WO2022163416A1 - Film optique, son procédé de production et film polarisant - Google Patents

Film optique, son procédé de production et film polarisant Download PDF

Info

Publication number
WO2022163416A1
WO2022163416A1 PCT/JP2022/001457 JP2022001457W WO2022163416A1 WO 2022163416 A1 WO2022163416 A1 WO 2022163416A1 JP 2022001457 W JP2022001457 W JP 2022001457W WO 2022163416 A1 WO2022163416 A1 WO 2022163416A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
film
resin
optical film
polymer
Prior art date
Application number
PCT/JP2022/001457
Other languages
English (en)
Japanese (ja)
Inventor
浩成 摺出寺
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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 JP2022578252A priority Critical patent/JPWO2022163416A1/ja
Publication of WO2022163416A1 publication Critical patent/WO2022163416A1/fr

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D7/00—Producing flat articles, e.g. films or sheets
    • B29D7/01—Films or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • 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 an optical film, a manufacturing method thereof, and a polarizing film.
  • Display devices such as liquid crystal display devices and organic electroluminescence display devices sometimes use optical films including layers formed from resin.
  • a resin containing a polymer having excellent heat resistance and having crystallinity is sometimes used (for example, Patent Documents 1 to 3).
  • a resin containing a polymer having crystallinity (hereinafter also referred to as a crystalline resin) has excellent heat resistance. In some cases, the adhesion with other resin layers such as a hard coat layer was insufficient. Therefore, by combining a layer of a crystalline resin and a layer of a resin containing an amorphous polymer (hereinafter also referred to as an amorphous resin), adhesion between the crystalline resin layer and another resin layer can be improved. I tried to improve the performance, but sometimes it wasn't enough.
  • an optical film containing a layer of a crystalline resin and having good adhesion to other resin layers; a method for producing the same; and a polarizing film containing the optical film are desired.
  • the present inventors have conducted extensive studies to solve the above problems. As a result, it was found that the above problems can be solved by combining a crystalline resin layer with an amorphous resin layer having a predetermined plane orientation coefficient and by setting the NZ coefficient of the optical film to a predetermined range. I completed the present invention. That is, the present invention provides the following.
  • the inherent birefringence of the resin (a) is positive.
  • the layer (B) includes a first layer (B) and a second layer (B), and between the first layer (B) and the second layer (B), the layer The optical film according to any one of [1] to [7], wherein (A) is arranged.
  • a method for producing an optical film comprising: [11] The method for producing an optical film according to [10], further comprising a step (4) of stretching the laminated film after the step (3).
  • an optical film comprising a crystalline resin layer and having good adhesion to other resin layers; a method for producing the same; and a polarizing film comprising the optical film. can.
  • FIG. 1 is a cross-sectional view schematically showing an optical film according to one embodiment of the invention.
  • FIG. 2 is a cross-sectional view schematically showing a polarizing film according to one embodiment of the invention.
  • a "long" film refers to a film having a length of 5 times or more, preferably 10 times or more, with respect to the width, specifically a roll A film that is long enough to be rolled up into a shape and stored or transported.
  • the upper limit of the length of the film is not particularly limited, and can be, for example, 100,000 times or less the width.
  • the slow axis of a film or layer means the slow axis in the plane of the film or layer, unless otherwise specified.
  • the angle formed by the optical axes (slow axis, transmission axis, absorption axis, etc.) of each layer in a member including a plurality of layers is the angle when the layer is viewed from the thickness direction.
  • the oblique direction of a long film indicates the in-plane direction of the film, which is neither parallel nor perpendicular to the longitudinal direction of the film.
  • a material with positive intrinsic birefringence means a material whose refractive index in the stretching direction is greater than that in the direction perpendicular to it.
  • a material with 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 it.
  • the intrinsic birefringence value can be calculated from the dielectric constant distribution.
  • the NZ factor of a layer is a value expressed as (nx-nz)/(nx-ny) unless otherwise stated.
  • nx represents the refractive index in the direction (in-plane direction) perpendicular to the thickness direction of the layer, which gives the maximum refractive index.
  • ny represents the refractive index in the in-plane direction of the layer and in the direction orthogonal to the nx direction.
  • nz represents the refractive index in the thickness direction of the layer.
  • d represents the thickness of the layer.
  • the measurement wavelength is 590 nm unless otherwise stated.
  • the terms “parallel”, “perpendicular” and “perpendicular” in the directions of the elements are within a range that does not impair the effects of the present invention, such as ⁇ 3°, ⁇ 2° or ⁇ 1°, unless otherwise specified. may contain an error within the range of
  • An optical film according to one embodiment of the present invention comprises a layer (A) made of a resin (a) containing a crystalline polymer, and an amorphous layer provided on the main surface of the layer (A). and one or more layers (B) comprising a resin (b) containing a polymer having a Moreover, in the optical film according to the present embodiment, the NZ coefficient Nz is less than 1, and the plane orientation coefficient P of the layer (B) is 0.001 or less. Since the optical film of the present embodiment has the above structure, it can be an optical film having good adhesion to other resin layers such as a polarizer and a hard coat layer.
  • FIG. 1 is a cross-sectional view schematically showing an optical film according to one embodiment of the invention.
  • the optical film 100 includes a layer 110 as the layer (A), a layer 121 as the first layer (B), and a layer 122 as the second layer (B).
  • Layer 110 has two major surfaces, surface 110U and surface 110D.
  • a layer 121 is provided on the surface 110U, which is one main surface of the layer 110 . No other layer is interposed between the layers 110 and 121, and the layers 110 and 121 are directly in contact with each other.
  • a layer 122 is provided on the surface 110D that is the other main surface of the layer 110 . No other layer is interposed between layers 110 and 122, and layers 110 and 122 are directly in contact.
  • a layer 110 as a layer (A) is arranged between a layer 121 as a first layer (B) and a layer 122 as a second layer (B).
  • the optical film 100 has two layers (B), but in another embodiment, the optical film has only one layer (B), and the layer (A) is the layer 110,
  • the layer (B) may include the layer 121 and not include the layer 122 .
  • the optical film has two layers (B) as in the present embodiment.
  • the layer (A) is made of a resin (a) containing a crystalline polymer and is formed from the resin (a).
  • a "polymer having crystallinity” means a polymer having a melting point Tm. That is, a "polymer having crystallinity” means a polymer whose melting point can be observed with a differential scanning calorimeter (DSC).
  • DSC differential scanning calorimeter
  • a polymer having crystallinity may be referred to as a "crystalline polymer”.
  • a resin containing a crystalline polymer is sometimes referred to as a "crystalline resin”. This crystalline resin is preferably a thermoplastic resin.
  • the resin (a) preferably has a positive intrinsic birefringence.
  • an optical film having a NZ coefficient of less than 1.0 can be easily produced.
  • crystalline polymers examples include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylene (PE) and polypropylene (PP); It preferably contains formula structures.
  • PET polyethylene terephthalate
  • PEN polyethylene naphthalate
  • PE polyethylene
  • PP polypropylene
  • a polymer containing an alicyclic structure means a polymer having an alicyclic structure in its molecule.
  • a polymer containing such an alicyclic structure can be, for example, a polymer obtainable by a polymerization reaction using a cyclic olefin as a monomer or a hydride thereof.
  • Alicyclic structures include, for example, cycloalkane structures and cycloalkene structures. Among these, a cycloalkane structure is preferable because an optical film having excellent properties such as thermal stability can be easily obtained.
  • 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. be. 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 structural units having an alicyclic structure to all structural units is preferably 30% by weight or more, more preferably 50% by weight or more, and particularly preferably 70% by weight. % or more. Heat resistance can be improved by increasing the ratio of structural units having an alicyclic structure as described above.
  • the ratio of structural units having an alicyclic structure to all structural units can be 100% by weight or less.
  • the remainder other than the structural unit having an alicyclic structure is not particularly limited and can be appropriately selected according to 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 an optical film having excellent heat resistance can be easily obtained.
  • Polymer ( ⁇ ) A crystalline addition polymer of cyclic olefin monomers.
  • Polymer ( ⁇ ) A hydride of polymer ( ⁇ ) having crystallinity.
  • the crystalline polymer containing an alicyclic structure includes a ring-opening polymer of dicyclopentadiene having crystallinity, and a hydride of a ring-opening polymer of dicyclopentadiene. It is more preferable to have crystallinity. Among them, a hydrogenated ring-opening polymer of dicyclopentadiene having crystallinity is particularly preferable.
  • the ring-opening polymer of dicyclopentadiene means that the ratio of structural units derived from dicyclopentadiene to all 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 100% by weight of polymer.
  • the hydride of the ring-opening polymer of dicyclopentadiene preferably has a high ratio of racemo dyads.
  • the ratio of the racemo diad of repeating units in the hydrogenated 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 racemo dyads indicates high syndiotactic stereoregularity. Therefore, the melting point of the hydride of the ring-opening polymer of dicyclopentadiene tends to be higher as the ratio of the racemo diad is higher.
  • the ratio of racemo dyads can be determined based on the 13 C-NMR spectrum analysis described in the Examples below.
  • polymers ( ⁇ ) to polymer ( ⁇ ) polymers 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.
  • a crystalline polymer usually has a glass transition temperature Tg.
  • Tg glass transition temperature
  • the specific glass transition temperature Tg of the crystalline polymer is not particularly limited, it is usually 85°C or higher and usually 170°C or lower.
  • the glass transition temperature Tg, melting point Tm, and cold crystallization temperature Tc of the polymer and the crystalline resin and amorphous resin described later can be measured by the following methods. First, a polymer or resin is melted by heating, and the melted polymer or resin is rapidly cooled with dry ice. Subsequently, using this polymer or resin as a test sample, a differential scanning calorimeter (DSC) is used to measure the glass transition temperature of the polymer or resin at a heating rate of 10 ° C./min (heating mode). Tg, melting point Tm, and cold crystallization temperature Tc can be measured. The cold crystallization temperature Tc can be taken as the peak top value of the exothermic peak in the heating process.
  • DSC differential scanning calorimeter
  • the weight average molecular weight (Mw) of the crystalline polymer is preferably 1,000 or more, more preferably 2,000 or more, and preferably 1,000,000 or less, more preferably 500,000 or less.
  • a crystalline polymer having such a weight-average molecular weight has an excellent balance between moldability 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, and preferably 4.0 or less, more preferably 3.5 or less.
  • Mn represents the number average molecular weight.
  • a crystalline polymer having such a molecular weight distribution is excellent in moldability.
  • 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 degree of crystallinity of the crystalline polymer contained in the layer (A) is not particularly limited, but is usually higher than a certain level.
  • a specific crystallinity range is preferably 10% or higher, more preferably 15% or higher, and particularly preferably 30% or higher.
  • the crystallinity of a crystalline polymer can be measured by X-ray diffractometry.
  • the high degree of crystallinity of the crystalline polymer contained in the layer (A) of the optical film can be confirmed by the magnitude of the coefficient of thermal expansion of the optical film.
  • the coefficient of thermal expansion is a value measured under the following conditions.
  • a sample is obtained by cutting the optical film into a rectangular shape. This cutting is performed so that the longitudinal direction of the rectangular sample coincides with the MD direction (the longitudinal direction of the long film) or the TD direction (the width direction of the long film) of the film.
  • the linear expansion ⁇ L from 20° C. to 130° C. is measured at a heating rate of 10° C./min while applying a tension of 50 mN in the longitudinal direction of the obtained sample.
  • the value of the measured linear expansion ⁇ L is divided by the original length (that is, the length L before linear expansion), and the coefficient of thermal expansion (ppm) in the MD and TD directions is obtained according to the following formula, and the average value is
  • the coefficient of thermal expansion of the optical film is R TMA (ppm).
  • Thermal expansion coefficient (ppm) ( ⁇ L/L) x 1,000,000
  • the coefficient of thermal expansion RTMA of the optical film measured under the above conditions can serve as an index of the degree of crystallinity of the crystalline resin contained in the layer (A) of the optical film.
  • the coefficient of thermal expansion R TMA of the optical film is preferably 1200 ppm or less, more preferably 1000 ppm or less, still more preferably 800 ppm or less, particularly preferably 500 ppm or less, and usually 0 ppm or more.
  • the crystalline polymer may be used singly or in combination of two or more at any ratio.
  • the proportion of the crystalline polymer in the crystalline resin (a) is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more.
  • the proportion of the crystalline polymer is at least the lower limit of the above range, the birefringence and heat resistance of the optical film can be enhanced.
  • the upper limit of the proportion of crystalline polymer can be 100% by weight or less.
  • the crystalline resin (a) may contain any component in addition to the crystalline polymer.
  • Optional components include, for example, antioxidants such as phenol antioxidants, phosphorus antioxidants, and sulfur antioxidants; light stabilizers such as hindered amine light stabilizers; petroleum waxes, Fischer-Tropsch waxes, Waxes such as polyalkylene waxes; nucleating agents such as sorbitol compounds, metal salts of organic phosphoric acid, metal salts of organic carboxylic acids, kaolin and talc; diaminostilbene derivatives, coumarin derivatives, azole derivatives (e.g., benzoxazole derivatives, Fluorescent whitening agents such as benzotriazole derivatives, benzimidazole derivatives, and benzothiazole derivatives), carbazole derivatives, pyridine derivatives, naphthalic acid derivatives, and imidazolone derivatives; benzophenone-based UV absorbers, salicylic acid-based UV absorbers, benzotri
  • the cold crystallization temperature Tca of the crystalline resin (a) is not particularly limited, but is preferably 110° C. or higher, more preferably 120° C. or higher, still more preferably 130° C. or higher, and preferably 190° C. or lower, more preferably It is 180° C. or lower, more preferably 170° C. or lower.
  • the cold crystallization temperature Tca of the crystalline resin (a) is equal to or higher than the lower limit of the above range, the durability of the layer (A) under high-temperature environments can be enhanced. Further, when the cold crystallization temperature Tca of the crystalline resin (a) is equal to or lower than the upper limit of the above range, the optical film including the layer (A) can be stretched smoothly.
  • the thickness of the layer (A) can be set as appropriate, and may be, for example, 10 ⁇ m to 70 ⁇ m, such as 20 ⁇ m to 60 ⁇ m.
  • the layer (B) is made of a resin (b) containing an amorphous polymer and is formed from the resin (b).
  • amorphous polymer refers to a polymer that does not have a melting point. That is, "a polymer having amorphous properties” refers to a polymer whose melting point cannot be observed with a differential scanning calorimeter (DSC).
  • DSC differential scanning calorimeter
  • a polymer having amorphous properties may be referred to as an "amorphous polymer”.
  • a resin containing an amorphous polymer is sometimes referred to as an "amorphous resin”. This amorphous resin is preferably a thermoplastic resin.
  • the resin (b) preferably has a positive intrinsic birefringence.
  • an optical film having a NZ coefficient of less than 1.0 can be easily produced.
  • amorphous polymer one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.
  • amorphous polymer an amorphous polymer containing an alicyclic structure is preferable.
  • amorphous polymer containing an alicyclic structure may be referred to as “amorphous alicyclic structure-containing polymer” as appropriate.
  • the structural unit of the polymer contains an alicyclic structure.
  • the amorphous alicyclic structure-containing polymer may have an alicyclic structure in its main chain or may have an alicyclic structure in its side chains. Among them, a polymer containing an alicyclic structure in its main chain is preferable from the viewpoint of mechanical strength and heat resistance.
  • Alicyclic structures include, for example, saturated alicyclic hydrocarbon (cycloalkane) structures, unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structures, and the like. Among them, from the viewpoint of mechanical strength and heat resistance, a cycloalkane structure and a cycloalkene structure are preferable, and a cycloalkane structure is particularly preferable.
  • the number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, and particularly preferably 4 or more per alicyclic structure. is 15 or less.
  • the number of carbon atoms constituting the alicyclic structure is the above number, the mechanical strength, heat resistance, and moldability of the resin containing the alicyclic structure-containing polymer are highly balanced.
  • the ratio of structural units having an alicyclic structure in the polymer containing an amorphous alicyclic structure may be appropriately selected depending on the purpose of use, preferably 55% by weight or more, more preferably 70% by weight or more, Particularly preferably, it is 90% by weight or more.
  • the ratio of structural units having an alicyclic structure in the amorphous alicyclic structure-containing polymer is within this range, the resin has good transparency and heat resistance.
  • Examples of the alicyclic structure-containing polymer include norbornene polymers, monocyclic cyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof. can be done. Among these, norbornene-based polymers are preferable due to their good transparency and moldability.
  • Examples of norbornene-based polymers and hydrides thereof include ring-opened polymers of monomers having a norbornene structure and hydrides thereof; addition polymers of monomers having a norbornene structure and hydrides thereof.
  • Examples of ring-opening polymers of monomers having a norbornene structure include ring-opening homopolymers of one type of monomer having a norbornene structure, and ring-opening of two or more types of monomers having a norbornene structure. Examples include copolymers, and ring-opening copolymers of monomers having a norbornene structure and any monomers copolymerizable therewith.
  • addition polymers of monomers having a norbornene structure include addition homopolymers of one type of monomer having a norbornene structure, and addition copolymers of two or more types of monomers having a norbornene structure. and addition copolymers of monomers having a norbornene structure and arbitrary monomers copolymerizable therewith.
  • these polymers include those disclosed in JP-A-2002-321302.
  • hydrides of ring-opening polymers of monomers having a norbornene structure are particularly preferred from the viewpoints of moldability, heat resistance, low hygroscopicity, dimensional stability and lightness.
  • Examples of monomers having a norbornene structure include bicyclo[2.2.1]hept-2-ene (common name: norbornene), tricyclo[4.3.0.1 2,5 ]deca-3,7 - diene (common name: dicyclopentadiene), tetracyclo[4.4.0.1 2,5 .
  • substituents include alkyl groups such as methyl group, ethyl group, propyl group and isopropyl group; alkylidene groups; alkenyl groups; polar groups; Polar groups include, for example, heteroatoms or atomic groups having heteroatoms. Heteroatoms include, for example, oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, halogen atoms and the like.
  • polar groups include halogen groups such as a fluoro group, a chloro group, a bromo group, and an iodine group; a carboxyl group; a carbonyloxycarbonyl group; an epoxy group; a hydroxy group; an oxy group; silyl group; amino group; nitrile group; sulfone group; cyano group; amide group;
  • the number of substituents may be one, or two or more.
  • the types of the two or more substituents may be the same or different.
  • the norbornene-based monomer preferably has a small amount of polar groups, and more preferably does not have a polar group.
  • the weight average molecular weight (Mw) of the amorphous polymer is preferably 10,000 or more, more preferably 15,000 or more, particularly preferably 20,000 or more, and preferably 100,000 or less, more preferably 80. ,000 or less, particularly preferably 50,000 or less. When the weight average molecular weight is within this range, the mechanical strength and moldability of the layer (B) are highly balanced.
  • the molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) of the amorphous polymer is preferably 1.2 or more, more preferably 1.5 or more, and particularly preferably 1.8 or more, It is preferably 4.0 or less, more preferably 3.5 or less, and particularly preferably 3.0 or less.
  • Mw weight average molecular weight
  • Mn number average molecular weight
  • the weight average molecular weight Mw and number average molecular weight Mn of the amorphous polymer can be measured in terms of polystyrene by gel permeation chromatography (hereinafter abbreviated as "GPC") using tetrahydrofuran as a solvent. .
  • GPC gel permeation chromatography
  • polyisoprene by GPC using cyclohexane as a solvent.
  • the amount of the amorphous polymer contained in the resin (b) is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, and still more preferably 100% by weight of the resin (b). is 80% to 100% by weight, more preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight. When the amount of the amorphous polymer is within the above range, the properties of the amorphous polymer can be effectively exhibited.
  • the resin (b) may contain any component in addition to the amorphous polymer.
  • optional components include the same as the examples of optional components that the resin (a) may contain.
  • One type of optional component may be used alone, or two or more types may be used in combination at any ratio.
  • the glass transition temperature Tgb of the resin (b) is preferably 90° C. or higher, more preferably 100° C. or higher, still more preferably 110° C. or higher, preferably 200° C. or lower, more preferably 190° C. or lower, further preferably 180° C. °C or less.
  • the glass transition temperature Tgb of the resin (b) is equal to or higher than the lower limit of the above range, the durability of the layer (B) under high temperature environments can be enhanced. Further, when the glass transition temperature Tgb of the resin (b) is equal to or lower than the upper limit of the above range, the optical film including the layer (B) can be stretched smoothly.
  • the cold crystallization temperature Tca of the crystalline resin (a) and the glass transition temperature Tgb of the amorphous resin (b) preferably satisfy the following formula. -60°C ⁇ Tgb-Tca ⁇ 10°C
  • the difference (Tgb-Tca) is preferably -60°C or higher, more preferably -35°C or higher, still more preferably -30°C or higher, and preferably 10°C or lower, more preferably 5°C or lower.
  • Tgb ⁇ Tca a layer having a plane orientation coefficient P of 0.001 or less by adjusting the temperature for stretching the optical film.
  • the plane orientation coefficient P of layer (B) is usually 0.001 or less.
  • each surface of the first layer (B) and the second layer (B) is usually 0.001 or less.
  • the plane orientation coefficient P of the layer (B) is preferably 0.00095 or less, more preferably 0.00090 or less, still more preferably 0.00085 or less, preferably 0.00001 or more, more preferably 0.0001 or more. , and more preferably 0.0003 or more.
  • the adhesion between the layer (A) and other resin layers such as a polarizer and a hard coat layer is improved. sell.
  • the reason for this is presumed as follows, but it does not limit the present invention. It is considered that the smaller the plane orientation coefficient P, the greater the entanglement of the molecular chains in the thickness direction of the layer (B). As a result, it is presumed that the force applied perpendicularly to the thickness direction (that is, parallel to the surface) is increased, so that the peel strength is increased and the adhesion is enhanced.
  • Examples of methods for setting the plane orientation coefficient P of the layer (B) within the above range include selecting an amorphous resin having a glass transition temperature within an appropriate range and adjusting the draw ratio of the film.
  • the plane orientation coefficient P tends to decrease by selecting an amorphous resin having a low glass transition temperature with respect to the stretching temperature and/or by lowering the stretching ratio.
  • the thickness of the layer (B) can be set as appropriate, and may be, for example, 0.1 ⁇ m to 2 ⁇ m, such as 0.15 ⁇ m to 1.5 ⁇ m.
  • the optical film may have any layer in addition to the layers (A) and (B).
  • the optical film may have a pressure-sensitive adhesive layer for bonding with another resin layer such as a polarizer, and a layer containing an anti-blocking agent.
  • the optical film generally has a NZ coefficient Nz of less than one.
  • NZ coefficient Nz of the optical film is less than 1, good adhesion to other resin layers such as a polarizer can be achieved.
  • the reason why the NZ coefficient Nz of the optical film is less than 1 makes it possible to improve the adhesion is as follows, although it does not limit the present invention.
  • the NZ coefficient Nz of the optical film is preferably 0.9 or less, more preferably 0.8 or less, still more preferably 0.7 or less, preferably 0.1 or more, more preferably 0.15 or more, and still more preferably is 0.2 or more.
  • the in-plane retardation Re of the optical film may be appropriately set according to the use of the optical film.
  • the optical film may have an in-plane retardation that can function as, for example, a ⁇ /4 wavelength plate, and the in-plane retardation of the optical film is preferably 100 nm or more, more preferably 105 nm or more. , more preferably 110 nm or more, preferably 300 nm or less, more preferably 290 nm or less, still more preferably 280 nm or less.
  • the thickness of the optical film is preferably 55 ⁇ m or less, more preferably 50 ⁇ m or less, still more preferably 45 ⁇ m or less, and preferably 20 ⁇ m or more, more preferably 25 ⁇ m or more.
  • the optical film preferably has high transparency.
  • the total light transmittance of the optical film is preferably 80% or higher, more preferably 85% or higher, and particularly preferably 88% or higher.
  • the total light transmittance of the optical film can be measured in the wavelength range of 400 nm to 700 nm using an ultraviolet/visible spectrometer.
  • Optical films can be manufactured by any method.
  • the optical film is produced by, for example, step (1) of preparing a base film made of the resin (a), and coating the resin (b) and the solvent on at least one of the two surfaces of the base film.
  • Step (1), step (2), and step (3) are usually performed in this order.
  • the method for producing an optical film may include optional steps in addition to steps (1) to (3). A method for manufacturing an optical film according to one embodiment will be described below.
  • Step (1) a base film made of the resin (a) containing the crystalline polymer is prepared.
  • the base film contains resin (a) and is formed from resin (a).
  • the resin (a) can be the same as the resin (a) contained in the layer (A) of the optical film.
  • the degree of crystallinity of the resin (a) contained in the base film is preferably small.
  • a specific crystallinity is preferably less than 10%, more preferably less than 5%, particularly preferably less than 3%.
  • the coefficient of thermal expansion R1 TMA of the base film can be an index of the degree of crystallinity of the crystalline resin contained in the base film. The higher the coefficient of thermal expansion R1 TMA of the base film, the lower the degree of crystallinity of the crystalline resin contained in the base film.
  • the coefficient of thermal expansion R1 TMA of the substrate film is preferably 1000 ppm or more, more preferably 1500 ppm or more, still more preferably 2000 ppm or more, and preferably 10000 ppm or less, more preferably 9000 ppm or less, still more preferably 8000 ppm or less.
  • the coefficient of thermal expansion R1 TMA of the base film is a value measured under the same conditions as the coefficient of thermal expansion R TMA of the optical film.
  • the base film preferably contains a small amount of organic solvent, and more preferably does not contain an organic solvent.
  • the ratio (solvent content) of the organic solvent contained in the base film to 100% by weight of the base film is preferably 1% or less, more preferably 0.5% or less, and particularly preferably 0.1% or less. Yes, ideally 0.0%. Since the amount of the organic solvent contained in the base film is small, many molecules of the crystalline polymer can be oriented in the thickness direction in step (2), so the NZ coefficient of the optical film can be adjusted in a wide range.
  • the solvent content of the base film can be measured by density.
  • the base film may be a sheet-fed film, but it is preferably a long film.
  • a long base film By using a long base film, it is possible to continuously manufacture an optical film, so that the productivity of the optical film can be effectively improved.
  • the base film is preferably a film having optical isotropy. That is, the base film is preferably a film having a small birefringence (Re/d) in the in-plane direction and a small absolute value
  • Having optical isotropy means that the molecular orientation of the crystalline polymer contained in the base film is low and the film is in a substantially non-oriented state.
  • Re/d birefringence
  • the base film can be a film manufactured by any manufacturing method.
  • a method for producing the base film since a base film containing no organic solvent can be obtained, injection molding, extrusion molding, press molding, inflation molding, blow molding, calender molding, and cast molding are used.
  • a resin molding method such as a method, a compression molding method, or the like is preferable. Among these methods, the extrusion method is preferable because the thickness can be easily controlled.
  • the manufacturing conditions in the extrusion molding method are preferably as follows.
  • the cylinder temperature (molten resin temperature) is preferably Tm or higher, more preferably “Tm + 20°C” or higher, preferably “Tm + 100°C” or lower, more preferably “Tm + 50°C” or lower.
  • the cooling body with which the extruded molten resin in the form of a film first comes into contact 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, 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, and preferably “Tg+60°C” or lower, more preferably “Tg+30°C” or lower.
  • Tm represents the melting point of the crystalline polymer contained in the resin (a)
  • Tg represents the glass transition temperature of the crystalline polymer contained in the resin (a).
  • the in-plane retardation Re1 of the substrate film is preferably 10 nm or less, more preferably 8 nm or less, still more preferably 5 nm or less, and is usually 0 nm or more, may be 0 nm, or may be 1 nm or more. .
  • of the retardation Rth1 in the thickness direction of the base film is preferably 15 nm or less, more preferably 10 nm or less, still more preferably 8 nm or less, and is usually 0 nm or more, and may be 0 nm. It may be 1 nm or more.
  • the thickness d1 of the base film is preferably 8 ⁇ m or more, more preferably 10 ⁇ m or more, still more preferably 20 ⁇ m or more, and preferably 55 ⁇ m or less, more preferably 50 ⁇ m or less, still more preferably 45 ⁇ m or less.
  • the resulting optical film can be made thinner.
  • Step (2) In the step (2), a resin solution containing the resin (b) and a solvent is applied to at least one of the two surfaces of the base film to form a coating layer, thereby forming a laminated film. obtain.
  • the step (2) can usually change the birefringence in the thickness direction of the base film to obtain the layer (A) from the base film. Further, by forming a coating layer by coating a resin solution on the surface of a substrate film, an optical film in which the layer (A) and the layer (B) are directly attached can be produced.
  • the solvent contained in the resin solution is usually an organic solvent.
  • the organic solvent include a solvent that hardly dissolves the crystalline polymer contained in the base film, but can penetrate into the base film and dissolve the resin (b).
  • One type of organic solvent may be used, or two or more types may be used.
  • organic solvents examples include hydrocarbon solvents such as cyclohexane, toluene, limonene, and decalin; carbon disulfide; and mixed solvents thereof.
  • the organic solvent is preferably a mixed solvent of a solvent capable of dissolving the amorphous resin (b) and a solvent capable of penetrating the base film containing the crystalline resin (a).
  • a solvent capable of dissolving the amorphous resin (b) contains a crystalline polymer containing an alicyclic structure
  • examples of solvents capable of dissolving the amorphous resin (b) include cyclohexane, decalin, tetralin, and tetrachloride. carbon.
  • examples of solvents that can penetrate into the substrate film containing the crystalline resin (a) include toluene, xylene, and tetrahydrofuran. is mentioned.
  • the solvent contained in the resin solution is a mixed solvent of cyclohexane and toluene.
  • the weight ratio of cyclohexane/toluene in the organic solvent can be, for example, 4/6 to 9/1, such as 5/5 to 8/2.
  • the organic solvent comes into contact with the surface of the base film.
  • the birefringence in the thickness direction of the base film changes, and the layer (A) is formed from the base film.
  • the reason why the layer (A) is formed by changing the birefringence in the thickness direction of the base film by bringing the organic solvent into contact with the surface of the base film is presumed as follows. is not limited to
  • step (2) When the base film formed of the crystalline resin (a) is brought into contact with an organic solvent in step (2), the organic solvent penetrates into the base film. Micro-Brownian motion occurs in the molecules of the crystalline polymer in the film due to the action of the intruded organic solvent, and the molecular chains of the film are oriented.
  • the surface area of the base film is large on the front side and the back side, which are the main surfaces. Therefore, as for the penetration rate of the organic solvent, the penetration rate in the thickness direction through the front surface or the back surface is high. Then, the orientation of the molecules of the crystalline polymer can proceed such that the molecules of the polymer are oriented in the thickness direction.
  • the birefringence in the thickness direction of the base film changes. Therefore, through the step (2), it is possible to obtain the layer (A) in which the birefringence in the thickness direction is changed from the base film.
  • the resin solution may be applied only on one of the two surfaces of the base film to form a coating layer, and the resin solution may be applied on the two surfaces. Coating may be performed to form coating layers on both sides of the base film.
  • a method that can control the thickness of the coating layer formed on the surface of the substrate film by coating is preferably used.
  • coating methods include a wire bar coating method, a spray method, a roll coating method, a gravure coating method, a die coating method, a curtain coating method, a slide coating method, and an extrusion coating method. is preferred.
  • the thickness of the coating layer formed in step (2) is the thickness immediately after coating.
  • the thickness of the coating layer can be adjusted, for example, by adjusting the settings of the coating device (eg, the type of wire bar, the flow rate of the resin solution from the coating device, the conveying speed of the base film).
  • the thickness of the coating layer is preferably 3 ⁇ m or more, more preferably 5 ⁇ m or more, and preferably 30 ⁇ m or less, more preferably 25 ⁇ m or less, and even more preferably 20 ⁇ m or less.
  • the thickness of the coating layer means the thickness of one of the two formed coating layers when the coating layers are formed on both sides of the substrate film.
  • the concentration of the resin (b) in the resin solution is preferably a concentration at which the resin (b) does not precipitate, and is preferably 2% by weight or more, more preferably 4% by weight or more, based on 100% by weight of the resin solution, It is preferably 15% by weight or less, more preferably 10% by weight or less.
  • the temperature of the resin solution to be applied is arbitrary within the range below the boiling point of the solvent contained in the resin solution, preferably at a temperature at which the resin (b) can be dissolved in the organic solvent.
  • step (3) the laminated film obtained in step (2) is dried to obtain the layer (B) from the coating layer, and from the base film, the birefringence in the thickness direction changes.
  • the layer (A) thus formed is obtained.
  • step (3) a dried laminated film including layer (A) and layer (B) can be obtained.
  • the layer (B) By drying the laminated film, the layer (B) can be obtained by removing the solvent from the coating layer contained in the laminated film. Further, as described above, in step (2), the birefringence in the thickness direction of the base film can change. A modified layer (A) can be obtained.
  • drying method Any method can be adopted as the drying method depending on the boiling point of the solvent used.
  • drying methods include natural drying, drying by heating, drying under reduced pressure, and drying by heating under reduced pressure.
  • of the difference between the birefringence Rtha/da in the thickness direction of the layer (A) and the birefringence Rth1/d1 in the thickness direction of the base film is preferably 0.001 or more. , more preferably 0.002 or more, preferably 0.006 or less, more preferably 0.005 or less.
  • the dried laminated film obtained in step (3) has desired optical properties
  • the dried laminated film can be obtained as an optical film.
  • the method for producing an optical film may include optional steps in addition to the steps (1) to (3).
  • An example of the optional step includes a step (4) of stretching the dried laminate film after the step (3). By stretching, the molecules of the crystalline polymer contained in the laminated film can be oriented in a direction corresponding to the stretching direction. Therefore, the in-plane retardation, the retardation in the thickness direction, and the NZ coefficient of the obtained optical film can be adjusted.
  • the stretching direction there are no restrictions on the stretching direction, and examples thereof include the longitudinal direction, the width direction, and the oblique direction.
  • the oblique direction means a direction perpendicular to the thickness direction and neither parallel nor perpendicular to the width direction.
  • the stretching direction may be one direction or two or more directions.
  • the stretching method for example, a method of uniaxially stretching the laminated film in the longitudinal direction (longitudinal uniaxial stretching method), a method of uniaxially stretching the laminated film in the width direction (horizontal uniaxial stretching method), etc., uniaxial stretching method; Biaxial stretching methods such as a simultaneous biaxial stretching method in which the film is stretched in the longitudinal direction and the width direction at the same time, and a sequential biaxial stretching method in which the laminated film is stretched in one of the longitudinal direction and the width direction and then stretched in the other direction. a method of stretching the laminated film in an oblique direction (diagonal stretching method); and the like.
  • Another example of the uniaxial stretching method includes a fixed uniaxial stretching method in which the edges of the laminated film are fixed, and a free uniaxial stretching method in which the edges of the laminated film are not fixed.
  • the draw ratio is preferably 1-fold or more, more preferably 1.01-fold or more, and preferably 1.5-fold or less, more preferably 1.4-fold or less.
  • a specific draw ratio is desirably set appropriately according to factors such as the optical properties, thickness and strength of the laminated film to be drawn.
  • the draw ratio is equal to or higher than the lower limit of the above range, the birefringence can be greatly changed by drawing.
  • the draw ratio is equal to or less than the upper limit of the above range, the direction of the slow axis can be easily controlled, and breakage of the laminated film can be effectively suppressed.
  • the stretching temperature is preferably "Tg + 5°C” or higher, more preferably “Tg + 10°C” or higher, preferably “Tg + 100°C” or lower, more preferably “Tg + 90°C” or lower.
  • Tg represents the glass transition temperature of the crystalline polymer.
  • the stretching temperature is equal to or higher than the lower limit of the above range, the laminated film can be sufficiently softened and stretched uniformly. Further, when the stretching temperature is equal to or lower than the upper limit of the above range, it is possible to suppress the hardening of the laminated film due to the progress of crystallization of the crystalline polymer, so that the stretching can be smoothly carried out, and the birefringence is increased by stretching. can be expressed. Furthermore, usually, the haze of the optical film obtained after stretching can be reduced to increase the transparency.
  • Step (4) may further include any of the following steps in addition to the step of stretching the laminated film (referred to as step (4b)).
  • Step (4a) A step of preheating the laminated film.
  • Step (4c) A step of heat-treating the laminated film.
  • Step (4d) a step of cooling the laminated film.
  • step (4) includes step (4a)
  • step (4a) is usually performed before step (4b).
  • step (4c) is usually performed after step (4b).
  • step (4d) is usually performed after steps (4a) to (4c).
  • step (4c) can improve the heat resistance of the optical film.
  • the heat treatment temperature is usually higher than the glass transition temperature Tg of the crystalline polymer and lower than the melting point Tm of the crystalline polymer. More specifically, the heat treatment temperature is preferably Tg° C. or higher, more preferably Tg+10° C. or higher, and preferably Tm ⁇ 20° C. or lower, more preferably Tm ⁇ 40° C. or lower. Within the above temperature range, crystallization of the crystalline polymer can be rapidly progressed while suppressing white turbidity due to progress of crystallization.
  • the treatment time of heat treatment is preferably 1 second or longer, more preferably 5 seconds or longer, and preferably 30 minutes or shorter, more preferably 15 minutes or shorter.
  • the preheating temperature in step (4a) is usually the same as the stretching temperature in step (4b), but may be different.
  • the preheating temperature is preferably T1-10° C. or higher, more preferably T1-5° C. or higher, and preferably T1+5° C. or lower, more preferably T1+2° C. or lower, relative to the stretching temperature T1.
  • the preheating time is arbitrary, preferably 1 second or more, more preferably 5 seconds or more, and preferably 60 seconds or less, more preferably 30 seconds or less.
  • the cooling temperature in step (4d) is set lower than the heating temperature in the step prior to step (4d).
  • the cooling time is arbitrary, preferably 1 second or longer, more preferably 5 seconds or longer, and preferably 30 seconds or shorter, more preferably 20 seconds or shorter.
  • the optical film after step (4) may contain residual stress. Therefore, the method for producing an optical film may include, for example, a step of performing a relaxation treatment in which the stretched film is thermally shrunk to remove the residual stress. Relaxation treatment can remove residual stress by causing the film to thermally shrink in a suitable temperature range, usually while keeping the stretched film flat.
  • a long optical film can be produced by using a long base film.
  • the method for producing an optical film may include a step of winding the thus produced long optical film into a roll. Furthermore, the method for producing an optical film may include a step of cutting out a long optical film into a desired shape.
  • optical film of the present embodiment Since the optical film of the present embodiment has good adhesion to other resin layers such as a polarizer, it can be suitably used, for example, as a highly durable polarizing film in combination with a polarizer.
  • the polarizing film can be provided in a display device.
  • An optical film can improve display quality such as viewing angle, contrast, and image quality of an image displayed on a display device.
  • a polarizing film according to one embodiment of the present invention includes the optical film and a polarizer.
  • the optical film may contain only one layer (B), or may contain a first layer (B) and a second layer (B) as two layers (B).
  • the polarizing film has one layer (B) arranged between the layer (A) and the polarizer.
  • FIG. 2 is a cross-sectional view schematically showing a polarizing film according to one embodiment of the invention.
  • Polarizing film 200 includes polarizer 230, layer 210 as layer (A), layer 221 as first layer (B), and layer 222 as second layer (B).
  • the optical film is composed of layers 210 , 221 and 222 .
  • Layer 210 has two major surfaces, surface 210U and surface 210D.
  • a layer 221 is provided on a surface 210U that is one main surface of the layer 210 . No other layer is interposed between the layers 210 and 221, and the layers 210 and 221 are directly in contact with each other.
  • a layer 222 is provided on the surface 210D that is the other main surface of the layer 210 . No other layer is interposed between layers 210 and 222, and layers 210 and 222 are directly in contact.
  • a layer 210 as a layer (A) is arranged between a layer 221 as a first layer (B) and a layer 222 as a second layer (B).
  • a layer 221 as a first layer (B) is arranged between the layer 210 as the layer (A) included in the polarizing film 200 and the polarizer 230 .
  • a polarizer 230 is provided directly on the surface 221U of the layer 221.
  • polarizer 230 may be provided on surface 221U of layer 221 via an adhesive layer such as a layer of pressure sensitive adhesive.
  • the layer 222 is provided as the second layer (B) in this embodiment, the layer 222 may not be provided in another embodiment.
  • the layer 210 as layer (A) has the same configuration as the layer 110 included in the optical film 100 .
  • the layer 221 as the first layer (B) and the layer 222 as the second layer (B) have the same configurations as the layers 121 and 122 of the optical film 100, respectively.
  • any polarizer can be used as the polarizer 230 .
  • polarizers include linear polarizers.
  • linear polarizers include a film obtained by adsorbing iodine or a dichroic dye onto a polyvinyl alcohol film and then uniaxially stretching the film in a boric acid bath;
  • a polarizer containing polyvinyl alcohol is preferable as the linear polarizer.
  • the thickness of the linear polarizer can be, for example, 5 ⁇ m to 80 ⁇ m.
  • the angle formed by the in-plane slow axis of the optical film and the transmission axis of the linear polarizer should be in a specific range close to 45° when viewed from the thickness direction of the polarizing film. is preferred. Specifically, the angle is preferably 40° or more, more preferably 42° or more, still more preferably 43° or more, particularly preferably 44° or more, preferably 50° or less, more preferably 48°. Below, more preferably 47° or less, particularly preferably 46° or less.
  • the polarizing film may further contain any layer.
  • Optional layers include, for example, a polarizer protective film layer; an adhesive layer for laminating a polarizer and an optical film; a hard coat layer; a matte layer that improves the slipperiness of the polarizing film; antistatic layer; and the like. As for these optional layers, only one layer may be provided, or two or more layers may be provided.
  • the polarizing film can be produced by any method.
  • a polarizing film can be produced by laminating an optical film and a polarizer.
  • the optical film can be produced by a method including steps (1) to (3) described above.
  • Appropriate adhesives may be used for lamination.
  • a long polarizing film can be efficiently produced by laminating a long optical film and a long polarizer by a roll-to-roll method.
  • the glass transition temperature Tg, cold crystallization temperature Tc, and melting point Tm of the polymer or resin were measured as follows. First, a sample to be measured was melted by heating, and the melted sample was rapidly cooled with dry ice. Subsequently, using this sample as a test piece, a differential scanning calorimeter (DSC) was used to measure the glass transition temperature Tg and cold crystallization temperature Tc of the sample at a heating rate (heating mode) of 10 ° C./min. , and the melting point Tm were measured. The cold crystallization temperature Tc was taken as the peak top value of the exothermic peak during the heating process.
  • DSC differential scanning calorimeter
  • the resin to be confirmed was molded using a hot-melt extrusion film molding machine equipped with a T-die to obtain a long resin film (thickness: 39 ⁇ m) with a width of about 400 mm.
  • the resulting resin film was cut into pieces of 50 mm ⁇ 150 mm to obtain film pieces.
  • a tensile tester with a constant temperature and humidity chamber (“5564 model" manufactured by Instron) was used as a measuring device, and the film piece was freely uniaxially stretched.
  • the stretching temperature was (Tg+15° C. of the resin forming the film), and the pulling speed was 1.5 times/min.
  • the slow axis direction of the stretched film piece is determined by "AxoScan OPMF-1" manufactured by AXOMETRICS, and when the stretching direction and the slow axis direction are parallel, the intrinsic birefringence of the resin constituting the film piece is positive, and the intrinsic birefringence of the resin constituting the film piece is negative when the stretching direction and the slow axis direction are perpendicular to each other.
  • the thickness of the film was measured using a contact thickness gauge (Code No. 543-390 manufactured by MITUTOYO).
  • a layer (A) sample for measurement was prepared by the following method. - While wetting the surface of the laminated film with water, sandpaper (#4000, #8000, #15000) was used in order to scrape off layer (B) on the surface of the film to thin the film, leaving only layer (A). When the layer (B) did not adhere to the layer (A), a layer (B) sample for measurement was prepared by the following method. - A cellophane tape was attached to the surface of the laminated film and then peeled off to remove the layer (B) from the laminated film.
  • the retardation Rth in the thickness direction was measured for the obtained layer (A) sample.
  • the measurement was performed by "AxoScan OPMF-1" manufactured by AXOMETRICS. Measurements were made at a wavelength of 590 nm. By the method described above, the thickness of the layer (A) sample was measured to determine the Rth/d of the layer (A).
  • Method for measuring thermal expansion coefficient RTMA of film A sample was obtained by cutting the film into a strip (rectangular shape) of 5 mm ⁇ 20 mm. This cutting was performed so that the longitudinal direction of the strip-shaped sample coincided with the MD direction (the longitudinal direction of the long film) or the TD direction (the width direction of the long film) of the film. Linear expansion was measured from 20° C. to 130° C. at a heating rate of 10° C./min while applying a tension of 50 mN in the longitudinal direction of the sample. The measurement was performed using a thermomechanical analyzer (“TMA/SS7100” manufactured by SSI Nanotechnology). The measured linear expansion value is divided by the original length (that is, the length before linear expansion) to obtain the coefficient of thermal expansion (ppm) in the MD and TD directions, and the average value is the coefficient of thermal expansion RTMA (ppm).
  • TMA/SS7100 thermomechanical analyzer
  • a solution was prepared by dissolving 0.014 parts of a tetrachlorotungstenphenylimide (tetrahydrofuran) complex in 0.70 parts of toluene. To this solution, 0.061 part of a 19% diethylaluminum ethoxide/n-hexane solution was added and stirred for 10 minutes to prepare a catalyst solution. This catalyst solution was added to the pressure reactor to initiate the ring-opening polymerization reaction. Thereafter, the mixture was allowed to react for 4 hours while maintaining the temperature at 53° C. to obtain a solution of a ring-opening polymer of dicyclopentadiene. The obtained ring-opening polymer of dicyclopentadiene had a number average molecular weight (Mn) and a weight average molecular weight (Mw) of 8,750 and 28,100, respectively. was 3.21.
  • Mn number average molecular weight
  • Mw weight average molecular weight
  • a filter aid ("Radiolite (registered trademark) #1500” manufactured by Showa Kagaku Kogyo Co., Ltd.) is added, and a PP pleated cartridge filter (“TCP-HX” manufactured by ADVANTEC Toyo Co., Ltd.) is used as an adsorbent.
  • TCP-HX PP pleated cartridge filter
  • the hydride contained in the reaction solution and the solution were separated using a centrifugal separator and dried under reduced pressure at 60° C. for 24 hours to obtain a crystalline hydride of a ring-opening polymer of dicyclopentadiene 28. 5 copies were obtained.
  • This hydride had a hydrogenation rate of 99% or more, a glass transition temperature Tg of 93° C., a melting point (Tm) of 267° C., and a ratio of racemo diad of 89%.
  • An antioxidant tetrakis[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane was added to 100 parts of the hydride of the resulting ring-opening polymer of dicyclopentadiene. ; After mixing 1.1 parts of "Irganox (registered trademark) 1010" manufactured by BASF Japan Co., Ltd., a twin-screw extruder equipped with four die holes with an inner diameter of 3 mm ⁇ (product name "TEM-37B", manufactured by Toshiba Machine Co., Ltd. ).
  • a mixture of a hydride of a ring-opening polymer of dicyclopentadiene and an antioxidant is formed into a strand by hot-melt extrusion molding, and then chopped with a strand cutter to obtain a pellet-shaped crystalline resin (a-1 ).
  • the cold crystallization temperature Tca of the crystalline resin (a-1) was 137°C.
  • the reaction solution was filtered under pressure at a pressure of 0.25 MPa using Radiolite #500 as a filter bed ("Fundabak filter” manufactured by Ishikawajima-Harima Heavy Industries Co., Ltd.) to remove the hydrogenation catalyst and obtain a colorless and transparent solution. .
  • the resulting solution was poured into a large amount of isopropanol to precipitate a ring-opening polymer hydride of a norbornene-based monomer.
  • antioxidant penentaerythritol-tetrakis[3-(3,5-di-t-butyl-4 -Hydroxyphenyl)propionate] (manufactured by Ciba Specialty Chemicals, product name: "Irganox (registered trademark) 1010"] was dissolved in 2.0 parts of a xylene solution. Then, it was dried in a vacuum dryer (200° C., 1 Torr) for 6 hours to obtain an amorphous resin (b-2) containing a thermoplastic norbornene polymer hydride. The weight average molecular weight of the hydrogenated norbornene polymer was 4.4 ⁇ 10 4 .
  • the glass transition temperature Tg of the amorphous resin (b-2) was measured by the method described above.
  • the glass transition temperature Tg of the amorphous resin (b-2) was 116°C.
  • the amorphous resin (b-2) obtained in the above process was put into a twin-screw extruder and molded into a strand-shaped body by hot-melt extrusion molding. This compact was cut into small pieces using a strand cutter to obtain pellets of the amorphous resin (b-2).
  • Step (1) Production of film made of crystalline resin (a))
  • the crystalline resin (a-1) produced in Production Example 1 was molded using a hot-melt extrusion film molding machine equipped with a T-die to obtain an extruded film (thickness: 39 ⁇ m) having a width of approximately 400 mm and serving as a base film. rice field.
  • the resulting extruded film was wound into roll form.
  • film (1) The resulting extruded film was used as a base film (film (1)).
  • the evaluation results of film (1) were as shown in the table below.
  • the transport direction (MD direction) during the production of the film (1) is the long side, A4 size (210 mm ⁇ 297 mm).
  • the prepared coating resin solution was applied.
  • the resulting coated film (film (2)) as the laminated film was dried at 100° C. for 2 minutes to form a layer of resin (b) as the first layer (B) from the coated layer.
  • the coating resin solution is applied to the other surface of the film (1) in the same manner, and the resulting coated film is dried at 100° C. for 2 minutes to remove the second film from the coating layer.
  • a layer of resin (b) was formed as layer (B).
  • the layer (A) is formed from the film (1) as the base film, and the first layer (B) is formed on one of the two main surfaces of the layer (A).
  • a second layer (B) was formed on the other main surface of the layer (A) to obtain a film (3) as a dried laminated film.
  • the evaluation results of film (3) were as shown in the table below.
  • Step (4) Stretching and heating step
  • the film (3) cut to a size of 100 mm ⁇ 100 mm is supplied to a stretching machine (manufactured by Eto Co., Ltd.), and the both ends of the film are held by five clips, and the film (1) (extruded film) is transported in the production direction.
  • the film (4) was produced as an optical film by free uniaxial stretching to 1.1 times.
  • the dried coating layer is irradiated with UV under the conditions of a peak illuminance of 320 mW/cm 2 and an integrated light intensity of 500 mJ/cm 2 to apply the coating.
  • the layer was cured.
  • the hard coat layer is formed from the coating layer, and the layer structure of (second layer (B)) / (layer (A)) / (first layer (B)) / (hard coat layer)
  • a film (5) having The film (5) was evaluated for adhesion by the method described above. The evaluation results are shown in the table below.
  • Example 2 A film (4) was obtained in the same manner as (1-1) to (1-3) of Example 1, except that the following items were changed. - In (1-2) (preparation of resin solution), the amorphous resin (b-2) pellets produced in Production Example 2 were used instead of the amorphous resin (b-1) pellets. . (1-3. Step (4): Stretching and heating step), (4a): preheat the film (3) to 150 ° C., and then; (4b): heat the preheated film (3) to 150 (4c): The stretched film (3) was held under tension at a temperature of 150°C to promote crystallization, and (4d): crystallization was promoted. cooling the film (3) at a temperature of 100°C;
  • a polarizing film as a polarizer was prepared by a method similar to that described in Example 1 of JP-A-2005-70140. ) was prepared.
  • the film (5) has a layer structure of (second layer (B))/(layer (A))/(first layer (B))/(adhesive layer)/(polarizing film). The film (5) was evaluated for adhesion by the method described above.
  • Example 3 A film (4) was obtained in the same manner as in (1-1) to (1-3) of Example 1, except that the following items were changed. - In (1-2) (preparation of resin solution), instead of the amorphous resin (b-1) pellets, an amorphous resin (b-3) containing a polymer containing an alicyclic structure ( Pellets of "ZEONEX (registered trademark) 1020R" (manufactured by Zeon Corporation) were used. In (1-3.
  • Step (4) Stretching and heating step), stretching is performed by (4a): preheating the film (3) to 130 ° C., and then; (4b): preheating the film (3) to 130 (4c): The stretched film (3) was held under tension at a temperature of 130°C to promote crystallization, and (4d): crystallization was promoted. cooling the film (3) at a temperature of 100°C;
  • film (5) was obtained by the same operation as in Example 2 (bonding of film (4) and polarizing film). The film (5) was evaluated for adhesion by the method described above.
  • Example 4 A film (3) as an optical film was obtained in the same manner as in (1-1) and (1-2) of Example 1.
  • Example 2 Using the obtained film (3) instead of the film (4), the same operation as in (1-4) of Example 1 was performed to obtain (second layer (B)) / (layer (A)) A film (5) having a layer structure of /(first layer (B))/(hard coat layer) was obtained. The film (5) was evaluated for adhesion by the method described above.
  • Example 1 An extruded film was obtained in the same manner as in Example 1 (1-1). The extruded film was cut into a size of 100 mm ⁇ 100 mm and freely uniaxially stretched 1.1 times in the transport direction during production of the extruded film to prepare a film (1) having a thickness of 35 ⁇ m as a base film. (a) preheating the extruded film to 140°C, then; (b) stretching the preheated extruded film at 160°C to obtain a stretched film, and (c) stretching the stretched film. The stretched film was held at a temperature of 160°C to promote crystallization, and then;
  • a film (3) was obtained in the same manner as in Example 1 (1-2. Steps (2) and (3)), except that the following items were changed. -
  • the film (1) (stretched film) was used as the base film.
  • the resin solution for coating was applied so that the coating layer had a thickness of 32 ⁇ m (that is, the thickness after drying was about 1.6 ⁇ m).
  • a film (5) was obtained in the same manner as in Example 1 (1-4), except that the following items were changed. - Instead of the film (4) of Example 1, the obtained film (3) was used. The film (5) was evaluated for adhesion by the method described above.
  • One surface of the resulting film (1) was subjected to corona treatment (output 300 W, voltage 24.19 V, processing speed 80 mm/sec).
  • corona treatment output 300 W, voltage 24.19 V, processing speed 80 mm/sec.
  • "FA-3292" manufactured by Nippon Kako Toryo Co., Ltd.
  • the formed coating layer was dried in a drying oven at 100° C. for 30 seconds.
  • the dried coating layer is irradiated with UV under the conditions of a peak illuminance of 320 mW/cm 2 and an integrated light intensity of 500 mJ/cm 2 to apply the coating.
  • the layer was cured.
  • a hard coat layer was formed from the coating layer to obtain a film (5) having a layer structure of layer (A)/(hard coat layer).
  • the film (5) was evaluated for adhesion by the method described above.
  • a-1 represents the crystalline resin (a-1) produced in Production Example 1.
  • b-2 represents the amorphous resin (b-2) produced in Production Example 2.
  • 690R represents an amorphous resin (b-1) containing a polymer containing an alicyclic structure ("ZEONEX (registered trademark) 690R” (manufactured by Zeon Corporation)).
  • 1020R represents an amorphous resin (b-3) containing a polymer containing an alicyclic structure ("ZEONEX (registered trademark) 1020R” (manufactured by Zeon Corporation)).
  • Re1, Rth1, and d1 represent the in-plane retardation of film (1) (base film), the retardation in the thickness direction of film (1), and the thickness of film (1), respectively.
  • Rth1/d1 represents the birefringence in the thickness direction of the film (1).
  • Nz1 represents the NZ coefficient of film (1).
  • R1 TMA represents the coefficient of thermal expansion of film (1).
  • Rtha/da represents the birefringence in the thickness direction of the layer (A) included in the film (3).
  • Re3, Rth3, and d3 represent the in-plane retardation of film (3), the retardation in the thickness direction of film (3), and the thickness of film (3), respectively.
  • Nz3 represents the NZ coefficient of film (3).
  • Re4, Rth4, and d4" represent the in-plane retardation of film (4), the retardation in the thickness direction of film (4), and the thickness of film (4), respectively.
  • Nz4 represents the NZ coefficient of film (4).
  • the "plane orientation coefficient P" is the value measured for the layer (B) of the film (4) for Examples 1 to 3, and the value for the layer (B) of the film (3) for Example 4 and Comparative Example 1.
  • B) is the measured value.
  • "Thermal expansion coefficient R TMA" is the value measured for the film (4) for Examples 1 to 3, and the value measured for the film (3) for Example 4 and Comparative Example 1. , for Comparative Example 2, are the values measured for the film (1).
  • film (5) layer structure has the following meanings.
  • A represents layer (A).
  • B represents layer (B).
  • HC represents a hard coat layer.
  • AD stands for adhesive layer.
  • PO represents a layer of polarizer.
  • the optical film according to Comparative Example 2 which does not include the layer (B), is classified as Class 5 in the adhesion evaluation with the resin layer (hard coat layer), which is unsatisfactory.
  • the optical film according to Comparative Example 1 in which the NZ coefficient Nz3 of the optical film (film (3)) is 1 or more, has poor adhesion to the resin layer (hard coat layer), which is Class 5. .
  • the optical films of Examples 1 to 4 comprising a layer (A) and a layer (B), having an NZ coefficient of less than 1 and a plane orientation coefficient P of the layer (B) of 0.001 or less (implementation Examples 1 to 3: Film (4) and Example 4: Film (3)) are classified as 0 in adhesion to the resin layer (hard coat layer or polarizer) and are good.

Abstract

L'invention concerne un film optique comprenant une couche (A) comprenant une résine (a) renfermant un polymère cristallin et une ou plusieurs couches (B) disposées sur la(les) surface(s) principale(s) de la couche (A) et comprenant chacune une résine (b) renfermant un polymère amorphe. Le film optique a un coefficient NZ (Nz) inférieur à 1, et les couches (B) ont un coefficient d'orientation planaire P de 0,001 ou moins.
PCT/JP2022/001457 2021-01-29 2022-01-17 Film optique, son procédé de production et film polarisant WO2022163416A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2022578252A JPWO2022163416A1 (fr) 2021-01-29 2022-01-17

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021013463 2021-01-29
JP2021-013463 2021-01-29

Publications (1)

Publication Number Publication Date
WO2022163416A1 true WO2022163416A1 (fr) 2022-08-04

Family

ID=82653307

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/001457 WO2022163416A1 (fr) 2021-01-29 2022-01-17 Film optique, son procédé de production et film polarisant

Country Status (3)

Country Link
JP (1) JPWO2022163416A1 (fr)
TW (1) TW202248013A (fr)
WO (1) WO2022163416A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017115776A1 (fr) * 2015-12-28 2017-07-06 日本ゼオン株式会社 Corps optique stratifié, plaque de polarisation et dispositif d'affichage à cristaux liquides
WO2017115779A1 (fr) * 2015-12-28 2017-07-06 日本ゼオン株式会社 Corps optique stratifié ainsi que procédé de fabrication de celui-ci, plaque de polarisatio, et dispositif d'affichage
WO2020137409A1 (fr) * 2018-12-27 2020-07-02 日本ゼオン株式会社 Stratifié optiquement anisotrope, procédé de production de celui-ci, plaque de polarisation circulaire et dispositif d'affichage d'image
JP2020170072A (ja) * 2019-04-02 2020-10-15 日東電工株式会社 位相差フィルム、偏光板および画像表示装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017115776A1 (fr) * 2015-12-28 2017-07-06 日本ゼオン株式会社 Corps optique stratifié, plaque de polarisation et dispositif d'affichage à cristaux liquides
WO2017115779A1 (fr) * 2015-12-28 2017-07-06 日本ゼオン株式会社 Corps optique stratifié ainsi que procédé de fabrication de celui-ci, plaque de polarisatio, et dispositif d'affichage
WO2020137409A1 (fr) * 2018-12-27 2020-07-02 日本ゼオン株式会社 Stratifié optiquement anisotrope, procédé de production de celui-ci, plaque de polarisation circulaire et dispositif d'affichage d'image
JP2020170072A (ja) * 2019-04-02 2020-10-15 日東電工株式会社 位相差フィルム、偏光板および画像表示装置

Also Published As

Publication number Publication date
JPWO2022163416A1 (fr) 2022-08-04
TW202248013A (zh) 2022-12-16

Similar Documents

Publication Publication Date Title
TWI715691B (zh) 圓偏光板及使用其之可撓性圖像顯示裝置
TWI680313B (zh) 多層膜、偏光板及多層膜的製造方法
JP2019061291A (ja) 偏光板
JP6930544B2 (ja) 多層フィルム、偏光板、及び液晶表示装置
JPWO2020175217A1 (ja) 樹脂フィルムの製造方法、並びに、位相差フィルム及びその製造方法
JP7140124B2 (ja) 光学フィルム及びその製造方法
WO2022163416A1 (fr) Film optique, son procédé de production et film polarisant
TWI749155B (zh) 光學薄膜、製造方法及多層薄膜
US20220251318A1 (en) Phase contrast film and production method therefor
WO2021153695A1 (fr) Procédé de fabrication de film de retard
WO2021107108A1 (fr) Film de contraste de phase et son procédé de production
WO2022145174A1 (fr) Film optique et son procédé de fabrication
WO2021039934A1 (fr) Film de déphasage, et procédé de fabrication de celui-ci
WO2023063129A1 (fr) Plaque de polarisation équipée d'une couche de retard et dispositif d'affichage d'image l'utilisant
WO2021261276A1 (fr) Lame polarisante, lame polarisante équipée d'une couche de retard et dispositif d'affichage d'image
JP7322889B2 (ja) 成形体及びその製造方法
JP4325317B2 (ja) 光学積層体、光学素子、液晶表示装置、及び光学積層体の製造方法
WO2022209818A1 (fr) Film optique et son procédé de fabrication
WO2016158275A1 (fr) Corps d'enroulement de film optique, procédé pour le stocker, et procédé de fabrication de film de base/complexe de plaque de polarisation
JP2022104366A (ja) 光学フィルム及びその製造方法
JP2023111233A (ja) 光学積層体および画像表示装置
JP2023111232A (ja) 光学積層体および画像表示装置
JP2022103573A (ja) 光学フィルム及びその製造方法、並びに延伸フィルムの製造方法
JP2024049134A (ja) 光学フィルムの製造方法
JP2023073124A (ja) 位相差層付偏光板および該位相差層付偏光板を含む画像表示装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22745639

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022578252

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22745639

Country of ref document: EP

Kind code of ref document: A1