JP2017142331A - Optical film, production method, polarizing plate and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an optical film and a production method thereof, the film having high mechanical strength and good optical characteristics such as a low retardation, having high durability against an organic solvent and suppressing occurrence of blocking, and being advantageously usable as a protective film in a polarizing plate; and a polarizing plate and a display device including the above optical film.SOLUTION: The optical film is made of a crosslinked product of an untreated film containing a hydrogenated block copolymer. The hydrogenated block copolymer is obtained by hydrogenating a specific block copolymer composed of two or more polymer blocks [A] essentially comprising a specific repeating unit [I] and at least one polymer block [B] essentially comprising a specific repeating unit [II] or a combination of the repeating unit [I] and the repeating unit [II]. The optical film has a specific tensile fraction elongation and a solvent-insoluble content percentage. A production method of the optical film, and a polarizing plate and a display device including the optical film are also disclosed.SELECTED DRAWING: None

Description

  The present invention relates to an optical film, a method for producing the same, and an application thereof, and more particularly to an optical film suitable for use as a polarizing plate protective film.

  A display device such as a liquid crystal display device is provided with various optical elements such as a polarizing plate and a retardation plate. Some of these optical elements are constituted by films. For example, the polarizing plate generally includes a film-like polarizer formed of a material such as polyvinyl alcohol and a protective film that protects the polarizer. As an example of such a protective film, a resin film containing an alicyclic structure-containing polymer is known (Patent Document 1). The resin film containing the alicyclic structure-containing polymer can be usefully used as a protective film in a polarizing plate from the viewpoint of mechanical strength and optical properties. In particular, it is known that a specific block copolymer is used as the alicyclic structure-containing polymer to obtain a polymer having particularly preferable optical characteristics as a protective film, such as a low retardation. 2).

JP 2007-245551 A JP 2011-013378 A

  The polarizing plate is required to exhibit durability in an environment during production and use of the display device. For example, it may be necessary to further provide a layer such as a hard coat layer on the surface of the polarizing plate, and in that case, a step of applying a solution containing an organic solvent to the surface of the polarizing plate may be performed. is there. At this time, if the protective film has low resistance to the organic solvent, the optical performance of the display device may be impaired.

  Moreover, a protective film and a polarizing plate may be manufactured in a long shape, and may be preserve | saved in the shape of a film roll. At this time, blocking (a phenomenon in which adjacent surfaces of the film adhere to each other in the film roll) may occur, thereby impairing the quality of the film.

  Accordingly, the object of the present invention is to provide a good optical property such as high mechanical strength and low retardation, and in addition, it has high resistance to an organic solvent and suppresses occurrence of blocking, and is useful as a protective film in a polarizing plate. Optical film and method for producing the same, polarizing plate having high mechanical strength and good optical properties, high resistance to organic solvents and suppressed occurrence of blocking, and high mechanical strength and The object is to provide a display device having good optical performance.

As a result of studying to solve the above-mentioned problems and achieving the object, the present inventors have found that the above-mentioned problems can be solved by applying a specific treatment to a specific copolymer film, and the present invention has been completed. I let you.
That is, according to the present invention, the following [1] to [8] are provided.

[1] An optical film comprising a cross-linked product of a pre-treatment film containing a block copolymer hydride [D],
The block copolymer hydride [D] is:
Two or more polymer blocks [A] based on a repeating unit [I] derived from a cyclic hydrocarbon group-containing compound;
A block copolymer consisting of a repeating unit [II] derived from a chain hydrocarbon compound, or one or more polymer blocks [B] having as a main component a combination of the repeating unit [I] and the repeating unit [II] Hydrogenate the union [C]:
(I) The ratio of wA to wB (wA / wB) is 50/50 to 75/25, where wA is the weight fraction of the polymer block [A] in the block copolymer [C]. WB is a weight fraction of the polymer block [B] in the block copolymer [C],
(Ii) The ratio of w [IB] to w [IIB] (w [IB] / w [IIB]) is 50/50 to 0/100, where w [IB] is the polymer block [B ] And the weight fraction of the repeating unit [I] in the polymer block [B], and w [IIB] is the weight fraction of the repeating unit [II] in the polymer block [B].
(Iii) The block copolymer hydride [D] is obtained by hydrogenating 90% or more of the total unsaturated bonds of the block copolymer [C],
The optical film is:
(Iv) The tensile elongation at break is 100% or more,
(V) An optical film having a solvent-insoluble component ratio of 85% or more.
[2] The optical film according to [1], wherein the cyclic hydrocarbon group-containing compound is an aromatic vinyl compound, and the chain hydrocarbon compound is a chain conjugated diene compound.
[3] The optical film according to [1] or [2], wherein the front phase difference Re is 5 nm or less.
[4] The optical film according to any one of [1] to [3], wherein the pre-treatment film containing the block copolymer hydride [D] is irradiated with an electron beam or γ-ray.
[5] The method for producing an optical film according to any one of [1] to [4],
The manufacturing method including the line irradiation process of irradiating an electron beam or a gamma ray to the film before a process containing block copolymer hydride [D].
[6] The production method according to [5], wherein an oxygen concentration in an atmosphere in which the line irradiation step is performed is smaller than 300 ppm.
[7] The production method according to [5] or [6], wherein a dose in the line irradiation step is 200 kGy or more and 800 kGy or less.
[8] A polarizing plate comprising the optical film according to any one of [1] to [4] and a polarizer.
[9] A display device comprising the optical film according to any one of [1] to [4].

  The optical film of the present invention has good mechanical properties such as high mechanical strength and low retardation, and in addition, has high resistance to organic solvents and suppresses occurrence of blocking, and is useful as a protective film in a polarizing plate. Can do. Moreover, according to the manufacturing method of the optical film of this invention, such an optical film can be manufactured easily. The polarizing plate of the present invention can have high mechanical strength and good optical properties, as well as high resistance to organic solvents and suppression of blocking. The display device of the present invention can be a display device with high mechanical strength and good optical performance.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and exemplifications, and can be implemented with arbitrary modifications without departing from the scope of the claims of the present invention and the equivalents thereof.

  In the present application, the “long” film refers to a film having a length of 5 times or more, preferably 10 times or more of the width of the film, specifically, It has a length enough to be wound up in a roll and stored or transported. Although the upper limit of the ratio of the length with respect to the width of a film is not specifically limited, For example, it can be 100,000 times or less.

[1. Optical Film and its Manufacturing Method: Overview]
The optical film of the present invention comprises a specific crosslinked film before processing.

[1.1. Material of film before processing
The pre-treatment film contains a specific block copolymer hydride [D]. The pre-treatment film can usually be made of a resin containing a block copolymer hydride [D].

[1.1.1. Block copolymer hydride [D]]
The block copolymer hydride [D] is formed by hydrogenating a specific block copolymer [C]. The block copolymer [C] is composed of two or more specific polymer blocks [A] per molecule and one or more specific polymer blocks [B] per molecule.

[1.1.1.1. Polymer block [A]]
The polymer block [A] contains a repeating unit [I] derived from a cyclic hydrocarbon group-containing compound as a main component. In the present application, a unit derived from a compound is a unit having a structure obtained by polymerization of the compound. The content of the repeating unit [I] in the polymer block [A] is preferably 98% by weight or more, more preferably 99% by weight or more. Examples of the repeating unit other than the repeating unit [I] of the polymer block [A] include a repeating unit [II] derived from a chain hydrocarbon compound and / or another vinyl compound (that is, a vinyl compound, and And a repeating unit [III] derived from a compound that is neither a cyclic hydrocarbon group-containing compound nor a chain hydrocarbon compound. The content is preferably 2% by weight or less, more preferably 1% by weight or less.

  By making the component of the repeating unit [II] and / or the repeating unit [III] derived from other vinyl compound in the polymer block [A] below the lower limit, the heat resistance of the optical film can be improved. . The two polymer blocks [A] contained in the block copolymer [C] may be the same as or different from each other as long as they satisfy the above range.

[1.1.1.2. Polymer block [B]]
The polymer block [B] has a repeating unit [II] derived from a chain hydrocarbon compound as a main component, or a combination of the repeating unit [I] and the repeating unit [II] as a main component. The ratio of the weight fraction w [IB] of the repeating unit [I] to the weight fraction w [IIB] of the repeating unit [II] in the polymer block [B], that is, w [IB] / w [IIB] is , Preferably 50/50 or less, more preferably 45/55 or less, even more preferably 40/60 or less, while preferably 0/100 or more, more preferably 5/95 or more, and even more preferably 10/90. That's it.

  The total content of the repeating unit [I] and the repeating unit [II] in the polymer block [B] is preferably 95% by weight or more, more preferably 97% by weight or more, and even more preferably 99% by weight or more. is there. Components other than the repeating unit [I] and the repeating unit [II] in the polymer block [B] include repeating units [III] derived from other vinyl compounds. The content is preferably 5% by weight or less, more preferably 3% by weight or less, and even more preferably 1% by weight or less.

  By making the content ratio of the repeating unit [I] and the repeating unit [II] in the polymer block [B] within the above range, the block copolymer hydride [D] and the mechanical strength of the optical film including the same are obtained. Flexibility can be improved, and heat resistance against a change in phase difference can be improved.

[1.1.1.3. Cyclic hydrocarbon group-containing compound]
In the present application, the “cyclic hydrocarbon group-containing compound” is a compound containing a cyclic hydrocarbon group such as an alicyclic hydrocarbon group or an aromatic group. The cyclic hydrocarbon group-containing compound also has a polymerizable group that can form the repeating unit [I] by a polymerization reaction. The cyclic hydrocarbon group-containing compound itself is a compound having an alicyclic structure, or becomes a compound having an alicyclic structure when hydrogenated.

  Preferable examples of the cyclic hydrocarbon group-containing compound include aromatic vinyl compounds. Examples of aromatic vinyl compounds include styrene; α-methyl styrene, 2-methyl styrene, 3-methyl styrene, 4-methyl styrene, 2,4-diisopropyl styrene, 2,4-dimethyl styrene, 4-t-butyl. Styrenes having a C1-C6 alkyl group as a substituent, such as styrene and 5-t-butyl-2-methylstyrene; As substituents such as 4-chlorostyrene, dichlorostyrene, 4-monofluorostyrene Styrenes having a halogen atom; styrenes having a C1-C6 alkoxy group as a substituent such as 4-methoxystyrene; styrenes having an aryl group as a substituent such as 4-phenylstyrene; 1-vinyl And vinyl naphthalenes such as naphthalene and 2-vinylnaphthalene. Among these, from the viewpoint of hygroscopicity, aromatic vinyl compounds that do not contain a polar group, such as styrene and styrenes having a C 1-6 alkyl group as a substituent, are preferable, because of industrial availability. Styrene is particularly preferred.

[1.1.1.4. (Chain hydrocarbon compound)
In the present application, the “chain hydrocarbon compound” is a hydrocarbon compound having no cyclic hydrocarbon group. The chain hydrocarbon compound also has a polymerizable group that can form the repeating unit [I] by a polymerization reaction.

  Preferable examples of the chain hydrocarbon compound include a chain conjugated diene compound. Examples of the chain conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and the like. Of these, a chain conjugated diene compound containing no polar group is preferable from the viewpoint of hygroscopicity, and 1,3-butadiene and isoprene are particularly preferable from the viewpoint of industrial availability.

[1.1.1.5. Other vinyl compounds]
Examples of other vinyl compounds include unsaturated imide compounds. These compounds may have a nitrile group, an alkoxycarbonyl group, a hydroxycarbonyl group, or a halogen atom as a substituent.

[1.1.1.6. Block copolymer [C]]
In a preferred example, the number of polymer blocks [A] and polymer blocks [B] contained in one molecule of the block copolymer [C] is usually two polymer blocks [A], and the polymer There is one block [B]. Accordingly, the block copolymer [C] usually has a triblock structure of [A]-[B]-[A]. However, the block copolymer [C] is not limited to one having a triblock structure, and for example, has a pentablock structure of [A]-[B]-[A]-[B]-[A] Also good.

  When the block copolymer [C] has two or more polymer blocks [A], these may be the same as or different from each other. The weight average molecular weights of the two polymer blocks [A] contained in one molecule of the block copolymer [C] may be the same or different. The polymer block [A] has a weight average molecular weight Mw (A) of 3,000 to 90,000, preferably 3,500 to 80,000, more preferably 4,000 to 60,000.

  When the Mw (A) of the polymer block [A] is 3,000 or more, the mechanical strength of the block copolymer hydride [D] can be improved. On the other hand, when the Mw (A) of the polymer block [A] is 90,000 or less, the melt moldability of the block copolymer hydride [D] can be improved.

  In the block copolymer [C], the weight fraction wA of the total polymer block [A] in the block copolymer [C], and the weight of the polymer block [B] in the block copolymer [C]. The fraction wB preferably has a predetermined ratio. That is, the ratio of wA to wB (wA / wB) is preferably 50/50 or higher, more preferably 53/47 or higher, even more preferably 57/43 or higher, while preferably 75/25 or lower, more preferably 70/30 or less, still more preferably 65/35 or less. By setting wA / wB below the upper limit, flexibility can be imparted to the block copolymer hydride [D] and good mechanical strength can be imparted. By setting wA / wB to be equal to or higher than the lower limit, good heat resistance can be imparted.

  The molecular weight of the block copolymer [C] is a polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and preferably 60,000 or more. , More preferably 65,000 or more, even more preferably 70,000 or more, while preferably 150,000 or less, more preferably 130,000 or less, and even more preferably 100,000 or less. Further, the molecular weight distribution (Mw / Mn) of the block copolymer [C] is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less.

  The block copolymer [C] contains a monomer mixture (a) containing a cyclic hydrocarbon group-containing compound as a main component and a chain hydrocarbon compound as a main component, or a cyclic hydrocarbon group-containing compound. And a monomer mixture (b) containing a chain hydrocarbon compound as a main component. For example, a method in which the monomer mixture (a) and the monomer mixture (b) are alternately polymerized by a method such as living anion polymerization; after the monomer mixture (a) and the monomer mixture (b) are sequentially polymerized, the polymer block It can be produced by a method of coupling the ends of [B] with a coupling agent.

  When the monomer mixture (b) contains a cyclic hydrocarbon group-containing compound and a chain hydrocarbon compound as main components, in the step of polymerizing the monomer mixture (b) to form a copolymer block [B], It is preferable to continuously supply the monomer mixture (b) to the polymerization reaction system little by little. Thereby, even when the polymerization rates of the cyclic hydrocarbon group-containing compound and the chain hydrocarbon compound are greatly different, a copolymer block [B] having a homogeneous monomer composition can be formed. Thereby, the heat resistance of block copolymer hydride [D] can be improved.

[1.1.1.7. Block copolymer hydride [D]]
The block copolymer hydride [D] is obtained by hydrogenating the carbon-carbon unsaturated bond of the main chain and side chain of the block copolymer [C] and the carbon-carbon unsaturated bond of the aromatic ring. sell.

The hydrogenation rate of the block copolymer hydride [D] (the ratio of the hydrogenation in the block copolymer hydride [D] out of the total unsaturated bonds of the block copolymer [C]) is preferably It is 90% or more, preferably 95% or more, more preferably 99% or more. The higher the hydrogenation rate, the better the weather resistance, heat resistance and transparency of the molded body. The hydrogenation rate of the block copolymer hydride [D] can be determined by ¹ H-NMR, or comparison of peak areas by GPC UV detector and RI detector.

  There are no particular restrictions on the hydrogenation method or reaction mode of the unsaturated bond, and it can be carried out according to known methods. A hydrogenation method that can increase the hydrogenation rate and has less polymer chain scission reaction is preferred. As an example of such a hydrogenation method, the method described in the international publication 2011/096389 and the method described in the international publication 2012/043708 are mentioned, for example.

  After completion of the hydrogenation reaction, after removing the hydrogenation catalyst and / or the polymerization catalyst from the reaction solution, the block copolymer hydride [D] can be recovered from the resulting solution. The block copolymer hydride [D] is usually in the form of a pellet and can be subjected to subsequent operations.

  The molecular weight of the block copolymer hydride [D] is a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC using THF as a solvent, preferably 50,000 or more, more preferably 55,000 or more, and further More preferably, it is 60,000 or more, while preferably 150,000 or less, more preferably 130,000 or less, and even more preferably 100,000 or less. The molecular weight distribution (Mw / Mn) of the block copolymer hydride [D] is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less. When Mw and Mw / Mn are within the above ranges, heat resistance and mechanical strength against changes in retardation of the molded optical film are good.

[1.1.2. Block copolymer hydride [D] ratio]
When the optical film of the present invention comprises a resin containing a block copolymer hydride [D], the proportion of the block copolymer hydride [D] in the resin is preferably 50% by weight or more, more preferably 70%. % By weight or more, particularly preferably 90% by weight or more. By setting the ratio of the block copolymer hydride [D] within the range, the advantages of the block copolymer hydride [D] such as high mechanical strength and good optical properties can be obtained. In particular, since the optical film of the present invention is a film containing a block copolymer hydride [D], a film having a small front phase difference Re can be easily obtained, and used as a polarizer protective film in a display device. If present, the function as a protective film can be exhibited without impairing the display quality.

[1.1.3. (Optional ingredients)
The resin constituting the pre-treatment film may contain any component other than the block copolymer hydride [D].
Examples of optional components include crosslinking aids. By containing a crosslinking aid, a high degree of crosslinking can be achieved with a small dose of radiation.
Examples of crosslinking aids include oximes such as p-quinone dioxime and p, p′-dibenzoylquinone dioxime; ethylene dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, cyclohexyl methacrylate, acrylic acid / Zinc oxide mixture, acrylates or methacrylates such as allyl methacrylate; vinyl monomers such as divinylbenzene, vinyltoluene, vinylpyridine; hexamethylene diallyl nadiimide, diallyl itaconate, diallyl phthalate, diallyl isophthalate, triallyl cyanurate, tri Allyl compounds such as allyl isocyanurate; males such as N, N′-m-phenylenebismaleimide and N, N ′-(4,4′-methylenediphenylene) dimaleimide And amide compounds. As a crosslinking assistant, one type may be used alone, or two or more types may be used in combination at any ratio. Allyl compounds are preferable from the viewpoint of improving characteristics such as electrical properties, heat resistance, and solvent resistance of the obtained optical film, and triallyl isocyanurate (TAIC) is most preferable from the viewpoint of thermal stability.

  Examples of other optional components include stabilizers such as antioxidants, UV absorbers and light stabilizers; resin modifiers such as lubricants and plasticizers; colorants such as dyes and pigments; antistatic agents and the like A compounding agent is mentioned. These compounding agents can be used individually by 1 type or in combination of 2 or more types, The compounding quantity is suitably selected in the range which does not impair the objective of this invention.

[1.2. Film before processing)
The pre-treatment film used for the production of the optical film of the present invention can be obtained by molding the block copolymer hydride [D] described above into a film shape.

  The method for forming the film is not particularly limited, and a known method such as melt extrusion can be employed.

  You may use the shape | molded film as a film before a process as it is. Or you may perform arbitrary processes other than line irradiation to the shape | molded film, and may use this as a film before a process. For example, the formed film can be stretched to obtain a stretched film, which can be used as a pre-processed film.

  The mode of stretching when performing the stretching process may be any mode such as uniaxial stretching or biaxial stretching. Moreover, when the film before extending | stretching is a long film, the direction of extending | stretching is a vertical direction (direction parallel to the longitudinal direction of an elongate film), a horizontal direction (the width direction of an elongate film). (Parallel direction) and diagonal direction (direction which is neither vertical nor horizontal).

  The draw ratio is preferably 1.1 times or more, more preferably 1.5 times or more, and preferably 7 times or less, more preferably 6 times or less. The stretching temperature is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, while preferably 200 ° C. or lower, more preferably 180 ° C. or lower.

  By performing such stretching treatment, a large-area film can be easily obtained. In addition, since a film containing a block copolymer hydride [D] is employed as a pre-treatment film, a film having a small retardation can be easily obtained even after a stretching process. When such is required, such a film can be easily obtained.

  The dimension of the film before a process can be suitably set so that what has a desired dimension can be obtained as an optical film which is a product. In view of production efficiency, the pre-treatment film is preferably a long film. The thickness of the pre-treatment film is preferably 5 μm or more, more preferably 10 μm or more, while preferably 50 μm or less, more preferably 40 μm or less.

[1.3. Radiation)
The optical film of the present invention can be obtained by performing a line irradiation step of irradiating an electron beam or γ-ray to the pre-treatment film. By employing an electron beam or γ-ray in the beam irradiation step, the irradiation amount can be easily controlled, and the characteristics of the obtained optical film can be easily adjusted. In particular, by employing an electron beam, the line irradiation process can be performed while reducing the occurrence of undesired yellowing of the film.

  In general, a film containing a block copolymer hydride [D] has good mechanical properties such as high mechanical strength and low retardation, but has low resistance to organic solvents and tends to cause blocking. is there. According to the finding of the present inventor, the film before treatment containing the block copolymer hydride [D] is made into a cross-linked product, whereby the solvent resistance can be improved and the occurrence of blocking can be suppressed. Good optical properties such as high mechanical strength and low retardation are maintained without being damaged, and as a result, an optical film having good properties can be obtained.

  The irradiation with the electron beam can be performed, for example, by irradiating the film before processing with an electron beam from a source such as an electron beam irradiation device. The irradiation dose can be appropriately adjusted so that desired solvent resistance and blocking resistance can be obtained. Specifically, the absorbed dose is preferably 200 kGy or more, more preferably 1200 kGy or less, and preferably 800 kGy or less, more preferably 500 kGy or less. The accelerating voltage when irradiating with an electron beam is preferably 150 kV or higher, while preferably 250 kV or lower.

  Irradiation with γ-rays can be performed, for example, by irradiating the pre-treatment film with γ-rays from a radiation source such as a γ-ray irradiation device. The dose can be the same dose as the electron beam as an absorbed dose.

  The atmosphere at the time of performing the beam irradiation process is not particularly limited, and may be an air atmosphere or an inert gas atmosphere. As the inert gas, a gas such as nitrogen, argon, or helium can be used. In particular, an atmosphere having an oxygen concentration of less than 300 ppm is preferable because crosslinking inhibition by oxygen can be suppressed.

  The temperature at the time of performing the beam irradiation process is not particularly limited, and may be room temperature, for example, a temperature of 10 ° C. or higher and 30 ° C. or lower.

[1.4. Properties of optical film etc.)
The optical film of the present invention has a tensile elongation at break of 100% or more. The tensile elongation at break is preferably 110% or more, more preferably 120% or more. On the other hand, the upper limit of the breaking elongation is not particularly limited, but may be, for example, 200% or less. By having a tensile elongation at break in this range, an optical film excellent in blocking resistance can be obtained. An optical film having such a tensile elongation at break can be easily obtained by appropriately adjusting the dose in the line irradiation step. The tensile elongation at break can be determined by using a test piece type 1B test piece described in JISK7127 at a pulling speed of 20 mm / min.

  The dimension of the optical film of the present invention can be appropriately set so as to have a desired dimension according to the use of the product. Since the optical film of the present invention is excellent in blocking resistance, it is excellent in handleability when storing and transporting an optical film or a polarizing plate provided on the optical film in the form of a film roll. Therefore, the optical film of the present invention is preferably a long film. The thickness of the optical film of the present invention is preferably 5 μm or more, more preferably 10 μm or more, while preferably 50 μm or less, more preferably 40 μm or less.

  The optical film of the present invention has a solvent-insoluble component ratio of 85% or more. The solvent-insoluble component ratio is preferably 86% or more, more preferably 87% or more. Although the upper limit of a solvent insoluble component rate is not specifically limited, For example, it can be 100% or less. By having a solvent insoluble component ratio in this range, it can be usefully used as an optical film having high resistance to organic solvents. An optical film having such a solvent-insoluble component ratio can be easily obtained by appropriately adjusting the dose in the line irradiation step. The solvent insoluble component ratio can be measured by the following method. The optical film is cut into a sample having a size of 40 mm × 40 mm. The sample is immersed in 100 mL of toluene for 30 days, and then filtered through a 500 mesh wire mesh. The residue collected by filtration is put into an oven at 100 ° C. and dried for 10 minutes, and the weight of the dried product is measured. The solvent-insoluble component ratio can be determined from the sample weight and the dried filter cake weight by the formula of solvent-insoluble component ratio (%) = (filter filter weight / sample weight) × 100.

  The optical film of the present invention has a front phase difference Re of preferably 5 nm or less, more preferably 4 nm or less. When the value of the front phase difference Re is such a small value, when used as a polarizer protective film in a display device, the function as a protective film can be exhibited without impairing display quality. In the optical film of the present invention having such a small front phase difference Re, the proportion of the repeating units constituting the block copolymer hydride [D] is appropriately adjusted, and the block copolymer hydride [D] in the film is adjusted. By increasing the ratio, it can be easily obtained.

  In the present application, the front phase difference Re of the film is calculated according to the formula Re = (nx−ny) × d. nx is the refractive index in the slow axis direction in the plane of the measurement target (maximum refractive index in the plane), ny is the refractive index in the direction perpendicular to the slow axis in the plane of the measurement target, and nz Is the refractive index in the thickness direction of the measurement object, and d is the thickness (nm) of the measurement object. The measurement wavelength is 590 nm unless otherwise specified.

[2. Polarizer〕
The optical film of the present invention has good mechanical properties such as high mechanical strength and low retardation due to the inclusion of the block copolymer hydride [D], and also has high solvent resistance and occurrence of blocking. Since it is suppressed, in a display device such as a liquid crystal display device and an organic electroluminescence display device, it can be suitably used as a protective film for protecting other layers. In particular, the optical film of the present invention can function particularly well as a protective film for protecting a polarizer in a polarizing plate.

  The polarizing plate of the present invention includes the optical film of the present invention and a polarizer. In the polarizing plate of the present invention, the optical film can function as a polarizer protective film. The polarizing plate of the present invention may further include an adhesive layer for bonding them between the optical film and the polarizer.

  The polarizer is not particularly limited, and any known one can be used. Examples of the polarizer include those obtained by adsorbing a material such as iodine or a dichroic dye on a polyvinyl alcohol film and then stretching the material. Examples of the adhesive constituting the adhesive layer include those having various polymers as base polymers. Examples of such base polymers include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyethers, and synthetic rubbers. When the adhesive is an ultraviolet curable adhesive, the optical film and the polarizer can be bonded via the adhesive and then irradiated with ultraviolet rays as necessary to cure the adhesive layer. In addition, prior to the bonding of the optical film and the polarizer, surface treatment such as corona treatment can be performed as necessary.

  Although the number of layers of the polarizer and the protective film provided in the polarizing plate of the present invention is arbitrary, the polarizing plate of the present invention is usually a single-layer polarizer and a two-layer protective film provided on both surfaces thereof. Can be provided. Of these two protective films, both may be the optical film of the present invention, and only one of them may be the optical film of the present invention.

  The polarizing plate of the present invention can include an arbitrary layer in addition to the optical film and the polarizer of the present invention. For example, various layers that can be formed by applying a composition containing the material of such a layer and an organic solvent to the surface of the optical film and volatilizing the organic solvent can be provided. Since the optical film of the present invention has high resistance to an organic solvent, such an arbitrary layer can be easily formed without impairing optical performance.

  Examples of the optional layer include a matte layer that improves the slipperiness of the film, a hard coat layer such as an impact-resistant polymethacrylate resin layer, an antireflection layer, and an antifouling layer. In particular, the optical film of the present invention preferably has a hard coat layer. By having a hard coat layer, in the display device, the optical film of the present invention can be suitably used as a protective film that is positioned on the display surface side of the display surface side polarizer and constitutes the display surface outermost layer of the device. .

  In a display device, the pencil hardness of the surface constituting the display surface outermost layer of the device is often required to be 2H or more. In the polarizing plate of the present invention, by further forming a hard coat layer on the optical film, the pencil hardness of the surface can be easily set to a high value of 2H or more.

  Examples of the material constituting the hard coat layer include organic hard coat materials such as organic silicone, melamine, epoxy, acrylic, and urethane acrylate; and inorganic hard coat materials such as silicon dioxide. . Of these, urethane acrylate-based and polyfunctional acrylate-based hard coat materials are preferably used from the viewpoint of good adhesive strength and excellent productivity. The thickness of the hard coat layer is preferably 0.3 μm or more, more preferably 0.8 μm or more, particularly preferably 1.0 μm or more, preferably 20 μm or less, more preferably 10 μm or less, and particularly preferably 3 μm or less. . The hard coat layer can be formed by applying a composition of these materials and an organic solvent to the surface of the optical film and volatilizing the organic solvent. Examples of such organic solvents include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone cyclopentanone and cyclohexanone; esters such as ethyl acetate and butyl acetate; alcohols such as isopropyl alcohol and ethyl alcohol; benzene, toluene, xylene and methoxy. Aromatic hydrocarbons such as benzene and 1,2-dimethoxybenzene; phenols such as phenol and parachlorophenol; halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, and chlorobenzene can give. These solvents can be used alone or in combination of two or more.

[3. Display device)
The display device of the present invention includes the optical film of the present invention. The display device of the present invention can be a liquid crystal display device or an organic electroluminescence display device. In the display device of the present invention, the optical film of the present invention can be provided as a protective film for protecting the polarizer in the polarizing plate.

  Usually, the liquid crystal display device includes a light source, a light source side polarizing plate, a liquid crystal cell, and a viewing side polarizing plate in this order. When the display device of the present invention is a liquid crystal display device, the optical film of the present invention can be used, for example, as either a light source side polarizing plate or a viewing side polarizing plate, or both of both surfaces or a single side protective film. Examples of the driving method of the liquid crystal cell of the liquid crystal display device include an in-plane switching (IPS) mode, a vertical alignment (VA) mode, a multi-domain vertical alignment (MVA) mode, a continuous spin wheel alignment (CPA) mode, and a hybrid alignment. Nematic (HAN) mode, Twisted Nematic (TN) mode, Super Twisted Nematic (STN) mode, Optical Compensated Bend (OCB) mode, and the like can be given.

  In the display device of the present invention, the optical film of the present invention can be provided as a protective film in a polarizing plate used for other purposes. For example, a component for expressing an antireflection function, a so-called sunglasses readable function (a function for reducing a display difference depending on an observation angle when an observer wears polarized sunglasses) The optical film of the present invention can be provided as a protective film for a part of the polarizing plate.

  The display device of the present invention may have an arbitrary layer in combination with the optical film. Examples of such an optional layer include layers such as the hard coat layer described as a constituent element of the polarizing plate. The hard coat layer is located closer to the display surface than the polarizer on the display surface side of the display device, and can be provided as a layer constituting the outermost layer of the display surface of the device.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof.
In the following description, “%” and “part” representing amounts are based on weight unless otherwise specified. In addition, the operations described below were performed under normal temperature and normal pressure conditions unless otherwise specified.

〔Evaluation method〕
[Method for measuring weight average molecular weight and number average molecular weight]
The weight average molecular weight and number average molecular weight of the polymer were measured as polystyrene equivalent values using a gel permeation chromatography (GPC) system (“HLC-8320” manufactured by Tosoh Corporation). In the measurement, an H type column (manufactured by Tosoh Corporation) was used as the column, and tetrahydrofuran was used as the solvent. Moreover, the temperature at the time of measurement was 40 degreeC.

[Method of measuring glass transition temperature Tg]
A sample was press-molded to produce a test piece having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm. Based on the JIS-K7244-4 method, a viscoelasticity measuring device (manufactured by TA Instruments Japan, ARES) was used to measure the viscoelastic spectrum in the range of −100 ° C. to + 150 ° C. at a temperature rising rate of 5 ° C./min. From the peak top temperature on the low temperature side of the loss tangent tan δ, the glass transition temperature Tg1 derived from the soft segment and the glass transition temperature Tg2 derived from the hard segment were determined from the peak top temperature on the high temperature side.

[Method for Measuring Hydrogenation Rate of Block Copolymer Hydride [D]]
The hydrogenation rate of the polymer was measured by ¹ H-NMR measurement at 145 ° C. using orthodichlorobenzene-d ₄ as a solvent.

(Measurement of elongation at break)
The breaking elongation was determined by using a test piece type 1B test piece described in JISK7127 at a pulling speed of 20 mm / min.

[Measurement of retardation]
The front phase difference Re was measured at a measurement wavelength of 590 nm using an automatic birefringence meter (“KOBRA-21ADH” manufactured by Oji Scientific Instruments).

[Measurement method of solvent insoluble component ratio]
The optical film was cut into a sample having a size of 40 mm × 40 mm. In addition, a 500 mesh wire mesh was prepared, and the weight was measured with an electronic balance. The sample was placed on a wire mesh, the total weight of the film and the wire mesh was measured with an electronic balance, and the sample weight was determined. Thereafter, the sample was immersed so that the entire sample was immersed in a glass bottle containing 100 mL of toluene. After standing for 30 days, the contents of the glass bottle were filtered through the above-mentioned wire mesh, and the filtered material was put into an oven at 100 ° C. together with the wire mesh and dried for 10 minutes. Thereafter, the total weight of the wire mesh and the filtered material was measured with an electronic balance to determine the weight of the filtered material. The solvent insoluble component ratio was calculated by the following formula.
Solvent insoluble component ratio (%) = (weight of filtered material / sample weight) × 100

[Example 1]
(1-1. Block copolymer [C])
A stainless steel reactor equipped with a stirrer and thoroughly dried and purged with nitrogen was charged with 256 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene, and 0.65 part of n-dibutyl ether, and stirred at 60 ° C. 1.35 parts of n-butyllithium (15% cyclohexane solution) was added to initiate the polymerization reaction. Furthermore, it was made to react at 60 degreeC for 60 minutes, stirring. The polymerization conversion rate at this point was 99.5% (measured by gas chromatography, the same applies hereinafter). Next, 50.0 parts of dehydrated isoprene was added, and stirring was continued at the same temperature for 30 minutes. At this time, the polymerization conversion rate was 99%. Thereafter, 25.0 parts of dehydrated styrene was further added and stirred at the same temperature for 60 minutes. The polymerization conversion rate at this point was almost 100%. Next, 0.5 part of isopropyl alcohol was added to the reaction solution to stop the reaction, and a polymerization reaction solution containing a block copolymer [C] was obtained. The resulting block copolymer [C] had a weight average molecular weight (Mw) of 44,900 and a molecular weight distribution (Mw / Mn) of 1.03.

(1-2. Block copolymer hydride [D])
The polymerization reaction solution obtained in (1-1) was transferred to a pressure-resistant reactor equipped with a stirrer, and a silica-alumina supported nickel catalyst (E22U, nickel supported amount 60%; manufactured by JGC Chemical Industries, Ltd.) as a hydrogenation catalyst. ) 4.0 parts and 350 parts dehydrated cyclohexane were added and mixed. The inside of the reactor was replaced with hydrogen gas, and hydrogen was supplied while stirring the solution. A hydrogenation reaction was performed at a temperature of 170 ° C. and a pressure of 4.5 MPa for 6 hours.

  After completion of the hydrogenation reaction, the reaction solution was filtered to remove the hydrogenation catalyst. Pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (product of Koyo Chemical Laboratory Co., Ltd., product name “Songnox 1010”, which is a phenolic antioxidant, was added to the filtrate. ) 1.0 part of xylene solution in which 0.1 part was dissolved was added and dissolved. Next, the above solution was subjected to cyclohexane, xylene and other volatilizations from the solution at a temperature of 260 ° C. and a pressure of 0.001 MPa or less using a cylindrical concentrating dryer (product name “Kontoro” manufactured by Hitachi, Ltd.). Ingredients were removed. The molten polymer is continuously filtered at a temperature of 260 ° C. with a polymer filter (manufactured by Fuji Filter Co., Ltd.) equipped with a stainless sintered filter having a pore diameter of 20 μm connected to a concentrating dryer, and then the molten polymer is stranded from the die. After extrusion and cooling, a block copolymer hydride [D] was obtained by a pelletizer.

  The obtained block copolymer hydride [D] includes a block containing repeating units derived from styrene (hereinafter referred to as “St” as appropriate) and a block containing repeating units derived from isoprene (hereinafter referred to as “Ip” as appropriate). The weight ratio of each block was St: Ip: St = 25: 50: 25. The block copolymer hydride [D] has an Mw of 45,100, an Mw / Mn of 1.04, a hydrogenation rate of the main chain and the aromatic ring of almost 100%, a glass transition temperature Tg1 of −50 ° C., and a Tg2 of 140 ° C.

(1-3. Preparation of resin)
A film obtained by mixing 100 parts of the block copolymer hydride [D] obtained in (1-2) with 5 parts of a crosslinking aid (triallyl isocyanurate, product name Thaik, manufactured by Nippon Kasei Co., Ltd.) As a result, a resin was obtained.

(1-4. Production of film before treatment)
The resin obtained in (1-3) was charged into a twin screw extruder having four die holes with an inner diameter of 3 mm. The resin was molded into a strand-shaped molded body by hot melt extrusion molding using the above-described twin-screw extruder. The molded body was chopped with a strand cutter to obtain resin pellets. The operating conditions of the above twin screw extruder are shown below.
-Barrel set temperature: 270 ° C to 280 ° C
・ Die setting temperature: 250 ℃
・ Screw speed: 145rpm
・ Feeder rotation speed: 50 rpm

Subsequently, the obtained pellets were supplied to a hot melt extrusion film forming machine equipped with a T die. Resin was extruded from a T-die and wound on a roll at a speed of 1 m / min to produce a long pre-treatment film (thickness 100 μm) made of the resin. The operating conditions of the film forming machine are shown below.
・ Barrel temperature setting: 280 ℃ ～ 290 ℃
-Die temperature: 270 ° C
-Screw rotation speed: 60rpm

(1-5. Production and evaluation of optical film)
Using an electron beam irradiation apparatus (manufactured by I. Electron Beam Co., Ltd.) so that the pre-treatment film obtained in (1-4) has an absorbed dose of 800 kGy under conditions of electron beam irradiation atmosphere oxygen concentration of 300 ppm or less and acceleration voltage of 200 kV An optical film was obtained by irradiation with an electron beam. About the obtained optical film, front phase difference Re, tensile elongation at break, and solvent insoluble component ratio were measured.

[Example 2]
(2-1. Block copolymer [C])
A stainless steel reactor equipped with a stirrer that was thoroughly dried and purged with nitrogen was charged with 256 parts of dehydrated cyclohexane, 20.0 parts of dehydrated styrene, and 0.65 part of n-dibutyl ether and stirred at 60 ° C. 1.35 parts of n-butyllithium (15% cyclohexane solution) was added to initiate the polymerization reaction. Furthermore, it was made to react at 60 degreeC for 60 minutes, stirring. Next, 20.0 parts of dehydrated isoprene was added and stirring was continued for 30 minutes at the same temperature. Thereafter, 20.0 parts of dehydrated styrene was further added and stirred at the same temperature for 60 minutes. Furthermore, 20.0 parts of dehydrated isoprene was added and stirring was continued for 30 minutes at the same temperature. Thereafter, 20.0 parts of dehydrated styrene was further added and stirred at the same temperature for 60 minutes. The polymerization conversion rate at this point was almost 100%. Next, 0.5 part of isopropyl alcohol was added to the reaction solution to stop the reaction, and a polymerization reaction solution containing a block copolymer [C] was obtained.
When the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the obtained block copolymer [C] were measured, they were Mw = 91,000 and Mw / Mn = 1.03.

(2-2. Block copolymer hydride [D])
(1-2) of Example 1 except that the polymerization reaction solution containing the block copolymer [C] was replaced by the polymerization reaction solution obtained in (2-1) instead of the one obtained in (1-1). In the same manner as above, a block copolymer hydride [D] was obtained.

  The obtained block copolymer hydride [D] is a ternary block copolymer composed of St and Ip, and the weight ratio of each block is St: Ip: St: Ip: St = 20: 20. : 20: 20: 20. The block copolymer hydride [D] had an Mw of 92,000, an Mw / Mn of 1.05, a hydrogenation rate of almost 100%, a glass transition temperature Tg1 of -45 °, and a Tg2 of 137 ° C.

(2-3. Production of optical film)
(1-4) to (1-5) in Example 1 except that instead of the resin obtained in (1-3), the block copolymer hydride [D] obtained in (2-2) was used. The optical film was produced and evaluated in the same manner as in (1).

Example 3
(3-1. Block copolymer [C])
A stainless steel reactor equipped with a stirrer and thoroughly dried and purged with nitrogen was charged with 256 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene, and 0.65 part of n-dibutyl ether, and stirred at 60 ° C. The polymerization reaction was initiated by adding 0.82 parts of n-butyllithium (15% cyclohexane solution). Furthermore, it was made to react at 60 degreeC for 60 minutes, stirring. The polymerization conversion rate at this time was 99.5%.
Next, 50 parts of a mixed monomer composed of 25 parts of styrene monomer and 25 parts of isoprene monomer was continuously added to the reaction solution over 150 minutes, and stirring was continued for 20 minutes after completion of the addition. The polymerization conversion rate at this time was 99.5%. Thereafter, 25.0 parts of dehydrated styrene was further added and stirred at the same temperature for 60 minutes. The polymerization conversion rate at this point was almost 100%. Next, 0.5 part of isopropyl alcohol was added to the reaction solution to stop the reaction, and a polymerization reaction solution containing a block copolymer [C] was obtained. The obtained block copolymer [C] had a weight average molecular weight (Mw) of 58,000 and a molecular weight distribution (Mw / Mn) of 1.03.

(3-2. Block copolymer hydride [D])
(1-2) of Example 1 except that the polymerization reaction solution containing the block copolymer [C] was replaced by the one obtained in (3-1) instead of the one obtained in (1-1). In the same manner as above, a block copolymer hydride [D] was obtained.

  The obtained block copolymer is a ternary block copolymer comprising St, a block in which a repeating unit derived from styrene and a repeating unit derived from isoprene coexist (hereinafter referred to as “St / Ip” as appropriate) and Ip. It was a polymer, and the weight ratio of each block was St: St / Ip: St = 25: 25/25: 25. The block copolymer had Mw of 59,000, Mw / Mn of 1.05, a hydrogenation rate of almost 100%, a glass transition temperature Tg1 of 15 ° C., and Tg2 of 129 ° C.

(3-3. Production of optical film)
An optical film was produced and evaluated in the same manner as (1-4) to (1-5) in Example 1 except for the following items.
-It replaced with resin obtained by (1-3), and used the block copolymer hydride [D] obtained by (3-2).
In (1-5), the acceleration voltage was changed to 250 kV and the dose was changed to 400 kGy.

[Comparative Example 1]
An optical film was produced and evaluated in the same manner as in Example 2 except that the electron beam irradiation was not performed.

[Comparative Example 2]
An optical film was produced and evaluated in the same manner as in Example 1 except that γ-ray irradiation was performed instead of electron beam irradiation, the irradiation dose was 100 kGy, and irradiation was performed in the atmosphere.

[Comparative Example 3]
In (1-5), an optical film was produced and evaluated in the same manner as in Example 3 except that the acceleration voltage was changed to 250 kV and the dose was changed to 1200 kGy.

[Comparative Example 4]
(C4-1. First-stage polymerization reaction: extension of block A1)
A stainless steel reactor equipped with a stirrer and thoroughly dried and purged with nitrogen was charged with 320 parts of dehydrated cyclohexane, 55 parts of styrene, and 0.38 part of dibutyl ether, and stirred at 60 ° C. to obtain an n-butyllithium solution. (A 15 wt% hexane solution) 0.56 part was added to initiate the polymerization reaction, and the first stage polymerization reaction was performed. At 1 hour after the start of the reaction, the polymerization conversion was 99.5%.

(C4-2. Second stage reaction: extension of block B)
To the reaction mixture obtained in (C4-1), 40 parts of a mixed monomer composed of 20 parts of styrene and 20 parts of isoprene was added, and then the second stage polymerization reaction was started. At 1 hour after the start of the second stage polymerization reaction, the polymerization conversion was 99.5%.

(C4-3. Third stage reaction: extension of block A2)
5 parts of styrene was added to the reaction mixture obtained in (C4-2), and then the third stage polymerization reaction was started. As a result of sampling and analyzing a sample from the reaction mixture at 1 hour after the start of the third stage polymerization reaction, the polymerization conversion was almost 100%. Immediately thereafter, 0.2 part of isopropyl alcohol was added to the reaction mixture to stop the reaction. This obtained the mixture containing the block copolymer [C] which has a triblock molecular structure of A1-B-A2.

In (C4-1) and (C4-2), since the polymerization reaction was sufficiently advanced, the polymerization conversion rate was about 100%. Therefore, the weight ratio of St / Ip in block B was 20/20. Conceivable.
From these values, the obtained block copolymer [C] was found to be a polymer having a triblock molecular structure of St- (St / Ip) -St = 55- (20/20) -5. It was.

(C4-4. Block copolymer hydride [D])
Next, the mixture containing the block copolymer [C] is transferred to a pressure-resistant reactor equipped with a stirrer, and a diatomaceous earth-supported nickel catalyst (product name “E22U”, nickel-supported amount 60%, (JGC Catalysts & Chemicals Co., Ltd.) 8.0 parts and dehydrated cyclohexane 100 parts were added and mixed. The inside of the reactor was replaced with hydrogen gas, and hydrogen was supplied while stirring the solution. A hydrogenation reaction was performed at a temperature of 190 ° C. and a pressure of 4.5 MPa for 6 hours. The weight average molecular weight (Mw) of the block copolymer hydride contained in the reaction solution obtained by the hydrogenation reaction was 76,000, and the molecular weight distribution (Mw / Mn) was 1.05.

After completion of the hydrogenation reaction, the reaction solution was filtered to remove the hydrogenation catalyst, and then the phenol-based antioxidant pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl). ) Propionate] (product name “Songnox 1010”, manufactured by Matsubara Sangyo Co., Ltd.) 2.0 parts of xylene solution in which 0.1 part was dissolved was added and dissolved.
Next, the above solution is mixed with a solvent such as cyclohexane, xylene and other solvents at a temperature of 260 ° C. and a pressure of 0.001 MPa or less using a cylindrical concentrating dryer (product name “Contro”, manufactured by Hitachi, Ltd.). Volatile components were removed. The molten polymer was extruded into a strand form from a die, and after cooling, 95 parts of pellets of the block copolymer hydride [D] were produced by a pelletizer.
The pelletized block copolymer hydride [D] had a weight average molecular weight (Mw) of 77,000, a molecular weight distribution (Mw / Mn) of 1.06, and a hydrogenation rate of almost 100%.

(C4-5. Production of optical film)
An optical film was produced and evaluated in the same manner as (1-4) to (1-5) in Example 1 except for the following items.
-Instead of the resin obtained in (1-3), the block copolymer hydride [D] obtained in (C4-4) was used.
In (1-5), the acceleration voltage was changed to 250 kV and the dose was changed to 400 kGy.

  The results of Examples and Comparative Examples are summarized in Table 1.

  From the results of Table 1, in the present application example, the film has a low front phase difference Re, a high tensile elongation at break, and a high solvent-insoluble component ratio by irradiation of the pre-treatment film. It turns out that the optical film which can be used usefully was obtained.

Claims (9)

An optical film comprising a cross-linked product of a pre-treatment film containing a block copolymer hydride [D],
The block copolymer hydride [D] is:
Two or more polymer blocks [A] based on a repeating unit [I] derived from a cyclic hydrocarbon group-containing compound;
A block copolymer consisting of a repeating unit [II] derived from a chain hydrocarbon compound, or one or more polymer blocks [B] having as a main component a combination of the repeating unit [I] and the repeating unit [II] Hydrogenate the union [C]:
(I) The ratio of wA to wB (wA / wB) is 50/50 to 75/25, where wA is the weight fraction of the polymer block [A] in the block copolymer [C]. WB is a weight fraction of the polymer block [B] in the block copolymer [C],
(Ii) The ratio of w [IB] to w [IIB] (w [IB] / w [IIB]) is 50/50 to 0/100, where w [IB] is the polymer block [B ] And the weight fraction of the repeating unit [I] in the polymer block [B], and w [IIB] is the weight fraction of the repeating unit [II] in the polymer block [B].
(Iii) The block copolymer hydride [D] is obtained by hydrogenating 90% or more of the total unsaturated bonds of the block copolymer [C],
The optical film is:
(Iv) The tensile elongation at break is 100% or more,
(V) An optical film having a solvent-insoluble component ratio of 85% or more.   The optical film according to claim 1, wherein the cyclic hydrocarbon group-containing compound is an aromatic vinyl compound, and the chain hydrocarbon compound is a chain conjugated diene compound.   The optical film according to claim 1 or 2, wherein the front phase difference Re is 5 nm or less.   The optical film of any one of Claims 1-3 formed by irradiating an electron beam or a gamma ray to the film before a process containing the said block copolymer hydride [D]. It is a manufacturing method of the optical film given in any 1 paragraph of Claims 1-4,
The manufacturing method including the line irradiation process of irradiating an electron beam or a gamma ray to the film before a process containing block copolymer hydride [D].   The manufacturing method according to claim 5, wherein an oxygen concentration in an atmosphere in which the line irradiation step is performed is smaller than 300 ppm.   The manufacturing method according to claim 5 or 6, wherein a dose in the line irradiation step is 200 kGy or more and 800 kGy or less.   A polarizing plate provided with the optical film of any one of Claims 1-4, and a polarizer.   A display apparatus provided with the optical film of any one of Claims 1-4.