JP2006255892A - Film processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a homogenous stretched resin film, which has orientation in its oblique direction, constituted so as to prevent a bowing phenomenon (axial shift phenomenon) most apprehended in oblique stretching, causing no cutting loss, for example, when a retardation film and a polarizing film are laminated so as to form a definite angle and capable of simplifying a process. <P>SOLUTION: In the film processing method for continuously stretching a resin film obliquely in the direction forming an angle of 5-85° with respect to the lateral direction of the resin film, the film at the time of stretching has a temperature distribution in its lateral direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a film processing method capable of forming an obliquely oriented film useful for a retardation plate and the like in a uniform and efficient manner with little film loss.

  Conventionally, as a method of manufacturing an obliquely aligned retardation plate whose orientation axis is inclined with respect to the periphery, the orientation axis is relative to the side from a film uniaxially stretched in the longitudinal (length) direction or the transverse (width) direction. A method of cutting by a method of punching the periphery so as to obtain a predetermined inclination angle is known.

  This obliquely aligned retardation plate is used by adhering to a polarizing plate forming a liquid crystal display device for the purpose of optical compensation such as coloring prevention and viewing angle expansion, and in that case, with respect to the transmission axis of the polarizing plate. It is required that the orientation axis of the retardation plate can be set at various angles, and an obliquely oriented retardation plate in which the inclination angle of the orientation axis is set to an arbitrary angle is required.

  However, in the conventional method of cutting the uniaxially stretched film described above, a cutting loss of, for example, a triangular piece necessarily occurs on both sides, and the cutting loss also increases in the formation of a large size and an oblique alignment phase difference plate having a large inclination angle. In general, there is a problem that the film utilization efficiency, that is, the product yield is poor.

  In order to solve this problem, the tilt angle of the orientation axis can be variously changed, and the obliquely oriented retardation plate can be used efficiently with a high yield of the raw material film without cutting loss, and the number of steps is less than that of the unstretched film. There is a method for producing a stretched film that can be efficiently obtained, and can easily form a continuous body of obliquely aligned retardation plates having a predetermined alignment axis, and can be used for adhesion to a long polarizing plate as it is. Many proposals have been made (see Patent Documents 1 to 3). Specifically, the orientation axis can be tilted by stretching at different lateral or longitudinal feed forces, pulling forces or take-up forces (hereinafter, the stretching method is referred to as “oblique stretching”). Also called).

However, in general, in the above method, it has been extremely difficult to make the physical properties in the width direction of the product film uniform.
That is, since both side edges of the film are gripped by the gripping means in the tenter, the longitudinal shrinkage stress accompanying the transverse stretching is constrained by the gripping means. On the other hand, the central portion of the film tends to move due to the shrinkage stress because the restraining force by the gripping means is relatively weak. If a straight line is drawn in the transverse direction on the film surface before transverse stretching, the straight line is transformed into a concave curve in the film traveling direction. This phenomenon is called Boeing. This bowing phenomenon causes non-uniform physical properties in the width direction of the film, particularly optical characteristics such as orientation angle distribution, mechanical characteristics, humidity expansion coefficient, thermal expansion coefficient, and thermal contraction ratio. In drawing, there is a particular concern about the effect of this bowing phenomenon.
Japanese Patent Laid-Open No. 2000-9912 JP 2002-86554 A JP 2003-342384 A

  The present invention prevents the bowing phenomenon (axial misalignment phenomenon) most concerned with oblique stretching, and when laminating a retardation film and a polarizing film at a certain angle, there is no cutting loss, and the process can be simplified. An object is to provide a homogeneous stretched resin film having an orientation in an oblique direction.

The present invention is a method of continuously stretching a resin film in a direction of 5 to 85 degrees with respect to its width direction, wherein the film during stretching has a temperature distribution in its width direction. Regarding the method.
Here, the temperature distribution of the resin film is preferably a distribution in which the temperature in the central portion in the width direction has a temperature difference of 10 ° C. at the maximum compared to the end portion.
The temperature of the resin film is in the range of Tg-30 ° C. to Tg + 60 ° C. (where Tg is the glass transition temperature of the resin), and the film temperature at the center in the film width direction is the end film. It is preferably 0.5 to 10 ° C. lower than the temperature.
Furthermore, the resin constituting the resin film is preferably cellulose acetate or a cyclic olefin resin.

  According to the present invention, it is possible to prevent the bowing phenomenon that is feared by oblique stretching, and there is no cutting loss when laminating a retardation film and a polarizing film at a certain angle, and the process can be simplified. A homogeneous resin film having an orientation in the direction is obtained.

[resin]
In the present invention, the resin film to be subjected to the oblique stretching treatment is not particularly limited, and a film made of a thermoplastic resin can be used, and an unstretched film is generally used. Incidentally, examples of the resin include cellulose acetate and cyclic olefin resin, polycarbonate, polyester, polysulfone, polyethersulfone, polystyrene, polyolefin, polyvinyl alcohol, polyvinyl chloride, polymethyl methacrylate, polyarylate, polyamide, and the like. Preferably, cellulose acetate and a cyclic olefin resin are used.

Cellulose acetate The cellulose acetate used in the resin film of the present invention is preferably a lower fatty acid ester of cellulose. Lower fatty acid means a fatty acid having 6 or less carbon atoms. The number of carbon atoms is preferably 2 (cellulose acetate), 3 (cellulose propionate) or 4 (cellulose butyrate), particularly preferably cellulose acetate. Further, mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate may be used.

  In the case of cellulose acetate, it is preferable to produce a cellulose acetate film by a solution casting method. In the solution casting method, a film is produced using a solution (dope) in which a polymer is dissolved in an organic solvent. The organic solvent is a solvent selected from ethers having 3 to 12 carbon atoms, ketones having 3 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 6 carbon atoms. It is preferable to contain.

  Examples of the ether having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone. Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. The number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, and most preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of halogen atoms substituted by halogen in the halogenated hydrocarbon is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and more preferably 35 to 65 mol%. More preferably, it is most preferable that it is 40-60 mol%. Methylene chloride is a representative halogenated hydrocarbon. Two or more organic solvents may be mixed and used.

  A polymer solution can be prepared by a general method. The general method means that the treatment is performed at a temperature of 0 ° C. or higher (room temperature or high temperature). The solution can be prepared using a dope preparation method and apparatus in a normal solution casting method. In the case of a general method, it is preferable to use a halogenated hydrocarbon (particularly methylene chloride) as the organic solvent. The amount of the polymer is adjusted so as to be contained by 10 to 40% by weight in the resulting solution. The amount of polymer is more preferably 10 to 30% by weight. Arbitrary additives described later may be added to the organic solvent (main solvent). The solution can be prepared by stirring the polymer and the organic solvent at room temperature (0 to 40 ° C.). High concentration solutions may be stirred under pressure and heating conditions. Specifically, the polymer and the organic solvent are put in a pressure vessel and sealed, and stirred while heating to a temperature not lower than the boiling point of the solvent at normal temperature and in a range where the solvent does not boil. The heating temperature is usually 40 ° C. or higher, preferably 60 to 200 ° C., and more preferably 80 to 110 ° C.

A polymer film is produced from the prepared polymer solution (dope) by solution casting.
The dope is cast on a drum or band, and the solvent is evaporated to form a film. The concentration of the dope before casting is preferably adjusted so that the solid content is 18 to 35% by weight. The surface of the drum or band is preferably finished in a mirror state. The casting and drying methods in the solution casting method are described in JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, and JP-A-62-115035. There is. The dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less. It is preferable to dry the cast material by applying it to the wind for 2 seconds or more. The obtained film can be peeled off from the drum or band, and further dried by high-temperature air whose temperature is successively changed from 100 to 160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting. The solution (dope) prepared according to the present invention satisfies this condition. The thickness of the film to be produced is preferably 40 to 200 μm, and more preferably 50 to 150 μm.

  In addition, a plasticizer can be added to the cellulose acetate film in order to improve mechanical properties or improve the drying speed. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include triethyl o-acetylcitrate (OACTE) and tributyl o-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred. The addition amount of the plasticizer is preferably 0.1 to 25% by weight of the amount of cellulose ester, more preferably 1 to 20% by weight, and most preferably 3 to 15% by weight.

  In addition, a degradation inhibitor (eg, antioxidant, peroxide decomposer, radical inhibitor, metal deactivator, acid scavenger, amine) may be added to the cellulose acetate film. The addition amount of the deterioration preventing agent is preferably 0.01 to 1% by weight of the solution (dope) to be prepared, and more preferably 0.01 to 0.2% by weight. When the addition amount is less than 0.01% by weight, the effect of the deterioration preventing agent is hardly recognized. If the amount added exceeds 1% by weight, bleed-out (bleeding) of the deterioration preventing agent to the film surface may be observed. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (BHT) and tribenzylamine (TBA).

Cyclic Olefin Resin Examples of the cyclic olefin resin used in the resin film of the present invention include the following (co) polymers.
(1) A ring-opening polymer of a specific monomer represented by the following general formula (I).
(2) A ring-opening copolymer of a specific monomer represented by the following general formula (I) and a copolymerizable monomer.
(3) A hydrogenated (co) polymer of the ring-opening (co) polymer of (1) or (2) above.
(4) A (co) polymer obtained by cyclizing the ring-opening (co) polymer of (1) or (2) above by a Friedel-Craft reaction and then hydrogenating it.
(5) A saturated copolymer of a specific monomer represented by the following general formula (I) and an unsaturated double bond-containing compound.
(6) Addition type (co) of one or more monomers selected from a specific monomer represented by the following general formula (I), a vinyl-based cyclic hydrocarbon-based monomer, and a cyclopentadiene-based monomer Polymers and their hydrogenated (co) polymers.
(7) An alternating copolymer of a specific monomer represented by the following general formula (I) and an acrylate.

[Wherein, R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or another monovalent organic group, and may be the same or different. R ¹ and R ² or R ³ and R ⁴ may be combined to form a divalent hydrocarbon group, and R ¹ or R ² and R ³ or R ⁴ are bonded to each other to form a single ring or A polycyclic structure may be formed. m is 0 or a positive integer, and p is 0 or a positive integer. ]

<Specific monomer>
Specific examples of the specific monomer include the following compounds, but the present 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 . 0 ^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-phenyltetracyclo [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,
8-methyl-8- (2,2,2-trifluoroethoxycarbonyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene.
These can be used alone or in combination of two or more.

Among the specific monomers, in general formula (I), R ¹ and R ³ are each a hydrogen atom or a hydrocarbon group having 1 to 10, more preferably 1 to 4, and particularly preferably 1 to 2 carbon atoms. R ² and R ⁴ are a hydrogen atom or a monovalent organic group, and 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, and m is 0 An integer of ˜3, p is an integer of 0 to 3, more preferably m + p = 0 to 4, more preferably 0 to 2, particularly preferably m = 1 and p = 0. The specific monomer in which m = 1 and p = 0 is preferable in that the cyclic olefin resin obtained has a high glass transition temperature and excellent mechanical strength.
Examples of the polar group of the specific monomer include a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, and a cyano group. These polar groups are connected via a linking group such as a methylene group. May be combined. In addition, a hydrocarbon group in which a divalent organic group having a polarity such as a carbonyl group, an ether group, a silyl ether group, a thioether group, or an imino group is bonded as a linking group can also be exemplified. Among these, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group or an allyloxycarbonyl group is preferable, and an alkoxycarbonyl group or an allyloxycarbonyl group is particularly preferable.

Furthermore, the monomer in which at least one of R ² and R ⁴ is a polar group represented by the formula — (CH ₂ ) _n COOR is a material in which the cyclic olefin resin obtained has a high glass transition temperature, a low hygroscopic property, and various materials. It is preferable at the point from which it has the outstanding adhesiveness. In the formula relating 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, and preferably an alkyl group. In addition, n is usually 0 to 5, but the smaller the value of n, the higher the glass transition temperature of the resulting cyclic olefin resin, which is preferable, and the specific monomer having n of 0 is It is preferable in that the synthesis is easy.

In the general formula (I), 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 carbon atoms, particularly a methyl group. In particular, it is preferable that the alkyl group is bonded to the same carbon atom as the carbon atom to which the specific polar group represented by the above formula — (CH ₂ ) _n COOR is bonded. This is preferable in that the hygroscopicity can be lowered.

<Copolymerizable monomer>
Specific examples of the copolymerizable monomer include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene.
The number of carbon atoms of the cycloolefin is preferably 4-20, and more preferably 5-12. These can be used alone or in combination of two or more.
A preferred use range of the specific monomer / copolymerizable monomer is 100/0 to 50/50, more preferably 100/0 to 60/40, in weight ratio.

<Ring-opening polymerization catalyst>
In the present invention, (1) a ring-opening polymer of a specific monomer, and (2) a ring-opening polymerization reaction for obtaining a ring-opening copolymer of a specific monomer and a copolymerizable monomer are metathesis It is carried out in the presence of a catalyst.
This metathesis catalyst comprises (a) at least one selected from W, Mo and Re compounds, (b) Deming periodic table group IA elements (for example, Li, Na, K, etc.), IIA group elements (for example, , Mg, Ca, etc.), Group IIB elements (eg, Zn, Cd, Hg, etc.), Group IIIA elements (eg, B, Al, etc.), Group IVA elements (eg, Si, Sn, Pb, etc.), or Group IVB A catalyst comprising a combination of at least one element selected from compounds having elements (for example, Ti, Zr, etc.) and having at least one element-carbon bond or the element-hydrogen bond. In this case, in order to increase the activity of the catalyst, an additive (c) described later may be added.

As typical examples of W, Mo or Re compounds suitable as the component (a), WCl ₆ , MoCl ₆ , ReOCl _{3 and the} like are disclosed in JP-A-1-132626, page 8, lower left column, line 6 to page 8, upper right. The compounds described in column 17th line can be mentioned.
(B) Specific examples of the _{component, n-C 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 and the like, the compounds described in JP-A-1-132626, page 8, upper right column, line 18 to page 8, lower right column, line 3 can be exemplified.
As typical examples of the component (c) which is an additive, alcohols, aldehydes, ketones, amines and the like can be suitably used, but further, JP-A-1-132626, page 8, lower right column, The compounds shown in line 16 to page 9, upper left column, line 17 can be used.

The amount of the metathesis catalyst used is a range in which “(a) component: specific monomer” is usually 1: 500 to 1: 50,000 in terms of the molar ratio of the component (a) to the specific monomer. The range is preferably 1: 1,000 to 1: 10,000.
The ratio of the component (a) to the component (b) is such that (a) :( b) is 1: 1 to 1:50, preferably 1: 2 to 1:30 in terms of metal atomic ratio.
The ratio of the component (a) to the component (c) is such that the molar ratio (c) :( a) is in the range of 0.005: 1 to 15: 1, preferably 0.05: 1 to 7: 1. The

<Solvent for polymerization reaction>
Examples of the solvent used in the ring-opening polymerization reaction (solvent constituting the molecular weight modifier solution, solvent for the specific monomer and / or metathesis catalyst) include alkanes such as pentane, hexane, heptane, octane, nonane, decane, Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, chlorobutane, bromohexane, methylene chloride, dichloroethane, hexamethylene dibromide, chlorobenzene, Compounds such as halogenated alkanes and aryl halides such as chloroform and tetrachloroethylene, saturated carbohydrates such as ethyl acetate, n-butyl acetate, iso-butyl acetate, methyl propionate, and dimethoxyethane Esters, dibutyl ether, tetrahydrofuran, and the like can be illustrated ethers such as dimethoxyethane, they can be used singly or in combination. Of these, aromatic hydrocarbons are preferred.
As the amount of the solvent used, “solvent: specific monomer (weight ratio)” is usually in an amount of 1: 1 to 10: 1, preferably in an amount of 1: 1 to 5: 1. The

<Molecular weight regulator>
The molecular weight of the resulting ring-opening (co) polymer can be adjusted by the polymerization temperature, the type of catalyst, and the type of solvent. In the present invention, the molecular weight is adjusted by allowing the molecular weight regulator to coexist in the reaction system. To do.
Here, suitable molecular weight regulators include, for example, α-olefins such as ethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and the like. Styrene can be mentioned, and among these, 1-butene and 1-hexene are particularly preferable.
These molecular weight regulators can be used alone or in admixture of two or more.
The amount of the molecular weight regulator used is 0.005 to 0.6 mol, preferably 0.02 to 0.5 mol, per 1 mol of the specific monomer subjected to the ring-opening polymerization reaction.

  (2) In order to obtain a ring-opening copolymer, a specific monomer and a copolymerizable monomer may be subjected to ring-opening copolymerization in the ring-opening polymerization step, and further, polybutadiene, polyisoprene, etc. In the presence of unsaturated hydrocarbon polymers such as conjugated diene compounds, styrene-butadiene copolymers, ethylene-nonconjugated diene copolymers, polynorbornene and the like containing two or more carbon-carbon double bonds in the main chain. The specific monomer may be subjected to ring-opening polymerization.

Although the ring-opening (co) polymer obtained as described above can be used as it is, (3) the hydrogenated (co) polymer obtained by further hydrogenation is a resin having high impact resistance. It is useful as a raw material.
<Hydrogenation catalyst>
In the hydrogenation reaction, a hydrogenation catalyst is added to a usual method, that is, a solution of a ring-opening polymer, and hydrogen gas at normal pressure to 300 atm, preferably 3 to 200 atm, is added thereto at 0 to 200 ° C., preferably 20 It is carried out by operating at ~ 180 ° C.
As a hydrogenation catalyst, what is used for the hydrogenation reaction of a normal olefinic compound can be used. Examples of the hydrogenation catalyst include a heterogeneous catalyst and a homogeneous catalyst.

  Examples of the heterogeneous catalyst include a solid catalyst in which a noble metal catalyst material such as palladium, platinum, nickel, rhodium, and ruthenium is supported on a carrier such as carbon, silica, alumina, and titania. In addition, homogeneous catalysts include nickel naphthenate / triethylaluminum, nickel acetylacetonate / triethylaluminum, cobalt octenoate / n-butyllithium, titanocene dichloride / diethylaluminum monochloride, rhodium acetate, chlorotris (triphenylphosphine) rhodium. Dichlorotris (triphenylphosphine) ruthenium, chlorohydrocarbonyltris (triphenylphosphine) ruthenium, dichlorocarbonyltris (triphenylphosphine) ruthenium, and the like. The form of the catalyst may be powder or granular.

These hydrogenation catalysts are used in such a ratio that the ring-opening (co) polymer: hydrogenation 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 characteristics deteriorate due to heating during molding and use as a product. There is no. Here, the hydrogenation rate is usually 50% or more, preferably 70% or more, and more preferably 90% or more.

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. is there. The higher the hydrogenation rate, the better the stability to heat and light, and when used as the wave plate of the present invention, stable characteristics can be obtained over a long period of time.
The hydrogenated (co) polymer used as the cyclic olefin resin of the present invention preferably has a gel content contained in the hydrogenated (co) polymer of 5% by weight or less. It is particularly preferable that the amount is not more than% by weight.

In addition, as the cyclic olefin-based resin of the present invention, (4) a (co) polymer obtained by cyclizing the ring-opened (co) polymer of the above (1) or (2) by a Friedel-Craft reaction and then hydrogenating it. Can be used.
<Cyclization by Friedel-Craft reaction>
The method for cyclizing the ring-opened (co) polymer of (1) or (2) by Friedel-Craft reaction is not particularly limited, but the acidic compound described in JP-A-50-154399 is used. Any known method can be employed. Specifically, Lewis acids such as AlCl ³ , BF ³ , FeCl ³ , Al ² O ³ , HCl, CH ³ ClCOOH, zeolite, activated clay, and Bronsted acid are used as the acidic compound.
The cyclized ring-opening (co) polymer can be hydrogenated in the same manner as the ring-opening (co) polymer (1) or (2).

Furthermore, as the cyclic olefin resin of the present invention, (5) a saturated copolymer of the specific monomer and an unsaturated double bond-containing compound can also be used.
<Unsaturated double bond-containing compound>
As an unsaturated double bond containing compound, ethylene, propylene, butene etc., Preferably it is C2-C12, More preferably, C2-C8 olefin type compound can be mentioned.
The preferred use range of the specific monomer / unsaturated double bond-containing compound is 90/10 to 40/60, more preferably 85/15 to 50/50, in weight ratio.

In the present invention, in order to obtain a saturated copolymer of (5) a specific monomer and an unsaturated double bond-containing compound, a usual addition polymerization method can be used.
<Addition polymerization catalyst>
As the catalyst for synthesizing the (5) saturated copolymer, at least one selected from a titanium compound, a zirconium compound and a vanadium compound and an organoaluminum compound as a promoter are used.
Here, examples of the titanium compound include titanium tetrachloride and titanium trichloride, and examples of the zirconium compound include bis (cyclopentadienyl) zirconium chloride and bis (cyclopentadienyl) zirconium dichloride.

Moreover, as the vanadium compound, the general formula VO _(OR) a _{X b} or V _(OR) c _{X d,}
[Wherein R is a hydrocarbon group, 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 an electron-donating adduct of these compounds.
Examples of the electron donor include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic acids or inorganic acids, ethers, acid amides, acid anhydrides, oxygen-containing electron donors such as alkoxysilanes, ammonia, amines, Examples thereof include nitrogen-containing electron donors such as nitrile and isocyanate.

Furthermore, as the organoaluminum compound as the promoter, at least one selected from those having at least one aluminum-carbon bond or aluminum-hydrogen bond is used.
In the above, for example, when the vanadium compound is used, the ratio of the vanadium compound to the organoaluminum compound is such that the ratio of aluminum atom to vanadium atom (Al / V) is 2 or more, preferably 2 to 50, particularly preferably 3 to 20. Range.

  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. Moreover, adjustment of the molecular weight of the (5) saturated copolymer obtained is normally performed using hydrogen.

Furthermore, as the cyclic olefin resin of the present invention, (6) an addition type of one or more monomers selected from the above specific monomer and a vinyl cyclic hydrocarbon monomer or a cyclopentadiene monomer Copolymers and their hydrogenated copolymers can also be used.
<Vinyl cyclic hydrocarbon monomer>
Examples of the vinyl cyclic hydrocarbon monomer include vinyl cyclopentene monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene, 4-vinylcyclopentane, 4-isopropenylcyclopentane and the like. Vinylated 5-membered hydrocarbon monomers such as vinylcyclopentane monomers, 4-vinylcyclohexene, 4-isopropenylcyclohexene, 1-methyl-4-isopropenylcyclohexene, 2-methyl-4-vinyl Vinylcyclohexene monomers such as cyclohexene and 2-methyl-4-isopropenylcyclohexene, vinylcyclohexane monomers such as 4-vinylcyclohexane and 2-methyl-4-isopropenylcyclohexane, styrene, α-methylstyrene, 2-methylstyrene, 3- Styrenic monomers such as styrene styrene, 4-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 4-phenylstyrene, p-methoxystyrene, d-terpene, 1-terpene, diterpene, d-limonene, 1- Terpene monomers such as limonene and dipentene, vinylcycloheptene monomers such as 4-vinylcycloheptene and 4-isopropenylcycloheptene, 4-vinylcycloheptane, 4-isopropenylcycloheptane, etc. And vinyl cycloheptane monomers. Styrene and α-methylstyrene are preferable. These can be used alone or in combination of two or more.

<Cyclopentadiene monomer>
Examples of the cyclopentadiene monomer used as the monomer of the addition copolymer (6) of the present invention include, for example, cyclopentadiene, 1-methylcyclopentadiene, 2-methylcyclopentadiene, 2-ethylcyclopentadiene, Examples include 5-methylcyclopentadiene and 5,5-methylcyclopentadiene. Cyclopentadiene is preferred. These can be used alone or in combination of two or more.

The addition type (co) polymer of at least one monomer selected from the above specific monomer, vinyl cyclic hydrocarbon monomer and cyclopentadiene monomer is the above (5) specific monomer. It can be obtained by the same addition polymerization method as the saturated copolymer of the unsaturated double bond-containing compound.
The hydrogenated (co) polymer of the addition type (co) polymer can be obtained by the same hydrogenation method as the hydrogenated (co) polymer of the above (3) ring-opening (co) polymer. .

Furthermore, as the cyclic olefin resin of the present invention, (7) an alternating copolymer of the specific monomer and acrylate can also be used.
<Acrylate>
Examples of the acrylate used in the production of the (7) alternating copolymer of the specific monomer and acrylate of the present invention include straight chain having 1 to 20 carbon atoms such as methyl acrylate, 2-ethylhexyl acrylate and cyclohexyl acrylate. C2-C20 heterocyclic group-containing acrylates such as chain, branched or cyclic alkyl acrylates, glycidyl acrylates, 2-tetrahydrofurfuryl acrylates, and aromatic ring groups containing 6-20 carbons such as benzyl acrylates Examples thereof include acrylates having a polycyclic structure having 7 to 30 carbon atoms such as acrylate, isobornyl acrylate, and dicyclopentanyl acrylate.

In the present invention, (7) In order to obtain an alternating copolymer of the specific monomer and acrylate, when the total of the specific monomer and acrylate is 100 mol in the presence of Lewis acid, The specific monomer is 30 to 70 mol, the acrylate is 70 to 30 mol, preferably the specific monomer is 40 to 60 mol, and the acrylate is 60 to 40 mol, particularly preferably the specific monomer. The polymer is radically polymerized at a ratio of 45 to 55 mol and acrylate of 55 to 45 mol.
(7) The amount of Lewis acid used to obtain the alternating copolymer of the specific monomer and acrylate is 0.001 to 1 mol per 100 mol of acrylate. Also, known organic peroxides or azobis radical polymerization initiators that generate free radicals can be used, and the polymerization reaction temperature is usually -20 ° C to 80 ° C, preferably 5 ° C to 60 ° C. . Moreover, the same solvent as used for the ring-opening polymerization reaction can be used as the solvent for the polymerization reaction.
The “alternate copolymer” as used herein refers to a structure in which the structural unit derived from the specific monomer is not adjacent, that is, the structural unit derived from the acrylate is always adjacent to the structural unit derived from the specific monomer. It means a copolymer having a structure as a unit, and does not deny a structure in which structural units derived from acrylate are 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 in terms of intrinsic viscosity [η] ^inh. The polystyrene-reduced number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 8,000 to 100,000, more preferably 10,000 to 80,000, and particularly preferably 12, The weight average molecular weight (Mw) is 20,000 to 300,000, more preferably 30,000 to 250,000, particularly preferably 40,000 to 200,000. It is.
Inherent viscosity [η] ^inh , number average molecular weight and weight average molecular weight are within the above ranges, so that the heat resistance, water resistance, chemical resistance, mechanical properties of the cyclic olefin resin and molding as the diffusion plate of the present invention Workability is improved.

  The glass transition temperature (Tg) of the cyclic olefin resin used in the present invention is usually 130 ° C. or higher, preferably 130 to 350 ° C., more preferably 130 to 250 ° C., and particularly preferably 140 to 200 ° C. When Tg is less than 130 ° C., it is not preferable because it is deformed by use under a high temperature condition or by secondary processing such as coating or printing. On the other hand, when Tg exceeds 350 ° C., the molding process becomes difficult, and the possibility that the resin is deteriorated by heat during the molding process increases.

  For the cyclic olefin-based resin, a specific hydrocarbon-based resin described in, for example, Japanese Patent Application Laid-Open Nos. 9-221577 and 10-287732, or a known heat can be used without departing from the effect of the present invention. Plastic resins, thermoplastic elastomers, rubber polymers, organic fine particles, inorganic fine particles and the like may be blended.

  The cyclic olefin resin of the present invention includes known antioxidants such as 2,6-di-tert-butyl-4-methylphenol, 2,2′-dioxy-3,3′-di-tert-butyl- 5,5′-dimethyldiphenylmethane, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane; UV absorbers such as 2,4-dihydroxybenzophenone, 2-hydroxy- It can be stabilized by adding 4-methoxybenzophenone or a benzyl malonate compound. Further, additives such as a lubricant can be added for the purpose of improving processability.

  A method for molding the above cyclic olefin-based resin into a film is not particularly limited, and a known molding method can be employed. For example, either a hot melt molding method or a solution casting method can be employed, but from the viewpoint of reducing volatile components in the sheet, it is preferable to use the hot melt molding method.

  Examples of the heat melt molding method include a melt extrusion molding method, a press molding method, an inflation method, an injection molding method, a blow molding method, and a stretch molding method. Among these, in order to obtain a stretched film having excellent mechanical strength and surface accuracy, it is preferable to use a melt extrusion molding method.

  The molding conditions are appropriately selected depending on the purpose of use and the molding method. In the melt extrusion molding method, usually, before the resin is charged into the extruder, the moisture, gas (oxygen, etc.), residual solvent, etc. contained in the resin are removed in advance for the purpose of removing the Tg or less of the resin. Dry resin pellets at an appropriate temperature. The dryer used for drying is not particularly limited. Usually, an inert gas circulating dryer such as a hot air circulating dryer, a dehumidifying dryer, a vacuum dryer, or nitrogen is used in the copolymer. In view of efficiently removing volatile components or dissolved oxygen, it is particularly preferable to use an inert gas circulation dryer or a vacuum dryer. In order to suppress moisture absorption and oxygen absorption in the hopper, it is also preferable to seal the hopper with an inert gas such as nitrogen or argon, or to use a vacuum hopper that can be kept under reduced pressure. In addition, the extruder cylinder should be provided with a vent function to eliminate volatile components generated during melt extrusion and a function to seal with an inert gas such as nitrogen or argon in order to push the deterioration of the polymer due to oxygen contamination. Is preferred.

As the extruder, a single-screw, twin-screw, or satellite multi-screw extruder is usually used.
The melted cyclic olefin-based resin can be discharged from a flat die and adhered and solidified on a cooling drum to obtain a target film. Specific examples of the flat die include a manifold die, a fish tail die, and a coat hanger die. Among these, a coat hanger die and a manifold die are preferable. Examples of the material of the extruder (cylinder, screw, etc.) and the die include, but are not limited to, SCM steel and stainless steel such as SUS. In addition, the inner surface of the extruder cylinder, die and the screw surface of the extruder are plated with chromium, nickel, titanium, etc., PVD (Physical Vapor Deposition) method, etc., TiN, TiAlN, TiCN, CrN, DLC It is preferable to use a film on which a film such as (diamond-like carbon) is formed, a film in which tungsten carbide or other ceramic is sprayed, or a film in which the surface is nitrided. Such a surface treatment is preferable in that a uniform molten state of the resin can be obtained because the coefficient of friction with the resin is small.

Examples of the method for tightly solidifying the film extruded from the die include a nip roll method, an electrostatic application method, an air knife method, a vacuum chamber method, a calendar method, and a sleeve method. A method is selected.
Various surface treatments are preferably performed on the surface of the cooling roll for solidifying the film extruded from the die as well as the extruder cylinder and the inner surface of the die. These surface treatments prevent the adhesion of the extruded film to the roll surface and prevent the occurrence of uneven thickness of the film. Also, the surface accuracy of the cooling roll is increased, and the surface hardness is high, so that the film is not easily damaged. Even if it manufactures, it is preferable at the point which can maintain the film surface precision stably and can manufacture a film without a thickness spot.

  Here, as the melt extrusion conditions for obtaining the melt-extruded film of the present invention, for example, the resin temperature (extruder cylinder temperature) is usually 100 to 500 ° C., preferably 150 to 350 ° C., and shear during melt extrusion. The speed is usually 1-1000 (1 / Sec.), Preferably 2-500 (1 / Sec.), More preferably 5-300 (1 / Sec.). If the resin temperature is less than 100 ° C., the resin cannot be melted uniformly. On the other hand, if the resin temperature exceeds 500 ° C., the resin is thermally degraded at the time of melting, making it difficult to produce a high-quality film with excellent surface properties . Also, if the shear rate during extrusion is less than 1 (1 / Sec.), The resin cannot be uniformly melted, so that an extruded film with small thickness unevenness cannot be obtained, while 1000 (1 / Sec.). If it exceeds 1, the shearing force is too large, the resin and additives are decomposed and deteriorated, and defects such as foaming, die lines and deposits occur on the surface of the extruded film.

The present invention is characterized in that a die for melt extrusion is sealed with an inert gas during heating or heat retention.
Here, examples of the inert gas include nitrogen, argon and the like, but other gases including 10% or less, preferably 2% or less, more preferably 1% or less, and particularly preferably 0.1% or less are included. It may be.
As the inert gas of the present invention, known ones can be used, but nitrogen or argon is preferable from the viewpoint of ease of handling and availability, and purity is preferably 98 from the viewpoint of effect. % Or more, more preferably 99% or more, particularly preferably 99.9% or more. If the purity is less than 98%, the sealing effect is insufficient due to the presence of an active gas such as oxygen contained as an impurity, which is not preferable.
The production method of these inert gases having high purity is not particularly defined, and a known method is used. Further, a method of gradually flowing a product in which these manufactured inert gases are sealed in a cylinder may be used, but it is preferable to use a known membrane separation or pressure vibration method, preferably from air dehumidified by a known method. A method of continuously separating the target inert gas and flowing it to the die is also preferable.
Flow rate of nitrogen is preferably 0.06 m ³ / hr or more 1.2 m ³ / hr or less, more preferably, less 0.3 m ³ / hr or more 0.9 m ³ / hr. Is less than 0.06 m 3 ^/ hr is insufficient sealing with the inert gas, whereas, since it exceeds 1.2 m 3 ^/ hr heating die results in a problem that temperature unevenness of insufficient or die undesirable .

As the inert gas used in the present invention, it is preferable to use a gas filtered by a known filter in order to prevent foreign matters from being mixed in the extrusion operation of the resin melt film.
The aperture of the filter to be used is usually 5 μm or less, preferably 2 μm or less, particularly preferably 1 μm or less, and a filter made of a known material such as polytetrafluoroethylene (trade name: Teflon) or nylon can be used. It is.

  The method of sealing the die with an inert gas is not particularly limited as long as the die can be sealed with an inert gas and an active gas such as oxygen is not mixed. For example, it can be sealed from a die flange, an inlet channel tube, a side surface, a die outlet, etc. This is preferable because it is not necessary to provide a special structure that may cause the resin to stay.

  As a method of setting the die outlet to an inert gas atmosphere, it is possible to employ a method in which the die slip portion is covered with a cover and an inert gas is allowed to flow there. The material of these covers is not particularly limited. However, in order to suppress the occurrence of foreign substances due to the high temperature of the dies, it is usually preferable to use a corrosion-resistant metal, preferably a stainless steel material or an aluminum metal material. .

Sealing the die with an inert gas requires that the gap through which the molten resin flows inside the die is filled with the inert gas at least when the molten thermoplastic resin is supplied into the die. . Also, in order to suppress oxidation of the surface of the flow path inside the die, an inert gas is allowed to flow into the die from the time when the die is not sufficiently heated, preferably at or before the temperature rise of the die is started. It is also preferable to keep it sealed. Further, when the molten resin remains in the die, it is preferable to seal with an inert gas at least at a glass transition temperature Tg or lower, preferably Tg-50 ° C. or lower of the thermoplastic resin to be used.
Moreover, when keeping a film extrusion apparatus warm, it is preferable to stop the operation of an extruder and to start sealing with an inert gas when the outflow of the film-like resin from the die stops.

  The thickness of the unstretched film can be appropriately determined according to the purpose of use of the stretched film obtained. The thickness of the film is preferably 40 to 200 μm, more preferably 50 to 150 μm, from the viewpoint of obtaining a uniform stretched film by a stable stretching process.

[Stretching method]
In the present invention, the unstretched film made of the resin such as acetate film or cyclic olefin resin is continuously obliquely stretched in an arbitrary angle θ (5 degrees ≦ θ <85 degrees) with respect to the width direction. Thus, a long stretched film having an orientation axis at an angle θ with respect to the width direction of the film can be obtained.

  By setting the angle θ to an arbitrary value between 5 and 85 degrees, the refractive index nx in the in-plane slow axis direction, the refractive index ny in the direction perpendicular to the in-plane slow axis, and the thickness direction The refractive index nz can be set to a desired value. When the angle θ is less than 5 degrees and greater than 85 degrees, there are few merits of performing oblique stretching. In addition, the preferable angle of the diagonal stretch in this invention is 10 to 85 degree | times, More preferably, it is 20 to 80 degree | times.

  The oblique stretching method is not particularly limited as long as it is continuously stretched in a direction of 5 to 85 degrees with respect to the width direction and the polymer orientation axis is inclined to a desired angle. Can be adopted.

  In addition, the stretching machine used for the oblique stretching is not particularly limited, and a conventionally known tenter type stretching machine that can add feeding force, pulling force, or pulling force at different speeds in the horizontal or vertical direction can be used. it can. In addition, the tenter type stretching machine includes a horizontal uniaxial stretching machine, a simultaneous biaxial stretching machine, and the like, but is not particularly limited as long as a long film can be continuously obliquely stretched. These types of stretching machines can be used.

  An example of oblique tenter stretching that can be used in the present invention is shown in FIG. As shown in FIG. 1, the unstretched film UF obtained above is stretched obliquely using a tenter TE while being conveyed in a certain direction MD. The film chucked at the positions P1 and P2 in FIG. 1 is obliquely stretched by moving the left side to the position P4 at a slow speed SL and moving the right side to the position P3 at a high speed SR. A stretched film DF is obtained. FIG. 1 shows an example in which the film is obliquely stretched at an angle θ (1 ≦ θ ≦ 85) with respect to the width direction A, and the orientation axis is the direction of B.

The oblique stretching method that can be used in the present invention is not limited to that shown in FIG. For example, those described in JP 2000-9912 A, JP 2002-86554 A, JP 2002-22945 A, and the like can be used.
In addition, as the method of oblique stretching, there are a method in which the left and right point tars of the lateral stretching have a speed difference, a method of stretching at an asymmetric angle, or a combination thereof.
Furthermore, the stretching speed is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, and more preferably 100 to 1,000% / min.

  The temperature at which the unstretched film is obliquely stretched is preferably between Tg-30 ° C and Tg + 60 ° C, more preferably Tg-10 ° C, where Tg is the glass transition temperature of a resin such as cellulose acetate or cyclic olefin resin. To Tg + 50 ° C. Moreover, a draw ratio is 1.1-5.0 times normally, Preferably it is 1.1-3.0 times, More preferably, it is 1.1-2.0 times.

In the present invention, in this oblique stretching, the stretched film has a temperature distribution in the width direction.
Specifically, the temperature distribution of the resin film is set such that the temperature in the center portion in the width direction has a temperature difference of 10 ° C. at the maximum compared to the end portion.
More preferably, the temperature of the resin film is in the range of Tg-30 ° C. to Tg + 60 ° C. (where Tg is the glass transition temperature of the resin), and the film temperature at the center in the film width direction is at the end. 1-10 ° C. higher than the film temperature.
To further explain with reference to FIG. 1, the temperature of FC, which is the central portion in the width direction of the resin film, is set to be lower than the end portions (FSL, FSR) of the resin film by a temperature difference of 10 ° C. at the maximum.

As a specific example of this temperature distribution, when the width of the obtained obliquely stretched film is 1,200 mm, (1) 100 mm, (2) 350 mm, (3) 600 mm, (4) 850 mm, ( 5) As a temperature at a position of 1,100 mm, the following setting is preferable for a resin film having a glass transition temperature of 165 ° C. or a resin film having the same temperature of 120 ° C., for example.
Film of Tg = 165 ° C .: (1) 180 ° C., (2) 177 ° C., (3) 175 ° C., (4) 178 ° C., (5) 180 ° C.
Films with Tg = 120 ° C .: (1) 133 ° C., (2) 129 ° C., (3) 125 ° C., (4) 129 ° C., (5) 133 ° C.
In the above-mentioned positions (1) to (5), the oblique stretching obtained by increasing the film temperature at the central part in the film width direction with a temperature difference higher than that at the end as compared with the case of the same temperature. Optical properties such as phase difference and optical axis of the film are uniform.

  As described above, it is preferable that the temperature of the resin film is 0.5 to 10 ° C. lower than the film temperature at the end in the film width direction. When the temperature difference exceeds 10 ° C., the homogeneity of the resulting film is lowered, and the higher the stretching temperature, the smaller the phase difference expressed by stretching, and the more relaxed orientation after stretching, so the balance of homogeneity is lost. . On the other hand, if the temperature difference is less than 0.5 ° C., the effect of preventing the bowing phenomenon is dilute, which is not preferable. In addition, the temperature of the reference film center part (FC) is preferably −15 ° C. to + 30 ° C., more preferably −10 ° C. to + 25 ° C., with respect to the glass transition temperature (Tg) of the resin constituting the film. Particularly preferred is -5 ° C to + 20 ° C.

In the present invention, the temperature distribution in the width direction is basically symmetric with respect to the center in the width direction, but may be asymmetric according to the film thickness distribution.
As a method of giving a temperature distribution in the width direction of the resin film, an infrared heater or the like is used in a certain section in a temperature chamber under uniform temperature control of ± 1.0 ° C. to ± 0.5 ° C. The method of giving temperature distribution only to the stretched film part is mentioned.
In addition, the method of heating locally is not limited to infrared rays. Moreover, a heating direction may be parallel to the width direction of a film, and may have an angle with respect to the width direction in the same angle range according to the angle of diagonal stretching.

The obliquely stretched film of the present invention obtained as described above has an orientation axis of 5 to 85 degrees with respect to the width direction. Further, since there is no wrinkle or thickness unevenness, no dimensional change over a long period of time, and excellent optical properties, it is useful as a polarizing film or a retardation film.
The thickness of the obliquely stretched film is usually 20 to 120 μm, preferably 25 to 100 μm.
In addition, as long as the film applied to the oblique stretching of the present invention is a film formed into a uniform film thickness with an average film thickness within ± 5%, such as a solution casting method film or a melt-extruded film, any film can be used. Such a processing method may be used.

Examples of the present invention are shown below, but the present invention is not limited to the examples.
In the following, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified.
Various measurement items are values obtained as follows.

Glass transition temperature (Tg)
According to JIS K 7121, a differential scanning calorimeter (DSC) was used and measured at a temperature increase rate of 20 ° C./min in a nitrogen atmosphere.
Hydrogenation rate
^It was determined from the proton ratio of the proton on the carbon-carbon double bond of ¹ H-NMR and the methyl proton of the carboxymethyl group.
Intrinsic viscosity (η _inh )
The intrinsic viscosity of the chloroform solution of the sample prepared to a concentration of 0.5 g / dl was measured at 30.0 ° C. using an Ubbelohde viscometer.

Synthesis example 1
8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . In a reaction vessel in which 250 parts of 1 ^7,10 ] -3-dodecene (specific monomer), 41 parts of 1-hexene (molecular weight regulator) and 750 parts of toluene (solvent for ring-opening polymerization reaction) were replaced with nitrogen The solution was heated to 60 ° C. Next, 0.62 parts of a toluene solution of triethylaluminum (1.5 mol / l) and tungsten hexachloride modified with t-butanol / methanol (t-butanol: methanol: tungsten = 0.20) were added to the solution in the reaction vessel. 37 parts of a toluene solution (concentration 0.05 mol / l) of 35 mol: 0.3 mol: 1 mol) was added, and this system was heated and stirred at 80 ° C. for 3 hours to cause a ring-opening polymerization reaction. Thus, a ring-opening polymer solution was obtained.
The polymerization conversion rate in this polymerization reaction was 97%.
The autoclave was charged with 4,000 parts of the ring-opening polymer solution thus obtained, and RuCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opening polymer solution. 0.48 parts was added, and hydrogenation reaction was carried out by heating and stirring for 3 hours under the conditions of a hydrogen gas pressure of 100 kg / cm ² and a reaction temperature of 165 ° C.
After cooling the obtained reaction solution (hydrogenated polymer solution), the hydrogen gas was released.
The hydrogenation rate of the hydrogenated polymer thus obtained was measured by ¹ H-NMR at 400 MHz and found to be substantially 100%.
The intrinsic viscosity (η _inh ) of the polymer was 0.50, and the glass transition temperature measured with a scanning calorimeter (DSC) at a rate of temperature increase of 20 ° C./min in a nitrogen atmosphere was 165 ° C.

Synthesis example 2
8-Methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 as a specific monomer
. 1, ¹⁰ ] -3-dodecene 225 parts and bicyclo [2.2.1] hept-2-ene 65 parts, except that 1-hexene (molecular weight regulator) was added in 43 parts Obtained a hydrogenated polymer in the same manner as in Synthesis Example 1. The hydrogenation rate of the obtained hydrogenated polymer was substantially 100%.
The intrinsic viscosity (η _inh ) measured in chloroform at 30 ° C. of the polymer was 0.50, and the glass transition temperature was 120 ° C.

<Example 1 of film formation>
A thoroughly cleaned T-die with a width of 500 mm was attached to a 50 mmφ extruder. Before starting to raise the temperature of the die and the extruder, sealing is performed by flowing 99.9% purity nitrogen at a flow rate of 0.6 m ³ / hr from an aluminum cover attached to the die slip part. And began to raise the temperature of the extruder.
After sufficiently raising the temperature over 5 hours from the start of raising the temperature, the resin obtained in Synthesis Example 1 that was vacuum-dried under the conditions of 100 ° C. × 4 hours, the extruder cylinder temperature was set to an appropriate temperature of 280 to 300 ° C. Then, it was melt-extruded under the condition of a shear rate of 32 (1 / Sec.) To form a film. The film melt-extruded from the T-die is sandwiched between the metal cast drum and a metal endless belt provided so as to be pressed against the cast drum along the circumferential direction thereof. After pressing the endless belt and processing the film surface with high accuracy, the film was peeled from the belt to produce an extruded film having a width of 450 mm and a thickness of 100 μm. The cooling cast drum was set at a temperature of 145 ° C. for molding.

<Example 2 of film formation>
Extruded film having a thickness of 100 μm was obtained in the same manner as in Example 1 except that the resin obtained in Synthesis Example 2 was used, the extruder cylinder temperature was set to 255 to 280 ° C., and the cooling cast drum was set to 105 ° C. .
The sample film (Tg 165 ° C.) obtained in Synthesis Example 1 and Film Formation Example 1 and the sample film (Tg 120 ° C.) obtained in Synthesis Example 2 and Film Formation Example 2 were used as samples.

<Examples 1-6, Comparative Examples 1-4>
The optical film obtained in the above synthesis examples and film forming examples was stretched 1.3 times under the conditions shown in Table 1 with a temperature distribution using a stretching machine according to FIG. The film was obliquely stretched at θ = 45 °.
With respect to the obtained stretched film, the orientation angle (stretch orientation angle with the roll film length direction (so-called MD direction) being 0 degree) for each part of the film shown in Table 1 was manufactured by Oji Scientific Instruments. The measurement was performed using an automatic birefringence meter “KOBRA-21ADH”, and the difference between the measured value and the target orientation angle (45 °) was determined. If this difference is within ± 0.5 °, it can be said that the orientation in the width direction is uniform.

  The obliquely stretched film obtained by the present invention is a polarizing film, protective film, retardation film, viewing angle compensation film, polarizing plate protection / retardation film, polarizing plate protection / viewing angle in various display panels represented by liquid crystal and plasma. In addition to a compensation film, it is particularly useful as various films having little strength anisotropy. Other than this, for example, various liquid crystal display elements such as mobile phones, digital information terminals, pagers, navigation, liquid crystal displays for vehicles, liquid crystal monitors, light control panels, displays for OA devices, displays for AV devices, electro It can be used for a luminescence display element or a touch panel. It is also useful as a wave plate used in an optical disk recording / reproducing apparatus such as a CD, CD-R, MD, MO, and DVD.

It is the schematic which shows the film processing method of this invention.

Explanation of symbols

UF: Unstretched film MD: Machine direction (film length direction)
P1, P2: Chuck point SL: Left side speed SR: Right side speed DF: Stretched film A: Width direction B: Orientation axis

Claims (4)

  A method for continuously processing a resin film in a direction of 5 to 85 degrees with respect to its width direction, wherein the film at the time of stretching has a temperature distribution in its width direction.   The film processing method according to claim 1, wherein the temperature distribution of the resin film is a distribution in which the temperature in the center portion in the width direction has a temperature difference of 10 ° C. at the maximum compared to the end portion.   The temperature of the resin film is in the range of Tg−30 ° C. to Tg + 60 ° C. (where Tg is the glass transition temperature of the resin), and the film temperature at the center in the film width direction is 0 from the film temperature at the end. The film processing method according to claim 1 or 2, which is lower by 5 to 10 ° C. The film processing method according to claim 1, wherein the resin constituting the resin film is cellulose acetate or a cyclic olefin resin.

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