JP2010077323A - Norbornene-based addition polymer, optical material using it, polarizing plate, and image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a norbornene-based addition polymer applicable to a cooling flow casting film forming process. <P>SOLUTION: The norbornene-based addition polymer includes at least one of a repeating unit represented by general formula (1A), and at least one of a repeating unit represented by general formula (1B), (in the general formula (1A) and in the general formula (1B) R<SP>1</SP>-R<SP>4</SP>each independently represent a hydrogen atom or a substituent, L<SP>1</SP>, L<SP>2</SP>each independently represent a single bond or a divalent linking group, m, p each independently are an integer of 0 or 1, n, q are each independently an integer of 1-4, r, s each independently are an integer of 1-3, in the case r, s are 2 or more, R<SP>1</SP>, R<SP>3</SP>may be same or different, A represents COOR<SP>5</SP>or OCOR<SP>5</SP>, and R<SP>5</SP>represents a substituent). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a norbornene-based addition polymer applicable to a cooling casting film forming method, an optical material using the same, a polarizing plate, and an image display device.

In recent years, cellulose acylate films and norbornene polymer films are mainly used as films for liquid crystal display devices. The cost of these films depends not only on the cost of the material itself, but also on the productivity of the film manufacturing (film forming) method.
As a method for forming a cellulose acylate film, a cooling casting film forming method is generally used (Patent Document 1). In this method, a high-concentration cellulose acylate solution is cast, and the film is allowed to cool immediately without being dried so that the film has self-supporting property, and is peeled off from the die and dried. In this method, since the double-sided drying is performed from the initial stage of drying, the film is very quickly dried. Therefore, high-speed film formation of hundreds of tens of meters per minute is possible. In other words, it is excellent in film productivity.
On the other hand, as a typical method for forming a norbornene-based polymer, particularly a cyclic olefin-based polymer composed only of hydrocarbons, there is a melt film-forming method (Patent Document 2). This method has a film forming speed as low as about several tens of meters per minute and is extremely inferior in productivity as compared with the above high-speed film forming. In the cyclic olefin polymer containing a polar group, a solution film-forming method is also seen, but there is no description regarding a film-forming method capable of high-speed film formation as described above (Patent Documents 3 and 4).
In addition, use of a cyclic olefin copolymer containing a plurality of types of repeating units as an optical material has been proposed (Patent Document 5). However, Patent Document 5 does not show a description of the structure of the norbornene-based addition polymer of the present invention described below and the effect of improving the cooling gelation ability based on the structure.

JP 2004-98512 A Japanese Patent No. 3846567 JP 2001-354755 A International Publication No. 04/049011 Pamphlet JP 2002-20435 A

An application condition of the cooling casting film forming method is that gelation (solidification) occurs when the polymer solution (dope) is cooled. Since this cooling gelation ability is a property found only in a specific polymer, there are not so many examples of application to the cooling casting film forming method. In particular, there are no applications to cyclic olefin polymers. The general cyclic olefin-based polymers found in Patent Documents 3 and 4 do not have a cooling gelation ability, and therefore high-speed film formation is difficult.
An object of the present invention is to provide a cyclic olefin-based polymer, particularly a norbornene-based addition polymer, an optical material using the same, a polarizing plate, and an image display device applicable to a cooling casting film forming method.

  In order to solve the above-described problems, the present inventor has worked to develop a cooling gelation ability in a norbornene-based addition polymer. First, attention was paid to norbornene-based addition polymers into which hydrogen bonds were introduced so as to form a network between the polymers. Among them, it has been found that by introducing an acyloxy group (a group in which an oxygen atom is linked to an acyl group) or an ester group and an amide group into the polymer, the norbornene-based addition polymer can also exhibit cooling gelation ability. That is, the above problem has been solved by the following means.

1. A norbornene-based addition polymer containing at least one repeating unit represented by the following general formula (1A) and at least one repeating unit represented by the following general formula (1B).

(In General Formula (1A) and General Formula (1B), R ^{1 to} R ⁴ each independently represents a hydrogen atom or a substituent. L ¹ and L ² each independently represents a single bond or a divalent linking group. M and p are each independently an integer of 0 or 1, n and q are each independently an integer of 1 to 4, r and s are each independently an integer of 1 to 3, where r and s are 2 In these cases, R ¹ and R ³ may be the same or different from each other, A represents COOR ⁵ or OCOR ⁵ , and R ⁵ represents a substituent.)
2. The ratio of the total mole number x of the repeating unit represented by the general formula (1A) to the total mole number y of the repeating unit represented by the general formula (1B) is 0.03 ≦ y / (x + y) ≦. 2. The norbornene-based addition polymer according to 1 above, which is 0.50.
3. The norbornene-based addition polymer as described in 1 or 2 above, wherein m and p are 0 and n and q are 1.
4. Any of the above 1 to 3, wherein L ¹ and L ² are a single bond, R ¹ and R ³ are a hydrogen atom, A is COOR ⁵ and R ⁵ is an alkyl group having 1 to 4 carbon atoms. The norbornene-based addition polymer described in 1.
5. An optical material containing the norbornene-based addition polymer as described in any one of 1 to 4 above.
6. The optical material as described in 5 above, wherein the optical material is in the form of a thin film, film or sheet.
7. The optical material as described in 5 or 6 above, wherein Re and Rth are in the following ranges.
(1) 0 ≦ Re ≦ 100 nm
(2) 0 ≦ Rth ≦ 400 nm
(In the formula, Re and Rth represent in-plane retardation (Re) and retardation in the thickness direction (Rth) at a wavelength of 590 nm.)
8. A polarizing plate having a polarizing film and protective films provided on both sides of the polarizing film, wherein at least one of the protective films is the optical material according to any one of 5 to 7 above. .
9. An image display device comprising the optical material according to any one of 5 to 7 or the polarizing plate according to 8 above.

  The norbornene-based addition polymer of the present invention can exhibit cooling gelation ability by introducing an acyloxy group or an ester group and an amide group into the side chain, and can be applied to a cooling casting film forming method. Very good. Moreover, the polarizing plate using the optical material comprising the norbornene-based addition polymer of the present invention as a protective film has excellent adhesion to the polarizing film and good adhesion during processing. Furthermore, an image display device using the polarizing plate can provide an excellent image.

Hereinafter, the present invention will be described in more detail.
[Polymer structure]
The norbornene-based addition polymer of the present invention (hereinafter also referred to as the polymer of the present invention) is represented by at least one repeating unit represented by the following general formula (1A) and at least one following general formula (1B). And a norbornene-based addition polymer.

In General Formula (1A) and General Formula (1B), R ^{1 to} R ⁴ each independently represent a hydrogen atom or a substituent. L ¹ and L ² each independently represents a single bond or a divalent linking group. m and p are each independently an integer of 0 or 1, n and q are each independently an integer of 1 to 4, and r and s are each independently an integer of 1 to 3. In addition, when r and s are 2 or more, R ¹ and R ³ may be the same or different. A represents COOR ⁵ or OCOR ⁵ , and R ⁵ represents a substituent.

  In the norbornene-based addition polymer, a plurality of repeating units represented by the general formula (1A) and / or the general formula (1B) may exist.

  When the polymer of the present invention is dissolved in an appropriate solvent, it has an acyloxy group or an ester group and an amide group, so that the polymers can form a hydrogen bond to form a gel. On the other hand, if the other side chain A of the polymer is not an acyloxy group or an ester group, the dope is not transparent and a transparent film cannot be obtained.

The ratio of the total mole number x of the repeating unit represented by the general formula (1A) to the total mole number y of the repeating unit represented by the general formula (1B) is 0.03 ≦ y / (x + y) ≦ 0.50. It is preferable to satisfy the following relational expression. When y / (x + y) <0.03, that is, when the amount of the amide group is small, the cooling gelation ability (stripping property) tends to be low. On the other hand, when y / (x + y)> 0.50, that is, when the amount of the amide group is large, there is a tendency that the solvent is not completely dissolved in the solvent. In order to satisfy both properties, it is preferable to satisfy 0.03 ≦ y / (x + y) ≦ 0.50. More preferably 0.05 ≦ y / (x + y) ≦ 0.50, still more preferably 0.05 ≦ y / (x + y) ≦ 0.40, and most preferably 0.10 ≦ y / (x + y). ≦ 0.40.
In order to set x and y in this range, it is possible to adjust the degree appropriately by a known method.

The ratio of y / (x + y), that is, the amide group can be measured by a spectroscopic technique such as NMR or IR. For example, the ¹³ C-NMR of the polymer is measured, and the ratio of the amide group can be determined from the integrated value of the carbonyl carbon of the acyloxy group or ester group and the amide group.

  The repeating unit represented by the following general formula (1A) will be further described.

In General Formula (1A), R ¹ represents a hydrogen atom or a substituent. L ¹ represents a single bond or a divalent linking group. m represents an integer of 0 or 1, n represents an integer of 1 to 4, and r represents an integer of 1 to 3. In addition, when r is 2 or more, R ¹ may be the same or different. A represents COOR ⁵ or OCOR ⁵ , and R ⁵ represents a substituent. In the norbornene-based addition polymer, a plurality of repeating units represented by the general formula (1A) may be present.

R ¹ represents a hydrogen atom or a substituent. Examples of the substituent include a halogen (for example, a chlorine atom, a bromine atom, an iodine atom), an alkyl group [a linear, branched, cyclic substituted or unsubstituted alkyl group. To express. They are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl). A cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably having 5 to 30 carbon atoms). A substituted or unsubstituted bicycloalkyl group, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl), a tricyclo structure with more ring structures Domo is intended to cover. An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below also represents such an alkyl group. ], An alkenyl group [represents a linear, branched or cyclic substituted or unsubstituted alkenyl group. They are alkenyl groups (preferably substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, such as vinyl, allyl, prenyl, geranyl, oleyl), cycloalkenyl groups (preferably substituted or substituted groups having 3 to 30 carbon atoms). An unsubstituted cycloalkenyl group, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms (for example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), Bicycloalkenyl group (a substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a bicycloalkene having one double bond. For example, bicyclo [2,2,1] hept-2-en-1-yl, bicyclo 2,2,2] oct-2-en-4-yl). An alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl, propargyl, trimethylsilylethynyl group), an aryl group (preferably a substituted or unsubstituted aryl having 6 to 30 carbon atoms) Groups such as phenyl, p-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl), heterocyclic groups (preferably 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocycles A monovalent group obtained by removing one hydrogen atom from a compound, more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms, such as 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy (Preferably, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy), aryloxy group (preferably carbon A substituted or unsubstituted aryloxy group of formula 6 to 30, for example, phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylaminophenoxy), silyloxy group (preferably, A silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy, t-butyldimethylsilyloxy), an acyloxy group (preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, 6 carbon atoms To 30 substituted or unsubstituted ants Rucarbonyloxy group such as formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy), alkoxycarbonyloxy group (preferably substituted or unsubstituted alkoxycarbonyloxy having 2 to 30 carbon atoms) A group such as methoxycarbonyloxy, ethoxycarbonyloxy, t-butoxycarbonyloxy, n-octylcarbonyloxy), an aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, For example, phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, pn-hexadecyloxyphenoxycarbonyloxy), amino group (preferably amino group A substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as amino, methylamino, dimethylamino, anilino, N-methyl-anilino, diphenylamino ), A mercapto group, an alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, such as methylthio, ethylthio, n-hexadecylthio), an arylthio group (preferably a substituted or unsubstituted group having 6 to 30 carbon atoms) Arylthio such as phenylthio, p-chlorophenylthio, m-methoxyphenylthio), a heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms such as 2-benzothiazolylthio 1-phenyltetrazol-5-ylthio), sulfo Amoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms such as N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N- Acetylsulfamoyl, N-benzoylsulfamoyl, N- (N′-phenylcarbamoyl) sulfamoyl), sulfo group, alkyl and arylsulfinyl group (preferably substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms) 6 to 30 substituted or unsubstituted arylsulfinyl groups such as methylsulfinyl, ethylsulfinyl, phenylsulfinyl, p-methylphenylsulfinyl), alkyl and arylsulfonyl groups (preferably substituted or unsubstituted groups having 1 to 30 carbon atoms) Substitution al Rusulfonyl group, 6-30 substituted or unsubstituted arylsulfonyl group, for example, methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p-methylphenylsulfonyl), acyl group (preferably formyl group, C2-30 substitution) Or an unsubstituted alkylcarbonyl group, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, a heterocyclic carbonyl group bonded to the carbonyl group at a substituted or unsubstituted carbon atom having 4 to 30 carbon atoms, for example, , Acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl), an aryloxycarbonyl group (preferably a C7-30 substituent or Unsubstituted aryl Sicarbonyl group such as phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, pt-butylphenoxycarbonyl), alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms) , For example, methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl), silyl group (preferably a substituted or unsubstituted silyl group having 3 to 30 carbon atoms, such as trimethylsilyl, t-butyldimethylsilyl Among them, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms is more preferable, a hydrogen atom or a methyl group is more preferable, and a hydrogen atom is most preferable.

A is OCOR ⁵ or COOR ⁵ , and is preferably COOR ⁵ because it easily forms a hydrogen bond between the polymers and improves the gelation ability.

R ⁵ is a substituent, and examples thereof are the same as those of R ¹ described above. Among them, an alkyl group is preferable, a linear alkyl group having 1 to 4 carbon atoms is more preferable, a methyl group, an ethyl group, Or a butyl group is the most preferable.

L ¹ is a single bond or a divalent linking group (preferably an alkylene, alkenylene, alkynylene, arylene which may be substituted, or a group obtained by combining two or more of these divalent groups. And may be further linked by another divalent linking group), preferably a single bond or an alkylene group, more preferably a single bond or an alkylene having 1 to 3 carbon atoms. A group, more preferably a single bond or methylene, and most preferably a single bond.

  m represents 0 or 1, and is preferably 0 for the convenience of production. n represents an integer of 1 to 4, but is preferably 1 to 2 and more preferably 1 for the convenience of production.

  Although the specific example of general formula (1A) in this invention is shown below, it is not limited to this.

  The repeating unit represented by the following general formula (1B) will be described.

In general formula (1B), R ² and R ⁴ each independently represent a hydrogen atom or a substituent. L ² represents a single bond or a divalent linking group. p represents an integer of 0 or 1, q represents an integer of 1 to 4, and s represents an integer of 1 to 3. When s is 2 or more, R ³ may be the same or different. In the norbornene-based addition polymer, a plurality of repeating units represented by the general formula (1B) may exist.

R ³ represents a hydrogen atom or a substituent, and examples of the substituent include those similar to R ¹ described above. Among these, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms is more preferable, and a hydrogen atom or methyl Groups are more preferred and hydrogen atoms are most preferred.

R ^{2 to} R ⁴ each independently represent a hydrogen atom or a substituent, and examples of the substituent include the same examples as the substituent of R ¹ described above. Among these, a hydrogen atom, an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, or an unsubstituted or substituted aryl group having 6 to 10 carbon atoms is preferable, and a hydrogen atom or an unsubstituted group is more preferable. Examples thereof include a substituted or substituted alkyl group having 1 to 10 carbon atoms.

L ² is the same as L ¹ described above, preferably a single bond or an alkylene group, more preferably a single bond or an alkylene group having 1 to 3 carbon atoms, and still more preferably a single bond.

  p represents an integer of 0 or 1, and is preferably 0 for the same reason as m. q represents an integer of 1 to 4, and is preferably 1 to 2 and more preferably 1 for the same reason as n.

A norbornene-based addition polymer in which m and p are 0 and n and q are 1 is particularly preferable.
A norbornene addition polymer in which L ¹ and L ² are single bonds, R ¹ and R ³ are hydrogen atoms, A is COOR ⁵ and R ⁵ is an alkyl group having 1 to 4 carbon atoms is also particularly preferable. .

Specific examples represented by the general formula (1B) are shown below, but the present invention is not limited thereto.

  The norbornene-based addition polymer of the present invention may comprise only the repeating units represented by the general formula (1A) and the general formula (1B), but contains the repeating unit represented by the general formula (1C). You can also. When the repeating unit represented by the following general formula (1C) is included, the proportion of 1 to 50 mol% in the polymer is desirable.

R ⁶ , R ⁷ , R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a carbon number. It represents either 1 to 10 acyl groups or carboxyl groups. Further, if possible, at least two of R ⁶ , R ⁷ , R ⁸ and R ⁹ may be connected to each other to form a 5- to 7-membered ring, but it should be a 5- or 6-membered ring. More preferred. Further, it may be a carbocyclic ring or a heterocyclic ring. t represents an integer of 0 or 1, and more preferably 0.

  Specific examples represented by the general formula (1C) are shown below, but the present invention is not limited thereto.

  By introducing the repeating unit represented by the general formula (1C) at an arbitrary ratio, the physical properties (moisture permeability, wavelength dispersion, elastic modulus) of the film can be controlled.

  Although the specific example of the polymer of this invention containing the repeating unit represented by General formula (1A) and General formula (1B) is shown below, this invention is not limited to these. The numerical value on the right of () in the following polymer indicates the mol% ratio of the copolymerization ratio.

  When the norbornene-based addition polymer of the present invention contains an ethylenic olefin as a repeating unit in the main chain, not only the glass transition point is lowered but also the Rth in the case of a film is reduced. High Rth film cannot be obtained. Therefore, the norbornene-based addition polymer of the present invention does not contain an ethylenic olefin as a repeating unit.

  The polymer of the present invention can be synthesized with reference to methods known in the literature. For example, Bull. Chem. Soc. Jpn. 48, 3641-3644 (1975), and J. Org. Chem. Soc. Perkin Trans. 2, 17-22 (1974), etc., but the method for synthesizing the polymer of the present invention is not limited to these methods.

The polymer of the present invention can also be obtained by the following method.
[Pd (CH ₃ CN) ₄ ] [BF ₄ ] ₂ , di-μ-chloro-bis- (6-methoxybicyclo [2.2.1] hept-2-ene-endo-5σ, 2π) -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 -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 MAO, etc., Group 8 Ni, Pd. Using a cation complex such as Co or a catalyst that forms a cation complex, cycloaliphatic hydrocarbon solvents such as cyclohexane, cyclopentane, and methylcyclopentane, aliphatic hydrocarbon solvents such as pentane, hexane, heptane, and octane, toluene, Selected from aromatic hydrocarbon solvents such as benzene and xylene, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethylene and chlorobenzene, polar solvents such as ethyl acetate, butyl acetate, γ-butyrolactone, propylene glycol dimethyl ether and nitromethane. It can be obtained by (co) polymerizing a specific cyclic olefin compound in the range of −20 to 100 ° C. in a solvent.
Further, the method described in Macromolecules, 1996, 29, 2755, Macromolecules, 2002, 35, 8969, International Publication No. 2004/7564 is also suitable. Used for.
The norbornene-based addition polymer of the present invention preferably has a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatogram using tetrahydrofuran as a solvent, preferably 100,000 to 700,000, more preferably 100,000. It is -500,000, More preferably, it is 100,000-400,000. When the weight average molecular weight in terms of polystyrene is less than 100,000, the peelability at the time of film production is insufficient and the breaking strength may be insufficient, and the weight average molecular weight in terms of polystyrene exceeds 700,000. When the sheet is made into a cast film or the like, the solution viscosity becomes high and the handling becomes difficult.
The preferred glass transition temperature of the norbornene-based addition polymer of the present invention is 100 to 400 ° C., preferably 150 to 380 ° C., more preferably 200 to 350 ° C., as measured by a scanning differential calorimeter (DSC). When the temperature is less than 0 ° C., thermal deformation tends to occur when used as an optical material. Moreover, when it exceeds 400 degreeC, when performing the shaping | molding process by a heat | fever, a polymer may thermally decompose.
The preferred tensile modulus of the norbornene-based addition polymer of the present invention is preferably 1200 MPa or more, more preferably 1500 MPa or more. When the tensile elastic modulus is low, the film does not have sufficient self-supporting property, and it may be difficult to handle it as an optical material such as a polarizing plate.

  The norbornene-based addition polymer of the present invention comprises a crosslinking agent such as a silane coupling agent containing a peroxide, sulfur, disulfide, polysulfide compound, dioxime compound, tetrasulfide and the like with respect to 100 parts by mass of the polymer of the present invention. 0.05-5 mass parts can be added and it can also convert into a crosslinked body with a heat | fever etc., and can also be directly converted into a crosslinked body with light and an electron beam.

[Physical properties of polymer]
(Determination of cooling gelation ability)
The norbornene-based addition polymer of the present invention has a cooling gelling ability. In order to discriminate a polymer having cooling gelation ability, viscoelasticity can be measured with a rheometer or the like. This is because the polymer dope is cooled and has a temperature at which a sudden increase in viscosity is observed at a certain temperature. However, since the object of the present invention is to discriminate a polymer capable of high-speed film formation, it is preferable to actually examine and determine cooling casting film formation. You can easily test on a small scale. The polymer dope can be cast on a small scale with a cooled metal plate, and the peelability can be confirmed. For example, a polymer is dissolved in a mixed solvent such as methylene chloride / methanol / butanol / water, and the obtained dope is cast on a SUS plate set at 0 ° C. to −40 ° C. using an applicator to form a cast film. Do. If this film is peeled off and there is no residue on the SUS plate, it can be determined that high-speed film formation is possible.

[Polymer film]
The optical material of the present invention is characterized by using the norbornene-based addition polymer of the present invention, and the optical material is preferably in the form of a thin film, a film or a sheet. Hereinafter, a film will be described as an example (hereinafter sometimes referred to as a film of the present invention).
The film of the present invention refers to a film containing the norbornene-based addition polymer of the present invention. Films produced using the polymer are optical applications including substrates for liquid crystal display elements, light guide plates, polarizing films, retardation films, liquid crystal backlights, liquid crystal panels, OHP films, transparent conductive films, etc. Suitable for film.

[Method for producing polymer film]
The film of the present invention contains the norbornene-based addition polymer of the present invention, and can be produced by forming a film using the polymer as a raw material. For film formation, it is preferable to use a solution film forming method capable of obtaining a film having an excellent surface shape. As 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 conventionally used for producing cellulose triacetate films are 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 applied in the present invention. The solution casting method is described below.

(solvent)
Any known solvent can be used as the solvent for preparing the dope used in the solution casting film-forming method of the present invention. In particular, halogenated hydrocarbons such as methylene chloride (dichloromethane), esters such as methyl acetate, ethers, alcohols (eg, methanol, ethanol, n-butanol, etc.), ketones (eg, acetone, etc.), etc. Is preferably used, but is not limited thereto. It is also possible to prepare a dope from a solvent in which a plurality of these solvents are mixed and form a film from the dope. In particular, in the present invention, it is preferable to use a mixed solvent containing methylene chloride as a main solvent, for example, methylene chloride / methanol / butanol / water.

(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 according to the application, for example, plasticizers, deterioration inhibitors, UV inhibitors, retardation (optical anisotropy) regulators, fine particles, peeling accelerators, infrared absorbers, etc. ) And the like. 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. 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-t-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-t-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 a polarizing plate or 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 a small 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 ultraviolet absorbers 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 compounds Etc. The added 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 of the present invention.

  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 (polarizing film) and the film during processing of the polarizing plate. If the matting agent used in the present invention is an inorganic fine particle, it is a fine particle having an average particle diameter of 0.05 μm to 0.5 μm, preferably 0.08 μm to 0.3 μm, more preferably 0.1 μm to 0.25 μm. It is. The fine particles are preferably silicon dioxide, silicone and titanium dioxide as the inorganic compound, and the polymer compound is preferably fluororesin, nylon, polypropylene and chlorinated polyether, more preferably silicon dioxide, and particularly preferably organic matter. It is silicon dioxide that is surface treated.

  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 most preferably 0.1 to 0.5% by mass with respect to the polymer of the present invention.

(Preparation of dope)
The above-described solid content (polymer and additive) is charged into the above-described methylene chloride solvent, and then dissolved by any known dissolution method to prepare a dope. This dope generally removes foreign matters by filtration. Various known filter media such as filter paper, filter cloth, non-woven fabric, metal mesh, sintered metal, and perforated plate can be used for filtration. By filtering, foreign substances and undissolved substances in the dope can be removed, and defects due to foreign substances in the product film can be reduced.

  Moreover, the dope once prepared can be heated to further improve the solubility. For heating, there are a method of heating while stirring in a stationary tank, a method of heating while transferring the dope using various heat exchangers such as a multi-tube type, a jacket pipe with a static mixer, and the like. Moreover, a cooling process can also be implemented after a heating process. It is also possible to heat the apparatus to a temperature higher than the boiling point of the dope by pressurizing the inside of the apparatus. By performing these treatments, fine undissolved substances can be completely dissolved, and foreign matters on the film can be reduced and filtration load can be reduced.

  In the present invention, the mass percentage (dope solid content concentration) of the dope is preferably 15% by mass to 30% by mass, and more preferably 20% by mass to 25% by mass. If it is less than 15% by mass, the solid content concentration of the dope is too low, so that the gel film formed from the dope may require a long time until it has a preferable film stress, which may increase the cost. On the other hand, if the solid concentration is too low, a gel film may not be formed when the dope is cast. On the other hand, if it exceeds 30% by mass, the viscosity of the dope becomes too high and the bead leveling effect (smoothing) becomes difficult to be exhibited, and it may be difficult to form a uniform film.

(Solution casting film forming method)
There are many literatures on solution casting film forming methods. In the recent solution casting film forming method, the time required from the casting of the dope onto the support to the peeling of the molded film on the support is shortened, and the productivity of the film-controlling worker is improved. Is a problem. For example, Japanese Patent Publication No. 5-17844 proposes to shorten the time until stripping after casting by casting a high-concentration dope on a cooling drum. In film formation in the present invention, it is preferable to use this drum film formation method. The drum film forming method will be described below.

  FIG. 1 shows a schematic view of a film production line 10 used for carrying out the solution casting film production method according to the present invention. Moreover, the principal part schematic of the film forming line 10 was shown to FIG.2 and FIG.3. In the mixing tank 11, the dope 12 prepared by the above-described method is charged and stirred by the stirring blade 13 to be uniform. The dope 12 is sent to the filtration device 15 by the pump 14 to remove impurities. Then, it is sent to a casting die 21 installed in the casting chamber 20 at a constant flow rate. The casting die 21 is disposed on the rotating drum 22. The rotary drum 22 is rotationally driven by a driving device (not shown). A casting bead 23 is formed by casting the dope 12 from the casting die 21 on the rotating drum 22. In the present invention, the position at which the casting bead 23 has landed on the rotating drum 22 is indicated by a landing line (see FIG. 2, since the figure is shown from a direction perpendicular to the film traveling direction). ) 22a. The casting bead 23 is gelled on the rotating drum 22 as a support to become a gel film 24. When the gel film 24 moves as the rotary drum 22 travels, gelation further proceeds due to cooling. When the gel film 24 reaches the peeling line (see FIG. 2) 22b, it is peeled off from the rotating drum 22 by the peeling roller 25 to become a film 26. In addition, it is more preferable that the dry air 19 is blown from a blower (not shown) in the direction opposite to the rotation direction of the rotary drum 22.

  As shown in FIG. 3, the rotating drum 22 is provided with support rotating shafts (hereinafter referred to as rotating shafts) 40 and 41, and bearings 42 and 43 are attached to the rotating shafts 40 and 41, respectively. It is installed in the main body of the casting apparatus that does not rotate. The rotation shaft 40, the rotation drum 22, and the rotation shaft 41 are provided with a medium flow path (not shown) therein. A cooling medium (hereinafter referred to as a refrigerant) 44 that is an antifreeze heat medium is supplied from the refrigerant supply device 45 to the flow path, whereby the rotary drum 22 is cooled. In the present invention, the surface temperature of the rotating drum 22 is preferably 10 ° C. or lower, more preferably −5 ° C. or lower, most preferably −20 ° C. or lower. However, the present invention is not limited to those temperature ranges.

  As the refrigerant 44, a glycol-based refrigerant, a fluorine-based refrigerant, an alcohol-based refrigerant, or the like is used, and most preferably, Fluorinert (registered trademark) FC-77, HFE7100, cold brine (registered trademark) FP60 is used. It is not limited to the refrigerant. Further, the cooling method of the rotating drum used in the present invention is not necessarily limited to the method of passing the coolant as shown in FIG.

  Furthermore, it is more preferable that the rotating drum 22 used in the present invention is made of a low-temperature brittle material because the physical strength against the impact of the equipment and the repeated load can be prevented when cooled at a low temperature. Specifically, those produced using SUS material, SLA material, STPL material, etc. are preferable, but not limited thereto.

  As shown in FIG. 2, it is preferable that a gas pipe 27a connected to a gas supply device 27 is attached to the casting die 21 on the bead back surface 23b side. By blowing gas (hereinafter also referred to as a first gas) 28 through the gas pipe line 27a to the bead back surface 23b, the gas concentration on the bead back surface 23b can be reduced, and the dew point can be lowered. Thereby, dew condensation on the surface of the rotating drum 22 can be prevented, and deterioration of the surface quality of the film 26 is suppressed. Furthermore, when condensation occurs on the surface of the rotating drum 22 where condensation has occurred, the gel film 24 falls off from the rotating drum 22 between the landing line 22a and the stripping line 22b when the gel film 24 is formed, which hinders continuous operation. . According to the present invention, the condensation on the surface of the rotary drum 22 can be prevented, so that the gel film 24 can be prevented from falling off. The gas 28 is preferably nitrogen gas, helium gas or the like (usually called an inert gas) that does not affect the characteristics of the film.

  Further, it is preferable that the gas 28 is blown after the temperature of the gas 28 is adjusted by the gas supply device 27 so that the dew point is 1 ° C. or more lower than the surface temperature of the rotating drum 22. Note that any known device may be used to measure the temperature of the surface of the rotary drum 22 (illustration of a thermometer is omitted). If this temperature difference is less than 1 ° C., condensation occurs due to slight variations in process conditions. Furthermore, it is preferable that the wind speed of the gas 28 be in the range of 0.5 m / s to 2 m / s. When the wind speed is less than 0.5 m / s, the effect of reducing the gas concentration in the vicinity of the casting bead 23 is small. If the wind speed is higher than 2 m / s, wind unevenness may occur in the casting bead 23, and the surface quality of the film may be deteriorated. Moreover, it is preferable that the temperature of the 1st gas 28 is the range of 30 to 50 degreeC. However, in the present invention, the wind speed and temperature of the gas (first gas) are not limited to the above ranges by changing other experimental conditions.

  The dope 12 cast on the surface of the rotating drum 22 increases the strength (film strength) of the gel film 24 due to cooling gelation, and further promotes drying until stripping, whereby the strength of the gel film 24 is also increased. (Film strength) increases. When the stress (film stress) due to stretching of the gel film 24 at the time of stripping is less than 450,000 Pa, the strength as a film is insufficient, and the self-supporting property necessary for stripping may not be obtained. In the present invention, the stress value due to stretching is preferably 450,000 Pa or more, more preferably 600,000 Pa or more, and most preferably 750,000 Pa or more. In the present invention, as the stress value due to stretching of the film, a value measured by stretching using a load cell is used.

  When the gel film 24 is peeled off as the film 26, the speed ratio V1 / V0 between the peripheral speed (V0) of the rotating drum 22 and the peripheral speed (V1) of the stripping roller 25 is 1.001 ≦ (V1 / V0). ≦ 1.5, preferably 1.002 ≦ (V1 / V0) ≦ 1.3, and most preferably 1.005 ≦ (V1 / V0) ≦ 1.2. It is to make a range. By setting the ratio of (V1 / V0) to the range described above, the stretching force applied to the film 26 is increased, and the stripping becomes stable. When the speed ratio is less than 1.001, the stretching force of the film is insufficient, the peel line 22b rises, and it becomes difficult to peel the film uniformly. On the other hand, if the speed ratio is greater than 1.5, a film (soft film) immediately after stripping with a high volatile content may cause problems such as “tearing” and “trickling” from the end of the ear due to rapid stretching. In the present invention, the speed ratio (V1 / V0) is not limited to the above-described range.

  When the clearance C1 between the rotating drum 22 and the peeling roller 25 is narrowed, the stretching speed increases, so that the stretching force increases and the stripping is stabilized. However, if the clearance C1 is less than 1 mm, the film may be cut by foreign matter such as film residue being caught. On the other hand, if the clearance C1 is larger than 100 mm, the effect of increasing the stretching force of the film is reduced, the stripping position is raised, and stripping may become unstable. Therefore, in the present invention, the clearance C1 is preferably in the range of 1 mm ≦ C1 ≦ 100 mm, but is not limited to this range. In the present invention, the clearance C1 means an interval between intersection points where the lines a connecting the centers of the rotary drum 22 and the stripping roller 25 intersect with the outer periphery when the rotary drum 22 and the peeling roller 25 are arranged on the same plane. Further, the peeling roller 25 has an angle D between the reference line of the rotating drum 22 (the reference line means a line vertically upward from the center of the rotating drum as shown) and the center line a 45. It is preferably disposed at a position of from 60 ° to 120 °, more preferably from 60 ° to 180 °.

In order to easily peel off the gel film 24 from the rotating drum 22, the difference between the surface tension of the rotating drum 22 and the surface tension of the dope 12 is 3 × 10 ⁻² (N / m) or more. 22 becomes difficult to get wet with a solvent, and the contact area of the gel film 24 and the rotating drum 22 decreases. Thereby, since peeling resistance at the time of peeling can be reduced, peeling is stabilized. In the present invention, any known method can be used for measuring the surface tension. In the present invention, the difference in surface tension is not limited to that described above.

  The gel film 24 does not exist on the rotating drum 22 between the stripping line 22b and the bead landing line 22a shown in FIG. In the present invention, this surface is referred to as a gel-free film surface 22c. As described above, the rotating drum 22 is cooled by supplying the refrigerant therein. Therefore, when the surface temperature of the gel-free film surface 22c reaches the dew point, condensation may occur on this surface. Further, since the rotating drum 22 travels endlessly, if the dope 12 is cast on the surface to which water droplets or condensed solvent adheres, the surface of the film to be formed may be deteriorated. Therefore, a gas (hereinafter also referred to as a second gas) 30 is blown onto the gel-free film surface 22c using a blower 29, and the temperature of the gel-free film surface 22c is set to 1 ° C. or more higher than the dew point near the casting bead 23. Can prevent water droplets and liquefied solvents from adhering. The temperature of the gas (second gas) 30 is preferably 50 ° C. to 100 ° C. and the wind speed is preferably in the range of 2 m / s to 10 m / s, but the present invention is not limited to these ranges. .

  As shown in FIG. 3, the refrigerant 44 is also passed through the rotary shafts 40 and 41. Therefore, when the atmosphere in the vicinity of the rotary shafts 40 and 41 and the bearings 42 and 43 is cooled and reaches the dew point, water vapor contained in the atmosphere is condensed and water droplets are generated. The casting chamber 20 also contains a vaporized solvent volatilized from the dope 12, and the vaporized solvent may be liquefied and adhere to the rotating shafts 40 and 41 and the bearings 42 and 43. When adhesion becomes intense, rotation failure will arise and there is a possibility that it may interfere with continuous film formation. Therefore, in the present invention, the fans 46 and 47 are provided in the vicinity of the rotary shafts 40 and 41 and the bearings 42 and 43 so that the gases (hereinafter also referred to as third gases) 48 and 49 are respectively supplied to the rotary shafts 40 and 41 and the bearings 42 and 43. It is possible to prevent dew condensation from occurring on the rotating shafts 40 and 41 and the bearings 42 and 43. The gas 48, 49 to be blown is not particularly limited as long as the temperature in the vicinity of the rotary shafts 40, 41 is not lower than the dew point, but specifically, a range of 20 ° C to 30 ° C is preferable. Moreover, although it is preferable that a wind speed is the range of 2 m / s-10 m / s, it is not limited to this range. In the present invention, the embodiment of the blower is not limited to that shown in FIG. For example, in FIG. 3, the blowers 46 and 47 are installed on the rotary shafts 40 and 41, respectively, but gas may be blown to both the rotary shafts 40 and 41 using a single blower.

  When performing the solution casting film forming method according to the present invention, if the casting die 21 and the rotating drum 22 are provided in the casting chamber 20, it is possible to prevent the casting bead 23 from being randomly blown. This is preferable because a film 26 having a uniform surface shape can be obtained. However, if dew condensation occurs in the casting chamber, water droplets or the like may adhere to the surface of the gel film 24 and defects such as streaks may occur on the surface of the film. When the liquid adheres to the rotating shafts 40 and 41 and the bearings 42 and 43 (see FIG. 3) and condenses, it may be difficult to control the rotational speed of the rotating drum 24. There are even cases where it doesn't move at all. Therefore, it is preferable that the casting chamber 20 includes a recovery device 31 that condenses and recovers the vaporized solvent.

  The recovery device 31 includes a condensing surface 31 a that condenses water vapor contained in the atmosphere in the casting chamber 20 and the vaporized solvent evaporated from the solvent in the gel film 24. The temperature of the condensing surface 31a is defined by the type of solvent constituting the dope 12 and is not particularly limited. However, in the present invention, it is preferably 1 ° C. or more lower than the surface temperature of the film 26, more preferably 1 ° C. to 20 ° C. lower than the surface temperature of the film 26. When the temperature difference is less than 1 ° C., the conditions of the casting process slightly fluctuate, so that liquid such as water droplets may adhere to the surface of the film 26. Further, if it is lower than 20 ° C., it is disadvantageous in terms of cost. In the present invention, the film surface temperature is preferably measured using a non-contact thermometer 32 in the vicinity of the measurement point 26a shown in FIG. 2, but the temperature measurement method is not limited thereto. Absent. More preferably, the recovery device 31 adjusts the temperature of the condensing surface 31a based on the temperature measured by the thermometer 32.

  In order to further dry the film 26, a tenter chamber 60 and a drying chamber 61 are installed on the downstream side of the casting chamber 20 (see FIG. 1). Drying while stretching the width direction of the film by the tenter dryer 62 of the tenter chamber 60 is preferable in order to make the surface shape of the film 26 uniform. Further, the film 26 is fed into the drying chamber 61 where a large number of rollers 63 are arranged. The film 26 is dried while being conveyed while being wound around the rollers 63. Further, the film 26 is preferably cooled to about room temperature in the cooling chamber 64. It is preferable to wind up with the winder 65 after that. In addition, before winding in this invention, an ear cut may be performed or a knurling may be provided. Moreover, the film forming line 10 used for the solution casting film forming method concerning this invention is not limited to what was shown in FIG.

  The solution casting film forming method of the present invention is most suitable for the film forming method of a film (thin film) formed to a thickness in the range of 20 μm to 120 μm because the film stress at the time of peeling is large.

  Although FIG. 1 shows a form in which one kind of dope is cast in a single layer, the present invention is not limited to the illustrated form. For example, it can be applied to a co-casting method in which a feed block is attached upstream of a casting die, a large number of dopes are fed into the feed block, and the dopes are merged and cast in the feed block. Is possible. In the figure, the rotary drum 22 is shown as a support. However, the present invention is not limited to the illustrated embodiment, and can also be applied to a solution casting film forming method in which a dope is cast on a casting belt that runs endlessly by a rotating roller, for example.

[Film 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 to 5% is particularly preferred. When stretching for the purposes of both (1) and (2) or only for the purpose of (2), stretching is performed at a relatively low temperature and a stretching 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 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.

(Optical properties of the film)
Preferred optical properties of the film of the present invention vary depending on the use 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 above Re and Rth are values measured at a wavelength of 590 nm.

  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) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments). In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like.

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 (rotation axis) (in the absence of the slow axis, any in-plane value) The light of wavelength λ nm is incident from each of the inclined directions in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction (with the direction of the rotation axis as the rotation axis). KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the 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 its 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. .

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 optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is the above-mentioned Re (λ), and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) from −50 degrees to +50 degrees with respect to the film normal direction. The light of wavelength λ nm is incident from each inclined direction in 10 degree steps 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 WR is calculated.

  In the above measurement, as the assumed value of the average refractive index, 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 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.

[Physical properties of polymer film]
When the film of the present invention is used as a protective film for a polarizing plate, the photoelasticity value is 0.5 × 10 ^{−13 to} 9.0 × 10 ⁻¹³ [cm ² / dyn], and the moisture permeability value (however, The film thickness converted to 80 μm is preferably 180 to 435 [g / cm ² 24h]. 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]. Further, 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 this invention has the said characteristic, when it uses as a protective film of a polarizing plate, the fall of the performance by the influence of humidity can be reduced.

[Polarizer]
The polarizing plate of the present invention has at least the film of the present invention and a polarizing film. Usually, a polarizing plate has a polarizing film and two protective films arranged on both sides thereof. The film of the present invention can be used as both or one protective film. For the other protective film, a normal cellulose acetate film or the like may be used. Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film 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 surface treatment as described later, and then the film-treated surface and the polarizing film 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 polarizing film and protective films for protecting both surfaces of the polarizing film. Further, the polarizing plate is composed of a protective film on one surface of the polarizing plate and a separate film on the other 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. It is preferable that the film of the present invention is bonded to the polarizing film so that the transmission axis of the polarizing film coincides with the slow axis of the film.

(Film surface treatment)
In this invention, in order to improve the adhesiveness of a polarizing film and a protective film, it is preferable to surface-treat the surface of a 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 the surface treatment, the preferable range varies depending on the type of the 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 the polarizing film 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 a medium 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 transparent support in order to impart physical strength to the protective film provided with the antireflection layer. In particular, it is preferably provided between the transparent 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. Although it is possible to give a volume resistivity of 10 ⁻⁸ (Ωcm ⁻³ ) by using a hygroscopic substance, a water-soluble inorganic salt, a certain surfactant, a cationic polymer, an anionic polymer, colloidal silica or the like, 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.

[Image display device]
The film of the present invention, a retardation film comprising the film, and a polarizing plate using the film can be used for image display devices, particularly 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.

In the following examples and comparative examples, various measurements were performed as follows.
(1) Molecular weight and molecular weight distribution: Gel permeation chromatography (GPC, manufactured by Tosoh Corporation, trade name: HLC-8020 / four columns: manufactured by Tosoh Corporation, trade name: TSKguardcolumn SuperHZ-H, TSKgel SuperHZM-H, The mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) in terms of standard polystyrene were determined using tetrahydrofuran (THF) solvent using TSKgel SuperHZ4000 and TSKgel SuperHZ2000). Mn represents the number average molecular weight.
(2) Polymer molecular structure: 1HNMR or 13CNMR was measured in deuterated methylene chloride using a superconducting nuclear magnetic resonance absorber (NMR, manufactured by Bruker, trade name: AVANCE400).
(3) Monomer purity: Purity was determined using a gas chromatograph (GC, manufactured by Shimadzu Corporation, trade name: GC-2010, column tube: DB17 30m 0.25φ).
(4) Re, Rth: Using a phase difference measuring device (manufactured by Oji Scientific Instruments, trade name: KOBRA 21ADH), the wavelength was measured at 590 nm by the method described above.

[Synthesis of norbornene compounds]
(Synthesis Example 1: Synthesis of M-1)
Dicyclopentadiene (manufactured by Wako Pure Chemical Industries, Ltd.) 10940 g, allyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.) 17720 g and hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.) 10 g were charged into the 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 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 M-1. The purity was 99.9% and the endo / exo ratio was 83/17.

(Synthesis Example 2: Synthesis of M-2)
The autoclave was charged with 12480 g of dicyclopentadiene (manufactured by Wako Pure Chemical Industries, Ltd.), 16240 g of methyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) and 10 g of hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.), and the air gap was replaced with nitrogen. The mixture was stirred for 4 hours at an internal temperature of 210 ° C. in a closed system (rotational speed = 300 rpm). The residue was subjected to precision distillation (column length = 120 cm, column packing = Propak, reflux ratio = 10/1, pressure = 10 mmHg, top temperature = 85 ° C.) to obtain colorless and transparent M-2. The purity was 99.7% and the endo / exo ratio was 45/55.

(Synthesis Example 3: Synthesis of M-3)
A colorless and transparent M-3 was obtained in the same manner as in Synthesis Example 2 except that methyl acrylate was changed to ethyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) in Synthesis Example 2. The purity was 99.5% and the endo / exo ratio was 45/55.

(Synthesis Example 4: Synthesis of M-4)
Norbornene carboxylic acid was synthesized from M-2 with reference to WO 2005/089549 pamphlet. This is described in J. Org. Am. Chem. Soc. , 127, 14536-14537 (2005), and M-4 was synthesized. The purity was 99.4% and the endo / exo ratio was 45/55.

(Synthesis Example 5: Synthesis of M-5)
J. et al. Organomet. Chem. , 680, 263-270 (2003), M-5 was synthesized. The purity was 99.6% and the endo / exo ratio was 74/26.

(Synthesis Example 6: Synthesis of M-6)
M-6 was synthesized with reference to Synthesis Example 3 of JP-A No. 2000-154169. The purity was 99.3% and the endo / exo ratio was 45/55.

[Catalyst synthesis]
(Synthesis Example 7: Synthesis of S-1)
[Pd (C ₃ H ₅ ) Cl] ₂ (manufactured by Aldrich) and tricyclohexylphosphine (manufactured by Strem) were used. Am. Chem. Soc. , 118, 6225-6234 (1996), S-1 was synthesized.

[Synthesis of norbornene-based addition polymer]
(Example 1: Synthesis of P-1 (99/1))
200 mL of purified toluene, monomer M-2 (198 g) and monomer M-4 (2 g) were charged into a reaction vessel. Next, 167 μL of catalyst S-1 (87 mg) dissolved in 6 mL of toluene, 167 μL of tributylallyl tin (manufactured by Aldrich), and 316 mg of dimethylanilinium tetrakispentafluorophenyl borate (manufactured by Strem) dissolved in 3 mL of methylene chloride were charged into the reaction vessel. did. Heating was started and the mixture was stirred at 100 rpm for 18 hours at 300 rpm. During this time, toluene was added as appropriate with an increase in the viscosity of the reaction solution. The obtained reaction solution was put into excess methanol to precipitate a polymer. The precipitate was collected and washed with methanol. The resulting polymer was vacuum dried at 110 ° C. for 6 hours. 182 g (yield 91%) of a white solid was obtained.
The obtained polymer was dissolved in tetrahydrofuran, and the mass average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (polystyrene conversion). As a result, Mn = 73900 and Mw = 150200. ^{When 13} C-NMR was measured and the copolymerization ratio was determined from the carbonyl carbon in the side chain, it was as follows. This polymer is designated as P-1 (99/1).

(Example 2: Synthesis of P-1 (97/3))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-2 (194 g) and M-4 (6 g). Mn = 84500 and Mw = 186200. The copolymerization ratio was as follows. This polymer is designated as P-1 (97/3).

(Example 3: Synthesis of P-1 (90/10))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-2 (182 g) and M-4 (18 g). Mn = 78500 and Mw = 168200. The copolymerization ratio was as follows. This polymer is designated as P-1 (90/10).

(Example 4: Synthesis of P-1 (82/18))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-2 (163 g) and M-4 (37 g). Mn = 78700 and Mw = 167200. The copolymerization ratio was as follows. This polymer is designated as P-1 (82/18).

(Example 5: Synthesis of P-1 (50/50))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-2 (105 g) and M-4 (95 g). Mn = 87600 and Mw = 175200. The copolymerization ratio was as follows. This polymer is designated as P-1 (50/50).

(Example 6: Synthesis of P-1 (39/61))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-2 (85 g) and M-4 (115 g). Mn = 75700 and Mw = 168200. The copolymerization ratio was as follows. This polymer is designated as P-1 (39/61).

(Example 7: Synthesis of P-2 (85/15))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-2 (160 g) and M-5 (40 g). Mn = 68200 and Mw = 146400. The copolymerization ratio was as follows. This polymer is designated as P-2 (85/15).

(Example 8: Synthesis of P-3 (91/9))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-3 (177 g) and M-6 (23 g). Mn = 60100 and Mw = 120900. The copolymerization ratio was as follows. This polymer is designated as P-3 (91/9).

(Example 9: Synthesis of P-4 (89/11))
A polymer was obtained in the same manner as in Example 1 except that the monomer of Example 1 was changed to M-1 (183 g) and M-4 (17 g). Mn = 105400 and Mw = 215600. The copolymerization ratio was as follows. This polymer is designated as P-4 (89/11).

(Examples 10 to 18)
The polymers obtained in Examples 1 to 9 were dissolved in methylene chloride / methanol / butanol / water (83/16 / 0.6 / 0.4 mass ratio) to give a solid content concentration of 22%. This was pressure filtered. The obtained dope was cast and formed on an SUS plate set at −5 ° C., −10 ° C., and −20 ° C. with A3 size using an applicator (clearance 800 μm). This was left for 10 seconds, and a film peelability test was performed. The results of the polymer type, the temperature of the SUS plate, and the peelability are shown in Examples 10 to 18 in Table 1.

(Comparative Example 1: Synthesis of P-5)
6000 mL of purified toluene and monomer M-1 (1190 g) were charged into a reaction vessel. Next, 480 mg of palladium acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 100 mL of toluene, 460 mg of tricyclohexylphosphine (manufactured by Strem), and 2560 mg of dimethylanilinium tetrakispentafluorophenylborate (manufactured by Strem) dissolved in 100 mL of methylene chloride. Was charged into the reaction vessel. Heating was started and stirred at 90 ° C. for 6 hours at 300 rpm. During this time, toluene was added as appropriate with an increase in the viscosity of the reaction solution. The obtained reaction solution was put into excess methanol to precipitate a polymer. The precipitate was collected and washed with methanol. The resulting polymer was vacuum dried at 110 ° C. for 6 hours. 1130 g (yield 95%) of a white solid was obtained. Mn = 105600 and Mw = 350400. This polymer is designated as P-5.

(Comparative Example 2: Synthesis of P-6)
Purified toluene 550 mL and monomer M-2 (550 g) were charged into a reaction vessel. Next, 460 mg of catalyst S-1 (239 mg) dissolved in 20 mL of toluene, 460 μL of tributylallyl tin (manufactured by Aldrich) and 868 mg of dimethylanilinium tetrakispentafluorophenylborate (manufactured by Strem) dissolved in 20 mL of methylene chloride were charged into the reaction vessel. did. Heating was started and the mixture was stirred at 100 rpm for 18 hours at 300 rpm. During this time, toluene was added as appropriate with an increase in the viscosity of the reaction solution. The obtained reaction solution was put into excess methanol to precipitate a polymer. The precipitate was collected and washed with methanol. The resulting polymer was vacuum dried at 110 ° C. for 6 hours. 516 g (94% yield) of a white solid was obtained. Mn = 102400 and Mw = 219700. This polymer is designated as P-6.

(Comparative Example 3: Synthesis of P-7)
The polymer was synthesized in the same manner as in Comparative Example 2 except that the monomer in Comparative Example 2 was changed to M-3 (600 g) to obtain 450 g (yield 75%) of a polymer. Mn = 100400 and Mw = 208600. This polymer is designated as P-7.

(Comparative Example 4: Synthesis of P-8)
P-8 was synthesized with reference to JP-A No. 2002-20435. Mn = 53,000 and Mw = 12,000.

(Comparative Examples 5 to 8)
A dope was produced from the polymers synthesized in Comparative Examples 1 to 4 in the same manner as described above, and a peelability test was performed. The results are shown in Comparative Examples 5 to 8 in Table 1.

Amide group ratio = Mole number of amide group-containing unit / Ester or acyloxy group-containing unit and total number of moles of amide group-containing unit Solubility evaluation:
Completely dissolved, transparent dope (◎)
Dissolved but dope is not completely transparent (○)
Does not dissolve (×)
Stripping evaluation:
No peeling residue (◎)
Although peeling off occurred, 1% or less of film area (○)
Stripping residue is larger than 1% of the film area (×)

  From the above results, it can be seen that the polymer of the present invention has a cooling gelling ability. On the other hand, the polymer of the comparative example does not have cooling gelation ability.

(Example 19: High-speed casting film formation)
In a mixed solvent of methylene chloride / methanol / butanol / water (83/16 / 0.6 / 0.4 mass ratio), 26.8 parts by mass of P-1 (90/10), triphenyl phosphate (TPP) 2 0.1 parts by mass, 1.1 parts by mass of biphenyl diphenyl phosphate (BDP), and 0.13 parts by mass of Irganox 1010 (IRG1010: manufactured by Ciba Geykey) were added and prepared by a known method. The solid content concentration was 23% by mass. In addition, in this invention, the mass part of a solute means the mass ratio when a mixed solvent is 100 mass parts.

  The film was formed using the film forming line 10 of FIG. As the casting die 23, a coat hanger type die was used. Further, mirror finishing was performed so that the surface roughness of the rotating drum 22 as a support was 0.04S. By supplying the refrigerant from the refrigerant supply device 45 to the rotating drum 22, the surface temperature was kept at −5 ° C. Further, in order to set the peripheral speed ratio (V1 / V0) to 1.1, the peripheral speed V0 (casting speed) of the rotating drum is set to 100 m / min, and the peripheral speed V1 of the peeling roller 25 is set to 110 m / min. did. The clearance C1 between the rotating drum 22 and the peeling roller 25 was 5 mm. The first gas 28 is blown at a wind speed of 1 m / s and a temperature of 35 ° C., the second gas 30 is blown at a wind speed of 5 m / s and a temperature of 80 ° C., and the third gases 48 and 49 are blown at a wind speed of 5 m / s and a temperature of 25 ° C. It was.

  After setting the above-described conditions, the dope 12 at 30 ° C. was cast on the rotating drum 22 so that the film 26 after drying had a thickness of 80 μm. When the gel film 24 was visually observed at the time of peeling, no peeling occurred and no increase in the peeling position was observed. Further, the film 26 was dried at 135 ° C. for 3 minutes by a tenter dryer 62, then dried at a drying zone 61 at 135 ° C. for 10 minutes, and then cooled in a cooling chamber 64 at 80 ° C. for 1 minute. Finally, it was wound up by a winder 65. Furthermore, when the surface of the film 26 was visually observed, it was found that the smoothness was extremely good. This film formation was carried out continuously for 48 hours, but no peeling was observed on the drum.

(Examples 20 to 25: high-speed casting film formation)
P-1 (97/3), P-1 (82/18), P-1 (50/50), P-2 (85/15), P-3 (91/9), P-4 (89 / 11) was formed in the same manner as in Example 19. In any case, the film was smooth and the film was continuously formed for 48 hours, but no peeling residue was found on the drum.

(Comparative Example 9: High-speed casting film formation)
P-5 was casted in the same manner as in Example 19, but could not be peeled off from the drum and casted.

(Comparative Examples 10-11: High-speed casting film formation)
P-6 and P-7 were casted in the same manner as in Example 19, but could not be peeled off from the drum and casted.

(Examples 26 to 32)
P-1 (90/10), P-1 (97/3), P-1 (82/18), P-1 (50/50), P-2 (85) obtained in Examples 19 to 25 / 15), P-3 (91/9), and P-4 (89/11) films were measured for retardation at a wavelength of 590 nm. The thickness of the film was measured at three points on an arbitrary portion with a digital micrometer, and the average value d was taken. From the following formula, Re and Rth having a film thickness of 80 μm were obtained. The results are shown in Table 2 below.
Re = actual measurement Re / d × 80
Rth = measured Rth / d × 80

  As described above, the polymer of the present invention can be cast at high speed. In particular, it is preferable that the ratio of the amide group is 0.03 to 0.50 because the solubility is good. On the other hand, the polymer of the comparative example cannot be cast at high speed.

It is the schematic of the film film forming line used for the solution film forming method concerning this invention. It is the principal part expansion schematic of the film film forming line shown in FIG. It is the principal part expansion schematic of the film film forming line shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Film forming line 11 Mixing tank 12 Dope 13 Stirring blade 14 Pump 15 Filter 19 Drying air 20 Casting chamber 21 Casting die 22 Rotating drum 22a Landing wire 22b Stripping wire 22c Gel-free membrane surface 23 Casting bead 23b Flow Expanded bead back surface 24 Gel film 25 Stripping roller 26 Film 27 Gas supply device 27a Gas pipeline 28, 30, 48, 49 Gas 29 Blower 31 Recovery device 31a Condensing surface 32 Thermometer 40, 41 Support rotating shaft 42, 43 Bearing 44 Refrigerant 45 Refrigerant supply device 60 Tenter chamber 61 Drying chamber 62 Dryer 63 Roller 64 Cooling chamber 65 Winding machine C1 Clearance

Claims (9)

A norbornene-based addition polymer containing at least one repeating unit represented by the following general formula (1A) and at least one repeating unit represented by the following general formula (1B).

(In General Formula (1A) and General Formula (1B), R ^{1 to} R ⁴ each independently represents a hydrogen atom or a substituent. L ¹ and L ² each independently represents a single bond or a divalent linking group. M and p are each independently an integer of 0 or 1, n and q are each independently an integer of 1 to 4, r and s are each independently an integer of 1 to 3, where r and s are 2 In these cases, R ¹ and R ³ may be the same or different from each other, A represents COOR ⁵ or OCOR ⁵ , and R ⁵ represents a substituent.)   The ratio of the total mole number x of the repeating unit represented by the general formula (1A) to the total mole number y of the repeating unit represented by the general formula (1B) is 0.03 ≦ y / (x + y) ≦ 0. The norbornene-based addition polymer according to claim 1, which is 50.   The norbornene-based addition polymer according to claim 1 or 2, wherein m and p are 0 and n and q are 1. The L ¹ and L ² are single bonds, R ¹ and R ³ are hydrogen atoms, A is COOR ⁵ and R ⁵ is an alkyl group having 1 to 4 carbon atoms. The norbornene-based addition polymer described.   The optical material containing the norbornene-type addition polymer in any one of Claims 1-4.   The optical material according to claim 5, wherein the optical material has a thin film, film, or sheet shape. The optical material according to claim 5 or 6, wherein Re and Rth are in the following ranges.
(1) 0 ≦ Re ≦ 100 nm
(2) 0 ≦ Rth ≦ 400 nm
(In the formula, Re and Rth represent in-plane retardation (Re) and retardation in the thickness direction (Rth) at a wavelength of 590 nm.)   A polarizing plate comprising a polarizing film and protective films provided on both sides of the polarizing film, wherein at least one of the protective films is the optical material according to claim 5.   The image display apparatus containing the optical material in any one of Claims 5-7, or the polarizing plate of Claim 8.

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