JP4925759B2 - Norbornene polymer, film, polarizing plate and liquid crystal display device using norbornene polymer - Google Patents

Description

  The present invention relates to norbornene-based polymers, optical films using norbornene-based polymers (particularly various functional films such as retardation films, viewing angle widening films, antireflection films used in plasma displays, polarizing plate protective films), polarizing films The present invention relates to a plate and a liquid crystal display device.

A film of a norbornene-based addition polymer obtained by vinyl polymerization of a norbornene-based compound (hereinafter referred to as a norbornene-based polymer) is characterized by a high thickness direction retardation (Rth), and thus can be applied to a negative C plate. (Patent Document 1). Furthermore, by stretching this, the main chain of the norbornene-based polymer is aligned in the stretching direction and expresses retardation (Re), and can be applied to a negative biaxial retardation plate. That is, the norbornene-based polymer film is promising as a retardation film having high Re and Rth. In particular, a preferable value can be taken as a retardation film of a VA (vertical alignment) liquid crystal display device.

On the other hand, retardation films of liquid crystal display devices in recent years have characteristics in which Re and Rth values are continuously different not only at specific Re and Rth values at a certain wavelength, but also at wavelengths in the visible light region (400 nm to 700 nm) ( Chromatic dispersion) is required. For example, a retardation film of a vertical alignment (VA) liquid crystal display device is required to have reverse wavelength dispersion characteristics in which the Re value increases as the wavelength increases. For example, when Re at wavelengths of 450 nm, 590 nm, and 630 nm is Re ₄₅₀ , Re ₅₉₀ , and Re ₆₃₀ , it is required that Re ₄₅₀ <Re ₅₉₀ <Re ₆₃₀ .

In general, it is effective to introduce a component having a long absorption wavelength in order to fluctuate the wavelength dispersion. However, Patent Document 2 only describes a polymer having a phenyl group introduced so far.

International Publication WO2004 / 049011 Pamphlet International Publication WO2004 / 007587 Pamphlet

In the study conducted by the present inventors, although the wavelength dispersibility of the above-mentioned norbornene polymer film containing a phenyl group is improved, the degree is small and insufficient to improve the color appearance of the liquid crystal display device. It turned out to be. Therefore, a norbornene-based polymer film that can increase the degree of wavelength dispersion is desired.

  In order to solve the above-mentioned problems, the present inventor considered that introducing an aromatic compound component having a longer absorption wavelength is effective for the problems of the present invention. Surprisingly, when an aromatic compound hydrogen-releasing product having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 is introduced into the norbornene-based polymer. The present inventors have found that the wavelength dispersion characteristics of the birefringence of the film can be dramatically improved. Further, the present inventors have found that the stereochemistry of the hydrogen-leaved product of this aromatic compound is the key to the positive / negative (forward wavelength or reverse wavelength) of wavelength dispersion. That is, the inventors have found that the chromatic dispersion characteristic of birefringence becomes the reverse chromatic dispersion characteristic by exo-linking an aromatic compound component to the norbornene unit, resulting in the present invention.

Means for solving the above problems are as follows.
(1) Substitution including a hydrogen detachment of an aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 [mol ⁻¹ dm ³ cm ⁻¹ ] A norbornene-based polymer comprising at least one repeating unit derived from a norbornene-based compound having at least one group.
(2) The norbornene polymer according to (1), wherein the repeating unit derived from the norbornene compound is represented by the following general formula (I).
(Wherein R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or 300 nm to 400 nm) A substituent containing a hydrogen-elimination product of an aromatic compound having a maximum absorption wavelength and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000, at least one of the substituents containing the hydrogen-elimination product is there.)
(3) The norbornene polymer according to (2), wherein among R ¹ , R ² , R ^3, and R ⁴ , substituents other than the substituent containing the hydrogen-eliminating body are each a hydrogen atom or an alkyl group. .
(4) The norbornene-based polymer according to (2), wherein one or two of R ¹ , R ² , R ^3, and R ⁴ is a substituent containing the hydrogen detachment product.
(5) The norbornene-based polymer according to any one of (1) to (4), wherein a substituent containing the hydrogen-eliminating substance is substituted with an exo linkage.
(6) The aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and having a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 is a 2 to 4 cyclic aromatic compound (1) to (5 The norbornene-based polymer according to any one of 1).
(7) The norbornene-based polymer according to any one of (1) to (6), further including at least one repeating unit represented by the following general formula (II).
(Wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ are each a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or —L— O—CO—R ⁹ (L is a single bond or an alkylene group having 1 to 10 carbon atoms, and R ⁹ is an alkyl group having 1 to 10 carbon atoms), at least one of which is —L—O—. CO-R ⁹ )
(8) The norbornene polymer according to (7), wherein R ⁹ is an alkyl group having 1 to 5 carbon atoms.
(9) The norbornene-based polymer according to any one of (2) to (8), comprising 3 to 50% of a repeating unit represented by the general formula (I) in a polymerization composition ratio.
(10) The norbornene-based polymer according to (8) or (9), which is formed only from the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II).
(11) A film comprising the norbornene polymer according to any one of (1) to (10).
(12) The film according to (11), wherein the difference ΔRe = Re ₆₃₀ −Re ₄₅₀ between the in-plane retardation Re ₄₅₀ at a wavelength of ₄₅₀ nm and the in-plane retardation Re _{630 at} a wavelength of 630 nm satisfies 10 nm ≦ ΔRe ≦ 100 nm.
(13) The film according to (11) or (12), wherein the in-plane retardation Re ₅₉₀ at a wavelength of 590 nm satisfies 30 nm ≦ Re ₅₉₀ ≦ 200 nm.
(14) A polarizing plate comprising a polarizing film and the film described in any one of (11) to (13).
(15) A liquid crystal display device comprising the polarizing plate according to (14).

  Hereinafter, embodiments of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

[Norbornene polymer]
The norbornene polymer in the present invention is a homopolymer obtained by addition polymerization of one kind of norbornene compound or a copolymer obtained by addition polymerization of two or more kinds of norbornene compounds.

The norbornene-based polymer in the present invention has a maximum absorption wavelength at 300 nm to 400 nm in order to effectively change the wavelength dispersion characteristic of birefringence, and the molar extinction coefficient at the maximum absorption wavelength is 10 to 100,000. It contains a substituent containing a hydrogen eliminator of an aromatic compound (hereinafter sometimes simply referred to as “substituent containing a hydrogen eliminator”). The number of substituents including the hydrogen eliminator per repeating unit derived from a norbornene-based compound is not particularly limited, and is preferably 1 or 2 and more preferably 1 in terms of synthesis. In the norbornene polymer of the present invention, the repeating unit derived from a norbornene compound having a substituent containing the hydrogen eliminator constituting the polymer may include a plurality of types, and the number of types is particularly For example, one type can also be used suitably.

Since the main chain of the polymer is composed of hydrocarbons, the absorption is 300 nm or less. Even in a norbornene polymer having a substituent such as a carbonyl group in the side chain, the absorption of the carbonyl group is 300 nm or less.

In this specification, the maximum absorption wavelength is an aromatic having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 [mol ⁻¹ dm ³ cm ⁻¹ ]. This refers to the maximum point of the absorption peak when the compound is dissolved in methylene chloride at an appropriate concentration (if insoluble, it is dissolved with hexane, heptane, etc.), and the absorption wavelength is measured at 25 ° C. with a normal UV measuring instrument. The unit of the molar extinction coefficient is [mol ⁻¹ dm ³ cm ⁻¹ ], but unless otherwise specified, the unit of the molar extinction coefficient is defined in this. The maximum absorption wavelength is not necessarily the maximum absorption wavelength. There may be multiple local maxima.

An aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 has at least one maximum absorption wavelength at 300 to 400 nm. A compound having a peak of 300 nm or less and a tail of 300 nm or more does not correspond to this. Therefore, benzene, acetoxybenzene, methoxybenzene, phenol, styrene and the like are not the aromatic compounds.

In addition, although the aromatic compound which has a maximum absorption wavelength in 300 nm-400 nm has a maximum absorption wavelength in 300 nm-400 nm, you may have maximum wavelength absorption out of this range. However, when the maximum absorption wavelength is 400 nm or more, the norbornene-based polymer tends to be yellow and the film tends to be colored. Therefore, it is preferable that there is no maximum absorption wavelength at 400 nm or more.

As the molar extinction coefficient of an aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm is larger, the effect of changing the wavelength dispersion characteristic of birefringence tends to be larger. The aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm according to the present invention has a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000, but the effect is remarkable when the molar extinction coefficient is 100 or more. It is. Therefore, the aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm according to the present invention preferably has a molar extinction coefficient of 100 to 100,000, and more preferably has a molar extinction coefficient of 120 to 100,000. More preferably, it has a molar extinction coefficient of 130 to 100,000.

Specific examples of the aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 include the following compounds, but the present invention is not limited thereto. .

Among these, 2 to 4 cyclic aromatic compounds (for example, naphthalene, anthracene, phenanthrene, pyrene, chrysene, etc.) have a maximum absorption wavelength of 300 to 400 nm and a molar absorption coefficient of 100 to 10,000, and 400 nm or more. Is preferable because it has no absorption.

The norbornene-based polymer of the present invention contains an aromatic compound hydrogen detachment having a maximum absorption wavelength at 300 nm to 400 nm. There are two types of hydrogen detachment bodies, ie, 1 hydrogen detachment body and 2 hydrogen detachment body. In the present invention, 1 hydrogen detachment body is preferable. 1 When a hydrogen-eliminating substance exists as a side chain of a norbornene-based polymer, there are a direct connection method and a connection method via a spacer. When connected via a spacer, the state of the aromatic ring becomes random, and the birefringence wavelength dispersion of the polymer film is not preferable from the viewpoint of control. Therefore, it is preferable that the spacer is short. On the other hand, when directly connected, the state of the aromatic ring becomes more rigid, which is preferable from the viewpoint of birefringence wavelength dispersion control of the polymer film.

Preferred examples of the repeating unit derived from the norbornene compound according to the present invention include repeating units represented by the following general formula (I).
Formula (I)
(Wherein R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or 300 nm to 400 nm, respectively. Having a maximum absorption wavelength, and having a molar absorption coefficient at the maximum absorption wavelength of 10 to 100,000, a substituent containing a hydrogen-elimination product of an aromatic compound, at least one of the substituents containing the hydrogen-elimination product .)

R ¹ , R ² , R ^3, and R ⁴ include aromatic hydrogen desorbents having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000. The group other than the substituent is preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. It is an alkyl group or a phenyl group, more preferably a hydrogen atom or a phenyl group, and most preferably a hydrogen atom. As the number of substitutions, in order to obtain the effect of the present invention, it is better that many substituents containing a hydrogen-elimination product of an aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm are substituted. It is preferable that the number of substituents containing a hydrogen-elimination product of an aromatic compound having a maximum absorption wavelength is one or two, and more preferably one. For example, preferably, one is a hydrogen atom and the remaining two are a hydrogen atom or a phenyl group, more preferably both are hydrogen atoms.

At least one of R ¹ , R ² , R ³ and R ⁴ is a hydrogen atom of an aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000. The substituent includes a leaving body (hereinafter sometimes referred to as “substituent A”), and the substituent A has the same meaning as described above, and the preferred range is also the same. That is, a preferred range of an aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000, a preferred range of the molar extinction coefficient, and the aromatic compound A preferred embodiment and the like relating to a connection method (a direct connection method and a connection method via a spacer) between the hydrogen desorber and norbornane are also synonymous.

In the general formula (I), the substituent A is preferably an exo linkage. In the case of exo-linking, the aromatic ring of the substituent A is in a state orthogonal to the main chain direction, and the reverse wavelength dispersion of the norbornene-based polymer film containing the aromatic ring is effectively exhibited (particularly, the connection between the hydrogen-eliminating substance and norbornane). The effect is significant when the method is a direct connection method). Accordingly, 50% to 100% of the repeating units represented by the general formula (I) are preferably exo-linked, more preferably 70 to 100% are exo-linked, and 100% are exo-linked. Is more preferable.

The norbornene-based compound containing the substituent A can be obtained by a Diels-Alder reaction between cyclopentadiene and the corresponding olefin. On the other hand, norbornadiene and AX (A halide) can be coupled in the presence of a palladium catalyst to synthesize an exo form.

Specific examples of the repeating unit represented by the general formula (I) are shown below, but the present invention is not limited thereto.

  The norbornene-based polymer containing the repeating unit represented by the general formula (I) may contain other norbornene-based compounds without departing from the gist of the present invention. In addition, the content of the repeating unit represented by the general formula (I) in the norbornene-based polymer of the present invention is a polymerization composition ratio of the repeating unit represented by the general formula (I) according to the type of the substituent A and the like. However, it can be suitably adjusted in the range of more than 0% and not more than 100%, preferably more than 0 and not more than 80%, more preferably more than 0 and not more than 60%, further preferably 3 to 50%, more preferably 3 to 40%. Is particularly preferred. When the content of the repeating unit represented by formula (I) is small, the effect of controlling the birefringence wavelength dispersion of the norbornene polymer of the present invention tends to be small, and when the content is large, the effect tends to be large.

Further, since the repeating unit represented by the general formula (I) has a rigid aromatic ring, the polymer has disadvantages in film production such as low solubility and too high glass transition point. In order to eliminate these problems, it is preferable to copolymerize at least one norbornene-based compound containing a polar group. Examples of the copolymer component of the norbornene-based polymer containing a polar group include a repeating unit represented by the general formula (III).
Formula (III)

In the formula, w, x, y, and z are hydrogen, alkyl group, aryl group, halogen, (CH ₂ ) _n OH, (CH ₂ ) _n COOH, (CH ₂ ) _n COOR ′, and (CH ₂ ), respectively. _n OR ′, (CH ₂ ) _n OCOR ′, (CH ₂ ) _n OCOOR ′, (CH ₂ ) _n OR ′, (CH ₂ ) _n O (CH ₂ ) _n OH, w, x, y, z At least one of (CH ₂ ) _n OH, (CH ₂ ) _n COOH, (CH ₂ ) _n COOR ′, (CH ₂ ) _n OR ′, (CH ₂ ) _n OCOR ′, (CH ₂ ) _{n OCOOR ', (CH 2) n} OR', represent _{(CH 2) n O (CH} 2) n OH, n is an integer of 0, R 'represents an alkyl group having 1 to 10 carbon atoms; m represents 0 or 1;

As for this monomer, a monomer with m = 0 can be obtained by Diels-Alder reaction of cyclopentadiene and the corresponding olefin. Furthermore, the monomer of m = 1 can be obtained by making this react with a cyclopentadiene.

Specific examples of the repeating unit represented by formula (III) are shown below, but the present invention is not limited thereto.

From the viewpoint of lowering the glass transition point, m is preferably m = 0. Among them, a repeating unit represented by the general formula (II) described later can be preferably exemplified.
In particular, the norbornene-based polymer of the present invention preferably comprises only a repeating unit represented by the general formula (I) and a repeating unit represented by the general formula (II) described later. “Only” in this case does not depart from the gist of the present invention except that it contains no components other than the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II). Other components may be included within the range. For example, reaction residues such as monomers constituting these repeating units and additives usually used in polymerization may be contained. In addition, the suitable range of the polymerization composition ratio of the repeating unit represented by the general formula (I) at that time can be appropriately adjusted in the same manner as described above, and is preferably greater than 0 and 80% or less, preferably greater than 0 and 60 % Or less is more preferable, 3 to 50% is more preferable, and 3 to 40% is particularly preferable.

(Wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ are each a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or —L— O—CO—R ⁹ (L is a single bond or an alkylene group having 1 to 10 carbon atoms, and R ⁹ is an alkyl group having 1 to 10 carbon atoms), at least one of which is —L—O—. CO-R ⁹ )

Of R ⁵ , R ⁶ , R ⁷ and R ⁸ , the substituent other than —L—O—CO—R ⁹ is preferably a hydrogen atom or an alkyl group which may have a substituent. A group or a hydrogen atom is more preferred, and a hydrogen atom is still more preferred.
L is preferably a single bond or an alkylene group having 1 to 5 carbon atoms, more preferably a single bond or an alkylene group having 1 or 2 carbon atoms, and even more preferably a single bond or a methylene group.

R ⁹ preferably has a small carbon number from the viewpoint of reducing the photoelasticity of the film, but is preferably large from the viewpoint of lowering the glass transition point of the polymer. Considering both points, R ⁹ preferably has 1 to 6 carbon atoms, more preferably 3 to 5 carbon atoms, and still more preferably a propyl group, a butyl group, or a pentyl group. In addition, among R ⁵ , R ⁶ , R ⁷ and R ⁸ , the number of substitution of —L—O—CO—R ⁹ is preferably 1 or 2 and more preferably 1 in terms of synthesis. As other substituents in that case, the same ones as described above can be preferably exemplified.

The stereochemistry in the unit of norbornene polymer containing —L—O—CO—R ⁹ (acyloxymethyl group) is not particularly defined. However, in general, the stereochemistry of the raw material monomer is endo / exo≈80 / 20, and by using this, it is generally end rich.

The repeating unit represented by the general formula (II) is obtained, for example, by polymerization of an acyloxymethyl-containing norbornene compound as described below, and the acyloxymethyl-containing norbornene compound includes cyclopentadiene and a corresponding allyl compound. Can be obtained by the Diels-Alder reaction.

Examples of preferred norbornene-based polymers containing the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II) are shown below, but the present invention is not limited thereto. Absent.

The norbornene polymer of the present invention preferably has a polystyrene-equivalent number average molecular weight of 10,000 to 1,000,000 as measured by gel permeation chromatogram using tetrahydrofuran as a solvent, and is preferably 50,000. More preferably, it is ˜500,000. The weight average molecular weight in terms of polystyrene is preferably 15,000 to 1,500,000, more preferably 70,000 to 700,000. When the number average molecular weight in terms of polystyrene is 10,000 or more and the weight average molecular weight is 15,000 or more, the fracture strength tends to be more preferable, the number average molecular weight in terms of polystyrene is 1,000,000 or less, and the weight average molecular weight. If it is 1,500,000 or less, the molding processability as a sheet tends to be improved, and the solution viscosity tends to be low when it is used as a cast film or the like, and it tends to be easy to handle. The molecular weight distribution (weight average molecular weight / number average molecular weight) is preferably 1.1 to 5.0, more preferably 1.1 to 4.0, and still more preferably 1.1 to 3.5. By setting the molecular weight distribution of the norbornene-based polymer within the above range, the norbornene-based polymer solution (dope) is likely to be uniform, and a good film can be easily produced.

The norbornene-based polymer of the present invention can be obtained by the following polymerization method using the monomer obtained by the above method.

[Pd (CH ₃ CN) ₄ ] [BF ₄ ] ₂ , di-μ-chloro-bis- (6-methoxybicyclo [2.2.1] hept-2-ene-endo-5σ, 2π) as a polymerization catalyst -Pd (hereinafter abbreviated as "I") and methylalumoxane (MAO), I and AgBF ₄ , I and AgSbF ₆ , [(η ³ -allyl) PdCl] ₂ and AgSbF ₆ , [(η ³ -allyl) PdCl] ₂ and AgBF ₄ , [(η ³ -crotyl) Pd (cyclooctadiene)] [PF ₆ ], [(η ³ -allyl) Pd (η ⁵ -cyclopentadienyl)] ₂ and tricyclohexylphosphine Dimethylanilinium tetrakispentafluorophenylborate or trityltetrakispentafluorophenylborate, palladium bisacetylacetonate, tricyclohexylphosphine and dimethyla Nilinium tetrakispentafluorophenylborate, [(η ³ -allyl) PdCl] ₂ and tricyclohexylphosphine and tributylallyltin or allylmagnesium chloride and dimethylanilinium tetrakispentafluorophenylborate, [(η ⁵ -cyclopentadienyl) Ni (methyl) (triphenylphosphine)] and trispentafluorophenylborane, [(η ³ -crotyl) Ni (cyclooctadiene)] [B ((CF ₃ ) ₂ C ₆ H ₄ ) ₄ ], [NiBr ( NPMe ₃ )] ₄ and MAO, Ni (Octoate) ₂ and MAO, Ni (Octoate) ₂ and B (C ₆ F ₅ ) ₃ and AlEt ₃ , Ni (Octoate) ₂ and [ph ₃ C] [B (C ₆ F _{5) 4]} and Ali-Bu _3, Co (neodecanoate) and the periodic table of the MAO such as 8 Of Ni, Pd, using a catalyst to form a cationic complex or cation complex such as Co, in a range of 20 to 150 ° C. in a solvent obtained by alone or copolymerizing a monomer.
The monomer can be allowed to react in the reaction vessel from the beginning, or a method of gradually feeding the monomer can be employed.
Solvents include cycloaliphatic hydrocarbon solvents such as cyclohexane, cyclopentane and methylcyclopentane; aliphatic hydrocarbon solvents such as pentane, hexane, heptane and octane; aromatic hydrocarbon solvents such as toluene, benzene and xylene; dichloromethane Halogenated hydrocarbon solvents such as 1,2-dichloroethylene and chlorobenzene; polar solvents such as ethyl acetate, butyl acetate, γ-butyrolactone, propylene glycol dimethyl ether and nitromethane.
As another synthesis method, the method described in Macromolecules, 1996, 29, 2755, Macromolecules, 2002, 35, 8969, International Patent Publication WO 2004/7564 is also preferably used.

[Norbornene polymer film]
The norbornene polymer film of the present invention refers to a film containing the norbornene polymer of the present invention.

[Use of norbornene polymer film]
The norbornene-based polymer of the present invention is useful as a film material. In particular, films prepared using the polymer include substrates for liquid crystal display elements, light guide plates, polarizing films, retardation films, liquid crystal backlights, liquid crystal panels, OHP films, transparent conductive films, and the like. Suitable for optical use film. The norbornene-based polymer represented by the general formula (I) is suitably used for optical materials such as optical discs, optical fibers, lenses, and prisms, electronic components, medical devices, containers, and the like.

[Method for producing norbornene polymer film]
The film of this invention contains the norbornene-type polymer containing the repeating unit represented by general formula (I), and can be produced by forming into a film from this polymer. There are two methods for film formation: hot melt film formation and solution film formation, and both are applicable, but in the present invention, a solution film formation method capable of obtaining an excellent surface film is used. preferable. The solution casting method is described below.

(Solution casting method)
(Preparation of dope)
First, a solution (dope) of the polymer used for film formation is prepared. The organic solvent used for the preparation of the dope is not particularly limited as long as it can be dissolved, cast, and formed into a film, and the purpose can be achieved. For example, chlorinated solvents such as dichloromethane and chloroform, chain hydrocarbons having 3 to 12 carbon atoms (hexane, octane, isooctane, decane, etc.), cyclic hydrocarbons (cyclopentane, cyclohexane, decalin, etc.), aromatic carbonization Hydrogen (benzene, toluene, xylene, etc.), ester (ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, pentyl acetate, etc.), ketone (acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone) , Cyclohexanone and methylcyclohexanone), ether (diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, Preferably the solvent selected from over like Le and phenetole). Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. The preferable boiling point of the organic solvent is 35 ° C to 200 ° C. The solvent used for the preparation of the solution can be used by mixing two or more kinds of solvents in order to adjust the solution properties such as drying property and viscosity. Further, as long as the solvent is dissolved in the mixed solvent, a poor solvent is added. It is also possible.

  A preferred poor solvent can be appropriately selected. When a chlorinated organic solvent is used as the good solvent, alcohols can be preferably used. Alcohols may preferably be linear, branched or cyclic, and among them, saturated aliphatic hydrocarbons are preferred. The hydroxyl group of the alcohol may be any of primary to tertiary. As the alcohol, fluorine-based alcohol is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like. Among the poor solvents, particularly monovalent alcohols have an effect of reducing the peeling resistance and can be preferably used. Particularly preferred alcohols vary depending on the good solvent to be selected, but considering the drying load, alcohols having a boiling point of 120 ° C. or lower are preferable, monohydric alcohols having 1 to 6 carbon atoms are more preferable, and alcohols having 1 to 4 carbon atoms Can be particularly preferably used.

  A particularly preferred mixed solvent for preparing the dope is a combination in which dichloromethane is the main solvent and at least one alcohol selected from methanol, ethanol, propanol, isopropanol, or butanol is a poor solvent.

  For the preparation of the dope, a method of stirring and dissolving at room temperature, and stirring the polymer at room temperature to swell the polymer, cooling to -20 ° C to -100 ° C, and cooling to 20 ° C to 100 ° C again to dissolve. There are a dissolution method, a high-temperature dissolution method that dissolves at a temperature equal to or higher than the boiling point of the main solvent in a closed container, and a method that dissolves at a high temperature and high pressure up to the critical point of the solvent. The viscosity of the dope is preferably in the range of 1 to 500 Pa · s at 25 ° C., more preferably in the range of 5 to 200 Pa · s.

  Prior to casting, it is preferable to filter off foreign matters such as undissolved matter, dust, and impurities using a suitable filter medium such as a wire mesh or flannel. The viscosity immediately before film formation may be in a range that allows casting during film formation, and is preferably adjusted to a range of 5 Pa · s to 1000 Pa · s, more preferably in a range of 15 Pa · s to 500 Pa · s. The range of 30 Pa · s to 200 Pa · s is more preferable. In addition, although the temperature at this time will not be specifically limited if it is the temperature at the time of the casting, Preferably it is -5-70 degreeC, More preferably, it is -5-35 degreeC.

(Additive)
The film of the present invention may contain additives other than the polymer, and such additives may be added at any stage of the process for producing the film. Additives can be selected depending on the application, such as deterioration inhibitors, UV inhibitors, retardation (optical anisotropy) regulators, fine particles, peeling accelerators, infrared absorbers, etc. Can be mentioned. These additives may be solid or oily. In the case of film production by the solution casting method, the addition time may be added at any time during the dope preparation process, or an additive is added to the final preparation process of the dope preparation process. You may go. In the case of film production by the melting method, it may be added at the time of resin pellet production, or may be kneaded at the time of film production. The amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ.

  From the viewpoint of preventing film deterioration, a deterioration (oxidation) inhibitor is preferably used. For example, 2,6-di-tert-butyl, 4-methylphenol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol), pentaerythrityl-tetrakis [3- (3,5- Phenolic or hydroquinone antioxidants such as di-tert-butyl-4-hydroxyphenyl) propionate can be added. Furthermore, phosphorus antioxidants such as tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite It is preferable to The addition amount of the antioxidant is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the polymer.

  From the viewpoint of preventing deterioration of the polarizing plate or the liquid crystal, an ultraviolet absorber is preferably used. As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specific examples of the ultraviolet absorber preferably used in the present invention include, for example, hindered phenol compounds, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex salts Compound etc. are mentioned. The addition amount of these ultraviolet light inhibitors is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio with respect to the norbornene polymer.

  In order to improve the slipperiness of the film surface, fine particles (mat agent) are preferably used. By using this, unevenness is imparted to the film surface, that is, by increasing the roughness of the film surface (matization), the blocking between the films can be reduced. The presence of fine particles in the film or on at least one surface of the film significantly improves the adhesion between the polarizer and the film during polarizing plate processing. The matting agent used in the present invention is inorganic fine particles, for example, fine particles having an average particle size of 0.05 μm to 0.5 μm, preferably 0.08 μm to 0.3 μm, more preferably 0.1 μm to 0 μm. .25 μm. In the fine particles, silicon dioxide, silicone and titanium dioxide are preferable as the inorganic compound, fluororesin, nylon, polypropylene and chlorinated polyether are preferable as the polymer compound, silicon dioxide is more preferable, and surface treatment with organic matter is performed. Silicon is more preferred.

  In order to reduce the peeling resistance of the film, a peeling accelerator is preferably used. As preferred release agents, phosphate ester surfactants, carboxylic acid or carboxylate surfactants, sulfonic acid or sulfonate surfactants, and sulfate ester surfactants are effective. A fluorine-based surfactant in which part of the hydrogen atoms bonded to the hydrocarbon chain of the surfactant is substituted with fluorine atoms is also effective. The addition amount of the release agent is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass, and further preferably 0.1 to 0.5% by mass with respect to the norbornene-based polymer.

(Film production)
For the method and equipment for producing the film of the present invention, the same solution casting film forming method and solution casting film forming apparatus as those used for producing a known cellulose triacetate film are preferably used. The dope prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation.

  JP 2000-301555, JP 2000-301558, JP 7-032391, JP 3-193316, JP 5-086212, JP 62-037113, JP 2-276607, The cellulose acylate film forming techniques described in JP-A-55-014201, JP-A-2-111511, and JP-A-2-208650 can be preferably employed in the present invention.

(Multilayer casting)
The dope may be cast as a single layer liquid on a smooth band or drum as a metal support, or a plurality of dopes of two or more layers may be cast. In the case of multilayer casting, the inner and outer thicknesses are not particularly limited, but preferably the outer thickness is 1 to 50% of the total film thickness, and more preferably 2 to 30%.

(Casting)
As a solution casting method, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method using a doctor blade in which the dope once cast on the metal support is adjusted with a blade is used. Alternatively, there is a method using a reverse roll coater that adjusts with a reverse rotating roll, and a method using a pressure die is preferable. The temperature of the dope used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all of the steps may be the same or different at various points in the step. When they are different, it is preferable that the temperature is a desired temperature immediately before casting.

(Dry)
Drying of the dope on the metal support in the production of the film is generally accomplished by applying hot air from the surface side of the metal support (eg, drum or band), that is, the surface of the web on the metal support, drum or A method of applying hot air from the back side of the band, contacting the temperature controlled liquid from the back side opposite the dope casting surface of the band or drum, and heating the drum or band by heat transfer to control the surface temperature Although there are methods, the back surface liquid heat transfer method is preferable. The surface temperature of the metal support before casting may be any number as long as it is not higher than the boiling point of the solvent used for the dope. However, in order to promote drying and to lose fluidity on the metal support, the temperature should be set to 1 to 10 ° C. lower than the boiling point of the lowest boiling solvent. Is preferred. This is not the case when the casting dope is cooled and peeled off without drying.

(Peeling)
When peeling a dry film from a metal support, if the peeling resistance (peeling load) is large, the film is irregularly stretched in the film forming direction, resulting in uneven optical anisotropy. In particular, when the peeling load is large, a portion stretched stepwise in the film forming direction and a portion unstretched are alternately generated, resulting in a distribution in retardation. When loaded in a liquid crystal display device, the line or strip becomes uneven. In order not to cause such a problem, it is preferable to set the peeling load of the film to 0.25 N or less per 1 cm of the film peeling width. The peeling load is more preferably 0.2 N / cm or less, further preferably 0.15 N or less, and particularly preferably 0.10 N or less. When the peeling load is 0.2 N / cm or less, even in a liquid crystal display device in which unevenness is likely to appear, no unevenness due to peeling is observed at all, which is particularly preferable. As a method of reducing the peeling load, there are a method of adding a release agent as described above and a method of selecting a solvent composition to be used. The preferable residual volatile content concentration at the time of peeling is 5 to 60% by mass. 10-50 mass% is further more preferable, and 20-40 mass% is especially preferable. Peeling with a high volatile content is preferable because the drying rate can be increased and the productivity is improved. On the other hand, when the volatile content is high, the strength and elasticity of the film are small, and the film is cut or stretched against the peeling force. Further, the self-holding force after peeling is poor, and deformation, wrinkles and nicks are likely to occur. It also causes distribution in the retardation.

(Stretching)
When the film produced by the solution casting method is further stretched, it is preferably carried out in a state where the solvent still remains in the film immediately after peeling. The purpose of stretching is (1) to obtain a film having excellent flatness without wrinkles and deformation, and (2) to increase the in-plane retardation of the film. When stretching is performed for the purpose of (1), stretching is performed at a relatively high temperature, and stretching is performed at a low magnification from 1% to 10% at most. A stretch of 2-5% is particularly preferred. When stretching for the purposes of both (1) and (2) or only for the purpose of (2), the film is stretched at a relatively low temperature and a stretch ratio of 5 to 150%.

  The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. The birefringence of the retardation film for a VA liquid crystal cell or OCB (Optically Compensatory Bend) liquid crystal cell is preferably such that the refractive index in the width direction is larger than the refractive index in the length direction. Therefore, it is preferable to stretch more in the width direction.

  The thickness of the finished film (after drying) of the present invention varies depending on the purpose of use, but is usually in the range of 20 to 500 μm, preferably in the range of 30 to 150 μm, particularly 40 to 110 μm for liquid crystal display devices. It is preferable.

[Characteristics of film]
In the film of the present invention, the difference ΔRe = Re ₆₃₀ −Re ₄₅₀ between the in-plane retardation Re ₄₅₀ at a wavelength of ₄₅₀ nm and the in-plane retardation Re _{630 at} a wavelength of 630 nm preferably satisfies 10 nm ≦ ΔRe ≦ 100 nm. ΔRe ≦ 80 nm is more preferable, and 10 nm ≦ ΔRe ≦ 60 nm is most preferable.
The preferred optical properties of the film of the present invention vary depending on the application of the film. Below, the preferable range in each use of in-plane retardation (Re) and thickness direction retardation (Rth) which converted the thickness of the film into 80 micrometers is shown.

  When used as a polarizing plate protective film: Re is preferably 0 nm ≦ Re ≦ 5 nm, and more preferably 0 nm ≦ Re ≦ 3 nm. Rth is preferably 0 nm ≦ Rth ≦ 50 nm, more preferably 0 nm ≦ Rth ≦ 35 nm, and particularly preferably 0 nm ≦ Rth ≦ 10 nm.

  When used as a retardation film: The range of Re and Rth varies depending on the type of retardation film and there are various needs, but 0 nm ≦ Re ≦ 100 nm and 0 nm ≦ Rth ≦ 400 nm are preferable. In the TN mode, 0 nm ≦ Re ≦ 20 nm, 40 nm ≦ Rth ≦ 80 nm, and in the VA mode, 20 nm ≦ Re ≦ 80 nm and 80 nm ≦ Rth ≦ 400 nm are more preferable. In particular, the preferable range in the VA mode is 30 nm ≦ Re ≦ 75 nm, 120 nm ≦ Rth. ≦ 250 nm, when compensating with one retardation film, 50 nm ≦ Re ≦ 75 nm, 180 nm ≦ Rth ≦ 250 nm, when compensating with two retardation films, 30 nm ≦ Re ≦ 50 nm, 80 nm ≦ Rth ≦ 140 nm. These are preferred embodiments as a VA mode compensation film in terms of color shift at the time of black display and the viewing angle dependency of contrast.

  The film of the present invention can achieve desired optical characteristics by appropriately adjusting process conditions such as copolymerization ratio, additive type and amount, stretch ratio, residual volatile content at the time of peeling.

In this specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at a wavelength λ, respectively. Re (λ) is measured by making light with a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).

When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotating axis) (if there is no slow axis, any in-plane The light is incident at a wavelength of λ nm from the inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction of the rotation axis of KOBRA 21ADH or WR calculates based on the measured retardation value, the assumed average refractive index, and the input film thickness value.

In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing the sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (1) and (2).
Note:
The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
In formula (1), nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. .
Rth = ((nx + ny) / 2-nz) x d --- Formula (2)
In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optic axis, Rth (λ) is calculated by the following method.
Rth (λ) is from -50 ° to + 50 ° with respect to the normal direction of the film, with Re (λ) as the slow axis (determined by KOBRA 21ADH or WR) in the plane and the tilt axis (rotation axis). In each of the 10 degree steps, light of wavelength λ nm is incident from each inclined direction and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or Calculated by WR.
In the above measurement, as the assumed value of the average refractive index, the values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of the main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). By inputting these assumed values of average refractive index and film thickness, KOBRA 21ADH or WR calculates nx, ny, and nz. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

In the case of using the film of the present invention as a protective film for polarizing plate, the value of the photoelastic is ^{0.5 × 10 -13 ~9.0 × 10 -13} [cm 2 / dyn], moisture permeability values However, it is preferable that the value (converted assuming the thickness of the film as 80 μm) is 180 to 435 [g / cm ² 24 h]. The value of photoelasticity is more preferably 0.5 × 10 ^{−13 to} 7.0 × 10 ⁻¹³ [cm ² / dyn], and 0.5 × 10 ^{−13 to} 5.0 × 10 ⁻¹³ [ More preferably, it is cm ² / dyn]. In addition, the value of moisture permeability (however, the value obtained by converting the film thickness to 80 μm) is more preferably 180 to 400 [g / cm ² 24h], and 180 to 350 [g / cm ² 24h]. Is more preferable. When the film of the present invention has the above-described properties, when it is used as a protective film for a polarizing plate, it is possible to reduce a decrease in performance due to the influence of humidity.

[Polarizer]
The polarizing plate of the present invention has at least the film of the present invention and a polarizer. Usually, a polarizing plate has a polarizer and two protective films disposed on both sides thereof. The film of the present invention can be used as both or one protective film. A normal cellulose acetate film or the like may be used for the other protective film. Examples of the polarizer include an iodine polarizer, a dye polarizer using a dichroic dye, and a polyene polarizer. The iodine polarizer and the dye polarizer are generally produced using a polyvinyl alcohol film. When the film of the present invention is used as a polarizing plate protective film, the film is subjected to a surface treatment as described later, and then the film-treated surface and a polarizer are bonded together using an adhesive. Examples of the adhesive used include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latexes such as butyl acrylate, and gelatin. The polarizing plate is composed of a polarizer and a protective film that protects both surfaces of the polarizer, and is further constructed by laminating a protective film on one surface of the polarizing plate and a separate film on the opposite surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the contact bonding layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate. The film is preferably bonded so that the transmission axis of the polarizer and the slow axis of the film coincide with each other.

(Film surface treatment)
In the present invention, the surface of the film is preferably surface-treated in order to improve the adhesion between the polarizer and the protective film. As for the surface treatment, any method may be used as long as the adhesiveness can be improved. Preferred examples of the surface treatment include glow discharge treatment, ultraviolet irradiation treatment, corona treatment, and flame treatment. The glow discharge treatment here refers to so-called low temperature plasma that occurs under low pressure gas. In the present invention, plasma treatment under atmospheric pressure is also preferable. In addition, the details of the glow discharge treatment are described in US Pat. No. 3,462,335, US Pat. No. 3,761,299, US Pat. No. 4,072,769, and British Patent No. 891469. A method described in JP-A-59-556430 in which the discharge atmosphere gas composition is changed to only the gas species generated in the container by subjecting the polyester support itself to a discharge treatment after the start of discharge is also used. In addition, the method described in Japanese Patent Publication No. 60-16614, in which the surface temperature of the film is set to 80 ° C. to 180 ° C. when performing the vacuum glow discharge treatment, can also be applied.

  As for the degree of surface treatment, the preferred range varies depending on the type of surface treatment, but as a result of the surface treatment, the contact angle with the pure water on the surface of the protective film subjected to the surface treatment is preferably less than 50 °. . The contact angle is more preferably 25 ° or more and less than 45 °. When the contact angle with the pure water on the surface of the protective film is in the above range, the adhesive strength between the protective film and the polarizing film becomes good.

(adhesive)
When laminating a polarizer made of polyvinyl alcohol and the surface-treated film of the present invention, it is preferable to use an adhesive containing a water-soluble polymer. Water-soluble polymers preferably used for the adhesive include N-vinyl pyrrolidone, acrylic acid, methacrylic acid, maleic acid, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, vinyl alcohol, methyl vinyl ether, vinyl acetate. , Acrylamide, methacrylamide, diacetone acrylamide, vinyl imidazole, etc., homopolymers or polymers having ethylenically unsaturated monomers as constituents, polyoxyethylene, polyoxypropylene, poly-2-methyloxazoline, methylcellulose, hydroxyethylcellulose , Hydroxypropylcellulose gelatin, and the like. Of these, PVA and gelatin are preferred in the present invention. The thickness of the adhesive layer is preferably 0.01 to 5 μm after drying, and more preferably 0.05 to 3 μm.

(Antireflection layer)
It is preferable to provide a functional film such as an antireflection layer on the protective film disposed on the opposite side of the polarizing plate from the liquid crystal cell. In particular, in the present invention, at least a light scattering layer and a low refractive index layer are laminated in this order on the protective film, or an intermediate refractive index layer, a high refractive index layer, and a low refractive index layer are arranged in this order on the protective film. A laminated antireflection layer is preferably used.

(Light scattering layer)
The light scattering layer is formed for the purpose of contributing to the film light diffusibility due to surface scattering and / or internal scattering and hard coat properties for improving the scratch resistance of the film. Therefore, it is formed including a binder for imparting hard coat properties, matte particles for imparting light diffusibility, and inorganic fillers for increasing the refractive index, preventing crosslinking shrinkage, and increasing the strength as necessary. The The thickness of the light scattering layer is preferably from 1 to 10 μm, more preferably from 1.2 to 6 μm, from the viewpoint of imparting hard coat properties and from the viewpoint of curling and suppressing deterioration of brittleness.

(Other layers of antireflection layer)
Further, a hard coat layer, a forward scattering layer, a primer layer, an antistatic layer, an undercoat layer, a protective layer, and the like may be provided.

(Hard coat layer)
The hard coat layer is provided on the surface of the support in order to impart physical strength to the protective film provided with the antireflection layer. In particular, it is preferably provided between the support and the high refractive index layer. The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of a light and / or heat curable compound. The curable functional group is preferably a photopolymerizable functional group, and the hydrolyzable functional group-containing organometallic compound is preferably an organic alkoxysilyl compound.

(Antistatic layer)
In the case of providing an antistatic layer, it is preferable to impart conductivity with a volume resistivity of 10 ⁻⁸ (Ωcm ⁻³ ) or less. The use of hygroscopic substances, water-soluble inorganic salts, certain surfactants, cationic polymers, anionic polymers, colloidal silica, etc. can give a volume resistivity of 10 ⁻⁸ (Ωcm ⁻³ ). There is a problem that dependency is large, and sufficient conductivity cannot be secured at low humidity. Therefore, a metal oxide is preferable as the conductive layer material.

[Liquid Crystal Display]
The film of the present invention, a retardation film comprising the film, and a polarizing plate using the film can be used for liquid crystal cells and liquid crystal display devices in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal, AFLC) Various display modes such as HAN (Hybrid Aligned Nematic) have been proposed. Of these, the OCB mode or the VA mode can be preferably used.

The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. However, Example 7 and Example 17 are reference examples.

[Norbornene compounds]
Among the norbornene compounds as the raw materials for the norbornene polymer used in the present invention, 5-norbornene-2-yl acetate (NBOCOCH ₃ ) can be purchased from Aldrich, and norbornene carboxylic acid methyl ester (NBCOOCH ₃ ) can be purchased from Tokyo Chemical Industry. When the peak purity was measured by gas chromatography, NBOCOCH ₃ had a purity of 99.0%, an endo / exo ratio of 78/22, NBCOOCH ₃ had a purity of 98.5%, and an endo / exo ratio of 49/51. It was. Other norbornene compounds were produced as in the following synthesis examples.

Synthesis Example 1 Synthesis of 5-acetoxymethyl-2-norbornene (NBCH ₂ OCOCH ₃ ) 1094 g of dicyclopentadiene (manufactured by Wako Pure Chemical Industries, Ltd.), 1772 g of allyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.) and hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.) 1 g was charged into an autoclave, and the air gap was replaced with nitrogen. The mixture was stirred for 9 hours at an internal temperature of 180 ° C. in a closed system (rotational speed = 300 rpm). The reaction mixture was filtered and the volatile components were evaporated. The residue was subjected to precision distillation (column length = 120 cm, column packing = Propak, reflux ratio = 10/1, pressure = 10 mmHg, top temperature = 89 ° C.) to obtain colorless and transparent NBCH ₂ OCH ₃ . . When the peak purity was measured by gas chromatography, the purity was 99.9% and the endo / exo ratio was 83/17.

Synthesis Example 2 Synthesis of 5-butyloxymethyl-2-norbornene (NBCH ₂ OCOC ₃ H ₇ ) The same procedure as in Synthesis Example 1 was conducted except that allyl acetate was changed to allyl butyrate (manufactured by Aldrich). Clear NBCH ₂ OCOC ₃ H ₇ was obtained. When the peak purity was measured by gas chromatography, the purity was 99.1% and the endo / exo ratio was 80/20.

Synthesis Example 3 5-Hexyloxymethyl-2-norbornene (NBCH ₂ OCOC ₅ H ₁₁ ) Synthesis Example 1 was repeated except that allyl acetate was changed to allyl hexanoate (manufactured by Wako Pure Chemical Industries, Ltd.) in Synthesis Example 1. A colorless and transparent NBCH ₂ OCOC ₅ H ₁₁ was obtained. When the peak purity was measured by gas chromatography, the purity was 99.0% and the endo / exo ratio was 79/21.

Synthesis Example 4 Synthesis of endo-rich-phenylnorbornene (endorich-PhNB) 674.0 g of dicyclopentadiene (manufactured by Wako Pure Chemical Industries, Ltd.), 508.0 g of styrene (manufactured by Wako Pure Chemical Industries, Ltd.) and 1 g of hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.) Was charged into an autoclave and the air gap was replaced with nitrogen. The mixture was stirred for 8 hours at an internal temperature of 180 ° C. in a closed system (rotational speed = 300 rpm). The reaction mixture was flash-distilled to remove residual cyclopentadiene, styrene, and polymer, thereby obtaining a preferential PhNB. This was subjected to precision distillation to obtain colorless and transparent endorich-PhNB. The obtained colorless and transparent liquid was subjected to gas chromatography to measure the peak purity. As a result, the purity was 98.5% and the endo / exo ratio was 78/22.

Synthesis Example 5 Synthesis of exo-phenylnorbornene (exo-PhNB) 100.0 g of iodobenzene (manufactured by Wako Pure Chemical Industries, Ltd.), 200 mL of norbornadiene (manufactured by Tokyo Chemical Industry Co., Ltd.), 200 mL of dimethylformamide, 225 mL of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) 48 ml of formic acid (purity 99%, manufactured by Wako Pure Chemical Industries, Ltd.) and 3.4 g of palladium dichlorobistriphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged and reacted at an internal temperature of 50 ° C. for 3 hours. This was separated and extracted with ethyl acetate / water, and the organic layer was taken out. Dried over magnesium sulfate, filtered and evaporated volatiles. The residue was subjected to column chromatography and distilled with hexane. The residue obtained by concentration was subjected to vacuum distillation (3 mmHg / 95 ° C.) to obtain colorless and transparent exo-PhNB. The obtained colorless and transparent liquid was subjected to gas chromatography to measure its peak purity. As a result, the purity was 98.0%, and the endo / exo ratio was 0/100.

Synthesis Example 6 Synthesis of exo-1-naphthylnorbornene (exo-1-NaphNB) 1-iodonaphthalene (manufactured by Aldrich) 123.0 g, dimethylformamide (manufactured by Wako Pure Chemical Industries) 200 mL, norbornadiene (manufactured by Tokyo Chemical Industry Co., Ltd.) 170 mL Then, 270 mL of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.), 58 mL of formic acid (99%, manufactured by Wako Pure Chemical Industries, Ltd.) and 5.16 g of palladium dichlorobistriphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged and stirred at 60 ° C. for 3 hours. The reaction solution was extracted with ethyl acetate / water, and the organic layer was dried over magnesium sulfate. This was filtered and evaporated. The residue was subjected to column chromatography (developing solvent: hexane), and the resulting solution was evaporated. This was distilled under reduced pressure (3 mmHg / 150-155 ° C.). The obtained colorless and transparent liquid exo-1-NaphNB was subjected to gas chromatography and its peak purity was measured. The purity was 99.0% and the endo / exo ratio was 0/100.

Synthesis Example 7 Synthesis of exo-1-pyrenylnorbornene (exo-PyrNB) 1-bromopyrene (manufactured by Tokyo Chemical Industry Co., Ltd.) 102.1 g, dimethyformamide (manufactured by Wako Pure Chemical Industries, Ltd.) 180 ml, norbornadiene (manufactured by Tokyo Chemical Industry Co., Ltd.) 112 ml, 180 mL of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.), 40 mL of formic acid (99%, manufactured by Wako Pure Chemical Industries, Ltd.) and 3.0 g of palladium dichlorobistriphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged and stirred at 80 ° C. for 4 hours. The reaction solution was extracted with ethyl acetate / water, and the organic layer was dried over magnesium sulfate. This was filtered and evaporated. The residue was subjected to column chromatography (developing solvent: hexane), and the fraction containing the target product was concentrated and recrystallized. White crystalline exo-PyrNB was obtained.

[Synthesis of norbornene polymers]
Example 1 Synthesis of P-1 45 mL of purified toluene, 36.0 g of NBCH ₂ OCOC ₅ H ₁₁ and 7.9 g of exo-NaphNB were charged into a reaction vessel. Subsequently, a solution obtained by reacting 12.4 mg of palladium bisacetoacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 11.3 mg of tricyclohexylphosphine (manufactured by Strem Co.) with 5 mL of toluene was added. Subsequently, 61 mg of dimethylanilinium tetrakispentafluorophenyl borate (manufactured by Strem Co.) dissolved in 5 mL of methylene chloride was added. The solution was stirred at 90 ° C. for 6 hours. The obtained solution was reprecipitated in methanol to obtain P-1 as a white solid. This was vacuum-dried at 110 ° C. for 6 hours.

The above P-1 was dissolved in deuterated dichloromethane, and ¹ HNMR was measured. From the comparison of the integrated value of the peak (hydrogen of naphthyl group) appearing at 6.5 to 8.5 ppm and the integrated value of the peak (methylene hydrogen bonded to an acetoxy group) appearing at 3.0 to 4.5 ppm, the copolymerization ratio is 73/27.

The obtained polymer was dissolved in tetrahydrofuran, and the molecular weight was measured by gel permeation chromatography (GPC). In terms of polystyrene, the weight average molecular weight (Mw) was 504800, and the number average molecular weight was 104800.

Example 2 Synthesis of P-2 200 mL of purified toluene, 31.2 g of NBCH ₂ OCOC ₅ H ₁₁ and 11.8 g of exo-NaphNB were charged into a reaction vessel. Next, a solution obtained by reacting 6.6 mg of palladium bisacetoacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 5.9 mg of tricyclohexylphosphine (manufactured by Strem Co.) with 5 mL of toluene was added. Subsequently, 49 mg of dimethylanilinium tetrakispentafluorophenylborate (manufactured by Strem Co.) dissolved in 5 mL of methylene chloride was added. The solution was stirred at 90 ° C. for 6 hours. The obtained solution was reprecipitated in methanol to obtain a white solid P-2. This was vacuum-dried at 110 ° C. for 6 hours.

As described above, when ¹ HNMR was measured, the copolymerization ratio was 36/64. When the molecular weight was measured by GPC, Mw was 450300 and Mn was 103100 in terms of polystyrene.

Example 3 P-3
In Example 1, the same synthesis was carried out using NBCH ₂ OCOC ₃ H ₇ in an equimolar amount instead of NBCH ₂ OCOC ₅ H ₁₁ to obtain P-2. The copolymerization ratio was 25/75. When the molecular weight was measured by GPC, Mw was 473400 and Mn was 113400 in terms of polystyrene.

Example 4 Synthesis of P-4 A similar synthesis was performed using an equimolar amount of NBCH ₂ OCOCH ₃ instead of NBCH ₂ OCOC ₅ H ₁₁ in Example 1, to obtain P-4. The copolymerization ratio was 24/76. When the molecular weight was measured by GPC, Mw was 540500 and Mn was 132400 in terms of polystyrene.

Example 5 Synthesis of P-5 The same synthesis was performed in Example 1 using an equimolar amount of NBCOOCH ₃ instead of NBCH ₂ OCOC ₅ H ₁₁ to obtain P-5. The copolymerization ratio was 45/55. When the molecular weight was measured by GPC, Mw was 200300 and Mn was 52100 in terms of polystyrene.

Example 6 Synthesis of P-6 P-6 was obtained in the same manner as in Example 1, except that an equimolar amount of NBOCOCH ₃ was used instead of NBCH ₂ OCOC ₅ H ₁₁ . The copolymerization ratio was 45/55. When the molecular weight was measured by GPC, Mw was 227500 and Mn was 83100 in terms of polystyrene.

Example 7 Synthesis of P-7 200 mL of purified toluene, 51.8 g of exo-NaphNB and 11.2 g of 1-octene (manufactured by Wako Pure Chemical Industries, Ltd.) were charged into a reaction vessel. Next, a solution obtained by reacting 2 mg of palladium bisacetoacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2 mg of tricyclohexylphosphine (manufactured by Strem Co.) with 5 mL of toluene was added. Subsequently, 30 mg of dimethylanilinium tetrakispentafluorophenylborate (manufactured by Strem Co.) dissolved in 5 mL of methylene chloride was added. The solution was stirred at 90 ° C. for 4 hours. The obtained solution was reprecipitated in methanol to obtain white solid P-7. This was vacuum-dried at 110 ° C. for 6 hours. When the molecular weight was measured by GPC, Mw was 340500 and Mn was 793000 in terms of polystyrene.

Example 8 Synthesis of P-8 80 mL of purified toluene, 35.1 g of NBCH ₂ OCOC ₅ H ₁₁ and 2.3 g of exo-PyrNB were charged into a reaction vessel. Next, a solution obtained by reacting 10.5 mg of palladium bisacetolacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 9.5 mg of tricyclohexylphosphine (manufactured by Strem Co.) with 5 mL of toluene was added. Subsequently, 60 mg of dimethylanilinium tetrakispentafluorophenyl borate (manufactured by Strem) dissolved in 5 mL of methylene chloride was added. The solution was stirred at 90 ° C. for 6 hours. The obtained solution was reprecipitated in methanol to obtain a white solid P-8. This was vacuum-dried at 110 ° C. for 6 hours.

As described above, when ¹ HNMR was measured, the copolymerization ratio was 95/5. When the molecular weight was measured by GPC, Mw was 490200 and Mn was 110500 in terms of polystyrene.

Example 9 Synthesis of P-9 80 mL of purified toluene, 35.2 g of NBCH ₂ OCOC ₅ H ₁₁ and 7.0 g of exo-PyrNB were charged into a reaction vessel. Subsequently, a solution obtained by reacting 10.7 mg of palladium bisacetoacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10.3 mg of tricyclohexylphosphine (manufactured by Strem Co.) with 5 mL of toluene was added. Subsequently, 60 mg of dimethylanilinium tetrakispentafluorophenyl borate (manufactured by Strem) dissolved in 5 mL of methylene chloride was added. The solution was stirred at 90 ° C. for 6 hours. The obtained solution was reprecipitated in methanol to obtain a white solid P-9. This was vacuum-dried at 110 ° C. for 6 hours.

As described above, ¹ HNMR was measured, and the copolymerization ratio was 84/16. When the molecular weight was measured by GPC, Mw was 520300 and Mn was 122000 in terms of polystyrene.

Example 10 Synthesis of P-10 The same synthesis was performed in Example 9 by using an equimolar amount of NBCH ₂ OCOCH ₃ instead of NBCH ₂ OCOC ₅ H ₁₁ to obtain P-10. The copolymerization ratio was 15/85. When the molecular weight was measured by GPC, Mw was 493400 and Mn was 74500 in terms of polystyrene.

Comparative Example 1 Synthesis of PC-1 60 mL of purified toluene, 26.9 g of NBCH ₂ OCOC ₅ H ₁₁ and 6.9 g of endorcih-NBPh were charged into a reaction vessel. Subsequently, a solution obtained by reacting 7.1 mg of palladium bisacetoacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 7.6 mg of tricyclohexylphosphine (manufactured by Strem Co.) with 10 mL of toluene was added. Subsequently, 49 mg of dimethylanilinium tetrakispentafluorophenylborate (manufactured by Strem Co.) dissolved in 5 mL of methylene chloride was added. The solution was stirred at 90 ° C. for 6 hours. Since the viscosity of the solution increased as the reaction proceeded, toluene was added as appropriate. The resulting solution was reprecipitated in methanol to give a white solid. This was vacuum-dried at 110 ° C. for 6 hours.

As described above, when ¹ HNMR was measured, the copolymerization ratio was 27/73. When the molecular weight was measured by GPC, Mw was 492,500 and Mn was 108400 in terms of polystyrene.

Comparative Example 2 Synthesis of PC-2 In Comparative Example 1, the same synthesis was performed using equimolar amount of exo-NBPh instead of endorcih-NBPh to obtain PC-2. This copolymerization ratio was 27/73. When the molecular weight was measured by GPC, Mw was 118900 and Mn was 523100 in terms of polystyrene.

In the above P-1 to 10 and PC-1 to PC-2, a 1-hydrogen leaving body of benzene, naphthalene and pyrene is used as a long wave component. A methylene chloride solution of 10 mg / L of benzene, naphthalene and pyrene was prepared and measured at 25 ° C. with a UV measuring machine UV-2550 manufactured by Shimadzu Corporation. The maximum absorption of benzene was not detected at a wavelength of 300 nm or more. On the other hand, the maximum absorption wavelength of naphthalene and pyrene was detected at 300 nm to 400 nm. Four maximum absorption wavelengths were detected for pyrene. The main maximum absorption wavelength and molar extinction coefficient are shown in the table below.

(Example 11)
(Film measurement and Re measurement of film)
30 g of polymer P-1 was dissolved in 120 g of methylene chloride, and this was filtered under pressure. The obtained dope was cast on an A3 large hydrophobic glass plate using an applicator. This was dried in a 25 ° C. closed system for 1 minute, followed by drying in a blow dryer at 40 ° C. for 15 minutes. The film was peeled off from the glass plate and sandwiched between stainless steel frames, which were dried in a dryer at 100 ° C. for 30 minutes and in a dryer at 133 ° C. for 30 minutes to obtain a transparent film F-1.

The thickness of F-1 was measured at an arbitrary portion with a digital micrometer at three points, and the average value was taken. Front retardation at wavelengths of 450 nm, 590 nm, and 630 nm was measured based on the above-described method in a room adjusted to 25 ° C. and 60% RH. A converted value of 80 μm was obtained from this value and the actually measured film thickness. The front retardation of the unstretched film converted into a film thickness of 80 μm at wavelengths of 450 nm, 590 nm, and 630 nm is Re ₄₅₀ , Re ₅₉₀ , Re ₆₃₀ , ΔRe = Re ₆₃₀ −Re _450, and the results are shown in Table 2.

(Production of stretched film and Re measurement)
F-1 was cut into 5 cm length and 5 cm width. This was stretched 60% at a temperature of 250 ° C. using an automatic stretching machine manufactured by Imoto Seisakusho to obtain a stretched film F-1 ′. The thickness of the film and the front retardation at wavelengths of 450 nm, 590 nm, and 630 nm were measured, and a converted value of 80 μm was determined from this value and the actually measured film thickness. Table 2 shows the results of the front retardation Re ₄₅₀ , Re ₅₉₀ , Re ₆₃₀ , and ΔRe = Re ₆₃₀ −Re ₄₅₀ at wavelengths of 450 nm, 590 nm, and 630 nm of a stretched film having a thickness of 80 μm.

(Examples 12 to 20)
A film was produced from the polymers P-2 to 10 in the same manner as in Example 11 to obtain films F-2 to 10. The film thickness and the front retardation at wavelengths of 450 nm, 590 nm, and 630 nm were measured, respectively, and the front retardation at the wavelengths of 450 nm, 590 nm, and 630 nm of the unstretched film converted to a film thickness of 80 μm was Re ₄₅₀ , Re ₅₉₀ , Re ₆₃₀ , ΔRe = Re _The result is shown in Table 2 as _630- Re ₄₅₀ .

Films F-2, 3, 4, 5, 6, 8, 9, and 10 were stretched at temperatures and stretch ratios as shown in Table 2, and stretched films F-2 ′, 3 ′, 4 ′, 5 ′, and 6 ′. , 8 ′, 9 ′, 10 ′. The film thickness and the front retardation at wavelengths of 450 nm, 590 nm, and 630 nm were measured, and the front retardation of the unstretched film converted into a film thickness of 80 μm at wavelengths of 450 nm, 590 nm, and 630 nm was Re ₄₅₀ , Re ₅₉₀ , Re ₆₃₀ , ΔRe = Re ₆₃₀ -Re _450, and Table 2 shows the results.

(Comparative Examples 1-2)
A film was produced from the polymers PC-1 and PC-2 in the same manner as in Example 11 to obtain films FC-1 and FC-2. The film thickness and the front retardation at wavelengths of 450 nm, 590 nm, and 630 nm were measured, respectively, and the front retardation at the wavelengths of 450 nm, 590 nm, and 630 nm of the unstretched film converted to a film thickness of 80 μm was Re ₄₅₀ , Re ₅₉₀ , Re ₆₃₀ , ΔRe = Re _The result is shown in Table 2 as _630- Re ₄₅₀ .

Films FC-1 and 2 were subjected to stretching temperatures and stretch ratios as shown in Table 2 to obtain stretched films FC-1 ′, 1 ″ and 2 ′. The film thickness and the front retardation at wavelengths of 450 nm, 590 nm, and 630 nm were measured, and the front retardation of the unstretched film converted into a film thickness of 80 μm at wavelengths of 450 nm, 590 nm, and 630 nm was Re ₄₅₀ , Re ₅₉₀ , Re ₆₃₀ , ΔRe = Re ₆₃₀ -Re _450, and Table 2 shows the results.

  As in Comparative Examples 1 and 2, the wavelength dispersion characteristics of the retardation of the norbornene polymer film having a hydrogen absorption body of benzene having a short absorption wavelength can be changed between positive and negative by the endo / exo steric structure. The value is small. On the other hand, as in the present invention, the absolute value of the wavelength dispersion characteristic of the retardation of a norbornene polymer film having a hydrogen absorption body of naphthalene or pyrene having an absorption wavelength at a maximum absorption wavelength of 300 nm to 400 nm is more greatly expressed. I understand that

Example 21 Production of Polarizing Plate The produced film F-1 ′ and a cellulose acylate film (Fuji Photo Film, Fuji TAC) were immersed in an aqueous 1.5N sodium hydroxide solution at 60 ° C. for 2 minutes. Thereafter, it was immersed in a 0.1N aqueous sulfuric acid solution for 30 seconds, and then passed through a water-washing bath to obtain saponified F-1 ′ and Fuji TAC.

  According to Example 1 of JP 2001-141926 A, a peripheral speed difference is given between two pairs of nip rolls, and a 75 μm thick polyvinyl alcohol film (manufactured by Kuraray Co., Ltd., 9 × 75RS) is stretched in the longitudinal direction. A polarizing film was obtained.

  The polarizing film thus obtained and the saponified F-1 ′ were mixed with a 3% by mass aqueous solution of PVA (manufactured by Kuraray Co., Ltd., PVA-117H) as an adhesive so that the longitudinal direction of the film was 45 °. A polarizing plate Pol-1 was prepared by laminating with a layer structure of “saponified F-1 ′ / polarizing film / saponified FujiTAC”.

(Example 22: Production and evaluation of liquid crystal display device)
Among two pairs of polarizing plates installed with a liquid crystal layer sandwiched between 26-inch and 40-inch liquid crystal display devices (manufactured by Sharp Corporation) using VA type liquid crystal cells, a polarizing plate on one side on the viewer side is used. It peeled off and the said polarizing plate Pol-1 was affixed instead using the adhesive. A liquid crystal display device was prepared by arranging so that the transmission axis of the polarizing plate on the observer side and the transmission axis of the polarizing plate on the backlight side were orthogonal to each other. The obtained liquid crystal display device was observed for light leakage and color unevenness generated in the black display state, and in-plane uniformity. The liquid crystal display device incorporating the polarizing plate Pol-1 of the present invention was very excellent without any change in color tone.

Claims (9)

A substituent containing a hydrogen-leaved product of an aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 [mol ⁻¹ dm ³ cm ⁻¹ ]; A norbornene-based polymer, which is formed only of a repeating unit derived from a norbornene-based compound represented by the following general formula (I) and at least one repeating unit represented by the following general formula (II) .
(Wherein R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or 300 nm to 400 nm) A substituent containing a hydrogen- leaved product of an aromatic compound having a maximum absorption wavelength and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 [mol ⁻¹ dm ³ cm ⁻¹ ], and at least one Is a substituent containing the hydrogen-eliminating body.)
(Wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ are each a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or —L— O—CO—R ⁹ (L is a single bond or an alkylene group having 1 to 10 carbon atoms, and R ⁹ is an alkyl group having 1 to 5 carbon atoms), at least one of which is —L—O—. CO-R ⁹ ) Wherein of R ^1, R ^2, R ³ and R ^4, substituents other than the substituent containing hydrogen withdrawal member, respectively, norbornene polymer according to claim 1 is a hydrogen atom or an alkyl group. Wherein R ^1, one of R ^2, R ³ and R ^4, 1 or 2 but norbornene polymer according to claim 1, wherein the substituent containing hydrogen withdrawal member. The norbornene-based polymer according to any one of claims 1 to 3 , wherein a substituent containing the hydrogen-eliminating substance is substituted with an exo linkage. The aromatic compound having a maximum absorption wavelength at 300 nm to 400 nm and a molar extinction coefficient at the maximum absorption wavelength of 10 to 100,000 [mol ⁻¹ dm ³ cm ⁻¹ ] is a 2 to 4 cyclic aromatic compound. The norbornene-based polymer according to any one of claims 1 to 4 . The norbornene-based polymer according to any one of claims 1 to 5 , comprising 3 to 50% of a repeating unit represented by the general formula (I) in a polymerization composition ratio. A film comprising the norbornene-based polymer according to any one of claims 1 to 6 . A polarizing plate comprising a polarizing film and the film according to claim 7 . A liquid crystal display device comprising the polarizing plate according to claim 8 .