KR20080031803A - Process for producing an optical film - Google Patents

Abstract

An optical film manufacturing method is provided to secure stable phase difference or an optical axis if a film is stretched, to reduce optical non-uniformity of an optical film, and to obtain favorable yield rate of the film and high transparency by reducing a haze value. An optical film manufacturing method transports resin pellets to an extruder by inert gas with oxygen concentration below 10 ppm, and melts and extrudes the pellets. Resin pellets filled into a container are transported to a dryer and then delivered from the dryer to the extruder by inert gas with oxygen concentration below 10 ppm. The inert gas is nitrogen. The resin pellet is made of cyclic olefin resin having structure unit derived from compounds.

Description

Production method of optical film {PROCESS FOR PRODUCING AN OPTICAL FILM}

The present invention relates to a method for producing an optical film without optical nonuniformity.

The optical film is required to be excellent in optical properties such as transparency, and at the same time, it is important that the film is homogeneous and the optical nonuniformity is small. When resin used for film forming deteriorates, a gel will generate | occur | produce in resin, a point defect etc. will generate | occur | produce on the surface of the obtained film, and it will become a cause of optical nonuniformity. Therefore, as a method of preventing the deterioration of the resin, a method of preserving the resin such as a method of using a container having a specific gas permeation amount and foreign matter amount or a method of coexisting an oxygen detector and / or a water detector in a sealed container has been proposed. (See Patent Documents 1 and 2 below). However, in recent years, it is required to manufacture a wide film having a width of 1 m or more with a good yield due to the enlargement of a liquid crystal panel, and the like, as a method for preventing optical unevenness over a wide range when forming such a wide optical film. The method was insufficient.

[Patent Document 1] Japanese Patent Application Laid-Open No. 7-206998

[Patent Document 2] Japanese Patent Application Laid-Open No. 2001-192458

This invention makes it a subject to provide the manufacturing method of the optical film which optical nonuniformity does not produce over a wide range.

The present invention relates to a method for producing an optical film, wherein the resin pellets are transported to an extruder using an inert gas having an oxygen concentration of 10 ppm or less as a medium, and the pellets are melt-extruded.

In this invention, it is preferable to transport the resin pellet enclosed in the container to a drier, and to transport it to the extruder using the inert gas of 10 ppm or less of oxygen concentration as a medium from the drier. In this case, it is preferable to transport the resin pellets enclosed in the container to a drier using an inert gas having an oxygen concentration of 10 ppm or less as a medium.

In the present invention, the inert gas is preferably nitrogen.

In this invention, it is preferable that a resin pellet is a pellet of cyclic olefin resin which has a structural unit derived from the compound represented by following formula (1).

(In formula 1, R <^1> -R <^4> is a hydrogen atom, a halogen atom, a C1-C30 hydrocarbon group, or other monovalent organic group, respectively, may be same or different, Moreover, R <^1> -R <^4> Any two may be bonded to each other to form a monocyclic or polycyclic structure, m is 0 or a positive integer, and p is 0 or a positive integer)

This invention may be the manufacturing method of the optical film formed by extending | stretching the said optical film further.

According to this invention, even if it is a wide film, the manufacturing method of the optical film without optical nonuniformity can be provided. Moreover, when an optical film is a film which extended | stretched, it can use suitably as a film which is optically nonuniform in which retardation and an optical axis are stable. The optical film according to the present invention has a small optical nonuniformity, a good yield of the film, a small haze value in the stretched film, and excellent transparency, and a large liquid crystal display using the same has no deformation or nonuniformity in the whole surface. Can achieve high performance.

<< optical film >>

<Resin>

As resin used for this invention, the light transmittance in film form is 70% or more, Preferably it is 85% or more. Specifically, it has high transparency such as a transparent epoxy resin, a polyester resin, a polycarbonate resin, a polyether sulfone resin, a polyarylate resin, a cyclic olefin resin, a polyphenylene ether resin, an organic siloxane resin, and is excellent. Resin which has heat resistance is mentioned as a preferable thing. Among these, cyclic olefin resins, polyphenylene resins, and organosiloxane resins are preferable in that the specific member obtained because of excellent transparency and heat resistance and low moisture absorption (water) is less likely to be absorbed (water). Especially preferably, cyclic olefin resin which has a structural unit derived from the compound represented by the said General formula (1) is mentioned.

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) A saturated copolymer of a specific monomer represented by the formula (1) and an unsaturated double bond-containing compound.

(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 of m = 1 and 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 - is (CH _{2) n} polar group of monomers represented by COOR is, has 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, in particular a methyl group, and in particular, the alkyl group is It is preferable that the specific polar group represented by-(CH ₂ ) _n COOR is bonded to the same carbon atom as the carbon atom to which it is bonded, in that the hygroscopicity of the obtained cyclic olefin resin can be lowered.

<Copolymerizable monomer>

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

As carbon number of cycloolefin, 4-20 are preferable, More preferably, it is 5-12. 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 catalytic activity, 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.

Specific examples of the component (b) include 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 And the compound described in Japanese Patent Laid-Open Publication No. Hei 1 32626, page 8, upper right column 18th to page 8, lower right column 3, such as methylalumoxane and LiH.

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 the component (a) and the component (c) is in the 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, hexamethylenedibromide, Compounds such as halogenated alkanes and aryl halides such as chlorobenzene, chloroform and tetrachloroethylene; saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, iso-butyl acetate, methyl propionate and dimethoxyethane, and dibutyl Ethers such as ether, tetrahydrofuran, dimethoxyethane and the like, and the like can 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-non-porous A specific monomer may also 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 liquid 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.

As described above, 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, Especially preferably, it is 99% 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 against heat and light, and when used as the wavelength plate of the present invention, 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 ₂ ClCOOH, zeolite and activated clay, and Bronsted 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 ≦ vanadium compounds represented by (a + b) ≤ 3, 0 ≤ c ≤ 4, 0 ≤ d ≤ 4, and 3 ≤ (c + d) ≤ 4], or their electron donating adducts.

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, molecular weight adjustment 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 Vinylcyclohexane monomers such as vinylcyclohexene monomers such as 2-methyl-4-isopropenylcyclohexene, 4-vinylcyclohexane, and 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 As there may be mentioned heptene, 4-isopropoxy-phenyl cycloheptene, etc. of the vinyl monomer cycloheptyl butene, 4-vinyl-cycloheptane, 4-cycloheptane isopropenyl vinyl chloride during heptane-based monomers and the like. 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.

Moreover, the alternating copolymer of (7) the said specific monomer and acrylate can also be used as cyclic olefin resin of this invention.

<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 radical polymerization initiator that generates a free radical 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 to each other.

The preferred molecular weight of the cyclic olefin resin used in the present invention is 0.2 to 5 dl / g, more preferably 0.3 to 3 dl / g, particularly preferably 0.4 to 1.5 dl / g in intrinsic viscosity [η] _inh , The number average molecular weight (Mn) in terms of polystyrene dissolved in tetrahydrofuran and measured by gel permeation chromatography (GPC) is 8,000 to 100,000, more preferably 10,000 to 80,000, particularly preferably 12,000 to 50,000, and 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. Moreover, molecular weight distribution (Mn / Mw) becomes like this. Preferably it is 2.0-4.0, More preferably, it is 2.5-3.7, More preferably, it is 2.8-3.5.

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, since a shaping | molding process becomes difficult and it is necessary to raise the heating temperature at the time of shaping | molding process, the possibility of resin deterioration by heat increases.

In the above cyclic olefin resin, the specific hydrocarbon described in Unexamined-Japanese-Patent No. 9-221577 and Unexamined-Japanese-Patent No. 10-287732 in the range which does not impair the effect of this invention, for example. Or a known thermoplastic resin, thermoplastic elastomer, rubbery polymer, organic fine particles, inorganic fine particles, or the like.

Moreover, additives, such as well-known antioxidant and ultraviolet absorber, can be added to the cyclic olefin resin used for 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, one or more compounds selected from the group consisting of the following phenolic compounds, thiol compounds, sulfide compounds, disulfide compounds, and phosphorus compounds are 0.01 to 100 parts by weight of the cyclic olefin resin of the present invention. By adding 10 parts by weight, 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-hydrocinnamamide), 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 and the like. There All. 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'-thiodiprop Cypionate, distearyl 3,3'- thiodipropionate, pentaerythryl tetrakis (3-laurylthiopropionate), ditridecyl 3,3'- thiodipropionate, etc. are mentioned. Can be.

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, preferably 0.05 to 2 parts by weight of an oxanilide compound such as 2-ethyloxanide and 2-ethyl-2'-ethoxyoxanide, based on 100 parts by weight of the cyclic olefin resin By addition, light resistance can be improved.

In addition, in the case of molding into a film or the like by melt extrusion, an oxidizing agent may be added to the cyclic olefin resin according to the present invention in order to prevent the resin from thermally deteriorating due to the heat history during melt extrusion.

As a specific example of the said antioxidant, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- butyl- 4-hydroxybenzyl) benzene, N, N'-hexa Methylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnaamide), tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanate, tris (2,4 Although -di-t-butylphenyl) phosphite etc. are mentioned, this invention is not limited to these, In addition, also in these, it may be inappropriate depending on Tg of cyclic olefin resin to melt-extrude. 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 addition amount of antioxidant is less than 0.01 weight part, a gel will generate | occur | produce easily in resin at the time of extrusion processing, and it may be recognized as a defect on the obtained film by this, and it is unpreferable. On the other hand, when the amount of the additive exceeds 5 parts by weight, it may cause the generation of slime at the time of processing, and this slime is not preferable because it causes a die line, a fish eye on the film, soot 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>

The molding method of the optical film of the present invention is a melt extrusion method, wherein resin pellets are transported to an extruder using an inert gas having an oxygen concentration of 10 ppm or less as a medium, and the pellets are melt-extruded. Specifically, the resin pellets enclosed in the container are transported to a drier, and the drier is transported to the extruder using an inert gas having an oxygen concentration of 10 ppm or less, preferably 8 ppm or less, more preferably 6 ppm or less as a medium. It is desirable to. Specifically, as shown in FIG. 1, the resin pellets enclosed in the container are transported to a drier using an inert gas having an oxygen concentration of 10 ppm or less as a medium, and the drying process is performed, followed by filling in the drier by preceding transportation. It is preferable to transfer the pellets to the extruder using the inert gas.

The container may be one having a tank for encapsulating the pellet, an extraction tube for extracting the pellet, and a facility for extracting the pellet in the upper portion thereof. It is necessary to enclose the pellet in a clean state inside the container, and also to shield the pellet so as to prevent intrusion of foreign matter from the outside after the encapsulation.

The dryer is generally used at a suitable temperature of Tg or less of the resin for the purpose of preliminarily removing moisture, gas (oxygen, etc.), residual solvent, and the like contained in the resin before inserting the resin pellet into the extruder. It is used to perform drying. Preferably, an inert gas circulation type dryer or a vacuum dryer is used.

The resin pellets are usually transported to the dryer through a suction hopper (hereinafter simply referred to as a "hopper") provided between the container and the dryer. At the time of transport, the hopper is reduced in pressure, and the resin pellets are conveyed to the dryer by sending the inert gas from the valve attached to the container. Moreover, in order to suppress moisture absorption and oxygen absorption in a hopper, it is also preferable to use the vacuum hopper which can seal a hopper with inert gas, such as nitrogen and argon, or can keep it at reduced pressure.

The dried resin pellets are transported to the extruder through a hopper installed on top of the extruder. As in the transportation to the dryer, at the time of transportation, the hopper is reduced in pressure, and the inert gas and the resin pellets filled in the dryer are transported to the dryer. In addition, transport can also be carried out while introducing an inert gas from the outside.

As an inert gas used for this invention, if it is a gas which does not react with a resin pellet, it will not specifically limit, Although nitrogen, carbon dioxide, argon, etc. are mentioned, Nitrogen is used preferably. In addition, although the flow rate of nitrogen gas at the time of using for the transportation of resin pellets also depends on the size of a dryer and an extruder, it is 100-800 l / min normally, Preferably it is 120-600 l / min.

The method for obtaining the cyclic olefin resin film by the melt extrusion method is not particularly limited, and a known method can be applied. 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 the mirror surface roll surface, and then cooling and peeling to form a sheet may be 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, by attaching a film to the mirror surface roll side from the charging electrode arrange | positioned so that it may oppose each other to the mirror surface roll below the discharge port of die | dye at the position of the both ends of the film discharged, in order to improve the surface property of a film without giving optical deformation. The method and the like are also preferable methods.

As the extruder, any one of single screw, twin screw, planetary type, co-kneader and the like can be used, but preferably, a single screw extruder is used. Examples of the screw shape of the extruder include a vent type, a sub-flight type, a tip less-magnet type, a full flight type, a large compression ratio, a small one, a slow compression of a long compression section, a short compression compression type, and the like. However, gels tend to be generated in the resin due to the mixing of oxygen and the shear heat generation inside the extruder. Since this gel causes a point defect or soot called fish eye in the film, it is preferable that it is of a flight shape / compression type that can suppress dissolution of oxygen and can suppress shear heat generation, and a preferable compression ratio is 1.5 to 4.5. And particularly preferably 1.8 to 3.6. As the gear pump used for the metering of the resin, both an internal lubrication type and an external lubrication type can be used.

As a filter used for filtration of a foreign material, a leaf disc type, a candle filter type, a leaf type, a screen mesh, etc. are mentioned. 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, and in order to maintain film uniformity in the die, it is essential that the pressure distribution inside the die near the die outlet 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, draw air or the like into the gap between the attachment parts, or cause soot, It is not desirable because it can cause. The discharge port of the die is preferably provided with a coating such as an ultrahard 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 the soot dregs and the like can be prevented from being mixed in the transparent resin sheet obtained, and the die line can be prevented from occurring.

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 the width direction of an acceptable roll is preferably within 2 degreeC, More preferably, it is within 1 degreeC. .

It is preferable to use a seamless endless belt as the metal belt used for the single-sided belt type device and the sleeve type take-out device. 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, which may cause scratches on the belt, which is not preferable. On the other hand, when it is thicker than 0.4 mm, since it does not follow the film and deform | transforms at the time of processing, it is unpreferable.

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

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 by 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 degrees C or less.

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.

At this time, it is preferable to make the circumferential speed of a mirror surface roll and a metal belt approach. As a preferable range, when the circumferential speed of a mirror surface roll is set to 1.00, the circumferential speed of a metal belt is 0.95-1.05, Especially preferably, it is 0.99-1.01.

Furthermore, as conditions at the time of film peeling, a peeling temperature _{T t} (℃), when a peeling stress T _F (MPa), respectively, _{Tg-30 ℃ ≤T t ≤Tg +} 5 ℃, 0.01 MPa≤T F range of ≤5 MPa Is preferably.

Here, the temperature of the mirror surface roll which is a cooling roll is Tg-80-Tg + 10 degreeC normally, Preferably it is Tg-60-Tg-2 degreeC.

The horizontal portion of the flow path of the die of the present invention collides with the tip portion of the outlet of the die, which is called a die land. The length of the die land is 10 to 50 mm, preferably 11 to 40 mm.

<Film stretching processing>

The optical film of this invention can also extend | stretch the optical film obtained by making it 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. At this time, the crossing angle of the two stretching axes for controlling the shape of the refractive index ellipsoid of the film after stretching is not particularly limited because it is determined according to desired characteristics, but is usually in the range of 120 to 60 degrees. 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 the refractive 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. If the draw ratio is 10 times or more, the control of the phase difference may be difficult.

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. % Or less, Especially preferably, it is 0.5% or less.

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

In order to make a dimensional shrinkage rate into the said range, in addition to selection of monomers A and B which are raw materials of resin of this invention, it can control by a casting method or an extending 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 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 the retardation film can be further thinned by making the optical film before stretching thin or by increasing the draw ratio relatively.

<Film characteristics>

The optical film (melt-extruded film, stretched film) of the present invention obtained as described above has a point defect of 30 µm or more in diameter on the surface of the film of 3 / m ² or less, preferably 1 / m ² or less. do. The point defect refers to a point or substantially circular irregularities existing on the surface of the film, and one of the causes of the defects includes a foreign substance such as a gel present in the resin. The said point defect becomes a big cause of optical nonuniformity.

Moreover, since the stretched optical film of this invention is excellent in surface smoothness, the haze value in 3 mm of thickness measured according to ASTMD1003 is 1% or less, Preferably it is 0.8% or less.

Moreover, average roughness Ra of a film is 0.2 micrometer or less, Preferably it is 0.15 micrometer or less, More preferably, it is 0.1 micrometer or less.

<< polarizing plate >>

The polarizing plate of this invention uses the water-based adhesive agent, polar group containing adhesive agent, a photocurable adhesive agent, etc. which contain the aqueous solution which mainly uses PVA resin for the optical film of this invention on at least one surface of the polarizer containing a PVA system film etc. It can be manufactured by bonding together, and heating or exposing this as needed, crimping | bonding, and bonding (laminating) a polarizer and an optical film as needed.

<< 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.

<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 example, various evaluation was 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.

[Point Defect Measurement]

The optical film was wound up 10 m ² and placed on black paper, and the shaking of the reflected light was confirmed under a fluorescent lamp of 100 w. The part which marked the place where the reflection light shakes was a point defect. Thereafter, the surface of the film was observed with a 50x optical microscope, and the number of point defects having a diameter of 30 µm or more was counted.

[Total light transmittance, haze]

The total light transmittance and the haze were measured using a haze meter "HM-150" manufactured by Murakami Shikisai Kijutsu Co., Ltd.

[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>

94.8 parts of butyl acrylate, 5 parts of acrylic acid, and 0.2 parts of 2-hydroxyethyl methacrylate, and the weight average molecular weight (Mw) of 1.2 million, the ratio of the weight average molecular weight and the number average molecular weight (Mn) (Mw / Mn) of 3.9 Toluene was added to the ethyl acetate solution of the acrylic polymer and diluted to obtain a 13% toluene solution of the acrylic polymer, and 2.0 parts of an isocyanate crosslinking agent (Colonate L (manufactured by Nippon Polyurethane Co., Ltd.)) was added thereto, followed by stirring. After apply | coating and drying in two steps of 100 degreeC * 5 minutes, 60 degreeC * 5 minutes, it prevents foaming, and further, the light peeling type release film is temporarily fixed to the adhesive surface, and the adhesive thickness (average value) after drying A non-support film of 25 μm was prepared.

Example 1

As a resin, a resin pellet enclosed in an 800 kg container using cyclic olefin resin (manufactured by JSR Co., Ltd .: trade name "ARTON D4531", glass transition temperature of 130 ° C) was subjected to 200 l / min of nitrogen at an oxygen concentration of 0.1 ppm. It transported to the nitrogen circulation type | mold dryer (made by Nissuga Co., Ltd. model number NS-200), and dehumidified drying for 180 minutes was performed at 100 degreeC of drying temperature in nitrogen atmosphere. Thereafter, the resin was introduced to an extruder (GM-manufactured by GM Engineering: GM-90) using 200 l / min of nitrogen at an oxygen concentration of 0.1 ppm, melted at 260 ° C, and the liquid was fed in a fixed amount using a gear pump, The foreign matter was removed using a 5 μm leaf disc filter, and extrusion was performed from a T die heated by an aluminum casting heater set at 250 ° C. The opening of the T die at this time was 0.5 mm, the distance between the T die exit and the crimping point of the film of the cooling roll was 65 mm, and it crimp | bonded to the 250 mm diameter cooling roll. The temperature of the cooling roll was 120 degreeC, The 250 mm diameter cooling roll 2 was provided in the downstream side, and the 250 mm diameter 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 in thickness was peeled from the peeling roll at the film surface temperature of 108 degreeC, and the norbornene-type resin film was obtained.

As a result of confirming the number of point defects of the obtained optical film, it was 0.3 piece / m <^2> . Moreover, the total light transmittance of the said optical film was 93%, and haze was 0.2%.

Comparative Example 1

An optical film (b-1) was obtained in the same manner as in Example 1 except that the transport from the container to the dryer and the transport from the dryer to the extruder were all performed in an air atmosphere. It was 3.2 pieces / m <^{2> as a} result of confirming the number of point defects of an optical film. In addition, the total light transmittance of the said optical film roll (b-1) was 93%, and haze was 0.3%.

Example 2

Using the optical film (a-1) obtained in Example 1, stretching was carried out 1.2 times using a roll nip longitudinal uniaxial stretching machine at 130 ° C., and then stretched 1.4 times using a tenter-type transverse stretching machine at 130 ° C. A stretched optical film (a-2) of 70 mu m was obtained. Retardation (R0) in the film surface of the phase difference of the said optical film (a-2) was 60 nm. In addition, the total light transmittance of the said optical film (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 (a-2) was confirmed.

Comparative Example 2

Except having used the optical film (b-1), it carried out similarly to Example 2, and obtained the stretched optical film (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 (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 1000 g of water, and obtained the polarizing film. On the surface of this polarizing film, the optical film (a-1) manufactured in Example 1 and the optical film (a-2) manufactured in Example 2 were used for each side of the polarizing film using the adhesive obtained by the manufacture example 1, respectively. It was continuously bonded 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 said polarizing plate (a) was made into two cross nicol states, and it irradiated with the back light of luminance 10,000 cd from one side, even if it observed from the other side, the light leakage resulting from a point defect was not confirmed at all.

Comparative Example 3

A polarizing plate (b) was obtained in the same manner as in Example 3 except that the optical films (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. Moreover, 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 brightness 10,000 cd, from one side, it is a point defect. The light leakage attributable to was found to be 3.0 / m ² .

The optical film of this invention does not generate a point defect on the surface of an optical film, and does not produce an optical nonuniformity. 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.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the resin pellet transport route used preferably in the manufacturing method of the optical film of this invention.

Claims (6)

A resin pellet is transported to an extruder using an inert gas of 10 ppm or less of oxygen concentration as a medium, and the said pellet is melt-extruded, The manufacturing method of the optical film characterized by the above-mentioned. The method for producing an optical film according to claim 1, wherein the resin pellets enclosed in the container are transported to a drier, and the extruder is transported from the drier to an extruder using an inert gas having an oxygen concentration of 10 ppm or less as a medium. The method for producing an optical film according to claim 2, wherein the resin pellet enclosed in the container is transported to a drier using an inert gas having an oxygen concentration of 10 ppm or less as a medium. The method for producing an optical film according to claim 1, wherein the inert gas is nitrogen. The method for producing an optical film according to claim 1, wherein the resin pellet is a pellet of a cyclic olefin resin having a structural unit derived from a compound represented by the following formula (1). <Formula 1>

(In the formula 1, R ¹ to R ⁴ may be a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or monovalent other organic group, the same or different, R ¹ to any of the R ⁴ Two may combine with each other to form a monocyclic or polycyclic structure, m is 0 or a positive integer, and p is 0 or a positive integer) It extends further, The manufacturing method of the optical film of Claim 1 characterized by the above-mentioned.

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