KR20080020534A - Optical film roll and method of making the same - Google Patents

Abstract

An optical film roll and a manufacturing method for the same are provided to produce the uniform optical film without optical non-uniformity by using a protection film having a little fisheye. An optical film roll is formed by laminating and winding an optical film containing cycloolefin resin and a protection film. The number of fisheyes having a diameter over 30 micrometers is below five/m^2. The mean roughness of a center line of the protection film is 0.005~0.05 micrometers. The protection film contains polyolefin resin. Therefore, fine uneven portions are not formed on the surface of the optical film and optical non-uniformity is prevented by reducing the number of fisheyes in the protection film, even if the optical film roll is stored for a long time.

Description

Optical film roll, and its manufacturing method {OPTICAL FILM ROLL AND METHOD OF MAKING THE SAME}

This invention relates to the optical film roll formed by laminating | stacking the optical film and protective film containing cyclic olefin resin. When the optical film roll in which the protective film of this invention is laminated by winding is used as various optical films, such as a polarizing plate and a retardation plate, this protective film is used for surface protection, and such a protective film is used for a liquid crystal display panel. It adheres to the surface, and is used for protection of various image display apparatuses, such as an organic electroluminescence display, such as a liquid crystal display device, and a PDP.

In general surface protection films, an adhesive layer is provided on base films, such as polyethylene terephthalate and polyethylene. The surface protection film is bonded to the to-be-protected body through the pressure-sensitive adhesive layer to prevent scratches, contamination, and the like. For example, optical films, such as a polarizing plate and a retardation plate, are mentioned as an optical to-be-protected body.

One side of these optical films is protected by a surface protection film in various manufacturing processes. On the other hand, an adhesive layer is provided in the opposite surface of an optical film. Moreover, the peeling liner (separator) is coat | covered on this adhesive layer. The optical film with a surface protection film produced in this way is preserve | saved in the state wound up in roll shape, or it is cut-processed according to the magnitude | size of a liquid crystal cell, and these are piled up superimposed and stored in a sheet | leaf type etc. Although these processes are normally performed in a clean room, it is difficult to completely remove micro foreign substances, such as dust generated from an operator and an inspector, punching waste at the time of punching, and dust at the time of transport.

By the way, when a micro foreign material mixes between the layers of a roll and the superimposed film, the press marks by this foreign material generate | occur | produce. If pressure marks appear on the optical film itself, they are not usable in appearance. Moreover, compared with an optical film, an adhesive layer has a low elasticity modulus and it exists in the tendency for a pressurization to occur easily. When press marks generate | occur | produce in an adhesive layer, when bonding an optical film to an LCD panel via an adhesive layer, there exists a possibility that air may be drawn in a recessed part, and it may become a display defect.

In order to solve this problem, Patent Document 1 proposes a surface protective film provided with a foreign matter absorbing layer on one side of a base film.

However, the foreign matter absorbing layer itself is separately accepted in addition to the protective film and the base film, and the installation of this layer itself has one more process, which not only complicates the process when manufacturing the optical film, but also increases the cost and economics. Not as a benefit.

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2005-125659

An object of the present invention is to provide a homogeneous and optically non-uniform optical film by suppressing foreign matter in the protective film as much as possible.

The present invention relates to an optical film roll obtained by laminating an optical film containing a cyclic olefin resin and a protective film, wherein the number of fish eyes having a diameter of 30 μm or more in the protective film is 5 / m 2 or less. will be.

Here, it is preferable that cyclic olefin resin is a (co) polymer of the compound represented by following formula (1).

<Formula 1>

(In the formula 1, R ¹ to R ⁴ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or monovalent other organic group, and each may be the same or different, and any of R ¹ to R ⁴ Two of may combine with each other to form a monocyclic or polycyclic structure, m is 0 or a positive integer, p is 0 or a positive integer)

In addition, the center line average roughness Ra of the protective film is preferably 0.005 to 0.05 μm.

Moreover, it is preferable that the said protective film contains polyolefin resin.

Next, this invention superimposes and winds the optical film containing cyclic olefin resin, and the protective film whose number of fish eyes of 30 micrometers or more in diameter is 5 micrometers or less, and wound up. will be.

According to the present invention, in the conventional optical film roll, when the protective film having the fish eye laminated on the optical film is pressed on the optical film surface for a long time, it leads to minute unevenness and optical unevenness of the surface. When a small protective film is used, a homogeneous optical film without optical nonuniformity is obtained.

<< optical film >>

The optical film of this invention is an optical film containing cyclic olefin resin.

<Cyclic olefin resin>

As cyclic olefin resin used for the optical film of this invention, the following (co) polymer is mentioned.

(1) The ring-opening polymer of the specific monomer represented by the said Formula (1).

(2) The ring-opening copolymer of the specific monomer and copolymerizable monomer represented by the said Formula (1).

(3) Hydrogenated (co) polymer of the ring-opening (co) polymer of (1) or (2).

(4) A hydrogenated (co) polymer after cyclizing the ring-opening (co) polymer of (1) or (2) by a Friedel Crafts reaction.

(5) Saturated copolymer of the specific monomer and unsaturated double bond containing compound represented by said Formula (1).

(6) An addition type (co) polymer of at least one monomer selected from a specific monomer represented by the formula (1), a vinyl cyclic hydrocarbon monomer and a cyclopentadiene monomer and a hydrogenated (co) polymer thereof.

(7) The alternating copolymer of the specific monomer and acrylate represented by the said Formula (1).

<Specific monomer>

Although the following compounds are mentioned as a specific example of the said specific monomer, This invention is not limited to these specific examples.

Bicyclo [2.2.1] hept-2-ene,

Tricyclo [4.3.0.1 ^2,5 ] -8-decene,

Tricyclo [4.4.0.1 ^2,5 ] -3-undecene,

Tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

^Pentacyclo [6.5.1.1 ^{3,6 2,7} .0 ^9,13 ] -4- ^pentadecene ,

5-methylbicyclo [2.2.1] hept-2-ene,

5-ethylbicyclo [2.2.1] hept-2-ene,

5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,

5-methyl-5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,

5-cyanobicyclo [2.2.1] hept-2-ene,

8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-ethoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-n-propoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-isopropoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-n-butoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-methyl-8-ethoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-methyl-8-n-propoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-methyl-8-isopropoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-methyl-8-n-butoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

5-ethylidenebicyclo [2.2.1] hept-2-ene,

8-ethylidenetetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

5-phenylbicyclo [2.2.1] hept-2-ene,

8-phenyl-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,

5-fluorobicyclo [2.2.1] hept-2-ene,

5-fluoromethylbicyclo [2.2.1] hept-2-ene,

5-trifluoromethylbicyclo [2.2.1] hept-2-ene,

5-pentafluoroethylbicyclo [2.2.1] hept-2-ene,

5,5-difluorobicyclo [2.2.1] hept-2-ene,

5,6-difluorobicyclo [2.2.1] hept-2-ene,

5,5-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,

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

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] hept-2-ene,

5,5,6,6-tetrafluorobicyclo [2.2.1] hept-2-ene,

5,5,6,6-tetrakis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,

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

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

5,5,6-trifluoro-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,

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

5,6-difluoro-5-heptafluoro-iso-propyl-6-trifluoromethylbicyclo [2.2.1] hept-2-ene,

5-chloro-5,6,6-trifluorobicyclo [2.2.1] hept-2-ene,

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

5,5,6-trifluoro-6-trifluoromethoxybicyclo [2.2.1] hept-2-ene,

5,5,6-trifluoro-6-heptafluoropropoxybicyclo [2.2.1] hept-2-ene,

8-fluorotetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-fluoromethyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-difluoromethyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-trifluoromethyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-pentafluoroethyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene

8,8-difluorotetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,9-difluorotetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-methyl-8-trifluoromethyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8,9-trifluorotetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8,9-tris (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8,9,9-tetrafluorotetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8,9,9-tetrakis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8-difluoro-9,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,9-difluoro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8,9-trifluoro-9-trifluoromethyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8,9-trifluoro-9-trifluoromethoxytetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,8,9-trifluoro-9-pentafluoropropoxytetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-fluoro-8-pentafluoroethyl-9,9-bis (trifluoromethyl) tetracyclo [4. 4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,9-difluoro-8-heptafluoroiso-propyl-9-trifluoromethyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8-chloro-8,9,9-trifluorotetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8,9-dichloro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

8- (2,2,2-trifluoroethoxycarbonyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] -3-dodecene,

(Ethoxycarbonyl 2,2,2-trifluoroethyl) 8-methyl-8 and the like can be mentioned tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene.

These can be used individually by 1 type or in combination of 2 or more types.

Among the specific monomers, R ¹ and R ^{3 in} Formula 1 are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, more preferably 1 to 4, particularly preferably 1 to 2 carbon atoms, and R ² and R ⁴ are A hydrogen atom or a monovalent organic group, at least one of R ² and R ⁴ represents a polar group having a polarity other than a hydrogen atom and a hydrocarbon group, m is an integer of 0 to 3, p is an integer of 0 to 3, and Preferably m + p = 0-4, More preferably, it is 0-2, Especially preferably, m = 1, p = 0. The specific monomer whose m = 1, p = 0 is preferable at the point which is excellent in mechanical strength, while the glass transition temperature of cyclic olefin resin obtained is high.

As a polar group of the said specific monomer, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, a cyano group, etc. are mentioned, These polar groups can be couple | bonded through coupling groups, such as a methylene group. Moreover, the hydrocarbon group etc. which the bivalent organic group which has polarity, such as a carbonyl group, an ether group, a silyl ether group, a thioether group, and an imino group, couple | bond and couple | bond are mentioned as a polar group. In these, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, or an allyloxycarbonyl group is preferable, and an alkoxycarbonyl group or allyloxycarbonyl group is especially preferable.

In addition, R ² and R one or more of the ^4, the formula - (CH _{2) n} polar group of monomers represented by COOR is, had excellent adhesion to the resulting cycloolefin resin has a high glass transition temperature and low moisture absorption, a variety of materials It is preferable at the point. In the formula according to the specific polar group, R is a hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 4, particularly preferably 1 to 2 carbon atoms, preferably an alkyl group. In addition, n is usually 0 to 5, but a smaller value of n is preferable because the glass transition temperature of the cyclic olefin resin obtained is higher, and a specific monomer having n of 0 is preferable in that its synthesis is easy. .

In the above formula (1), R ¹ or R ³ is preferably an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2, particularly a methyl group, and particularly the alkyl group described above. It is preferable that the specific polar group represented by the formula-(CH ₂ ) _n COOR is bonded to the same carbon atom as the carbon atom to which the specific polar group is bonded, in that the hygroscopicity of the obtained cyclic olefin resin can be lowered.

<Copolymerizable monomer>

Specific examples of the copolymerizable monomer include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene and dicyclopentadiene.

As carbon number of a cycloolefin, 4-20 are preferable and 5-12 are more preferable. These can be used individually by 1 type or in combination of 2 or more types.

The preferred use range of the specific monomer / copolymerizable monomer is 100/0 to 50/50 by weight, more preferably 100/0 to 60/40.

<Opening polymerization catalyst>

In this invention, the ring-opening polymerization reaction for obtaining (1) the ring-opening polymer of a specific monomer, and (2) the ring-opening copolymer of a specific monomer and a copolymerizable monomer is performed in presence of a metathesis catalyst.

This metathesis catalyst comprises (a) at least one member selected from compounds of W, Mo, and Re, (b) Deming periodic table of Group IA elements (e.g. Li, Na, K, etc.), Group IIA elements (e.g., Mg, Ca, etc.), Group IIB elements (e.g., Zn, Cd, Hg, etc.), Group IIIA elements (e.g., B, Al, etc.), Group IVA elements (e.g., Si, Sn, Pb, etc.) Or a compound of a group IVB element (e.g., Ti, Zr, etc.), and a catalyst comprising a combination with one or more selected from those having one or more of the above element-carbon bonds or the above element-hydrogen bonds. In this case, in order to increase the activity of the catalyst, the (c) additive described later may be added.

As a representative example of a compound of W, Mo, or Re suitable as the component (a), Japanese Patent Laid-Open No. 1-32626 such as WCl ₆ , MoCl ₆ , ReOCl _3, etc. The compound described in the 17th line of upper right column is mentioned.

(b) Specific examples of the _{component, nC 4 H 9 Li, (} C 2 H 5) 3 Al, (C 2 H 5) 2 AlCl, (C 2 H 5) 1.5 AlCl 1 .5, (C 2 H 5) AlCl ₂ , methylalumoxane, LiH, etc. The compound described in Unexamined-Japanese-Patent No. 1-32626 (8th page upper right column 18th line-8th page right lower column 3 row) is mentioned.

As representative examples of the component (c), which is an additive, alcohols, aldehydes, ketones, amines, and the like can be preferably used. The left top column can use the compounds disclosed in line 17.

As the usage-amount of a metathesis catalyst, the "(a) component: specific monomer" is a range which is usually 1: 500-1: 50,000 in the molar ratio of the said (a) component and a specific monomer, Preferably it becomes 1: 1,000-1: 10,000. Range.

The ratio of the component (a) and the component (b) is in the range of 1: 1 to 1:50, preferably 1: 2 to 1:30, in terms of metal atomic ratio.

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

<Solvent for Polymerization Reaction>

As a solvent (solvent constituting a molecular weight regulator solution, a solvent of a specific monomer and / or metathesis catalyst) used in the ring-opening polymerization reaction, for example, alkanes such as pentane, hexane, heptane, octane, nonane, decane, cyclohexane, Cycloalkanes such as cycloheptane, cyclooctane, decalin, norbornane, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, chlorobutane, bromohexane, methylene chloride, dichloroethane, hexamethylene dibromide, Halogenated alkanes such as chlorobenzene, chloroform and tetrachloroethylene, compounds such as aryl halide, saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, iso-butyl acetate, methyl propionate and dimethoxyethane, dibutyl ether And ethers such as tetrahydrofuran and dimethoxyethane. These may be used alone or in combination. Of these, aromatic hydrocarbons are preferred.

As a usage-amount of a solvent, "a solvent: specific monomer (weight ratio)" is the quantity which is usually 1: 1-10: 1, Preferably it is the quantity which becomes 1: 1-5: 1.

<Molecular weight regulator>

Although molecular weight control of the ring-opening (co) polymer obtained can be performed also by polymerization temperature, the kind of catalyst, and the kind of solvent, in this invention, it adjusts by coexisting a molecular weight modifier in a reaction system.

Here, as a preferable molecular weight modifier, alpha olefins and styrene, such as ethylene, a propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc. Among these, 1-butene and 1-hexene are especially preferable.

These molecular weight modifiers can be used individually or in mixture of 2 or more types.

As a usage-amount of a molecular weight modifier, it becomes 0.005 to 0.6 mol, Preferably it is 0.02 to 0.5 mol with respect to 1 mol of specific monomers provided for a ring-opening polymerization reaction.

(2) In order to obtain a ring-opening copolymer, although a specific monomer and a copolymerizable monomer can be ring-opened-copolymerized in a ring-opening polymerization process, conjugated diene compounds, such as polybutadiene and polyisoprene, styrene-butadiene copolymer, and ethylene-nonconjugated A specific monomer may be ring-opened-polymerized in the presence of an unsaturated hydrocarbon-based polymer including two or more carbon-carbon double bonds in a main chain such as a diene copolymer or polynorbornene.

Although the ring-opening (co) polymer obtained as mentioned above can be used as it is, the (3) hydrogenated (co) polymer obtained by further hydrogenating this is useful as a raw material of resin with high impact resistance.

<Hydrogenated Catalyst>

The hydrogenation reaction is a conventional method, i.e., a hydrogenation catalyst is added to a solution of a ring-opening polymer, and hydrogen gas at atmospheric pressure to 300 atmospheres, preferably 3 to 200 atmospheres, is 0 to 200 캜, preferably 20 to 180 It is carried out by acting at 占 폚.

As a hydrogenation catalyst, what is used for the hydrogenation reaction of a normal olefinic compound can be used. As this hydrogenation catalyst, a heterogeneous catalyst and a homogeneous catalyst are mentioned.

As a heterogeneous catalyst, the solid catalyst which supported noble metal catalyst substances, such as palladium, platinum, nickel, rhodium, ruthenium, on support | carriers, such as carbon, a silica, alumina, titania, is mentioned. As the homogeneous catalyst, nickel naphthenate / triethylaluminum, nickelacetylacetonate / triethylaluminum, cobalt octate / n-butyllithium, titanocenedichloride / diethylaluminum monochloride, rhodium acetate, chlorotris (triphenyl Phosphine) rhodium, dichlorotris (triphenylphosphine) ruthenium, chlorohydrocarbonyltris (triphenylphosphine) ruthenium, dichlorocarbonyltris (triphenylphosphine) ruthenium and the like. The form of the catalyst may be powder or granular.

These hydrogenated catalysts are used in a ratio such that the ring-opening (co) polymer: hydrogenated catalyst (weight ratio) is 1: 1 × 10 ⁻⁶ to 1: 2.

In this manner, the hydrogenated (co) polymer obtained by hydrogenation has excellent thermal stability, and its properties are not deteriorated even by heating during molding and use as a product. Here, hydrogenation rate is 50% or more normally, Preferably it is 70% or more, More preferably, it is 90% or more.

Further, the hydrogenation rate of the hydrogenated (co) polymer is 50% or more, preferably 90% or more, more preferably 98% or more, most preferably 99% or more, as measured by 500 MHz and ¹ H-NMR. to be. The higher the hydrogenation rate, the better the stability to heat and light, and when the optical film of the present invention is used as a wave plate, stable characteristics can be obtained over a long period of time.

On the other hand, as for the hydrogenated (co) polymer used as cyclic olefin resin of this invention, it is preferable that the gel content contained in the said hydrogenated (co) polymer is 5 weight% or less, and it is especially preferable that it is 1 weight% or less.

In addition, as the cyclic olefin resin of the present invention, (4) hydrogenated (co) polymer after cyclizing the ring-opening (co) polymer of (1) or (2) by the Friedel Crafts reaction can also be used. .

Cyclization by Friedel Crafts Reaction

Although the method of cyclizing the ring-opening (co) polymer of (1) or (2) by Friedel Crafts reaction is not particularly limited, it is a known method using an acidic compound described in Japanese Patent Application Laid-open No. 50-154399. Can be adopted. Specific examples of the acidic compound include Lewis acids such as AlCl ₃ , BF ₃ , FeCl ₃ , Al ₂ O ₃ , HCl, CH ₃ ClCOOH, zeolite, activated clay, and brendsteadic acid.

The cyclized ring-opening (co) polymer can be hydrogenated similarly to the ring-opening (co) polymer of (1) or (2).

Moreover, as cyclic olefin resin of this invention, the saturated copolymer of the said specific monomer and unsaturated double bond containing compound can also be used.

<Unsaturated double bond containing compound>

As the unsaturated double bond-containing compound, for example, ethylene, propylene, butene, etc., preferably an olefin compound having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms.

The preferred use range of the specific monomer / unsaturated double bond containing compound is 90/10 to 40/60 by weight, more preferably 85/15 to 50/50.

In the present invention, in order to obtain a saturated copolymer of the specific monomer and the unsaturated double bond-containing compound, a conventional addition polymerization method can be used.

<Addition polymerization catalyst>

As a catalyst for synthesizing the saturated copolymer (5), at least one selected from a titanium compound, a zirconium compound and a vanadium compound, and an organoaluminum compound as a crude catalyst are used.

Here, titanium tetrachloride, titanium trichloride, etc. are mentioned as a titanium compound, bis (cyclopentadienyl) zirconium chloride, bis (cyclopentadienyl) zirconium dichloride, etc. are mentioned as a zirconium compound.

As the vanadium compound, the formula VO (OR) _a X _b or V (OR) _c X _d [where R is a hydrocarbon group and X is a halogen atom and 0 ≦ a ≦ 3, 0 ≦ b ≦ 3, 2 ≦ (a + b) ≤ 3, 0 ≤ c ≤ 4, 0 ≤ d ≤ 4, 3 ≤ (c + d) ≤ 4] or a vanadium compound thereof or an electron donating adduct thereof.

Examples of the electron donor include oxygen-containing electron donors such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, acid anhydrides and alkoxysilanes, and nitrogen-containing electrons such as ammonia, amines, nitriles and isocyanates. Electron donors and the like.

As the organoaluminum compound as the crude catalyst, at least one selected from those having at least one aluminum-carbon bond or aluminum-hydrogen bond is used.

In the above, for example, the ratio of the vanadium compound to the organoaluminum compound in the case of using a vanadium compound is 2 or more, preferably 2 to 50, particularly preferably 2 to 50, particularly preferably a ratio of aluminum atoms to vanadium atoms. Preferably in the range of 3 to 20.

As the solvent for the polymerization reaction used for the addition polymerization, the same solvent as that used for the ring-opening polymerization reaction can be used. In addition, adjustment of the molecular weight of the obtained (5) saturated copolymer is normally performed using hydrogen.

In addition, as the cyclic olefin resin of the present invention, (6) an addition type copolymer of one or more monomers selected from the above-described specific monomers and vinyl cyclic hydrocarbon monomers or cyclopentadiene monomers and hydrogenated copolymers thereof may also be used. Can be.

<Vinyl cyclic hydrocarbon monomer>

Examples of the vinyl cyclic hydrocarbon monomers include vinylcyclopentene monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene, 4-vinylcyclopentane, 4-isopropenylcyclopentane, and the like. Vinylated 5-membered ring hydrocarbon monomers such as vinylcyclopentane monomers, 4-vinylcyclohexene, 4-isopropenylcyclohexene, 1-methyl-4-isopropenylcyclohexene, and 2-methyl-4-vinylcyclohexene , Vinylcyclohexene monomers such as 2-methyl-4-isopropenylcyclohexene, vinylcyclohexane monomers such as 4-vinylcyclohexane, 2-methyl-4-isopropenylcyclohexane, styrene, and α-methyl Styrene-based monomers such as styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 4-phenylstyrene, p-methoxystyrene, d-terpene, 1-terpene , Terpene monomers such as diterpene, d-limonene, 1-limonene, dipentene, and 4-vinyl Vinylcycloheptane monomers such as cloheptene and 4-isopropenylcycloheptene, and vinylcycloheptane monomers such as 4-vinylcycloheptane and 4-isopropenylcycloheptane. Preferably they are styrene and (alpha) -methylstyrene. These can be used individually by 1 type or in combination of 2 or more types.

<Cyclopentadiene monomers>

As a cyclopentadiene type monomer used for the monomer of the (6) addition type copolymer of this invention, for example, cyclopentadiene, 1-methylcyclopentadiene, 2-methylcyclopentadiene, 2-ethylcyclopentadiene, 5 -Methylcyclopentadiene, 5,5-methylcyclopentadiene, etc. are mentioned. Preferably cyclopentadiene. These can be used individually by 1 type or in combination of 2 or more types.

The addition type (co) polymer of at least one monomer selected from the above specific monomers, vinyl cyclic hydrocarbon monomers and cyclopentadiene monomers is the same as the saturated copolymer of the above (5) specific monomers and unsaturated double bond-containing compounds. It can be obtained by a polymerization method.

In addition, the hydrogenation (co) polymer of the said addition type (co) polymer can be obtained by the same hydrogenation method as the hydrogenation (co) polymer of said (3) ring-opening (co) polymer.

As the cyclic olefin resin of the present invention, an alternating copolymer of (7) the specific monomer and acrylate can also be used.

<Acrylate>

As an acrylate used for manufacture of the alternating copolymer of the said specific monomer and acrylate of (7) of this invention, For example, C1-C1, such as methyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, etc. Carbon atoms such as heterocyclic group-containing acrylates and benzyl acrylates having 2 to 20 carbon atoms such as 20 linear, branched or cyclic alkyl acrylates, glycidyl acrylates and 2-tetrahydrofurfuryl acrylates The acrylate which has a C7-C30 polycyclic structure, such as 6-20 aromatic ring group containing acrylate, isoboroyl acrylate, and dicyclopentanyl acrylate, is mentioned.

In the present invention, (7) In order to obtain an alternating copolymer of the specific monomer and the acrylate, when the total of the specific monomer and the acrylate is 100 mol in the presence of Lewis acid, the specific monomer is usually 30 to 70 mol, The acrylate is in a ratio of 70 to 30 moles, preferably the specific monomer is 40 to 60 moles, the acrylate is in a ratio of 60 to 40 moles, particularly preferably the particular monomer is 45 to 55 moles and the acrylate is 55 Radical polymerization at a rate of from 45 to 45 moles.

(7) The amount of Lewis acid used to obtain an alternating copolymer of the specific monomer and acrylate is an amount of 0.001 to 1 mol based on 100 mol of acrylate. In addition, a known organic peroxide or azobis-based radical polymerization initiator for generating free radicals can be used, and the polymerization reaction temperature is usually -20 ° C to 80 ° C, preferably 5 ° C to 60 ° C. As the solvent for the polymerization reaction, the same solvent as that used for the ring-opening polymerization reaction can be used.

On the other hand, "alternative copolymer" as used in the present invention means that the structural units derived from the specific monomer are not adjacent to each other, that is, the neighbors of the structural units derived from the specific monomer have a structure that is necessarily a structural unit derived from acrylate. It means a copolymer, and does not negate the structure in which structural units derived from an acrylate exist adjacent.

The preferred molecular weight of the cyclic olefin resin used in the present invention is intrinsic viscosity [η] _inh (measured at 30 ° C. in chloroform), preferably 0.2 to 5 dl / g, more preferably 0.3 to 1.5 dl / g, in particular Preferably it is 0.35-0.8 dl / g, The number average molecular weight (Mn) of polystyrene conversion measured by the gel permeation chromatography (GPC) is 8,000-100,000, More preferably, it is 10,000-80,000, Especially preferably, it is 12,000-50,000 The weight average molecular weight (Mw) is preferably in the range of 20,000 to 300,000, more preferably 30,000 to 250,000, particularly preferably 40,000 to 200,000.

When the intrinsic viscosity [η] _inh , the number average molecular weight and the weight average molecular weight are in the above ranges, the heat resistance, water resistance, chemical resistance, mechanical properties of the cyclic olefin resin, and molding processability as the optical film of the present invention are improved.

The glass transition temperature (Tg) of cyclic olefin resin used for this invention is 110 degreeC or more normally, Preferably it is 110-350 degreeC, More preferably, it is 120-250 degreeC, Especially preferably, it is 120-200 degreeC. When Tg is less than 110 degreeC, since it deforms by use under high temperature conditions or secondary processing, such as coating and printing, it is unpreferable. On the other hand, when Tg exceeds 350 degreeC, shaping | molding process becomes difficult and the possibility of resin deterioration by the heat at the time of shaping | molding process becomes high.

In the cyclic olefin resin, a specific hydrocarbon system described in, for example, Japanese Patent Application Laid-Open No. 9-221577 and Japanese Patent Application Laid-Open No. 10-287732 within a range that does not impair the effects of the present invention. Resin or a known thermoplastic resin, thermoplastic elastomer, rubbery polymer, organic fine particles, inorganic fine particles and the like can be blended.

Moreover, additives, such as well-known antioxidant and ultraviolet absorber, can be added to the cyclic olefin resin of this invention in order to improve heat resistance and light resistance, in the range which does not impair the effect of this invention. For example, the phenolic compound, thiol compound, sulfide compound, disulfide compound, phosphorus compound and at least one compound selected from the group consisting of 0.01 to 100 parts by weight of the cyclic olefin resin of the present invention By adding 10 parts by weight, the heat deterioration resistance can be improved.

Phenolic Compounds:

Examples of the phenol-based compound include triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] and 1,6-hexanediol-bis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino ) -3,5-triazine, pentaerythryl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ], N, N-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnaamide), 1,3,5-trimethyl-2,4,6-tris (3,5- Di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, etc. are mentioned. have. Preferably, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5 -Di-t-butyl-4-hydroxybenzyl) benzene, pentaerythryl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] , Particularly preferably octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate].

Thiol Compounds:

Examples of the thiol-based compound include alkyl mercaptans such as t-dodecyl mercaptan and hexyl mercaptan, 2-mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, and 1-methyl-2- (methylmercapto). Benzimidazole, 2-mercapto-1-methylbenzimidazole, 2-mercapto-4-methylbenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercapto-5,6-dimethyl Benzimidazole, 2- (methylmercapto) benzimidazole, 1-methyl-2- (methylmercapto) benzimidazole, 2-mercapto-1,3-dimethylbenzimidazole, mercaptoacetic acid and the like Can be.

Sulfide compounds:

Examples of the sulfide compound include 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and 2,2-thiobis (4-methyl -6-t-butylphenol), 2,4-bis (n-octylthiomethyl) -6-methylphenol, dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodi Propionate, distearyl 3,3'-thiodipropionate, pentaerythritol tetrakis (3-laurylthiopropionate), ditridecyl 3,3'-thiodipropionate, and the like. Can be mentioned.

Disulfide Compounds:

As a disulfide type compound, bis (4-chlorophenyl) disulfide, bis (2-chlorophenyl) disulfide, bis (2, 5- dichlorophenyl) disulfide, bis (2, 4, 6- trichlorophenyl) disulfide Feed, bis (2-nitrophenyl) disulfide, ethyl 2,2'-dithiodibenzoate, bis (4-acetylphenyl) disulfide, bis (4-carbamoylphenyl) disulfide, 1,1'-di Naphthyl disulfide, 2,2'- dinaphthyl disulfide, 1,2'- dinaphthyl disulfide, 2,2'-bis (1-chlorodinaphthyl) disulfide, 1,1'-bis (2-chloronaphthyl) disulfide, 2,2'-bis (1-cyanonaphthyl) disulfide, 2,2'-bis (1-acetylnaphthyl) disulfide, dilauryl-3,3 ' -Thiodipropionic acid ester etc. are mentioned.

Phosphorus-based compound:

Examples of the phosphorus compound include tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6- Di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, etc. are mentioned.

Moreover, benzophenazole type compounds, such as 2, 4- dihydroxy benzophenone and 2-hydroxy-4- methoxy benzophenone, benzotriazole type compounds, such as N- (benzyloxycarbonyloxy) benzotriazole, or 0.01 to 3 parts by weight of oxanilide compounds such as 2-ethyloxanide and 2-ethyl-2'-ethoxyoxanilide, based on 100 parts by weight of the cyclic olefin resin of the present invention, preferably 0.05 to By adding 2 parts by weight, light resistance can be improved.

In addition, when the cyclic olefin resin according to the present invention is molded into a film or the like by melt extrusion, it is important to select an antioxidant added to prevent the resin from thermally deteriorating due to the thermal history during melt extrusion. It becomes a technical element. That is, when extending | stretching the film obtained by melt-extruding, in order not to reduce the developability of retardation or to make the fall degree as small as possible, from +20 degreeC or more than the glass transition temperature (Tg) of cyclic-olefin resin melt-extrusion It is preferable to use the hindered phenol type compound which has melting | fusing point in the temperature range of Tg + 130 degreeC, Preferably it is Tg + 30 degreeC-Tg + 130 degreeC as antioxidant.

If melting | fusing point is less than +20 degreeC than Tg of cyclic olefin resin melt-extruded, even if a hindered phenol type compound is used, when the addition amount increases, the reproducibility of phase difference may fall significantly. On the other hand, when melting | fusing point exceeds +130 degreeC than Tg of cyclic olefin resin melt-extruded, antioxidant may not melt | dissolve at the time of processing, and may be a cause of film defects, such as fisheye, and a foreign material. Moreover, even if melting | fusing point exists in Tg + 20 degreeC-Tg + 130 degreeC of cyclic olefin resin, when using compounds other than a hindered phenol type compound as antioxidant, the fall of the retardation expression may be seen.

As a specific example of the said antioxidant used preferably when shape | molding the cyclic olefin resin of this invention by melt extrusion, For example, 1,3,5-trimethyl- 2,4,6-tris (3,5- Di-t-butyl-4-hydroxybenzyl) benzene, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnaamide), tris- (3,5- Di-t-butyl-4-hydroxybenzyl) -isocyanate, tris (2,4-di-t-butylphenyl) phosphite and the like, but the present invention is not limited thereto, and these also melt. It may be inappropriate depending on the Tg of the cyclic olefin resin to be extruded. In addition, as long as the effect of this invention is not impaired, these may be used in combination or may be used independently.

The amount of these antioxidants added is usually 0.01 to 5 parts by weight, preferably 0.05 to 4 parts by weight, and more preferably 0.1 to 1.5 parts by weight with respect to 100 parts by weight of the cyclic olefin resin. When the amount of the antioxidant added is less than 0.01 part by weight, a gel tends to occur in the resin during extrusion processing, and because of this, it can be recognized as a defect on the obtained film, which is not preferable. On the other hand, when the amount of the additive exceeds 5 parts by weight, impurities may be generated during processing, and such impurities are not preferable because they cause die lines, fish eyes on films, discoloration, and the like.

Such antioxidant may be added when producing cyclic olefin resin, and may be mix | blended with the pellet of cyclic olefin resin at the time of melt extrusion.

Moreover, when shape | molding the cyclic olefin resin of this invention by melt extrusion, additives other than said antioxidant, such as a lubricant, a ultraviolet absorber, dye, or a pigment, can be used in the range which does not impair the effect of this invention. Of course, even in this case, in the case of the additive having a melting point, the melting point is preferably in the melting point range of the essential antioxidant of the present invention.

<Film forming>

As a shaping | molding method of a cyclic olefin resin film, the solvent casting method (solution casting method), the melt-extrusion method, etc. are mentioned. The solvent casting method is preferable at the point which film thickness uniformity and surface smoothness become favorable, and the melt extrusion method is preferable at the point of manufacture cost.

[Solvent Casting Method]

It does not specifically limit as a method of obtaining a cyclic olefin resin film by the solvent casting method, A well-known method is applicable. For example, a method of dissolving or dispersing the cyclic olefin resin in a solvent to form a liquid having a suitable concentration, pouring or applying on a suitable substrate, drying it, and then peeling from the substrate may be mentioned.

Although the various conditions of the method of obtaining a cyclic olefin resin film by the solvent casting method are shown below, this invention is not limited to these various conditions.

When dissolving or dispersing the cyclic olefin resin in a solvent, the concentration of the resin is usually 0.1 to 90% by weight, preferably 1 to 50% by weight, more preferably 10 to 35% by weight. When the concentration of the resin is lower than the above range, it is difficult to secure the thickness of the film, and the surface smoothness of the film is difficult to be obtained due to foaming due to evaporation of the solvent. On the other hand, when a density | concentration exceeds the said range, there exists a tendency for the thickness and surface of the cyclic olefin resin film obtained because solution viscosity becomes too high to become uniform.

In addition, the viscosity of the solution at room temperature is usually 1 to 1,000,000 mPa · s, preferably 10 to 100,000 mPa · s, more preferably 100 to 50,000 mPa · s, particularly preferably 1,000 to 40,000 mPa · s.

As said solvent, For example, aromatic solvents, such as benzene, toluene, xylene; Cellosolve solvents such as methyl cellosolve, ethyl cellosolve and 1-methoxy-2-propanol; Ketone solvents such as diacetone alcohol, acetone, cyclohexanone, methyl ethyl ketone, and 4-methyl-2-pentanone; Ester solvents such as methyl lactate and ethyl lactate; Cycloolefin solvents such as cyclohexane, ethylcyclohexane and 1,2-dimethylcyclohexane; Halogen-containing solvents such as 2,2,3,3-tetrafluoro-1-propanol, methylene chloride and chloroform; Ether solvents such as tetrahydrofuran and dioxane; Alcohol solvent, such as 1-pentanol and 1-butanol, etc. are mentioned.

Further, in addition to SP value (solubility parameter) of 10 to 30 (MPa ^1/2), preferably from 10 to 25 (MPa ^1/2), more preferably from 15 to 25 (MPa ^1/2), particularly preferably Advantageously when using a solvent in the range of 15 to 20 (MPa ^1/2), it is possible to obtain a good surface uniformity and a cyclic olefin based resin film having an optical property.

The said solvent may be used individually by 1 type, and may mix and use 2 or more types. In the case of a mixing system, it is preferable to make the range of SP value in the case of using a mixing system within the said range. At this time, the value of the SP value in the mixed system can be predicted by the weight ratio. For example, in the two kinds of mixing, when the respective weight fractions are W1 and W2 and the SP value is SP1 and SP2, the SP value of the mixed system Can be obtained by

SP value = W1, SP1 + W2, SP2

As a method of apply | coating the said solution on a base material, the spraying method, the brushing method, the roll coating method, the spin coating method, the dipping method, etc. can be employ | adopted, for example besides the method of using a die | dye or a coater. On the other hand, it can control thickness, surface smoothness, etc. by repeating application | coating.

As said base material, a metal drum, a steel belt, polyester films, such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), a polytetrafluoroethylene (brand name; Teflon (trademark)) belt, etc. are mentioned, for example. Can be.

There is no restriction | limiting in particular about the drying process of the said solvent casting method, It can carry out by the method generally used, for example, the method of passing the inside of a drying furnace through many rollers. However, if bubbles are generated due to evaporation of the solvent in the drying step, the properties of the film are significantly reduced. Therefore, in order to avoid this, it is preferable to use the drying step in two or more steps, and to control the temperature and air volume in each step. Do. In particular, the drying process until peeling from a base material is made into two or more steps, and the temperature in the 1st-step drying process is 0-50 degreeC, Preferably it is 10-40 degreeC, and in the drying process after 2nd step When the temperature is 50 to 200 ° C, preferably 70 to 180 ° C, the value of Rth (550) of the obtained film can be adjusted to a preferable range (30 to 300 nm), which is very preferable.

Further, to the retardation R0 (550) in the film plane of 0 to 300 ㎚, to stress _F T (MPa) of the film foil receiver is in the range of 0.01 MPa≤T _F ≤5 MPa is preferred. If T _F is less than 0.01 MPa, it cannot be peeled off well, whereas if the film is peeled off from the roll in excess of 5 MPa, it becomes R0 (550)> 300 nm, which is not preferable.

Here, when the maximum refractive index in a film plane at a light ray wavelength of 550 nm is nx, the refractive index of the direction orthogonal to nx in a film plane is ny, the refractive index of a film thickness direction is nz, and a film thickness is d [nm], In-plane phase difference R0 (550) [nm] = (nx-ny) xd, It is represented by phase difference Rth (550) [nm] = {(nx + ny) / 2-nz} xd of the film thickness direction.

On the other hand, when the phase difference R0 (550) in a film surface exceeds 300 nm, light leakage may occur easily and contrast ratio may fall.

Moreover, when the value of the phase difference Rth (550) of the film thickness direction exists in the said range, when the said optical film is used for the objective of viewing angle compensation, the contrast ratio of the obtained liquid crystal panel is large, a color shift will become small, and the viewing angle characteristic will become very favorable. .

[Melt extrusion method]

It does not specifically limit as a method of obtaining a cyclic olefin resin film by the solvent casting method, A well-known method is applicable. For example, a method of extruding a cyclic olefin resin in a molten state from a die attached to an extruder, pressing the resin onto a mirror surface roll surface, then cooling, peeling and sheeting is mentioned.

As a method of melting the cyclic olefin resin, a method of melting the resin by an extruder is preferable, and the molten resin is quantitatively supplied by a gear pump, filtered through a metal filter or the like to remove impurities, and then in a film form with a die. The method of extrusion while shaping is preferable.

Examples of a method of cooling and sheeting the film extruded from the die include a nip roll method, an electrostatic application method, an air knife method, a calender method, a single side belt method, a double side belt method, and a triaxial roll method. In order to manufacture a sheet | seat, a single-sided belt type, the sheet manufacturing apparatus called a sleeve type especially, an electrostatic application system, etc. are used preferably. For example, the film manufacturing apparatus in which a mirror surface roll and a metal belt are arrange | positioned under the discharge port of a die | dye, and the peeling roll is arrange | positioned so that it may be arranged in parallel with the said mirror surface roll is mentioned. The metal belt is held in a tensioned state by two retaining rolls provided in contact with the inner surface thereof. The resin discharged from the discharge port is pinched by passing between the mirror surface roll and the metal belt, transferred to the mirror surface roll, cooled, and then peeled by a peeling roll to form a film. Moreover, the method which improves the surface property of a film, without giving optical deformation by attaching a film to a mirror surface roll side from the charging electrode arrange | positioned so that it may oppose each other to the mirror surface roll below the ejection opening of a die at the position of the both ends of the film discharged | emitted. And the like are also preferred methods.

As the extruder, any of single screw, twin screw, planetary type, co-kneader and the like can be used, but preferably, a single screw extruder is used. Moreover, as a screw shape of an extruder, although a vent type, a tip dulge mage type, a full flight type, etc. are mentioned, Preferably it is a full flight type. As the gear pump used for the metering of the resin, both an internal lubrication type and an external lubrication type can be used.

Examples of the filter used for filtration of foreign matter include leaf disc type, candle filter type, leaf type, and screen mesh. Among them, the leaf disc type is most preferred for the purpose of reducing the residence time distribution of the resin, and the nominal mesh that means the filter mesh is 20 µm or less, preferably 10 µm or less, and more preferably 5 µm or less. Most preferably it is 3 micrometers or less. If the nominal mesh is larger than 20 µm, it is difficult to remove the gel or the like in addition to the visible foreign matter, which is not preferable as a filter for making an optical film.

As the die, it is essential to make the resin flow inside the die uniform. In order to maintain the film uniformity, it is essential that the pressure distribution inside the die in the vicinity of the die exit is constant in the width direction. As satisfying these conditions, a manifold die, a fish tail die, a coat hanger die, etc. can be used, Among these, a coat hanger die is preferable. In addition, a bending lip type is preferable for adjusting the flow rate of the die. Moreover, the die | dye with the function which performs thickness adjustment by the automatic control by a heat bolt system is especially preferable. Attaching the choke bar for adjusting the flow rate or attaching the lip block for adjusting the thickness may cause a step in the attachment part, induce air or the like in the gap between the attachment parts, or cause discoloration, or It is not desirable because it can cause. The discharge port of the die is preferably made of a coating such as cemented carbide coating such as tungsten carbide. In addition, as a material of a die, stainless materials, such as SCM type steel and SUS, etc. are mentioned, It is not limited to these. In addition, the surface is coated with chromium, nickel, titanium, etc., a film such as TiN, TiAlN, TiC, CrN, DLC (diamond-like carbon) is formed by PVD (Physical Vapor Deposition) method, or other ceramics. The thermal sprayed, the nitrided surface, etc. can be used. Since such a die has high surface hardness and low friction with the resin, it is preferable in that it can prevent soot and the like from being mixed in the transparent resin sheet obtained, and also prevents the occurrence of a die line.

It is preferable that a mirror roll has a heating means and a cooling means inside, and its surface roughness is 0.5 micrometer or less, especially 0.3 micrometer or less. It is preferable to use what was plated by the metal roll as a mirror surface roll, and what carried out chromium plating, electroless nickel plating, etc. is especially preferable.

As for the heating method of a mirror surface roll, a jacket type oil temperature control system, a dielectric heating system, etc. are used as a preferable method. Although the heating method of a roll is not specifically limited, It is preferable that the temperature of a roll does not have a temperature difference in the film film forming range, and the temperature difference of an acceptable roll becomes like this. Preferably it is less than 2 degreeC, More preferably, it is within 1 degreeC.

As a metal belt used for a single-sided belt type apparatus and a sleeve type take-out apparatus, it is preferable to use an endless belt without a seamless. Stainless, nickel, etc. can be used as a material which comprises a metal belt. Moreover, it is preferable that the holding roll which hold | maintains a metal belt is coat | covered with the silicone rubber, the elastomer which has other heat resistance, etc. on the surface. The thickness of the metal belt is preferably 0.1 to 0.4 mm. If the thickness of the metal belt is less than 0.1 mm, the bending is large and may cause scratches directly on the belt. On the other hand, when thickness is larger than 0.4 mm, since it does not follow a film and deform | transforms at the time of processing, it is not preferable.

By the said apparatus, a film is manufactured as follows, for example.

Generally, before the cyclic olefin resin is introduced into the extruder, the resin is dried at an appropriate temperature of Tg or less of the resin for the purpose of removing water, gas (oxygen, etc.), residual solvent, and the like contained in the resin in advance. Do it.

As the dryer used for drying, an inert gas circulation type dryer and a vacuum dryer are used preferably. In addition, in order to absorb moisture in the hopper or to suppress the absorption of oxygen, it is also preferable to use a vacuum hopper capable of sealing the hopper with an inert gas such as nitrogen or argon, or maintaining it under reduced pressure.

The extruder cylinder is preferably sealed with an inert gas such as nitrogen or argon in order to prevent the resin from being oxidized during generation of melt extrusion and gel.

The cyclic olefin resin melted by the extruder is extruded in a sheet form from the die discharge port toward the lower side in the vertical direction. The temperature distribution at the die outlet is preferably controlled to ± 1 ° C. or less in order to reduce the melt viscosity difference of the resin.

Then, the extruded resin is pinched by the mirror roll and the metal belt, and cooled. And the sheet-like film is manufactured by peeling resin transferred to the mirror surface roll surface from the surface of a mirror surface roll with the peeling roll.

In the present invention, the processing temperature of the resin, that is, the set temperatures of the extruder and the die, is Tg + 100 ° C. or higher of the resin and Tg + 200 in terms of being able to discharge the resin in a molten state having a uniform fluidity from the die and suppressing the deterioration of the resin. It is preferable that it is below C.

Further, the pressure when the resin is pinched by the mirror surface roll and the metal belt, that is, when the resin is transferred to the mirror surface roll, is preferably 0.01 to 0.8 MPa, particularly preferably 0.1 to 0.6 MPa, in terms of surface pressure. Especially preferably, it is 0.15 to 0.45 MPa. When it is said pressure, since the value of Rth (550) of the obtained film can be adjusted in a suitable range, it is very preferable.

At this time, in order to set the angle θ formed between the optical axis in the film thickness direction and the normal to the film plane to be 0 to 3 °, it is preferable to close the circumferential speed of the mirror surface roll and the metal belt. As a preferable range, when the peripheral speed of a mirror surface roll is set to 1.00, the peripheral speed of a metal belt is 0.95-1.05, Especially preferably, it is 0.99-1.01. If it is the range of such a circumferential speed, it becomes possible to manufacture that the angle (theta) which the optical axis of a film thickness direction and the normal with respect to a film surface make is 0-3 degrees. On the other hand, when (theta) exceeds 3 degrees, since color shift and contrast ratio change according to the orientation which observes a liquid crystal panel, it becomes unsymmetrical with respect to the transmission axis of a polarizing plate, and is unpreferable.

Further, to the retardation R0 (550) in the film plane of 0 to 300 ㎚, when a condition of the film peeled off to a peeling temperature _{T t} (℃), peeling stress T _F (MPa), respectively, Tg-30 ℃ ≤ t _t is in the range of _{≤Tg + 5 ℃, 0.01 MPa≤T F} ≤5 MPa is preferred. When the film is peeled from the roll beyond this range, it becomes R0 (550)> 300 nm, which is not preferable.

<Film stretching processing>

The optical film of this invention can also extend | stretch the optical film obtained by the casting | flow_spreading method or the melt-extrusion method as mentioned above. As a stretching process method in this case, a well-known uniaxial stretching method or the biaxial stretching method is mentioned specifically ,. In other words, the uniaxial stretching method by the tenter method, the compression stretching method between rolls, the longitudinal monoaxial stretching method using two pairs of rolls with different circumferences, or the biaxial stretching method in which the horizontal single axis and the longitudinal single axis are combined, and the inflation method The stretching method by and the like can be used.

In the case of the uniaxial stretching method, the stretching speed is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, more preferably 100 to 1,000% / min, particularly preferably 100 to 500% / Minutes.

In the biaxial stretching method, stretching may be performed in two directions at the same time, or stretching may be performed in a direction different from the initial stretching direction after uniaxial stretching. Under the present circumstances, since the crossing angle of the two extending axes for controlling the shape of the refractive index ellipsoid of the film after extending | stretching is determined according to a desired characteristic, it is not specifically limited, Usually, it is the range of 120-60 degree. In addition, the stretching speed may be the same or different in each stretching direction, and is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, more preferably 100 to 1,000% / min. And particularly preferably 100 to 500% / min.

Although the stretching processing temperature is not particularly limited, it is usually Tg ± 30 ° C, preferably Tg ± 15 ° C, more preferably Tg-5 ° C to Tg + 15 ° C based on the glass transition temperature Tg of the resin of the present invention. Range. By setting it in the said range, it becomes possible to suppress generation | occurrence | production of phase difference nonuniformity, and it is preferable at the point which becomes easy to control an index ellipsoid.

The draw ratio is not particularly limited because it is determined according to desired characteristics, but is usually 1.01 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.

Although the stretched film can be cooled as it is, it is preferable to heat-fix and hold at least 10 seconds or more, preferably 30 seconds to 60 minutes, more preferably 1 minute to 60 minutes under a temperature atmosphere of Tg-20 ° C to Tg. Do. Thereby, the time-dependent change of the phase difference of transmitted light is small, and a stable phase difference film is obtained.

The dimensional shrinkage rate by heating of the optical film of the present invention when not stretching is usually 5% or less, preferably 3% or less, more preferably 1% when heating at 100 ° C. is performed for 500 hours. Hereinafter, Especially preferably, it is 0.5% or less.

Moreover, the dimensional shrinkage rate by heating of the optical film of this invention is 10% or less normally, when it heats at 100 degreeC for 500 hours normally, Preferably it is 5% or less, More preferably, it is 3% or less, Especially preferably, 1% or less.

In order to make a dimensional shrinkage rate into the said range, in addition to selection of the specific monomer and copolymerizable monomer which are the raw materials of the resin of this invention, it can control by a casting method or an extending | stretching method.

In the stretched film as described above, molecules are oriented by stretching to provide a phase difference to the transmitted light, and the phase difference can be controlled by the stretching ratio, the stretching temperature or the thickness of the film. For example, when the film thickness before extending | stretching is the same, since the absolute value of the phase difference of transmitted light tends to become large, the film with a big draw ratio is large, and by changing a draw ratio, the retardation film which provides a desired phase difference to transmitted light can be obtained. On the other hand, when the draw ratio is the same, since the absolute value of the phase difference of transmitted light tends to become large as the thickness of the film before extending | stretching is thick, the phase difference film which provides a desired phase difference to transmitted light can be obtained by changing the thickness of the film before extending | stretching. In addition, since the absolute value of the phase difference of transmitted light tends to become large in the above drawing process temperature range, the retardation film which provides a desired phase difference to transmitted light by changing extending | stretching temperature can be obtained.

The thickness of the optical film (retardation film) obtained by extending | stretching as mentioned above is 100 micrometers or less normally, Preferably it is 100-20 micrometers, More preferably, it is 80-20 micrometers. By making thickness thin, it can respond largely to the miniaturization and thin film required for the product of the field | area where retardation film is used. Here, in order to control the thickness of retardation film, it can control by controlling the thickness of an optical film before extending | stretching, or controlling a draw ratio. For example, the thickness of a retardation film can be made thinner by thinning the optical film before extending | stretching or making a draw ratio comparatively large.

On the other hand, the amount of residual solvent in the film used for the optical film of this invention is 10 weight% or less normally, Preferably it is 5 weight% or less, More preferably, it is 1 weight% or less, Especially preferably, it is 0.5 weight% or less to be. Here, when the amount of the residual solvent exceeds the above range, there is a tendency for the dimensional change over time to increase when actually used, and further, the Tg is lowered due to the residual solvent, which may lower the heat resistance.

On the other hand, the thickness distribution of the film is usually within ± 10% of the average value, preferably within ± 5%, more preferably within ± 1%, particularly preferably within ± 0.5%. In addition, the variation in thickness per cm is usually 1% or less, preferably 0.1% or less, more preferably 0.01% or less, particularly preferably 0.005% or less. By controlling the thickness distribution of an optical film in the said range, when performing an extending | stretching process in some cases, it can prevent that retardation nonuniformity and the orientation nonuniformity of an optical axis arise.

Here, thickness distribution is the value measured in 1 mm intervals by the film thickness measuring apparatus "Profiler 140E" by MOCON.

<< protective film >>

The protective film of this invention is for protecting the surface of the optical film containing cyclic olefin resin, and the said optical film and a protective film are laminated and wound, and comprise the optical film roll of this invention.

Here, the protective film of this invention may have an adhesive layer on one side of the said protective film, or may have an adhesive layer on one side of the said protective film, and a conductive layer on the other side.

As a material of the protective film used for this invention, what is excellent in transparency, mechanical strength, heat stability, moisture shielding, isotropy, etc. is preferable, For example, polyester-based polymers, such as polyethylene terephthalate and a polyethylene naphthalate, diacetyl cellulose Cellulose polymers such as triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene and acrylonitrile styrene copolymer (AS resin), polycarbonate polymers, polyethylene, polypropylene, cyclo Olefin-based resins having a norbornene structure, EP (D) M such as ethylene-propylene copolymers, amide-based polymers such as vinyl chloride-based polymers, nylon and aromatic polyamides, imide-based polymers, sulfone-based polymers, and poly Ethersulfone polymer, polyether ether ketone polymerization And polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, and blends of the above polymers. . Preferably, it is olefin resin, such as polyethylene and a polypropylene, from the surface which prevents a scratch by the protective film of an optical film.

Various additives, such as a light stabilizer, a ultraviolet absorber, antioxidant, a filler, can be mix | blended with a protective film as needed. Moreover, well-known surface modification processes, such as a corona treatment, can also be performed.

It is preferable that the film thickness of a protective film is 5-50 micrometers, More preferably, it is 5-30 micrometers. If it is thinner than 5 mu m, the manufacturing tends to be difficult, while if it is thicker than 50 mu m, the price tends to be expensive.

The protective film used for this invention needs that the fish eye whose diameter (phi) contained in the said film is 30 micrometers or more is 5 pieces / m <2> or less. Preferably it is 1 piece / m <2> or less. Here, fish-eye means what melt | dissolves undesired materials and the deterioration of a material in the film, when manufacturing a film by kneading | mixing, an extrusion drawing method, or the casting method by heat-melting the material used as a protective film.

On the other hand, the size of the diameter of the fish eye also varies depending on the material, but is about 10 μm to 1 mm and the height from the film surface is about 1 to 50 μm.

Here, the fish eye size measuring method can be measured by an optical microscope, a contact surface roughness meter, or a scanning electron microscope, for example. On the other hand, the diameter φ of the fish eye means the maximum diameter.

In the protective film of this invention, when the fish eye of 30 micrometers or more in diameter exceeds 5 / m <2>, when the optical film and a protective film are laminated | stacked and made into an optical film roll, the protective film which has a fish eye will be optical for a long term. When pressed to the surface of the film, minute unevenness occurs on the surface of the optical film, leading to optical unevenness.

On the other hand, as surface roughness of a protective film, it is preferable that centerline average roughness Ra is 0.005-0.05 micrometers, and it is more preferable that it is 0.01-0.03 micrometer. Surface roughness can be measured using a contact surface roughness meter.

Thus, the protective film which is preferably used in the present invention having a good fish eye level is, for example, a foreign material, a gel or the like using a polymer filter having a fine opening of 10 μm or less after thermal melting of a raw material resin when producing a film. It can manufacture by changing a manufacturing method of a film, such as filtering.

As commercially available polyolefin-based protective film, PP-type PT manufactured by Shin-Etsu Film Co., Ltd., Dorepan BO-2400 and YR12 type manufactured by Toray Industries, Doretec # 7332 by Toray Film Processing, Alpan E200 manufactured by Oji Seishi 6221SC-30 by Sekisui Chemical Industries, Inc., PAC-3 by Sanken Chemical Co., Ltd., etc. other than a series etc. are mentioned, It is not limited to these.

On the other hand, as an adhesive which comprises the adhesive layer which can be formed in one surface of a protective film, the adhesive for re-peeling normally used (acrylic-type, rubber type, synthetic rubber type etc.) can be used without a restriction | limiting in particular. Especially, the acrylic adhesive which is excellent in adhesiveness, workability, durability, etc. and which is easy to control adhesive force by a composition is preferable. On the other hand, it is preferable that the adhesion layer is bridge | crosslinked by the crosslinking agent.

Moreover, a tackifier, a plasticizer, a filler, antioxidant, a ultraviolet absorber, a silane coupling agent, etc. can also be used suitably for the said adhesive as needed.

The formation method of an adhesion layer is not restrict | limited, The method of apply | coating an adhesive to a silicone film which carried out the silicone process, and after drying, the method of transferring to a protective film (transcription method), the method of apply | coating and drying an adhesive composition directly to a protective film ( Direct method), a method by co-extrusion, etc. are mentioned.

Although the thickness of an adhesion layer is not specifically limited, About 3-100 micrometers is preferable, and about 5-40 micrometers is more preferable.

On the other hand, it is preferable to form a conductive layer in the surface on the opposite side to the surface in which the adhesion layer of the said protective film is formed.

The conductive layer is formed by blending an antistatic agent such as a surfactant, conductive carbon, and metal powder to a commonly used polymer such as polyester to form a transparent base film, and applying a surfactant or a conductive resin onto the transparent base film. And the method of drying, and the method of apply | coating, vapor-depositing, or plating a conductive substance, such as a metal and a conductive metal oxide, on a protective film.

The thickness of the conductive layer is not particularly limited, but is preferably about 0.01 to 1 μm, particularly preferably about 0.03 to 0.8 μm. If the thickness of the conductive layer is smaller than 0.01 mu m, the antistatic effect and the static electricity removing effect are insufficient, and if the thickness of the conductive layer is thicker than 1 mu m, the light transmittance is lowered, which is not preferable.

<Optical film roll>

The optical film roll of this invention is laminated | stacked and wound the optical film and protective film containing the above-mentioned cyclic olefin resin.

Here, in order to laminate | stack an optical film and a protective film, the method etc. which pinch | bond and bond an optical film and a protective film between the mirror surface roll whose rotation speed was controlled so that it may become a fixed tension | tensile_strength, and the rubber roll up and down by air are used preferably.

In order to prevent winding shift, it is a preferable method as a method of winding while preventing the shift of both ends of a film using an edge position control system (EPC) etc.

<< polarizing plate >>

The polarizing plate of this invention is the water-based adhesive agent, polar group containing adhesive agent, photocurable adhesive agent, etc. which contain the aqueous solution which mainly made PVA resin the optical film of this invention which is a viewing angle compensation film on at least one surface of the polarizer containing a PVA system film etc. It can be manufactured by bonding using, bonding and heating or exposing it as needed, and pressing together to bond (stack) the polarizer and the viewing angle compensation film.

<< liquid crystal panel >>

The liquid crystal panel of this invention can be manufactured by bonding the polarizing plate of this invention to at least one surface of the liquid crystal display element by which a liquid crystal is clamped between two glass substrates, and bonding (laminating) a liquid crystal display element and a polarizing plate. At this time, a polarizing plate is used for both surfaces of a glass substrate.

<Example>

Hereinafter, although the specific Example of this invention is described, this invention is not limited to these Examples. In addition, below, "part" and "%" mean "weight part" and "weight%" unless there is particular notice.

In addition, in the following Examples, glass transition temperature, saturation absorption factor, the point defect of a protective film, total light transmittance, haze, in-plane phase difference of transmitted light, the transmittance | permeability and polarization degree of a polarizing plate were measured by the following method.

[Glass Transition Temperature (Tg)]

Using a differential scanning calorimeter (DSC) manufactured by Seiko Instruments Co., Ltd., the glass transition temperature was measured under a condition that the temperature increase rate was 20 ° C / min in a nitrogen atmosphere.

[Saturated Absorption Rate]

Based on ASTM D570, after immersing a sample in 23 degreeC water for 1 week, the weight change of the sample before and after immersion was measured, and the saturated water absorption was calculated | required from the value.

[Fish eye, point defect measurement]

The protective film or the optical film was wound up to 10 m 2, placed on black paper, and the shaking of the reflected light was confirmed under a fluorescent lamp of 100 w. The part where the reflected light shakes was counted as the point defect of the fish-eye optical film of a protective film. Thereafter, the film was subjected to microscopic observation 50 times to count the number of fish eyes or point defects of 30 µm or more.

The same was true of observation of the point defect of the roll-shaped optical film.

[Total light transmittance, haze]

The total light transmittance and the haze were measured using a haze meter "HM-150 type" manufactured by Murakami Color Research Institute.

[In-plane Phase Difference (R0) of Transmitted Light]

Using "KOBRA-21ADH" manufactured by Oji Keisoku Kiki Co., Ltd., the in-plane retardation R0 when light was incident perpendicularly to the film was measured at a wavelength of 550 nm.

[Transmittance and Polarization Degree of Polarizing Plate]

The transmittance and polarization degree of the polarizing plate were measured using "RETS" manufactured by Otsuka Denshi Co., Ltd. The measurement wavelength was 550 nm.

[Film thickness distribution]

It measured in the film longitudinal direction using the film thickness distribution measuring apparatus (MOCON).

<Manufacture example 1>

250 parts of distilled water was put into a reaction container, 90 parts of butyl acrylate, 8 parts of 2-hydroxyethyl methacrylate, 2 parts of divinylbenzene, and 0.1 part of potassium oleate were added, and this system was made into polytetrafluoro. The mixture was stirred and dispersed by stirring blades made of ethylene (Teflon®). Then, after nitrogen-substituting this reaction container, this system was heated up to 50 degreeC, 0.2 part of potassium persulfate was added, and superposition | polymerization was started. After 2 hours from the start of the polymerization, 0.1 part of potassium persulfate was further added to the polymerization reaction system, the system was heated to 80 ° C, and the polymer dispersion was continued for 1 hour.

Subsequently, the polymer dispersion liquid was concentrated until the solid content concentration became 70% using the evaporator, and the water-based adhesive (pressure-sensitive adhesive which has a polar group) which consists of the aqueous dispersion of an acrylic ester polymer was obtained.

The number average molecular weight (Mn) in terms of polystyrene was determined by gel permeation chromatography (GPC, solvent: tetrahydrofuran) on the acrylic ester polymer constituting the aqueous adhesive (hereinafter referred to as "water-based adhesive A"). And as a result of measuring the weight average molecular weight (Mw), the number average molecular weight (Mn) was 69,000 and the weight average molecular weight (Mw) was 135,000.

Moreover, it was 1.2 dl / g when the intrinsic viscosity ((eta) h) was measured in the chloroform of 30 _degreeC with respect to the water-based adhesive A.

Example 1

As cyclic olefin resin, norbornene-type resin (JSR Corporation | KK make: brand name "ARTON D4531", glass transition temperature 130 degreeC) was used. The raw material was dehumidified and dried under nitrogen at a drying temperature of 100 ° C., guided by an extruder (GM-65 manufactured by GM Engineering Co., Ltd.) and melted at 260 ° C., quantitatively fed using a gear pump, and a 5 μm leaf disc filter. The foreign matter was removed using, and extrusion was performed from the T die heated by the aluminum casting heater set to 250 degreeC. The opening of the T die at this time was 0.5 mm, and the distance between the T die exit and the crimping point of the film of the cooling roll was 65 mm, and was crimped to a 250 mm Φ cooling roll. The temperature of the cooling roll was 120 degreeC, and 250 mmΦ cooling rolls 2 were provided in the downstream side, and 250 mmΦ peeling roll was further provided in the downstream side. The temperature of each roll was 115 degreeC and 110 degreeC, the film of 100 micrometers thickness was peeled from the peeling roll at the film surface temperature of 108 degreeC, and the norbornene-type resin film was obtained.

The norbornene-based resin film was bonded to the protective film while being pulled out at a tension of 4 kgf to obtain an optical film roll of 2000 m in length (hereinafter also referred to as "optical film roll (a-1)"). Bonding was carried out by passing a transparent film and a protective film between a masking roll made of a mirror roll having a surface roughness of 0.1 S and a rubber roll coated with a pair of urethane rubbers 10 mm.

The protective film used at this time was a 30-micrometer-thick protective film (Toretec # 7332) by Toray Film Processing manufacture, and the number of fisheye of the protective film at this time was 0.5 piece / m <2>.

In addition, the center line surface roughness of the protective film at this time was 0.0006 micrometer.

It was 0.3 piece / m <2> when the number of phase defects of the optical film after peeling a protective film was confirmed.

In addition, the total light transmittance of the said optical film roll (a-1) was 93%, and haze was 0.2%.

Comparative Example 1

After melting the resin in the same manner as in Example 1 to obtain a norbornene-based resin film, an optical film roll having a length of 2,000 m while bonding with a protective film using the same mirror masking roll and rubber roll as in Example 1 (b- 1) was obtained. The commercially available protective film used was a polyethylene system having a thickness of 30 µm, and the number of fish eyes was 6.5 pieces / m 2. The center line surface roughness of the protective film at this time was 0.008 micrometer.

It was 5.5 pieces / m <2> when the number of the phase defects of the optical film after peeling a protective film was confirmed.

In addition, the total light transmittance of the said optical film roll (b-1) was 93%, and haze was 0.3%.

Comparative Example 2

After melting resin in the same manner as in Example 1 to obtain a norbornene-based resin film, an optical film roll (c-1) having a length of 2,000 m was obtained while bonding a protective film in the same manner as in Example 1. The protective film used at this time was a commercially available polyethylene-based protective film having a thickness of 30 µm, and although the number of the point defects thereof was 5 pieces / m 2, the center line surface roughness was 0.025 µm because the surface had scratches.

It was 4.5 pieces / m <2> when the number of point defects of the optical film after peeling a protective film was confirmed.

In addition, the total light transmittance of the said optical film roll (c-1) was 93%, and haze was 0.3%.

The above results are shown in Table 1.

Example 2

After using the optical film roll (a-1) obtained in Example 1, it extended | stretched 1.2 times using the roll nip longitudinal uniaxial stretching machine at 130 degreeC, and extended | stretched by 1.4 times using the tenter-type horizontal stretching machine at 130 degreeC. To obtain a stretched optical film roll (a-2) having a thickness of 70 μm. The phase difference (R0) in the film surface of the phase difference of the said optical film roll (a-2) was 60 nm. Moreover, the total light transmittance of the said optical film roll (a-2) was 93%, and haze was 0.1%.

Moreover, it was 0.1 piece / m <2> when the number of point defects of the said optical film roll (a-2) was confirmed.

Comparative Example 3

Except having used the optical film roll (b-1), it carried out similarly to Example 2, and obtained the stretched optical film roll (b-2). Retardation (R0) in the film surface of the phase difference of this film was 63 nm. Moreover, total light transmittance was 93% and haze was 0.2%.

Moreover, it was 3.5 pieces / m <2> when the number of point defects of the said optical film roll (b-2) was confirmed.

Example 3

The 50-micrometer-thick polyvinyl alcohol film was uniaxially stretched by 4 times for about 5 minutes, immersing in a 40 degreeC bath containing 5 g of iodine, 250 g of potassium iodide, 10 g of boric acid, and 1,000 g of water, and obtained the polarizing film. On the surface of this polarizing film, the optical film roll (a-1) manufactured in Example 1 and the optical film roll (a-1) manufactured in Example 2 were used for the polarizing film, respectively, using the water-based adhesive obtained in manufacture example 1. It adhere | attached continuously by one side to each other, and obtained the polarizing plate (a). As a result of measuring the transmittance | permeability and polarization degree of this polarizing plate (a), it was 43% and 99.99%, respectively. In addition, when the polarizing plate (a) was made into two cross nicol states and irradiated with a backlight having a luminance of 10,000 cd from one side, no light leakage due to a point defect was observed even when observed from the other side.

[Comparative Example 4]

A polarizing plate (b) was obtained in the same manner as in Example 3 except that the optical film rolls (b-2) and (c-1) were used. As a result of measuring the transmittance | permeability and polarization degree of this polarizing plate (b), it was 42% and 99.87%, respectively. In addition, when the said polarizing plate (b) was made into two cross nicol states so that an optical film roll (b-2) may become inward, and it irradiated with the backlight of 10,000 cd of luminance from one side, when it observed from the other side, it was a point defect. Light leakage attributable to was found to be 3.0 / m 2.

Even if the optical film roll in which the optical film and the protective film of this invention are laminated | stacked is stored for a long time, since there are few fish eye in a protective film, minute unevenness | corrugation does not generate | occur | produce on the optical film surface and an optical nonuniformity does not arise. Therefore, the optical film obtained from the optical film roll of this invention is a mobile phone, a digital information terminal, a wireless pager, navigation, a vehicle-mounted liquid crystal display, a liquid crystal monitor, a liquid crystal television, a light control panel, a display for OA apparatuses, AV equipment, for example. It can be used for various liquid crystal display elements such as a display for display, an electroluminescent display element or a touch panel. It is also useful as a wave plate used for recording / reproducing apparatus of optical discs such as CD, CD-R, MD, MO, DVD.

Claims (5)

The optical film roll formed by laminating | stacking the optical film and protective film containing cyclic olefin resin, WHEREIN: The optical film roll whose number of fish eyes of 30 micrometers or more in diameter in a said protective film is 5 pieces / m <2> or less. The optical film roll of Claim 1 whose cyclic olefin resin is a (co) polymer of the compound represented by following General formula (1). <Formula 1>

(In the formula 1, R ¹ to R ⁴ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or monovalent other organic group, and each may be the same or different, and any of R ¹ to R ⁴ Two of may combine with each other to form a monocyclic or polycyclic structure, m is 0 or a positive integer, p is 0 or a positive integer) The optical film roll of claim 1 wherein the centerline average roughness Ra of the protective film is 0.005 to 0.05 μm. The optical film roll of Claim 1 in which a protective film contains polyolefin crab resin. The optical film containing a cyclic olefin resin film, and the number of fish eyes of 30 micrometers or more in diameter are piled up and wound up and wound, The manufacturing method of the optical film roll characterized by the above-mentioned.