WO2007001020A1 - Method for producing optical film, optical film and polarizing plate - Google Patents

Abstract

Disclosed is an optical film exhibiting various optical characteristics, heat resistance and cohesion/adhesion to other materials of a thermoplastic norbornene resin. This optical film is controlled so that the optical axis in the film thickness is tilted. Also disclosed are a method for producing such an optical film and a polarizing plate using such an optical film. Specifically disclosed is a method for producing an optical film wherein a melt-extruded thermoplastic norbornene resin film is passed between two rolls having different peripheral velocities so that the optical axis in the film thickness direction is tilted. Also disclosed are an optical film obtained by such a production method, and a polarizing plate having a structure wherein a protective film is arranged on each side of a polarizing film and the optical film is used as at least one of the protective films.

Description

 Optical film manufacturing method, optical film and polarizing plate

 Technical field

 The present invention relates to an optical film production method useful as a specific retardation film comprising a thermoplastic norbornene-based resin, an optical film, and a polarizing plate.

 Background art

 [0002] Thermoplastic norbornene resin is amorphous and has high light transmittance due to the presence of bulky groups in the main chain structure with a high glass transition temperature due to the rigidity of the main chain structure. It has features such as low birefringence due to its low refractive index anisotropy, and is attracting attention as a transparent thermoplastic resin excellent in heat resistance, transparency and optical properties.

 As a strong thermoplastic norbornene resin, various structures have been proposed (see, for example, Patent Document 1 to Patent Document 6).

 [0003] In recent years, thermoplastic norbornene-based resin has been applied in the fields of optical materials such as optical discs, optical lenses, optical fibers, and sealing materials such as optical semiconductor sealing, utilizing the above-described features. To be considered. In addition, attempts have been made to improve the problems of conventional optical films by applying them to optical films as shown below.

 [0004] Conventionally, a film made of polycarbonate, polyester, triacetyl acetate, or the like used as an optical film has a large photoelastic coefficient, and therefore changes due to a slight difference in stress. However, because of problems such as heat resistance and water absorption deformation, films made of thermoplastic norbornene resin have been proposed as various optical films. For example, Patent Documents 7 to 9 describe retardation plates made of a film cover made of thermoplastic norbornene-based resin. Patent Documents 10 to 13 describe that a film made of a thermoplastic norbornene-based resin is used as a protective film for a polarizing plate.

[0005] These patent documents describe that a thermoplastic norbornene-based resin having a water absorption rate of 0.05% or less can be easily obtained, and that it is characterized and necessary in terms of low water absorption. Has been. However, when using a film made of such a low water-absorbing thermoplastic norbornene-based resin as, for example, a retardation plate or a substrate for a liquid crystal display element, a hard coat layer formed on the surface thereof, There may be a problem with the adhesion to the antireflection film or the transparent conductive layer, or the adhesion to the polarizing plate or glass. In addition, when used as a protective film for a polarizing plate, in addition to the above problems, a water-based adhesive is usually used for pasting with a polarizing film, so that the water in the water-based adhesive is dried. The problem of difficulty also arises.

 [0006] Thermoplastic norbornene-based resin has various structures, and the water absorption of all the thermoplastic norbornene-based resins is not necessarily 0.05% or less, and the water absorption is 0.00. In order to obtain a thermoplastic norbornene-based resin of 05% or less, the thermoplastic norbornene-based resin should have a structure having only a carbon atom and a hydrogen atom, or a halogen atom instead of a part of hydrogen. It was necessary to make it the structure of containing.

 Therefore, in order to solve the above-mentioned problems due to low water absorption, an optical film containing a thermoplastic norbornene-based resin in which a polar group is introduced in the molecule has been proposed (for example, patent document). 14 and Patent Document 15;)). These optical films have excellent optical properties such as high transparency, small retardation given to transmitted light, and uniform and stable retardation when stretched and oriented. In addition to having the advantage of having good heat resistance, adhesion to other materials and adhesiveness, etc., and also having the advantage of small water-absorbing deformation, resulting in the manufacturing method of the optical film, The optical axis had to be approximately parallel to the film normal direction.

[0007] In addition, with the recent increase in the size of liquid crystal displays and the adoption of liquid crystal panels in television monitors, liquid crystal display elements such as viewing angle perception, which has a higher definition and a higher luminance contrast ratio, are available. What has the outstanding optical characteristic is requested | required. In addition, various types of liquid crystal modes (liquid crystal alignment states) in liquid crystal panels have been proposed and adopted. Under these circumstances, films with a tilted optical axis in the film thickness direction have been proposed for liquid crystal cells of the twisted nematic (TN) mode and the OCB mode having a bent structure. However, in order to obtain such a film, it is necessary to apply a liquid crystal such as a discotic liquid crystal on a film substrate (see, for example, Patent Document 16 and Japanese Patent Application Laid-Open No. H10-260260). See Permitted Document 17. ) As a result, it becomes a two-layer structure with a base film having a retardation, which causes inconvenience when used as a viewing angle compensation film, and it is difficult to obtain characteristics sufficient for the liquid crystal itself. There was a problem.

[0008] Furthermore, it has been attempted to forcibly shear the film during film formation to incline the optical axis in the film thickness direction (see, for example, Patent Document 18 and Patent Document 19). In terms of surface properties and thickness uniformity, as well as uniformity and stability of retardation characteristics, they were never satisfactory.

 Patent Document 1: Japanese Patent Application Laid-Open No. 11-132625

 Patent Document 2: JP-A-11132626

 Patent Document 3: Japanese Patent Laid-Open No. 63-218726

 Patent Document 4: JP-A-2-133413

 Patent Document 5: Japanese Patent Laid-Open No. 61-120816

 Patent Document 6: Japanese Patent Laid-Open No. 61-115912

 Patent Document 7: Japanese Patent Laid-Open No. 245202

 Patent Document 8: JP-A-5-2108

 Patent Document 9: JP-A-5-64865

 Patent Document 10: Japanese Patent Laid-Open No. 5-212828

 Patent Document 11: JP-A-6-51117

 Patent Document 12: Japanese Patent Laid-Open No. 7-77608

 Patent Document 13: Japanese Patent Laid-Open No. 5-61026

 Patent Document 14: Japanese Patent Laid-Open No. 7-287122

 Patent Document 15: Japanese Patent Laid-Open No. 7-287123

 Patent Document 16: JP-A-9--117983

 Patent Document 17: Japanese Patent Laid-Open No. 10-206637

 Patent Document 18: Japanese Patent Laid-Open No. 2001-166134

 Patent Document 19: Japanese Patent Laid-Open No. 2003-25414

 Disclosure of the invention

Problems to be solved by the invention [0010] The present invention has been made based on the circumstances as described above, and its purpose is to provide various optical properties, heat resistance and adhesion to other materials possessed by the thermoplastic norbornene-based resin. The object is to provide an optical film that exhibits adhesiveness and the like, and whose strength is controlled so that the optical axis in the thickness direction of the film is inclined, a manufacturing method thereof, and a polarizing plate using the optical film.

 Means for solving the problem

 [0011] The present invention is characterized in that an optical axis in the film thickness direction is inclined by passing a melt-extruded thermoplastic norbornene-based resin film between two rolls having different peripheral speeds. The ratio of the peripheral speeds of the two rolls (the peripheral speed of roll 1 and the peripheral speed of roll 2) is not less than 0.75 and not less than 0.99. The power to be below!

 Of the two rolls, the surface of the roll having a low peripheral speed is preferably made of rubber.

 Furthermore, in the method for producing an optical film of the present invention, it is preferable to perform stretching at Tg—15 ° C. to Tg + 10 ° C. based on the glass transition temperature (Tg) of the thermoplastic norbornene-based resin.

 Next, the present invention relates to an optical film obtained by the above method, which is a thermoplastic norbornene-based resin film, and the optical axis in the film thickness direction is inclined by 3 to 40 degrees. Here, the in-plane retardation (RO) of the optical film is preferably 5 to 300 nm.

 Next, the present invention relates to a polarizing plate having a configuration in which a protective film is laminated on each of both surfaces of a polarizing film, and the protective film laminated on at least one surface of the polarizing film is the optical film.

 The invention's effect

[0012] The optical film obtained by the present invention exhibits high transparency, low retardation, and other optical properties, heat resistance and adhesion to other materials'adhesiveness, etc. possessed by a thermoplastic norbornene-based resin. In addition, it has the characteristic that water absorption deformation is small, and the force is also high during tough processing and use. It is a thin film in which the handleability at the time of use is good and the retardation in the film thickness direction is adjusted together with the retardation in the film plane, and it has retardation uniformity and stable retardation characteristics.

 Such an optical film of the present invention can be provided with a light diffusing function and can be laminated with a transparent conductive layer or an antireflection layer.

 The polarizing plate of the present invention is obtained by using the above optical film as a protective film, and since the optical film has a protective function and a retardation providing function, it was used for a liquid crystal display element or the like. In this case, the number of parts can be reduced as compared with the conventional case. Therefore, according to the optical film and the polarizing plate of the present invention, a liquid crystal display element made of VA type liquid crystal can be manufactured with high production efficiency, and an optimum viewing angle characteristic can be obtained for the obtained liquid crystal display element. In addition, the thin film can be miniaturized.

 BEST MODE FOR CARRYING OUT THE INVENTION

[0013] The method for producing an optical film of the present invention is more than the glass transition temperature (Tg) of the thermoplastic norbornene-based resin in the method of producing thermoplastic norbornene-based resin in an optical film by a melt extrusion method. It is characterized in that the optical axis in the thickness direction of the film is inclined by applying shear shear between at least two rolls in the transition state from T to below Tg.

 [0014] The optical film of the present invention is composed of a thermoplastic norbornene-based resin. The thermoplastic norbornene-based resin for obtaining this optical film is shown in the following (i) to (e). (Co) polymer (hereinafter also referred to as “specific polymer”).

 (I) A ring-opened polymer of a compound represented by the following general formula (1) (hereinafter also referred to as “specific monomer a”).

 (Mouth) A ring-opening polymer of a specific monomer a and a compound copolymerizable with the specific monomer a (hereinafter also referred to as “copolymerizable monomer”).

 (C) A hydrogenated product of the ring-opening polymer of (i) or the ring-opening polymer of (mouth).

(2) A compound obtained by cyclization of the ring-opened polymer of (i) above or the ring-opened polymer of (mouth) by Friedel-Craft reaction or a hydrogenated product thereof. (E) An addition type polymer of the specific monomer a or an addition type polymer of the specific monomer a and an unsaturated double bond-containing compound or a hydrogenated product thereof.

[0015] [Chemical 1]

 …… (1)

[In the formula, m is an integer of 1 or more, p is 0 or an integer of 1 or more, and I ^ to R ⁴ are independently a hydrogen atom; a halogen atom; an oxygen atom, a nitrogen atom, It has a linking group containing an atom or a key atom, and represents a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a polar group. Furthermore, R ¹ and R ² , R ³ and R ⁴ or R ² and R ³ are bonded to each other to form a carbocyclic or heterocyclic ring having a monocyclic structure or a polycyclic structure condensed with other rings. The formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

 The specific polymer uses a compound represented by the following general formula (2) as a copolymerizable monomer (hereinafter also referred to as “specific monomer b”), and is specified as specific monomer a. It is preferably obtained by copolymerizing with the monomer b. According to the specific polymer having such a configuration, the finally obtained optical film has more excellent mechanical properties such as toughness, and is required for the optical film by extrusion or stretching. It becomes easier to obtain the optical axis tilt and phase difference in the desired thickness direction.

 [0018] [Chemical 2]

 …… (2)

[In the formula, each of I ^ to R ⁴ independently represents a hydrogen atom; a halogen atom; an oxygen atom, or a nitrogen atom. Or a linking group containing a thio atom or a key atom; a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a polar group. In addition, R ¹ and R ² , R ³ and R 4 or R ² and R ³ are bonded to each other to form a carbocyclic or heterocyclic ring having a monocyclic structure or a polycyclic structure fused with another ring (however, in general The carbocycle or heterocycle formed which may form (except for the structure represented by the formula (1)) may be an aromatic ring or a non-aromatic ring. ]

 [0020] Further, the specific polymer is a ring-opening polymer of the specific monomer a and the specific monomer b, and is derived from the specific monomer a represented by the general formula (1). A structural unit (hereinafter also referred to as “structural unit a”) and a structural unit derived from the specific monomer b represented by the general formula (2) (hereinafter also referred to as “structural unit b”). It is preferable. The specific polymer having such a configuration is preferred because it can balance heat resistance and heat processability by stretching.

 [0021] Examples of the halogen atom in the general formulas (1) to (2) include a fluorine atom, a chlorine atom, and a bromine atom.

 Examples of the hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as a methyl group, an ethyl group, and a propyl group; cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group; a bur group, an aryl group, and a pro group. Examples thereof include a alkenyl group such as a phenyl group.

[0022] Further, the substituted or unsubstituted hydrocarbon group in the general formula (1) to the general formula (2) may be directly bonded to the ring structure, or via a linkage. Please join and hurry.

 Examples of the linking group include a divalent hydrocarbon group having 1 to 10 carbon atoms [for example, — (CH

 2

)-(Wherein q is an integer of 1 to 10)]; a linking group containing an oxygen atom, a nitrogen atom, a nitrogen atom or a silicon atom [for example, a carbonyl group (one CO-) , Oxycarbon groups (—O (CO) −), sulfone groups (—so—), ether bonds (—o—),

 2

Ether bond (—S—), imino group (one NH—), amide bond (one NHCO—, —CONH —), siloxane bond (—OSi (R ⁵ )-(where R ⁵ is methyl, ethyl, etc.) Alkyl group)

 2

 Or a combination of two or more of these.

[0023] Examples of the polar group include a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, and an alkoxy force. Carbonyl group, aryloxycarbol group, cyano group, amide group, imide ring-containing group, triorganosiloxy group, triorganosilyl group, amino group, acyl group, alkoxysilyl group, sulfonyl-containing group, and carboxyl Groups and the like. More specifically, examples of the alkoxy group include a methoxy group and an ethoxy group; examples of the alkoxy carbo group include a methoxy carbo group and an ethoxy carbo group; Examples of the aryloxycarbol group include a phenoxycarbon group, a naphthyloxycarbonyl group, a fluorocarboxyl group, and a biphenyloxycarbol group; examples of the triorganosiloxy group include trimethylsiloxy group and trie Examples of the triorganosilyl group include a trimethylsilyl group and a triethylsilyl group; examples of the amino group include a primary amino group; examples of the alkoxysilyl group include a trimethoxysilyl group and a triethoxy group. A silyl group etc. are mentioned. As a specific example of the specific monomer a,

Tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene,

Pentacyclo [9.2.1. I ³ ' ⁹ .0 ² ' ¹ .0 ⁴ ' ⁸ ] — 12 pentadecene,

Pentacyclo [9.2.1. I ⁵ ' ⁸ .0 ² ' ¹ .0 ⁴ ' ⁹ ] — 12 pentadecene,

8-Methoxycarbotetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 Dodecene,

8 ethoxycarbotetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene,

8— n-propoxycarborutetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 Dodecene, 8-isopropoxycarborutetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene, 8— n-butoxycarborutetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene, 8 phenoxycarborutetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 Dodecene, 8-Methyl 8-Carboxymethyltetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 Dodecene,

8-Methyl 8 ethoxycarbotetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 Dodecene,

8-methyl-8-n-propoxy-carbonitrile - Rutetorashikuro ^{[. 4.4.0 I 2 '5'} I 7 '10] -3 ~ dodecene,

8-Methyl 8-Isopropoxycarborutetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] -3- Dodecene,

 8-methyl-8-n-butoxycarbonyltetracyclo [4.4.0. 1] 3-dodecene,

8-methyl 8 Fuenokishikarubo - Rutetorashikuro ^{[4.4.0 I 2 '5 .1 7} ' 1 (>.] - 3 dodecene,

8 ethylidenetetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene,

8 Phenoltetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 Dodecene,

8-Methyl-8-phenyltetracyclo [4.4.0. ] _—3 dodecene,

[0025] 8 Fluorotetracyclo [4.4.0.] 1 3-dodecene,

 8 Fluoromethyltetracyclo [4.4.0. 3—dodecene, 8 [.4.0. -3—dodecene, 8 trifluoromethyltetracyclo [4.4.0. —3—dodecene 8 [4.4.0.] 3-Dodecene, 8 8 difluorotetracyclo [4.4.0.] One 3-Dodecene,

 8 9-difluorotetracyclo [4.4.0.] 1-3-dodecene,

 8 8 bis (trifluoromethyl) tetracyclo [4.4.0. Dodecene, 8 9 bis (trifluoromethyl) tetracyclo [4.4.0. Dodecene, 8 -methyl mono 8 trifluoromethyltetracyclo [4.4.0. -3—Dodecaen,

[0026] 8 8, 9 trifluorotetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene,

8 8, 9 Tris (trifluoromethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene,

8 8, 9, 9-tetrafluorotetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene, 8 8, 9, 9-tetrakis (trifluoromethyl) tetracyclo [4.4.0 I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 -dodecene,

8, 8 Difluoro-9, 9 Bis (trifluoromethyl) tetracyclo [4.4.0. I ² ' ^5. V'] —3-Dodecene,

8, 9 Difluoro-8, 9 Bis (trifluoromethyl) tetracyclo [4.4.0. I ² ' ^5. V i. ] One third

8, 8, 9 Trifluoro 9 Trifluoromethyltetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ]-3 -dodecene,

8, 8, 9 Trifluoro 9 Trifluoromethoxytetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] —3-Dodecene,

8, 8, 9 Trifluoro-9 pentafluoropropoxytetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3-dodecene,

8-Fluoro8-pentafluoroethyl 9,9-bis (trifluoromethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 Dodecene,

8, 9-difluoro 8—heptafluoro iso propinole 9 trifluoromethyltetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene,

8 kuroguchi 8, 9, 9 trifluorotetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3 dodecene

8, 9 Dichloro-1,8 bis (trifluoromethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] —3-Dodecene,

8- (2, 2, 2 trifnoreo ethoxycanolepo-nore) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] —3-dodecene,

 8—Methyl 8— (2,2,2 trifluoroethoxycarbonyl) tetracyclo [4.4.0. 2, 5 -.7, 10 „, 1,,,,

 1 .1] —3—Doessen

8— (4 biphenyl-carboxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3-dodecene,

8— (4 biphenyl-loxychetyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ]-3 -dodecene,

8-methyl 8- (4 biphenylcarbonyloxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3-dodecene,

8- (2-biphenyl-carboxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3-dodecene,

8—Methyl 8— (2 Biphenyl-carboxymethyl) tetracyclo [4.4.0. I ² ' ^5. L ⁷ ' ¹⁰ ] — 3-dodecene,

8- (3-biphenyl-carboxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3-dodecene,

8-methyl 8- (3-biphenyl-carboxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3-dodecene,

8- (1 naphthylcarbo-loxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] -3 dodecene,

8-methyl-8- (1-Nafuchirukarubo - Ruokishimechiru) tetracyclo ^{[4.4.0 I 2,5 I 7 '10} ..] - 3- dodecene,

8- (2 naphthylcarbo-loxymethyl) tetracyclo [4.4.0.I ² ' ⁵ .I ⁷ ' ¹⁰ ] -3 dodecene,

8-methyl-8- (2 Nafuchirukarubo - Ruokishimechiru) tetracyclo ^{[4.4.0 I 2,5 I 7 '10} ..] - 3- dodecene,

8- (9-anthracyl-carboxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] 1 3-dodecene,

8-methyl-8- (9-anthracyl-carboxymethyl) tetracyclo [4.4.0. I ² ' ^5. I ⁷ ' ¹⁰ ] — 3-dodecene,

 1, 2— (2H, 3H— [1, 3] epicyclopenta) 1, 2, Diels-Alder adducts of dihydroacenaphthylene and cyclopentagen

 The specific monomer a is not limited to these compounds. These compounds can be used as the specific monomer a alone or in combination of two or more.

Of these, compounds having at least one polar group in the molecule are preferred. In particular, in general formula (1), R ¹ and R ³ are hydrogen atoms or hydrocarbons having 1 to 10 carbon atoms. R ² and R ⁴ correspond to a hydrogen atom or a monovalent organic group, and at least one of R ² and R ⁴ is a polar group other than a hydrogen atom and a hydrocarbon group Good strength Adhesiveness with other materials' Adhesiveness is enhanced, which is preferable.

[0029] Here, the content of polar groups in the obtained specific polymer is determined by the optical film finally obtained. The structure is derived from the specific monomer a having a polar group in all structural units derived from the specific monomer a, although it is not particularly limited. The unit is preferably 1 mol% or more, more preferably 5 mol% or more, particularly preferably 10 mol% or more, and all structural units derived from the specific monomer a may have a polar group. Good.

[0030] Further, as the specific monomer a, in general formula (1), it is obtained that at least one of R ² and R ⁴ has a polar group represented by the following general formula (3). It is preferable in terms of easy control of the glass transition temperature, water absorption, and moisture permeability of the specific polymer.

(CH) COOR ⁶ (3)

 2 n

[Wherein, n is an integer of 0 to 5, and R ⁶ is a monovalent organic group. ]

In the general formula (3), specific examples of the monovalent organic group represented by R ⁶ include alkyl groups such as a methyl group, an ethyl group and a propyl group; a vinyl group and a naphthyl group. Group having an aromatic ring such as fluorenes such as diphenylsulfone and tetrahydrofluorene, and a heterocyclic ring such as furan ring and imide ring. Valent groups and the like.

 In the general formula (3), n is an integer of 0 to 5, preferably an integer of 0 to 2, and more preferably 0. The smaller the value of n, the higher the glass transition temperature of the specific polymer obtained, which is preferable. Particularly, the specific monomer a having n of 0 is preferable in terms of easy synthesis.

[0032] Furthermore, the specific monomer a is preferably one in which an alkyl group is further bonded to the carbon atom to which the polar group represented by the general formula (3) is bonded in the general formula (1). This makes it possible to balance the heat resistance, water absorption, and moisture permeability of the specific polymer obtained. Here, the number of carbon atoms of the alkyl group is preferably 1 to 5, more preferably 1 to 2, and particularly preferably 1.

 In addition, as the specific monomer a, one in which m is 1 and p is 0 in the general formula (1) is preferable because it has a high glass transition temperature and a specific polymer can be obtained.

[0033] Therefore, if the specific example of the specific monomer a described above is cited, 8-methyl-8-methoxycarbo-tetracyclo [4. 4. 0. I ² ' ^5. l ⁷ ' ¹⁰ ]-3 Dodesen is particularly preferred By using a specific monomer a such as the above, it has almost no adverse effects such as deformation due to water absorption having a high glass transition temperature, and has water absorption properties such that adhesion and adhesion with other materials are good. A specific polymer can be obtained.

On the other hand, specific examples of the specific monomer b include

 Bicyclo [2. 2. 1] heptoe-2-ene,

Tricyclo [5. 2. 1. 0 ² ' ⁶ ]

Tricyclo [6. 2. 1. 0 ² ' ⁷ ]

 5-methylbicyclo [2.2.1] hepto-2

 5 ethyl bicyclo [2.2.1] heptoe 2

 5-Methoxycarbo-bicyclo [2.2.1] hepto-2

 5-methyl 5-methoxycarbo-bibicyclo [2.2.1] hepto-2

5 Phenoxycarborubicyclo [2.2.1] hepto-2

 5-methyl-5-phenoxycarbo-bicyclo [2.2.1] hepto-2

5 Sheanobicyclo [2.2.1] Heptou 2

 5 ethylidenebicyclo [2. 2. 1] heptoe 2

 5 Huerbicyclo [2. 2. 1] heptoe 2

 5- (2 naphthyl) bicyclo [2.2.1] hepto-2en (α and j8), 5fluorobicyclo [2.2.1] hepto-2en,

 5 Fluoromethylbicyclo [2.2.1] hepto-2

 5 trifluoromethylbicyclo [2.2.1] heptone-2,

 5 Pentafluoroethyl bicyclo [2.2.1] hepto-2

[0035] 5, 5 Difluorobicyclo [2. 2. 1] Heptoen 2

 5, 6 Difluorobicyclo [2.2.1] Hepto-2

 5, 5 Bis (trifluoromethyl) bicyclo [2.2.1] hepto-2

 5, 6 bis (trifluoromethyl) bicyclo [2.2.1] hepto-2

 5-methyl-5-trifluoromethylbicyclo [2.2.1] hept-2-ene, 5, 5, 6-trifluorobicyclo [2.2.1] hept-2-ene,

5, 5, 6 Tris (fluoromethyl) bicyclo [2.2.1] hepto-2 5, 5, 6, 6—tetrafluorobicyclo [2.2.1] hepto-2

 5, 5, 6, 6-tetrakis (trifluoromethyl) bicyclo [2.2.1] hepto-2, 5,5 difluoro-6,6 bis (trifluoromethyl) bicyclo [2.2.1] Hepto 2—

 5, 6 difluoro-5, 6 bis (trifluoromethyl) bicyclo [2.2.1] hepto-2-ene,

 5, 5, 6 trifluoro 5 trifluoromethylbicyclo [2.2.1] hept-2-ene, 5-funoleo 5-pentafluoroethyl 6,6-bis (trifluoromethyl) bicyclo

[2. 2. 1] Heptou 2—

 5, 6-difluoro 5-heptafluoro isopropyl 6-trifluoromethylbicyclo [2.2.1] hepto-2-ene,

 5 Kuroguchi 1, 6, 6 Trifluorobicyclo [2.2.1] Heptoe 2

 5, 6 dichloro-1,5,6 bis (trifluoromethyl) bicyclo [2.2.1] hepto-2-ene,

 5, 5, 6 Trifluoro 6 Trifluoromethoxybicyclo [2.2.1] hept-2-ene

5, 5, 6 trifluoro-6-heptafluoropropoxybicyclo [2.2.1] hepto-2

 5— (4 fuel) bicyclo [2. 2. 1] heptoe 2

4— (Bicyclo [2. 2. 1] hepto-2-ene) -2-phenyl) sulfolbenzene, 5 -— (4 Biphenyl-carboxymethyl) bicyclo [2. 2. 1] hepto-2 5— (4-biphenyl-carbonoxyl) bicyclo [2.2.1] hepto-2-ene, 5 -— (4-biphenyl-carboxylpropyl) bicyclo [2.2.1] hepto-2

5-methyl-5- (4-biphenyl-loxymethyl) bicyclo [2.2.1] hept-2-ene,

5— (2-biphenyl-carboxymethyl) bicyclo [2.2.1] hepto-2-ene, 5 -— (2-biphenyl-loxychetyl) bicyclo [2.2.1] hepto-2 5-methyl-5- (2 biphenyl-carboxymethyl) bicyclo [2.2.1] hept-2-ene,

 5— (3 Biphenyl-Carboxyloxymethyl) bicyclo [2.2.1] Hepto-2 Nen, 5 -— (3 Biphenyl-Luoxychetyl) bicyclo [2. 2. 1] Hepto-2 Nen, 5 -— (1 Naphthylcarbo-loxymethyl) bicyclo [2. 2. 1] hepto-2-ene, 5-(1 Naphtylcarbo-loxychetyl) bicyclo [2. 2. 1] hept-o-en, [0037] 5-Methyl-5- (1 Naphthylcarbo-loxymethyl) bicyclo [2.2.1] hepto-2-ene,

 5— (2 Naphthylcarbo-loxymethyl) bicyclo [2. 2. 1] hepto-2-ene, 5 -— (2 Naphtylcarbo-loxychetyl) bicyclo [2. 2. 1] hepto-2-en, 5-methyl-5- ( 2 naphthylcarbo-loxymethyl) methylbicyclo [2.2.1] hepto-2-ene,

 5— (9 anthracylcarboxoxymethyl) bicyclo [2.2.1] hepto-2

 5— (9 Anthracel Carboxoloxychetyl) bicyclo [2.2.1] hepto-2

 5-Methyl-5- (9 Anthracel-Carboxyoxymethyl) bicyclo [2. 2. 1]

 Diagonal Alder Carobody with Acenaphthylene and Cyclopentagen

 The specific monomer b is not limited to these compounds. In addition, these compounds can be used as the specific monomer b alone or in combination of two or more.

[0038] Among these, I ^ to R ⁴ in the general formula (2) are all hydrogen atoms, or any one is a hydrocarbon group having 1 to 30 carbon atoms, and all the others are Force that is a hydrogen atom It is preferable in that it can control the water absorption of the optical film that is finally obtained. Particularly, I ^ to R ⁴ are all hydrogen atoms, or any one of the forces methyl A group, an ethyl group or a phenyl group, and all the others are hydrogen atoms, which is preferable in that a specific polymer having high strength and heat resistance can be obtained. In addition, bicyclo [2.2.1] hept— 2 and tricyclo [5. 2. 1. 0 ² · ⁶ ] Deca 1 to 8 and 5 ferbicyclo [2. 2. 1] Puto 2-en is the final optical film. It is preferable in that the effect of improving toughness is extremely remarkable.

[0039] The specific polymer obtained by copolymerizing the specific monomer a and the specific monomer b is a copolymerizable monomer other than the specific monomer a and the specific monomer b. It may be copolymerized together with it.

 Examples of other copolymerizable monomers include cycloolefin such as cyclobutene, cyclopentene, cycloheptene, cyclootaten, and dicyclopentagen. The number of carbon atoms in cycloolefin is preferably 4 to 20 forces, more preferably 5 to 12.

 In addition, specific monomers in the presence of unsaturated hydrocarbon-based polymers with olefinic unsaturated bonds in the main chain such as polybutadiene, polyisoprene, styrene butadiene copolymer, ethylene non-conjugated gen copolymer, and polynorbornene. The specific polymer obtained in such a manner that a and a specific monomer b can be polymerized as required has high impact resistance and is useful as a raw material for resin.

[0040] The intrinsic viscosity (η) of the specific polymer measured in 30 ° C black mouth form is 0.2 to

 in 5dlZg is preferred. More preferably, it is 0.3-4 dlZg, and particularly preferably 0.5-3 dlZg. If it exceeds 5 dlZg, the melt viscosity becomes too high, and the workability may deteriorate. On the other hand, if it is less than 0.2 dlZg, the film strength may decrease.

 As the molecular weight of the specific polymer, the polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is usually 8,000 to 1,000,000, preferably <ί. 10,000 to 500,000, more <preferably <ί ma 15, 000 to 100,000, special <preferably <20,000 to 100,000, and weight average molecular weight (Mw) force 20, 000 to 3,000, 000, preferred <is 30,000 to 1,000, 000, more preferred <is 40, 000 to 50 0, 000, particularly preferably 40, 000 to 300, 000 It is.

 The molecular weight distribution of the specific polymer is such that the above-mentioned MwZMn is usually from 1.5 to 10, preferably from 2 to 8, more preferably from 2.5 to 5, particularly preferably from 2.5 to 4.5. It is.

[0041] The saturated water absorption of the specific polymer at 23 ° C is preferably 0.05 to 1% by weight, more preferably It is preferably 0.1 to 0.7% by weight, particularly preferably 0.1 to 0.5% by weight. When the saturated water absorption is within this range, various optical properties such as transparency, phase difference and phase uniformity, or dimensional accuracy are maintained even under conditions such as high temperature and humidity, and adhesion with other materials is maintained. Since it is excellent in adhesion and adhesiveness, peeling does not occur during use, and compatibility with additives such as antioxidants is good, so the degree of freedom of addition is increased. If the saturated water absorption is less than 0.05% by weight, adhesion to other materials and adhesion may be poor, and peeling may easily occur during use. There may be restrictions on the formulation. On the other hand, if it exceeds 1% by weight, the optical properties and dimensional changes are likely to occur due to water absorption. The above-mentioned saturated water absorption is a value obtained by immersing in 23 ° C water for 1 week and measuring the increased weight according to ASTM D570.

[0042] The glass transition temperature (Tg) of the specific polymer is, for example, the type of the structural units a and Z or the structural unit b of the specific polymer, the adjustment of the ratio of the structural unit a to the structural unit b, or the additive. The force that can be changed as appropriate by the addition of, for example, is usually 100 to 250 ° C, preferably 110 to 200 ° C, more preferably 120 to 180 ° C. When Tg is less than 100 ° C, the heat distortion temperature is lowered, which may cause a problem in heat resistance, and the optical properties of the finally obtained film may be greatly affected by the temperature. On the other hand, Tg is 250

If the temperature exceeds ° C, the thermoplastic norbornene-based resin is more likely to be thermally deteriorated when it is heated to melt extrusion or stretching, or the optical axis is inclined in the film thickness direction of the present invention. It becomes difficult to control.

 [0043] In the specific polymer having the structural unit a and the structural unit b, the ratio (aZb) of the structural unit a to the structural unit b is preferably aZb = 95Z5 to 5Z95, more preferably 95Z5 in terms of molar ratio. ~ 60Z40. If the proportion of structural unit a is larger than the above range, the desired optical properties may not be expected due to the effect of improving toughness. Conversely, if the proportion of structural unit a is smaller than the above range, the glass transition temperature will be low, There may be a problem with heat resistance.

[0044] Further, in the specific polymer having the structural unit a and the structural unit b, it is preferable that the ratio (composition ratio) of the structural unit a and the structural unit b in the polymer has small variation in the entire molecular weight distribution range. . Specifically, the composition ratio at an arbitrary molecular weight is within ± 50%, preferably ± 3 with respect to the ratio of the specific monomer a and the specific monomer b subjected to the polymerization reaction. A more uniform optical film can be obtained by keeping the variation range within 0%, more preferably within ± 20%. Further, by keeping it in such a range, it becomes possible to obtain a more uniform retardation when stretched and oriented.

 [0045] In the following, ring-opening copolymerization of specific monomer a and, if necessary, specific monomer b or other copolymerizable monomer, or ring opening copolymerization of these monomers. The conditions for producing a specific polymer obtained by hydrogenating the obtained ring-opening copolymer after polymerization will be described.

 [0046] Ring-opening polymerization catalyst:

 The ring-opening polymerization reaction of the monomer is performed in the presence of a metathesis catalyst.

 This metathesis catalyst consists of (a) at least one compound selected from W, Mo and Re, (b) Deming periodic table group IA elements (for example, Li, Na, K, etc.), group elements (for example, Li, Na, K, etc.) Mg, Ca, etc.), group elements (eg, Zn, Cd, Hg, etc.), group elements (eg, B, A1, etc.), group IVA elements (eg, Ti, Zr), or group IVB elements (eg, Si, Sn) , Pb, etc.), and a catalyst having a combination force with at least one element selected from those having at least one elemental carbon bond or elemental hydrogen bond. In this case, an additive (c) described later may be added to increase the activity of the catalyst.

 [0047] Representative examples of W, Mo or Re compounds suitable as component (a) include WC1, MoC

 6

Examples thereof include compounds described in JP-A-1-240517 such as 1, ReOCl.

5 3

 Specific examples of the component (b) include n—C H Li, (C H) Al, (C H) A1C1, and (C H) Al.

 4 9 2 5 3 2 5 2 2 5 1. 5

CI, (C H) A1C1, methylalumoxane, LiH, etc. in JP-A-1-240517

1. 5 2 5 2

 Mention may be made of the compounds described.

 As typical examples of the component (C), alcohols, aldehydes, ketones, amines and the like can be preferably used, but the compounds described in JP-A-1-240517 can also be used. .

 [0048] The amount of the metathesis catalyst used is the component (a), the specific monomer a, and the specific monomer b.

(Hereinafter, both are referred to as “specific monomer”.) (A) Component: The specific monomer is usually in the range of 1: 500 to 1: 50,000, preferably 1: 1. , 000 to 1: 10,000. The ratio of the component (a) to the component (b) is in the range of “(a) :( b) Sl: l to l: 50, preferably 1: 2 to 1:30 in terms of metal atom ratio.

 The ratio of the component (a) to the component (c) is, as a molar ratio, “(c): (a)” is in the range of 0.005: 1 to 15: 1, preferably 0.05: 1 to 7: 1. It is.

[0049] Molecular weight regulator:

 The molecular weight of the specific polymer can be adjusted depending on the polymerization temperature, the type of catalyst, and the type of solvent. In the present invention, it is preferable to adjust the molecular weight by allowing the molecular weight regulator to coexist in the reaction system.

 Suitable molecular weight regulators include, for example, α-olefins such as ethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene. And styrene, among which 1-butene and 1-hexene are preferred.

 These molecular weight regulators can be used alone or in combination of two or more. The amount of the molecular weight regulator used is 0.005 to 0.6 mol, preferably 0.02 to 0.5 mol, per 1 mol of the specific monomer subjected to the polymerization reaction.

[0050] Solvent for ring-opening polymerization reaction:

 Examples of the solvent used in the ring-opening polymerization reaction include alkanes such as pentane, hexane, heptane, octane, nonane and decane; cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin and norbornane; Hydrocarbons such as chlorobutane, bromohexane, methylene chloride, dichloroethane, hexamethylene dibutamide, chlorobenzene, chloroform, tetrachloroethylene, etc. Saturated carboxylic acid esters such as ethyl acetate, η-butyl acetate, iso-butyl acetate, and methyl propionate; ethers such as dimethoxyethane, dibutyl ether, and tetrahydrofuran, which are used alone. Rui can be used in combination of two or more kinds. Among these, the above aromatic hydrocarbons are preferable.

The solvent is used in such an amount that the solvent: specific monomer (weight ratio) is usually 1: 1 to 10: 1, preferably 1: 1 to 5: 1. [0051] Hydrogenation:

 The ring-opening copolymer obtained by the above ring-opening polymerization can be used as a specific polymer as it is, but a hydrogenated product in which the olefinic unsaturated bond remaining in the ring-opening copolymer is hydrogenated. I prefer to do that.

[0052] This hydrogenated product has excellent thermal stability, and its characteristics are not easily deteriorated by caloric heat during film formation, stretching, or use as a product.

 In such a hydrogenated product, the hydrogenation rate with respect to the olefinic unsaturated bond is 50% or more, preferably 70% or more, more preferably 90% or more, and particularly preferably 98% or more.

 In addition, when the ring-opening copolymer used for the hydrogenation catalyst has an aromatic ring in the molecule, the aromatic ring may not be substantially hydrogenated after hydrogenation. preferable.

 [0053] The hydrogenation reaction is carried out by an ordinary method, that is, a hydrogenation catalyst is added to the solution of the ring-opening copolymer, and hydrogen gas at normal pressure to 300 atm, preferably 3 to 200 atm, is added thereto at 0 to 200 °. C, preferably by acting at 20-180 ° C.

 [0054] As the hydrogenation catalyst, those used in the usual hydrogenation reaction of olefinic compounds can be used. As this hydrogenation catalyst, a heterogeneous catalyst and a homogeneous catalyst are known. When hydrogenating a ring-opening polymer having a substituent having an aromatic ring in the molecule, it is preferable to select conditions under which the unsaturated bond of the aromatic ring is not substantially hydrogenated.

 Examples of the heterogeneous catalyst include a solid catalyst in which a noble metal such as radium, platinum, nickel, rhodium, or ruthenium is supported on a carrier such as carbon, silica, alumina, or titanium. In addition, homogeneous catalysts include nickel naphthenate, Z triethyl alminium, nickel acetyl cetate / triethyl aluminum, cobalt oxalate.

Zn-butyllithium, titanocene dichloride Z jetylaluminum monochloride, rhodium acetate, chlorotris (triphenylenophosphine) rhodium, dichlorotris (triphenylenophosphine) ruthenium, chlorohydrocarbonyltris (triphenylphosphine) ruthenium, And dichlorocarbo-lutlis (triphenylphosphine) ruthenium. The form of the catalyst may be powder or granular.

These hydrogenation catalysts, ring-opening polymer: hydrogenation catalyst (weight ratio), ι: ι χ ιο ^_6 ~

1: Used in a ratio of 2.

[0055] The specific polymer may be blended with known thermoplastic resins, thermoplastic elastomers, rubber polymers, organic fine particles, inorganic fine particles and the like as long as transparency and heat resistance are not impaired. In addition, an additive such as an acid pickling agent may be added to the specific polymer. Specific examples of antioxidants include 2,6 di-tert-butyl-4-methylphenol, 2,2'-dioxy-3,3'-di-tert-butyl-5,5'-dimethyldiphenylmethane, tetrax [methylene-13- (3,5-Di-tert-butyl 4-hydroxyphenol) propionate] methane, pentaerythrtetrakis [Methylene-3- (3,5-di-tert-butyl 4-hydroxyphenyl) propionate] 1, 1, 3 Tris (2-methyl-4-hydroxy-5-tert-butylphenol) butane, 1, 3, 5 Trimethyl 2, 4, 6 Tris (3,5 di-tert-butyl 4-hydroxybenzyl) Benzene, stearyl mono-j8 (3,5-di-tert-butyl 4-hydroxyphenol) propionate, 2,2, mono-dioxy-3,3, di-di-tert-butyl 5,5, -deethylphenol methane, 3, 9-bis [1, 1-dimethyl-2- (j8- (3- t-butyl 4- Hydroxy-5 methylphenol) propio-loxy) ethyl], 2, 4, 8, 1 0—tetraoxospiro [5.5] undecane, tris (2,4 di-tert-butylphenol) phosphite, cyclic neo Pentanetetrayl bis (2,4 tert-butylphenol) phosphite, cyclic neopentanetetrayl bis (2,6 di-tert-butyl-4-methylphenol) phosphite, 2,2-methylenebis (4,6 diol) t-Butylphenol) octyl phosphite.

[0056] Specific examples of the ultraviolet absorber include 2, 4 dihydroxybenzophenone, 2 hydroxy

 4-methoxybenzophenone and the like can be mentioned.

 The additive amount of these additives is usually 0.01 to 3 parts by weight, preferably 0.05 to 2 parts by weight per 100 parts by weight of the specific polymer.

In addition to antioxidants and ultraviolet absorbers, additives such as lubricants can be added for the purpose of improving processability. In the present invention, the optical film is obtained by molding a thermoplastic norbornene-based resin into a film or sheet by a melt extrusion method.

 Here, the extrusion equipment used in the present invention will be described.

 It is preferable to dry the coconut oil using a nitrogen circulation dryer and transport the raw materials using nitrogen. Further, it is more preferable that the upper hopper of the extruder is in a vacuum state.

 The extruder can be selected from single-screw, twin-screw, planetary, and Banbury-mixer type. However, it is common to use a single-screw extruder, and the screw shape is a full-fray type, dull type. Any of mage type, bent screw, etc. may be used, but if oxygen is mixed in the raw material melting process, it may cause gels, etc., so it is difficult to mix oxygen in the flight shape! /, Those with subflight etc. Prefer U ,.

 It is preferable to use a gear pump to transport the molten resin.

 At the time of melt extrusion molding, a mirror-polished roll is used to smoothly process the surface of the resin sheet melted into a film. As the number of mirror-polished rolls used at this time, it is preferable to use one or several rolls.

[0058] In the present invention, the obtained film or sheet is a smooth film or sheet obtained by cooling and transferring a resin sheet heated to Tg or more using two or more rolls. U, prefer to get.

[0059] The two or more rolls used at this time may be driven together or independently driven, but are preferably independently driven in order to precisely control the tilt axis of the optical axis. When the driving speed (circumferential speed) of another roll is expressed by the speed ratio F expressed by the following equation (1), F = peripheral speed of roll 1 and peripheral speed of roll 2 As speed

 0. 75 ≤F≤ 0. 99 (1)

 More preferably, 0. 77 ≤ F ≤ 0.98, and particularly preferably 0.78 ≤ F ≤ 0.96.

If F is less than 0.75, the tilt angle of the optical axis will be out of the required range, and slipping will occur between rolls, and scratches due to rubbing will easily occur on the processed film or sheet. On the other hand, if F exceeds 0.99, it becomes impossible to tilt the optical axis. [0060] Further, of the two rolls to which the Tg or higher resin sheet is transferred, the roll 1 is preferably a rubber-coated roll. If roll 1 is a metal roll, roll 1Z roll

The transfer by the gap of 2 becomes a line transfer, which partially generates a compressive stress on the sheet, which is not preferable because it tends to generate an in-plane retardation of the film. The roll of roll 1 preferably has a diameter of 100 mm or more and 300 mm or less. Rolls with a diameter exceeding 300 mm are not preferable because it is difficult to bring the T die close to the roll during processing, and the distance from the T die exit to the roll (usually referred to as the air gap) cannot be shortened. . On the other hand, when the thickness is less than 100 mm, it is difficult to precisely roll the roll, and when the surface length is increased, the roll is likely to bend and the like, which is not preferable.

 Also, a method of transferring a molten resin sheet through a base material such as a metal belt or a PET (polyethylene terephthalate) film by providing a roll for holding the base material at the bottom of the roll on the roll 1 side. Also preferred is the method.

[0061] The thickness of the metal belt to be used is not less than 0.2 mm and not more than 0.4 mm. If the thickness is less than 0.2 mm, the metal belt is easily deformed and is not preferred, but the belt exceeding 0.4 mm is used. Is not preferable because of the rigidity of the belt itself, and it is necessary to increase the diameter of the roll to be held.

 On the other hand, the thickness of the film when using a PET film is not particularly limited.

 [0062] As the shape of the roll 2 used relative to the roll 1, the surface roughness preferably having a mirror-polished surface is preferably 0.2 s or less, particularly preferably 0. Is or less. Also, the surface material of roll 2 can be peeled off by hard chrome plating, -kel plating, etc., ceramic carbide material, tungsten carbide, etc. It is preferable that the material has good properties and can be polished to a mirror surface.

[0063] Since the roll 1 and the roll 2 are covered with rubber, the roll 1 may be narrower than the thickness of the film to be manufactured. Specifically, the thickness of the film to be manufactured is t / zm) When the roll gap is dm), the metal belt used, the thickness of the substrate such as PET is 1 (m), (t 1 150) ≤d≤ (t— 20)

 It is preferable that it is in the range represented by. If the roll interval is less than (t 1−150), the in-plane retardation of the film becomes unstable, which is preferable. On the other hand, if the interval is larger than (t 20), the optical axis of the present invention is not increased. Is not preferable because it cannot be inclined.

 [0064] The pressure of the rolls 1 and 2 is preferably in the range of 0.1 to 20 MPa. More preferably, it is 0.2 to 10 MPa. 0. If the pressure is less than IMPa, the film cannot be sufficiently bonded, and the optical axis of the present invention cannot be tilted. On the other hand, if the pressure is higher than 20 MPa, the film is used in the present invention. Since the rubber-coated portion of the roll 1 is deformed, the deformation amount is preferably left as a scratch on the film.

 In the present invention, the thickness of the optical film is usually 1 to 500 / ζ πι (1,000 to 500, 00 Onm), preferably 1 to 300 / ζ πι (1,000 to 300, OOOnm). Furthermore, this is preferably 1 to 200 ^ md, 000 to 200, 000), and most preferably 10 to 150 (10,000 to 150, OOO nm). When this thickness is less than Lm, it becomes difficult to handle the optical film substantially. On the other hand, if this thickness exceeds 500 / z m, when the pre-processed film is wound up in a roll, it will be a so-called “Kakiguse”! , Handling in post-processing may be difficult.

 The thickness distribution of the optical film is usually within ± 10%, preferably within ± 5%, more preferably within ± 1%, and particularly preferably within ± 0.5% with respect to the average value. Further, the variation in thickness per cm is usually 1% or less, preferably 0.1% or less, more preferably 0.01% or less, and particularly preferably 0.005% or less. By controlling the thickness distribution of the optical film within the above range, it is possible to prevent the occurrence of uneven retardation and uneven alignment of the optical axis when the stretching process is performed.

 [0066] In order to produce the optical film of the present invention, stretching may optionally be performed. Specifically, a known uniaxial stretching method or biaxial stretching method can be used. In other words, the horizontal uniaxial stretching method using the tenter method, the compression stretching method between rolls, the vertical uniaxial stretching method using two sets of rolls with different circumferences, or the biaxial stretching method combining horizontal uniaxial and vertical uniaxial. A stretching method can be used.

In the case of the uniaxial stretching method, the stretching speed is usually 1 to 5,000% Z, preferably 50 to It is 1,000% Z minutes, more preferably 100 to 1,000% Z minutes, and particularly preferably 100 to 500% Z minutes.

 In the case of the biaxial stretching method, stretching may be performed in two directions at the same time, or may be performed in a direction different from the initial stretching direction after uniaxial stretching. At this time, the intersecting angle of the two stretching axes for controlling the shape of the refractive index ellipsoid of the stretched film is not particularly limited because it is determined by desired characteristics, but is usually 120 to 60 degrees. It is a range. In addition, the stretching speed may be the same or different in each stretching direction, and is usually 1 to 5,000% Z minutes, preferably 50 to: L, 000% Z minutes, The amount is preferably 100 to 1,000% Z, and particularly preferably 100 to 500% Z.

 [0067] The treatment temperature in the stretch orientation treatment is usually Tg—15 ° C to Tg + 10 ° C, preferably Tg ± 10 ° C, more preferably, based on the glass transition temperature Tg of the thermoplastic norbornene-based resin. Is in the range of Tg—10 ° C to Tg + 5 ° C. By setting the processing temperature within the above range, the inclination of the optical axis in the thickness direction of the film formed by melt extrusion can be well maintained, and the occurrence of uneven retardation can be suppressed. This is preferable because it makes it easier to control the refractive index ellipsoid.

 The draw ratio is not particularly limited since it is determined by desired properties, but is usually 1.0 to 10 times, preferably 1.03 to 5 times, and more preferably 1.03 to 3 times. When the draw ratio exceeds 10 times, it may be difficult to control the phase difference.

 [0068] The stretched film may be cooled as it is, but it is kept in a temperature atmosphere of Tg—20 ° C. to Tg for at least 10 seconds, preferably 30 seconds to 60 minutes, more preferably 1 minute to 60 minutes. It is preferable to hold and heat set. As a result, a stable optical film can be obtained with little change over time in the retardation of transmitted light.

 [0069] The dimensional shrinkage ratio due to heating of the optical film of the present invention is usually 1% or less, preferably 0.5% or less, more preferably 1%, when a calorie heat at 100 ° C is performed for 500 hours. It is as follows.

In order to keep the dimensional shrinkage within the above range, for example, a specific monomer a, a specific monomer b, or another copolymerizable monomer, which is a raw material of thermoplastic norbornene-based resin, is selected. In addition, it can be controlled by the melt extrusion method and the stretching method that was performed in some cases. Is possible.

 [0070] The film stretched as described above has a force that gives a phase difference to the transmitted light due to the orientation of the molecules by stretching. This phase difference is caused by the thermoplastic norbornene-based film used as a raw material. It can be controlled by adjusting the type of fat, the melt extrusion method, for example, the stretching method such as stretching ratio and stretching temperature, or the thickness of the optical film.

 For example, with regard to stretching, as for the stretching ratio, even if the film has the same thickness before stretching, the stretching ratio tends to increase and the absolute value of the retardation of transmitted light tends to increase as the film increases. By changing the draw ratio, a film that imparts a desired phase difference to the transmitted light can be obtained. As for the thickness of the optical film before stretching, the absolute value of the phase difference given to transmitted light tends to increase as the thickness of the film before stretching increases even if the stretching ratio is the same. By changing the thickness of the film, it is possible to obtain an optical film that imparts a desired retardation to transmitted light. As for the stretching temperature, the lower the stretching temperature, the larger the absolute value of the transmitted light phase difference. Therefore, the phase difference that gives the desired phase difference to the transmitted light by changing the stretching temperature. A film can be obtained.

 [0071] Further, in order to adjust the thickness of the optical film after stretching, it can be controlled by adjusting the thickness of the film before processing, the stretching ratio, and the like. Specifically, for example, the thickness of the retardation film can be reduced by reducing the thickness of the optical film before drawing or increasing the draw ratio.

 In such an optical film of the present invention, the optical axis in the film thickness direction is inclined with respect to the film normal direction. Here, the optical axis in the film thickness direction means the refractive index Nz that indicates the film thickness direction exclusively when the refractive indexes of the apparent refractive index ellipsoid of the optical film of the present invention are Nx, Ny, and Nz. Represents the axial direction.

 [Nx and Ny are the refractive indices in the in-plane direction of the film, Nz is the refractive index in the film thickness direction, and the angle formed by the axes of Nx, Ny, and Nz is 90 degrees. ]

Here, the optical axis in the film thickness direction is usually 3 to 40 degrees, preferably 5 to 35 degrees, and more preferably 10 to 30 degrees with respect to the film normal direction. The optical axis in the film thickness direction Outside the above range, for example, the optical compensation effect may be insufficient for a TN mode liquid crystal panel. The optical axis in the film thickness direction is appropriately adjusted according to the liquid crystal panel used. To adjust the optical axis in the film thickness direction, when transferring the film with a mirror roll, etc., use heated rolls from both sides of the film to transfer and cool the film while applying pressure. It is preferable. In particular, when transferring a film, it is a preferable production method to perform cooling transfer from both sides using a mirror roll on one side and a rubber roll on the other side and using a metal belt between them. It is more preferable to change the feeding speed of the mirror roll and the metal belt at the time of transfer. Furthermore, the difference in speed between the mirror roll and the metal belt is particularly preferably 0.5 mZmin or less. The inclination of the optical axis in the film thickness direction described above can be easily achieved by using a phase difference (birefringence) measuring device, such as KOBRA-21ADH manufactured by Oji Scientific Instruments Co., Ltd. Can be measured. More specifically, the phase difference (birefringence) is measured when the optical film transmits light perpendicular to the film and when tilted from the normal direction of the film, for example, 10 degrees or 20 degrees. You can ask for it.

 [0073] The retardation (RO) in the film plane of the optical film of the present invention is usually 5 to 30 Onm, preferably 40 to 250 nm, and more preferably 90 to 250 nm. If the Kojiki phase difference (RO) is out of the above range, the optical compensation effect may not be obtained. This phase difference (R 0) is appropriately adjusted according to the liquid crystal panel used. In order to adjust the phase difference (RO) in the film plane, it is desirable to cool the film by transfer with a double-sided force in order to quickly cool the film to a temperature below the glass transition temperature. In the processing equipment such as the cooling roll and the metal belt at this time, it is desirable that there is no film thickness unevenness or temperature unevenness.

[0074] In such an optical film, the number of the Kino bright spot converted per lm ² on the film surface is usually 5 or less, preferably 3 or less, more preferably 0 or 1 It is.

Here, the “bright spot” is a partial light leakage that is observed with the naked eye when an optical film is sandwiched between cross-colled polarizing plates, and usually has an outer diameter of 1 m or more ( If it is circular, measure its diameter, and if it has other shapes, measure its length in the longitudinal direction). The Of course, depending on the required performance, a smaller spot may be measured as a bright spot.

 In addition, bright luminescent spots are considered to be caused by partial unevenness of the phase difference in a minute region. In other words, if foreign matter or bubbles are present in the optical film before being stretched, even if the size is such that they cannot be confirmed with the naked eye, stress is applied to the portion where foreign matter or bubbles are present when stretched. Concentrated, the phase difference of the stress concentrated part may be different from the phase difference of the peripheral part, and it is considered that light leaks due to the difference of the phase difference.

In order to reduce the number of “bright spots” to 5 or less, it is preferable that the raw materials used do not contain any contaminants that may cause bright spots such as gel. In particular, the gel in the resin has difficulty in producing a sufficiently flat surface by the transfer roll, and it is not preferable that such a material is contained in a large amount in the raw material. In order to reduce the number of bright spots, the gel can be removed or reduced by using an appropriate combination of polymer filters and the like. In the optical film of the present invention, the number of foreign substances when converted to lm ² on the film surface is preferably 5 or less, more preferably 3 or less, and particularly preferably 0 or 1.

 The “foreign matter” referred to here is a substance that substantially impedes the transmission of light when light is transmitted through the optical film. When such a foreign substance is present in the optical film, the intensity of transmitted light is affected, and when used in a liquid crystal display element or the like, there is a risk of pixel omission or deterioration of characteristics.

 The size of the foreign matter to be measured is usually required to have an outer diameter of 1 μm or more (the diameter is circular if it is circular, or the length in the longitudinal direction if it is other shape). Depending on the performance, a smaller object may be measured as a foreign object.

To reduce the number of foreign materials to 5 or less, it is the same as in the case of the bright spot described above, but it is desirable to reduce foreign materials in the raw material. In order to reduce the foreign matter in the raw material, it is preferable to narrow the eyes with a polymer filter or the like. Since foreign objects with a diameter of 20 m or more are easily visible, using a filter with a mesh opening smaller than 10 m can remove foreign objects that are visible. [0076] The optical film of the present invention can be used alone or in a state in which two or more different types of films are laminated, and can be bonded to a polarizing film as a protective film. Such a protective film is a polarizing film. A laminate having a structure of being bonded to each of both surfaces can be suitably used as a polarizing plate.

 Specific examples of the structure of the laminate that can be used as the polarizing plate are as follows, for example.

 (1) A laminate obtained by bonding a triacetyl cellulose (hereinafter abbreviated as “TAC”) film on one surface of a polarizing film and bonding the optical film of the present invention on the other surface of the polarizing film.

 (2) A laminate obtained by bonding the optical film of the present invention to both surfaces of a polarizing film

 [0077] When the optical film of the present invention is laminated on a substrate such as another film, sheet or glass, an adhesive or an adhesive can be used. Specific examples of adhesives and adhesives that are highly transparent are natural rubber, synthetic rubber, butyl acetate, Z salt butyl copolymer, polyvinyl ether, and acrylic. Curable adhesives, such as adhesives such as resin-based resins and modified polyolefin-based resins, and curing resins such as isocyanate group-containing compounds added to the above resins having functional groups such as hydroxyl groups and amino groups. Examples include dry laminating adhesives, synthetic rubber adhesives, epoxy adhesives, and water-based adhesives based on polybutyl alcohol.

 In addition, the optical film of the present invention can be previously laminated with a pressure-sensitive adhesive layer or an adhesive layer in order to improve the workability of lamination with other films, sheets, substrates and the like. In the case of lamination, the above-mentioned pressure-sensitive adhesive or adhesive can be used as the pressure-sensitive adhesive or adhesive.

 [0078] In the optical film of the present invention, a transparent conductive layer can be laminated on at least one surface thereof.

 As a material for forming the transparent conductive layer, metals such as Sn, In, Ti, Pb, Au, Pt, and Ag or their oxides can be used.

The transparent conductive layer made of a metal oxide can be formed by directly depositing a metal oxide on the substrate, but it is deposited on the substrate in the form of a simple metal or a lower oxide to form a film. After that, heat oxidation treatment, anodization treatment or liquid phase oxidation treatment It can be formed by performing acidification treatment such as the above to make it transparent. The transparent conductive layer may be formed by adhering other sheets or films having a transparent conductive layer to an optical film, a plasma polymerization method, a sputtering method, a vacuum deposition method, a plating, an ion plating method. It may be formed directly on an optical film by the method, spray method, electrolytic deposition method, etc.

 The thickness of such a transparent conductive layer is determined according to the desired characteristics, and is not particularly limited. Usually, it is 10 to: LO, OOOA, preferably 50 to 5, οοοΑ. is there.

[0079] When the transparent conductive layer is directly formed on the optical film of the present invention, an adhesive layer or an anchor coat layer may be formed between the optical film and the transparent conductive layer as necessary. .

 Here, examples of the material constituting the adhesive layer include heat-resistant resins such as epoxy resin, polyimide, polybutadiene, phenol resin, polyether ether ketone, and the like. Examples thereof include those cured by a known curing method, for example, UV curing or heat curing, using a component containing a so-called acrylic prepolymer such as rate, urethane diatalylate, or polyesterdiatalate.

 [0080] In addition, an optical film (hereinafter, also referred to as "optical composite film") formed by laminating a transparent conductive layer has a polyvinyl chloride film to reduce oxygen and water vapor permeability, if necessary. A gas- noble material such as redene chloride or polybulualcohol can be laminated on at least one surface of the optical composite film.

Further, for the purpose of improving the scratch resistance and heat resistance of the optical composite film, a hard coat layer may be laminated directly on the optical composite film or on the gas noble layer. Here, as the hard coat agent, an organic hard coat material such as an organic silicone resin, a melamine resin, an epoxy resin, an acrylic resin, or an inorganic hard coat material such as a silicon dioxide resin is used. be able to. Of these, hard coat materials such as organic silicone resins and acrylic resins are preferable. As the organosilicone resin, those having various functional groups are used. Those having an epoxy group are preferred. [0081] In the optical film of the present invention, an antireflection layer can be laminated on at least one surface thereof.

 As a method for forming the antireflection layer, for example, a commonly used inorganic type made of a metal oxide such as silicon, titanium, tantalum, zirconium, etc., for example, polyvinylidene fluoride, hexaneful, etc. An organic anti-reflection film made of fluorine-containing compounds such as (propylene) and tetrafluoroethylene (co) polymers and fluorine-containing (meth) acrylate (co) polymers is about 0.01 to 10 m. The film can be formed by a method such as sputtering, vapor deposition, coating, and dipping. The thickness of the antireflection layer is usually from 0.01 to 50 m, preferably from 0.1 to 30 m, more preferably from 0.5 to 20 m. If it is less than 0.01 μm, the antireflection effect cannot be exhibited, and if it exceeds 50 μm, unevenness in the thickness of the coating film tends to occur and the appearance is deteriorated.

 [0082] Further, the optical film in which the antireflection layer is laminated may be laminated with a known hard coat layer or antifouling layer, or may be laminated with the transparent conductive layer. Furthermore, as an optical film in which an antireflection layer is laminated, an optical film having a light diffusion function can be used.

 As described above, when an optical film having a plurality of functions and having an antireflection layer laminated thereon is used for, for example, a liquid crystal display element, the antireflection film is a retardation plate, a light diffusion film, a polarizing film protective film. Alternatively, some functions of the electrode substrate (transparent conductive layer) are shared, and the number of parts can be reduced as compared with the conventional case.

 [0083] The polarizing plate of the present invention has a configuration in which a protective film is laminated on each of both surfaces of a polarizing film, and as described above,

 (1) A laminate in which a TAC film is bonded to one surface of the polarizing film and the optical film of the present invention is bonded to the other surface of the polarizing film.

 (2) A laminate obtained by bonding the optical film of the present invention to both surfaces of a polarizing film

 These two types of polarizing plates are included.

According to the polarizing plate having such a configuration, since the protective film can have a retardation function as well as a protective function, there is an advantage that it is not necessary to bond a retardation plate to the polarizing plate. For example, thin film and high performance products such as liquid crystal display devices Can be achieved.

 Example

 [0084] In the following, the ability to explain specific examples of the present invention The present invention is not limited to these examples. In the following, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified.

 In the following examples, glass transition temperature, saturated water absorption, total light transmittance, in-plane retardation of transmitted light, optical axis tilt angle in the film thickness direction, transmittance and polarization of polarizing plate, reflectance The number of bright spots and scratch resistance were measured by the following methods.

[0085] [Glass transition temperature (Tg)]

 Using a differential scanning calorimeter (DSC) manufactured by Seiko Instruments Inc., the glass transition temperature was measured in a nitrogen atmosphere at a temperature rising rate of 20 ° CZ.

 [Saturated water absorption]

 In accordance with ASTM D570, a sample was immersed in water at 23 ° C for 1 week, and the change in the weight of the sample before and after immersion was measured to determine the value saturation water absorption.

 [Total light transmittance]

 The total light transmittance was measured using a haze meter “HM-150” manufactured by Murakami Color Research Laboratory.

 [In-plane retardation of transmitted light (RO)]

 Using “KOBRA-21ADH” manufactured by Oji Scientific Instruments, the in-plane retardation (RO) when light was incident on the film perpendicularly was measured at a wavelength of 590 nm.

 [Optical axis tilt angle in the film thickness direction]

 Using the “KOBRA-21ADH” manufactured by Oji Scientific Instruments Co., Ltd., the film width direction (TD direction) was measured as the tilt axis, and the phase difference at a tilt angle of 50 degrees [hereinafter referred to as R (50)] , And tilt angle-The phase difference at 50 degrees [hereinafter R (-50) t, and] and the tilt angle of the optical axis [hereinafter referred to as j8] were measured. The measurement wavelength was 590 nm.

 [Transmissivity and degree of polarization of polarizing plate]

Using the “KOBRA-21ADH” manufactured by Oji Scientific Instruments, the transmittance and polarization of the polarizing plate were measured. The measurement wavelength was 550 nm. [Reflectance]

 The reflectance at an incident angle of 5 degrees was measured using a spectrophotometer U-3310 manufactured by Hitachi, Ltd.

[Number of bright spots]

A sample was sandwiched between polarizing plates in a cross-col state on a light source with a luminance of l, 000 cdZm ² and a partial light leak with an outer diameter of 1 μm or more, which was confirmed with the naked eye, was measured as a bright spot. .

 Wounded]

 In accordance with JIS K5400, scratch resistance was confirmed by performing a pencil hardness test.

<Synthesis example 1>

A reaction vessel was replaced with nitrogen, 8-methyl as the specific monomer a - 8 carboxymethyl Te Torashikuro ^{[4. 4. 0. I 2 '5} I 7.' 10] - and 3-dodecene 225 parts, certain single Bisquish [2.2.1] heptoe-2-ene 25 parts, molecular weight regulator 1 part hexene 27 parts and toluene 750 parts solvent as the monomer b, and the solution was brought to 60 ° C Heated. Next, 0.62 parts of a toluene solution containing 1.5 mol / l of triethyl aluminum as a polymerization catalyst, and tungsten hexachloride (t-butanol: methanol modified with t-butanol and methanol) were added to the solution in the reaction vessel. : Tungsten = 0.35 mol: 0.3 mol: 1 mol) Concentration 0.05 mol Z1 in toluene solution 3. Add 7 parts and stir this system at 80 ° C for 3 hours. Thus, a ring-opening copolymerization reaction was performed to obtain a ring-opening copolymer solution.

 The polymerization conversion rate in this polymerization reaction was 97%, and the intrinsic viscosity (7?) Of the ring-opening copolymer composing the obtained ring-opening copolymer solution in 30 ° C chloroform was determined. As measured

 in

It was 0.51 dl / g.

 The autoclave was charged with 4,000 parts of the ring-opening polymer solution thus obtained, and 0.48 part of RuHCl (CO) [P (CH 3)] was added to the ring-opening polymer solution to obtain hydrogen. Gas pressure 100

 6 5 3 3

Hydrogenation reaction was performed by heating and stirring for 3 hours under the conditions of kg / cm ² and reaction temperature of 165 ° C. After cooling the obtained reaction solution (hydrogenated polymer solution), the hydrogen gas was released. . This reaction solution is poured into a large amount of methanol, and the coagulum is separated and recovered by drying. A hydrogenated polymer (hereinafter, this ring-opening copolymer is referred to as rosin (a-1)) was obtained.

The hydrogenation rate of the thus obtained rosin (a-1) was measured using ¹ H-NMR and found to be 99.9%.

[0087] Further, with respect to the resin (a-1), the number average molecular weight (Mn) and the weight average molecular weight (Mw) in terms of polystyrene were measured by gel permeation chromatography (GPC, solvent: tetrahydrofuran). However, the number average molecular weight (Mn) was 20,800, the weight average molecular weight (Mw) was 62,000, and the molecular weight distribution (MwZMn) was 3.00.

The glass transition temperature (Tg) of rosin (a-1) was 130 ° C, and the saturated water absorption rate at 23 ° C was 0.3%. The SP value of rosin (a-1) was measured and found to be 19 (MPa ^1/2 ), and the intrinsic viscosity () measured at 30 ° C in black mouth form was 0.51 dlZg. It was.

 [0088] <Synthesis Example 2>

As specific monomer a, 8-methyl-8-methoxycarborutetracyclo [4. 4. 0. I ² ' ^5. I ⁷ ' ^{1 (>} ] — 237 parts of 3-dodecene and as specific monomer b 5 — Hydrogenated polymer (hereinafter referred to as “resin”) in the same manner as in Synthesis Example 1 except that 13 parts of (4-biphenyl-carboxymethyl) bicyclo [2.2.1] hept-2-ene was used. (b-1) ”).

 The hydrogenation rate of the obtained rosin (b-1) was 99.9% as measured by 400 MHz Η-NMR ^ vector, and the aromatic ring was not substantially hydrogenated. Was confirmed.

 The number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene were measured for gel (b-1) by gel permeation chromatography (GPC, solvent: tetrahydrofuran). The average molecular weight (Mn) was 19,000, the weight average molecular weight (Mw) was 57,000, and the molecular weight distribution (MwZMn) was 3.98.

 The glass transition temperature (Tg) of rosin (b-1) was 150 ° C, and the saturated water absorption rate at 23 ° C was 0.3%. The intrinsic viscosity () of rosin (b-1) measured in black mouth form at 30 ° C was 0.47 dlZg.

 [0089] <Preparation Example 1>

A reaction vessel was charged with 250 parts of distilled water. The reaction vessel was charged with 90 parts of butyl acrylate, 8 parts of 2-hydroxyethyl methacrylate, 2 parts of divinylbenzene, and potassium oleate. After adding 0.1 part of hum, the system is added to polytetrafluoroethylene (Teflon: registered trademark).

The mixture was agitated with a stirring blade made of) and dispersed. Thereafter, the inside of the reaction vessel was purged with nitrogen, and then the temperature of the system was raised to 50 ° C., and 0.2 part of potassium persulfate was added to initiate polymerization. After 2 hours from the start of polymerization, 0.1 parts of potassium persulfate was further added to the polymerization reaction system, and then this system was heated to 80 ° C., and the polymerization reaction was continued for 1 hour. A coalescence dispersion was obtained.

 Next, by using an evaporator, the aqueous dispersion (adhesive having a polar group) having an aqueous dispersion strength of an acrylic ester polymer is obtained by concentrating the polymer dispersion until the solid content becomes 70%. Obtained.

 The thus obtained water-based pressure-sensitive adhesive (hereinafter referred to as “water-based pressure-sensitive adhesive A”) is subjected to gel permeation chromatography (GPC, solvent: tetrahydrofuran) by gel permeation chromatography (GPC). When the number average molecular weight (Mn) and the weight average molecular weight (Mw) in terms of polystyrene were measured, the number average molecular weight (Mn) was 69,000, and the weight average molecular weight (Mw) was 135,000.

 In addition, for the water-based adhesive A, the intrinsic viscosity () was measured in a black mouth form at 30 ° C. and found to be 1.2 dlZg.

[Example 1]

Coffin (a-1) was dissolved in toluene to a concentration of 30%. The solution viscosity at room temperature of the obtained solution was 30, OOOmPa's. To this solution, pentaerythrityltetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenol) propionate] was added as an anti-oxidation agent to 0.3 parts of 100 parts of rosin (a-1). Using a metal fiber sintered filter made by Nippon Seisen with a nominal aperture of 10 m, the solution flow rate was adjusted so that the differential pressure was kept within 2 MPa. And filtered with a twin screw extruder (Toshiba Machine Co., Ltd .; TEM-48), using a gear pump to extrude downstream using a 3-stage vent. Using a metal fiber sintered filter with nominal filtration accuracy (metal powder sintered type: opening ratio 50%), melt filtration is performed so that the differential pressure is within 3.5 MPa, and a coat hanger type T-die (650mm width), T die outlet clearance is 0.5mm and discharge at 280 ° C is 32kgZ Fixed to hr, membrane Extruded.

 Next, the extruded film was sandwiched between a 300 mm diameter mirror surface roll having a surface roughness of 0.1 S and a metal belt having a thickness of 0.3 mm, and the surface of the film was transferred to a glossy surface. The metal belt (width 700 mm) is held by a rubber-coated roll (the diameter of the roll to be held is 150 mm) and a cooling roll (roll diameter 150 mm), and a commercially available sleeve-type transfer roll (manufactured by Chiba Kikai Kogyo) is used. And transcribed. The distance between rolls when transferring was 0.35 mm, and the transfer pressure was a linear pressure of 25 kgfZcm.

 At this time, the peripheral speed of the outer periphery of the mirror roll was set to 8.8 mZmin. The peripheral speed of the rubber-coated roll was controlled at 8.5 mZmin. At this time, the temperature of the mirror surface roll was set to 125 ° C. using a oil temperature controller, and the temperature of the rubber coating roll was set to 115 ° C.

 After that, the resin film peeled from the mirror roll was pasted to the protective film, and the resin film with a thickness of 100 m (excluding the protective film thickness) (hereinafter also referred to as “resin film (a-2)”) Formed.

 As a result of peeling off the protective film from the resin film (a-2) and measuring the properties as an optical film, it was confirmed that the optical axis in the thickness direction was inclined. Table 1 shows the optical characteristics measurement results. In addition, the total light transmittance of the obtained resin film (a-2) was 93%. Furthermore, the number of bright spots of the resin film (a-2) was 0 to 1.

[0091] [Example 2]

 In Example 1, the thickness was 100 m (the thickness of the protective film was the same as in Example 1) except that the resin (b-1) was used instead of the resin (a-1). A resin film (hereinafter, also referred to as “resin film (b-2)”).

 As a result of peeling off the protective film from the resin film (b-2) and measuring the properties as an optical film, it was confirmed that the optical axis in the thickness direction was inclined. Table 1 shows the optical characteristics measurement results. Further, the total light transmittance of the obtained resin film (b-2) was 92%. In addition, the number of bright spots in the resin film (b-2) was 0-1.

[0092] [Example 3]

Coffin (a-1) was dissolved in toluene to a concentration of 30%. The solution viscosity at room temperature of the obtained solution was 30, OOOmPa's. To this solution, Add 0.3 parts of erythrityltetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenol) propionate] to 100 parts of rosin (a-1) and add the resulting solution to Japan. A metal fiber sintered filter with a pore diameter of 5 m was used to filter the solution while controlling the flow rate of the solution so that the differential pressure was within 0.4 MPa, and then a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.). ; TEM-48), a metal fiber sintered filter made by Nippon Seisen with a nominal opening of 10 m, which is extruded downstream using a gear pump while degassing toluene with a three-stage vent. Using a coat hanger type T die (650 mm wide), the gap at the exit of the T die was 0.5 mm and extruded into a film at 280 ° C.

 The extruded film was sandwiched between a mirror roll having a surface roughness of 0.1 S and a metal belt having a thickness of 0.3 mm, and the film surface was transferred to a glossy surface. The metal belt (width 700 mm) was held by a rubber-covered roll and a cooling roll, and was transferred using a commercially available sleeve-type transfer roll (manufactured by Chiba Machine Industry). The distance between the rolls when transferring was 0. Omm, and the transfer pressure was a pressure of 0.3 MPa.

 At this time, the peripheral speed of the outer periphery of the mirror roll was set to 5.90 mZmin. In addition, the peripheral speed of the rubber-coated nozzle was controlled at 6.15 m / min. At this time, the temperature of the mirror surface roll was set to 120 ° C. using an oil temperature controller, and the temperature of the rubber coating roll was set to 115 ° C.

 After that, the resin film peeled off from the mirror roll was pasted to the protective film, and the resin film with a thickness of 150 m (excluding the protective film thickness) (hereinafter also referred to as “Oxidized film (a-3)”) Formed.

 As a result of peeling off the protective film from the resin film (a-3) and measuring the properties as an optical film, it was confirmed that the optical axis in the thickness direction was inclined. Table 1 shows the optical characteristics measurement results. In addition, the total light transmittance of the obtained resin film (a-3) was 93%. Furthermore, the number of bright spots of the resin film (a-3) was 0 to 1.

[Example 4]

 In Example 3, the thickness was 180 m in the same manner as in Example 1 except that the resin (b-1) was used instead of the resin (a-1) and the discharge was changed to 57 kg Zhr. A resin film (hereinafter, also referred to as “resin film (b-3)”) was obtained (excluding the protective film thickness).

Remove the protective film from the resin film (b-3) and measure the characteristics as an optical film. As a result, it was confirmed that the optical axis in the thickness direction was inclined. Table of optical characteristics measurement results

Shown in 1. In addition, the total light transmittance of the obtained resin film (b-3) was 92%. Furthermore, the number of bright spots in the resin film (b-3) was 0 to 1.

[0094] [Example 5]

 The protective film was peeled from the resin film (a-2) obtained in Example 1, and heated to 125 ° C (Tg-5 ° C) in a tenter, and the film surface was stretched at a rate of 300% Z. Stretched 1.04 times in the longitudinal direction inward. After that, it is cooled while maintaining this state for 1 minute in an atmosphere of 110 ° C (Tg—20 ° C), further cooled at room temperature, and taken out from the tenter to obtain a phase difference film (hereinafter referred to as “position”). A phase difference film (a-4) ”was also obtained.

 As a result of measuring the properties of the retardation film (a-4) as an optical film, it was confirmed that the optical axis in the thickness direction was inclined. Table 1 shows the optical characteristics measurement results. In addition, the total light transmittance of the obtained retardation film (a-4) was 93%. Further, the number of bright spots of the retardation film (a-4) was 0 to 1.

[0095] [Example 6]

 The protective film was peeled from the resin film (b-2) obtained in Example 2, and heated to 145 ° C (Tg-5 ° C) in a tenter, and the film surface was stretched at a rate of 300% Z. Stretched 1.08 times in the longitudinal direction of the inward direction. After that, it is cooled while maintaining this state for 1 minute in an atmosphere of 130 ° C (Tg—20 ° C), further cooled at room temperature, and taken out of the tenter to obtain a phase difference film (hereinafter referred to as “position”). A phase difference film (b-4) "was also obtained.

 As a result of measuring the properties of the retardation film (b-4) as an optical film, it was confirmed that the optical axis in the thickness direction was inclined. Table 1 shows the optical characteristics measurement results.

 Further, the total light transmittance of the obtained retardation film (b-4) was 93% or more. Furthermore, the number of bright spots in the retardation film (b-4) was 0 to 1.

[0096] [Example 7]

The protective film was peeled from the resin film (a-2) obtained in Example 1, heated to 130 ° C (Tg) in a tenter, and stretched in the in-plane direction at a stretching rate of 300% Z. Stretched 1.25 times in the direction. After that, keep this state for 1 minute in an atmosphere of 110 ° C (Tg—20 ° C). Cool it down at room temperature and take it out from the tenter. (Hereinafter also referred to as “retardation film (a-5)”).

 As a result of measuring the properties of the retardation film (a-5) as an optical film, it was confirmed that the optical axis in the thickness direction was inclined. Table 1 shows the optical characteristics measurement results. Further, the total retardation of the obtained retardation film (a-5) was 93%. Further, the number of bright spots of the retardation film (a-5) was 0 to 1.

[0097] [Example 8]

 Polybur alcohol (hereinafter abbreviated as “PVA”) was spread in a dyeing bath at a temperature of 30 ° C. consisting of an aqueous solution having an iodine concentration of 0.03% and a potassium iodide concentration of 0.5%. A pre-stretching process was performed at a stretching ratio of 3 times, and after that, in a crosslinking bath consisting of an aqueous solution having a boric acid concentration of 5% and a potassium iodide concentration of 8%, the stretching ratio was 2 times. A polarizing film (hereinafter also referred to as “polarizer (1)”) was obtained by performing a post-stretching process and a drying process, and then using the aqueous adhesive A on one surface of the polarizer (1). Apply a resin film (a-2) to the other side of the polarizer (1). PVA adhesive (manufactured by Wako Pure Chemical Industries, Ltd. A 7% by weight aqueous solution (the same shall apply hereinafter) and attach a TAC film to the top surface of the TAC film using water-based adhesive A. By kicking attaching a beam (a- 4), a polarizing plate (hereinafter also referred to as "polarizing plate (a- 8)") was obtained.

 The polarizing plate (a-8) obtained had a transmittance of 44.0%, a degree of polarization of 99.9%, and the number of bright spots was 0-1.

 When the pencil hardness test was conducted on the polarizing plate (a-8), it was confirmed that the hardness was 2H and it had good scratch resistance.

[0098] Further, apart from the polarizing plate (a-8), the resin film (a-2) was attached to one surface of the polarizer (1) using the water-based adhesive A, and the polarizer (1 ) A phase difference film (a 4) is affixed to the other side using water-based adhesive A, and then the nitride film is applied to the upper surface of the phase difference film (a 4) under a vacuum of 1 X 10 "4Τοπ :. A first vapor deposition film having a thickness of 80 nm is formed by vapor deposition, and further, a second vapor deposition film having a thickness of 20 nm by vapor deposition of terbium-iron-cobalt alloy (TbFeCo), and a third vapor deposition film having a thickness of 30 nm by vapor deposition of silicon nitride. And aluminum on the outer layer A fourth deposited film having a thickness of 50 nm was formed in this order by vapor deposition of Al (Al), thereby giving an antireflection function derived from the antireflection layer formed by laminating a total of four deposited films. Next, on the antireflection layer, 25 parts of methyltrimethoxysilane and methanol-dispersed colloidal silica (solid content concentration 30%, manufactured by Nissan Chemical Industries, Ltd.) were placed in a reactor equipped with a reflux condenser and a stirrer. 10 parts of methanol sol) and 6 parts of tap water were added, the system was heated to 70 ° C and reacted for 2 hours, and then the coating composition obtained by adding 38 parts of i-propyl alcohol, Applying with an air spray gun and heating at 140 ° C for 60 minutes to form a cured film with a thickness of 10 m, a polarizing plate (hereinafter also referred to as “polarizing plate (a 9)”) is obtained. It was.

 The obtained polarizing plate (a-9) had a transmittance of 47.0%, a degree of polarization of 99.9%, and a number of bright spots of 0 to 1.

 In addition, when the reflectance was measured by injecting light having a wavelength in the range of 400 to 700 nm from the antireflection layer side to the polarizing plate (a-9), the reflectance for light of any wavelength was less than 1%. It was confirmed that it had a good antireflection function.

 Furthermore, when a pencil hardness test was conducted, it was confirmed that the hardness was 2H and it had good scratch resistance.

[0099] [Example 9]

 On one side of the polarizer (1) obtained in the same manner as in Example 7, the water-based adhesive A was used to attach the resin film (b-2), and on the other side of the polarizer (1), the PVA series A TAC film is attached using an adhesive, and a retardation film (b-4) is attached to the upper surface of the TAC film using an aqueous adhesive A. 7) ”.

 The polarizing plate (b-7) obtained had a transmittance of 44.0%, a polarization degree of 99.9%, and the number of bright spots was 0-1.

 When the pencil hardness test was conducted on the polarizing plate (b-7), it was confirmed that the hardness was 2H and it had good scratch resistance.

[0100] Further, apart from the polarizing plate (b-7), the resin film (b-2) was attached to one surface of the polarizer (1) using the water-based adhesive A, and the polarizer (1 ) Adhere the phase difference film (b-4) to the other side using water-based adhesive A, and then apply pressure IX 10 on the upper surface of the phase difference film (b-4). ^_4 T _OTr is vacuum-deposited to form a first deposited film with a thickness of 80 nm, and terbium-iron-cobalt alloy (TbFeCo) is deposited to form a second deposited film with a thickness of 20 nm A total of four deposited films are laminated by depositing aluminum (A1) on the third deposited film of 30 nm thickness and the outer layer to form a fourth deposited film of 50 nm thickness in this order. An antireflection function derived from the antireflection layer was added. Next, on the antireflection layer, 25 parts of methyltrimethoxysilane and methanol-dispersed colloidal silica (solid content concentration 30%, manufactured by Nissan Chemical Industries, Ltd.) were placed in a reactor equipped with a reflux condenser and a stirrer. 10 parts of methanol sol) and 6 parts of tap water were added, the system was heated to 70 ° C and reacted for 2 hours, and then the coating composition obtained by adding 38 parts of i-propyl alcohol, Applying with an air spray gun and heating at 140 ° C for 60 minutes to form a cured film with a thickness of 10 m, a polarizing plate (hereinafter also referred to as “polarizing plate (a-8)”) Obtained.

 The polarizing plate (b-8) obtained had a transmittance of 47.0%, a degree of polarization of 99.9%, and the number of bright spots was 0-1.

 Further, when the reflectance was measured by making the antireflection layer side force incident on the polarizing plate (b-8) with light having a wavelength in the range of 400 to 700 nm, the reflectance for light of any wavelength was less than 1%. It was confirmed that it had a good antireflection function.

 Furthermore, when a pencil hardness test was conducted, it was confirmed that the hardness was 2H and it had good scratch resistance.

[Comparative Example 1]

The peripheral speed of the outer circumference of the mirror roll was set to 8.8 mZmin. The peripheral speed of the rubber coated roll was controlled at 8.8 mZmin. At this time, the mirror roll temperature was set to 90 ° C using an oil temperature controller, and the rubber coated roll temperature was set to 70 ° C. The resin film (a-6) was obtained. As a result of peeling off the protective film from the resin film (a-6) and measuring the characteristics as an optical film, it was confirmed that the optical axis in the thickness direction was not inclined and was in the normal direction of the film. It was. Table 1 shows the optical characteristics measurement results. The obtained resin film (a-6) had a total light transmittance of 93%. Furthermore, the number of bright spots of the resin film (a-6) is 0-1 It was.

 [0102] [Comparative Example 2]

 In Comparative Example 1, the thickness was 100 μm (the protective film thickness was the same as in Example 1) except that the resin (b-1) was used instead of the resin (a-1). A resin film (b-5) was obtained.

 As a result of peeling off the protective film from the resin film (b-5) and measuring the properties as an optical film, it was confirmed that the optical axis in the thickness direction was not inclined but was in the normal direction of the film. . Table 1 shows the optical characteristics measurement results. Further, the obtained resin film (b-2) had a total light transmittance of 92%. Furthermore, the number of bright spots of the resin film (b-2) was 0 to 1.

 [0103] [Comparative Example 3]

 The resin film (a-6) obtained in Comparative Example 1 was peeled off from the protective film, heated in a tenter to 125 ° C (Tg-5 ° C), and stretched at 300% Z min. The film was stretched 1.04 times in the longitudinal direction in the film plane. After that, it is cooled while maintaining this state for 1 minute in an atmosphere of 110 ° C (Tg—20 ° C), further cooled at room temperature, and taken out from the tenter to obtain a phase difference film (hereinafter referred to as “position”). A phase difference film (a-7) ”was also obtained.

 As a result of measuring the properties of the retardation film (a-7) as an optical film, it was confirmed that the optical axis in the thickness direction was not inclined but was in the normal direction of the film. Table 1 shows the optical characteristics measurement results. Further, the obtained retardation film (a-7) had a total light transmittance of 93%. Further, the number of bright spots in the retardation film (a-7) was 0 to 1.

[Comparative Example 4]

 The protective film is peeled from the resin film (b-5) obtained in Comparative Example 2, and heated to 145 ° C (Tg-5 ° C) in a tenter, and the film surface is stretched at a rate of 300% Z. Stretched 1.08 times in the longitudinal direction of the inward direction. After that, it is cooled while maintaining this state for 1 minute in an atmosphere of 130 ° C (Tg—20 ° C), further cooled at room temperature, and taken out of the tenter to obtain a phase difference film (hereinafter referred to as “position”). A phase difference film (b-6) ”was also obtained.

As a result of measuring the properties of the retardation film (b-6) as an optical film, it was confirmed that the optical axis in the thickness direction was inclined. Table 1 shows the optical characteristics measurement results. Further, the total light transmittance of the obtained retardation film (b-6) was 93% or more. Furthermore, the number of bright spots in the retardation film (b-6) was 01.

 [table 1]

 [0106] Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. is there.

 This application is based on a Japanese patent application filed on June 28, 2005 (Japanese Patent Application No. 2005-187659), the contents of which are incorporated herein by reference. Industrial applicability

[0107] The optical film and polarizing plate of the present invention include, for example, a mobile phone, a digital information terminal, a pager, navigation, an in-vehicle liquid crystal display, a liquid crystal monitor, a light control panel, a display for OA equipment, and a display for AV equipment. It can be used for various liquid crystal display elements, electoluminescence display elements or touch panels. It is also useful as a wave plate for use in recording and playback devices for optical discs such as CD CD-R and MD MO DVD.

Claims

The scope of the claims

 [1] An optical optical system characterized in that the optical axis in the film thickness direction is inclined by passing a melt-extruded thermoplastic norbornene-based resin film between two nozzles having different peripheral speeds. A method for producing a film.

[2] The method for producing an optical film according to claim 1, wherein the ratio of the peripheral speeds of the two rolls (the peripheral speed of roll 1 and the peripheral speed of roll 2) is 0.75 or more and 0.99 or less.

[3] The method for producing an optical film according to claim 1 or 2, wherein the surface of the two rolls having a low peripheral speed is made of rubber.

[4] The method for producing an optical film according to any one of claims 1 to 3, wherein the thermoplastic norbornene-based resin is stretched from Tg-15 ° C to Tg + 10 ° C based on the glass transition temperature (Tg). .

 [5] A thermoplastic norbornene-based resin film, wherein the optical axis in the film thickness direction is inclined by 3 to 40 degrees! /, The optical film obtained by the production method according to any one of claims 1 to 4 .

6. The optical film according to claim 5, wherein the in-plane retardation (RO) iS is 5 to 300 nm.

[7] The polarizing plate having a configuration in which a protective film is laminated on each of both surfaces of the polarizing film, and the protective film laminated on at least one surface of the polarizing film is the optical film according to claim 5 or 6. .