the holder to apply tension.
  • the holder may be one that can continuously hold the entire length of the side of the resin film, or one that can hold the resin film intermittently at intervals.
  • the sides of the resin film may be intermittently held by holders arranged at predetermined intervals.
  • the resin film is tensioned by holding two or more sides of the resin film.
  • tension can be applied to the resin film in the area between the held sides to improve the uniformity of the optical characteristics of the retardation film.
  • a long resin film is obtained from the resin film by holding two sides (that is, long sides) at the end in the width direction and applying tension to the area between the two sides. It is possible to improve the uniformity of optical characteristics over the entire surface of the retardation film.
  • the holder it is preferable that the holder does not come into contact with the resin film except for the sides of the resin film. By using such a holder, a retardation film having more excellent smoothness can be obtained.
  • Suitable holders include, for example, a gripper provided in a tenter stretching machine that can grip the film.
  • the NZ coefficient of film F 0 is less than 0, preferably -1 or less. By having an NZ coefficient in such a range, the retardation film of the present invention can be easily produced.
  • the lower limit of the NZ coefficient of the film F 0 is not particularly limited, but may be, for example, -40 or more.
  • Other optical properties of film F 0 can be adjusted as appropriate to obtain the desired retardation film.
  • the in-plane retardation Re of the film F 0 is preferably 300 nm or less, more preferably 200 nm or less.
  • the lower limit of the in-plane retardation Re of the film F 0 is not particularly limited, but may be, for example, 0 nm or more.
  • the retardation Rth of the film F 0 in the thickness direction is preferably ⁇ 50 nm or less, more preferably ⁇ 150 nm or less.
  • the lower limit of the retardation Rth in the thickness direction of the film F 0 is not particularly limited, but may be, for example, ⁇ 500 nm or more.
  • step 2 The film F 0 obtained by performing step 1 is subjected to the next step (step 2).
  • Step 2 is a step of diagonally stretching the film F 0.
  • the film F 0 is a film obtained by performing the step 1, and in the present embodiment, the film 10 after the solvent treatment obtained in the step 1 corresponds to the film F 0.
  • “stretching diagonally” means stretching a long film in an oblique direction.
  • a retardation film having a slow phase axis at an angle of 10 ° or more and 80 ° C. or less with respect to the film width direction and having an NZ coefficient larger than 0 and smaller than 1 can be obtained.
  • the mechanism by which the film F 0 is obliquely stretched to obtain a film having an NZ coefficient larger than 0 and smaller than 1 is estimated as follows.
  • the retardation Rth in the thickness direction of the film can be greatly changed from a negative value toward zero, and at the same time, the Re value can be increased, whereby the NZ coefficient can be increased. It is estimated that a film in the range of greater than 0 and less than 1 can be obtained.
  • Step 2 can be performed by, for example, the diagonal stretching machine 200 shown in FIG.
  • FIG. 2 illustrates a tenter stretching machine as an example of the diagonal stretching machine 200.
  • the tenter stretching machine 200 horizontally conveys the solvent-treated film 10 (film F 0 ) obtained by peeling the masking film from the film unwound from the feeding roll 110 in an oven heating environment (not shown). , A device for extending in the diagonal direction.
  • the tenter stretching machine 200 includes a plurality of grippers 210R and 210L capable of gripping both ends 10A and 10B of the film 10 after solvent treatment, and both sides of the film transport path for guiding the grippers 210R and 210L, respectively. It is provided with a pair of guide rails 220R and 220L provided in the above.
  • the grippers 210R and 210L are provided so as to be able to travel along the guide rails 220R and 220L. Further, the grippers 210R and 210L are provided so as to be able to travel at a constant speed while maintaining a constant interval with the front and rear grippers 210R and 210L. Further, the grippers 210R and 210L grip the both end portions 10A and 10B in the width direction of the solvent-treated film 10 sequentially supplied to the tenter stretching machine 200 at the inlet portion 230 of the tenter stretching machine 200, and hold the tenter stretching machine 200. It is provided so that it can be opened at the exit portion 240 of 200.
  • the guide rails 220R and 220L have asymmetrical shapes according to conditions such as the direction of the slow axis of the retardation film to be manufactured and the draw ratio.
  • the tenter stretching machine 200 shown in FIG. 2 is provided with a stretching zone 250 in which the distance between the guide rails 220R and 220L becomes wider toward the downstream.
  • the shapes of the guide rails 220R and 220L are such that the grippers 210R and 210L guided by the guide rails 220R and 220L bend the traveling direction of the film 10 after the solvent treatment to the left.
  • the shape is set so that the film 10 after the solvent treatment can be conveyed, and the moving distance of one gripper 210R is longer than the moving distance of the other gripper 210L.
  • the traveling direction of a long film means the moving direction of the midpoint in the width direction of the film unless otherwise specified.
  • "right” and “left” indicate directions when observing from upstream to downstream in the transport direction unless otherwise specified.
  • the guide rails 220R and 220L have an endless continuous track so that the grippers 210R and 210L can orbit a predetermined track. Therefore, the tenter stretching machine 200 has a structure in which the grippers 210R and 210L in which the solvent-treated film 10 is opened at the outlet portion 240 of the tenter stretching machine 200 can be sequentially returned to the inlet portion 230.
  • step 2 the film 10 after the solvent treatment using such a tenter stretching machine 200 is stretched as follows.
  • the film 10 after the solvent treatment obtained after the film is unwound from the feeding roll 110 and the masking film (not shown) is peeled off is continuously supplied to the tenter stretching machine 200.
  • the tenter stretching machine 200 sequentially grips both ends 10A and 10B of the film 10 after solvent treatment at its inlet 230 by the grippers 210R and 210L.
  • the solvent-treated film 10 gripping both ends 10A and 10B is conveyed as the grippers 210R and 210L travel.
  • the shapes of the guide rails 220R and 220L are set so that the traveling direction of the film 10 after the solvent treatment is bent to the left. Therefore, the distance of the track that one gripper 210R travels while gripping the film 10 after the solvent treatment is longer than the distance of the track that the other gripper 210L travels while gripping the film 10 after the solvent treatment. .. Therefore, the set of grippers 210R and 210L that faced each other in the direction perpendicular to the traveling direction of the film 10 after the solvent treatment at the inlet portion 230 of the tenter stretching machine 200 were introduced at the outlet portion 240 of the tenter stretching machine 200.
  • the film 10 after the solvent treatment is stretched in an oblique direction to obtain a long stretched film 30 (broken line L D1 in FIG. 2). , L D2 and L D3 ).
  • the obtained stretched film 30 is released from the grippers 210R and 210L at the outlet portion 240 of the tenter stretching machine 200, is wound up, and is collected as a roll 40.
  • the draw ratio in step 2 is preferably 1.1 times or more, more preferably 1.2 times or more, preferably 5 times or less, and more preferably 2 times or less.
  • the stretching temperature T1 in step 2 is preferably Tg ° C. or higher, more preferably Tg + 2 ° C. or higher, particularly preferably Tg + 5 ° C. or higher, preferably Tg + 40 ° C. or lower, more preferably Tg + 35 ° C. or lower, and particularly preferably Tg + 30 ° C. or lower. is there.
  • Tg refers to the glass transition temperature of the polymer contained in the film 10 after the solvent treatment.
  • the stretching temperature T1 in step 2 means the temperature in the stretching zone 250 of the tenter stretching machine 200.
  • the molecules contained in the stretched film 30 are oriented because they were stretched in step 2. Therefore, the stretched film 30 has a slow phase axis. Since stretching is performed in the oblique direction in step 2, the slow axis of the stretched film 30 is expressed in the oblique direction of the stretched film. Specifically, the stretched film 30 has a slow phase axis in the range of 5 ° to 85 ° with respect to the width direction thereof.
  • the specific direction of the slow phase axis of the stretched film 30 can be set according to the direction of the slow phase axis of the wave plate to be manufactured.
  • the specific direction of the slow-phase axis of the stretched film 30 can be adjusted according to the stretching conditions in step 2 described above.
  • the direction of the slow axis of the stretched film 30 is adjusted by adjusting the feeding angle ⁇ formed by the feeding direction D20 of the film 10 after the solvent treatment from the feeding roll 110 and the winding direction D30 of the stretched film 30.
  • the feeding direction D20 of the film 10 after the solvent treatment indicates the traveling direction of the film 10 after the solvent treatment being fed from the feeding roll 110.
  • the winding direction D30 of the stretched film 30 indicates the traveling direction of the stretched film 30 wound as the roll 40.
  • the stretched film 30 obtained after performing step 2 can be used as it is as the retardation film of the present invention, but the film obtained by performing a further step (for example, a longitudinal stretching step) can also be used as the retardation film of the present invention. Good.
  • the production method of the present embodiment may include a step of performing a preheat treatment for heating the film after the solvent treatment to a stretching temperature before performing the step 2.
  • the preheating temperature and the stretching temperature are the same, but may be different.
  • the preheating temperature is preferably T1-10 ° C. or higher, more preferably T1-5 ° C. or higher, preferably T1 + 5 ° C. or lower, and more preferably T1 + 2 ° C. or lower with respect to the stretching temperature T1.
  • the preheating time is arbitrary, preferably 1 second or longer, more preferably 5 seconds or longer, and preferably 60 seconds or shorter, more preferably 30 seconds or shorter.
  • the manufacturing method of the present embodiment may include a step of vertically stretching the film before or after performing the step 2.
  • longitudinal stretching means stretching a long film in the longitudinal direction.
  • FIG. 3 shows an example in which the stretched film 30 obtained by performing the step 2 is further vertically stretched, but the film before the step 2 (the film 10 after the solvent treatment) is vertically stretched using the stretching machine. After stretching, step 2 may be performed.
  • the roll stretching machine 300 is a device for stretching the film 30 unwound from the roll 40 in the longitudinal direction thereof.
  • the longitudinal stretching step may be performed in a heating environment using an oven (not shown).
  • the roll stretching machine 300 includes an upstream roll 310 and a downstream roll 320 as nip rolls capable of transporting the film 30 in the longitudinal direction in order from the upstream in the transport direction.
  • the rotation speed of the downstream roll 320 is set to be faster than the rotation speed of the upstream roll 310.
  • Stretching of the film 30 using the roll stretching machine 300 is performed as follows.
  • the film 30 is unwound from the roll 40, and the film 30 is continuously supplied to the roll stretching machine 300.
  • the roll stretching machine 300 conveys the supplied film 30 in the order of the upstream roll 310 and the downstream roll 320.
  • the film 30 is stretched in the longitudinal direction.
  • both ends 31 and 32 in the width direction of the film 30 are not restrained. Therefore, usually, the width of the film 30 shrinks with stretching in the longitudinal direction, so that a film 50 having a width smaller than that of the film 30 can be obtained.
  • the film 50 is obtained as a biaxially stretched film stretched in two directions, a longitudinal direction and an oblique direction. After that, both ends of the film 50 are trimmed if necessary, and then the film 50 is wound up and collected as a roll 60.
  • the stretching ratio in the longitudinal stretching step is preferably smaller than the stretching ratio in step 2. This makes it possible to stretch a film having a slow-phase axis in an oblique direction while suppressing the occurrence of wrinkles.
  • the stretching temperature in the longitudinal stretching step can be set in consideration of the stretching temperature in step 2 and the in-plane retardation of the retardation film which is the target product.
  • the manufacturing method of the present embodiment may include a step of removing the solvent adhering to the stretched film (phase difference film) after the step 2.
  • Examples of the method for removing the solvent from the stretched film include the same method as the method for removing the solvent described in step 1.
  • a long retardation film can be manufactured, but in the manufacturing method of the retardation film, the long retardation film thus manufactured is cut out into a desired shape.
  • the process may be included.
  • the retardation film of the present embodiment and the retardation film manufactured by the manufacturing method of the present embodiment have a slow axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction thereof, and the NZ coefficient is from 0. Larger and smaller than 1. Therefore, the retardation film of the present embodiment can be used as a 1/2 wave plate or a 1/4 wave plate.
  • the reflectance in the tilt direction can be reduced.
  • both the 1/2 wave plate and the 1/4 wave plate are made of the retardation film of the present embodiment, the effect of reducing the reflectance in the tilt direction can be made more excellent.
  • the retardation film of the present embodiment has a slow phase axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction and the NZ coefficient is larger than 0 and smaller than 1, it is possible to reduce reflection in the tilt direction. it can. As a result, it is possible to achieve a retardation film having excellent viewing angle characteristics. Further, since the retardation film of the present embodiment has a long shape, it can be efficiently manufactured by the roll-to-roll method.
  • a retardation film having an NZ coefficient greater than 0 and smaller than 1 can be produced by a simple method. Therefore, according to the present embodiment, it is easy to obtain a retardation film having an NZ coefficient larger than 0 and smaller than 1, having a slow axis at an angle of 10 ° or more and 80 ° or less with respect to the width direction, and having excellent viewing angle characteristics. It is possible to manufacture.
  • the glass transition temperature Tg and the melting point Tm of the polymer were measured as follows. First, the polymer was melted by heating, and the melted polymer was rapidly cooled with dry ice. Subsequently, using this polymer as a test piece, the glass transition temperature Tg and melting point Tm of the polymer were measured at a heating rate of 10 ° C./min (heating mode) using a differential scanning calorimeter (DSC). It was measured.
  • the ratio of racemic diads in the polymer was measured as follows. Orthodichlorobenzene -d 4 as solvent, at 200 ° C., by applying the inverse-gated decoupling method, was 13 C-NMR measurement of the polymer. In the results of this 13 C-NMR measurement, the signal of 43.35 ppm derived from meso-diad and the signal of 43.43 ppm derived from racemic diad were obtained with the peak of 127.5 ppm of orthodichlorobenzene-d 4 as a reference shift. Was identified. Based on the intensity ratios of these signals, the proportion of racemic diads in the polymer was determined.
  • the thickness of the film was measured using a contact type thickness gauge (Code No. 543-390 manufactured by Mitutoyo Co., Ltd.).
  • the in-plane retardation Re of the film, the retardation Rth in the thickness direction, and the NZ coefficient were measured by Axo Scan OPMF-1 manufactured by AXOMETRICS. At this time, the measurement was performed at a wavelength of 590 nm. In addition, the NZ coefficient was calculated from the obtained in-plane retardation Re and the thickness direction retardation Rth.
  • the crystallinity of the film was measured by X-ray diffraction.
  • a D8 DISCOVER manufactured by Bruker was used as the measuring device.
  • a mirror having a flat reflecting surface was prepared. The mirror was placed so that the reflecting surface was horizontal and facing upward. A circular polarizing plate was attached on the reflective surface of the mirror so that the polarizing film side was facing upward.
  • the circularly polarizing plate on the mirror was visually observed while illuminating the circularly polarizing plate with sunlight on a sunny day.
  • the observation was carried out in the tilting direction of the circularly polarizing plate with a polar angle of 45 ° and an azimuth angle of 0 ° to 360 °.
  • the above visual evaluation was performed by 20 observers, and each person ranked the results of all the examples and comparative examples, and the points corresponding to the rankings (1st place 6 points, 2nd place 5 points, ... ⁇ The lowest 1 point) was given.
  • the total scores scored by each person for each example and comparative example were arranged in the order of scores, and evaluated in the order of A, B, C, D from the top group in the range of scores.
  • the range of points is an equally divided range (A: 91 to 120 points, B: 61 to 90 points, C: 31 to 60 points, D: 0 to 30 points).
  • the reflectance when the circularly polarizing plate was irradiated with light from the D65 light source was calculated in the inclination direction of the circularly polarizing plate.
  • the tilt direction at a polar angle of 45 °, calculations are performed every 5 ° in the azimuth direction in the range of the azimuth angle of 0 ° to 360 °, and the average of the calculated values is averaged by the modeled circular polarizing plate. It was adopted as the reflectance in the tilt direction.
  • the surface reflection component actually generated on the surface of the polarizing film is excluded from the reflectance.
  • 0.014 parts of the tetrachlorotungsten phenylimide (tetrahydrofuran) complex was dissolved in 0.70 parts of toluene to prepare a solution.
  • 0.061 part of a diethylaluminum ethoxide / n-hexane solution having a concentration of 19% was added, and the mixture was stirred for 10 minutes to prepare a catalytic solution.
  • This catalyst solution was added to a pressure resistant reactor to initiate a ring-opening polymerization reaction. Then, the reaction was carried out for 4 hours while maintaining 53 ° C. to obtain a solution of a ring-opening polymer of dicyclopentadiene.
  • the number average molecular weight (Mn) and weight average molecular weight (Mw) of the obtained ring-opening polymer of dicyclopentadiene are 8,750 and 28,100, respectively, and the molecular weight distribution (Mw / Mn) obtained from these. was 3.21.
  • the hydride contained in the reaction solution and the solution were separated using a centrifuge and dried under reduced pressure at 60 ° C. for 24 hours to obtain a hydride of a crystalline ring-opening polymer of dicyclopentadiene 28. I got 5 copies.
  • the hydrogenation rate of this hydride was 99% or more, the glass transition temperature Tg was 93 ° C., the melting point (Tm) was 262 ° C., and the ratio of racemo diad was 89%.
  • a mixture of a hydride of a ring-opening polymer of dicyclopentadiene and an antioxidant was formed into a strand by hot melt extrusion molding, and then shredded with a strand cutter to obtain a pellet-shaped crystalline resin.
  • This crystalline resin is a resin having a positive intrinsic birefringence value.
  • Example 1 (1-1) Production of Resin Film
  • the pellet-shaped crystalline resin produced in Production Example 1 is molded using a heat melt extrusion film forming machine equipped with a T-die, and a resin film having a width of about 600 mm is formed at a predetermined speed.
  • a roll of the resin film was obtained by the method of winding the resin film into a roll.
  • the line speed was adjusted so that the thickness of the resin film was 18 ⁇ m.
  • FF1025 manufactured by Tredegar Co., Ltd.
  • step 1 The film was pulled out from the roll of the resin film obtained in (1-1), the masking film was continuously peeled off, and the resin film was conveyed. This resin film was passed through a bathtub filled with toluene as a solvent to bring toluene into contact with the resin film. The contact time with the solvent was 7 seconds. A resin film contacted with a solvent was passed through an oven heated to 110 ° C. in the oven for about 1 minute to obtain a film after solvent treatment. During this step, a tension of 20 N / m was applied to the resin film. The solvent-treated film was wound while being protected by a new masking film (“FF1025” manufactured by Tredegar) to obtain a roll of the solvent-treated film.
  • FF1025 new masking film
  • Re was 7 nm
  • Rth was ⁇ 202 nm
  • the NZ coefficient was ⁇ 28.4
  • the thickness was 23 ⁇ m.
  • the slow axis of the film after solvent treatment was a direction parallel to the longitudinal direction of the film.
  • step 2 The film was pulled out from the roll of the film after the solvent treatment obtained in (1-2), the masking film was continuously peeled off, and the film after the solvent treatment was conveyed.
  • the film after the solvent treatment was obliquely stretched using the tenter stretching machine shown in FIG. 2 to obtain a long stretched film (phase difference film).
  • the stretching conditions were a stretching ratio of 1.5 times and a stretching temperature of 130 ° C.
  • the average orientation angle formed by the slow axis of the obtained retardation film with respect to the width direction of the film was 15 °.
  • the obtained retardation film was wound while being bonded to a new masking film (“FF1025” manufactured by Tredegar Co., Ltd.) for protection after trimming both ends in the width direction to obtain a roll of the retardation film.
  • FF1025 new masking film manufactured by Tredegar Co., Ltd.
  • Re was 140 nm
  • Rth was -5 nm
  • NZ coefficient was 0.5
  • thickness was 15 ⁇ m
  • solvent content was 1%. It was.
  • the crystallinity of the retardation film was measured and found to be 22%.
  • Example 2 (2-1) Production of Resin Film In Example 1 (1-1), except that the line speed was adjusted and molding was performed so that the thickness of the resin film was 35 ⁇ m. The same operation as in 1-1) was carried out to obtain a roll of the resin film.
  • the film was pulled out from the roll of the film after the solvent treatment obtained in the diagonal stretching step (2-2), the masking film was continuously peeled off, and the film after the solvent treatment was conveyed.
  • the solvent-treated film was obliquely stretched using the tenter stretching machine shown in FIG. 2 to obtain a long retardation film.
  • the stretching conditions were a stretching ratio of 1.3 times and a stretching temperature of 130 ° C.
  • the average orientation angle formed by the slow axis of the obtained retardation film with respect to the width direction of the film was 75 °.
  • the obtained retardation film was wound while being bonded to a new masking film (“FF1025” manufactured by Tredegar Co., Ltd.) for protection after trimming both ends in the width direction to obtain a roll of the retardation film.
  • FF1025 manufactured by Tredegar Co., Ltd.
  • Re 270 nm
  • Rth 10 nm
  • the NZ coefficient 0.5
  • the thickness was 34 ⁇ m
  • the solvent content was 1%. It was.
  • the crystallinity of the retardation film was measured and found to be 20%.
  • Example 3 In (1-3) of Example 1, the slow axis of the retardation film is set with respect to the width direction of the film by using the roll of the film after the solvent treatment obtained in (1-2) of Example 1.
  • a retardation film was obtained by performing the same operation as in (1-3) of Example 1 except that the film was stretched so that the average orientation angle of the film was 45 °.
  • the obtained retardation film was wound while being bonded to a new masking film (“FF1025” manufactured by Tredegar Co., Ltd.) for protection after trimming both ends in the width direction to obtain a roll of the retardation film.
  • FF1025 manufactured by Tredegar Co., Ltd.
  • Re was 135 nm
  • Rth was 6 nm
  • the NZ coefficient was 0.5
  • the thickness was 15 ⁇ m
  • the solvent content was 1%. It was.
  • the crystallinity of the retardation film was measured and found to be 22%.
  • Re 140 nm
  • Rth 79 nm
  • the NZ coefficient 1.1
  • the thickness 20 ⁇ m
  • the solvent content 0%. It was.
  • the crystallinity of the retardation film was measured and found to be 0%.
  • the resin constituting the obtained resin film was a resin having a positive intrinsic birefringence value.
  • the resin was a resin containing an amorphous polymer.
  • Re 140 nm
  • Rth 78 nm
  • the NZ coefficient 1.1
  • the thickness 20 ⁇ m
  • the solvent content 0%. It was.
  • the crystallinity of the retardation film was measured and found to be 0%.
  • Re 190 nm
  • Rth 115 nm
  • the NZ coefficient 1.1
  • the thickness 47 ⁇ m
  • the solvent content 0%. It was.
  • the average orientation angle formed by the slow axis of the obtained retardation film in the width direction was 75 °, the NZ coefficient was 1.15, the in-plane retardation Re was 260 nm, and the thickness was 40 ⁇ m.
  • the crystallinity of the retardation film was measured and found to be 0%.
  • the obtained retardation film was wound up while being bonded to a new masking film (“FF1025” manufactured by Tredegar Co., Ltd.) for protection.
  • (A-2) Manufacture of circularly polarizing plate
  • a polarizing film (“HLC2-5618S” manufactured by Sanritz Co., Ltd., a polarized light having a thickness of 180 ⁇ m and a polarization transmission axis in a direction of 0 ° with respect to a width direction).
  • HLC2-5618S manufactured by Sanritz Co., Ltd.
  • One surface of the polarizing film and the surface of the optical laminate obtained in (A-1) on the 1/2 wave plate side are made parallel to each other in the longitudinal direction of the polarizing film and the longitudinal direction of the optical laminate. It was bonded via an adhesive layer (“CS9621” manufactured by Nitto Denko).
  • Table 2 shows the evaluation results of each circularly polarizing plate together with the retardation film used for manufacturing the circularly polarizing plate and its physical property values (Re, Rth, NZ coefficient).
  • NZ coefficient is greater than 0 less than 1-position
  • the manufacturing method for obtaining the retardation film is shown, the retardation film of the present invention is not limited to the one manufactured by the manufacturing method.
  • the film has a slow axis of 10 ° or more and 80 ° or less with respect to the film width direction, and the NZ coefficient is A retardation film greater than 0 and less than 1 may be produced.

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  • Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Polarising Elements (AREA)
  • Liquid Crystal (AREA)

Abstract

L'invention concerne un film de contraste de phase allongé, le film de contraste de phase ayant un axe lent à un angle de 10 à 80° (inclus) par rapport à la direction de la largeur de celui-ci, et étant tel que le coefficient NZ est supérieur à 0 et inférieur à 1. Le film de contraste de phase est de préférence une plaque de demi-longueur d'onde ou une plaque quart d'onde, et de préférence, est formé à partir d'une résine ayant une valeur de biréfringence intrinsèque positive. Le film de contraste de phase est également de préférence formé à partir d'une résine qui contient un polymère cristallin et, de préférence, est telle que le polymère cristallin est un hydrure d'un polymère à cycle ouvert de dicyclopentadiène.
PCT/JP2020/044253 2019-11-29 2020-11-27 Film de contraste de phase et son procédé de production WO2021107108A1 (fr)

Priority Applications (3)

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CN202080080317.4A CN114730039B (zh) 2019-11-29 2020-11-27 相位差膜及其制造方法
JP2021561554A JPWO2021107108A1 (fr) 2019-11-29 2020-11-27
KR1020227014875A KR20220108037A (ko) 2019-11-29 2020-11-27 위상차 필름 및 그 제조 방법

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JP2019-216211 2019-11-29
JP2019216211 2019-11-29

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WO2021107108A1 true WO2021107108A1 (fr) 2021-06-03

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JP (1) JPWO2021107108A1 (fr)
KR (1) KR20220108037A (fr)
CN (1) CN114730039B (fr)
TW (1) TW202122841A (fr)
WO (1) WO2021107108A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010266723A (ja) * 2009-05-15 2010-11-25 Nippon Zeon Co Ltd 位相差フィルムの製造方法、位相差フィルム、円偏光フィルム、円偏光板、および液晶表示装置
WO2017150495A1 (fr) * 2016-02-29 2017-09-08 日本ゼオン株式会社 Film étiré, son procédé de fabrication, plaque de polarisation circulaire, et dispositif d'affichage
WO2018139638A1 (fr) * 2017-01-30 2018-08-02 日本ゼオン株式会社 Dispositif d'affichage

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5755675B2 (ja) * 2013-03-29 2015-07-29 日東電工株式会社 位相差フィルムの製造方法および円偏光板の製造方法
CN105765424A (zh) * 2013-11-15 2016-07-13 日本瑞翁株式会社 相位差膜的制造方法
JP2016212171A (ja) 2015-05-01 2016-12-15 日本ゼオン株式会社 光学積層体、円偏光板及び有機エレクトロルミネッセンス表示装置
US10712487B2 (en) 2015-10-15 2020-07-14 Zeon Corporation Phase difference film and production method for the same
JP6877945B2 (ja) 2015-11-30 2021-05-26 日東電工株式会社 位相差層付偏光板および画像表示装置
US10935835B2 (en) * 2016-08-08 2021-03-02 Zeon Corporation Optically anisotropic laminate, polarizing plate, and image display device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010266723A (ja) * 2009-05-15 2010-11-25 Nippon Zeon Co Ltd 位相差フィルムの製造方法、位相差フィルム、円偏光フィルム、円偏光板、および液晶表示装置
WO2017150495A1 (fr) * 2016-02-29 2017-09-08 日本ゼオン株式会社 Film étiré, son procédé de fabrication, plaque de polarisation circulaire, et dispositif d'affichage
WO2018139638A1 (fr) * 2017-01-30 2018-08-02 日本ゼオン株式会社 Dispositif d'affichage

Also Published As

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KR20220108037A (ko) 2022-08-02
JPWO2021107108A1 (fr) 2021-06-03
CN114730039A (zh) 2022-07-08
TW202122841A (zh) 2021-06-16
CN114730039B (zh) 2024-04-23

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