JP2010211013A - Twisted nematic type liquid crystal display device and method of manufacturing cycloolefin resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a twisted nematic type liquid crystal display device, remarkably improving performance related to visibility such as viewing angle, reversal of halftone and blocked-up shadows, and lateral hue change in white which causes a problem in the TN type liquid crystal display device. <P>SOLUTION: When the refractive indexes in three directions of a film are na, nb, nc, they are related to each other by na≥nb≥nc (the refractive indexes na, nb, nc are the refractive indexes in three directions of a measuring surface having the minimum phase difference when the phase difference in two component directions of the measuring surface is measured while the film is inclined). In this twisted nematic type liquid crystal display device, the cycloolefin resin film, which inclines at an angle α of 5-50°from the film surface normal direction having the refractive index nc, is provided at least between a twisted nematic type liquid crystal cell and a first polarizer or between the liquid crystal cell and a second polarizer. Further a scattering film formed by dispersing scatterers in transparent resin is provided at least on the observation side of the first polarizer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a twisted nematic liquid crystal display device, and in particular, the performance related to visibility such as viewing angle, halftone inversion, and blackout, and the change in white color in the horizontal direction, which is particularly problematic in TN liquid crystal display devices. The present invention relates to an improved twisted nematic liquid crystal display device and a method for producing a cycloolefin resin film suitable for the twisted nematic liquid crystal display device.

  Twist nematics (hereinafter referred to as optical rotation mode) are used for notebook PCs and desktop monitors because low power consumption, thinning, and price reduction are more important than video performance and ultra-wide viewing angle characteristics like LCD TVs. Many devices adopt the type drive system.

  However, since the TN type drive system has a very narrow viewing angle as it is, it is necessary to enlarge the viewing angle, and a retardation having a liquid crystal layer coated, aligned and polymerized as shown in Patent Document 1. A film is used. In recent years, the response speed of the TN system has also increased, and since it has been adopted in some liquid crystal TVs, there is an increasing demand for viewing angle expansion.

  However, in the TN type display device using the retardation film, although the contrast viewing angle indicated by the light quantity ratio of white and black is widened, there remains a big problem with the halftone inversion and blackout that are important for practical performance. In addition, there is a problem of poor visibility that the white color in the horizontal direction changes.

  In addition, the retardation film has a complicated configuration and a manufacturing method, and has a problem of low productivity and high cost.

  On the other hand, a retardation film having an optical axis inclined from the normal direction of the film surface has been proposed as a simple resin film that is excellent in productivity and does not require a liquid crystal layer (see, for example, Patent Documents 2 and 3). .

  These are methods in which a film is sandwiched between two rollers having different peripheral speeds, and a shearing force is applied in the surface direction of the film to impart distortion deformation to the film and tilt the optical axis from the film surface direction. . However, although the polycarbonate film proposed in the patent document can obtain a desired optical axis inclination, it has a high photoelastic coefficient, so shearing unevenness is likely to occur, and retardation unevenness and orientation angle unevenness are remarkably increased. There were still problems with the widening of the expected viewing angle, halftone inversion, blackout, and lateral white color change.

JP 2002-156527 A JP-A-6-222213 JP 2003-25414 A

  Accordingly, an object of the present invention is to provide a twisted nematic type in which the performance related to visibility such as viewing angle, halftone inversion, blackening, and the white color change in the horizontal direction, which is particularly problematic in the TN type liquid crystal display device, are remarkably improved. The object is to provide a liquid crystal display device. Furthermore, it is providing the manufacturing method of the cycloolefin type resin film suitable for this twist nematic type liquid crystal display device.

  The above object of the present invention is achieved by the following configurations.

1. Twisted nematic liquid crystal cell, first polarizer provided on the viewing side of the liquid crystal cell, twisted nematic liquid crystal display having a second polarizer and a backlight unit provided on the backlight side of the liquid crystal cell In the device
When at least one of the liquid crystal cell and the first polarizer and at least one of the liquid crystal cell and the second polarizer has a refractive index in three directions of na, nb, and nc, na ≧ nb> nc, and has a cycloolefin resin film in which the angle α from the normal direction of the film surface of the refractive index nc is inclined by 5 to 50 °, and at least on the viewing side of the first polarizer A twisted nematic liquid crystal display device comprising a scattering film in which a scatterer is dispersed in a transparent resin.
(However, the refractive indexes na, nb, and nc are the refractive indexes in the vertical direction of the measurement surface that minimizes the phase difference when measuring the phase difference in the two-component direction of the measurement surface while tilting the film. Is nc, and the refractive indices in the two-component directions orthogonal to each other on the measurement surface are na and nb.)
2. The cycloolefin-based resin film is stretched, and Ro1 represented by the following formula (i) is in the range of 5 to 35 nm, and Rth1 represented by the following formula (ii) is in the range of 70 to 150 nm. 2. The twisted nematic liquid crystal display device as described in 1 above.

(I) Ro1 = (na−nb) × d
(Ii) Rth1 = ((na + nb) / 2−nc) × d
(However, the refractive indexes na, nb, and nc are the refractive indexes in the vertical direction of the measurement surface that minimizes the phase difference when measuring the phase difference in the two-component direction of the measurement surface while tilting the film. Where nc is the refractive index in the two-component directions perpendicular to each other on the measurement surface, and na and nb, where each refractive index is a value for light with a wavelength of 590 nm, and d is the film thickness (nm). Represents.)
3. The scatterer contained in the scattering film is a particle having a volume average particle diameter of 1.0 to 7.0 μm, and a difference in refractive index between the transparent resin and the scatterer is 0.02 or more. 2. The twisted nematic liquid crystal display device as described in 1 above.

4). A method for producing the cycloolefin-based resin film according to 1 or 2,
When the refractive index for light with a wavelength of 590 nm of the cycloolefin-based resin film before rolling is nx, ny, nz, (x: film width direction, y: film transport direction, z: film thickness direction) )
Retardation value (d represents thickness (nm) of cycloolefin resin film)
Ro2 = (nx−ny) × d is 0 to 90 nm,
Rth2 = ((nx + ny) −nz) / 2 × d is 0.01 to 30 nm,
Nz2 = (nx−nz) / (nx−ny) is 0.5 to 3,
A cycloolefin-based resin film,
Using at least one pair of calendar rollers,
While conveying the film transport tension (T) at 0.4 <T <20 MPa,
The linear pressure p when nipping with the calender roller is 150 to 1000 [kN / m],
The peripheral speed ratio n of the two rollers of the calendar roller is 0.01 to 0.6,
(Where n = (V1-V2) / V1 V1, V2: peripheral speed of a pair of rollers, V1> V2)
A method for producing a cycloolefin-based resin film, wherein a rolling treatment is performed while a value Q = T / Nz2 obtained by dividing the film transport tension T by an Nz2 coefficient is adjusted to a range of 0.2 <Q <40.

  According to the present invention, a twisted nematic type liquid crystal in which the performance related to visibility such as viewing angle, halftone inversion, blackout, and the lateral white color change which are particularly problematic in a TN type liquid crystal display device are remarkably improved. A display device can be provided. Furthermore, the manufacturing method of the cycloolefin type resin film suitable for this twist nematic type liquid crystal display device can be provided.

It is a conceptual diagram which shows the effect of the drive roller and a follower rotation roller with respect to a film. It is a schematic diagram which shows the example of arrangement | positioning of the drive roller and follower rotation roller which concern on this invention. It is a schematic diagram of the rolling processing apparatus using the preheating roller preferable in this invention. This is a configuration example using the optical compensation film of the present invention for a TN liquid crystal display. It is a conceptual diagram which shows the relationship between the twist angle of the liquid crystal of a polarizing plate, a rubbing axis | shaft, and a transmission axis.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  In addition to suppressing halftone inversion, suppression of blackout, and expansion of viewing angle, which are practical performances of a TN type liquid crystal display device, the present invention particularly suppresses white color change in the horizontal direction with a tilted optical axis. This is achieved by combining an olefin resin film and a scattering film in which a scatterer is dispersed in a transparent resin.

  As a result of the study by the present inventors, it is possible to enlarge the viewing angle to some extent in a retardation film having a liquid crystal layer coated, oriented and polymerized, or a polycarbonate resin film having an inclined optical axis. However, it has been found that there are still problems with respect to the visibility performance such as halftone inversion, blackening, and viewing angle expansion, and particularly the lateral white color change which is a problem.

  Therefore, as a result of further investigation, a cycloolefin resin film having an inclined optical axis was used as a retardation film between the polarizer and the liquid crystal cell, and a scatterer was dispersed in the transparent resin at least on the viewing side of the polarizer. In addition to suppressing halftone inversion, suppression of blackout, and widening of the viewing angle, it was found that the use of the scattering film made can significantly improve the white color change in the horizontal direction, and has led to the present invention. It depends on you.

  This is because the cycloolefin resin has a lower photoelastic coefficient than the polycarbonate resin, so that the unevenness of the shearing force hardly occurs in the specific rolling process when the optical axis is inclined as in the present invention. Presumably, the occurrence of retardation unevenness and orientation angle unevenness over the entire area is small, and color correction by viewing angle is possible by using a scattering film at least on the viewing side of the polarizer, and the effects of the present invention are achieved. Is done.

  Hereinafter, the cycloolefin resin film having an inclined optical axis according to the present invention may be referred to as a retardation film.

<Characteristics of the method for producing a retardation film of the present invention>
The method for producing a retardation film of the present invention is a method in which an optical axis is inclined from the normal direction of the film surface, and a method of forming a shearing stress in a resin film by rolling to give a strain deformation is preferable.

  More specifically, a method of sandwiching between two or more rollers having different hardness at constant speed, a method of sandwiching between rollers or belts having different peripheral speeds, or a substrate (drum Shear rolling process using a method to control the peeling angle and peeling tension when peeling from a belt, etc., or using a method that does not rotate or drive the opposite side of the roller when transporting the axis of the resin film or roller To create. These treatments are generally preferably carried out at a resin film treatment temperature in the range of Tg (glass transition temperature of the resin film) -50 ° C. to Tg + 150 ° C.

  Among them, the driving roller is brought into contact with one surface of the resin film, the follower rotating roller having a rotational load is brought into contact with the opposite surface of the resin film, and the resin film is conveyed, thereby giving distortion deformation to the resin film, It is preferable to tilt the optical axis.

  Here, the “following rotating roller having a rotational load” is a rotating roller that freely rotates or forcibly rotates according to the contact pressure with the conveyed resin film, as shown in FIG. 1, and the film is conveyed by the driving roller. A rotating roller used to apply a force in the opposite direction so that the brake is applied on the film surface opposite to the film surface on which the force to be applied is applied. Various brakes can be used for the load required for rotation. As a point, it is important to have a structure in which the load torque does not fluctuate, and it is necessary to perform control so that a constant torque including the driving roller is obtained.

  Also, “giving distortion deformation to the resin film” means applying shearing force due to contact pressure with a roller or roller nip pressure to the resin film and optical properties such as refractive index in the resin film (“optical characteristics”). To cause distortion and deformation.

  As an embodiment of the present invention, it is preferable that the resin film does not slip between the contact portion of the two types of rollers, the driving roller and the following rotation roller. For this reason, it is preferable that the drive roller and the follower rotation roller constitute an nip roller pair that sandwiches the resin film. Accordingly, the resin film is prevented from slipping on the outer peripheral surfaces of the drive roller and the follower rotation roller, and thus the film surface is not scratched. Further, the stress transmitted from the driving roller and the follower rotating roller to the film is stable, and variation in the amount of distortion in the film is small.

  In the present invention, there may be at least a pair of the driving roller or the follower rotating roller. However, it is also preferable that a plurality of driving rollers or following rotation rollers are provided and the contact is performed at a plurality of locations on the film conveyance path.

  Forming a certain amount of strain deformation in multiple steps is superior in that the amount of variation can be reduced more stably than forming strain deformation once. In addition, when strain deformation is given in a plurality of times, a region to be heated in the film thickness direction is partially limited and the heating position is changed a plurality of times so that the strain deformation amount varies in the film thickness direction. Can be preferable.

  Therefore, as a manufacturing apparatus used for carrying out the method for manufacturing a retardation film of the present invention, basically, a driving roller that contacts one side of a resin film and a follower that contacts the opposite surface of the resin film and has a rotational load. It is preferable that the retardation film manufacturing apparatus includes a rotating roller, and these two types of rollers serve as a means for conveying the resin film and serve as a means for imparting distortion deformation in the resin film.

  Regarding distortion deformation in the resin film according to the present invention, the amount of deformation in the film can be easily controlled by means shown in the following (1) to (7), and production stability by continuous conveyance of the resin film is good. It is.

  (1) The load amount of the rotational load of the following rotary roller is adjusted.

  (2) The film temperature of the part (contact part and its front and back) where the shear force is applied is adjusted.

  (3) The temperature state in the surface direction of the film is adjusted in (2) above. For example, the temperature difference from the non-heating (cooling) side by heating from one side is adjusted including the preheating time.

  (4) A follower rotating roller having a driving roller and a rotational load is used as a roller nip pair, and the number of roller nip pairs used is adjusted.

  (5) In the above (4), the rotational load amount of the following rotating roller is adjusted to be gradually increased or decreased with the plurality of roller nip pairs.

  (6) The roller temperature is changed by the plurality of roller nip pairs of the above (4) and (5), and the film temperature to be heated at the plurality of contact portions is adjusted.

  (7) The roller deformation amount is adjusted by selecting the roller material (metal, various rubbers).

  (8) A heating means is provided on one side of the film, and a cooling means is provided on the opposite side.

  Hereinafter, the technical features of preferred embodiments of the method for producing a retardation film of the present invention will be described in more detail with reference to FIGS.

  FIGS. 2A to 2D are conceptual diagrams showing an arrangement example (positional interrelation example) of the driving roller and the follower rotating roller according to the present invention. In the case of the example shown in FIG. 2 (a), the roller does not nip, and the film is in close contact with the outer periphery of the roller, and the roller diameter can be reduced to form a small curved portion to give distortion deformation. Thus, distortion deformation different from that in FIG. 2B can be given. By changing the temperature of the plurality of rollers or changing the roller diameter, distortion deformation that cannot be obtained by the roller nip pair method can be given.

  In the case of the example shown in FIG. 2B, the mass of the roller can be used for the rotational load of the following rotary roller, and the variation in the roller width direction is reduced. The slip limit can be increased by the roller nip pressure, and a strong force can be transmitted by one pair of rollers, and the amount of deformation in the film by one pair of rollers can be increased.

  In the case of the example shown in FIG. 2C, the manufacturing process can be reduced by pairing a plurality of rollers with respect to one roller. The inside of the resin film on one surface of the resin film can be deformed by using the driving roller as a cooling roller and the follower rotating roller as a heating roller. In FIG. 2 (c), by setting the reverse roller arrangement in the first half and the second half, the deformation amount in the thickness direction of the resin film can be adjusted by deforming the inside of the resin film from both sides of the resin film.

  In the present invention, it is preferable that the resin film is in direct contact with the drive roller and the follower rotating roller. However, as shown in FIG. 2 (d), a film, a sheet, or a belt is interposed between the resin film and the roller. In addition, a method of applying strain deformation in the resin film is also included in the present invention.

<Roller material>
As materials constituting the roller according to the present invention, various commonly known materials can be used. Specifically, it is preferable to combine rollers having different surface hardness or elastic modulus, such as metallic, resin, elastic metal, rubber-coated metal roller, or metal-coated rubber roller.

  In that case, the hard roller surface material is hard chrome-plated, nickel-plated, ceramic super-hard material tungsten-carbide sprayed, etc. It is preferable that the material has good properties and can be polished to a mirror surface.

  The surface roughness is 0.2 s or less, particularly preferably 0.1 s or less.

<Rolling treatment zone>
When the shearing process is to be performed stably, the length of the zone of the rolling process is important. The rolling treatment zone is a zone where a shearing force is applied to the film. The length of the treatment zone is preferably 0.5 mm to 5000 mm, more preferably 3 mm to 3000 mm, and still more preferably 10 mm to 3000 mm. If it is less than 0.5 mm, it is difficult to perform the shearing treatment uniformly, and if it is more than 5000 mm, the equipment becomes large, which is not preferable.

<Roller peripheral speed>
The peripheral speed ratio n of the two calender rollers is preferably in the range of 0.01 to 0.6. Here, n = (V1−V2) / V1, V1, V2: the peripheral speed of the pair of rollers, V1> V2.

  When n is less than 0.01, the tilt angle of the optical axis is not within the required range, and slipping occurs between the rollers, and scratches due to rubbing are likely to occur on the processed film or sheet. On the other hand, if n exceeds 0.6, it is not possible to tilt the optical axis.

<Distance between rollers>
The distance between the two calender rollers is not particularly limited as long as the rolling process necessary to tilt the optical axis can be performed, but the thickness of the film to be manufactured is t (μm), the distance between the rollers is d (μm), the metal belt to be used, etc. When the thickness of the base material is 1 (μm), it is preferably within the range represented by (t-150) ≦ d ≦ (t-20). When the roller interval is less than (t-150), the in-plane retardation of the film becomes unstable, which is not preferable. On the other hand, when the roller interval is larger than (t-20), the light according to the present invention is used. This is not preferable because the axis cannot be inclined.

<Roller linear pressure>
It is preferable that the linear pressure p when nipping with the calender roller is 150 to 1000 [kN / m].

  When the pressing pressure is less than 150 [kN / m], the film cannot be sufficiently pressed, so that the optical axis of the present invention cannot be tilted. On the other hand, the film is pressed with a pressing pressure exceeding 1000 [kN / m]. And the resin film surface is not easily damaged.

<Conveyance tension of resin film>
Here, the transport tension of the resin film means, in the case of the rolling processing apparatus shown in FIG. 3 described later, the tension per cross-sectional area of the film applied to the film being transported from the preheating roll to the first and second rolls, and It refers to the tension per cross-sectional area of the film applied from the first and second rolls to the take-up roll.

  The resin film is preferably subjected to a rolling treatment while transporting tension (T) at 0.4 <T <20 MPa. Preferably 2 <T <15 Mp, more preferably 3 <T <13 MPa.

  Furthermore, it is preferable that the value Q = T / Nz2 obtained by dividing the transport tension T of the resin film by the Nz2 coefficient is controlled in the range of 0.2 <Q <40 with respect to the cycloolefin-based resin film before the rolling treatment. .

<Processing temperature>
In this invention, the aspect which heats or cools the said resin film in the location (it calls a "contact part") where the said resin film and the said 2 types of roller contact, and the contact part is preferable. Strain deformation is likely to occur in the temperature range of 50 ° C above and below the glass transition temperature of the resin film, and heating is performed in front of the contact portion, so that the resin film temperature is close to the glass transition temperature. It is effective to increase the amount. Cooling is carried out after passing through the contact portion, and is effective for maintaining and fixing distortion deformation generated in the film to prevent it from changing.

  In addition, it is not preferable to maintain a temperature state equal to or higher than the glass transition temperature for a long time in a conveyance portion other than the contact portion because the generated strain deformation changes (including the disappearance phenomenon). In addition, in the pre-step of winding up the film after imparting strain deformation, the heat stabilization treatment at a high temperature above the glass transition temperature for a short time (1 to 20 minutes) makes it difficult for the strain deformation to fluctuate for a long time. This is a preferred embodiment.

  The glass transition temperature referred to here is an intermediate value determined according to JIS K7121 (1987) using a differential scanning calorimeter (DSC-7 model manufactured by Perkin Elmer) at a temperature rising rate of 20 ° C./min. The point glass transition temperature (Tmg).

  For the heating, various commonly known heating means such as an electric heater, a far-infrared heater, and a heating medium can be used, and the film can be directly heated (contact and non-contact), the driving roller and the follower rotating roller can be heated. .

  For the cooling, various kinds of generally known cooling means such as cooling with a heat medium, air cooling, and use of a refrigerator can be used, and the film can be directly cooled (contact and non-contact), the driving roller, and the following rotating roller can be cooled. .

  The heating temperature varies depending on the purpose, but is preferably ± 100 ° C. of the glass transition temperature of the resin film. More preferably, it is ± 50 ° C. The cooling temperature is preferably in the range of room temperature to softening point temperature from the viewpoint of handleability.

  FIG. 3 shows a schematic diagram of a rolling processing apparatus using a preheating roller preferable in the present invention.

  In the figure on the right, the feed roller does not have a drive system, followed by a nip roller / heated roller. Each of the first and second rollers is a roller having a drive system, and is a roller capable of arbitrarily controlling the peripheral speed difference. In addition, the pressure between the first and second pressures can be controlled by hydraulic pressure. The take-up roller is a roller having a drive system, and the take-up speed and transport tension are controlled by a tension controller. The preheating roller and the first and second rollers have a heater built in the roller, and a temperature sensor is attached to the roller surface. The sensor temperature is fed back to the heater and temperature controlled with accuracy of ± 1 degree by PID control.

<Cycloolefin resin film>
The cycloolefin resin used in the present invention is made of a polymer resin containing an alicyclic structure.

  A preferred cycloolefin resin is a resin obtained by polymerizing or copolymerizing a cyclic olefin. Examples of the cyclic olefin include norbornene, dicyclopentadiene, tetracyclododecene, ethyltetracyclododecene, ethylidenetetracyclododecene, tetracyclo [7.4.0.110, 13.02,7] trideca-2,4. Unsaturated hydrocarbons of polycyclic structures such as 6,11-tetraene and derivatives thereof; cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene, cyclo Examples thereof include monocyclic unsaturated hydrocarbons such as octene, 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene, cycloheptene, cyclopentadiene, cyclohexadiene, and derivatives thereof. These cyclic olefins may have a polar group as a substituent. Examples of the polar group include a hydroxyl group, a carboxyl group, an alkoxyl group, an epoxy group, a glycidyl group, an oxycarbonyl group, a carbonyl group, an amino group, an ester group, and a carboxylic acid anhydride group. Or a carboxylic anhydride group is preferred.

  A preferable cycloolefin resin may be one obtained by addition copolymerization of a monomer other than the cyclic olefin. Addition copolymerizable monomers include ethylene, propylene, 1-butene, 1-pentene and other ethylene or α-olefins; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl- Examples include dienes such as 1,4-hexadiene and 1,7-octadiene.

The cyclic olefin is obtained by an addition polymerization reaction or a metathesis ring-opening polymerization reaction. The polymerization is carried out in the presence of a catalyst. Examples of the addition polymerization catalyst include a polymerization catalyst composed of a vanadium compound and an organoaluminum compound. As a catalyst for ring-opening polymerization, a polymerization catalyst comprising a metal halide such as ruthenium, rhodium, palladium, osmium, iridium, platinum, nitrate or acetylacetone compound and a reducing agent; or titanium, vanadium, zirconium, tungsten, molybdenum Examples thereof include a polymerization catalyst comprising a metal halide such as acetylacetone compound and an organoaluminum compound. Polymerization temperature, pressure, etc. are not particularly limited, the polymerization temperature of usually -50 ° C. to 100 ° C., are polymerized in the polymerization pressure of 0~490N / cm ^2.

  The cycloolefin resin used in the present invention is preferably a resin obtained by polymerizing or copolymerizing a cyclic olefin and then hydrogenating it so that the unsaturated bond in the molecule is changed to a saturated bond. The hydrogenation reaction is performed by blowing hydrogen in the presence of a known hydrogenation catalyst. Examples of hydrogenation catalysts include cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, transition metal compounds such as titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, tetrabutoxytitanate / dimethylmagnesium / alkyl. Homogeneous catalyst consisting of a combination of metal compounds; heterogeneous metal catalyst such as nickel, palladium, platinum; nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth And a heterogeneous solid-supported catalyst in which a metal catalyst such as palladium / alumina is supported on a carrier.

  Alternatively, examples of the cycloolefin resin include the following norbornene polymers. The norbornene-based polymer preferably has a norbornene skeleton as a repeating unit. Specific examples thereof include JP-A-62-252406, JP-A-62-2252407, and JP-A-2-133413. JP-A-63-145324, JP-A-63-264626, JP-A-1-240517, JP-B-57-8815, JP-A-5-39403, JP-A-5-43663 JP-A-5-43834, JP-A-5-70655, JP-A-5-279554, JP-A-6-206985, JP-A-7-62028, JP-A-8-176411, Although what was described in the Kaihei 9-241484 gazette etc. can be utilized preferably, it is not limited to these. Moreover, these may be used individually by 1 type and may use 2 or more types together.

  In the present invention, among the norbornene-based polymers, those having a repeating unit represented by any of the following structural formulas (I) to (IV) are preferable.

  In the structural formulas (I) to (IV), A, B, C and D each independently represent a hydrogen atom or a monovalent organic group.

  Among the norbornene-based polymers, a polymer obtained by metathesis polymerization of at least one compound represented by the following structural formula (V) or (VI) and an unsaturated cyclic compound copolymerizable therewith. A hydrogenated polymer obtained by hydrogenating is also preferred.

  In the structural formula, A, B, C and D each independently represent a hydrogen atom or a monovalent organic group.

  Here, A, B, C and D are not particularly limited, but preferably an organic group may be linked via a hydrogen atom, a halogen atom, a monovalent organic group, or at least a divalent linking group. These may be the same or different. A or B and C or D may form a monocyclic or polycyclic structure. Here, the at least divalent linking group includes a hetero atom typified by an oxygen atom, a sulfur atom, and a nitrogen atom, and examples thereof include ether, ester, carbonyl, urethane, amide, thioether, and the like. It is not limited. In addition, the organic group may be further substituted via the linking group.

  Examples of other monomers copolymerizable with the norbornene-based monomer include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, C2-C20 alpha olefins, such as 1-hexadecene, 1-octadecene, 1-eicocene, and derivatives thereof; cyclobutene, cyclopentene, cyclohexene, cyclooctene, 3a, 5,6,7a-tetrahydro-4,7 -Cycloolefins such as methano-1H-indene, and derivatives thereof; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene, etc. Conjugated dienes; and the like are used. Among these, an α-olefin, particularly ethylene is preferable.

  These other monomers copolymerizable with the norbornene-based monomer can be used alone or in combination of two or more. In the case of addition copolymerization of a norbornene monomer and another monomer copolymerizable therewith, the ratio of the structural unit derived from the norbornene monomer and the structural unit derived from the other monomer copolymerizable in the addition copolymer However, it is appropriately selected so that the mass ratio is usually 30:70 to 99: 1, preferably 50:50 to 97: 3, more preferably 70:30 to 95: 5.

  When the unsaturated bond remaining in the molecular chain of the synthesized polymer is saturated by a hydrogenation reaction, the hydrogenation rate is 90% or more, preferably 95% or more, particularly from the viewpoint of light resistance deterioration, weather resistance deterioration, etc. Preferably it is 99% or more.

  In addition, examples of the cycloolefin resin used in the present invention include thermoplastic saturated norbornene resins described in paragraph numbers [0014] to [0019] of JP-A-5-2108, and paragraph numbers of JP-A-2001-277430. [0015] to [0031] thermoplastic norbornene polymers, JP 2003-14901 paragraph Nos. [0008] to [0045] thermoplastic norbornene resins, JP 2003-139950 paragraph No. [0014] To [0028] norbornene-based resin composition, Japanese Patent Application Laid-Open No. 2003-161832, paragraph numbers [0029] to [0037], norbornene-based resin, Japanese Patent Application Laid-Open No. 2003-195268, paragraph numbers [0027] to [0036] The norbornene-based resin described in JP 2003-211589 A Paragraph Nos. [0009] to [0023] alicyclic structure-containing polymer resin, norbornene polymer resin or vinyl alicyclic hydrocarbon heavy as described in JP-A-2003-212588, paragraph Nos. [0008] to [0024] Examples include coalesced resins.

  Specifically, ZEONEX, ZEONOR manufactured by Nippon Zeon Co., Ltd., Arton manufactured by JSR Corporation, APPEL manufactured by Mitsui Chemicals, Inc. (APL8008T, APL6509T, APL6013T, APL5014DP, APL6015T) and the like are preferably used.

  The molecular weight of the cycloolefin resin used in the present invention is appropriately selected according to the purpose of use, but is measured by a gel permeation chromatographic method using a cyclohexane solution (or a toluene solution when the polymer resin is not dissolved). When the polyisoprene or polystyrene-equivalent weight average molecular weight is usually in the range of 5,000 to 500,000, preferably 8,000 to 200,000, more preferably 10,000 to 100,000, the mechanical strength and molding processability of the molded body are high. Balanced and suitable.

<Antioxidant>
In addition, when a low-volatile antioxidant is blended at a ratio of 0.01 to 5 parts by mass with respect to 100 parts by mass of the cycloolefin-based resin, the decomposition and coloring of the polymer during the molding process can be effectively prevented. Can do.

  As the antioxidant, compounds described in paragraph numbers [0171] to [0178] of JP-A-2006-301169 are preferably used.

<Hindered amine stabilizer>
By adding a hindered amine stabilizer to the resin, it is possible to highly suppress changes in optical properties such as white turbidity and changes in refractive index when irradiated with light having a short wavelength of 400 nm. The content of the hindered amine stabilizer is preferably 0.05 to 2 parts by mass, and more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the resin.

  Preferable hindered amine stabilizers include compounds described in paragraph No. [0139] of JP-A-2007-216600.

<Antistatic agent>
The cycloolefin-based resin film used in the present invention preferably contains an antistatic agent for rolling, and contains 0.001 to 2.0 parts by mass of the antistatic agent with respect to 100 parts by mass of the resin. Is preferred.

  The antistatic agent is not particularly limited, and known antistatic agents can be used. Among them, anionic antistatic agents, cationic antistatic agents, nonionic antistatic agents, and zwitterionic antistatic agents can be used. Preferably at least one selected from an agent, a polymer antistatic agent and conductive fine particles, more preferably conductive fine particles, particularly preferably cerium oxide, indium oxide, tin oxide, antimony oxide and silicon oxide. At least one selected.

  Examples of the anionic antistatic agent include, for example, Hideo Marumo, “Antistatic Agent, Surface Modification of Polymers”, Koshobo, and augmented “Practical Handbook for Additives for Plastics and Rubbers, p333-p455”, published by Chemical Industry Co., Ltd. No. 256143, JP-B-52-32572, JP-A-10-158484, and the like.

  Examples of the ionic polymer compound include anionic polymer compounds such as those described in JP-B-49-23828, JP-A-49-23827, and JP-A-47-28937; JP-B-55-734, JP-A-50-54672 Ionene type polymers having a dissociating group in the main chain, as shown in JP-B Nos. 59-14735, 57-18175, 57-18176, 57-56059 and the like: JP-B 53-13223 No. 57-15376, No. 53-45231, No. 55-145783, No. 55-65950, No. 55-67746, No. 57-11342, No. 57-19735, No. 58-56858. No., JP-A-61-27853, 62-9346, and a cationic pendant type having a cationic dissociation group in the side chain. Mer, it can be mentioned graft copolymers, such as seen in JP-A-5-230161.

Examples of the conductive fine particles that can be particularly preferably used in the cycloolefin-based resin film include metal oxides such as ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO. BaO, CeO ₂ , Sb ₂ O ₃ , MoO ₂ , V ₂ O ₅ , or a composite oxide thereof is preferable, and CeO ₂ , In ₂ O ₃ , SnO ₂ , Sb ₂ O ₃ , and SiO ₂ are particularly preferable. Is preferred. Examples of containing different atoms include, for example, addition of Al, In, etc. to ZnO, addition of Nb, Ta, etc. to TiO ₂ , and Sb, Nb, halogen elements, etc. to SnO ₂ Is effective. The amount of these different atoms added is preferably in the range of 0.01 to 25 mol%, particularly preferably in the range of 0.1 to 15 mol%.

<Other stabilizers>
One or more stabilizers selected from phenol-based stabilizers, phosphorus-based stabilizers, and sulfur-based stabilizers may be added to the resin. By appropriately selecting these stabilizers and adding them to the resin, it is possible to more highly suppress optical turbidity and white turbidity and refractive index fluctuations when irradiated with light having a short wavelength of 400 nm. .

  Preferable phenol-based stabilizers, phosphorus-based stabilizers, and sulfur-based stabilizers include compounds described in JP-A-2007-216600.

  Although the compounding quantity of these stabilizers is suitably selected in the range which does not impair the objective of this invention, it is 0.01-2 mass parts normally with respect to 100 mass parts of resin, Preferably 0.01-1 mass part It is.

<Plasticizer>
When a norbornene resin is used as the resin, as a plasticizer, bis (2-ethylhexyl) adipate, bis (2-butoxyethyl) adipate, bis (2-ethylhexyl) azelate, dipropylene glycol dibenzoate, citric acid Tri-n-butyl, tri-n-butylacetyl citrate, epoxidized soybean oil, 2-ethylhexyl epoxidized tall oil, chlorinated paraffin, tri-2-ethylhexyl phosphate, tricresyl phosphate, tert-butyl phosphate Phenyl, tri-2-ethylhexyl diphenyl phosphate, dibutyl phthalate, diisohexyl phthalate, diheptyl phthalate, dinonyl phthalate, diundecyl phthalate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, ditridecyl phthalate Known butylbenzyl phthalate, dicyclohexyl phthalate, di-2-ethylhexyl sebacate, tri-2-ethylhexyl trimellitic acid, Santizer 278, Paraplex G40, Drapex 334F, Plastolein 9720, Mesamol, DNODP-610, HB-40, etc. Are applicable. The selection of the plasticizer and the addition amount are appropriately performed on the condition that the resin permeability and resistance to environmental changes are not impaired.

  In the present invention, other resins may be further blended with the above resin. Other resins are added within a range that does not impair the object of the present invention.

  Here, other resins that can be added to the resin are exemplified below.

  (1) A polymer derived from a hydrocarbon having one or two unsaturated bonds, specifically, for example, polyethylene, polypropylene, polymethylbut-1-ene, poly-4-methylpent-1-ene, polybuta Examples include polyolefins such as -1-ene and polystyrene. These polyolefins may have a crosslinked structure.

  (2) Halogen-containing vinyl polymer, specifically, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polychloroprene, chlorinated rubber and the like.

  (3) A polymer derived from an α, β-unsaturated acid and its derivative, specifically, polyacrylate, polymethacrylate, polyacrylamide, polyacrylonitrile, or co-polymerization with the monomer constituting the polymer. Examples thereof include acrylonitrile / butadiene / styrene copolymer, acrylonitrile / styrene copolymer, and acrylonitrile / styrene / acrylic acid ester copolymer.

  (4) Polymers derived from unsaturated alcohols and amines, or acyl derivatives or acetals of unsaturated alcohols, specifically polyvinyl alcohol, polyvinyl acetate, vinyl stearate, polyvinyl benzoate, vinyl polymaleate. , Polyvinyl butyral, polyallyl phthalate, polyallyl melamine, or a copolymer with a monomer constituting the polymer, such as an ethylene / vinyl acetate copolymer.

  (5) A polymer derived from an epoxide, specifically, a polymer derived from polyethylene oxide or bisglycidyl ether.

  (6) Polyacetals, specifically, polyoxymethylene, polyoxyethylene, polyoxymethylene containing ethylene oxide as a comonomer, and the like.

  (7) Polyphenylene oxide (8) Polycarbonate (9) S Polysulfone (10) Polyurethane, urea resin and the like.

  (11) Polyamides and copolyamides derived from diamines and dicarboxylic acids and / or aminocarboxylic acids, or corresponding lactams, and specific examples include nylon 6, nylon 66, nylon 11, nylon 12, and the like.

  (12) Polyesters derived from dicarboxylic acids and dialcohols and / or oxycarboxylic acids, or corresponding lactones, such as polyethylene terephthalate, polybutylene terephthalate, poly 1,4-dimethylol / cyclohexane terephthalate. .

  (13) A polymer having a cross-linked structure derived from aldehyde and phenol, urea or melamine, and specifically includes phenol-formaldehyde resin, urea-formaldehyde resin, melamine-formaldehyde resin and the like.

  (14) Alkyd resin, specifically, glycerin / phthalic acid resin and the like.

  (15) Unsaturated polyester resins and halogen-containing modified resins derived from copolyesters of saturated and unsaturated dicarboxylic acids and polyhydric alcohols and obtained by using vinyl compounds as crosslinking agents.

  (16) Natural polymer, specifically, cellulose, rubber, protein, or derivatives thereof such as cellulose acetate, cellulose propionate, and cellulose ether.

  (17) Soft polymer, for example, a soft polymer containing a cyclic olefin component, an α-olefin copolymer, an α-olefin / diene copolymer, an aromatic vinyl hydrocarbon / conjugated diene soft copolymer And a soft polymer or copolymer comprising isobutylene or isobutylene / conjugated diene.

  (18) Hydrocarbon polymers having an alicyclic ring structure in the side chain are exemplified.

  As a method for mixing the resin binder with other resin components and additives, a method known per se can be applied. For example, a method of mixing each component simultaneously.

<Melt casting method>
There is no particular limitation on the method for forming the cycloolefin-based resin film, and either a heat-melt molding method or a solution casting method can be used. The heat-melt molding method can be further classified into an extrusion molding method, a press molding method, an inflation molding method, an injection molding method, a blow molding method, a stretch molding method, etc. Among these methods, mechanical strength, surface accuracy are included. In order to obtain an excellent film, an extrusion molding method, an inflation molding method, and a press molding method are preferable, and an extrusion molding method is most preferable. The molding conditions are appropriately selected depending on the purpose of use and the molding method. In the case of the hot melt molding method, the cylinder temperature is usually in the range of 150 to 400 ° C, preferably 200 to 350 ° C, more preferably 230 to 330 ° C. Is set as appropriate. If the resin temperature is excessively low, fluidity deteriorates, causing shrinkage or distortion in the film. If the resin temperature is excessively high, voids or silver streaks due to thermal decomposition of the resin may occur, or the film may turn yellow. There is a risk that a molding defect will occur. The thickness of the film is usually in the range of 5 to 300 μm, preferably 10 to 200 μm, more preferably 10 to 100 μm, and particularly preferably 10 to 50 μm.

  The width of the film is preferably 1.4 m or more from the viewpoint of productivity and workability. More preferably, it is the range of 1.4-4m.

  The cycloolefin resin film has a surface wetting tension of preferably 40 mN / m or more, more preferably 50 mN / m or more, and still more preferably 55 mN / m or more. When the surface wetting tension is in the above range, the adhesive strength between the film and the polarizer is improved. In order to adjust the surface wetting tension, for example, corona discharge treatment, plasma discharge treatment, ozone spraying, ultraviolet irradiation, flame treatment, chemical treatment, and other known surface treatments can be performed.

  The sheet before stretching needs to have a thickness of about 10 to 500 μm, and the thickness unevenness is preferably as small as possible. The entire surface is within ± 8%, preferably within ± 6%, more preferably within ± 4%. is there.

  In order to adjust the cycloolefin-based resin film to the retardation value before the rolling treatment described below, the sheet is preferably stretched in a uniaxial direction or a biaxial direction. Substantial uniaxial stretching, for example, biaxial stretching that stretches in a uniaxial direction to orient the molecules after stretching in a range that does not affect the orientation of the molecules may be used. For stretching, a tenter device or the like is preferably used.

  There is no restriction | limiting in particular in a draw ratio, It is 1.1-10 times, Preferably it is 1.3-8 times, What is necessary is just to make it become a desired retardation in this range.

  Stretching is usually performed in a temperature range of Tg to Tg + 50 ° C., preferably Tg to Tg + 40 ° C. of the resin constituting the sheet. If the stretching temperature is too low, it will break, and if it is too high, it will not be molecularly oriented, making it difficult to obtain the desired retardation.

In the present invention, when the refractive index of the cycloolefin-based resin film before the rolling treatment is nx, ny, nz,
(X: film width direction, y: film transport direction, z: film thickness direction)
Retardation value (d represents thickness (nm) of cycloolefin resin film)
Ro2 = (nx−ny) × d is 0 to 90 nm,
Rth2 = ((nx + ny) −nz) / 2 × d is 0.01 to 30 nm,
Nz2 = (nx−nz) / (nx−ny) is 0.5 to 3,
In order to control the retardation value after the rolling treatment to a desired range, it is preferable to adjust to a cycloolefin resin film having a specific retardation value as described above.

  This can be measured at a wavelength of 590 nm in an environment of 23 ° C. and 55% RH using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments).

  The cycloolefin resin film having such optical properties can be obtained by subjecting the material and production method of the cycloolefin resin film described above, particularly the film to stretching treatment.

  The retardation variation is preferably as small as possible, and the retardation film has a retardation variation of 590 nm usually within ± 10 nm, preferably ± 5 nm or less, more preferably ± 1 nm or less.

  The variation and thickness unevenness in the plane of the retardation can be reduced by using such a small unstretched sheet, and by applying a uniform stress to the sheet during stretching. For this purpose, it is desirable to stretch in a controlled temperature environment under a uniform temperature distribution, preferably within ± 5 ° C., more preferably within ± 2 ° C., particularly preferably within ± 0.5 ° C.

  The cycloolefin-based resin film after the rolling treatment has a retardation value Ro1 represented by the following formula (i) in the range of 5 to 35 nm, and a retardation value Rth1 represented by the following formula (ii) is 70 to 150 nm. It is preferable that it is the range of these. These retardation values are measured by the above method.

(I) Ro1 = (na−nb) × d
(Ii) Rth1 = ((na + nb) / 2−nc) × d
(However, the refractive indexes na, nb, and nc are the refractive indexes in the vertical direction of the measurement surface that minimizes the phase difference when measuring the phase difference in the two-component direction of the measurement surface while tilting the film. Where nc is the refractive index in the two-component directions perpendicular to each other on the measurement surface, and na and nb, where each refractive index is a value for light with a wavelength of 590 nm, and d is the film thickness (nm). Represents.)
When the retardation value is in the range, a twisted nematic liquid crystal display device having excellent visibility can be obtained.

<Scattering film>
The scattering film according to the present invention has a scatterer and a transparent resin, and is a film in which the scatterer is dispersed in the transparent resin.

  The scattering film according to the present invention is provided at least on the viewing side of the viewing side polarizing plate. You may provide a scattering film in the visual recognition side and liquid crystal cell side of the polarizer of a visual recognition side polarizing plate. More preferably, the scattering film is provided only on the viewing side of the polarizer of the viewing side polarizing plate. When the scattering film is provided on the outermost surface on the viewing side of the polarizer of the viewing side polarizing plate, it can be used together with the antiglare film.

  The scattering film is preferably a film having a thickness of 20 μm to 90 μm, and more preferably a film having a thickness of 20 μm to 65 μm. In order to obtain a sufficient scattering effect, the thickness of the scattering film is preferably 2.0 times or more the particle size of the scatterer.

  Moreover, it is preferable that a scattering film contains 1-25 mass parts of scatterers with respect to 100 mass parts of scattering films.

  The scattering film may be produced by either a solution casting method in which a dope liquid containing the following materials is prepared and cast on a support, or a melt casting method in which pellets are prepared and melt extruded.

<Scatterer>
In order to obtain a scattering effect, the scatterer needs to be a particle having a refractive index different from that of the transparent resin. In particular, the scatterer is preferably a particle having a refractive index difference of 0.02 or more from the transparent resin. More preferably, the particle has a refractive index difference of 0.05 or more with the transparent resin. As the difference in refractive index is larger, the scattering efficiency can be improved. Further, the refractive index of the scatterer may be larger or smaller than the refractive index of the transparent resin. When the refractive index of the scatterer is larger than the refractive index of the transparent resin, the intensity of forward scattering can be increased, and when it is smaller, the scattering spread angle can be increased.

  The scatterer is preferably a particle having a volume average particle diameter of 1.0 to 7.0 μm, and more preferably a particle having a volume average particle diameter of 1.5 to 6.0 μm. By adjusting the particle diameter, it is possible to obtain an angular distribution of light scattering. However, in order to maintain the front brightness in terms of display quality, it is necessary to increase the transmittance as much as possible. When the particle diameter is less than 1.0 μm, the effect of scattering is great and the viewing angle characteristics are dramatically improved, but the backscattering becomes large and the brightness is drastically reduced. On the other hand, when it exceeds 7.0 μm, the scattering effect is small, and the improvement in viewing angle characteristics is small.

  When the particle size of the scatterer is in the range of 1.0 to 7.0 μm, the particle size of the scatterer is sufficiently large compared to the wavelength of visible light, and therefore individual scattering within the scattering film is well known. Can be described approximately by the Mie scattering theory.

  As the scatterer, it is preferable to use translucent fine particles. The translucent fine particles are not particularly limited, but are preferably translucent resin particles with high transparency, and more preferably silicone resins. The shape of the scatterer is preferably spherical.

  Examples of silicone resins include spherical silica fine particles. For example, high purity synthetic spherical silica SO series made by Admatechs, Excellica series fine cut grade UF series made by Tokuyama Co., Ltd. Fine cut of spherical silica made by Tatsumori Co., Ltd. Grade, Momentive Performance Materials Japan Tospearl series, Nippon Shokubai KEP series, etc. can be used.

<Transparent resin>
As a transparent resin used for a scattering film, it is mentioned that it is easy to manufacture, is optically isotropic, and is optically transparent.

  The term “transparent” as used in the present invention means that the visible light transmittance is 60% or more, preferably 80% or more, and particularly preferably 90% or more.

  Although it does not specifically limit if it has said property, For example, polyesters, such as a cellulose ester, polyester, a polycarbonate, a polyarylate, a polysulfone (a polyether sulfone is also included), a polyethylene terephthalate, a polyethylene naphthalate, polyethylene, a polypropylene, Cellophane, polyvinylidene chloride, polyvinyl alcohol derivative, cycloolefin polymer (Arton (manufactured by JSR), Zeonex, Zeonore (manufactured by Nippon Zeon)), polymethylpentene, polyether ketone, polyether ketone imide, polyamide, fluorine Examples thereof include acrylic derivatives such as resin, nylon and polymethyl methacrylate, and acrylic. As the transparent resin according to the present invention, it is preferable to use a cellulose ester that can be directly bonded to a polarizer by a saponification treatment or a material obtained by blending an acrylic resin and a cellulose ester resin.

<Other additives>
The scattering film can contain a plasticizer, an acrylic resin, an ultraviolet absorber, particles, various polymers, and the like as necessary.

<Polarizing plate>
A method for manufacturing the polarizing plate is not particularly limited, and the polarizing plate can be manufactured by a general method. The obtained retardation film uses an adhesive such as an acrylic pressure-sensitive adhesive on at least one polarizing plate protective film surface of a polarizing plate having a polarizer prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution. And paste. The polarizing plate protective film is not particularly limited, but a cellulose ester resin film such as a TAC film is usually used.

  Further, the scattering film is similarly bonded to the opposite surface of the polarizer. If the scattering film is a film using a cellulose ester-based resin, it can be directly bonded to a polarizer by using a completely saponified PVA aqueous solution or the like by saponification treatment, which can serve as a polarizing plate protective film and is advantageous for thinning. .

  The above retardation film is preferably bonded in the same manner for the polarizing plate mounted on the other surface with the liquid crystal cell interposed therebetween. A scattering film according to the present invention may be used on the surface opposite to the retardation film across the polarizer, and as a conventional polarizing plate protective film, Konica Minoltack KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, It is also preferable to use a cellulose ester resin film such as KC8UCR-3, KC8UCR-4, KC12UR, KC8UXW-H, KC8UYW-HA, KC8UX-RHA (manufactured by Konica Minolta Opto).

  Moreover, about the bonding of retardation film, you may perform an easily bonding process as described in Unexamined-Japanese-Patent No. 6-94915 and 6-118232, and may perform a polarizing plate process.

<Display device>
<TN liquid crystal display device>
A TN liquid crystal display device in which the retardation film according to the present invention is used will be described.

  The configuration of the TN type liquid crystal display device is not particularly limited. Further, a light source may be further provided, and the light source is not particularly limited. However, for example, a planar light source that emits polarized light is preferable because light energy can be used effectively.

  An example of a TN liquid crystal display device in which the retardation film is particularly preferably used will be described with reference to FIGS. Each of the first polarizing plate 13 and the second polarizing plate 15 has a structure in which the polarizers 2 and 10 are sandwiched between two polarizing plate protective films (the polarizer 2 includes the first polarizing plate protective film 1 and the second polarizing plate 1). The polarizer 10 is sandwiched between the third polarizer protective film 9 and the fourth polarizer protective film 11.

  The TN liquid crystal cell 14 has a liquid crystal layer 6 in a space sandwiched between two glass cell substrates 4 and 8. The average thickness of the liquid crystal layer 6 is the liquid crystal cell gap.

  The glass cell substrates 4 and 8 are provided with alignment layers 5 and 7 for aligning liquid crystals, and the alignment layers are rubbed. The twist angle of the liquid crystal coincides with the direction of the opposing rubbing process, that is, the angle formed by the rubbing axis, and the angle formed by the rubbing axis of the alignment layer 5 (reference 0 °) and the rubbing axis of the alignment layer 7 is 115 ± 22. °.

  The angle formed by the transmission axis of the first polarizing plate 13 (equal to the transmission axis of the polarizer 2) and the rubbing axis of the liquid crystal alignment layer 5 is 3.5 ± 3 °, and the transmission axis of the second polarizing plate 15 The angle formed by (the same as the transmission axis of the polarizer 10) and the rubbing axis of the liquid crystal alignment layer 7 is 3.5 ± 3 °.

  Note that the first polarizing plate and the second polarizing plate are arranged so as to be crossed Nicols (the transmission axes of each other form 90 °).

  Although the retardation film of the present invention is not shown, it is between the second polarizing plate protective film 3 and the glass cell substrate 4 of FIG. 4 and between the third polarizing plate protective film 9 and the glass cell substrate 8 through an adhesive. It is preferable to be bonded to two places (both sides of the liquid crystal cell).

  The scattering film of the present invention may be bonded to the first polarizing plate protective film 1 or may also serve as the first polarizing plate protective film 1.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
<Preparation of cycloolefin resin film 1>
A cycloolefin-based resin film stretched in the width direction was produced as follows.

  In a nitrogen atmosphere, 500 parts of dehydrated cyclohexane, 1.2 parts of 1-hexene, 0.15 part of dibutyl ether, and 0.30 part of triisobutylaluminum were mixed in a reactor at room temperature, and then kept at 45 ° C. 20 parts of tricyclo [4.3.0.12,5] deca-3,7-diene (dicyclopentadiene, hereinafter abbreviated as DCP), 1,4-methano-1,4,4a, 9a-tetrahydrofluorene ( Hereinafter, a norbornene-based monomer comprising 140 parts of MTF) and 40 parts of 8-methyl-tetracyclo [4.4.0.12, 5.17,10] -dodec-3-ene (hereinafter abbreviated as MTD). The mixture and 40 parts of tungsten hexachloride (0.7% toluene solution) were continuously added over 2 hours for polymerization. To the polymerization solution, 1.06 part of butyl glycidyl ether and 0.52 part of isopropyl alcohol were added to deactivate the polymerization catalyst and stop the polymerization reaction.

  Next, 270 parts of cyclohexane is added to 100 parts of the reaction solution containing the obtained ring-opening polymer, and further 5 parts of a nickel-alumina catalyst (manufactured by JGC Chemical Co., Ltd.) is added as a hydrogenation catalyst. The mixture was heated to 200 ° C. while being pressurized and stirred, and then reacted for 4 hours to obtain a reaction solution containing 20% of a DCP / MTF / MTD ring-opening polymer hydrogenated polymer. After removing the hydrogenation catalyst by filtration, a soft polymer (manufactured by Kuraray; Septon 2002) and an antioxidant (manufactured by Ciba Japan; Irganox 1010) are added and dissolved in the obtained solutions. (Both 0.1 parts per 100 parts polymer). Next, cyclohexane and other volatile components, which are solvents, are removed from the solution using a cylindrical concentration dryer (manufactured by Hitachi, Ltd.), the hydrogenated polymer is extruded in a strand form from an extruder in a molten state, and pellets after cooling. And recovered. When the copolymerization ratio of each norbornene monomer in the polymer was calculated from the composition of the residual norbornenes in the solution after polymerization (by gas chromatography method), it was almost charged at DCP / MTF / MTD = 10/70/20. It was equal to the composition. This hydrogenated ring-opened polymer had a weight average molecular weight (Mw) of 31,000, a molecular weight distribution (Mw / Mn) of 2.5, a hydrogenation rate of 99.9%, and a Tg of 134 ° C.

  The obtained pellets of the ring-opened polymer hydrogenated product were dried at 70 ° C. for 2 hours using a hot air dryer in which air was circulated to remove moisture. Next, the pellets were subjected to a short shaft extruder having a coat hanger type T die having a lip width of 1400 mm (manufactured by Mitsubishi Heavy Industries, Ltd .: screw diameter 90 mm, T die lip material is tungsten carbide, peel strength 44N from molten resin). It was used for melt extrusion molding to produce a cycloolefin resin film 1 having a thickness of 50 μm. Extrusion molding was performed in a clean room of class 10,000 or less under molding conditions of a molten resin temperature of 240 ° C. and a T die temperature of 240 ° C. The resulting film was stretched 1.50 times in the width direction at a stretching temperature of 155 ° C. using a tenter device in the middle of the drying process, and the resulting 100 μm-thick cycloolefin resin film slit both ears. And processed to a width of 1.5 m. Moreover, the polyester film was wound up together as a protective film when winding up.

  As a result of measuring the retardation value of the obtained sample in the following manner, Ro2 = 10 nm, Rth2 = 50 nm, and Nz2 = 5.5.

(Measurement of retardation Ro2, Rth2, Nz2)
A 35 mm × 35 mm sample was cut out from the obtained film, conditioned at 25 ° C. and 55% RH for 2 hours, and the retardation was measured at 590 nm with an automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.).

Ro2 = (nx−ny) × d
Rth2 = ((nx + ny) −nz) / 2 × d
Nz2 = (nx-nz) / (nx-ny)
(Refractive index of cycloolefin resin film is nx, ny, nz (x: film width direction, y: film transport direction, z: film thickness direction), d is cycloolefin resin film thickness (nm) Represents)
<Preparation of polycarbonate film 1>
In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 152400 parts of ion-exchanged water and 84320 parts of 25% aqueous sodium hydroxide solution were added, and 9,9-bis (4-hydroxy-3 having a purity of 99.8% by HPLC analysis. -Methylphenyl) fluorene (hereinafter sometimes abbreviated as “biscresol fluorene”) 34848 parts, 2,2-bis (4-hydroxyphenyl) propane 9008 parts (hereinafter sometimes abbreviated as “bisphenol A”) and After dissolving 88 parts of hydrosulfite, 178400 parts of methylene chloride was added, and 18248 parts of phosgene was blown in at 60 ° C. for 15 minutes at 15-25 ° C. with stirring. After completion of the phosgene blowing, a solution obtained by dissolving 177.8 parts of p-tert-butylphenol in 2640 parts of methylene chloride and 10560 parts of a 25% aqueous sodium hydroxide solution were added. The reaction was terminated by stirring for a period of time. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and when the conductivity of the aqueous phase is almost the same as that of ion-exchanged water, the methylene chloride phase is concentrated and dehydrated to remove polycarbonate. A solution with a concentration of 20% was obtained. The polycarbonate (copolymer A) obtained by removing the solvent from this solution had a molar ratio of biscresol fluorene to bisphenol A of 70:30 (polymer yield 97%). In addition, this polymer had an intrinsic viscosity of 0.674 and a Tg of 226 ° C.

  To 75 parts by mass of a mixed solvent of methylene chloride and ethanol containing 4 parts by mass of ethanol, 25 parts by mass of the polycarbonate was dissolved while stirring at 25 ° C. to obtain a transparent and viscous dope. The dope was cast on a 100 m stainless steel belt, which was blown with dry air and the dew point was controlled to 12 ° C. or less, and was peeled off. The residual solvent concentration at that time was 35%. From the fact that the peelability was good and the charge was small, no peeling step or peeling streaks were observed on the film surface by visual observation. Thereafter, when the residual solvent concentration was 2%, the width was maintained and dried. Then, it dried until the residual solvent density | concentration became 1% or less, and obtained the aromatic polycarbonate film 1 with a film thickness of 100 micrometers. Ro2 = 30 nm, Rth = 0.1 nm, and Nz2 = 0.5.

<Preparation of retardation film 101>
Next, the cycloolefin-based resin film 1 obtained above is sandwiched between rollers R ₄ and R ₅ having different peripheral speeds shown in FIG. 3 according to the method disclosed in JP-A-6-222213. A retardation film 101 was prepared in a roll shape of 50 m.

In FIG. 3, a roller R ₁ is a feed roller, and R ₂ and R ₃ are nip rollers and residual heat rollers having no drive system. R ₄ and R ₅ are rollers each having a drive system, and are rollers capable of arbitrarily controlling the peripheral speed difference. In addition, the pressure between R ₄ and R ₅ can be controlled by hydraulic pressure. R ₆ is a winding roller having a drive system, and the winding speed is controlled by a tension controller. The R _{2 to} R ₅ rollers have a built-in heater, and a temperature sensor is attached to the roller surface. The temperature from the temperature sensor is fed back to the heater, and the temperature is controlled with accuracy of ± 1 ° C by PID control. is doing.

  The conditions for the rolling process are as follows.

Preheating rollers R2, R3 diameter: 150mm
Preheating rollers R2 and R3 speed: 2.00 m / min
Preheating rollers R2, R3 temperature: 150 ° C
Diameter of roller R ₄ and roller R ₅ : 150 mm
Surface roughness Ra of roller R ₄ and roller R ₅ : 0.05S
Circumferential speed of roller R ₄ and roller R ₅ : 2.00 m / min, 0.08 m / min
Peripheral speed ratio of roller R ₄ and roller R ₅ : 0.04
Surface temperature of roller R ₄ and roller R ₅ : 140 ° C.
Linear pressure applied to the film sandwiched between the rollers R ₄ and R ₅ : 250 [kN / m]
Film transport tension T: 8.0 MPa
Q = T / Nz2: 1.5
About the obtained film, the following inclination-angle (alpha) and retardation were measured.

The inclination angle α from the film normal direction of the refractive index nc is 30 °,
Ro1 = (na−nb) × d is 14 nm,
Rth1 = ((na + nb) −nc) / 2 × d is 117 nm,
Nz1 = (na-nc) / (na-nb) was 6.5.

  However, the refractive indexes na, nb, and nc indicate the refractive index in the vertical direction of the measurement surface that minimizes the phase difference when measuring the phase difference in the two-component direction of the measurement surface while tilting the film. Let nc be the refractive indices of the two component directions orthogonal to each other on the measurement surface. d is the thickness (nm) of the film. The measurement was carried out at 590 nm with an automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.) in an environment of 25 ° C. and 55% RH.

  Further, the variation αα of the angle α (the difference between the maximum value and the minimum value when a size of 15 cm × 60 cm is cut out from the produced retardation film and the 36-point tilt angle α is measured from the same) is 0. It was .01 °.

  The variation ΔRo1 of the retardation value Ro1 (the amount of change in the retardation value Ro1 between the distances of 1 cm of the optical compensation film) was 0.0006.

<Preparation of retardation film 102>
Using the polycarbonate film 1 produced as described above, a retardation film 102 was produced by rolling in the same manner as the retardation film 101.

The inclination angle α from the film normal direction of the refractive index nc is 50 °,
Ro1 = (na−nb) × d is 70 nm,
Rth1 = ((na + nb) −nc) / 2 × d is 245 nm,
Nz1 = (na-nc) / (na-nb) was 4.0.

  The variation Δα in the inclination angle α was 0.10 °, and the variation was large.

  The variation ΔRo1 of the retardation value Ro1 was 0.0080, and the variation was large.

<Preparation of retardation film 103>
According to Example 1 of JP-A-2002-156527, a retardation film 103 in which an optically anisotropic layer containing a liquid crystal compound was provided on a TAC film via an alignment film was produced.

The inclination angle α from the film normal direction of the refractive index nc is 40 °,
Ro1 = (na−nb) × d is 25 nm,
Rth1 = ((na + nb) −nc) / 2 × d is 162.5 nm,
Nz1 = (na-nc) / (na-nb) was 7.0.

  The variation Δα in the inclination angle α was 0.30 °, and the variation was large.

  The variation ΔRo1 of the retardation value Ro1 was 0.0010, and the variation was slightly large.

<Preparation of scattering film A>
(Dope solution composition)
Cellulose ester (cellulose triacetate (degree of acetylation: 61.5%, Mn: 110000, Mw / Mn = 2.0, refractive index 1.48) 100 parts by weight Trimethylolpropane tribenzoate 4.5 parts by weight ethylphthalylethyl Glycolate 5 parts by weight Methylene chloride 430 parts by weight Ethanol 40 parts by weight Spherical particle S1 10 parts by weight The above composition was sufficiently stirred while heating to dissolve the resin and disperse the particles to prepare a dope solution.

[Production of Spherical Particle S1]
The following spherical particles S1 (refractive index: 1.43) were produced by the method described in the reference (Japanese Patent Laid-Open No. 63-77940).

S1: True spherical polymethylsilsesquioxane particles, average particle size 1.0 μm
(Making of scattering film)
The produced dope solution was uniformly cast on a stainless steel band support at a temperature of 22 ° C. and a width of 2 m using a belt casting apparatus. With the stainless steel band support, the solvent was evaporated until the residual solvent amount reached 100%, and the film was peeled off from the stainless steel band support with a peeling tension of 162 N / m.

  The web of the peeled scattering film was evaporated at 35 ° C., slit to 1.6 m width, and then dried at a drying temperature of 135 ° C. while being stretched 1.1 times in the width direction by a tenter. At this time, the residual solvent amount when starting stretching with a tenter was 10%.

  After stretching with a tenter, relaxation was performed at 130 ° C. for 5 minutes, and then drying was completed while transporting a drying zone at 120 ° C. and 140 ° C. with many rolls, slitting to a width of 1.5 m, and a width of 10 mm at both ends of the film A knurling process having a height of 5 μm was performed, and the film was wound around a core having an inner diameter of 15.24 cm with an initial tension of 220 N / m and a final tension of 110 N / m to obtain a scattering film A having a thickness of 40 μm.

<< Preparation of polarizing plate for viewing side >>
Next, a polarizing plate was prepared using each of the retardation films 101 to 103, the scattering film A, and a TAC film (Konica Minolta Op KC4UY manufactured by Konica Minolta Opto).

  A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizer.

  Next, according to the following steps 1 to 5, the TAC film and the retardation films 101 to 103 are bonded to the liquid crystal cell side of the polarizer, and the scattering film A or the TAC film is bonded to the viewing side of the polarizer in the configuration shown in Table 1 to be polarized. Plates 101-103 were produced.

  The polarizer, the retardation film, the scattering film A, and the TAC film were bonded by the following process.

  Step 1: The scattering film A and the TAC film were immersed in a 1 mol / L sodium hydroxide solution at 50 ° C. for 60 seconds, then washed with water and dried to saponify the side to be bonded to the polarizer.

  Process 2: The said polarizer was immersed in the polyvinyl alcohol adhesive tank of 2 mass% of solid content for 1-2 seconds.

  Step 3: Excess adhesive adhered to the polarizer in Step 2 was gently wiped off, and the polarizer was sandwiched between the scattering film A and TAC film processed in Step 1 and placed.

Step 4: The TAC film, the polarizer and the scattering film A laminated in Step 3 were bonded at a pressure of 20 to 30 N / cm ² and a conveyance speed of about 2 m / min.

  Process 5: The sample which bonded the TAC film produced in the process 4, the polarizer, and the scattering film A in the 80 degreeC dryer was dried for 2 minutes, and the polarizing plate was produced.

  Next, retardation films 101 to 103 were bonded on the TAC film surface using an acrylic pressure-sensitive adhesive to produce viewing side polarizing plates 101 to 103.

  In addition, when laminating the retardation film 103, the liquid crystal coating layer was laminated and adhered so that it was on the outside.

<Production of liquid crystal cell and liquid crystal display device>
A polyimide alignment film was provided on a glass substrate on which an ITO transparent electrode was provided, and a rubbing treatment was performed. The two substrates were stacked with the alignment film facing each other through a 4.3 μm spacer. The two substrates were arranged so that the rubbing directions of the alignment films were orthogonal. Rod-like liquid crystalline molecules (ZLI-4792, manufactured by Merck & Co., Inc.) are injected into the gap between the substrates, and the viewing side polarizing plates 101 to 103 are placed on both sides of the TN liquid crystal cell produced as described above. The liquid crystal display devices 101 to 103 were manufactured by sticking each using an adhesive. A rectangular wave voltage of 55 Hz is applied to the liquid crystal cell of the liquid crystal display device, and the contrast ratio of 10 at the top, bottom, left, and right is defined as the contrast ratio of white display and black display at 1.6 V for white display and 4.8 V for black display. The viewing angle at which 20 was obtained was measured. In addition, the polarizing plate was bonded to the liquid crystal cell so that the rubbing axis of the substrate on which the polarizing plate was bonded and the absorption axis of the polarizing plate were matched.

<Evaluation>
The viewing angle measurement was performed using EZ-contrast 160R manufactured by ELDIM. The luminance ratio of white and black in the front was used as the front contrast, and the angle of the contrast ratio 10: 1 was used as the viewing angle. Moreover, the practical evaluation evaluated visually by displaying the following.
(Viewing angle)
TN viewing angle evaluation criteria:
A: Improved by 30 ° or more each on the left and right compared with the following commercially available TN ○: Improved 15 ° or more on each of the left and right compared with the following commercially available TN Δ: Improved by 10 ° or more on each of the left and right compared with the following commercially available TN ×: No improvement compared with the following commercially available TN Viewing angle of a commercially available TN type liquid crystal display device:
Viewing angle Up / Down Left / Right Inverted Left / Right TN 27 ° 60 ° 45 ° × 2 40 °
(Practical evaluation)
(1) Halftone inversion of image ◎: Almost no inversion is recognized ○: Inversion is slightly recognized, but I do not care △: Minor inversion is recognized and I am interested ×: Inversion is visible and practically problematic (2) Black Crushing ◎: Black is not crushed and clear ○: Black is not crushed but clear △: Black is not crushed but sharpness is low ×: Black is crushed and sharpness is low The display screen was visually observed from the horizontal direction of 45 °.

◎: Color change is not seen ○: Color change is slightly recognized but I am not interested △: Minor color change is recognized and I am interested ×: Color change is clearly known and practically problematic It is shown in 1.

  From Table 1, the liquid crystal display device 101 equipped with the polarizing plate 101 using the cycloolefin-based resin film which is the retardation film of the present invention and the scattering film A has a viewing angle, a white color change, and a comparative example. It was found that it improved.

Example 2
In the production of the retardation film 101, the retardation film 201 is similarly changed except that the stretching conditions are changed to change the optical property values before the rolling treatment as shown in Table 2 and the rolling treatment conditions are changed as shown in Table 2. To 208, and polarizing plates 201 to 208 and liquid crystal display devices 201 to 208 were manufactured in the same manner as the polarizing plate 101 and the liquid crystal display device 101.

  Using the obtained liquid crystal display device, the same evaluation as in Example 1 was performed, and the results are shown in Table 3.

  From Tables 2 and 3, it was found that the liquid crystal display device having the configuration of the present invention was improved in view angle, halftone inversion, blackening, and white color change over the comparative example.

Example 3
Scattering films B to E were prepared using the following particles S2 to S5 instead of the spherical particles S1 of Example 1, and the polarizing plates 301 to 101 were formed in the same manner as the polarizing plate 101 and the liquid crystal display device 101 of Example 1. 304 and liquid crystal display devices 301 to 304 were produced.

(Production of spherical particles)
The following spherical particles S2 to S5 (refractive index 1.43) were prepared by the method described in the reference (Japanese Patent Laid-Open No. 63-77940).

S2: Spherical polymethylsilsesquioxane particles, average particle size 3.0 μm
S3: True spherical polymethylsilsesquioxane particles, average particle size 4.5 μm
S4: True spherical polymethylsilsesquioxane particles, average particle size 6.0 μm
S5: Spherical polymethylsilsesquioxane particles, average particle size 7.0 μm
Using the obtained liquid crystal display device, the same evaluation as in Example 1 was performed, and the results are shown in Table 4.

  From Table 4, when the particle size of the particles used for the scattering film is in the range of 1.0 to 7.0 μm, the viewing angle of the liquid crystal display device, halftone inversion, blackening, and white color change are further improved. I found out that

1,1R Driving roller 2R Following rotation roller B Belt F Resin film 1 First polarizing plate protective film 2 First polarizer (3.5 ± 3 ° having transmission axis)
3 Second polarizing plate protective film 4 Viewing side glass cell substrate 5 Viewing side liquid crystal alignment layer (having a rubbing axis reference 0 °)
6 Liquid crystal layer (d: Liquid crystal cell gap)
7 Backlight side liquid crystal alignment layer (having rubbing axis 115 ± 22 °)
8 Backlight side glass cell substrate 9 Third polarizing plate protective film 10 Second polarizer (having transmission axis 93.5 ± 3 °)
11 4th polarizing plate protective film 13 1st polarizing plate 14 TN system liquid crystal cell 15 2nd polarizing plate 16 Transmission axis (3.5 ± 3 degrees) of 1st polarizing plate
17 Rubbing axis of viewing side liquid crystal alignment layer (reference 0 °)
18 Back rubbing axis of the liquid crystal alignment layer (115 ± 22 °)
19 Transmission axis of second polarizing plate (93.5 ± 3 °)
R ₁ feed roller R ₂ preheating roller 1
R ₃ preheating roller 2
R ₄ first roller R ₅ second roller R ₆ take-up roller

Claims (4)

Twisted nematic liquid crystal cell, first polarizer provided on the viewing side of the liquid crystal cell, twisted nematic liquid crystal display having a second polarizer and a backlight unit provided on the backlight side of the liquid crystal cell In the device
When at least one of the liquid crystal cell and the first polarizer and at least one of the liquid crystal cell and the second polarizer has a refractive index in three directions of na, nb, and nc, na ≧ nb> nc, and has a cycloolefin resin film in which the angle α from the normal direction of the film surface of the refractive index nc is inclined by 5 to 50 °, and at least on the viewing side of the first polarizer A twisted nematic liquid crystal display device comprising a scattering film in which a scatterer is dispersed in a transparent resin.
(However, the refractive indexes na, nb, and nc are the refractive indexes in the vertical direction of the measurement surface that minimizes the phase difference when measuring the phase difference in the two-component direction of the measurement surface while tilting the film. Is nc, and the refractive indices in the two-component directions orthogonal to each other on the measurement surface are na and nb.) The cycloolefin-based resin film is stretched, and Ro1 represented by the following formula (i) is in the range of 5 to 35 nm, and Rth1 represented by the following formula (ii) is in the range of 70 to 150 nm. The twisted nematic type liquid crystal display device according to claim 1.
(I) Ro1 = (na−nb) × d
(Ii) Rth1 = ((na + nb) / 2−nc) × d
(However, the refractive indexes na, nb, and nc are the refractive indexes in the vertical direction of the measurement surface that minimizes the phase difference when measuring the phase difference in the two-component direction of the measurement surface while tilting the film. Where nc is the refractive index in the two-component directions perpendicular to each other on the measurement surface, and na and nb, where each refractive index is a value for light with a wavelength of 590 nm, and d is the film thickness (nm). Represents.)   The scatterer contained in the scattering film is a particle having a volume average particle diameter of 1.0 to 7.0 μm, and a difference in refractive index between the transparent resin and the scatterer is 0.02 or more. The twisted nematic liquid crystal display device according to claim 1. A method for producing a cycloolefin-based resin film according to claim 1 or 2,
When the refractive index for light with a wavelength of 590 nm of the cycloolefin-based resin film before rolling is nx, ny, nz, (x: film width direction, y: film transport direction, z: film thickness direction) )
Retardation value (d represents thickness (nm) of cycloolefin resin film)
Ro2 = (nx−ny) × d is 0 to 90 nm,
Rth2 = ((nx + ny) −nz) / 2 × d is 0.01 to 30 nm,
Nz2 = (nx−nz) / (nx−ny) is 0.5 to 3,
A cycloolefin-based resin film,
Using at least one pair of calendar rollers,
While conveying the film transport tension (T) at 0.4 <T <20 MPa,
The linear pressure p when nipping with the calender roller is 150 to 1000 [kN / m],
The peripheral speed ratio n of the two rollers of the calendar roller is 0.01 to 0.6,
(Where n = (V1-V2) / V1 V1, V2: peripheral speed of a pair of rollers, V1> V2)
A method for producing a cycloolefin-based resin film, wherein a rolling treatment is performed while a value Q = T / Nz2 obtained by dividing the film transport tension T by an Nz2 coefficient is adjusted to a range of 0.2 <Q <40.

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