JP2006219612A - Optical film and image-display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film having excellent heat resistance and light resistance, and to provide a liquid crystal display device using the same. <P>SOLUTION: THe optical film comprises a polymer having a glass transition temperature of ≥250°C, and at least one deterioration preventing agent selected from the group consisting of (1) a carbon free radical scavenger, (2) a primary antioxidizing agent having an abilily to donate a hydrogen free radical to a peroxy free radical and (3) a secondary antioxidizing agent having a reduction function to a peroxide. And the liquid crystal display device uses the optical film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an optical film excellent in heat resistance and weather resistance, and an image display device excellent in display quality produced using the optical film.
More specifically, the present invention relates to an optical film that is less susceptible to deterioration such as coloring, deformation, and decrease in mechanical strength due to heating when a functional layer such as a semiconductor layer is placed on the film. Various image display elements, particularly flexible The present invention relates to a transparent film useful as a substrate such as an organic electroluminescence element (hereinafter referred to as “organic EL element”), and an image display device produced using the transparent film.

  In recent years, in the field of flat panel displays such as liquid crystal display devices and organic electroluminescence elements, replacement of a substrate from glass to plastic has been studied in order to improve breakage resistance, reduce weight, and reduce thickness. In particular, display devices for mobile information communication devices such as mobile phones, electronic notebooks, laptop computers, and portable information terminals have strong demands for plastic substrates.

  The plastic substrate needs to have conductivity. Therefore, in recent years, a metal film such as a semiconductor film such as an oxide of indium oxide, tin oxide, or a tin-indium alloy, an oxide film of gold, silver, or a palladium alloy, or the semiconductor film and the metal is formed on a plastic film. Research has been conducted on the use of a plastic substrate on which a transparent conductive layer made of a composite film combined with a film is formed as an electrode substrate of a display element. Specifically, a heat-resistant amorphous polymer (for example, modified polycarbonate (modified PC: see, for example, Patent Document 1), polyethersulfone (PES: see, for example, Patent Document 2), or cycloolefin copolymer (for example, Patent Document 3). There is known a plastic substrate in which a transparent conductive layer and further a gas barrier layer are laminated on a plastic film made of (see).

  However, even if the heat-resistant plastic film as described above is used, a plastic substrate having sufficient heat resistance cannot be obtained. That is, when a conductive layer is formed on these heat-resistant plastic films and then exposed to a temperature of 150 ° C. or higher for providing an alignment film or the like, there is a problem that the conductivity and gas barrier properties are greatly lowered.

Further, in recent years, development of a technique for forming an active matrix image element on a plastic substrate has been studied. In this technique, it is necessary to expose the substrate to a higher temperature in the TFT installation process, and a plastic substrate having a higher level of heat resistance is required.
On the other hand, in the TFT installation process, the temperature reduction of the silicon semiconductor film manufacturing process that requires a high temperature is also being studied. As a method for lowering the temperature of the silicon semiconductor film manufacturing step, for example, a method of forming a polycrystalline silicon film at a temperature of 300 ° C. or lower by plasma decomposition of a gas containing SiH ₄ (see Patent Document 4), A method of forming a semiconductor layer in which amorphous silicon and polycrystalline silicon are mixed on a polymer substrate by irradiating an energy beam (see Patent Document 5), providing a thermal buffer layer, and irradiating a pulse laser beam to 300 A method of forming a polycrystalline silicon semiconductor layer on a plastic substrate at a temperature of ℃ or lower (see Patent Document 6) is known.

  However, although these methods can form TFTs at 300 ° C. or lower, there is a problem that the configuration and apparatus are complicated and expensive. Therefore, it is actually desired to form TFTs at a high temperature of 300 ° C. or higher, and it is required to provide a plastic substrate having heat resistance of 300 ° C. or higher. Also, from the viewpoint of stably expressing the electrical characteristics of TFT, TFT formation at a higher temperature is required, and it is strongly desired to provide a plastic substrate having excellent heat resistance.

Patent Document 7 and Patent Document 8 describe a polyarylate film derived from 9,9-bis (4-hydroxyphenyl) fluorene (hereinafter also referred to as “bisphenolfluorene”), isophthalic acid and terephthalic acid. is there. Patent Document 9 describes a polyarylate film derived from alkyl-substituted bisphenolfluorene, isophthalic acid and terephthalic acid. Furthermore, Patent Document 10 describes a polyarylate film derived from bisphenolfluorene in which the ortho position of phenol is substituted with halogen or the like.
All of these polyarylates can be synthesized from inexpensive raw materials, and have a glass transition temperature (Tg) of around 300 ° C. or higher, and can provide a flexible film excellent in transparency and elongation at break. However, even with these films, the performance is not sufficiently satisfactory for the above-mentioned heat resistance requirement required for plastic substrates. When heated for a long time at a temperature of about 300 ° C. in the TFT installation process, the polymer partially decomposes. There was a problem that yellowing of the film occurred. In addition, these polymers are yellowed even when irradiated with ultraviolet light for a long time, and improvement has been desired from the viewpoint of light resistance. In these patent documents, there is no specific description regarding the combined use of the deterioration inhibitor.

JP 2000-227603 A (all pages) JP 2000-284717 A (all pages) JP 2001-150584 A (all pages) JP-A-7-81919 (all pages) Japanese National Patent Publication No. 10-512104 (all pages) Japanese Patent Laid-Open No. 11-102867 (all pages) JP-A-57-192432 (all pages) JP-A-3-28222 (all pages) International Publication No. WO99 / 18141 (all pages) JP 2002-145998 A (all pages)

  The present invention has been made in view of the above problems, and a first object of the present invention is to provide an optical film having excellent heat resistance and light resistance, and a second object is to provide an image using the optical film. An object is to provide an image display device having excellent quality.

  As a result of intensive investigation of the TFT installation process on the high heat-resistant film, the present inventor is extremely effective to add a specific deterioration preventing agent for the problem that the deterioration phenomenon such as coloring of the film often occurs even at a temperature below Tg. Thus, it has been found that an image display device with excellent display quality can be provided, and the present invention has been completed.

That is, the said subject of this invention is achieved by the following means.
(1) An optical film made of a polymer having a glass transition temperature of 250 ° C. or higher, (1) a carbon radical scavenger, (2) a primary antioxidant having a hydrogen radical donating ability for peroxy radicals, and (3 An optical film comprising at least one kind of deterioration inhibitor selected from a secondary antioxidant having a reducing action on peroxide).

  (2) The optical film as described in (1) above, which contains at least the carbon radical scavenger as the degradation inhibitor.

〔一般式（１）中、Ｒ¹は水素原子または炭素数１〜１０のアルキル基を表し、Ｒ²およびＲ³は、それぞれ独立して炭素数１〜８のアルキル基を表す。〕 (3) The optical film as described in (1) or (2) above, wherein the carbon radical scavenger is a compound represented by the following general formula (1).

[In General Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ² and R ³ each independently represents an alkyl group having 1 to 8 carbon atoms. ]

  (4) The above-mentioned (1), wherein the deterioration inhibitor contains at least the primary antioxidant, and the primary antioxidant is a phenol-based antioxidant or an amine-based antioxidant. The optical film as described in any one of-(3).

  (5) The above-described deterioration inhibitor, which contains at least the secondary antioxidant, and the secondary antioxidant is a sulfur-based antioxidant or a phosphorus-based antioxidant. The optical film as described in any one of 1) to (4).

  (6) The optical film as described in any one of (1) to (5) above, wherein the polymer having a glass transition temperature of 250 ° C. or higher is polyarylate, polyamide or polyimide.

一般式（３）

〔一般式（３）中、環βおよび環γは単環式または多環式の環を表す。２つの環γは、それぞれ同じであっても異なっていてもよく、環β上の１つの４級炭素において連結されている。〕 (7) The polymer having a glass transition temperature of 250 ° C. or higher has a spiro structure represented by the following general formula (2) or a cardo structure represented by the following general formula (3): The optical film as described in any one of (6).

General formula (3)

[In general formula (3), ring β and ring γ represent a monocyclic or polycyclic ring. The two rings γ may be the same or different, and are connected at one quaternary carbon on the ring β. ]

(8) An optical film comprising a gas barrier layer on the optical film according to any one of (1) to (7) above.
(9) An optical film comprising a transparent conductive layer on the optical film described in any one of (1) to (8) above.

  (10) An image display device comprising the optical film according to any one of (1) to (9) above.

  According to the present invention, an optical film having excellent heat resistance and light resistance can be provided. In addition, according to the present invention, it is possible to provide an image display device with excellent image quality.

The present invention is described in detail below. 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.
<Optical film>
The optical film of the present invention is an optical film made of a polymer having a glass transition temperature of 250 ° C. or higher, (1) a carbon radical scavenger, (2) a primary antioxidant having a hydrogen radical donating ability for peroxy radicals, And (3) containing at least one degradation inhibitor selected from secondary antioxidants having a reducing action on peroxides. Since the optical film of the present invention is excellent in heat resistance and light resistance, even if it is exposed to a high temperature at the time of laminating a functional layer (such as an inorganic semiconductor layer) on the film, there is little deterioration such as coloring and deformation. Moreover, a high quality image display apparatus can be provided by using this as a base material.

  In the present invention, the optical film means a film having a thickness of 10 to 700 μm, a light transmittance at 420 nm of 40% or more, and a total light transmittance of 60% or more.

<Polymer for optical film>
In the present invention, the polymer constituting the base film is a polymer having a glass transition temperature of 250 ° C. or higher, and is preferably a transparent resin. Specifically, polyarylate (for example, those described in JP-A Nos. 2002-145998 and 2000-243144), polyamide (for example, those described in JP-A-62-230823), polyimide, and the like (For example, those described in JP-A Nos. 2002-322279 and 7-304870), polybenzoxazole (for example, those described in JP-A No. 11-322929), polycarbonate (for example, JP-A No. 2003-221986) And those described in the following compound examples). Among these, as the polymer in the present invention, polyarylate, polyamide or polyimide is preferable, and polyarylate is particularly preferable.

  Furthermore, as a polymer having a glass transition temperature of 250 ° C. or higher used in the optical film of the present invention, a polymer having a spiro structure represented by the following general formula (2) or a cardo structure represented by the following general formula (3) From the viewpoints of transparency, solubility, and heat resistance, a polymer having an is preferred.

  In the general formula (2), the ring α represents a monocyclic or polycyclic ring, and the two rings are connected by a spiro bond. Further, the two rings α may be the same or different.

  In the general formula (3), ring β and ring γ represent a monocyclic or polycyclic ring. The two rings γ may be the same or different, and are connected at one quaternary carbon on the ring β.

Examples of the ring α in the general formula (2) include an indane ring, a chroman ring, a 2,3-dihydrobenzofuran ring, an indoline ring, a tetrahydropyran ring, a tetrahydrofuran ring, a dioxane ring, a cyclohexane ring, and a cyclopentane ring. Can be mentioned.
Examples of the ring β in the general formula (3) include a fluorene ring, an indandione ring, an indanone ring, an indene ring, an indane ring, a tetralone ring, an anthrone ring, a cyclohexane ring, and a cyclopentane ring.
Examples of the ring γ in the general formula (3) include benzene ring, naphthalene ring, anthracene ring, fluorene ring, cyclohexane ring, cyclopentane ring, pyridine ring, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, benzo Examples include thiazole ring, indane ring, chroman ring, indole ring, α-pyrone ring and the like.

  Preferred examples of the polymer having a spiro structure represented by the general formula (2) include a polymer having a spirobiindane structure represented by the following general formula (4) in a repeating unit, and represented by the following general formula (5). And a polymer containing a spirobibenzofuran structure represented by the following general formula (6) in the repeating unit.

In General Formula (4), R ³¹ and R ³² each independently represent a hydrogen atom or a substituent. R ³³ represents a substituent. Each of R ³¹ , R ³² and R ³³ may be linked to form a ring. m and n represent an integer of 0 to 3.
Examples of preferred substituents represented by R ³¹ , R ³² and R ³³ include a halogen atom, an alkyl group and an aryl group. More preferred examples of R ³¹ and R ³² are a hydrogen atom, a methyl group and a phenyl group, and more preferred examples of R ³³ are a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, an isopropyl group, a tert-butyl group, It is a phenyl group.

In general formula (5), ^R41 represents a hydrogen atom or a substituent. R ⁴² represents a substituent. R ⁴¹ and R ⁴² may be connected to each other to form a ring. m and n represent an integer of 0 to 3.
Examples of preferred substituents represented by R ⁴¹ and R ⁴² include a halogen atom, an alkyl group, and an aryl group. More preferred examples of R ⁴¹ are hydrogen atom, methyl group, and phenyl group, and more preferred examples of R ⁴² are hydrogen atom, chlorine atom, bromine atom, methyl group, isopropyl group, tert-butyl group, and phenyl group. is there.

In the general formula (6), R ⁵¹ represents a hydrogen atom or a substituent. R ⁵² represents a substituent. R ⁵¹ and R ⁵² may be connected to each other to form a ring. m and n represent an integer of 0 to 3.
Examples of preferred substituents represented by R ⁵¹ and R ⁵² include a halogen atom, an alkyl group, and an aryl group. More preferred examples of R ⁵¹ are hydrogen atom, methyl group and phenyl group, and more preferred examples of R ⁵² are hydrogen atom, chlorine atom, bromine atom, methyl group, isopropyl group, tert-butyl group and phenyl group.

  Moreover, the polymer which has a fluorene structure represented by the following general formula (7) in a repeating unit as a preferable example of the polymer which has a cardo structure represented by the said General formula (3) can be mentioned.

In general formula (7), R ⁶¹ and R ⁶² each independently represent a substituent. R ⁶¹ and R ⁶² may be connected to each other to form a ring. j represents an integer of 1 to 4; k represents an integer of 0 to 4. Examples of preferred substituents represented by R ⁶¹ and R ⁶² are a halogen atom, an alkyl group, and an aryl group. More preferred examples of R ⁶¹ and R ⁶² are a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, an isopropyl group, a tert-butyl group, and a phenyl group.

  The polymer containing the structure represented by the general formulas (3) to (7) in the repeating unit is a polymer linked by various bonding methods such as polycarbonate, polyarylate, polyamide, polyimide, polybenzoxazole, and polyurethane. However, polyarylate, polyamide, and polyimide derived from a bisphenol compound having a structure represented by the general formulas (3) to (7) are preferable, and polyarylate is particularly preferable.

  Although the preferable specific example (exemplary compound P-1 to P-42) of the polymer which can be used suitably for the optical film of this invention is given to the following, this invention is not limited to these.

  The polymer in this invention may be used independently, and may be used in mixture of multiple types. Moreover, a homopolymer may be sufficient and the copolymer which combined multiple types of structure may be sufficient. In many cases, the copolymer is improved in terms of solubility and transparency.

  The preferred molecular weight of the polymer in the present invention is 10,000 to 500,000 in terms of weight average molecular weight, more preferably 20,000 to 300,000, and particularly preferably 30,000 to 200,000. If the molecular weight is too low, film formation may be difficult or mechanical properties may be reduced. If the molecular weight is too high, it may be difficult to control the molecular weight for synthesis, or the solution may be too viscous to be handled. In addition, the molecular weight of the polymer in this invention can also be judged on the basis of a corresponding viscosity.

  As the polymer used in the optical film of the present invention, it is also preferable to use a crosslinked resin from the viewpoint of solvent resistance, heat resistance and the like in addition to the above-described polymer (thermoplastic resin). Examples of the crosslinked resin include a thermosetting resin and a radiation curable resin, and these various known resins can be used without particular limitation.

  Examples of the thermosetting resin include, for example, phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, diallyl phthalate resin, furan resin, bismaleimide resin, cyanate resin, and the like.

  The thermosetting resin can be crosslinked without particular limitation as long as it is a reaction that forms a covalent bond. For example, a polyalcohol compound and a polyisocyanate compound are used at room temperature so as to form a urethane bond. A system in which the reaction proceeds with no particular limitation can be used. However, such a system often has a problem of pot life before film formation, and is usually used as a two-component mixed type in which a polyisocyanate compound is added immediately before film formation. On the other hand, when the system in which the reaction proceeds at room temperature is used as a one-pack type, it is effective to protect functional groups involved in the crosslinking reaction, and these are also commercially available as block type curing agents. Commercially available block type curing agents include “B-882N” manufactured by Mitsui Takeda Chemical Co., Ltd., “Coronate 2513” manufactured by Nippon Polyurethane Industry Co., Ltd. (above block polyisocyanate), “Cymel manufactured by Mitsui Cytec Co., Ltd.” 303 "(methylated melamine resin) and the like are known. Further, as the block type curing agent, a blocked carboxylic acid such as the following B-1 that protects a polycarboxylic acid that can be used as a curing agent for an epoxy resin is also known.

  The radiation curable resins are roughly classified into radical curable resins and cationic curable resins. As the curable component of the radical curable resin, a compound having a plurality of radically polymerizable groups in the molecule is used, and a typical example is a compound having 2 to 6 acrylate groups in the molecule. A compound called a functional acrylate monomer and a compound having a plurality of acrylate groups in a molecule called urethane acrylate, polyester acrylate, and epoxy acrylate can be mentioned.

  As a typical curing method of the radical curable resin, there are a method of irradiating an electron beam and a method of irradiating ultraviolet rays. Usually, in the method of irradiating with ultraviolet rays, a polymerization initiator that generates radicals upon irradiation with ultraviolet rays is added. In addition, the said radical curable resin can also be used as a thermosetting resin, if the polymerization initiator which generate | occur | produces a radical by heating is added.

  As the curable component of the cationic curable resin, a compound having a plurality of cationic polymerizable groups in the molecule is used. As a typical curing method, a photoacid generator that generates an acid upon irradiation with ultraviolet rays is added. And a method of curing by irradiating ultraviolet rays. Examples of the cationically polymerizable compound include a compound containing a ring-opening polymerizable group such as an epoxy group and a compound containing a vinyl ether group.

  The thermosetting resin and the radiation curable resin may be used by mixing a plurality of types of resins, respectively, and a thermosetting resin and a radiation curable resin may be used in combination. Further, a crosslinkable resin and a resin having no crosslinkable group may be mixed and used.

  Furthermore, when the above-mentioned crosslinkable resin is mixed and used as the polymer in the present invention, the solvent resistance, heat resistance, optical properties, and toughness of the resulting optical film can be improved. In the present invention, it is also possible to introduce a crosslinkable group into the polymer of the present invention. In this case, you may have a crosslinkable group in any site | part in a polymer principal chain terminal, a polymer side chain, and a polymer principal chain. Moreover, you may produce an optical film, without using together said general purpose crosslinkable resin.

<Deterioration inhibitor>
In the optical film of the present invention, a polymer having a glass transition temperature of 250 ° C. or higher is used, and a deterioration preventing agent is added for the purpose of reducing deterioration phenomena such as coloring, deformation, and mechanical strength reduction due to thermal decomposition. .
In the degradation process of polymers, 1) generation of carbon radicals by bond cleavage, 2) generation of peroxy radicals by reaction of carbon radicals with oxygen, 3) processes of peroxide generation by extraction of hydrogen radicals by peroxy radicals, etc. There are various degradation pathways due to each active species. Therefore, in order to prevent deterioration of the polymer, it is effective to add a deterioration inhibitor that inactivates the active species.
In the present invention, (1) a carbon radical scavenger, (2) a primary antioxidant having a hydrogen radical donating ability to peroxy radicals, and (3) a secondary antioxidant having a reducing action on peroxides, At least one kind of degradation inhibitor selected is contained in the polymer in the present invention.

(1) Carbon radical scavenger A carbon radical scavenger that quickly traps and inactivates carbon radicals generated by decomposition is effective for the process 1) above. In the present invention, the “carbon radical scavenger” has a group (for example, an unsaturated group such as a double bond or a triple bond) that allows a carbon radical to rapidly undergo an addition reaction, and is followed by polymerization or the like after the addition of the carbon radical. It means a compound that gives a stable product in which no reaction takes place.
Examples of the carbon radical scavenger include a compound having a group capable of reacting rapidly with a carbon radical (unsaturated group such as (meth) acryloyl group and aryl group) in the molecule and a group capable of inhibiting radical polymerization such as phenol. A phenol compound represented by the following general formula (1) is particularly preferable.

〔一般式（１）中、Ｒ¹は水素原子または炭素数１〜１０のアルキル基を表し、Ｒ²およびＲ³は、それぞれ独立して炭素数１〜８のアルキル基を表す。〕

[In General Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ² and R ³ each independently represents an alkyl group having 1 to 8 carbon atoms. ]

In general formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and particularly preferably a hydrogen atom or a methyl group. .
R ² and R ³ each independently represents an alkyl group having 1 to 8 carbon atoms, and may be linear or have a branched structure or a ring structure. R ² and R ³ are preferably a structure represented by “* —C (CH ₃ ) ₂ —R ′” containing a quaternary carbon (* represents a connecting site to an aromatic ring, and R ′ has 1 carbon atom) Represents an alkyl group of ˜5).
R ² is more preferably a tert-butyl group, a tert-amyl group or a tert-octyl group. R ³ is more preferably a tert-butyl group or a tert-amyl group.
As the compound represented by the general formula (1), commercially available products include “Sumilizer GM, Sumilizer GS” (both trade names, manufactured by Sumitomo Chemical Co., Ltd.) and the like.

  Specific examples (I-1 to I-18) of the carbon radical scavenger are illustrated below, but the present invention is not limited thereto.

2) Primary antioxidant A primary antioxidant having the ability to donate hydrogen radicals to peroxy radicals is effective for the process 2) above. In the present invention, the “primary antioxidant having the ability to donate a hydrogen radical to a peroxy radical” is a compound having at least one hydrogen atom in the molecule that is rapidly extracted by the peroxy radical, and is a hydroxyl group or a primary or An aromatic compound substituted with a secondary amino group is preferable, and a phenol derivative or a diarylamine derivative having an alkyl group at the ortho position is more preferable. When the nucleophilicity of amine-based antioxidants such as polyarylate is a problem, phenol-based antioxidants are preferred.
Specific examples (J-1 to J-18) of the primary antioxidant are shown below, but the present invention is not limited thereto.

3) Secondary antioxidant A secondary antioxidant having a reducing action on peroxide is effective for the process of 1) above. In the present invention, the “secondary antioxidant having a reducing action on peroxide” means a reducing agent that rapidly reduces peroxide to convert it to a hydroxyl group.
The secondary antioxidant having a reducing ability for peroxide is preferably a sulfur-based antioxidant or a phosphorus-based antioxidant.
As said sulfur type antioxidant, the thioether type compound represented by following General formula (8) is preferable.

Formula (8): R ³ —S—R ⁴

In the general formula (8), R ³ and R ⁴ represent a substituent. The substituent is preferably an alkyl group or CH ₂ CH ₂ CO ₂ R (R is an alkyl group having 10 to 20 carbon atoms), and more preferably CH ₂ CH ₂ CO ₂ R (R is carbon 10 to 20). An alkyl group), particularly preferably CH ₂ CH ₂ CO ₂ R (R is an alkyl group having 12 to 18 carbon atoms). R ³ and R ⁴ can be linked to R ³ and R ⁴ of one skeleton via a divalent or higher-valent organic group or a single bond, and the sulfur-based antioxidant is represented by the general formula (8 ) May be a compound having a plurality of skeletons in one molecule.

  As said phosphorus compound antioxidant, the compound represented by following General formula (9) is preferable.

In the general formula (9), R ^{5 to} R ⁷ each independently represent a substituent. R ⁷ is preferably an alkyl group or an aryl group, more preferably an aryl group having 6 to 20 carbon atoms, and particularly preferably a phenyl group. R ⁵ and R ⁶ are preferably an alkyl group, an aryl group, an alkoxy group, and an aryloxy group, more preferably an aryl group, an alkoxy group, and an aryloxy group, and particularly preferably an aryloxy group. is there. Further, the phosphorus compound antioxidant may be a compound in which a plurality of partial structures of the general formula (9) are present in one molecule.
Specific examples of the secondary antioxidant include the following compounds (K-1 to K-20), but the present invention is not limited thereto.

The above deterioration inhibitors may be used alone, but for example, carbon radical scavenger / primary antioxidant, carbon radical scavenger / secondary antioxidant, carbon radical scavenger / primary antioxidant / secondary antioxidant. A combination of a plurality of types such as an agent and a primary antioxidant / secondary antioxidant may be used, and a combination of a plurality of types is preferred from the viewpoint of preventing deterioration due to a synergistic effect.
Addition of a carbon radical scavenger is particularly effective from the viewpoint of preventing deterioration due to heating in the process of installing the inorganic functional layer on the optical film.

The addition amount of the deterioration inhibitor is preferably 0.001 to 5% by mass, more preferably 0.01 to 2% by mass, and 0.01 to 1% by mass for each type. Particularly preferred. In addition, the total amount of the deterioration inhibitor in the polymer of the present invention is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, It is especially preferable that it is -2 mass%.
In the present invention, it is more preferable to contain at least a carbon radical scavenger, and when a primary antioxidant is used in combination, it may be added in a range of 0.001 to 3 equivalents relative to the carbon radical scavenger. The addition is more preferably in the range of 0.01 to 1 equivalent, and particularly preferably in the range of 0.05 to 0.5 equivalent. Moreover, when using secondary antioxidant together, it is preferable to add in the range of 0.001-1 equivalent with respect to a carbon radical scavenger, and adding in the range of 0.01-0.5 equivalent. More preferably, it is particularly preferable to add in the range of 0.05 to 0.3 equivalents.

<Optical film>
Next, the optical film of the present invention will be described.
The optical film of the present invention is an optical film formed by adding the above-mentioned degradation inhibitor to the above polymer.
As a method for forming the polymer into a film or sheet shape, a known method can be adopted, and a solution casting method is preferable. 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. 2607704, U.S. Pat. No. 2739069, U.S. Pat. No. 2739070, British Patent No. 640731, British Patent No. 736892, Japanese Examined Patent Publication No. 45-4554, Japanese Examined Patent Publication No. 49-5614 There are descriptions in Japanese Laid-Open Patent Publication Nos. 60-176834, 60-203430, and 62-1115035. As an example of the manufacturing apparatus manufactured by the solution casting method, the manufacturing apparatus described in Japanese Patent Laid-Open No. 2002-189126, paragraphs [0061] to [0068], FIG. 1 and FIG. However, the manufacturing apparatus that can be used in the present invention is not limited to these.

  In the solution casting method, the polymer and the deterioration inhibitor are dissolved in a solvent and used. Any solvent may be used as long as it dissolves these, but a solvent capable of dissolving at least 10% by mass of the solid content at 25 ° C. is particularly preferable. The solvent used preferably has a boiling point of 200 ° C. or lower, more preferably 150 ° C. or lower. When the boiling point is high, the solvent may be insufficiently dried and may remain in the film. Moreover, it is also possible to mix a poor solvent in the range which does not impair the solubility of a polymer, and in this case, it may be advantageous in terms of stripping after the solution casting and a drying speed.

Solvents that can be used to dissolve the polymer include methylene chloride, chloroform, tetrahydrofuran, 1,4-dioxane, benzene, cyclohexane, toluene, xylene, anisole, γ-butyrolactone, benzyl alcohol, isophorone, cyclohexanone, cyclohexane. Examples include pentanone, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, ethyl acetate, acetone, chlorobenzene, dichlorobenzene, dimethylformamide, methanol, and ethanol. However, the solvent that can be used in the present invention is not limited thereto.
In addition, two or more of the above solvents may be used as a mixture, and it is preferable to use a mixed solvent from the viewpoint of achieving both dryness and solubility. In addition, the use of a mixed solvent is preferred because the transparency of the optical film of the present invention may be improved.

  The concentration of the polymer in the solution used for solution casting is preferably 5 to 60% by mass, more preferably 10 to 40% by mass, and still more preferably 10 to 30% by mass. If the concentration is too low, the viscosity may be low and it may be difficult to adjust the thickness. If the concentration is too high, the film formability may be poor and unevenness may be increased. Moreover, the transmittance | permeability of the optical film of this invention and the impurity in a film can be reduced by filtering a solution as needed before solution casting.

  The method for casting the above 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.

  After the solution casting, the temperature at which the coating film is dried to skip the solvent varies depending on the boiling point of the solvent used, but is preferably dried in two stages. For example, as a first step, drying is performed at 30 to 100 ° C. until the mass concentration of the solvent is preferably 10% or less, more preferably 5% or less. Next, as a second step, the film is peeled off from the flat plate or roll and dried in a temperature range of 60 ° C. or higher and lower than the glass transition temperature of the polymer. In addition, when peeling a film from a flat plate or a roll, you may peel immediately after completion | finish of drying of a 1st step, and you may peel, after cooling a film once.

If the optical film of the present invention is insufficiently dried by heating, the amount of residual solvent increases. In addition, excessive heating causes thermal decomposition of the polymer and increases the amount of residual monomer. Furthermore, rapid drying by heating causes rapid vaporization of the contained solvent, and causes defects such as bubbles in the film. The amount of the solvent remaining in the optical film of the present invention is preferably 2000 ppm or less, more preferably 1000 ppm or less, and particularly preferably 100 ppm or less. If the amount of the remaining solvent is too large, the film surface characteristics may be deteriorated to adversely affect the surface treatment or the like, or the performance of the functional film provided with a conductive film, a semiconductor film or the like may be deteriorated.
The amount of the solvent remaining in the optical film of the present invention can be quantified using a known method such as gas chromatography.

  The optical film of the present invention is preferably produced by continuously casting the solution onto a rotating drum or band, stripping off, and drying, and winding it into a roll. As described above, when the optical film of the present invention is mechanically conveyed, it is preferable that the film has high mechanical strength. As a measure of the mechanical strength, the breaking stress and breaking elongation obtained from the tensile test of the film can be used. Although the preferable mechanical strength depends on the conveying device, it cannot be generally specified, but the breaking stress is preferably 50 MPa or more, more preferably 80 MPa or more, and further preferably 100 MPa or more. In addition, the rupture elongation of the film varies depending on the sample preparation conditions and the like, but the reliability is low. However, it is preferably 5% or more, more preferably 10% or more, and further preferably 15% or more.

  The optical film of the present invention may be stretched. By stretching the film, the linear thermal expansion of the film can be reduced, the mechanical strength such as the bending strength can be improved, and the handleability is improved. In particular, those having an orientation release stress in the stretching direction (ASTMD1504; hereinafter sometimes referred to as “ORS”) of 0.3 to 3 GPa are preferable because of good mechanical strength. ORS is an internal stress generated by stretching that is frozen in a stretched film or sheet.

For stretching the optical film of the present invention, a known stretching method can be employed. For example, they are described in JP-A-62-115035, JP-A-4-152125, JP-A-4-284221, JP-A-4-298310, JP-A-48271, and the like. The method can be adopted. When the polymer used in the optical film of the present invention has a glass transition temperature of 300 ° C. or higher, it is difficult to perform stretching only by heating, but stretching in a state containing a solvent is possible.
In this case, it is preferable to stretch the film in the course of drying, for example, roll uniaxial stretching between a temperature 10 ° C. higher than the glass transition temperature (Tg) and a temperature 50 ° C. higher than the glass transition temperature (Tg). The film can be stretched by a method, a tenter uniaxial stretching method, a simultaneous biaxial stretching method, a sequential biaxial stretching method, or an inflation method.

The stretch ratio of the film is preferably 1.1 to 5.0 times, more preferably 1.1 to 3.5 times, and particularly preferably 1.1 to 2.0 times. In addition, stretching may be performed in a single stage or in multiple stages. When stretching is performed in multiple stages, the product of each stretching ratio may be within this range.
The stretching speed is preferably 5% / min to 1000% / min, and more preferably 10% / min to 500% / min.

  Stretching is preferably performed by a heat roll and / or a radiant heat source (such as an IR heater) or warm air. Moreover, you may provide a thermostat in order to improve the uniformity of temperature. When performing uniaxial stretching by roll stretching, it is preferable that L / W which is ratio of the distance (L) between rolls and the film width (W) of this optical film is 2.0-5.0.

  Moreover, it is preferable to perform a preheating process before extending | stretching. Further, heat treatment may be performed after the film is stretched. The heating temperature in these heat treatments is preferably 20 to 10 ° C. higher than the glass transition temperature of the optical film, and the heat treatment time is preferably 1 second to 3 minutes. The heating method may be zone heating or partial heating using an infrared heater.

  The optical film of the present invention may contain a metal oxide and / or a metal complex oxide and a metal oxide obtained by a sol-gel reaction. By containing these, heat resistance and solvent resistance can be imparted to the optical film of the present invention, similarly to the above-described crosslinked resin. Furthermore, resin modifiers such as plasticizers, dyes and pigments, antistatic agents, ultraviolet absorbers, inorganic fine particles, peeling accelerators, leveling agents, and lubricants may be added as long as the effects of the present invention are not impaired. Also good.

As for the thickness of the optical film of this invention, 30 micrometers-700 micrometers are preferable, More preferably, they are 40 micrometers-200 micrometers, More preferably, they are 50 micrometers-150 micrometers. Further, in any case, the haze value is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less.
Further, the light transmittance at 420 nm is preferably 50% or more, more preferably 60% or more, and further preferably 70% or more. The total light transmittance is preferably 70% or more, more preferably 80% or more, and still more preferably 85% or more.

  The heat resistant temperature of the optical film of the present invention is preferably high, and the glass transition temperature by DSC measurement can be used as a guide. In this case, a preferable glass transition temperature is 250 ° C. or higher, more preferably 300 ° C. or higher, and particularly preferably 320 ° C. or higher.

  The linear thermal expansion coefficient of the optical film of the present invention is preferably -30 to 60 ppm / ° C, more preferably -20 to 50 ppm / ° C in the range of 0 to 200 ° C, more preferably in the range of 0 to 300 ° C. Is more preferable, and −10 to 40 ppm / ° C. is particularly preferable.

  On the surface of the optical film of the present invention, other layers are formed depending on the application, or treatment such as saponification, corona treatment, flame treatment, glow discharge treatment, etc. on the film substrate surface in order to enhance the adhesion with the parts. Can be applied. Further, an adhesive layer or an anchor layer may be provided on the film surface. Depending on the purpose, smoothing layer for surface smoothing, hard coat layer for imparting scratch resistance, ultraviolet absorbing layer for enhancing light resistance, surface roughening layer for improving film transportability, etc. Various known functional layers can be provided.

-Transparent conductive layer-
A transparent conductive layer can be installed in the optical film of the present invention. As the transparent conductive layer, a known metal film, metal oxide film, or the like can be applied. Among these, a metal oxide film is preferable from the viewpoint of transparency, conductivity, and mechanical characteristics. Examples of the metal oxide film include indium oxide, cadmium oxide and tin oxide to which tin, tellurium, cadmium, molybdenum, tungsten, fluorine, zinc, germanium and the like are added as impurities; zinc oxide and titanium oxide to which aluminum is added as impurities A metal oxide film such as; 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 can be preferably used.
The transparent conductive layer can be formed by any method as long as it can form a target thin film. As the film forming method, for example, a vapor deposition method for forming a film by depositing a material from a gas phase such as a sputtering method, a vacuum deposition method, an ion plating method, and a plasma CVD method is suitable. Films can be formed by the methods described in Japanese Patent Nos. 3400324, 2002-322561, and 2002-361774.
Among these, the sputtering method is preferable from the viewpoint that particularly excellent conductivity and transparency can be obtained.

A preferable degree of vacuum of such a sputtering method, a vacuum deposition method, an ion plating method, and a plasma CVD method is 0.133 mPa to 6.65 Pa, more preferably 0.665 mPa to 1.33 Pa. Before providing such a 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 to 200 degreeC during providing the transparent conductive layer.
The thickness of the transparent conductive layer thus obtained is preferably 20 nm to 500 nm, more preferably 50 nm to 300 nm.
The surface electrical resistance of the transparent conductive layer thus obtained, measured at 25 ° C. and 60% relative humidity, is preferably 0.1Ω / □ to 200Ω / □, more preferably 0.1Ω / □ to 100Ω / □. □, more preferably 0.5Ω / □ to 60Ω / □. Further, the light transmittance is 80% or more, more preferably 83% or more, and still more preferably 85% or more.

-Gas barrier layer-
The optical film of the present invention is preferably provided with a gas barrier layer in order to suppress gas permeability. Preferred gas barrier layers include, for example, metal oxides composed mainly of one or more metals selected from the group consisting of silicon, aluminum, magnesium, zinc, zirconium, titanium, yttrium, and tantalum, silicon, aluminum, boron And a layer made of a metal nitride or a mixture 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. Metal oxide is good. These inorganic gas barrier layers can be produced by vapor deposition such as sputtering, vacuum deposition, ion plating, plasma CVD, or the like, in which a material is deposited in the vapor phase to form a film. Of these, the sputtering method is preferred from the viewpoint that particularly excellent gas barrier properties can be obtained. Further, the temperature may be raised to 50 ° C. to 200 ° C. while the gas barrier layer is provided.

The thickness of the inorganic gas barrier layer thus obtained is preferably 10 nm to 300 nm, more preferably 30 nm to 200 nm.
Such a gas barrier layer may be provided on the same side as the transparent conductive layer or on the opposite side, but it is more preferable to provide the gas barrier layer on the opposite side of the side where the transparent conductive layer is provided.
The barrier property of the gas barrier film thus obtained is preferably such that the water vapor permeability measured at 40 ° C. and a relative humidity of 90% is 5 g / m ² · day or less, more preferably 1 g / m ² · day or less. More preferably, it is 0.5 g / m ² · day or less. The oxygen permeability measured at 40 ° C. and 90% relative humidity is preferably 1 ml / m ² · day or less, more preferably 0.7 ml / m ² · day or less, and even more preferably 0.5 ml. / M ² · day or less.

In the optical film of the present invention, it is particularly desirable to provide a defect compensation layer adjacent to the gas barrier layer for the purpose of improving barrier properties.
As the defect compensation layer, (1) a method using an inorganic oxide layer produced by using a sol-gel method as described in US Pat. No. 6,171,663 and JP-A-2003-94572, (2) US As described in Japanese Patent No. 6413645, a method using an organic layer, a method of vapor deposition under vacuum and curing with ultraviolet rays or an electron beam, or a coating, followed by curing with heating, electron beam, ultraviolet rays, etc. It can produce.
When the defect compensation layer is produced by a coating method, various conventionally used coating methods such as spray coating, spin coating, and bar coating can be used.

  The optical film of the present invention can be applied to various uses that can utilize the optical characteristics thereof. In particular, the present invention can be preferably applied to an image display device as described below. The optical film of the present invention can also be used for applications such as solar cells and touch panels. The touch panel can be applied to those described in JP-A-5-127822, JP-A-2002-48913, and the like.

<Image display device>
The image display device of the present invention includes the optical film of the present invention. In particular, the optical film of the present invention can be used in an image display device after providing various functional layers as necessary. Here, it does not specifically limit as an image display apparatus, A conventionally well-known thing can be used. Moreover, the flat panel display excellent in display quality can be produced using the optical film of this invention. Flat panel displays include liquid crystals, plasma displays, electroluminescence (EL), fluorescent display tubes, light emitting diodes, etc. In addition to these, they should be used as substrates instead of display-type glass substrates that have conventionally used glass substrates. Can do.

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

  When the optical film of the present invention is used for a liquid crystal display or the like, the film is preferably made of an amorphous polymer in order to achieve optical uniformity. In addition, when used for such applications, it is preferable that the birefringence of the optical film of the present invention is small, in particular, the in-plane retardation (Re) is preferably 50 nm or less, more preferably 30 nm or less, even more preferably. Is 15 nm or less. In order to obtain an optical film having a small birefringence by using only the polymer, it is possible to appropriately adjust the solvent and the drying conditions during solution casting. Moreover, it can also extend | stretch and adjust as needed. Furthermore, for the purpose of controlling retardation (Re) and its wavelength dispersion, resins having different intrinsic birefringence signs can be combined, or resins having large (or small) wavelength dispersion can be combined. In addition, the optical film of the present invention can be suitably used for the purpose of controlling retardation (Re) and improving gas permeability and mechanical properties, etc. Further, phase difference compensation can be performed by using a known retardation plate in combination.

  A reflective liquid crystal display device is generally composed 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. . Of these, the optical film of the present invention may be used as a λ / 4 plate or a protective film for a polarizing film by adjusting optical properties, but is preferably used as a substrate (upper and lower substrates) from the viewpoint of heat resistance. It is also preferable to use it as a transparent electrode and an upper substrate with an alignment film from the viewpoint of transparency. Moreover, a gas barrier layer, TFT, etc. can also be provided as needed. In the case of color display, it is preferable to further provide 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 Generally, it is made of a polarizing film. Of these, the optical film of the present invention may be used as a λ / 4 plate or a protective film for a polarizing film by adjusting optical properties, but is preferably used as a substrate (upper and lower substrates) from the viewpoint of heat resistance, and transparent electrodes It is preferable to use it as a substrate with an alignment film. Moreover, a gas barrier layer, TFT, etc. can also be provided as needed. 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 types of liquid crystal layer (liquid crystal cell) include TN (Twisted Nematic), IPS (In-P1ane Switching), FLC (Ferroelectric Liquid Crysta1), AFLC (Anti-ferroelectric Liquid Crystal), OCB (Optica1ly Compensatory Bend), STN (Supper Various display modes such as Twisted Nematic (VA), 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 optical film of the present invention can be effectively used in a liquid crystal display device in any display mode. In addition, the liquid crystal display device can be effectively used in any of transmissive, reflective, and transflective liquid crystal display devices.

  These liquid crystal display devices are disclosed in JP-A-2-176625, JP-B-7-69536, MVA (SID97, Digest of tech. Papers (Preliminary Collection) 28 (1997) 845), SID99, Digest of tech. Papers (Proceedings) 30 (1999) 206, JP-A-11-258605, SURVAIVAL (Monthly Display, Vol. 6, No. 3 (1999) 14), PVA (Asia Display 98, Proc. Of the-18th- Inter. Display res. Conf. (Preliminary Collection) (1998) 383), Para-A (LCD / PDP Iternational`99), DDVA (SID98, Digest of tech. Papers (Preliminary Collection) 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 10 123478 JP, International Publication W098 / forty-eight thousand three hundred and twenty JP, are described in Patent No. 3,022,477 Publication and WO WO00 / sixty-five thousand three hundred and eighty-four No. or the like.

As described above, the optical film of the present invention is provided with a gas barrier layer and a TFT as necessary, and can be used as a substrate with a transparent electrode for organic EL display applications.
As a specific layer structure as the organic EL display element, 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 Examples include injection layer / transparent cathode.

The organic EL device that can use the optical film of the present invention can emit light by applying a DC voltage or a DC current between the anode and the cathode. The DC voltage is usually 2 to 40 volts, and may include an AC component as necessary.
The driving of these light emitting elements is disclosed in JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234665, and JP-A-8-241047. U.S. Pat. Nos. 5,828,429, 6,023,308, and No. 2,784,615 can be used.

  The features of the present invention will be described more specifically with reference to the following examples. The following materials, amounts used, ratios, processing details, processing procedures, and the like 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) Synthesis of Polymer for Optical Film Synthesis of Exemplified Compound P-13 Exemplified Compound P-13 was synthesized according to the following scheme.

Ｍ−１０１を２３５．５９ｇ（６４６．８ｍｍｏｌ）、テトラブチルアンモニウムクロライドを９．１７１ｇ（３３ｍｍｏｌ）、ジクロロメタンを２８０５ｍｌ、および水を２４７５ｍｌ、攪拌装置を備えた反応容器中に投入し、窒素気流下で、水浴中３００ｒｐｍで撹拌を行った。３０分後、２，６−ナフタレンジカルボン酸クロライドを１６７．０３ｇ（６６０ｍｍｏｌ）粉体のまま投入し、３３０ｍｌのジクロロメタンで洗い流した。１０分後、ｐ−ｔｅｒｔ−ブチルフェノール３．９６６ｇ（２６．４ｍｍｏｌ）を２規定水酸化ナトリウム水溶液６９３ｍｌに溶解し１３２ｍｌの水で希釈した液を１時間かけて滴下装置を用いて滴下し、終了後１６５ｍｌの水で洗浄した。その後３時間撹拌を継続した後、ジクロロメタン１Ｌを添加し、有機相を分離した。さらに１２規定塩酸水６．６ｍｌを水２．５Ｌで希釈した溶液を添加し有機相を洗浄した。さらに水２．５Ｌで２回洗浄を行った後、分離した有機相にジクロロメタン１Ｌを添加し、希釈した後、激しく撹拌した２５Ｌのメタノール中に１時間かけて投入した。メタノール中、得られた白色沈殿を濾取し、４０℃、１２ｈ加熱乾燥後、７０℃、３時間、減圧下で乾燥し、例示化合物Ｐ−１３を３０７．２ｇ得た。
得られた例示化合物Ｐ−１３の分子量をＧＰＣ（ＴＨＦ溶媒）で測定した結果、重量平均分子量が６１０００であった。また、得られたポリマーのガラス転位温度は３０２℃であった。

235.59 g (646.8 mmol) of M-101, 9.171 g (33 mmol) of tetrabutylammonium chloride, 2805 ml of dichloromethane, and 2475 ml of water were put into a reaction vessel equipped with a stirrer, under a nitrogen stream. The mixture was stirred at 300 rpm in a water bath. After 30 minutes, 2,6-naphthalenedicarboxylic acid chloride was added in the form of 167.03 g (660 mmol) powder and washed with 330 ml of dichloromethane. Ten minutes later, a solution obtained by dissolving 3.966 g (26.4 mmol) of p-tert-butylphenol in 693 ml of 2N aqueous sodium hydroxide solution and diluting with 132 ml of water was added dropwise over 1 hour using a dropping device. Washed with 165 ml water. Thereafter, stirring was continued for 3 hours, and then 1 L of dichloromethane was added to separate the organic phase. Further, a solution obtained by diluting 6.6 ml of 12N hydrochloric acid with 2.5 L of water was added to wash the organic phase. After further washing with 2.5 L of water twice, 1 L of dichloromethane was added to the separated organic phase, diluted, and then poured into 25 L of methanol that was vigorously stirred over 1 hour. The resulting white precipitate in methanol was collected by filtration, dried by heating at 40 ° C. for 12 hours, and then dried at 70 ° C. for 3 hours under reduced pressure to obtain 307.2 g of Exemplified Compound P-13.
As a result of measuring the molecular weight of the obtained exemplary compound P-13 with GPC (THF solvent), the weight average molecular weight was 61,000. Moreover, the glass transition temperature of the obtained polymer was 302 degreeC.

Synthesis of Exemplary Compound P-30 25.3 g of BPFL (trade name; manufactured by JFE Chemical Co., Ltd.), 9.17 g of tetrabutylammonium chloride, 222 ml of dichloromethane, 69.3 ml of 2 mol / L sodium hydroxide aqueous solution, and 38 ml of water was put into a reaction vessel equipped with a stirrer, and stirred at 300 rpm in a water bath under a nitrogen stream. After 30 minutes, 6.7 g of isophthalic acid chloride and 6.7 g of terephthalic acid chloride dissolved in 74 ml of dichloromethane were added. Thereafter, stirring was continued for 3 hours, and then 100 mL of dichloromethane was added to separate the organic phase. Further, a solution obtained by diluting 0.66 ml of 12 mol / L hydrochloric acid water with 250 ml of water was added to wash the organic layer. After further washing twice with 250 ml of water, 100 ml of dichloromethane was added to the separated organic layer for dilution. The diluted solution was then poured into 2.5 liters of vigorously stirred methanol over 1 hour. The resulting white precipitate in methanol was collected by filtration, heated and dried at 40 ° C. for 12 hours, and then dried at 70 ° C. for 3 hours under reduced pressure to obtain 28 g of Exemplified Compound P-30.
As a result of measuring the molecular weight of the obtained exemplary compound P-30 with GPC (THF solvent), the weight average molecular weight was 50,000. The glass transition point measured by DSC was 320 ° C.

Synthesis of Exemplified Compound P-43 A dimethylacetamide solution of Exemplified Compound P-43 was obtained according to the method described in JP-A-62-230823 and Example 1. The glass transition temperature of the obtained polymer was 320 ° C.

Synthesis of Exemplified Compound P-44 An N-methyl-2-pyrrolidone solution of P-44 was obtained according to the method described in Examples of JP-A-2003-168800. The obtained polymer solution was cast on a glass substrate and dried with hot air at 200 ° C. for 1 hour, and the glass transition temperature of the film was 315 ° C.

[Example 1]
<Preparation of Optical Film Samples 101-110, 116, 117>
The exemplified compound P-13 or the exemplified compound P-30 (polymer) was dissolved at a concentration such that the solution viscosity after being dissolved in dichloromethane was in the range of 500 to 1500 mPa · s. Furthermore, the deterioration inhibitors described in Table 1 below were added to this solution and dissolved. The solution was filtered through a 5 μm filter and cast on a glass substrate using a doctor blade. After casting, the film was heat-dried at room temperature for 2 hours, at 80 ° C. for 2 hours, and at 100 ° C. for 4 hours, and the film was peeled off from the glass substrate to prepare optical film samples (samples 101 to 110). An optical film sample (Comparative Samples 116 and 117) to which no deterioration inhibitor was added was prepared in the same manner.

<Preparation of optical film samples 111-113, 118>
To the dimethylacetamide solution of Exemplified Compound P-43 obtained in Synthesis Example 3 above, the degradation inhibitor described in Table 1 below was added and dissolved. The solution was filtered through a 5 μm filter and cast on a glass substrate using a doctor blade. After casting, it was heat-dried at 140 ° C. for 1 hour under a nitrogen atmosphere, and further heat-dried at 200 ° C. for 2 hours under vacuum. After drying, the film was peeled off from the glass substrate to prepare optical film samples (samples 111 to 113). A sample (Comparative Sample 118) to which no deterioration inhibitor was added was prepared in the same manner.

<Preparation of optical film samples 114, 115, 119>
The deterioration inhibitors listed in Table 1 below were added to the N-methyl-2-pyrrolidone solution of P-44 obtained in Synthesis Example 4 and dissolved. This solution was cast on a glass substrate using a doctor blade. After casting, the film is dried at 100 ° C. for 1 hour in a nitrogen atmosphere, and after drying, the film is peeled off from the glass substrate, fixed to a stainless steel fixing frame, and dried at 200 ° C. for 1 hour in a nitrogen atmosphere to obtain an optical film sample (114 115). A sample (Comparative Sample 119) to which no deterioration inhibitor was added was prepared.

  Table 1 shows the components of the optical film sample produced. In the table (), the amount of each deterioration inhibitor added to each constituent polymer is shown as a mass% value.

  For each optical film in Table 1, 1) transmittance immediately after film formation at 420 nm, 2) transmittance after heating at 280 ° C. for 10 hours under nitrogen (transmittance after heating), and 3) by a sunshine carbon arc lamp The transmittance after exposure (transmittance after light irradiation) under conditions of relative humidity of 60% and 90 hours was measured using a sunshine weather meter (S? 80, manufactured by Suga Test Instruments Co., Ltd.). The results are shown in Table 2 below.

  From Table 2, it can be seen that Samples 101 to 115, which are the optical films of the present invention, are less colored by heating and light irradiation than the optical film samples 116 to 119 of Comparative Examples.

<Preparation of organic EL element samples 201-219>
(Installation of gas barrier layer)
On both surfaces of the optical film samples 101 to 119 produced as described above, oxygen was introduced under a vacuum of 500 Pa using Si as a target under a vacuum of 500 Pa, under an argon gas atmosphere, and sputtered at an output of 5 kW with a pressure of 0.1 Pa. . The film thickness of the obtained gas barrier layer was 60 nm. The optical film sample on which the gas barrier layer is formed 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 at 40 ° C. and a relative humidity of 90%. ² · day or less.

(Installation of transparent conductive layer)
While heating the optical film sample provided with the gas barrier layer to 100 ° C, ITO (In ₂ O ₃ 95% by mass, SnO ₂ 5% by mass) was used as a target by DC magnetron sputtering under argon of 0.665 Pa. A transparent conductive layer made of an ITO film having an output of 5 kW and a thickness of 140 nm was provided on one side in a gas atmosphere. The surface electrical resistance at 25 ° C. and 60% relative humidity of the optical film sample provided with the transparent conductive layer was 30Ω / □.

(Heat treatment of optical film with transparent conductive layer)
The optical film sample provided with the transparent conductive layer obtained above was subjected to a heat treatment at 270 ° C. for 10 hours assuming TFT installation.

(Production of organic EL element)
From the transparent electrode layer of the optical film sample on which the transparent conductive layer subjected to the heat treatment was installed, an aluminum lead wire was 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. A hole-transporting organic thin film layer having a thickness of 100 nm was formed. This was designated as substrate X.
On the other hand, using a spin coater, a coating solution for a light-emitting organic thin film layer having the following composition is formed on one surface of a temporary support made of polyethersulfone having a thickness of 188 μm (Sumilite FS-1300, manufactured by Sumitomo Bakelite Co., Ltd.). By coating and drying at room temperature, a light-emitting organic thin film layer having a thickness of 13 nm was formed on the temporary support. This was designated as transfer material Y.

[Composition of coating solution for light-emitting organic thin film]
Polyvinylcarbazole: 40 parts by mass (Mw = 63000, manufactured by Aldrich)
・ Tris (2-phenylpyridine) iridium complex: 1 part by mass (orthometalated complex)
・ Dichloroethane: 3200 parts by mass

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

In addition, a patterned vapor deposition mask (a mask with a light emitting area of 5 mm × 5 mm) is installed on one side of a polyimide film (UPILEX-50S, manufactured by Ube Industries, Ltd.) having a thickness of 50 μm cut into 25 mm square, Al was evaporated in a reduced pressure atmosphere of about 0.1 mPa to form an electrode having a 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, whereby an electron having a thickness of 15 nm is obtained. A transportable organic thin film layer was formed. This was designated as substrate Z.

[Composition of coating liquid for electron transporting organic thin film layer]
Polyvinyl butyral 2000L: 10 parts by mass (Mw = 2000, manufactured by Denki Kagaku Kogyo Co., Ltd.)
1-butanol: 3500 parts by mass Electron transporting compound having the following structure: 20 parts by mass

  Using substrate XY and substrate Z, the electrodes are stacked so that the electrodes face each other with the light-emitting organic thin film layer sandwiched between them, and heated and pressed at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers. Then, organic EL element samples 201 to 219 were obtained by bonding.

  A DC voltage was applied to the obtained organic EL element samples 201 to 219 using a source measure unit 2400 type (manufactured by Toyo Technica Co., Ltd.). Although it was confirmed that all emitted light, in Comparative Samples 216 to 219, the base film X was markedly colored in the EL element manufacturing step, and an EL display with high color purity was not obtained. On the other hand, in the samples 201 to 215 of the present invention, it was confirmed that there was almost no coloring of the film in the EL element manufacturing process, and high-quality EL display was obtained.

  From the said Example, it became clear that the optical film of this invention is excellent in heat resistance and transparency. Further, it has been clarified that a gas barrier layer and a transparent conductive layer can be laminated, and even if a heat treatment assuming a TFT process is performed, coloring and deformation do not occur and function as a substrate film for an organic EL element.

  The optical film of the present invention has high heat resistance, transparency, and little deterioration due to heat and light. This optical film is suitable for various functional layer installation processes such as a TFT installation process that requires a high temperature process, and is suitable as a substrate for plastic displays such as organic EL.

Claims (10)

  An optical film comprising a polymer having a glass transition temperature of 250 ° C. or higher, (1) a carbon radical scavenger, (2) a primary antioxidant having a hydrogen radical donating ability for peroxy radicals, and (3) peroxide An optical film comprising at least one kind of deterioration inhibitor selected from secondary antioxidants having a reducing action on water.   The optical film according to claim 1, wherein the deterioration preventing agent contains at least the carbon radical scavenger. The optical film according to claim 1 or 2, wherein the carbon radical scavenger is a compound represented by the following general formula (1).

[In General Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ² and R ³ each independently represents an alkyl group having 1 to 8 carbon atoms. ]   4. The method according to claim 1, wherein at least the primary antioxidant is contained as the deterioration inhibitor, and the primary antioxidant is a phenol-based antioxidant or an amine-based antioxidant. 2. The optical film according to item 1.   5. The deterioration inhibitor, which contains at least the secondary antioxidant, and the secondary antioxidant is a sulfur-based antioxidant or a phosphorus-based antioxidant. The optical film of any one of these.   The optical film according to any one of claims 1 to 5, wherein the polymer having a glass transition temperature of 250 ° C or higher is polyarylate, polyamide, or polyimide. The polymer having a glass transition temperature of 250 ° C or higher has a spiro structure represented by the following general formula (2) or a cardo structure represented by the following general formula (3). 2. An optical film according to item 1.

[In general formula (2), ring α represents a monocyclic or polycyclic ring, and the two rings are connected by a spiro bond. The two rings α may be the same or different. ]
General formula (3)

[In general formula (3), ring β and ring γ represent a monocyclic or polycyclic ring. The two rings γ may be the same or different, and are connected at one quaternary carbon on the ring β. ]   An optical film comprising a gas barrier layer on the optical film according to claim 1.   An optical film comprising a transparent conductive layer on the optical film according to claim 1.   An image display device comprising the optical film according to claim 1.