JP2017134305A - Stretched film, production method, polarizing plate and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film and a production method of the film having high mechanical strength, good optical characteristics as well as high peeling strength, and advantageously usable as a protective film of a polarizing plate, a polarizing plate having high mechanical strength and good optical characteristics as well as high peeling strength, and a display device having high mechanical strength and good optical performance.SOLUTION: A stretched film is obtained by irradiating an untreated stretched film comprising an alicyclic structure-containing polymer with an electron beam or γ rays. A peeling strength Fa of the untreated stretched film when a surface of the untreated stretched film is bonded to a surface of an adherend, and a peeling strength Fb of the stretched film when a surface of the stretched film is bonded to the surface of the adherend satisfy a relationship of Fb≥1.2Fa. A production method of the stretched film, and a polarizing plate and a display device including the stretched film are also disclosed.SELECTED DRAWING: None

Description

  The present invention relates to a stretched film, a method for producing the stretched film, and uses thereof, and particularly relates to a stretched 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 (see Patent Documents 1 and 2). 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.

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, when the work is reworked during manufacture of the display device and when the polarizer contracts during use of the display device, the peel strength of the protective film on the polarizing plate may be required to be high.

  However, conventionally, when a resin film containing an alicyclic structure-containing polymer is used as a protective film, the peel strength may be insufficient. In particular, when the protective film is a stretched film manufactured through a stretching process, the peeling strength is caused by cohesive failure in the vicinity of the surface layer caused by orientation of the polymer molecules and a decrease in entanglement between the molecules. A shortage can occur.

  Accordingly, an object of the present invention is to provide a film that can be used effectively as a protective film in a polarizing plate in addition to having high mechanical strength and good optical properties, and having high peel strength, a method for producing the same, and mechanical strength. Another object of the present invention is to provide a polarizing plate having high peel strength, in addition to high optical properties and good optical characteristics, and a display device having high mechanical strength and good optical performance.

As a result of studying to solve the above-mentioned problems and achieving the object, the present inventors have stretched a resin film containing an alicyclic structure-containing polymer, and further applied a specific treatment to the above-mentioned problems. The inventors have found that this can be solved, and completed the present invention.
That is, according to the present invention, the following [1] to [9] are provided.

[1] A stretched film formed by irradiating a stretched film containing an alicyclic structure-containing polymer with an electron beam or γ rays,
The peel strength Fa when the surface of the stretched film before treatment and the surface of the adherend are bonded, and the peel strength Fb when the surface of the stretched film and the surface of the adherend are bonded, A stretched film that satisfies the relationship of Fb ≧ 1.2 Fa.
[2] The stretched film according to [1], wherein the alicyclic structure-containing polymer is crystalline and has a crystallinity of 1% or more.
[3] The stretched film according to [1], wherein the alicyclic structure-containing polymer is amorphous.
[4] The alicyclic structure-containing polymer is:
Two or more polymer blocks [A] per molecule mainly composed of a repeating unit [I] derived from an aromatic vinyl compound;
It is composed of a repeating unit [II] derived from a chain conjugated diene compound, or one or more polymer blocks [B] per molecule mainly composed of a combination of the repeating unit [I] and the repeating unit [II]. A block copolymer hydride [D] obtained by hydrogenating a block copolymer [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 stretched film according to [1].
[5] A method for producing a stretched film according to any one of [1] to [4],
The manufacturing method including the line | wire irradiation process of irradiating an electron beam or a gamma ray to the stretched film before a process containing an alicyclic structure containing polymer.
[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 500 kGy or more and 1500 kGy or less.
[8] A polarizing plate comprising the stretched film according to any one of [1] to [4] and a polarizer.
[9] A display device comprising the stretched film according to any one of [1] to [4].

  The stretched film of the present invention has high mechanical strength and good optical properties, and also has high peel strength, and can be usefully used as a protective film in a polarizing plate. According to the method for producing a stretched film of the present invention, such a stretched film of the present invention can be easily produced. The polarizing plate of the present invention can have high peel strength in addition to high mechanical strength and good optical properties. 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. Stretched film and manufacturing method thereof: overview]
The stretched film of the present invention is formed by irradiating a specific pre-treated stretched film with an electron beam or γ-ray. In the description of the present application, the stretched film of the present invention may be particularly referred to as a “line irradiation stretched film” for the sake of clear distinction from general stretched films. In addition, among the irradiated film, the film irradiated with an electron beam and the film irradiated with γ-ray may be referred to as “electron beam irradiated stretched film” and “γ-ray irradiated stretched film”, respectively.

[1.1. Material of stretched film before treatment]
The pre-treated stretched film contains an alicyclic structure-containing polymer. The stretched film before treatment can be usually made of a resin containing an alicyclic structure-containing polymer. Examples of the alicyclic structure-containing polymer include a crystalline alicyclic structure-containing polymer, a non-crystalline alicyclic structure-containing polymer, and a specific block copolymer hydride [D]. Examples thereof include cyclic structure-containing polymers.

[1.1.1. (Crystalline alicyclic structure-containing polymer)
The polymer having crystallinity refers to a polymer having a melting point [that is, the melting point can be observed with a differential scanning calorimeter (DSC)].

  The alicyclic structure-containing polymer refers to a polymer having an alicyclic structure in the molecule, which can be obtained by a polymerization reaction using a cyclic olefin as a monomer, or a hydrogenated product thereof. Since the alicyclic structure-containing polymer having crystallinity is excellent in heat resistance and low hygroscopicity, a film suitable for optical use can be realized. Moreover, an alicyclic structure containing polymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Examples of the alicyclic structure possessed by the alicyclic structure-containing polymer include a cycloalkane structure and a cycloalkene structure. Among these, a cycloalkane structure is preferable because a film excellent in characteristics such as thermal stability is 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. is there. When the number of carbon atoms contained in one alicyclic structure is within the above range, mechanical strength, heat resistance, and moldability are highly balanced.

In the alicyclic structure-containing polymer, 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 proportion of structural units having an alicyclic structure in the alicyclic structure-containing polymer as described above.
In the alicyclic structure-containing polymer, the remainder other than the structural unit having an alicyclic structure is not particularly limited and may be appropriately selected according to the purpose of use.

Examples of the alicyclic structure-containing polymer include the following polymer (α) to polymer (δ). Among these, the polymer (β) is preferable as the crystalline alicyclic structure-containing polymer because a film excellent in heat resistance can be easily obtained.
Polymer (α): A ring-opening polymer of a cyclic olefin monomer having crystallinity.
Polymer (β): A hydrogenated product of polymer (α) having crystallinity.
Polymer (γ): An addition polymer of a cyclic olefin monomer having crystallinity.
Polymer (δ): A hydrogenated product of polymer (γ) having crystallinity.

  Specifically, as the alicyclic structure-containing polymer, a ring-opening polymer of dicyclopentadiene having crystallinity, and a hydrogenated product of a ring-opening polymer of dicyclopentadiene and crystallizing. More preferred is a hydrogenated product of a ring-opening polymer of dicyclopentadiene, and particularly preferred is a crystalline product having crystallinity. Here, the ring-opening polymer of dicyclopentadiene means that the proportion of structural units derived from dicyclopentadiene relative 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 a polymer of 100% by weight.

Hereinafter, the manufacturing method of a polymer ((alpha)) and a polymer ((beta)) is demonstrated.
The cyclic olefin monomer that can be used for the production of the polymer (α) and the polymer (β) is a compound having a ring structure formed of carbon atoms and having a carbon-carbon double bond in the ring. . Examples of the cyclic olefin monomer include norbornene monomers. Moreover, when a polymer ((alpha)) is a copolymer, you may use a monocyclic olefin as a cyclic olefin monomer.

The norbornene monomer is a monomer containing a norbornene ring. Examples of the norbornene-based monomer include bicyclo [2.2.1] hept-2-ene (common name: norbornene), 5-ethylidene-bicyclo [2.2.1] hept-2-ene (common name). : Ethylidene norbornene) and derivatives thereof (for example, those having a substituent in the ring); tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene (conventional Name: dicyclopentadiene) and derivatives thereof; 7,8-benzotricyclo [4.3.0.1 ^2,5 ] dec-3-ene (common name: methanotetrahydrofluorene) : 1,4-methano-1,4,4a, 9a-tetrahydrofluorene) and derivatives thereof, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene (common name: tetracyclododecene), 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene and its derivatives, and the like;

  Examples of the substituent in the monomer include an alkyl group such as a methyl group and an ethyl group; an alkenyl group such as a vinyl group; an alkylidene group such as propan-2-ylidene; an aryl group such as a phenyl group; a hydroxy group; An acid anhydride group; a carboxyl group; an alkoxycarbonyl group such as a methoxycarbonyl group; and the like. Moreover, the said substituent may have 1 type independently and may have 2 or more types by arbitrary ratios.

  Examples of the monocyclic olefin include cyclic monoolefins such as cyclobutene, cyclopentene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, cyclooctene; cyclohexadiene, methylcyclohexadiene, cyclooctadiene, methylcyclooctadiene, phenylcyclohexane Cyclic diolefins such as octadiene; and the like.

  A cyclic olefin monomer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. When two or more cyclic olefin monomers are used, the polymer (α) may be a block copolymer or a random copolymer.

  The cyclic olefin monomer may have a stereoisomer of an endo isomer and an exo isomer. As the cyclic olefin monomer, either an endo isomer or an exo isomer may be used. Moreover, only one isomer among the endo isomer and the exo isomer may be used alone, or an isomer mixture containing the endo isomer and the exo isomer in an arbitrary ratio may be used. Especially, since the crystallinity of an alicyclic structure containing polymer increases and it becomes easy to obtain the film which is excellent with heat resistance, it is preferable to make the ratio of one stereoisomer high. For example, the ratio of endo-form or exo-form is preferably 80% or more, more preferably 90% or more, and still more preferably 95% or more. Moreover, since synthesis | combination is easy, it is preferable that the ratio of an end body is high.

  The polymer (α) and the polymer (β) can generally have high crystallinity by increasing the degree of syndiotactic stereoregularity (racemo dyad ratio). From the viewpoint of increasing the degree of stereoregularity of the polymer (α) and the polymer (β), the ratio of the racemo dyad to the structural units of the polymer (α) and the polymer (β) is preferably 51%. Above, more preferably 60% or more, particularly preferably 70% or more.

The ratio of racemo dyad can be measured by ¹³ C-NMR spectral analysis. Specifically, it can be measured by the following method.
A polymer sample is subjected to ¹³ C-NMR measurement using ortho-dichlorobenzene-d ⁴ as a solvent at 200 ° C. by applying an inverse-gate decoupling method. From the result of ¹³ C-NMR measurement, a signal of 43.35 ppm derived from meso dyad and a signal of 43.43 ppm derived from racemo dyad were obtained with a peak of 127.5 ppm of orthodichlorobenzene-d ⁴ as a reference shift. Based on the intensity ratio, the ratio of the racemo dyad in the polymer sample can be determined.

  A ring-opening polymerization catalyst is usually used for the synthesis of the polymer (α). A ring-opening polymerization catalyst may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. As the ring-opening polymerization catalyst for synthesizing such a polymer (α), those capable of ring-opening polymerization of a cyclic olefin monomer to produce a ring-opening polymer having syndiotactic stereoregularity are preferable. Preferred examples of the ring-opening polymerization catalyst include those containing a metal compound represented by the following formula (A).

M (NR ¹ ) X _4-a (OR ² ) _a · L _b (A)
(In Formula (A),
M represents a metal atom selected from the group consisting of Group 6 transition metal atoms in the periodic table,
R ¹ is a phenyl group optionally having a substituent at at least ^one of the 3-position, 4-position and 5-position, or —CH ₂ R ³ (R ³ has a hydrogen atom or a substituent. And a group selected from the group consisting of an optionally substituted alkyl group and an optionally substituted aryl group).
R ² represents a group selected from the group consisting of an alkyl group which may have a substituent and an aryl group which may have a substituent;
X represents a group selected from the group consisting of a halogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, and an alkylsilyl group;
L represents an electron-donating neutral ligand;
a represents a number of 0 or 1,
b shows the integer of 0-2. )

  In the formula (A), M represents a metal atom selected from the group consisting of Group 6 transition metal atoms in the periodic table. As M, chromium, molybdenum and tungsten are preferable, molybdenum and tungsten are more preferable, and tungsten is particularly preferable.

In the formula (A), R ¹ represents a phenyl group which may have a substituent at at least one of the 3-position, 4-position and 5-position, or a group represented by —CH ₂ R ^3. .
The number of carbon atoms of the phenyl group which may have a substituent at at least ^one of the 3-position, 4-position and 5-position of R ¹ is preferably 6-20, more preferably 6-15. Examples of the substituent include alkyl groups such as methyl group and ethyl group; halogen atoms such as fluorine atom, chlorine atom and bromine atom; alkoxy groups such as methoxy group, ethoxy group and isopropoxy group; It is done. These substituents may have one type independently, and may have two or more types in arbitrary ratios. Furthermore, in R ¹ , substituents present in at least two positions of the 3-position, 4-position and 5-position may be bonded to each other to form a ring structure.

  Examples of the phenyl group optionally having a substituent at the 3-position, 4-position and 5-position include an unsubstituted phenyl group; a 4-methylphenyl group, a 4-chlorophenyl group, and 3-methoxyphenyl. Groups, monosubstituted phenyl groups such as 4-cyclohexylphenyl group, 4-methoxyphenyl group; 3,5-dimethylphenyl group, 3,5-dichlorophenyl group, 3,4-dimethylphenyl group, 3,5-dimethoxyphenyl group Disubstituted phenyl group such as 3,4,5-trimethylphenyl group, trisubstituted phenyl group such as 3,4,5-trichlorophenyl group; 2-naphthyl group, 3-methyl-2-naphthyl group, 4-methyl 2-naphthyl group optionally having a substituent such as a 2-naphthyl group;

In the group represented by —CH ₂ R ³ in R ¹ , R ³ includes a hydrogen atom, an alkyl group which may have a substituent, and an aryl group which may have a substituent. Indicates a group selected from the group.
The number of carbon atoms of the alkyl group which may have a substituent of R ³ is preferably 1-20, more preferably 1-10. This alkyl group may be linear or branched. Furthermore, examples of the substituent include a phenyl group which may have a substituent such as a phenyl group or a 4-methylphenyl group; an alkoxyl group such as a methoxy group or an ethoxy group; These substituents may be used alone or in combination of two or more at any ratio.
Examples of the alkyl group which may have a substituent for R ³ include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, neopentyl group, benzyl Group, neophyll group and the like.

The number of carbon atoms of the aryl group which may have a substituent of R ³ is preferably 6 to 20, and more preferably 6 to 15. Furthermore, examples of the substituent include alkyl groups such as methyl group and ethyl group; halogen atoms such as fluorine atom, chlorine atom and bromine atom; alkoxy groups such as methoxy group, ethoxy group and isopropoxy group; It is done. These substituents may be used alone or in combination of two or more at any ratio.
Examples of the aryl group of R ³ which may have a substituent include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 4-methylphenyl group, and a 2,6-dimethylphenyl group. .

Among these, the group represented by R ³ is preferably an alkyl group having 1 to 20 carbon atoms.

In the formula (A), R ² represents a group selected from the group consisting of an alkyl group which may have a substituent and an aryl group which may have a substituent. As the alkyl group which may have a substituent of R ² and the aryl group which may have a substituent, an alkyl group which may have a substituent of R ³ , respectively, And what was selected from the range shown as the aryl group which may have a substituent can be used arbitrarily.

In the formula (A), X represents a group selected from the group consisting of a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, and an alkylsilyl group. Show.
Examples of the halogen atom for X include a chlorine atom, a bromine atom, and an iodine atom.
As the alkyl group which may have a substituent of X and the aryl group which may have a substituent, an alkyl group which may have a substituent of R ³ , and , Those selected from the ranges indicated as the aryl group which may have a substituent may be arbitrarily used.
Examples of the alkylsilyl group of X include a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, and the like.
When the metal compound represented by the formula (A) has two or more Xs in one molecule, these Xs may be the same or different from each other. Further, two or more Xs may be bonded to each other to form a ring structure.

In the formula (A), L represents an electron-donating neutral ligand.
Examples of the electron donating neutral ligand of L include an electron donating compound containing an atom of Group 14 or Group 15 of the Periodic Table. Specific examples thereof include phosphines such as trimethylphosphine, triisopropylphosphine, tricyclohexylphosphine, and triphenylphosphine; ethers such as diethyl ether, dibutyl ether, 1,2-dimethoxyethane, and tetrahydrofuran; trimethylamine, triethylamine, pyridine, Amines such as lutidine; and the like. Among these, ethers are preferable. Moreover, when the metal compound shown by Formula (A) has two or more L in 1 molecule, those L may mutually be the same and may differ.

As the metal compound represented by the formula (A), a tungsten compound having a phenylimide group is preferable. That is, in the formula (A), a compound in which M is a tungsten atom and R ¹ is a phenyl group is preferable. Furthermore, among them, a tetrachlorotungsten phenylimide (tetrahydrofuran) complex is more preferable.

  The method for producing the metal compound represented by the formula (A) is not particularly limited. For example, as described in JP-A-5-345817, an oxyhalide of a Group 6 transition metal; phenyl optionally having a substituent at at least one of the 3-position, 4-position and 5-position By mixing an isocyanate or monosubstituted methyl isocyanate; an electron-donating neutral ligand (L); and optionally alcohols, metal alkoxides and metal aryloxides; ) Can be produced.

  In the said manufacturing method, the metal compound shown by Formula (A) is normally obtained in the state contained in the reaction liquid. After the production of the metal compound, the reaction solution may be used as it is as a catalyst solution for the ring-opening polymerization reaction. Moreover, after isolating and refine | purifying a metal compound from a reaction liquid by refinement | purification processes, such as crystallization, you may use the obtained metal compound for ring-opening polymerization reaction.

  As the ring-opening polymerization catalyst, the metal compound represented by the formula (A) may be used alone, or the metal compound represented by the formula (A) may be used in combination with other components. For example, the polymerization activity can be improved by using a combination of a metal compound represented by the formula (A) and an organometallic reducing agent.

  Examples of the organometallic reducing agent include organometallic compounds of Group 1, Group 2, Group 12, Group 13 or Group 14 having a hydrocarbon group having 1 to 20 carbon atoms. Examples of such organometallic compounds include organic lithium such as methyl lithium, n-butyl lithium, and phenyl lithium; butyl ethyl magnesium, butyl octyl magnesium, dihexyl magnesium, ethyl magnesium chloride, n-butyl magnesium chloride, and allyl magnesium bromide. Organic magnesium such as dimethyl zinc, diethyl zinc, diphenyl zinc, etc .; Trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum ethoxide, diisobutylaluminum isobutoxide , Ethylaluminum diethoxide, isobutylaluminum diisobutoxide Organoaluminum; tetramethyl tin, tetra (n- butyl) tin, organic tin such as tetraphenyl tin; and the like. Among these, organoaluminum or organotin is preferable. Further, one kind of organometallic reducing agent may be used alone, or two or more kinds may be used in combination at any ratio.

  The ring-opening polymerization reaction is usually performed in an organic solvent. As the organic solvent, a solvent that can dissolve or disperse the ring-opening polymer and its hydrogenated product under predetermined conditions and that does not inhibit the ring-opening polymerization reaction and the hydrogenation reaction can be used. Examples of the organic solvent include aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, Alicyclic hydrocarbon solvents such as tricyclodecane, hexahydroindene and cyclooctane; Aromatic hydrocarbon solvents such as benzene, toluene and xylene; Halogenated aliphatic hydrocarbon solvents such as dichloromethane, chloroform and 1,2-dichloroethane Halogenated aromatic hydrocarbon solvents such as chlorobenzene and dichlorobenzene; nitrogen-containing hydrocarbon solvents such as nitromethane, nitrobenzene and acetonitrile; diethyl ether, tetrahydrofuran and the like Ether solvent; mixed solvent combination thereof; and the like. Among these, as the organic solvent, an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, an alicyclic hydrocarbon solvent, and an ether solvent are preferable. Moreover, an organic solvent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The ring-opening polymerization reaction can be started, for example, by mixing a cyclic olefin monomer, a metal compound represented by the formula (A), and, if necessary, an organometallic reducing agent. The order of mixing these components is not particularly limited. For example, a solution containing a metal compound represented by the formula (A) and an organometallic reducing agent may be mixed with a solution containing a cyclic olefin monomer. Moreover, you may mix the solution containing the cyclic olefin monomer and the metal compound shown by Formula (A) with the solution containing an organometallic reducing agent. Furthermore, you may mix the solution of the metal compound shown by Formula (A) with the solution containing a cyclic olefin monomer and an organometallic reducing agent. When mixing each component, the whole quantity of each component may be mixed at once, and may be mixed in multiple times. Moreover, you may mix continuously over a comparatively long time (for example, 1 minute or more).

  The concentration of the cyclic olefin monomer in the reaction solution at the start of the ring-opening polymerization reaction is preferably 1% by weight or more, more preferably 2% by weight or more, particularly preferably 3% by weight or more, preferably 50% by weight. % Or less, more preferably 45% by weight or less, and particularly preferably 40% by weight or less. By making the concentration of the cyclic olefin monomer at least the lower limit of the above range, productivity can be increased. Moreover, since the viscosity of the reaction liquid after ring-opening polymerization reaction can be made low by setting it as an upper limit or less, the subsequent hydrogenation reaction can be performed easily.

  The amount of the metal compound represented by the formula (A) used for the ring-opening polymerization reaction is desirably set so that the molar ratio of “metal compound: cyclic olefin monomer” falls within a predetermined range. Specifically, the molar ratio is preferably 1: 100 to 1: 2,000,000, more preferably 1: 500 to 1,000,000, particularly preferably 1: 1,000 to 1: 500. , 000. Sufficient polymerization activity can be obtained by setting the amount of the metal compound to be equal to or greater than the lower limit of the above range. Moreover, a metal compound can be easily removed after reaction by setting it as below an upper limit.

  The amount of the organometallic reducing agent is preferably 0.1 mol or more, more preferably 0.2 mol or more, particularly preferably 0.5 mol or more with respect to 1 mol of the metal compound represented by the formula (A). The amount is preferably 100 mol or less, more preferably 50 mol or less, and particularly preferably 20 mol or less. By setting the amount of the organometallic reducing agent to be not less than the lower limit of the above range, the polymerization activity can be sufficiently increased. Moreover, generation | occurrence | production of a side reaction can be suppressed by making it into an upper limit or less.

The polymerization reaction system of the polymer (α) may contain an activity regulator. By using an activity regulator, the ring-opening polymerization catalyst can be stabilized, the reaction rate of the ring-opening polymerization reaction can be adjusted, and the molecular weight distribution of the polymer can be adjusted.
As the activity regulator, an organic compound having a functional group can be used. Examples of such activity regulators include oxygen-containing compounds, nitrogen-containing compounds, and phosphorus-containing organic compounds.

Examples of the oxygen-containing compound include ethers such as diethyl ether, diisopropyl ether, dibutyl ether, anisole, furan, and tetrahydrofuran; ketones such as acetone, benzophenone, and cyclohexanone; esters such as ethyl acetate;
Examples of the nitrogen-containing compound include nitriles such as acetonitrile and benzonitrile; amines such as triethylamine, triisopropylamine, quinuclidine and N, N-diethylaniline; pyridine, 2,4-lutidine, 2,6-lutidine, Pyridines such as 2-t-butylpyridine; and the like.
Examples of the phosphorus-containing compound include phosphines such as triphenylphosphine, tricyclohexylphosphine, triphenylphosphate, and trimethylphosphate; phosphine oxides such as triphenylphosphine oxide; and the like.

An activity regulator may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.
The amount of the activity regulator in the polymerization reaction system of the polymer (α) is preferably 0.01 mol% to 100 mol% with respect to 100 mol% of the metal compound represented by the formula (A).

  The polymerization reaction system of the polymer (α) may contain a molecular weight modifier in order to adjust the molecular weight of the polymer (α). Examples of the molecular weight modifier include α-olefins such as 1-butene, 1-pentene, 1-hexene and 1-octene; aromatic vinyl compounds such as styrene and vinyltoluene; ethyl vinyl ether, isobutyl vinyl ether, allyl glycidyl ether Oxygen-containing vinyl compounds such as allyl acetate, allyl alcohol and glycidyl methacrylate; halogen-containing vinyl compounds such as allyl chloride; nitrogen-containing vinyl compounds such as acrylamide; 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene 1,6-heptadiene, 2-methyl-1,4-pentadiene, non-conjugated dienes such as 2,5-dimethyl-1,5-hexadiene; 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3 Pentadiene, conjugated dienes such as 1,3-hexadiene; and the like.

A molecular weight regulator may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.
The amount of the molecular weight modifier in the polymerization reaction system for polymerizing the polymer (α) can be appropriately determined according to the target molecular weight. The specific amount of the molecular weight modifier is preferably in the range of 0.1 mol% to 50 mol% with respect to the cyclic olefin monomer.

The polymerization temperature is preferably −78 ° C. or higher, more preferably −30 ° C. or higher, preferably + 200 ° C. or lower, more preferably + 180 ° C. or lower.
The polymerization time can depend on the reaction scale. The specific polymerization time is preferably in the range of 1 minute to 1000 hours.

A polymer ((alpha)) is obtained by the manufacturing method mentioned above. The polymer (β) can be produced by hydrogenating the polymer (α).
Hydrogenation of a polymer ((alpha)) can be performed by supplying hydrogen in the reaction system containing a polymer ((alpha)) in presence of a hydrogenation catalyst according to a conventional method, for example. In this hydrogenation reaction, if the reaction conditions are appropriately set, the hydrogenation tacticity usually does not change due to the hydrogenation reaction.

As the hydrogenation catalyst, known homogeneous catalysts and heterogeneous catalysts can be used as hydrogenation catalysts for olefin compounds.
Examples of homogeneous catalysts include transition metals such as cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, and tetrabutoxytitanate / dimethylmagnesium. Catalyst comprising a combination of a compound and an alkali metal compound; dichlorobis (triphenylphosphine) palladium, chlorohydridocarbonyltris (triphenylphosphine) ruthenium, chlorohydridocarbonylbis (tricyclohexylphosphine) ruthenium, bis (tricyclohexylphosphine) benzilidineruthenium (IV) Noble metal complex catalysts such as dichloride and chlorotris (triphenylphosphine) rhodium; It is.
Examples of heterogeneous catalysts include metal catalysts such as nickel, palladium, platinum, rhodium and ruthenium; nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, palladium / Examples thereof include a solid catalyst obtained by supporting the metal such as alumina on a carrier such as carbon, silica, diatomaceous earth, alumina, and titanium oxide.
A hydrogenation catalyst may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The hydrogenation reaction is usually performed in an inert organic solvent. Examples of the inert organic solvent include aromatic hydrocarbon solvents such as benzene and toluene; aliphatic hydrocarbon solvents such as pentane and hexane; alicyclic hydrocarbon solvents such as cyclohexane and decahydronaphthalene; tetrahydrofuran, ethylene glycol dimethyl ether, and the like. Ether solvents; and the like. An inert organic solvent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Further, the inert organic solvent may be the same as or different from the organic solvent used in the ring-opening polymerization reaction. Further, the hydrogenation catalyst may be mixed with the reaction solution for the ring-opening polymerization reaction to perform the hydrogenation reaction.

The reaction conditions for the hydrogenation reaction usually vary depending on the hydrogenation catalyst used.
The reaction temperature of the hydrogenation reaction is preferably −20 ° C. or higher, more preferably −10 ° C. or higher, particularly preferably 0 ° C. or higher, preferably + 250 ° C. or lower, more preferably + 220 ° C. or lower, particularly preferably + 200 ° C. It is as follows. By setting the reaction temperature to be equal to or higher than the lower limit of the above range, the reaction rate can be increased. Moreover, by making it below an upper limit, generation | occurrence | production of a side reaction can be suppressed.

  The hydrogen pressure is preferably 0.01 MPa or more, more preferably 0.05 MPa or more, particularly preferably 0.1 MPa or more, preferably 20 MPa or less, more preferably 15 MPa or less, and particularly preferably 10 MPa or less. By making the hydrogen pressure equal to or higher than the lower limit of the above range, the reaction rate can be increased. Moreover, by making it below an upper limit, special apparatuses, such as a high pressure | voltage resistant reactor, become unnecessary, and installation cost can be suppressed.

The reaction time of the hydrogenation reaction may be set to any time at which a desired hydrogenation rate is achieved, and is preferably 0.1 hour to 10 hours.
After the hydrogenation reaction, the polymer (β) which is a hydrogenated product of the polymer (α) is usually recovered according to a conventional method.

The hydrogenation rate (ratio of hydrogenated main chain double bonds) in the hydrogenation reaction is preferably 98% or more, more preferably 99% or more. The higher the hydrogenation rate, the better the heat resistance of the alicyclic structure-containing polymer.
Here, the hydrogenation rate of the polymer can be measured by ¹ H-NMR measurement at 145 ° C. using orthodichlorobenzene-d ⁴ as a solvent.

Next, a method for producing the polymer (γ) and the polymer (δ) will be described.
The cyclic olefin monomer used for the production of the polymers (γ) and (δ) is selected from the range shown as the cyclic olefin monomer that can be used for the production of the polymer (α) and the polymer (β). Any can be used. Moreover, a cyclic olefin monomer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  In the production of the polymer (γ), any monomer that can be copolymerized with the cyclic olefin monomer in combination with the cyclic olefin monomer can be used as the monomer. Examples of the optional monomer include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-pentene and 1-hexene; aromatic ring vinyl compounds such as styrene and α-methylstyrene. Non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene; Among these, α-olefin is preferable and ethylene is more preferable. Moreover, arbitrary monomers may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The ratio of the amount of the cyclic olefin monomer and the arbitrary monomer is preferably 30:70 to 99: 1, more preferably 50: weight ratio (cyclic olefin monomer: optional monomer). 50-97: 3, particularly preferably 70: 30-95: 5.

  When two or more kinds of cyclic olefin monomers are used, and when a combination of cyclic olefin monomers and arbitrary monomers is used, the polymer (γ) may be a block copolymer or randomly. A copolymer may also be used.

  For the synthesis of the polymer (γ), an addition polymerization catalyst is usually used. Examples of such an addition polymerization catalyst include a vanadium catalyst formed from a vanadium compound and an organoaluminum compound, a titanium catalyst formed from a titanium compound and an organoaluminum compound, a zirconium complex and a zirconium formed from an aluminoxane. And system catalysts. Moreover, an addition polymerization catalyst may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The amount of the addition polymerization catalyst is preferably 0.000001 mol or more, more preferably 0.00001 mol or more, preferably 0.1 mol or less, more preferably 0.01 mol with respect to 1 mol of the monomer. It is as follows.

  The addition polymerization of the cyclic olefin monomer is usually performed in an organic solvent. As an organic solvent, what is selected from the range shown as the organic solvent which can be used for ring-opening polymerization of a cyclic olefin monomer can be used arbitrarily. Moreover, an organic solvent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The polymerization temperature in the polymerization for producing the polymer (γ) is preferably −50 ° C. or more, more preferably −30 ° C. or more, particularly preferably −20 ° C. or more, preferably 250 ° C. or less, more preferably 200 ° C. or lower, particularly preferably 150 ° C. or lower. The polymerization time is preferably 30 minutes or longer, more preferably 1 hour or longer, preferably 20 hours or shorter, more preferably 10 hours or shorter.

The polymer (γ) is obtained by the production method described above. The polymer (δ) can be produced by hydrogenating the polymer (γ).
The hydrogenation of the polymer (γ) can be performed by the same method as described above as the method for hydrogenating the polymer (α).

When the stretched film of the present invention contains a crystalline polymer as the alicyclic structure-containing polymer, the crystallinity thereof is preferably 1% or more, more preferably 2% or more, and even more preferably 3% or more. It is. By having such a high crystallinity, high heat resistance and chemical resistance can be imparted to the stretched film. Although there is no restriction | limiting in the upper limit of the crystallinity degree of the polymer which has crystallinity, Preferably it is 70% or less, More preferably, it is 60% or less, Most preferably, it is 50% or less. When the crystallinity is not more than the above upper limit value, the stretched film can be easily made transparent.
The crystallinity of the polymer can be measured by X-ray diffraction. The degree of crystallinity does not change with line irradiation when the temperature of the film that is normally irradiated with radiation is 80 ° C. or lower. Therefore, the degree of crystallinity measured at the time of the stretched film before treatment remains as it is, and the crystallinity of the line irradiated stretched film It can be.

  The melting point of the crystalline polymer is preferably 200 ° C. or higher, more preferably 230 ° C. or higher, and preferably 290 ° C. or lower. By using a polymer having such a melting point, a stretched film having a further excellent balance between moldability and heat resistance can be obtained.

  The weight average molecular weight (Mw) of the polymer having crystallinity is preferably 1,000 or more, more preferably 2,000 or more, preferably 1,000,000 or less, more preferably 500,000 or less. . A 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 polymer having crystallinity is preferably 1.0 or more, more preferably 1.5 or more, preferably 4.0 or less, more preferably 3.5 or less. Here, Mn represents a number average molecular weight. A 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 crystalline polymer can be measured as a polystyrene equivalent value by gel permeation chromatography (GPC) using tetrahydrofuran as a developing solvent.

  The glass transition temperature Tg of the polymer having crystallinity is not particularly limited, but is usually in the range of 85 ° C. or higher and 170 ° C. or lower.

[1.1.2. (Amorphous alicyclic structure-containing polymer)
The non-crystalline alicyclic structure-containing polymer is a polymer having no crystallinity among the alicyclic structure-containing polymers described above. Examples of the monomer constituting the non-crystalline alicyclic structure-containing polymer are the same as those described above for the monomer constituting the non-crystalline alicyclic structure-containing polymer. Is mentioned. The non-crystalline alicyclic structure-containing polymer is obtained by polymerizing the above-described monomer by a known polymerization method, a polymer having a low degree of syndiotactic stereoregularity, a normal atactic polymer, or It can be produced by making it an isotactic polymer. The mode of polymerization may be either ring-opening polymerization or addition polymerization.

[1.1.3. Block copolymer hydride [D]]
The block copolymer hydride [D], which is an example of the alicyclic structure-containing polymer in the present invention, is obtained 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. The block copolymer hydride [D] may be crystalline or non-crystalline, but is usually non-crystalline.

[1.1.3.1. Polymer block [A]]
The polymer block [A] contains a repeating unit [I] derived from an aromatic vinyl 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] derived from the aromatic vinyl compound 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] derived from the aromatic vinyl compound of the polymer block [A] include the repeating unit [II] derived from a chain conjugated diene and / or other vinyl compounds (that is, vinyl compounds) And a repeating unit [III] derived from a compound which is neither an aromatic vinyl compound nor a chain conjugated diene compound. The content is preferably 2% by weight or less, more preferably 1% by weight or less.

  The heat resistance of the stretched film is controlled by setting the component of the repeating unit [II] derived from the chain conjugated diene and / or the repeating unit [III] derived from other vinyl compound in the polymer block [A] to the lower limit value or less. 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.

[1.1.3.2. Polymer block [B]]
The polymer block [B] is composed mainly of a repeating unit [II] derived from a chain conjugated diene compound, or a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit derived from a chain conjugated diene compound [ 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] into the above range, the block copolymer hydride [D] and the mechanical strength of the stretched film containing the same are obtained. Flexibility can be improved, and heat resistance against a change in phase difference can be improved.

[1.1.3.3. Aromatic vinyl compound
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.

[1.1.3.4. 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.

[1.1.3.5. Other vinyl compounds]
Examples of other vinyl compounds include chain olefin compounds, cyclic olefin compounds, unsaturated cyclic acid anhydrides, unsaturated imide compounds, and the like. These compounds may have a nitrile group, an alkoxycarbonyl group, a hydroxycarbonyl group, or a halogen atom as a substituent.

  Among these, from the viewpoint of hygroscopicity, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-eicosene, C2-C20 chain olefin compounds such as 4-methyl-1-pentene and 4,6-dimethyl-1-heptene; those having 5 to 20 carbon atoms per molecule such as vinylcyclohexane, 4-vinylcyclohexene and norbornene Those that do not contain a polar group such as a cyclic olefin compound are preferred, chain olefin compounds having 2 to 20 carbon atoms per molecule are more preferred, and ethylene and propylene are particularly preferred.

[1.1.3.6. 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 an aromatic vinyl compound as a main component and a chain conjugated diene compound as a main component, or an aromatic vinyl compound and a chain conjugated diene. It can manufacture using the monomer mixture (b) which contains a system 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 an aromatic vinyl compound and a chain conjugated diene compound as main components, the monomer mixture (b) is polymerized to form a copolymer block [B]. It is preferable to continuously supply (b) to the polymerization reaction system little by little. Thereby, even when the polymerization rates of the aromatic vinyl compound and the chain conjugated diene 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.

[1.1.3.7. 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. Specifically, ¹ H-NMR can be performed in the same manner as the measurement of the hydrogenation rate of the polymer (β) and the polymer (δ) described above.

  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 formed stretched film are good.

[1.1.4. Ratio of polymer containing alicyclic structure]
When the stretched film of the present invention comprises a resin containing an alicyclic structure-containing polymer, the proportion of the alicyclic structure-containing polymer in the resin is preferably 50% by weight or more, more preferably 70% by weight or more, Especially preferably, it is 90 weight% or more. By setting the ratio of the alicyclic structure-containing polymer within the range, advantages of the alicyclic structure-containing polymer such as high mechanical strength and good optical characteristics can be obtained.

[1.1.5. (Optional ingredients)
In addition to the alicyclic structure-containing polymer, the resin constituting the pre-treated stretched film can contain any component.
Examples of optional components include crosslinking aids. By containing a crosslinking aid, high Fb / Fa 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 stretched film obtained, 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. Stretched film before treatment)
The pre-treated stretched film used for the production of the stretched film of the present invention is obtained by molding any of the various alicyclic structure-containing polymer resins described above into a film shape and further stretching.

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

  The mode of stretching 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. Moreover, when the film which has phase difference as a product is calculated | required, this phase difference can be obtained easily. On the other hand, when a film having a small retardation is required as a product, for example, by adopting the above-described block copolymer hydride [D] as the alicyclic structure-containing polymer, such a film can be easily obtained. Can be obtained. However, by performing such stretching treatment, the obtained film can be a film that easily undergoes cohesive failure when subjected to a tensile force in the thickness direction. Here, in the present invention, such cohesive failure can be suppressed, so that the peel strength can be increased while enjoying the advantages of the stretched film.

  The dimension of the stretched film before treatment can be appropriately set so that a stretched film that is a product has a desired dimension. In view of production efficiency, the stretched pre-treatment film is preferably a long film. The thickness of the stretched film before treatment is preferably 5 μm or more, more preferably 10 μm or more, and preferably 50 μm or less, more preferably 40 μm or less.

[1.3. Radiation)
The stretched film of the present invention can be obtained by performing a line irradiation step of irradiating the stretched film before treatment with an electron beam or γ-ray. By adopting an electron beam or γ-ray in the beam irradiation step, the irradiation amount can be easily controlled, and the properties of the obtained stretched 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. According to the finding of the present inventor, by performing such a line irradiation step, the strength of the film in the thickness direction can be improved, and the cohesive failure when subjected to the tensile force in the thickness direction can be suppressed. As a result, a stretched film having a high peel strength can be obtained. Although not being bound by a specific theory, it is considered that one reason for the manifestation of such an effect is that a crosslink in the film thickness direction is formed in the film.

  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 amount can be appropriately adjusted so that a desired peel strength can be obtained. Specifically, the absorbed dose is preferably 500 kGy or more, more preferably 6000 kGy or more, and preferably 1500 kGy or less, more preferably 1200 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. (Peel strength)
In the present invention, the peel strength Fa when the surface of the stretched film before treatment and the surface of the adherend are bonded together, and the peel strength when the surface of the stretched film and the surface of the adherend are bonded together Fb satisfies the relationship of Fb ≧ 1.2Fa.

  As an adherend for measuring peel strength, an object to be bonded to the stretched film can be appropriately selected in the use of the stretched film. As the adherend, an alternative material that gives a measurement result equivalent to the measurement result of the peel strength of the bonded product to the object can also be used. For example, when the application of the line irradiation stretched film is a protective film that directly bonds to a polarizer and protects the polarizer in a polarizing plate, the polarizer can be used as an adherend. As an adherend or as an alternative material, the peel strength that appears when the substitute material and the stretched film before treatment are bonded is peeled off when the polarizer and the stretched film before treatment are bonded. The peel strength is equivalent to the strength, and the peel strength expressed when the substitute material and the linear irradiation stretched film are bonded is the peel strength expressed when the polarizer and the linear irradiation stretched film are bonded. A material that can be considered to have a peel strength equivalent to the above can be selected as appropriate. Generally, when a film of an alicyclic structure-containing polymer resin is stretched, it can be a film that easily undergoes cohesive failure when subjected to a tensile force in the thickness direction within the layer. The measurement of the peel strength by such cohesive failure can provide a constant value regardless of the type of adherend if the adherend itself does not stretch (rigid film).

  The peel strength can be measured by preparing a sample film in which a film to be measured and an adherend are bonded and performing a 90-degree peel test on the sample film.

  The film to be measured and the adherend can be bonded using an adhesive as necessary. As the adhesive, in the use of the stretched film, an adhesive used for bonding the stretched film and the adherend or an alternative that gives a result equivalent to the adhesive can be appropriately selected. For example, when the adherend is a polarizer, examples of the adhesive that can be used 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 film to be measured and the adherend are bonded together via an adhesive, and then irradiated with ultraviolet rays as necessary to cure the adhesive layer. The measurement can be performed later. Further, prior to bonding between the film to be measured and the adherend, surface treatment such as corona treatment may be performed as necessary.

  The 90-degree peel test on the sample film is performed by cutting the sample film into a width of 15 mm, bonding the film to be measured to the surface of the slide glass with an adhesive, and 300 mm / min in the normal direction of the surface of the slide glass. This can be done by pulling the adherend at a speed of 5 mm and measuring the magnitude of the pulling force.

  In the stretched film of the present invention, the peel strength Fa when the surface of the stretched film before treatment and the surface of the adherend are pasted, and the surface of the stretched film and the surface of the adherend are pasted together The ratio Fb / Fa of the peel strength Fb is 1.2 or more, preferably 1.25 or more, more preferably 1.3 or more. The upper limit of Fb / Fa is not particularly limited, but may be 20 or less, for example. By having such a relationship, the line-irradiated stretched film can be a film that has high peel strength in addition to mechanical strength and optical properties, and can be usefully used as a protective film in a polarizing plate.

  The dimension of the stretched film of this invention can be suitably set so that it may become a desired dimension as a product. In view of production efficiency, the stretched film of the present invention can be produced as a long film. The thickness of the stretched film of the present invention is preferably 5 μm or more, more preferably 10 μm or more, and preferably 50 μm or less, more preferably 40 μm or less.

[2. Polarizer〕
The stretched film of the present invention has high mechanical strength and good optical properties due to the inclusion of the alicyclic structure-containing polymer, and also has high peel strength from the adherend. In a display device such as an electroluminescence display device, it can be suitably used as a protective film for protecting other layers. In particular, the stretched 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 stretched film of the present invention and a polarizer. In the polarizing plate of the present invention, the stretched 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. As an example of the adhesive which comprises an adhesive bond layer, what was mentioned as an example of the adhesive mentioned above in the case of the measurement of peeling strength can be mentioned.

  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 layers of protective films, both may be a linear irradiation stretched film, that is, the stretched film of the present invention, or only one of them may be a linear irradiation stretched film.

  In the polarizing plate of the present invention, the ratio Fb / Fa of the peel strength Fa between the pre-treated stretched film and the polarizer and the peel strength Fb between the line-irradiated stretched film and the polarizer is 1.2 or more, preferably 1.25 or more, more preferably 1.3 or more. The upper limit of Fb / Fa is not particularly limited, but may be 20 or less, for example. Here, the peel strength Fb of the polarizing plate can be measured in the same manner as the measurement method of the peel strength for the stretched film described above using the polarizing plate as a sample film. Also, the peel strength Fa is the same measurement method as the peel strength measurement method for the stretched film described above by using a pre-treated stretched film instead of the line irradiation stretched film. Can be measured. By having such a relationship between the peel strengths Fa and Fb, a polarizing plate having high mechanical strength and good optical characteristics, and in particular, peeling between the polarizer and the protective film is difficult to occur.

[3. Display device)
The display device of the present invention includes the stretched 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 stretched 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 stretched film of the present invention can be used as, for example, either or both of a light source side polarizing plate and a viewing side polarizing plate, or a protective film on one side. 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 stretched film of the present invention can be provided as a protective film in a polarizing plate used for other applications. 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 stretched film of the present invention can be provided as a protective film for a part of the polarizing plate.

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 and melting point Tm]
A sample heated to 300 ° C. in a nitrogen atmosphere was rapidly cooled with liquid nitrogen, and the temperature was raised at 10 ° C./min using a differential operation calorimeter (DSC) to determine the glass transition temperature Tg and melting point Tm of the sample.
Further, in the case of a block copolymer hydride [D] having two or more Tg, a sample is press-molded to prepare a test piece having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm. JIS-K7244-4 Using a viscoelasticity measuring apparatus (ARES, manufactured by TA Instruments Japan Co., Ltd.), a viscoelastic spectrum is obtained at a temperature rising rate of 5 ° C / min in the range of -100 ° C to + 150 ° C. Measurement was made, and two or more Tg were obtained therefrom. For example, when there are two Tg, the glass transition temperature Tg1 derived from the soft segment from the peak top temperature on the low temperature side of the loss tangent tan δ, and the glass transition temperature Tg2 derived from the hard segment from the peak top temperature on the high temperature side.

[Method for Measuring Hydrogenation Rate of Crystalline Polymer and 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.

[Method of measuring crystallinity of polymer]
The crystallinity of the polymer contained in the film was measured by the X-ray diffraction method.

[Measurement method of peel strength]
As the adherend, a resin film containing a norbornene polymer (Zeonor film, glass transition temperature 160 ° C., thickness 100 μm, manufactured by Nippon Zeon Co., Ltd., which is not particularly subjected to stretching treatment) was prepared. Corona treatment was performed on one side of the measurement target film (stretched film before treatment or linear irradiation stretched film) and one side of the adherend. An adhesive was attached to both the corona-treated surface of the film to be measured and the corona-treated surface of the adherend, and the surfaces to which the adhesive was attached were bonded together. At this time, UV adhesive CRB series (manufactured by Toyochem) was used as the adhesive. Thereafter, using an electrodeless UV irradiation apparatus (manufactured by Heraeus), using a D bulb as a lamp, UV irradiation was performed under conditions of a peak illuminance of 100 mW / cm ² and an integrated light amount of 3000 mJ / cm ² to cure the adhesive. . This obtained the sample film provided with a measuring object film and a to-be-adhered body.

  About the obtained sample film, the 90 degree | times peeling test was implemented. That is, the sample film was cut into a width of 15 mm, and the measurement target film side was bonded to the surface of the slide glass with an adhesive. At this time, a double-sided adhesive tape (manufactured by Nitto Denko Corporation, product number “CS9621”) was used as the adhesive. A high-performance digital force gauge ZP-5N (made by Imada Co., Ltd.) sandwiches the adherend and pulls the adherend at a speed of 300 mm / min in the normal direction of the surface of the slide glass. The thickness was measured as peel strength.

[Reference example: Evaluation of the validity of the peel strength measurement method]
An experiment was conducted to evaluate whether or not the measurement of the peel strength by the measurement method described above reflects the evaluation of the peel strength when the adherend is a polarizer.
A polarizing film and an adhesive were prepared by the same method as described in Example 1 of JP-A-2005-70140. Moreover, the pre-processed stretched film and electron beam irradiation stretched film which were obtained in this-application Example 1 were prepared as a measuring object film. One side of the measurement target film was subjected to corona treatment, and this side was bonded to one surface of the polarizing film via an adhesive. A triacetyl cellulose film was bonded to the other surface of the polarizing film via an adhesive. Then, it was made to dry for 7 minutes at 80 degreeC, the adhesive agent was hardened, and the sample film was obtained. The obtained sample film was subjected to a 90-degree peel test similar to that in [Method of measuring peel strength] described above. As a result, Fa and Fb values similar to those obtained in Example 1 of the present application were obtained. From this, it can be said that the measurement of the peel strength by the measurement method described above reflects the evaluation of the peel strength when the adherend is a polarizer.

[Production Example 1. Production of hydrogenated product of ring-opening polymer of dicyclopentadiene]
The metal pressure-resistant reactor was sufficiently dried and then purged with nitrogen. In this metal pressure-resistant reactor, 154.5 parts of cyclohexane, 42.8 parts of a cyclohexane solution having a concentration of 70% in dicyclopentadiene (endo content 99% or more) (30 parts as the amount of dicyclopentadiene), 1- 1.9 parts of hexene was added and warmed to 53 ° C.

To a solution obtained by dissolving 0.014 part of tetrachlorotungstenphenylimide (tetrahydrofuran) complex in 0.70 part of toluene, 0.061 part of 19% strength diethylaluminum ethoxide / n-hexane solution was added and stirred for 10 minutes. Thus, a catalyst solution was prepared.
This catalyst solution was added to a pressure resistant reactor to initiate a ring-opening polymerization reaction. Then, it was made to react for 4 hours, maintaining 53 degreeC, and the solution of the ring-opening polymer of dicyclopentadiene was obtained.
The number average molecular weight (Mn) and weight average molecular weight (Mw) of the resulting ring-opened polymer of dicyclopentadiene are 8,750 and 28,100, respectively, and the molecular weight distribution (Mw / Mn) determined from these. Was 3.21.

  To 200 parts of the resulting ring-opening polymer solution of dicyclopentadiene, 0.037 part of 1,2-ethanediol was added as a terminator, heated to 60 ° C. and stirred for 1 hour to stop the polymerization reaction. I let you. To this, 1 part of hydrotalcite-like compound (“KYOWARD (registered trademark) 2000” manufactured by Kyowa Chemical Industry Co., Ltd.) was added, heated to 60 ° C., and stirred for 1 hour. Then, 0.4 parts of filter aid (“Radiolite (registered trademark) # 1500” manufactured by Showa Chemical Industry Co., Ltd.) was added, and the PP pleated cartridge filter (“TCP-HX” manufactured by ADVANTEC Toyo Co., Ltd.) was used. The solution was filtered off.

  100 parts of cyclohexane is added to 200 parts of a ring-opening polymer solution of dicyclopentadiene after filtration (30 parts of polymer amount), 0.0043 part of chlorohydridocarbonyltris (triphenylphosphine) ruthenium is added, and hydrogen is added. The hydrogenation reaction was carried out at 6 MPa and 180 ° C. for 4 hours. Thereby, the reaction liquid containing the hydrogenated product of the ring-opening polymer of dicyclopentadiene was obtained. In this reaction solution, a hydrogenated product was deposited to form a slurry solution.

  The hydrogenated product and the solution contained in the reaction solution are separated using a centrifuge, dried under reduced pressure at 60 ° C. for 24 hours, and the hydrogenated product of a ring-opening polymer of dicyclopentadiene having crystallinity. 28.5 parts were obtained. The hydrogenation rate of this hydrogenated product was 99% or more, the glass transition temperature (Tg) was 95 ° C., and the melting point (Tm) was 262 ° C.

[Example 1]
(1-1. Preparation of resin)
To 100 parts of the hydrogenated product of the ring-opening polymer of dicyclopentadiene obtained in Production Example 1, an antioxidant (tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) was added. ) Propionate] Methane; 1.1 parts of “Irganox (registered trademark) 1010” manufactured by BASF Japan Ltd.) were mixed to obtain a resin as a film material.

(1-2. Production of stretched film before treatment)
The resin obtained in (1-1) was put 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 original film (thickness 50 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: 30rpm
Thereafter, the raw film is cut into a size of 100 mm × 100 mm, and using a small biaxial stretching machine (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the edges of the four sides of the film are held with clips, and a stretching temperature of 110 ° C. Fixed end uniaxial stretching was continuously performed at a stretching ratio of 2 to obtain a stretched film before treatment. At this time, the crystallinity of the polymer in the pre-treated stretched film was 4%. Peel strength Fa was measured using a part of the obtained pre-treated stretched film as a sample.

(1-3. Production and evaluation of electron beam irradiation stretched film)
Using an electron beam irradiation apparatus (manufactured by I. Electron Beam Co., Ltd.), the stretched film before treatment obtained in (1-2) has an absorbed dose of 1200 kGy under conditions of an electron beam irradiation atmosphere oxygen concentration of 300 ppm or less and an acceleration voltage of 150 kV. Were irradiated with an electron beam to obtain an electron beam irradiated stretched film. The peel strength Fb of the electron beam irradiated stretched film was measured, and Fb / Fa was determined to be 1.5.

[Example 2]
Except for the following items, an electron beam irradiated stretched film was obtained and evaluated in the same manner as in Example 1.
-In (1-2), after fixed end uniaxial stretching, it heat-processed on 170 degreeC and 30 second conditions in the state which hold | gripped the 4 sides of a film. Thereby, the crystallinity of the polymer in the film was 25%. This film was used as a pre-treated stretched film and subjected to the measurement of peel strength Fa and the subsequent step (1-3).
-In (1-3), the absorbed dose was changed to 800 kGy.

Example 3
Except for the following items, an electron beam irradiated stretched film was obtained and evaluated in the same manner as in Example 1.
-In (1-2), after fixed end uniaxial stretching, it heat-processed on 170 degreeC and 30 second conditions in the state which hold | gripped the 4 sides of a film. Thereby, the crystallinity of the polymer in the film was 25%. This film was used as a pre-treated stretched film and subjected to the measurement of peel strength Fa and the subsequent step (1-3).

Example 4
(4-1. Production of stretched film before treatment)
Pellets of a resin containing a cycloolefin polymer (a norbornene polymer resin having a glass transition temperature of 126 ° C., manufactured by Nippon Zeon Co., Ltd.) were dried at 100 ° C. for 5 hours. Thereafter, the dried resin pellets were fed into a single screw extruder. The resin was melted in an extruder, then passed through a polymer pipe and a polymer filter, extruded from a T-die onto a casting drum, and cooled. As a result, an original film having a thickness of 50 μm and a width of 500 mm was obtained. The raw film is cut into a size of 100 mm × 100 mm, and using a small biaxial stretching machine (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the edges of the four sides of the film are held with clips, a stretching temperature of 145 ° C., and a stretching ratio. The fixed-end uniaxial stretching was continuously performed at 2 times to obtain a stretched film before treatment. Peel strength Fa was measured using a part of the obtained pre-treated stretched film as a sample.

(4-2. Production and evaluation of electron beam irradiated stretched film)
Using an electron beam irradiation apparatus (manufactured by I. Electron Beam Co., Ltd.), the stretched film before treatment obtained in (4-1) has an absorbed dose of 800 kGy under conditions of an electron beam irradiation atmosphere oxygen concentration of 300 ppm or less and an acceleration voltage of 150 kV. Were irradiated with an electron beam to obtain an electron beam irradiated stretched film. The peel strength Fb of the electron beam irradiated stretched film was measured and Fb / Fa was determined to be 1.3.

Example 5
(5-1. 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.

(5-2. Block copolymer hydride [D])
The polymerization reaction solution obtained in (5-1) 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.

(5-3. Preparation of resin)
Mixing 100 parts of the block copolymer hydride [D] obtained in (5-2) with 5 parts of a crosslinking aid (Tyke (manufactured by Nippon Kasei Co., Ltd.)), a resin serving as a film material is obtained. Obtained.

(5-4. Production of electron beam irradiated stretched film)
An electron beam was obtained in the same manner as in (1-2) to (1-3) of Example 1 except that the resin obtained in (5-3) was used instead of the resin obtained in (1-1). An irradiated stretched film was produced and evaluated.

Example 6
(6-1. 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.

(6-2. Block copolymer hydride [D])
(5-2) of Example 5 except that the polymerization reaction solution containing the block copolymer [C] was replaced with the one obtained in (6-1) instead of the one obtained in (5-1). 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 ° C., and a Tg2 of 137 ° C.

(6-3. Production of electron beam irradiated stretched film)
(1-2) to (1-3) of Example 1 except that the block copolymer hydride [D] obtained in (6-2) was used instead of the resin obtained in (1-1). In the same manner as above, an electron beam irradiated stretched film was produced and evaluated.

Example 7
(7-1. 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 point was 99.5% (measured by gas chromatography, the same applies hereinafter). 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.

(7-2. Block copolymer hydride [D])
(5-2) of Example 5 except that the polymerization reaction solution containing the block copolymer [C] was replaced by the polymerization reaction solution obtained in (7-1) instead of the one obtained in (5-1). 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.

(7-3. Production of electron beam irradiated stretched film)
(1-2) to (1-3) of Example 1 except that the block copolymer hydride [D] obtained in (7-2) was used instead of the resin obtained in (1-1). In the same manner as above, an electron beam irradiated stretched film was produced and evaluated.

[Comparative Example 1]
An electron beam irradiated stretched film was produced and evaluated in the same manner as in Example 2 except that the dose was changed to 400 kGy in (1-3).

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

  From the results of Table 1, when using any of a crystalline alicyclic structure-containing polymer, a non-crystalline alicyclic structure-containing polymer, and an alicyclic structure-containing polymer that is a block copolymer hydride. Also, it can be seen that a stretched film that can be used as a protective film was obtained by obtaining high Fb / Fa by line irradiation.

Claims (9)

A stretched film formed by irradiating a stretched pre-treatment film containing an alicyclic structure-containing polymer with an electron beam or γ-ray,
The peel strength Fa when the surface of the stretched film before treatment and the surface of the adherend are bonded, and the peel strength Fb when the surface of the stretched film and the surface of the adherend are bonded, A stretched film that satisfies the relationship of Fb ≧ 1.2 Fa.   The stretched film according to claim 1, wherein the alicyclic structure-containing polymer is crystalline and has a crystallinity of 1% or more.   The stretched film according to claim 1, wherein the alicyclic structure-containing polymer is amorphous. The alicyclic structure-containing polymer is
Two or more polymer blocks [A] per molecule mainly composed of a repeating unit [I] derived from an aromatic vinyl compound;
It is composed of a repeating unit [II] derived from a chain conjugated diene compound, or one or more polymer blocks [B] per molecule mainly composed of a combination of the repeating unit [I] and the repeating unit [II]. A block copolymer hydride [D] obtained by hydrogenating a block copolymer [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 stretched film according to claim 1. It is a manufacturing method of the stretched film of any one of Claims 1-4, Comprising:
The manufacturing method including the line | wire irradiation process of irradiating an electron beam or a gamma ray to the stretched film before a process containing an alicyclic structure containing polymer.   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 500 kGy or more and 1500 kGy or less.   A polarizing plate provided with the stretched film of any one of Claims 1-4, and a polarizer.   A display apparatus provided with the stretched film of any one of Claims 1-4.