JP2006291163A - Film, production method therefor and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic film having excellent heat resistance, optical properties, mechanical properties and a small coefficient of linear thermal expansion. <P>SOLUTION: The film is characterized by having ≥250°C glass transition temperature (Tg), -20 to 40 ppm/°C coefficient of linear thermal expansion measured in the range of 25-250°C and ≥70% light transmittance at 420 nm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel film excellent in heat resistance, optical properties, and mechanical properties, a method for producing the same, and an image display device using the film.

  Inorganic glass materials are widely used as transparent materials because they are excellent in transparency and heat resistance and have small optical anisotropy. However, since inorganic glass has a large specific gravity and is brittle, a molded glass product is heavy and has a defect such as being easily damaged. Due to such drawbacks, in recent years, development of plastic materials that replace inorganic glass materials has been actively conducted.

  As plastic materials for the purpose of replacing such inorganic glass materials, for example, polymethyl methacrylate, polycarbonate, polyethylene terephthalate and the like are known. Since these plastic materials are lightweight, excellent in mechanical properties, and excellent in processability, these plastic materials are recently used in various applications such as lenses and films.

  Also in the field of flat panel displays such as liquid crystal display devices and organic EL display devices, the need for improved breakage resistance, weight reduction, and thinning is increasing. Has been. Since a plastic film substrate can be a flexible substrate, it can be used as a substrate for a mobile information communication device display device such as a portable information terminal such as a mobile phone, an electronic notebook, or a laptop personal computer, and therefore has a particularly high need.

Examples of heat-resistant plastics used for the above purpose include heat-resistant amorphous polymers such as modified polycarbonate (modified PC: see, for example, Patent Document 1), polyethersulfone (PES: see, for example, Patent Document 2). A cycloolefin copolymer (see, for example, Patent Document 3) is known.
However, there is a problem that sufficient heat resistance as a plastic film substrate cannot be obtained even if these heat-resistant plastics are used. That is, when a conductive layer is formed on a plastic substrate using these heat-resistant plastics and then exposed to a temperature of 150 ° C. or higher in order to provide an alignment film or the like, there is a problem that the conductivity and gas barrier properties are greatly reduced. there were. Further, since further heat resistance is required when installing TFTs for the production of an active matrix image element, it has been desired to provide a plastic substrate having further excellent heat resistance.

  So far, a polyarylate film having a fluorene structure in the main chain has been proposed as a heat-resistant optical film (see, for example, Patent Document 4). However, since this film has a large coefficient of linear thermal expansion (CTE) in the film plane, cracks occur in the inorganic layer due to thermal expansion in the TFT installation process, and the TFT characteristics are not sufficient to obtain sufficient TFT characteristics. Has the problem.

  On the other hand, as a technique for reducing the linear thermal expansion coefficient of a transparent resin, there is a press stretching method (for example, see Non-Patent Document 1). However, the press stretching method is applied to polymers having low heat resistance such as PMMA and PC, and is not used for polymers having high heat resistance. Also, ordinary roll stretching methods and tenter stretching methods are not used for polymers having high heat resistance.

For these reasons, it has been strongly desired to develop a plastic film having high heat resistance, sufficiently satisfying required performance such as mechanical characteristics and optical characteristics, and having a small linear thermal expansion coefficient.
JP 2000-227603 A (Claim 7, [0009] to [0019]) JP 2000-284717 A ([0010], [0021] to [0027]) JP 2001-150584 A ([0027] to [0039]) JP-A-3-28222 Proceedings of the 53rd Annual Meeting of the Society of Polymer Science, Japan, page 779

  The present invention has been made to solve the problems of conventional plastic materials, and an object of the present invention is to provide a plastic film having excellent heat resistance, optical properties and mechanical properties, and having a small linear thermal expansion coefficient. It is in providing the manufacturing method. Another object of the present invention is to provide an image display device using the film and having excellent display quality.

［一般式（１）および（２）中、環αおよび環βは、それぞれ独立に単環式または多環式の環を表し、１つの４級炭素によって連結している。一般式（１）中、連結基は環αの任意の２つの炭素と結合している。一般式（２）中、連結基は環αの任意の１つの炭素と環βの任意の１つの炭素と結合している。一般式（３）中、２つの環γおよび環δは、それぞれ独立に単環式または多環式の環を表し、環δ上の１つの４級炭素に連結される。連結基は環γの任意の炭素と結合している。］ As a result of intensive studies, the present inventors have found that the present invention having the following configuration can solve the problems.
[1] The glass transition temperature (Tg) is 250 ° C. or higher, the linear thermal expansion coefficient in the measurement range from 25 ° C. to 250 ° C. is −20 to 40 ppm / ° C., and the light transmittance at 420 nm is 70% or higher. A film characterized by being.
[2] The film according to [1], comprising a polymer including a structure represented by the following general formula (1), (2) or (3).

[In general formulas (1) and (2), ring α and ring β each independently represent a monocyclic or polycyclic ring, and are linked by one quaternary carbon. In the general formula (1), the linking group is bonded to any two carbons of the ring α. In the general formula (2), the linking group is bonded to any one carbon of the ring α and any one carbon of the ring β. In general formula (3), two rings γ and δ each independently represent a monocyclic or polycyclic ring, and are connected to one quaternary carbon on ring δ. The linking group is bonded to any carbon of ring γ. ]

[3] The film according to [1] or [2], wherein the average refractive index Nxy in the film plane is 0.02 or more larger than the refractive index Nz in the thickness direction.
[4] The method for producing a film according to any one of [1] to [3], comprising a step of stretching a film made of a resin having a glass transition temperature (Tg) of 250 ° C. or higher.
[5] The method according to [4], wherein the film is stretched by a press stretching method.
[6] The method according to [4], wherein the film is stretched by a biaxial stretching method.
[7] The method according to any one of [4] to [6], wherein the film is stretched in a state where the film contains a solvent.
[8] A film produced by the production method according to any one of [4] to [7].
[9] A film with a gas barrier layer having a gas barrier layer on the film according to any one of [1] to [3] and [8].
[10] A film with a transparent conductive layer having a transparent conductive layer on the film according to any one of [1] to [3], [8] and [9].
[11] A film with TFT having TFTs on the film according to any one of [1] to [3] and [8] to [10].
[12] An image display device using the film according to any one of [1] to [3] and [8] to [11] as a substrate.
[13] The image display device according to [12], wherein the image display device is a liquid crystal display device or an organic electroluminescence display device.

  The film of the present invention is characterized by high heat resistance, excellent optical properties and mechanical properties, and low linear thermal expansion coefficient. The image display device of the present invention is excellent in display quality. In particular, it is useful as a liquid crystal display device or an organic EL display device.

  Hereinafter, the film and the image display device of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  For the film of the present invention, a resin having a glass transition temperature (Tg) of 250 ° C. or higher is used. As long as the glass transition temperature (Tg) is a resin having a temperature of 250 ° C. or higher, details thereof are not limited. Examples thereof include polyester, polyarylate, polyamide, polyimide, polybenzoxazole, polyether, polysulfone, polyesteramide, polyesterimide, polyamideimide, polyethersulfone, and polyetherketone.

  Specific examples of the resin that can be used in the present invention are listed below, but the resin that can be used in the present invention is not limited to these.

The resin that can be used in the present invention is preferably a resin containing a structure represented by the general formulas (1) to (3) in the main chain.
In general formulas (1) and (2), ring α and ring β each independently represent a monocyclic or polycyclic ring, and are connected by one quaternary carbon. In the general formula (1), the linking group is bonded to any two carbons of the ring α. In the general formula (2), the linking group is bonded to any one carbon of the ring α and any one carbon of the ring β. In general formula (3), two rings γ and δ each independently represent a monocyclic or polycyclic ring, and are connected to one quaternary carbon on ring δ. The linking group is bonded to any carbon of ring γ.

  In the general formulas (1) and (2), the rings α and β each represent a polycyclic structure, but each independently preferably has 2 to 5 rings, and more preferably 2 to 3 rings. Rings α and β may have the same structure or different structures. Each ring constituting the polycycle may be an alicyclic ring, an aromatic ring, or a heterocyclic ring. The ring structure to which the linking group is bonded may be an alicyclic ring, an aromatic ring or a heterocyclic ring, but is preferably an aromatic ring.

  Rings α and β may have a substituent, and preferred substituents include an alkyl group (preferably having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group), Halogen atom (for example, chlorine atom, bromine atom, iodine atom, etc.), aryl group (preferably having 6-20 carbon atoms, for example, phenyl group, biphenyl group, naphthyl group, etc.), alkoxy group (preferably having 1-10 carbon atoms) , For example, methoxy group, ethoxy group, isopropoxy group, etc.), acyl group (C2-C10 is preferable, for example, acetyl group, propionyl group, butyryl group, etc.), acylamino group (C1-C10 is preferable, For example, a formylamino group, an acetylamino group, etc.), a nitro group, a cyano group, etc. are mentioned. More preferred are an alkyl group, a halogen atom, an aryl group, an alkoxy group, and a nitro group, and particularly preferred are an alkyl group and a halogen atom.

  In the above general formula (3), the ring δ represents a monocyclic or polycyclic structure, but is preferably monocyclic to pentacyclic, more preferably monocyclic to tetracyclic, and more preferably 2 to 4 More preferably, it is a ring. When the ring δ is polycyclic, at least one ring is preferably an aromatic ring. Ring γ represents a monocyclic or polycyclic structure, and is preferably a monocyclic structure. The ring γ and the ring δ may have a substituent as shown in the general formulas (1) and (2).

A preferred example of the general formula (3) is a resin containing a structure represented by the following general formula (4) in the main chain.

In the general formula (4), R ^{41 to} R ⁴⁴ each independently represents a substituent, and examples thereof include substituents as shown in the general formulas (1) and (2). It is more preferable that a and b represent the integer of 0-4 each independently, 0-3 are preferable and 0-2 are more preferable. c and d each independently represent an integer of 0 to 3, preferably 0 to 3, and more preferably 0 to 2. The position to which the linking group is bonded may be any position on the aromatic ring, but the quaternary carbon meta position or para position is preferred, and the para position is particularly preferred.

  The polymer used in the present invention may contain a plurality of repeating units represented by the general formulas (1) to (4), and the general formulas (1) to (4) as long as the effects of the present invention are not impaired. It may contain repeating units other than). The amount of the repeating units of the general formulas (1) to (4) in the polymer used in the present invention is usually 10 mol% or more, preferably 20 mol% or more, more preferably 30 mol% or more. .

  The linking group of the polymer containing the general formulas (1) to (4) as a repeating unit is a simple bond, ester bond, carbonate bond, amide bond, imide bond, ketone bond, ether bond, sulfone bond, urethane bond, urea bond. And benzoazole bond, and the like, preferably an ester bond, a carbonate bond, an amide bond, an imide bond, and an ether bond, and particularly preferably an ester bond, an amide bond, and an imide bond. It may be a polymer linked by one type of bond among various bonding modes, or may be a polymer linked by a plurality of combinations.

  Although the polymer containing the structure represented by general formula (1)-(4) below is mentioned, the polymer which can be used by this invention is not limited to these.

As a method for producing the film of the present invention, a known method can be adopted, but it is preferable to use a solution casting method or an extrusion molding method (melt molding method).
Regarding the casting and drying methods in the solution casting method, US Pat. No. 2,336,310, US Pat. No. 2,367,603, US Pat. No. 2,429,078, US Pat. No. 2,429,297, US Pat. No. 2,429,978, US Pat. No. 2,607,704, US Patent Nos. 2739069, U.S. Pat. No. 2,739,070, British Patent No. 640731, British Patent No. 736892, JP-B-45-4554, JP-B-49-5614, JP-A-60-17683, There are descriptions in Japanese Laid-Open Patent Publication Nos. 60-203430 and 62-115535.

  Examples of the production apparatus for producing the film of the present invention using the solution casting method include the production apparatus described in paragraphs [0061] to [0068] of JP-A-2002-189126, FIGS. Although mentioned, the manufacturing apparatus which can be used by this invention is not limited to these.

  In the solution casting method, the resin composition is dissolved in a solvent. The solvent to be used is not particularly limited as long as it can dissolve the resin composition, but it is particularly preferable to use a solvent that can dissolve a solid content concentration of 10% by mass or more at 25 ° C. The solvent used preferably has a boiling point of 250 ° C. or lower, and more preferably 205 ° C. or lower. A boiling point of 205 ° C. or lower is preferable because the solvent can be sufficiently dried and the solvent does not remain in the film.

  Examples of such solvents include methylene chloride, chloroform, tetrahydrofuran, benzene, cyclohexane, toluene, xylene, 1,2-dichloroethane, ethyl acetate, methyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, chlorobenzene, dimethylformamide, and dimethyl. Examples include acetamide, N-methylpyrrolidone, methanol, ethanol, cyclohexanone, and anisole, but the solvent that can be used in the present invention is not limited thereto.

  Two or more of the above solvents may be mixed and used. As an example of the mixed solvent, a solvent obtained by mixing one or several kinds of alcohol having 1 to 5 carbon atoms with methylene chloride can be given. In this case, the alcohol content is preferably 5 to 20% by mass with respect to the entire solvent. Furthermore, a solvent in which an ether, ketone and ester having 3 to 12 carbon atoms are appropriately mixed may be mentioned as a preferred example. In this case, one to several alcohols having 1 to 5 carbon atoms may be mixed. In addition, examples of the organic solvent described in JIII Journal of Technical Disclosure No. 2001-1745 and paragraph 6 are also preferable examples.

  The concentration of the resin composition in the solution used for solution casting is suitably 5 to 60% by mass, preferably 10 to 40% by mass, and more preferably 10 to 30% by mass. . If the density | concentration of a resin composition is 5-60 mass%, moderate viscosity will be obtained, thickness adjustment will be easy, and favorable film forming property will be obtained.

  The method for casting the solution is not particularly limited, and for example, it can be cast on a flat plate or a roll using a bar coater, a T die, a T die with a bar, a doctor blade, a roll coat, a die coat or the like.

The temperature at which the solvent is dried varies depending on the boiling point of the solvent used, but it is preferable to dry the solvent in two stages. As a first step, drying is performed until the solvent concentration is 50% by mass or less, preferably 40% by mass or less at 10 to 100 ° C., and then, as a second step, the film is peeled off from a flat plate or a roll. It is preferable to dry in the temperature range of Tg.
In addition, when peeling a film from a flat plate or a roll, even if it peels immediately after completion | finish of drying of a 1st step, you may peel after cooling once.

  The film of the present invention is preferably stretched. As the stretching method, known methods can be used. For example, JP-A-62-115035, JP-A-4-152125, JP-A-4-284221, JP-A-4-298310, JP-A-11-48271. The film can be stretched by a roll uniaxial stretching method, a tenter uniaxial stretching method, a simultaneous biaxial stretching method, a sequential biaxial stretching method, an inflation method, or a rolling method, which is described in a publication. Hereinafter, the stretching method using a tenter will be described in detail as an example.

  The film is stretched at room temperature or under heating conditions. The film can be stretched while performing a drying treatment, and it is particularly effective to stretch in a state where the solvent remains. The stretching of the film may be uniaxial stretching or biaxial stretching, but biaxial stretching is preferred. For example, the film is stretched by adjusting the speed of the film transport roller so that the film winding speed is higher than the film peeling speed. The film can also be stretched by conveying while holding the width of the film with a tenter and gradually widening the width of the tenter. After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine). The stretching ratio of the film (the ratio of the increase due to stretching relative to the original length) is preferably 0.5 to 300%, more preferably 1 to 200%, particularly 1 to 100%. Preferably there is.

  The stretching speed is preferably 5% / min to 1000% / min, and more preferably 10% / min to 500% / min. The stretching temperature is preferably from Tg to (Tg + 50 ° C.), more preferably from Tg to (Tg + 40 ° C.), particularly from Tg to (Tg + 30 ° C.), based on the glass transition temperature (Tg) of the resin used. Preferably it is done. The stretching is preferably performed by a heat roll, a radiant heat source (such as an IR heater) and / or hot air. Moreover, you may provide a thermostat in order to improve the uniformity of temperature.

  It is preferable to provide a preheating step before stretching. Moreover, you may heat-process after extending | stretching. The heat treatment is preferably performed at a temperature 20 ° C. to 10 ° C. higher than the glass transition temperature of the film, and the heat treatment time is preferably 1 second to 3 hours. The heating method may be zone heating or partial heating using an infrared heater. You may slit the both ends of a film in the middle or the end of a process. These slit scraps are preferably recovered and reused as raw materials. Further, regarding the tenter, as described in JP-A-11-0777718, when the web is dried while the width is maintained by the tenter, the drying gas blowing method, the blowing angle, the wind speed distribution, the wind speed, the air volume, and the temperature difference. By properly controlling the difference in air volume, the upper and lower blowing air volume ratio, the use of high specific heat drying gas, etc., quality deterioration such as flatness when increasing the speed by the solution casting method or widening the web width is prevented. can do.

  Further, as described in JP-A-11-077782, in order to prevent the occurrence of unevenness, the stretched thermoplastic resin film is subjected to heat treatment by providing a temperature gradient in the width direction of the film in the thermal relaxation process after the stretching process. You can also.

  Furthermore, in order to prevent the occurrence of unevenness, as described in JP-A-4-204503, the film can be stretched with the solvent content of 2 to 10% based on the solid content.

  Further, in order to suppress curling due to the regulation of the clip biting width, as described in Japanese Patent Laid-Open No. 2002-248680, the tenter clip biting width D is set to D ≦ (33 / (log stretching ratio × log volatilization). Minutes)) and stretching, curling can be suppressed and film transport after the stretching process can be facilitated.

  Furthermore, in order to achieve both high-speed soft film conveyance and stretching, tenter conveyance can be switched between the first half pin and the second half clip as described in JP-A-2002-337224.

  Further, in order to produce an optical film having a small Re and no variation, as described in JP-A-2002-31245, the peeled web is fed to the first tenter device and both sides of the web in the width direction are fed. Grasping the edge to keep the web width constant or stretching the web in the width direction, drying the web to obtain a film, and secondly sending the film to a device to the tenter to the width direction of the film A step of holding both edges and keeping the width of the film constant or stretching the film in the width direction can also be performed.

  Further, as described in Japanese Patent Application Laid-Open No. 2003-014933, as a method of stretching, a tenter that stretches in the lateral direction by fixing both ends of the web with clips and pins and widening the interval between the clips and pins in the lateral direction. A method using (lateral stretching machine) can also be adopted. Further, in order to stretch or shrink in the longitudinal direction, it is possible to widen or shrink the interval in the transport direction of the clip or pin in the transport direction (vertical direction) using a simultaneous biaxial stretching machine. In addition, driving the clip portion by the linear drive method is preferable because it can be smoothly stretched and the risk of breakage can be reduced, and as a method of stretching in the longitudinal direction, a difference in peripheral speed is applied to a plurality of rolls. It is also possible to use a method of stretching in the longitudinal direction by utilizing the difference in the peripheral speed of the rolls. These stretching methods may be used in combination, and the stretching process may be performed in two or more stages, such as longitudinal stretching, lateral stretching, longitudinal stretching or longitudinal stretching, longitudinal stretching.

  Furthermore, in order to prevent foaming of the tenter-dried web, improve detachability, and prevent dust generation, as described in Japanese Patent Application Laid-Open No. 2003-004374, the hot air of the dryer is heated at both edges of the web. It is also possible to use a drying device in which the width of the dryer is shorter than the width of the web so as not to hit.

  Further, in order to prevent foaming of the tenter-dried web, improve detachability, and prevent dust generation, as described in JP-A-2003-019757, dry air hits the holding portion of the tenter. It is also possible to employ a technique of providing a wind shielding plate inside the both side ends of the web so as not to be present.

  Furthermore, in order to stably carry and dry, as described in JP-A-2003-053749, the thickness after drying of both ends of the film carried by the pin tenter is X μm, and the product part of the film When the average thickness after drying is T μm, the relationship between X and T is (1) T ≦ 60, 40 ≦ X ≦ 200, (2) 60 <T ≦ 120, 40+ (T− When 60) × 0.2 ≦ X ≦ 300 or (3) 120 <T, the relationship of 52+ (T−120) × 0.2 ≦ X ≦ 400 may be satisfied.

  Further, in order to prevent wrinkles in the multistage tenter, as described in JP-A-2-182654, in the tenter device, a heating chamber and a cooling chamber are provided in the dryer of the multistage tenter, It is also possible to cool the clip-chain separately.

  Further, in order to prevent web breakage, wrinkles, and conveyance failure, as described in Japanese Patent Laid-Open No. 9-073315, the pin density of the pin tenter is increased and the outer pin density is decreased. You can also

  Further, in order to prevent foaming of the web itself and adhesion of the web to the holding means in the tenter, as described in JP-A-9-085846, in the tenter drying apparatus, both side edge portions of the web are held. The pin can be cooled to below the foaming temperature of the web with a blow-out type cooler, and the pin immediately before the web can be entrapped can be cooled to the gelation temperature of the dope in the duct type cooler + 15 ° C. or lower.

  Furthermore, in order to prevent pin tenter losing and improve foreign matter, as described in JP-A-2003-103542, in the pin tenter, the insertion structure is cooled and brought into contact with the insertion structure. It is also possible to employ a solution casting method in which the surface temperature of the web does not exceed the gelling temperature of the web.

  Further, as described in JP-A-11-0777718, in order to prevent quality deterioration such as flatness when the speed is increased by the solution casting method or the width of the web is widened by a tenter. When drying the web in the tenter, the wind speed is 0.5 to 20 (40) m / s, the transverse temperature distribution is 10% or less, the web up-and-down air volume ratio is 0.2 to 1, the dry gas ratio Can also be 30-250 J / Kmol. Japanese Patent Application Laid-Open No. 11-077718 describes preferable drying conditions according to the amount of residual solvent in drying in a tenter. Specifically, (1) after the web is peeled from the support, the angle at which the blowout port blows out is 30 ° to 150 ° with respect to the film plane until the residual solvent amount in the web reaches 4% by weight. When the wind speed distribution on the surface of the film located in the range of ° and the dry gas blowing direction is based on the upper limit value of the wind speed, the difference between the upper limit value and the lower limit value should be within 20% of the upper limit value. Blowing dry gas to dry the web. (2) When the amount of residual solvent in the web is 70 to 130% by weight, the wind speed on the web surface of the dry gas blown from the blow type dryer is set to 0. 5 m / sec to 20 m / sec, (3) When the residual solvent amount is 4% by weight or more and less than 70% by weight, the dry gas wind blown out at a wind speed of 0.5 m / sec to 40 m / sec. Dried by When the temperature distribution of the dry gas in the width direction of the web is based on the upper limit value of the gas temperature, the difference between the upper limit value and the lower limit value should be within 10% of the upper limit value. (4) Residual solvent in the web When the amount is 4% by weight to 200% by weight, the air flow ratio q of the dry gas blown out from the blow-out port of the blow-type dryer located above and below the conveyed web can be set to 0.2 ≦ q ≦ 1. Furthermore, as a preferred embodiment, (5) at least one gas is used as the drying gas, and the average specific heat of the gas is 31.0 J / K · mol to 250 J / K · mol, (6) It is also possible to dry with a drying gas having a saturated vapor pressure in which the concentration of the organic compound that is liquid at room temperature contained in the drying gas during drying is 50% or less.

  In order to improve flatness, improve quality deterioration due to tearing in the tenter, and increase productivity, as described in JP-A-11-090943, an arbitrary transport length of the tenter is used. The ratio Lr = Ltt / Lt between the length Lt (m) and the total length Ltt (m) in the conveying direction of the portion where the clip of the tenter having the same length as Lt holds the web is 1.0 ≦ It can also be set as Lr <= 1.99. At this time, it is preferable that the part holding the web is arranged without a gap when viewed from the web width direction.

  Further, when introducing a web into a tenter, as described in JP-A-11-090944, an apparatus for producing a plastic film is used in order to improve flatness deterioration and introduction instability caused by sagging of the web. , A sag suppressing device in the width direction of the web can be installed before the tenter entrance. At this time, it is preferable that the sagging suppression device is a rotating roller that rotates in a direction range of 2 to 60 ° in the width direction. It is also preferable to install an air intake device on the top of the web or install a blower that can blow air from under the web.

  In order to produce a film having stable physical properties, as described in JP-A-2000-289903, a web having a solvent content of 50 to 12% by mass after peeling is applied with a tension in the width direction of the web. It is also possible to perform processing using a transport device that transports while giving. That is, the web width is detected by the web width detection means, the web holding means, and the conveying device having two or more variable bending points, the web width is calculated from the detection signal, and the position of the bending point is detected. Can be changed.

  Furthermore, in order to improve the clipping property, prevent web breakage for a long period of time, and obtain a film with excellent quality, as described in Japanese Patent Application Laid-Open No. 2003-033933, both the left and right sides of the portion near the entrance of the tenter A web-side edge curl-preventing guide plate is disposed at least below the upper and lower sides of the left and right side edges of the web, and the web contact surface of the guide plate is arranged in the web conveyance direction. The apparatus comprised by the resin part for webs and the metal part for web contact can also be used. A preferable aspect at this time is (1) an aspect in which the web contact resin portion on the web facing surface of the guide plate is disposed on the upstream side in the web conveyance direction, and the web contact metal portion is disposed on the downstream side, and (2) the guide. A mode in which a step (including an inclination) between the web contact resin portion and the web contact metal portion of the plate is within 500 μm, (3) contact with the web of the web contact resin portion and the web contact metal portion of the guide plate An aspect in which the distance in the width direction is 2 to 150 mm, and (4) an aspect in which the distance in the web conveyance direction in contact with the web of the web contact resin portion and the web contact metal portion of the guide plate is 5 to 120 mm, respectively. (5) A mode in which the web contact resin portion of the guide plate is provided on the metal guide substrate by surface resin processing or resin coating, (6) the web contact resin portion of the guide plate is resin. (7) A mode in which the distance between the web-facing surfaces of the guide plates disposed above and below the left and right side edge portions of the web is 3 to 30 mm, and (8) the left and right sides of the web A mode in which the distance between the web facing surfaces of the upper and lower guide plates at both side edges is enlarged at a rate of 2 mm or more per 100 mm width in the width direction of the web and inward, (9) Both the upper and lower guide plates have a length of 10 to 300 mm at the left and right side edges, and the upper and lower guide plates are arranged so as to be displaced back and forth along the web conveying direction. A mode in which the distance between the shifts is −200 to +200 mm, (10) a mode in which the web facing surface of the upper guide plate is made of only resin or metal, (11) An embodiment in which the web contact resin portion of the guide plate is made of Teflon (registered trademark) and the web contact metal portion is made of stainless steel. (12) The web facing surface of the guide plate or the web contact resin provided thereon And / or the surface roughness of the metal part for web contact is 3 μm or less. Moreover, the installation position of the web side edge curl prevention upper and lower guide plates is preferably from the peeling side end of the support to the tenter introduction part, and more preferably installed near the tenter inlet.

  Furthermore, in order to prevent the cutting and unevenness of the web that occurs during drying in the tenter, as described in JP-A-11-048271, when the solvent content of the web is 50 to 12% by mass Then, the film can be stretched and dried by a width stretching apparatus, and a pressure of 0.2 to 10 KPa can be applied from both sides of the web by a pressing apparatus when the solvent content of the web is 10% by mass or less. At this time, it is preferable to finish applying the tension when the solvent content is 4% by weight or more. Moreover, when applying a pressure from both sides of a web (film) using a nip roll, about 1-8 sets of a pair of nip rolls are preferable, and the temperature in the case of pressurizing has preferable 100-200 degreeC.

  In order to obtain a film having a thin film thickness and excellent optical isotropy and flatness, as described in JP 2000-239403 A, when introduced into a tenter with a residual solvent ratio X at the time of peeling. It is also possible to perform film formation with the relationship of the residual solvent ratio Y in the range of 0.3X ≦ Y ≦ 0.9X.

  As described in JP-A-2002-286933, examples of a method for stretching a film to be formed by casting include a method of stretching under heating conditions and a method of stretching under solvent-containing conditions. When stretching under heating conditions, it is preferable to stretch at a temperature below the glass transition point of the resin. On the other hand, when stretching a cast film under solvent-impregnated conditions, it is once dried. It is possible to stretch the film by bringing the film into contact with the solvent again to impregnate the solvent.

  In the present invention, a press stretching method can be mentioned as a preferred method. In this specification, the “press stretching method” refers to a stretching method in which a film is stretched isotropically by applying pressure from above and below.

  Examples of the press stretching method include Japanese Patent Publication No. 63-24806, Japanese Patent Publication No. 1-35204, Japanese Patent Publication No. 1-32055, Japanese Patent Publication No. 3-67845, Japanese Patent Publication No. 4-74167, and the 9th volume of molding process. No. 4, pages 306-312, molding process No. 9, No. 5, page 356-362, molding process No. 9, No. 9, pages 713-718. In particular, the air gap described in Molding Volume 9 No.4 pages 306-312, Molding Volume 9 No.5 pages 356-362, Molding Volume 9 No.9 pages 713-718 The method, the 2-station method, the mold temperature constant method and the like can be preferably used. The pressure at the time of pressing is preferably 10 MPa to 500 MPa, more preferably 20 MPa to 500 MPa, and particularly preferably 35 MPa to 500 MPa. The mold temperature during pressing is preferably Tg to Tg + 100 ° C, more preferably Tg to (Tg + 75) ° C, and particularly preferably Tg to (Tg + 50) ° C. The stretching ratio by press stretching is preferably 1.2 to 10 times, more preferably 1.5 to 10 times, and particularly preferably 2.0 times to 10 times. 10-500 micrometers is preferable, as for the thickness of the film after extending | stretching, 20-500 micrometers is more preferable, and 25-500 micrometers is especially preferable. The draw ratio here is an area ratio based on the area before stretching.

  At the time of press stretching, a lubricating film or a lubricant may be used. Examples of the lubricating resin film include polytetrafluoroethylene, polypropylene, and polyethylene. Examples of the lubricant include polydimethylsiloxane. Moreover, you may mix a solvent and a plasticizer with resin for the purpose of reducing Tg at the time of press extending | stretching. Furthermore, only one preform may be used at the time of press stretching, and a plurality of preforms may be laminated. When laminating a plurality of sheets, it is preferable to use a lubricating film and / or a lubricant between the preforms. The preform referred to here is a plate-like resin before stretching. The preform used in the present invention may be prepared by melt molding or may be prepared by solution molding. The preform as used in the present invention refers to a film and / or sheet before press-stretching.

  When the film of the present invention is stretched, it can be stretched in a state containing a solvent for the purpose of lowering the apparent Tg. In the case of a film having a high Tg, the film is thermally decomposed by thermal stretching. However, the film can be stretched at a temperature lower than the thermal decomposition temperature by containing a solvent.

  1-50 mass% is preferable, as for the solvent content of the film at the time of extending | stretching, 1-45 mass% is more preferable, and 1-40 mass% is especially preferable. The solvent content may change during stretching. 0-250 degreeC is preferable, as for the temperature at the time of extending | stretching in the state containing the solvent, 0-230 degreeC is more preferable, and 10-220 degreeC is especially preferable. As a method of containing the solvent, there are a method of using the state of the drying process of the film and a method of containing the solvent after the film is dried, and the former is particularly preferable. Any solvent may be used, but the same type as that used for the dope is preferable.

  As a stretching method in the case of stretching in a state containing a solvent, a known stretching method can be used. For example, JP-A-62-115035, JP-A-4-152125, JP-A-4-284111, It can be stretched by a roll uniaxial stretching method, a tenter uniaxial stretching method, a simultaneous biaxial stretching method, a sequential biaxial stretching method, an inflation method, or a rolling method as described in JP-A-4-298310 and JP-A-11-48271. . Moreover, the press drawing method mentioned above can be used.

  Among the conditions for stretching in a state in which a solvent is contained, conditions other than the stretching temperature can be the conditions for stretching in a state not containing the solvent described above.

  When biaxial stretching is performed in a state of containing a solvent, the stretching ratio is preferably 1.2 to 10 times in terms of area ratio, more preferably 1.5 times to 10 times, and particularly preferably 2.1 times to 10 times.

  The film of the present invention may be heat-treated for the purpose of removing residual stress after stretching. The heat treatment temperature is preferably 250 ° C to (Tg + 20 ° C), more preferably 260 ° C to (Tg + 20 ° C), and particularly preferably 270 ° C to (Tg + 20 ° C).

  In the film of the present invention, the relationship between the average refractive index Nxy in the film plane and the refractive index Nz in the thickness direction is preferably Nxy−Nz ≧ 0.02, and Nxy−Nz ≧ 0.025. More preferably, Nxy−Nz ≧ 0.03 is particularly preferable. In the film of the present invention, the difference between the refractive indices Nx and Ny in the film plane is preferably 0.02 or less, more preferably 0.018 or less, and particularly preferably 0.015 or less. preferable. Here, Nx means the refractive index in the direction where the value of the refractive index in the film plane is maximum, and Ny means the refractive index in the film plane in the direction perpendicular to the Nx direction. Nxy is calculated by (Nx + Ny) / 2.

  The weight average molecular weight of the resin used in the present invention is preferably 10,000 to 5,000,000, more preferably 15,000 to 5,000,000, and particularly preferably 20,000 to 5,000,000.

  The glass transition temperature (Tg) of the resin used in the present invention is preferably 250 to 450 ° C, more preferably 250 to 400 ° C, and further preferably 250 to 380 ° C.

  The resin used in the present invention may be used by mixing inorganic substances. 1-30 mass% is preferable, as for the quantity of the inorganic substance to mix, 1-25 mass% is more preferable, and 1-20 mass% is especially preferable. As the inorganic substance to be mixed, a metal oxide and / or a metal complex oxide, a metal oxide obtained by a sol-gel reaction, an inorganic layered compound, or an organic inorganic layered compound can be used.

  The linear thermal expansion coefficient of the film of the present invention is −20 to 40 ppm / ° C., preferably −15 to 25 ppm / ° C., and −10 to 15 ppm / ° C. in the temperature range of 25 ° C. to 250 ° C. Is more preferable. The film of the present invention having a linear thermal expansion coefficient of −20 to 40 ppm / ° C. in a temperature range of 25 ° C. to 250 ° C. is an inorganic material due to a difference in expansion coefficient due to heating when an inorganic material such as a gas barrier layer or a transparent electrode is laminated. There are advantages such as the ability to suppress cracking of the layer and the suppression of misalignment between the inorganic layers.

  The film of the present invention preferably has a light transmittance of 420 nm at a film thickness of 50 μm of 70% to 100%, more preferably 75% to 100%, and particularly preferably 80% to 100%. The total light transmittance at a wavelength of 400 to 700 nm is preferably 70 to 100%, more preferably 80 to 100%, and particularly preferably 85 to 100%.

  The haze of the film of the present invention is preferably 3% or less, more preferably 2% or less, and even more preferably 1% or less.

  Other layers may be formed on the film surface of the present invention depending on the application, and saponification, corona treatment, flame treatment, glowing may be performed on the film surface for the purpose of improving adhesion to other parts. A process such as a discharge process may be performed. Further, an anchor layer may be provided on the film surface.

  A transparent conductive layer may be laminated on at least one side of the film of the present invention. A known metal film, metal oxide film, or the like can be applied as the transparent conductive layer. Among these, a metal oxide film having excellent transparency, conductivity, and mechanical properties is preferably used as the transparent conductive layer. The metal oxide film is, for example, a metal oxide film of indium oxide, cadmium oxide or tin oxide to which tin, tellurium, cadmium, molybdenum, tungsten, fluorine, zinc, germanium or the like is added as an impurity; Examples thereof include metal oxide films such as zinc and titanium oxide. Among them, an indium oxide thin film mainly composed of tin oxide and containing 2 to 15% by mass of zinc oxide is excellent in transparency and conductivity, and is preferably used.

  The transparent conductive layer can be formed by any method as long as it can form a target thin film. For example, a vapor deposition method that forms a film by depositing a material from the vapor phase, such as sputtering, vacuum deposition, ion plating, plasma CVD, and Cat-CVD, is suitable. The film can be formed by the methods described in JP-A Nos. 2002-322561 and 2002-361774. Among these, the sputtering method is preferable from the viewpoint that particularly excellent conductivity and transparency can be obtained.

  The preferred degree of vacuum of the sputtering method, vacuum deposition method, ion plating method, or plasma CVD method is 0.133 mPa to 6.65 Pa, preferably 0.665 mPa to 1.33 Pa. Before forming the transparent conductive layer, it is preferable to subject the base film to a surface treatment such as plasma treatment (reverse sputtering) or corona treatment. Moreover, you may heat up to 50-200 degreeC during providing the transparent conductive layer.

  The film thickness of the transparent conductive layer thus obtained is preferably 20 to 500 nm, and more preferably 50 to 300 nm.

  The surface electrical resistance of the transparent conductive layer measured at 25 ° C. and 60% relative humidity is preferably 0.1 to 200Ω / □, and more preferably 0.1 to 100Ω / □. More preferably, it is 0.5-60Ω / □. The light transmittance at 420 nm of the transparent conductive layer is preferably 80% or more, more preferably 83% or more, and further preferably 85% or more.

  In the film of the present invention, a gas barrier layer can be laminated on at least one surface in order to suppress gas permeability. As a preferable gas barrier layer, for example, a metal oxide mainly composed of one or more metals selected from the group consisting of silicon, aluminum, magnesium, zinc, zirconium, titanium, yttrium and tantalum, silicon, aluminum, Mention may be made of films formed of metal nitrides of boron or mixtures thereof. Among these, the main component is silicon oxide having a ratio of the number of oxygen atoms to the number of silicon atoms of 1.5 to 2.0 in terms of gas barrier properties, transparency, surface smoothness, flexibility, film stress, cost, and the like. A film formed of a metal oxide is good. The gas barrier layer made of these inorganic compounds is formed by vapor deposition such as sputtering, vacuum deposition, ion plating, plasma CVD, Cat-CVD, etc., by depositing a material from the vapor phase to form a film. Can be made. Among these, the sputtering method and the Cat-CVD method that can provide particularly excellent gas barrier properties are preferable. Further, the temperature may be raised to 50 to 250 ° C. while the gas barrier layer is provided.

  The thickness of the gas barrier layer is preferably 10 to 300 nm, and more preferably 30 to 200 nm.

  The gas barrier layer may be provided on the same side as the transparent conductive layer or on the opposite side.

The gas barrier performance of the film of the present invention is preferably 40 ° C., water vapor permeability measured at 90% relative humidity is 0~5g / m ² · day, and more to be 0~3g / m ² · day Preferably, it is 0-2 g / m ² · day. Further, 40 ° C., the oxygen permeability measured at 90% relative humidity is preferably ^{0~1ml / m 2 · day · atm} , more to be 0~0.7ml / m ² · day · atm Preferably, 0-0.
More preferably, it is 5 ml / m ² · day · atm. When the gas barrier performance is within the above range, for example, when used in an organic EL display device or a liquid crystal display device, it is preferable that deterioration of the EL element due to water vapor and oxygen can be substantially eliminated.

  In order to improve the gas barrier performance, it is preferable to form a defect compensation layer adjacent to the gas barrier layer. As the defect compensation layer, for example, (1) an inorganic oxide layer produced by using a sol-gel method as described in US Pat. No. 6,171,663 and Japanese Patent Application Laid-Open No. 2003-94572, (2) US Pat. The organic layer described in the specification, No. 64163645 can be used. These defect compensation layers can be prepared by vapor deposition under vacuum and then curing with ultraviolet rays or electron beams, or by applying and then curing with heating, electron beams, ultraviolet rays or the like. When the defect compensation layer is produced by a coating method, various conventional coating methods such as spray coating, spin coating, and bar coating can be used.

  The film of the present invention may be provided with an inorganic barrier layer, an organic barrier layer, an organic-inorganic hybrid barrier layer, etc. for the purpose of imparting chemical resistance.

[Image display element]
The film of the present invention described above can be used for an image display device. Here, the type of the image display device is not particularly limited, and conventionally known ones can be exemplified. Moreover, the flat panel display excellent in display quality can be produced using the film of this invention as a board | substrate. Flat panel displays include liquid crystals, plasma displays, organic electroluminescence (EL), inorganic electroluminescence, fluorescent display tubes, light emitting diodes, field emission types, etc. In addition to these, display methods in which glass substrates have conventionally been used It can be used as a substrate in place of the glass substrate. Furthermore, the film of the present invention can be applied to uses such as solar cells and touch panels in addition to flat panel displays. The touch panel can be applied to, for example, those described in JP-A-5-127822, JP-A-2002-48913, and the like.

  The film of the present invention can be preferably used as a substrate for a thin film transistor (TFT) display element. As a method for manufacturing the TFT array, for example, a method described in JP-T-10-512104 can be used. Further, these substrates may have a color filter for color display. The color filter may be manufactured using any method, but is preferably manufactured using a photolithography technique.

  When the film of the present invention is used as a substrate for a liquid crystal display device or the like, the resin composition constituting the film is preferably an amorphous polymer in order to achieve optical uniformity. Furthermore, for the purpose of controlling retardation (Re) and its wavelength dispersion, resins having different signs of intrinsic birefringence can be combined, or resins having large (or small) wavelength dispersion can be combined.

The film of the present invention is preferably laminated by combining different resin compositions from the viewpoint of controlling retardation (Re) and improving gas permeability and mechanical properties. A preferred combination of different resin compositions is not particularly limited, and any of the above-described resin compositions can be used.

  A reflective liquid crystal display device generally has a configuration of a lower substrate, a reflective electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, a transparent electrode, an upper substrate, a λ / 4 plate, and a polarizing film in order from the bottom. . Among these, the film of the present invention can be used as a transparent electrode and / or an upper substrate. In the case of color display, it is preferable to further form a color filter layer between the reflective electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.

  The transmissive liquid crystal display device includes, in order from the bottom, a backlight, a polarizing plate, a λ / 4 plate, a lower transparent electrode, a lower alignment film, a liquid crystal layer, an upper alignment film, an upper transparent electrode, an upper substrate, a λ / 4 plate, and It generally has a configuration of a polarizing film. Among these, the film of the present invention can be used as an upper transparent electrode and / or an upper substrate. In the case of color display, it is preferable to further provide a color filter layer between the lower transparent electrode and the lower alignment film, or between the upper alignment film and the transparent electrode.

  The type of the liquid crystal layer (liquid crystal cell) is not particularly limited, but TN (Twisted Nematic), IPS (In-P1ane Switching), FLC (Ferroelectric Liquid Crystal 1), AFLC (Anti-ferroelectric Liquid Crystal), OCB (Optica 1ly Compensated Bend) Various display modes such as STN (Super Twisted Nematic), VA (Vertically Aligned), and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The film of the present invention is also effective for use in a display mode liquid crystal display device. In addition, the present invention is effective when used for any of a transmissive, reflective, and transflective liquid crystal display device.

  Regarding the liquid crystal cell and the liquid crystal display device, JP-A-2-176625, JP-B-7-69536, MVA (SID97, Digest of tech. Papers (Preliminary Proceedings) 28 (1997) 845), SID99, Digest of tech Papers 30 (1999) 206), JP 11-258605 A, SURVAIVAL (Monthly Display, Vol. 6, No. 3 (1999) 14), PVA (Asia Display 98, Proc. Of the- 18th-Inter. Display res. Conf. (1998) 383), Para-A (LCD / PDP International 99), DDVA (SID98, Digest of tech. Papers 29 (1998) 838), EOC (SID98, Digest of tech. Papers (Preliminary Collection) 29 (1998) 319), PSHA (SID98, Digest of tech. Papers (Preliminary Collection) 29 (1998) 1081), RFFMH (Asia Display 98, Proc. Of the -18th-Inter. Display res. Conf. (Preliminary Collection) (1998) 375), HMD (SID98, Digest of tech. Papers (Preliminary Collection) 29 (1998) 702), JP-A-10-123478, International Publication No. 98/48320 Pamphlet Bets are described in Patent No. 3022477 discloses, and pamphlet of International Laid-Open No. 00/65384 and the like.

  The film of the present invention can also be used for organic EL display applications. The specific layer structure of the organic EL display device includes anode / light emitting layer / transparent cathode, anode / light emitting layer / electron transport layer / transparent cathode, anode / hole transport layer / light emitting layer / electron transport layer / transparent cathode, Anode / hole transport layer / light emitting layer / transparent cathode, anode / light emitting layer / electron transport layer / electron injection layer / transparent cathode, anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection Examples include layer / transparent cathode.

  In the organic EL display device in which the film of the present invention can be used, a direct current (which may include an alternating current component if necessary) voltage (usually 2 to 40 V) or a direct current is applied between the anode and the cathode. Thus, light emission can be obtained. Regarding driving of these light emitting elements, for example, JP-A-2-148687, JP-A-6-301355, JP-A-5-290080, JP-A-7-134558, JP-A-8-234665, and JP-A-8-240447. US Pat. Nos. 5,828,429 and 6023308, Japanese Patent No. 2784615, and the like can be used.

  As a full color display method of the organic EL display device, any method such as a color filter method, a three-color independent light emission method, a color conversion method, or the like may be used.

  Either a passive matrix or an active matrix may be used as a driving method for the liquid crystal display device and the organic EL display device.

  The film of the present invention is an optical film, retardation film, polarizing plate protective film, transparent conductive film, substrate for display device, substrate for flexible display, substrate for flat panel display, substrate for solar cell, substrate for touch panel, for flexible circuit It can be used for a substrate, an optical disk protective film and the like.

  The features of the present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Synthesis Example 1) Synthesis of Exemplified Compound P-30 In a 1 liter three-necked flask equipped with a stirrer and a reflux condenser, 4,67 '(9-fluorenylidene) dianiline, 15.67 g, 2,2'-bistrifluoro 4.80 g of methyl-4,4′-diaminobiphenyl, 6.49 g of 2,6-naphthalenedicarboxylic acid, 4.98 g of terephthalic acid, 37.23 g of triphenyl phosphite, 6.0 g of lithium chloride, 30 ml of dehydrated pyridine and dehydrated N -200 ml of methylpyrrolidone was added and stirred at 100 ° C for 3 hours under a nitrogen stream. The reaction solution was diluted with 300 ml of dimethylacetamide and then poured into 2 L of methanol to obtain a white powder. The obtained powder was collected by filtration, dispersed in 500 ml of methanol and washed by heating under reflux for 1 hour. The white powder was collected by filtration and dried to obtain 25.0 g of Exemplified Compound P-30. As a result of measurement by GPC (DMF solvent; polystyrene conversion (manufactured by Tosoh Corp., HLC-8120GPC)), the weight average molecular weight was 90,000. The glass transition temperature of the film having a thickness of 100 μm obtained by casting was measured using TMA8310 (manufactured by Rigaku Corporation, Thermo Plus series) and found to be 360 ° C.

(Synthesis Example 2) Synthesis of Exemplified Compound P-32 1) Synthesis of 2,2′-bistrifluoromethyl-4,4′-dihydroxybiphenyl In a 2 L three-necked flask equipped with a stirrer, a reflux condenser, and a dropping funnel, 20 g of 2'-bistrifluoromethyl-4,4'-diaminobiphenyl, 130 ml of 36.5% hydrochloric acid aqueous solution and 592 ml of distilled water were added and dissolved while heating and stirring. The solution was cooled to −5 ° C., and a solution obtained by dissolving 8.62 g of sodium nitrite in 55.1 ml of water was slowly added dropwise while maintaining the internal temperature at 0 to 5 ° C. After completion of dropping, the mixture was stirred for 20 minutes while maintaining the temperature (diazo solution A).
To a 5-liter three-necked flask equipped with a stirrer, a reflux condenser, and a dropping funnel, 110 ml of phosphoric acid and 1500 ml of distilled water were added, and the diazo solution A was slowly dropped while stirring at 100 ° C. After completion of the dropwise addition, the mixture was heated to reflux for 20 minutes, and then the reaction solution was cooled, and ethyl acetate was added to extract the organic layer. Further, magnesium sulfate was added to the organic layer, dried and concentrated, and then purified by silica gel column chromatography (developing solvent hexane / ethyl acetate = 3/1; Rf = 0.3) to obtain 2,2′-bistrifluoromethyl. 12 g of -4,4'-dihydroxybiphenyl was obtained. The product was identified by 400 MHz ¹ HNMR.
¹ HNMR (d ₆ -DMSO), δ (ppm): 7.10 (d, 2H), 7.19 (d, 2H), 7.20 (s, 2H), 10.30 (s, 2H)

2) Synthesis of Exemplified Compound P-32 In a 300 ml three-neck flask equipped with a stirrer, 2.66 g of 4,4 ′-(9-fluorenylidene) diphenol, 2,2′-bistrifluoromethyl-4,4′- 3.86 g of dihydroxybiphenyl, 60 mg of hydrosulfite sodium, 278 mg of tetra n-butylammonium chloride, 65 ml of methylene chloride, and 75 ml of distilled water were added and dissolved by stirring under a nitrogen stream. A solution prepared by dissolving 2.54 g of 2,6-naphthalenedicarboxylic acid chloride and 2.03 g of terephthalic acid chloride in 30 ml of methylene chloride was added to the solution. Further, a 2 mol / L sodium hydroxide aqueous solution (21 ml), 4-t-butylphenol (120.2 mg) and water (9 ml) were added dropwise at 20 to 23 ° C. over 1 hour. After stirring for 3 hours after completion of the dropwise addition, the reaction solution was transferred to a 1-liter three-necked flask, and 350 μl of acetic acid and 300 ml of ethyl acetate were slowly added. The obtained polymer powder was collected by filtration, washed successively with 300 ml of ethyl acetate, 300 ml of water, and 300 ml of methanol and dried to obtain 8.13 g of Exemplified Compound P-32. As a result of measurement by GPC (THF solvent; polystyrene conversion (manufactured by Tosoh Corporation, HLC-8120GPC)), the weight average molecular weight was 80,000. The glass transition temperature of a film having a thickness of 100 μm obtained by stretching was measured using a TMA8310 (manufactured by Rigaku Corporation, Thermo Plus series) and found to be 305 ° C.

  The method for producing a film by press stretching is described below. In all examples, the size of the preform was (100 mm × 100 mm × 0.5 mm), and the preform was preheated at a predetermined temperature and a pressure of 1 MPa for 30 minutes. Moreover, press drawing was performed by the air gap method. A Teflon film (Teflon: registered trademark) (75 μm) was used as the lubricating film.

Example 1
P-8 was synthesized by the method described in JP-A-3-28222. The weight average molecular weight was 100,000, and the glass transition temperature was 310 ° C.
The preform of Resin P-8 was preheated at a pressure of 1 MPa for 30 minutes using a 320 ° C. mold. This preform was press-drawn by the air gap method under conditions of a die plate temperature of 320 ° C., a cooling die temperature of 100 ° C., a pressure of 30 MPa, and a draw ratio of 3 times (area ratio) to produce a film F-1.

(Examples 2 to 4)
Under the same conditions as in Example 1, the pressure was changed to 40, 50, and 100 MPa to perform press stretching to produce films F-2 to F-4.

(Examples 5-7)
At the same pressure (100 MPa) as in Example 4, the draw ratio (area ratio) was changed to 2 times, 4 times, and 5 times to perform press drawing to produce films F-5 to F-7.

(Comparative Example 1)
P-8 was dissolved in methylene chloride, cast onto a glass plate, and dried to produce film H-1.

(Comparative Example 2)
The same preform as in Example 1 was used, the surface resin temperature was set to 320 ° C., and simultaneous biaxial stretching was performed, but the film was broken at a stretch ratio of 2 times (area ratio).

  In the following Examples 8 to 16, a method for producing a film by stretching in a state in which a solvent is contained is described.

(Example 8)
Resin P-8 was dissolved in methylene chloride at 15% by mass to prepare a dope. The film was cast on a glass plate with a doctor blade and dried at 40 ° C. Before completely drying, it was peeled off from the glass plate, cut into a size of 120 mm × 120 mm, and stretched by a simultaneous biaxial stretching machine. The stretching conditions were a resin temperature of 200 ° C., a stretching speed of 100 mm / min (both longitudinal and lateral), a chuck distance of 100 mm, and a stretching ratio of 2.0 times (area ratio). After stretching, the film was dried in vacuum at 100 ° C. for 2 hours, fixed to a metal frame, and heat-treated at 300 ° C. for 1 hour under nitrogen to produce a film F-8.
Each weight before stretching, after stretching and after drying of the film was measured, and the amount of each residual solvent before stretching and after stretching was calculated from the measured values.

(Examples 9 and 10)
In the same manner as in Example 8, the resin P-8 was used and stretched under different stretching conditions to prepare films F-9 and F-10.

(Examples 11-14)
Film F-11-14 was produced by extending | stretching in the state which contained the solvent by operation similar to Example 8 using resin P-32. Methylene chloride and DMAc were used as the solvent. The heat treatment was performed at 300 ° C. for 5 minutes under nitrogen.

(Examples 15 and 16)
Film F-15 and 16 were produced by extending | stretching the state containing the solvent using resin P-30. DMAc was used as the solvent. The heat treatment was performed at 300 ° C. for 1 hour under nitrogen.

(Comparative Examples 3 and 4)
Films H-3 and 4 were produced by using the resin P-32 to produce a dope, cast, and completely dry. Although H-4 was stretched by a simultaneous biaxial stretching machine at a resin temperature of 315 ° C., it was broken at a stretch ratio of 2 times (area ratio).

(Comparative Examples 5 and 6)
Films H-5 and 6 were prepared by using the resin P-30, by preparing a dope, casting and completely drying. H-6 was stretched by a simultaneous biaxial stretching machine at a resin temperature of 370 ° C., but was broken at a stretch ratio of 2 times (area ratio).

(Examination and evaluation)
The weight average molecular weight and glass transition temperature (Tg) of the polymers used in Examples 1 to 16 and Comparative Examples 1 to 6, and the thicknesses of the prepared films F-1 to F-16 and H-1 to H-6 , Linear thermal expansion coefficient, light transmittance at 420 nm, and tensile modulus were measured by the following methods.

<Weight average molecular weight>
Using HLC-8120GPC manufactured by Tosoh Corporation, the weight average molecular weight was determined by polystyrene conversion GPC measurement using tetrahydrofuran or DMF as a solvent in comparison with a polystyrene molecular weight standard product.

<Glass transition temperature (Tg)>
Using a differential scanning calorimeter (DSC6200, manufactured by Seiko Co., Ltd.), the Tg of each film sample was measured in nitrogen at a temperature rising temperature of 10 ° C./min.

<Thickness of film>
The thickness of the film substrate was measured with a dial-type thickness gauge using K402B manufactured by Anritsu Corporation.

<Linear thermal expansion coefficient>
A film sample (19 mm × 5 mm) was prepared and measured using TMA (manufactured by Rigaku Corporation, TMA8310). The measurement speed was 3 ° C./min, and the measurement temperature was 25 ° C. to 250 ° C. The measurement was performed on three samples, and the average value was used.

<Light transmittance>
The light transmittance of the film substrate was measured for the light transmittance at a wavelength of 420 nm using a spectrophotometer (manufactured by Shimadzu Corporation, spectrophotometer UV-3100PC).

<Refractive index difference>
Using an Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.), the in-plane refractive index (Nx and Ny) and the refractive index (Nz) in the thickness direction were measured at a measurement wavelength of 589 nm at 25 ° C. . The in-plane refractive index Nxy was calculated as the average of Nx and Ny ((Nx + Ny) / 2). The refractive index difference was calculated as Nxy−Nz.

<Tensile modulus>
A film sample (1.0 cm × 5.0 cm piece) was prepared, and the tensile modulus was measured using Tensilon (manufactured by Toyo Baldwin Co., Ltd., Tensilon RTM-25) under the condition of a tensile speed of 3 mm / min. Three samples were measured and evaluated by calculating the average value (the sample was used after standing overnight at 25 ° C. and a relative humidity of 60%. The distance between chucks was 3 cm).

  The linear thermal expansion coefficient of the film prepared by the press stretching method was smaller than that of the cast film. In the case of simultaneous tensile biaxial stretching, the film could not be stretched up to twice the stretch ratio (area ratio) and was broken. Succeeded in producing a film with a small coefficient of linear thermal expansion by the press drawing method.

  The linear thermal expansion coefficient of a film that was simultaneously biaxially stretched in tension with the solvent contained and below the Tg of the film was smaller than that of the cast film. In the case of simultaneous tensile biaxial stretching without containing a solvent, the film could not be stretched up to twice the stretch ratio (area ratio) and was broken. A film with a small coefficient of linear thermal expansion was successfully produced by a stretching method in the state of containing a solvent.

(Example 17) Production and evaluation of flat panel display (TN type liquid crystal display device)
1. By DC magnetron sputtering on both surfaces of Formation of the film F-1 to F-16 and H-1, 3, 5 of the gas barrier layer, Si0 ₂ and under a vacuum of a target 500 Pa, an Ar atmosphere, sputtering output 5kW did. The film thickness of the obtained gas barrier layer was 60 nm. The film having the gas barrier layer has a water vapor permeability of 0.1 g / m ² · day or less at 40 ° C. and a relative humidity of 90%, and an oxygen permeability of 0.1 ml / m ² · day at 40 ° C. and a relative humidity of 90%. day or less.

2. Formation of transparent conductive layer ITO (In ₂ O ₃ 95% by mass, Sn0 ₂ 5% by mass) while heating the films F-1 to F-16 and H-1, 3 and 5 on which the gas barrier layer was installed at 100 ° C A transparent conductive layer made of an ITO film having a thickness of 140 nm and an output of 5 kW was provided on one side under a vacuum of 0.665 Pa and in an Ar atmosphere by a DC magnetron sputtering method. The surface electrical resistance of the film provided with the transparent conductive layer at 25 ° C. and 60% relative humidity was 30Ω / □.

3. Heat treatment The films F-1 to F-16 and H-1, 3, 5 on which the transparent conductive layer obtained above was placed were heated from room temperature to 300 ° C assuming a TFT placement process. When the SiO ₂ layer and the ITO layer were observed for cracks after cooling to room temperature, no cracks were observed in F-1 to F-16, but cracks were observed in H-1, 3 and 5.
Films stretched by the press-stretching method and films stretched in a solvent-containing state have a lower in-plane linear thermal expansion coefficient than unstretched films, so there are no cracks in the inorganic layer due to heating. It was.

4). Production of Circular Polarizing Film On the opposite side of the transparent conductive layer of the film substrate produced using Film F-4 of the present invention and Comparative Films F-8 and F-9, JP-A-2000-826705 and JP-A-2002. A λ / 4 plate described in JP-A-131549 was laminated, and a polarizing plate described in JP-A-2002-865554 was further laminated thereon to form a circularly polarizing plate. The angle between the transmission axis of the polarizing film and the slow axis of the λ / 4 plate was set to 45 °.

5. Production of TN type liquid crystal display device On the transparent conductive layer (ITO) side of the glass substrate provided with the film F-4 of the present invention, comparative films F-8 and F-9, and the aluminum reflective electrode formed with fine irregularities. A polyimide alignment film (SE-7992, manufactured by Nissan Chemical Industries, Ltd.) was formed and heat-treated at 200 ° C. for 30 minutes. In the case of using the film F-4 of the present invention, neither an increase in resistance value nor an increase in gas permeability was observed. On the other hand, the resistance values and gas permeability of the films using Comparative Films F-8 and F-9 increased twice or more.
Further, after the rubbing treatment, two substrates (a glass substrate and a plastic substrate) were stacked with a 1.7 μm spacer so that the alignment films face each other. The orientation of the substrate was adjusted so that the rubbing directions of the two alignment films intersected at an angle of 110 °. Liquid crystal (MLC-6252, manufactured by Merck) was injected into the gap between the substrates to form a liquid crystal layer. In this way, a TN liquid crystal cell having a twist angle of 70 ° and a Δnd value of 269 nm was manufactured.
Furthermore, the reflection type liquid crystal display device was produced by laminating the λ / 4 plate and the polarizing plate on the surface of the film substrate opposite to the ITO.
Good images were obtained using the film F-4 of the present invention. On the other hand, in the case of using Comparative Films F-8 and 9, a color caused by a black spot failure (a fine black dot is not displayed on the image layer portion and an image is not displayed) due to a decrease in gas barrier properties, or a crack in the conductive layer. Deviation occurred.

(Example 9) Production and evaluation of organic EL element Organic EL element samples A, B, and C were produced using the film F-4 of the present invention and the comparative example films F-8 and F-9, respectively.
From the transparent electrode layer of the substrate film on which the transparent conductive layer subjected to the heat treatment was formed, aluminum lead wires were connected to form a laminated structure. The surface of the transparent electrode was spin-coated with an aqueous dispersion of polyethylene dioxythiophene / polystyrene sulfonic acid (BAYER, Baytron P: solid content 1.3% by mass), and then vacuum-dried at 150 ° C. for 2 hours to obtain a thickness of 100 nm. The hole transportable organic thin film layer was formed. This was designated as substrate X.
On the other hand, a coating solution for a light-emitting organic thin film layer having the following composition was applied on one side of a temporary support made of 188 μm thick polyethersulfone (Sumilite FS-1300 manufactured by Sumitomo Bakelite Co., Ltd.) using a spin coater. The luminescent organic thin film layer having a thickness of 13 nm was formed on the temporary support by applying and drying at room temperature. This was designated as transfer material Y.

Polyvinylcarbazole (Mw = 63000, manufactured by Aldrich): 40 parts by mass Tris (2-phenylpyridine) iridium complex (orthometalated complex): 1 part by mass Dichloroethane: 3200 parts by mass

  The luminescent organic thin film layer side of the transfer material Y is superimposed on the upper surface of the organic thin film layer of the substrate X, heated and pressurized at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers, and the temporary support is attached. By peeling off, a light-emitting organic thin film layer was formed on the upper surface of the substrate X. This was designated as substrate XY.

Further, a patterned evaporation mask (a mask having a light emitting area of 5 mm × 5 mm) is placed on one side of a polyimide film (UPILEX-50S, manufactured by Ube Industries) having a thickness of 50 μm cut into 25 mm square, and about 0. Al was evaporated in a reduced pressure atmosphere of 1 mPa to form an electrode having a film thickness of 0.3 μm. Using an Al ₂ O ₃ target by DC magnetron sputtering, the Al ₂ O ₃ was deposited in the same pattern as the Al layer and the thickness of 3 nm. An aluminum lead wire was connected from the Al electrode to form a laminated structure. A coating solution for an electron transporting organic thin film layer having the following composition is coated on the obtained laminated structure using a spin coater coating machine, and vacuum dried at 80 ° C. for 2 hours, thereby transporting an electron having a thickness of 15 nm. An organic thin film layer was formed. This was designated as substrate Z.

Polyvinyl butyral 2000L (Mw = 2000, manufactured by Denki Kagaku Kogyo Co., Ltd.): 10 parts by mass 1-butanol: 3500 parts by mass Electron transporting compound having the following structure: 20 parts by mass

  Using the substrates XY and Z, the electrodes are stacked so that the electrodes face each other with the light-emitting organic thin film layer interposed therebetween, and heated and pressurized at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers, The organic EL element samples A, B, and C were obtained by bonding.

  The obtained organic EL element samples A, B, and C were applied to the organic EL element using a source measure unit 2400 type (manufactured by Toyo Technica Co., Ltd.). It was confirmed that Sample A of the present invention emitted light. On the other hand, Comparative Samples B and C emitted light for a moment but stopped emitting light immediately.

  The film of the present invention is provided with various functional layers as necessary, and flat panel displays such as liquid crystal, plasma display, organic electroluminescence (EL), inorganic electroluminescence, fluorescent display tube, light emitting diode, field emission type, etc. It can be used for the image display apparatus. Moreover, the film of this invention can be utilized also for uses, such as a solar cell and a touch panel.

Claims (13)

  The glass transition temperature (Tg) is 250 ° C. or higher, the linear thermal expansion coefficient in the measurement range from 25 ° C. to 250 ° C. is −20 to 40 ppm / ° C., and the light transmittance at 420 nm is 70% or higher. Characteristic film. 2. The film according to claim 1, comprising a polymer containing a structure represented by the following general formula (1), (2) or (3).

[In general formulas (1) and (2), ring α and ring β each independently represent a monocyclic or polycyclic ring, and are linked by one quaternary carbon. In the general formula (1), the linking group is bonded to any two carbons of the ring α. In the general formula (2), the linking group is bonded to any one carbon of the ring α and any one carbon of the ring β. In general formula (3), two rings γ and δ each independently represent a monocyclic or polycyclic ring, and are connected to one quaternary carbon on ring δ. The linking group is bonded to any carbon of ring γ. ]   The film according to claim 1 or 2, wherein the average refractive index Nxy in the film plane is 0.02 or more larger than the refractive index Nz in the thickness direction.   The method for producing a film according to claim 1, comprising a step of stretching a film made of a resin having a glass transition temperature (Tg) of 250 ° C. or higher.   The manufacturing method according to claim 4, wherein the film is stretched by a press stretching method.   The manufacturing method according to claim 4, wherein the film is stretched by a biaxial stretching method.   The production method according to claim 4, wherein the film is stretched in a state where the film contains a solvent.   A film produced by the production method according to claim 4.   The film with a gas barrier layer which has a gas barrier layer on the film as described in any one of Claims 1-3 and 8.   The film with a transparent conductive layer which has a transparent conductive layer on the film as described in any one of Claims 1-3, 8, and 9.   The film with TFT which has TFT on the film as described in any one of Claims 1-3 and 8-10.   The image display apparatus which used the film as described in any one of Claims 1-3 and 8-11 as a board | substrate.   The image display device according to claim 12, wherein the image display device is a liquid crystal display device or an organic electroluminescence display device.