TW202147660A - Optical film, polarizing plate, and organic electroluminescence image display device - Google Patents

Abstract

The present invention addresses the problem of providing: an optical film that, when applied to an image display device, prevents light leakage despite having high transparency, and also has excellent light resistance and durability under harsh environmental conditions; and a polarizing plate and organic electroluminescence image display device that are provided with the optical film. The optical film according to the present invention contains a thermoplastic resin, and is characterized by containing a compound having a structure represented by general formula (1). (In the formula, Z represents a heteroaryl group having two or more heteroatoms, and is optionally substituted.).

Description

Optical film, polarizing plate and organic electroluminescence image display device

The present invention relates to an optical film, a polarizing plate and an organic electroluminescence image display device, and more specifically, when used in an image display device, it not only has high transparency, prevents light leakage, but also has high transparency under strict environmental conditions. Optical films with excellent light resistance and durability.

In the organic electroluminescence (hereinafter also referred to as "organic EL") image display device, the reflection of light outside the metal plate inside is remarkable, and a combination of a λ/4 retardation film and a polarized light reflection prevention film is used. When a cyclic olefin resin (hereinafter also referred to as "COP") is used as the material of the retardation film, reflection leakage occurs at a specific wavelength due to the influence of the wavelength dispersibility. Here, in order to suppress reflection leakage, a layer containing a dye that absorbs light of a specific wavelength (hereinafter also referred to as a "light-absorbing layer of specific wavelength") must be installed in the display. The specific wavelength light absorbing layer only needs to be in the display, and can also be arranged at any position, and can also be arranged as the λ/4 retardation film.

However, when a dye is directly added to a resin to produce a retardation film, there is an interaction with the resin, which promotes photodegradation of the dye.

For example, Patent Document 1 discloses a method of adding a dye that absorbs light having a wavelength of around 400 nm to an adhesive layer in order to protect the organic EL element, and Patent Document 2 discloses that the brightness and visibility of an organic EL image display device are to be improved. A method of adding a dye that absorbs light selected from around 470 nm and around 600 nm to an adhesive, and the like.

In these techniques, pigments or UV absorbers are mainly added to the adhesive, but since the adhesive layer is thin, it is difficult to uniformly add the compound that is intended to express the function.

Moreover, it describes in patent document 3, in order to block ultraviolet rays and a part of visible rays from the outside, a plurality of dye compounds can be incorporated in any layer of the functional layer. In addition, it is described in Patent Document 4 that an indole compound is contained in a tackifier, etc., or a specific structure dye compound having a cyano group and an ester group is added to the resin or functional layer in Patent Document 5, but all dye compounds are described. There is also a problem of insufficient light resistance. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-165941 [Patent Document 2] Japanese Patent No. 5599740 [Patent Document 3] Japanese Patent Laid-Open No. 2017-198991 [Patent Document 4] International Publication No. 2017/15996 [Patent Document 5] Japanese Patent Laid-Open No. 2018-200463

[Problems solved by the invention]

The present invention has been made in view of the above-mentioned problems and situations, and the problem to be solved is to provide an image display device that not only has high transparency and prevents light leakage, but also has excellent light resistance and durability under severe environmental conditions. An optical film, a polarizing plate and an organic electroluminescence image display device having the same. [Means to solve the problem]

In order to solve the above-mentioned problems, the present inventors have examined the causes of the above-mentioned problems, etc., and found that an optical film containing a thermoplastic resin, by containing a compound of a specific structure, can be obtained when it is applied to an image display device, and not only has high transparency, but also has high transparency. Anti-leakage optical film with excellent light resistance and durability under severe environmental conditions.

That is, the said subject concerning this invention is solved by the following means.

1. An optical film containing a thermoplastic resin, characterized by being an optical film containing a compound having a structure represented by the following general formula (1).

(In the formula, Z represents a heteroaryl group having two or more heteroatoms, and may have a substituent.)

2. The optical film according to item 1, wherein Z is any one of the groups represented by the following structural formulae.

(The group represented by the above structural formula may further have a substituent. In addition, R represents a substituent.)

3. Further, the optical film according to the item 2, wherein Z is any one of the groups represented by the following structural formulas.

(The group represented by the above structural formula may further have a substituent. In addition, R represents a substituent.)

4. Any one of items 1 to 3 characterized in that the energy level of the highest occupied molecular orbital (Energy level of the highest occupied molecular orbital) of the compound having the structure represented by the general formula (1) is -5.85 eV or less An optical film as described.

5. The optical film according to any one of Items 1 to 4, wherein the thermoplastic resin is characterized by being a cyclic olefin-based resin or an acrylic resin.

6. The aforementioned cyclic olefin-based resin is the optical film according to item 5, which is characterized by having a polar group.

7. The compound described in any one of Items 1 to 6, characterized in that the compound having the structure represented by the general formula (1) is contained within a range of 0.01 to 20 mass % with respect to the thermoplastic resin optical film.

8. The optical film according to any one of Items 1 to 7, characterized by further having a functional layer.

9. The functional layer is the optical film according to item 8, which is characterized by containing the compound having the structure represented by the general formula (1).

10. The aforementioned optical film is the optical film according to any one of Items 1 to 9, which is characterized by being a λ/4 retardation film.

11. A polarizing plate characterized by having the optical film according to any one of Items 1 to 10.

12. An organic electroluminescence image display device characterized by comprising the optical film according to any one of Items 1 to 10 or the polarizing plate according to Item 11. [Effect of invention]

By means of the above-mentioned means of the present invention, it is possible to provide an optical film suitable for an image display device, not only having high transparency and preventing light leakage, but also having excellent light resistance and durability under severe environmental conditions, and a polarizing plate having the same. And organic electroluminescence image display device.

Although the expression mechanism or the action mechanism of the effect of the present invention is not yet clear, it is presumed as follows.

As the λ/4 retardation film, a cyclic olefin-based resin film can be used from the viewpoints of low hygroscopicity and good dimensional stability.

However, since the cyclic olefin resin film exhibits wavelength dispersion characteristics of a flat plate, it is used, for example, as a λ/4 retardation film for a circular polarizer in an organic electroluminescence (hereinafter also referred to as "organic EL") image display device. During use, reflected light tends to leak in a specific wavelength region (region on the short wavelength side). If the leakage of the reflected light is conspicuous, the color of the reflected light tends to decrease.

In order to suppress the reduction of the color by reflected light as described above, the present inventors examined adding a dye compound that absorbs light in this wavelength region to a film. In order for an organic EL image display device to be used in a high-temperature and high-humidity environment, it is required that the deterioration of the organic EL element by external light can be suppressed. Moreover, since the dye compound is also deteriorated by incident light, the light resistance of the compound itself is also required.

Here, in order to solve such a problem, it is considered that if a dye compound of a specific structure is used, light deterioration can be suppressed, and a λ/4 retardation film with improved overall durability can be produced by further combining with a specific thermoplastic resin.

As a result of the review, it was found that if the pigment compound with the above-mentioned specific structure has a structure with a dicyano group, the cyano group will reduce the energy level of the highest occupied molecular orbital (HOMO; Highest occupied molecular orbital), which can reduce the oxidation potential. Therefore, photo-oxidation can be inhibited, and thus the light resistance of the dye compound can be improved. Then, it was found that if the energy level of the above-mentioned highest occupied molecular orbital (HOMO) of the pigment compound and the energy level of the thermoplastic resin do not easily interact with each other, the deterioration of light resistance or durability can be further suppressed.

[Type of carrying out the invention]

The optical film of the present invention is an optical film containing a thermoplastic resin, and is characterized by containing the compound having the structure represented by the general formula (1). This feature is a technical feature common to or corresponding to the following embodiments.

As an embodiment of the present invention, from the viewpoint of the effect of the present invention, if Z in the structure represented by the aforementioned general formula (1) is any one of the structures represented by claim 2 or claim 3, it can be It is preferable from the viewpoint of obtaining an optical film with an excellent balance of light leakage prevention and light resistance.

In addition, it is preferable that the energy level of the highest occupied molecular orbital of the compound having the structure represented by the general formula (1) is -5.85 eV or less, from the viewpoint of obtaining an optical film with excellent durability.

In addition, when the thermoplastic resin is a cyclic olefin resin or an acrylic resin, it is preferable from the viewpoint of obtaining an optical film excellent in light leakage prevention and light resistance and durability. Among them, because the aforementioned cyclic olefin resin has a polar group, it is difficult for the energy level of the highest occupied molecular orbital of the dye to interact with the energy level of the resin, and the deterioration of light resistance or durability can be suppressed.

In the present invention, the compound having the structure represented by the general formula (1) is preferably contained in the range of 0.01 to 20 mass % with respect to the thermoplastic resin. When it is less than 0.01 mass %, the effect of the present invention is small, and when it exceeds 20 mass %, precipitation (also referred to as external leakage) from the thin film is likely to occur under high temperature and high humidity.

In addition, the optical film preferably has a functional layer, and the functional layer preferably contains the compound having the structure represented by the general formula (1). Examples of the functional layer include a hard coat layer, an adhesive layer, a smoothing layer, a light scattering layer, and the like, but the hard coat layer is preferable from the viewpoint of imparting scratch resistance to the optical film.

The optical film of the present invention is preferably a λ/4 retardation film, and a circular polarizing plate for preventing reflection can be provided by having a polarizing plate.

Furthermore, the organic electroluminescence image display device of the present invention is characterized by having the optical film or polarizing plate of the present invention.

Hereinafter, the present invention, the constituent elements, and the form and aspect of the present invention will be described in detail. In addition, in this case, "~" means that the numerical value described before and after it is included as a lower limit value and an upper limit value.

≪Outline of the optical film of the present invention≫ The optical film of the present invention is an optical film containing a thermoplastic resin, and is characterized by containing a compound having a structure represented by the following general formula (1).

According to the present invention, by using the compound having the structure represented by the general formula (1), the energy level of the highest occupied molecular orbital (HOMO) can be lowered. By reducing the energy level of HOMO, the oxidation potential can be lowered and photo-oxidation can be suppressed. In other words, the effect of improving the light resistance of the dye compound can be achieved.

The calculation of the HOMO by the molecular orbital calculation of the compound having the structure represented by the general formula (1) is, as the calculation method, B3LYP can be used by the functional, and 6-31G(d) can be used by the basis function. The molecular orbital calculation of ) is calculated by software, and the software is not particularly limited, and any one can be used to obtain it in the same way.

In the present invention, Gaussian09 (Revision C.01, M.J. Frisch, et al, Gaussian, Inc., 2010.) manufactured by Gaussian Corporation of the United States was used as the software for molecular orbital calculation.

In addition, the optical film of the present invention is preferably transparent, and the so-called "transparent" is based on JIS K 7375: 2008 "Plastic-Method for Determining Total Light Transmittance and Total Light Reflectance", using a spectrophotometer (such as Hitachi U-3300 manufactured by High-Tech Science) can be measured, and the light transmittance is 80% or more.

The constituent elements of the present invention will be described in detail below.

[1] A compound having a structure represented by the general formula (1) The present invention relates to a compound having a structure represented by the general formula (1) (hereinafter also referred to as a "dye compound".) having the following structure.

(In the formula, Z represents a heteroaryl group having two or more heteroatoms, and may have a substituent.)

In the formula, Z further represents any group shown in the following structural formula, and may further have a substituent. In the following structural formula, R represents a substituent.

Among them, it is also preferable that the aforementioned Z is any group represented by the following structural formula, from the viewpoint of expressing the effects of the present invention. In the following structural formula, R represents a substituent.

The above R represents a substituent, for example, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), alkyl groups (methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, 2-ethylhexyl, etc.), cycloalkyl (cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl, etc.), alkenyl (vinyl, allyl, etc.), cycloalkyl (cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl, etc.) Alkenyl (2-cyclopenten-1-yl, 2-cyclohexen-1-yl, etc.), alkynyl (ethynyl, propynyl, etc.), aromatic hydrocarbon ring (phenyl, p-tolyl, etc.) , naphthyl, etc.), aromatic heterocyclic groups (2-pyrrolyl, 2-furyl, 2-thienyl, pyrrolyl, imidazolyl, oxazolyl, thiazolyl, benzimidazolyl, benzoxazolyl , 2-benzothiazolyl, pyrazolone, pyridyl, pyridone, 2-pyrimidinyl, triazinyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4- Triazolyl, oxazolyl, isoxazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, thiazolyl, isothiazolyl, 1,2,4-thiazolyl azolyl, 1,3,4-thiadiazolyl, etc.), cyano, hydroxyl, nitro, carboxyl, alkoxy (methoxy, ethoxy, isopropoxy, tert-butoxy, n -Octyloxy, 2-methoxyethoxy, etc.), Aryloxy (phenoxy, 2-methylphenoxy, 4-tert-butylphenoxy, 3-nitrophenoxy base, 2-tetradecylaminophenoxy, etc.), acyloxy (formyloxy, acetyloxy, neopentyloxy, stearyloxy, benzyloxy , p-methoxyphenylcarbonyloxy, etc.), amine (amine, methylamine, dimethylamine, aniline, N-methyl-anilino, diphenylamine, etc.), Acylamino (methylamino, acetamido, neopentylamino, laurylamino, benzylamino, etc.), alkyl and arylsulfonamido (methyl Sulfonylamino, butylsulfonamido, phenylsulfonamido, 2,3,5-trichlorophenylsulfonamido, p-methylphenylsulfonamido, etc. ), mercapto, alkylthio (methylthio, ethylthio, n-hexadecylthio, etc.), arylthio (phenylthio, p-chlorophenylthio, m- Methoxyphenylthio, etc.), aminosulfonyl (N-ethylaminosulfonyl, N-(3-dodecyloxypropyl)aminosulfonyl, N,N- Dimethylaminosulfonyl, N-acetamidosulfonyl, N-benzylaminosulfonyl, N-(N'-phenylaminocarbamoyl)aminosulfonyl etc.), sulfonic acid group, acyl group (acetyl group, neopentyl benzyl group, etc.), amino carboxyl group (amino carboxyl group, N-methylamino carboxyl group, N,N - Each group such as dimethylaminocarbamoyl, N,N-di-n-octylaminocarbamoyl, N-(methylsulfonamido)carbamoyl, etc.).

Although the dye compound which has the structure represented by general formula (1) concerning this invention is illustrated below, this invention is not limited to these.

Although the molecular weight of the above-mentioned pigment compound is not particularly limited, in order to easily enter between the molecules of the cyclic olefin resin or the acrylic resin, it is preferable not to be too large, for example, 100 to 1000 is preferable. The molecular weight of the dye compound can be calculated from the formula of the chemical structural formula, for example, by a specific chemical structure such as an NMR (Nuclear Magnetic Resonance: Nuclear Magnetic Resonance) apparatus.

The maximum absorption wavelength of the pigment compound is preferably in the range of 370 to 460 nm, and preferably in the range of 400 to 440 nm. When the maximum absorption wavelength of the dye compound is within the above range, the optical film easily absorbs light in this wavelength region appropriately. Therefore, for example, when the optical film is used as a λ/4 retardation film in an organic EL image display device, it can be used. A further layer suppresses light leakage of reflected light in this wavelength region. The maximum absorption wavelength of the dye compound can be obtained by measuring the absorption spectrum of the dye compound in dichloromethane using an ultraviolet-visible spectrophotometer UV-2450 manufactured by Shimadzu Corporation.

The pigment compound can be obtained by synthesis, and a commercial product can also be used. For example, the synthesis of the exemplary dye compound 12 can be synthesized by the following scheme.

1.5 g of compound (12-1) and 0.697 g of malononitrile were measured in a 100 mL three-headed piston, and 40 mL of toluene was added and dissolved. Next, after adding 0.817 g of morpholine dropwise, the temperature was raised and the mixture was heated and refluxed for 4 hours. After the completion of the reaction, the solvent was removed under reduced pressure, 10 mL of methanol was added, and the mixture was stirred in a suspended state. The precipitate was filtered and dried to obtain 1.89 g (yield 96%) of powder of the exemplified pigment compound 12. The structure can be confirmed by NMR.

The content of the dye compound is preferably in the range of 0.01 to 20 mass % with respect to the cyclic olefin resin. When the content of the dye compound is 0.01 mass % or more, light in a specific wavelength region is appropriately absorbed, for example, an effect of improving light resistance can be obtained while suppressing light leakage of reflected light in an organic EL image display device. When the content of the dye compound is 20 mass % or less, not only does external leakage not easily occur, but also the decrease in brightness can be suppressed in order to prevent the light absorption in the specific wavelength region of the optical film from being too high. From the same viewpoint, the content of the dye compound is preferably in the range of 0.015 to 10 mass % with respect to the cyclic olefin-based resin.

[2] Thermoplastic resin The thermoplastic resin material of the present invention is not particularly limited as long as it can be used as a film after film formation. For example, as the thermoplastic resin used for polarizing plates, cellulose ester-based resins such as triacetyl cellulose (TAC), cellulose acetate propionate (CAP), and diacetyl cellulose (DAC), or cyclic resins can be used. Cyclic olefin resins such as olefin polymers (hereinafter also referred to as COP, cycloolefin resins), polypropylene resins such as polypropylene (PP), acrylic resins such as polymethyl methacrylate (PMMA), and polyparaffin Polyester resins such as ethylene phthalate (PET).

Among them, cyclic olefin-based resins or acrylic-based resins are preferable from the viewpoint of including optical properties such as retardation and physical properties such as durability.

[2.1] Cycloolefin resin The cycloolefin resin contained in the optical film of the present invention is preferably a polymer of a cycloolefin monomer, or a copolymer of a cycloolefin monomer and a copolymerizable monomer other than this.

As the cycloolefin monomer, a cycloolefin monomer having a norbornene skeleton is preferred, and a cycloolefin monomer having a structure represented by the following general formula (A-1) or (A-2) is preferred.

In the general formula (A-1), R ¹ to R ⁴ each independently represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a polar group. p represents an integer from 0 to 2. However, R ¹ to R ⁴ do not all represent hydrogen atoms at the same time, R ¹ and R ² do not represent hydrogen atoms simultaneously, and R ³ and R ⁴ do not represent hydrogen atoms simultaneously.

In general formula (A-1), as ^{the hydrocarbon group represented by R 1} to R ^{4 having} 1 to 30 carbon atoms, for example, a hydrocarbon group having 1 to 10 carbon atoms is preferable, and a hydrocarbon group having 1 to 5 carbon atoms is preferable. is better. For example, the hydrocarbon group having 1 to 30 carbon atoms may further have a linking group containing a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. Examples of such linking groups include divalent polar groups such as carbonyl groups, imino groups, ether bonds, silyl ether bonds, and thioether bonds. Examples of the hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, and the like.

For the general formula (A-1), ^{the examples of polar groups represented by R 1} to R ⁴ include carboxyl group, hydroxyl group, alkoxy group, alkoxycarbonyl group, aryloxycarbonyl group, amino group, amido group and cyano group base. Among them, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group and an aryloxycarbonyl group are also preferable, and an alkoxycarbonyl group and an aryloxycarbonyl group are preferable from the viewpoint of ensuring the solubility during film formation from a solution.

From the viewpoint of improving the heat resistance of the optical film, p in the general formula (A-1) is preferably 1 or 2. When p is 1 or 2, the obtained polymer becomes bulky and the glass transition temperature tends to increase.

In the general formula (A-2), R ⁵ represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. R ⁶ represents a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amide group, a cyano group, or a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom). p represents an integer from 0 to 2.

^{R 5} in the general formula (A-2) is preferably a hydrocarbon group having 1 to 5 carbon atoms, and preferably a hydrocarbon group having 1 to 3 carbon atoms.

In the general formula (A-2), R ⁶ represents a carboxyl group, a hydroxyl group, an alkoxycarbonyl group and an aryloxycarbonyl group. From the viewpoint of ensuring the solubility of the solution film formation, the alkoxycarbonyl group and the aryloxycarbonyl group are preferred. Oxycarbonyl is preferred.

p in the general formula (A-2) preferably represents 1 or 2 from the viewpoint of improving the heat resistance of the optical film. When p represents 1 or 2, the resulting polymer becomes bulky and the glass transition temperature tends to be raised.

The cycloolefin monomer having the structure represented by the general formula (A-2) is preferable from the viewpoint of improving solubility in organic solvents. Generally, organic compounds have lower crystallinity due to disintegration symmetry, so solubility in organic solvents is improved. ^{R 5} and R ⁶ in the general formula (A-2) are substituted with respect to the symmetry axis of the molecule, and only the carbon atoms constituting the ring on one side are substituted, so the symmetry of the molecule is low, that is, because of the general formula (A-2) Since the cycloolefin monomer of the shown structure has high solubility, it is suitable when manufacturing an optical film by the solution casting method.

The content ratio of the cycloolefin monomer having the structure represented by the general formula (A-2) in the polymer of the cycloolefin monomer is, for example, 70 mol with respect to the total of all the cycloolefin monomers constituting the cycloolefin resin % or more, preferably 80 mol % or more, preferably 100 mol %. When the cycloolefin monomer having the structure represented by the general formula (A-2) is contained in a certain amount or more, since the orientation of the resin is improved, the retardation (retardation) value is likely to increase.

Compounds 1 to 14, which are specific examples of cycloolefin monomers having a structure represented by the general formula (A-1), are shown below, and specific examples of the cycloolefin monomers having a structure represented by the general formula (A-2) are shown below. Compounds 15-34 are exemplified.

In the example of the cycloolefin monomer and the copolymerizable copolymerizable monomer, the copolymerization of the cycloolefin monomer and the ring-opening copolymerizable monomer and the copolymerization of the cycloolefin monomer and the addition copolymerizable monomer are included. Sex monomers, etc.

Examples of the ring-opening copolymerizable copolymerizable monomer include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene.

Examples of addition copolymerizable copolymerizable monomers include unsaturated double bond-containing compounds, vinyl-based cyclic hydrocarbon monomers, (meth)acrylates, and the like. Examples of the compound containing an unsaturated double bond include olefinic compounds having 2 to 12 (preferably 2 to 8) carbon atoms, and in this example, ethylene, propylene, butene, and the like are included. Examples of vinyl-based cyclic hydrocarbon monomers include vinylcyclopentene-based monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of (meth)acrylates include alkyl groups having 1 to 20 carbon atoms such as meth (meth)acrylate, 2-ethylhexyl (meth)acrylate, and cyclohexyl (meth)acrylate (Meth)acrylate.

The content ratio of the cycloolefin monomer in the copolymer of the cycloolefin monomer and the copolymerizable monomer is, for example, 20 to 80 mol %, preferably 30 to 70 mol %, with respect to the total of all monomers constituting the copolymer. .

Cycloolefin-based resin As mentioned above, a cycloolefin monomer having a norbornene skeleton, preferably a cycloolefin monomer having a structure represented by the general formula (A-1) or (A-2), is obtained by polymerizing or copolymerizing The polymer of this example contains the following.

(1) Ring-opening polymer of cycloolefin monomer (2) Ring-opening copolymer of a cycloolefin monomer and a copolymerizable monomer capable of ring-opening copolymerization therewith (3) Hydrogenated product of the ring-opening (co)polymer of the above (1) or (2) (4) Hydrogenated (co)polymer obtained by cyclizing the ring-opened (co)polymer of (1) or (2) above by Friedel-Crafts reaction (5) Saturated copolymer of cycloolefin monomer and compound containing unsaturated double bond (6) Addition copolymers of cycloolefin monomers and vinyl cyclic hydrocarbon monomers and their hydrogenated products (7) Interactive copolymer of cycloolefin monomer and (meth)acrylate The polymers of the above (1) to (7) can be obtained by any known method, for example, by the method described in JP 2008-107534 A or JP 2005-227606 A. For example, as the catalyst or solvent used for the above-mentioned (2) ring-opening copolymerization, for example, those described in paragraphs 0019 to 0024 of JP-A-2008-107534 can be used. As the catalyst used for the hydrogenation of the above (3) and (6), for example, those described in paragraphs 0025 to 0028 of JP 2008-107534 A can be used. As the acidic compound used for the above-mentioned (4) Friedel-Crafts reaction, for example, those described in paragraph 0029 of JP-A No. 2008-107534 can be used. As the catalyst used for the addition polymerization of the above (5) to (7), for example, those described in paragraphs 0058 to 0063 of JP-A No. 2005-227606 can be used. The cross-copolymerization reaction of the above (7) can be carried out, for example, by the method described in paragraphs 0071 and 0072 of JP-A No. 2005-227606.

Among them, the polymers of the above (1) to (3) and (5) are also preferred, and the polymers of the above (3) and (5) are preferred. That is, the cycloolefin-based resin contains a structural unit represented by the following general formula (B-1) and the following general formula from the viewpoint of increasing the glass transition temperature of the obtained cycloolefin-based resin and improving the light transmittance. At least one of the structural units represented by (B-2) is preferred, and the one containing only the structural unit represented by the general formula (B-2), or the structural unit represented by the general formula (B-1) and the general formula (B-2) is preferred. -2) Both sides of the structural units shown are preferred. The structural unit represented by the general formula (B-1) is a structural unit derived from the cycloolefin monomer represented by the aforementioned general formula (A-1), and the structural unit represented by the general formula (B-2) is derived from the aforementioned general formula (A- 2) Structural unit of the cycloolefin monomer shown.

In the general formula (B-1), X represents -CH=CH- or -CH ₂ CH ₂ -. R ¹ ~ R ⁴ and p are each of the general formula R (A-1) of ¹ ~ R ⁴ and p are synonymous.

In the general formula (B-2), X represents -CH=CH- or -CH ₂ CH ₂ -. R ⁵ ~ R ⁶ p in each general formula (A-2), and the R ⁵ ~ R ⁶ and p are synonymous.

The cycloolefin-based resin according to the present invention can be sold. Examples of commercially available cycloolefin resins include Arton G (eg, G7810, etc.), ArtonF, ArtonR (eg, R4500, R4900, R5000, etc.), and ArtonRX manufactured by JSR Corporation.

The intrinsic viscosity [η]inh of the cycloolefin resin ^{is preferably in the range of 0.2~5cm 3} /g, preferably in the range of 0.3~3cm ³ /g, preferably in the range of 0.4~1.5cm ^{3 for the measurement at 30°C} The range of /g is better.

The number average molecular weight (Mn) of the cycloolefin resin is preferably in the range of 8,000 to 100,000, preferably in the range of 10,000 to 80,000, and more preferably in the range of 12,000 to 50,000. The weight average molecular weight (Mw) of the cycloolefin resin is preferably in the range of 20,000 to 300,000, preferably in the range of 30,000 to 250,000, and more preferably in the range of 40,000 to 200,000. The number average molecular weight or the weight average molecular weight of the cycloolefin-based resin can be measured in terms of polystyrene by gel permeation chromatography (GPC).

<Gel permeation chromatography> Solvent: Dichloromethane Column: Shodex K806, K805, K803G (using the Showa Denko Co., Ltd. with 3 connections) Column temperature: 25℃ Sample concentration: 0.1% by mass Detector: RI Model 504 (manufactured by GLScience) Pump: L6000 (manufactured by Hitachi, Ltd.) Flow: 1.0mL/min Calibration curve: A calibration curve of 13 samples in the range of Mw=500 to 2,800,000 by standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) was used. 13 It is preferred that the samples be used at nearly equal intervals.

When the intrinsic viscosity [η]inh, the number average molecular weight and the weight average molecular weight are within the above ranges, the heat resistance, water resistance, chemical resistance, mechanical properties and film forming processability of the cycloolefin-based resin are improved.

The glass transition temperature (Tg) of the cycloolefin resin is usually 110°C or higher, preferably in the range of 110 to 350°C, preferably in the range of 120 to 250°C, and more preferably in the range of 120 to 220°C good. When Tg is 110° C. or higher, deformation under high temperature conditions is easily suppressed. On the other hand, when the Tg is 350° C. or lower, the molding process becomes easy, and the deterioration of the resin due to heat during the molding process is also easily suppressed.

The content of the cycloolefin-based resin is preferably 70% by mass or more, preferably 80% by mass or more, based on the film.

[2.2] Acrylic resin The acrylic resin of the present invention is a polymer of acrylate or methyl acrylate, and also contains copolymers with other monomers.

Therefore, methyl acrylate resin is also contained in the acrylic resin concerning this invention. Although the resin is not particularly limited, it is preferable that the methyl methacrylate unit is in the range of 50 to 99 mass %, and the other monomer unit that can be copolymerized is in the range of 1 to 50 mass %.

Examples of other units constituting the acrylic resin formed by copolymerization include alkyl methacrylates having 2 to 18 carbon atoms in the alkyl group, alkyl acrylates having 1 to 18 carbon atoms in the alkyl group, Hydroxyalkyl acrylates such as isobornyl methacrylate and 2-hydroxyethyl acrylate, α,β-unsaturated acids such as acrylic acid and methacrylic acid, acryl morpholine, N-hydroxyphenyl methacryloyl Acrylamide such as amine, N-vinylpyrrolidone, maleic acid, fumaric acid, itaconic acid and other unsaturated carboxylic acids containing unsaturated groups, aromatic vinyl such as styrene and α-methylstyrene Compounds, α,β-unsaturated nitriles such as acrylonitrile and methacrylonitrile, maleic anhydride, maleimide, N-substituted maleimide, glutarimide, glutaric anhydride, and the like.

From the above-mentioned unit, the monomer corresponding to the above-mentioned unit can be mentioned as a copolymerizable monomer which forms a unit except glutarimide and glutaric anhydride. That is, alkyl methacrylates having an alkyl group having 2 to 18 carbon atoms, alkyl acrylates having an alkyl group having 1 to 18 carbon atoms, isobornyl methacrylate, and 2-hydroxyethyl acrylic acid can be mentioned. Hydroxyalkyl acrylates such as esters, α, β-unsaturated acids such as acrylic acid and methyl acrylate, acrylamide such as acryl morpholine, N-hydroxyphenyl methacrylamide, N-vinyl pyrrolidone, Divalent carboxylic acids containing unsaturated groups such as maleic acid, fumaric acid, and itaconic acid, aromatic vinyl compounds such as styrene and α-methylstyrene, α,β- Unsaturated nitrile, maleic anhydride, maleimide, N-substituted maleimide and other monomers.

In addition, the glutarimide unit can be formed, for example, by reacting an intermediate polymer having a (meth)acrylate unit with a primary amine (imidizing agent) to undergo imidization (refer to Japanese Laid-Open Patent Publication). 2011-26563 Gazette).

The glutaric anhydride unit can be formed, for example, by heating an intermediate polymer having a (meth)acrylate unit (refer to Patent No. 4961164).

In the acrylic resin according to the present invention, among the above-mentioned constituent units, from the viewpoint of mechanical strength, isobornyl methacrylate, acryl morpholine, N-hydroxyphenylmethacrylamide, N-vinylpyrrolidone, styrene, hydroxyethyl methacrylate, maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride or glutarimide good.

Regarding the acrylic resin of the present invention, from the viewpoint of controllable dimensional changes to environmental changes in temperature and humidity, or from the viewpoint of the peelability from the metal support during film production, the drying properties of organic solvents, heat resistance and mechanical strength From the viewpoint of improvement, the weight average molecular weight (Mw) is preferably within the range of 50,000 to 1,000,000, preferably within the range of 100,000 to 1,000,000, and preferably within the range of 200,000 to 800,000. Excellent.

When it is 50,000 or more, heat resistance and mechanical strength are excellent, and when it is 1,000,000 or less, peelability from a metal support and drying property of an organic solvent are excellent.

There is no restriction|limiting in particular as a manufacturing method of the acrylic resin concerning this invention, Any of well-known methods, such as suspension polymerization, emulsion polymerization, block polymerization, or solution polymerization, can also be used. Among them, as a polymerization initiator, a general peroxide type and an azo type can be used, and a redox type can also be used. Regarding the polymerization temperature, suspension or emulsion polymerization is carried out in the range of 30 to 100°C, and bulk or solution polymerization is carried out in the range of 80 to 160°C. In order to control the reduced viscosity of the obtained copolymer, an alkyl mercaptan or the like can be used as a chain transfer agent to carry out the polymerization.

When the glass transition temperature Tg of the acrylic resin is in the range of 80 to 120° C., it is preferable from the viewpoint that the mechanical strength of the film can be maintained.

As the acrylic resin according to the present invention, a seller can be used. For example, Delpet60N, 80N, 980N, SR8200 (the above are manufactured by Asahi Kasei Chemical Co., Ltd.), Dianal BR52, BR80, BR83, BR85, BR88, EMB-143, EMB-159, EMB-160, EMB-161, EMB -218, EMB-229, EMB-270, EMB-273 (the above are manufactured by Mitsubishi Rayon (stock)), KT75, TX400S, IPX012 (the above are manufactured by Denki Industry (stock)), etc. Two or more types of acrylic resins can be used in combination.

The acrylic resin of the present invention preferably contains additives. As an example of the additives, the acrylic particles (rubber elastomer particles) described in International Publication No. WO 2010/001668 can be used to improve the mechanical strength of the film or the dimensional change rate. It is better to adjust and include. Examples of the sale of such multi-layered acrylic granular composites include "METABLENW-341" manufactured by Mitsubishi Rayon Corporation, "Kane Ace" manufactured by Kaneka Corporation, "Pararoid" manufactured by Kureha, and Roam "Acryloid" manufactured by and Hearth, "Staphyroid" manufactured by Aika, Inc., Chemisnow MR-2G, MS-300X (the above are manufactured by Soken Chemical Co., Ltd.), and "ParapetSA" manufactured by Kuraray Company, etc. Use or use 2 or more.

The volume average particle diameter of the acrylic particles is 0.35 μm or less, preferably in the range of 0.01 to 0.35 μm, more preferably in the range of 0.05 to 0.30 μm. When the particle diameter is more than a certain level, the film can be easily stretched under heating, and when the particle diameter is less than a certain level, the transparency of the obtained film is not easily impaired.

From the viewpoint of flexibility, the optical film of the present invention preferably has a flexural modulus (JIS K7171) of 1.5 GPa or less. The bending elastic modulus is preferably 1.3 GPa or less, more preferably 1.2 GPa or less. The flexural modulus varies depending on the type or amount of acrylic resin or rubber elastomer particles in the film. For example, the higher the content of rubber elastomer particles, the lower the flexural modulus. Moreover, when using the copolymer of alkyl methacrylate and alkyl acrylate, etc. rather than the homopolymer of an alkyl methacrylate as an acrylic resin, the bending elastic modulus can generally be made small.

[3] Other ingredients The optical film of the present invention may further contain other components other than those described above within a range that does not impair the effects of the present invention. Examples of other components include matting agents, ultraviolet absorbers, retardation adjusters (retardation raising agents, retardation reducing agents), plasticizers, antioxidants, photostabilizers, antistatic agents, release agents, and tackifiers. Among them, from the viewpoint of imparting unevenness to the surface of the optical film and imparting moderate lubricity, it is preferable that the optical film contains a matting agent.

(matting agent) The matting agent is microparticles. The fine particles may be inorganic fine particles or resin fine particles. Examples of inorganic fine particles include silica, titania, alumina, zirconia, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, silicic acid Microparticles of inorganic compounds such as magnesium and calcium phosphate. Among them, from the viewpoint of inorganic microparticles that are not easy to increase the haze value of the optical film and can effectively reduce the friction coefficient, silica microparticles are preferred.

Examples of silica fine particles include AEROSIL200V, AEROSILR972V, and AEROSILR812 (the above are manufactured by Nippon Aerosil Co., Ltd.).

Examples of resin fine particles include fine particles of silicone resin, fluororesin, and acrylic resin. Among them, silicone resin microparticles are also preferable, and resin microparticles having a three-dimensional network structure are especially preferable. In the example of resin microparticles, TOSPEARL 103, 105, 108, 120, 145, 3120, and 240 are contained (the above are manufactured by Toshiba Silicon Oxygen Co., Ltd.).

The average particle diameter of the primary particles of the fine particles is preferably in the range of 0.005 to 0.4 μm, and more preferably in the range of 0.01 to 0.3 μm. These fine particles may be contained as secondary aggregates having a particle diameter of 0.05 to 0.3 μm.

The content of the fine particles is preferably in the range of 0.01 to 3.0 mass %, preferably in the range of 0.01 to 2.0 mass %, relative to the optical film. In addition, the dynamic friction coefficient of the surface of the optical film is preferably in the range of 0.2 to 1.0.

[4] Manufacturing method of optical film [4.1] Physical properties of optical films (Phase difference Ro) For example, from the viewpoint of being used as a λ/4 retardation film for the optical film, the phase difference Ro in the in-plane direction measured in an environment with a measurement wavelength of 550 nm and 23° C. and 55% RH is preferably in the range of 100 to 170 nm. Those in the range of 130 to 150 nm are preferred.

Ro is defined by the following formula.

Formula (1): Ro = in _{(n x -n y) × d} ( formula (1), n _x represents the in-plane slow axis direction of the film (the direction of maximum refractive index change) of the refractive index, n _y represents a film It is the refractive index perpendicular to the in-plane retardation axis, and d represents the thickness of the film (nm).) The in-plane retardation axis of the optical film can be scanned by an automatic complex refractometer Axo (Axo Scan Mueller Matrix Polarimeter: AXOMETRIX Company system) was confirmed. When the optical film is used as a λ/4 retardation film, the angle of the optical film of the in-plane slow axis of the optical film with respect to the width direction is preferably in the range of 40 to 50°, more preferably in the range of 43 to 47°.

Ro can be determined by the following method.

1) Condition the optical film for 24 hours in an environment of 23°C and 55%RH. The average refractive index of the thin film was measured with an Abbe refractometer, and the thickness d was measured with a commercially available micrometer.

2) The retardation Ro at the measurement wavelength of 550 nm of the film after humidity conditioning was measured in an environment of 23°C and 55% RH using an automatic complex refractometer Axo scan (Axo Scan Mueller Matrix Polarimeter: manufactured by AXOMETRIX).

The retardation Ro of the optical film can be adjusted by, for example, the monomer composition of the cycloolefin-based resin or the stretching conditions.

(residual solvent amount) The optical thin film may further contain a residual solvent because it is preferably formed by a solution casting method. The residual solvent content is preferably 700 ppm or less for the optical film, and preferably in the range of 30 to 700 ppm. The content of the residual solvent can be adjusted by the drying conditions of the dopant cast on the support in the manufacturing step of the optical film.

The residual solvent content of the optical film can be determined by headspace gas chromatography. In the headspace gas chromatography method, the sample is sealed in a container, heated, and the gas in the container is quickly injected into the gas chromatography method in a state where the container is full of volatile components, and mass analysis and compounding are carried out. Quantitative volatile components under the identification. In the headspace method, it is possible to observe the total absorption peaks of volatile components by gas chromatography, and at the same time, it is possible to combine the volatilization with high precision by the analysis method using the interaction of electromagnetic gas. Quantitative substances or monomers.

(thickness) Although the thickness of the optical film of the present invention is not particularly limited, it is preferably in the range of 10 to 80 μm, and more preferably in the range of 10 to 60 μm.

[4.2] Manufacturing method of optical film The optical film of the present invention can be produced through the following steps: 1) a step of preparing a dopant containing the above-mentioned cycloolefin-based resin or acrylic resin, the above-mentioned pigment compound and a solvent, and 2) casting the obtained dopant on a support A step of drying and peeling to obtain a cast film after applying, and 3) a step of extending the obtained cast film. In addition, the optical film of the present invention can be further manufactured through the following steps: 4) a step of drying the stretched cast film, 5) a step of cutting both ends of the obtained optical film, and applying an embossing process, and 6) Roll up step.

In the step of 1) (dopant preparation step), a dopant is prepared by dissolving or dispersing a cycloolefin-based resin or an acrylic resin and a dye compound in a solvent.

The solvent used for the dopant contains at least an organic solvent (good solvent) capable of dissolving the cycloolefin-based resin. Examples of good solvents include chlorine-based organic solvents such as dichloromethane, and non-chlorine-based organic solvents such as methyl acetate, ethyl acetate, acetone, and tetrahydrofuran. Among them, dichloromethane is also preferred.

The solvent used for the dopant may further contain a weak solvent. Examples of the weak solvent include linear or branched aliphatic alcohols having 1 to 4 carbon atoms. When the ratio of the alcohol in the dopant increases, the film-like product tends to gel, and the peeling from the metal support becomes easy. Examples of linear or branched aliphatic alcohols having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol . Among these, ethanol is preferable from the viewpoints of the stability of the dopant, the relatively low boiling point, and the good drying properties.

For the step of 2) (casting step), the obtained dopant is cast on a support. Casting of the dopant can be performed by discharging from a casting die.

The dopant cast on the support is evaporated from the support by a peeling roller until it can be peeled off. As a method of evaporating the solvent, a method of exposing the casted dopant to the wind, a method of transferring heat from the back surface of the support through a liquid, a method of transferring heat from the front and back sides by radiant heat, etc. .

Then, the cast film obtained by evaporating the solvent is peeled off by a peeling roller.

Although the residual solvent amount of the cast film on the support at the time of peeling depends on drying conditions, the length of the support, and the like, for example, it can be in the range of 50 to 120 mass %. When peeling is performed in a state with a large amount of residual solvent, the cast film is too soft, the flatness is easily damaged during peeling, and wrinkles and vertical streaks are easily generated due to peeling tension. amount of residual solvent. The residual solvent amount is defined by the following formula.

Residual solvent amount (mass %)=(mass of cast film before heat treatment-mass of cast film after heat treatment)/(mass of cast film after heat treatment)×100 The heat treatment at the time of measuring the residual solvent amount was a heat treatment at 115° C. for 1 hour.

In the step (stretching step) of 3), the cast film obtained by peeling from the support is stretched.

The stretching may be performed in accordance with the required optical properties, and it is preferable to perform the stretching in any one or more directions of the width direction (TD direction), the conveyance direction (MD direction), and the oblique direction. For example, when producing an optical film that functions as a λ/4 retardation film, it is preferable to stretch in an oblique direction in the past.

Although the stretching ratio also depends on the required optical properties, for example, when used as a λ/4 retardation film, it is preferably in the range of 1.05 to 4.0 times, and preferably in the range of 1.5 to 3.0 times.

The stretching magnification (fold) is defined as the size of the film in the stretching direction after stretching/the size of the film in the stretching direction before stretching. In addition, when biaxial stretching is performed, the above-mentioned stretching ratio is preferable for each of the TD direction and the MD direction.

The stretching temperature (drying temperature during stretching) is the same as the above, when the glass transition temperature of the cycloolefin-based resin is taken as Tg, it is preferably in the range of (Tg+2) ~ (Tg+50) °C, and (Tg+ 5)~(Tg+30)℃ range is better. If the stretching temperature is (Tg+2)°C or higher, the solvent can be easily volatilized moderately, and the stretching tension can be easily adjusted to an appropriate range. Extensibility is not easily compromised. The stretching temperature is the same as described above, and it is preferable to measure the ambient temperature such as (a) the temperature inside the stretching machine.

The amount of residual solvent in the film at the start of stretching is preferably the same as the amount of residual solvent in the film at the time of peeling, for example, it is preferably in the range of 20 to 30 mass %, and it is preferably 25 to 30 mass % range is better.

The extension of the film in the TD direction (width direction) can be performed, for example, by a method (tenter method) in which both ends of the film are fixed with clips or pins, and then the gaps between the clips or pins are spread in the advancing direction. The stretching of the film in the MD direction can be performed, for example, by a method (roll method) in which a difference in peripheral speed is set for a plurality of rolls and the difference in the peripheral speed of the rolls is used therebetween. In particular, the tenter method in which both ends of the cast film are sandwiched by clips or the like and stretched is preferable because the flatness and dimensional stability of the film can be improved. By extending the cast film in both the MD direction and the TD direction, it is preferable that the MD direction and the TD direction are extended in the diagonal cross direction (diagonal stretching).

For the step (drying step) of 4), the stretched cast film is further dried to obtain an optical film.

The drying of the cast film can be performed while conveying the cast film by, for example, a plurality of conveying rollers (for example, a plurality of conveying rollers arranged in a staggered shape when viewed from the side). The drying means is not particularly limited, and hot air, infrared rays, heating rollers, or microwaves can be used. From the viewpoint of simplicity, hot air drying is preferable.

In the step of 5) (cutting/embossing step), both ends of the obtained optical film in the width direction are cut. Both ends of the optical film can be cut by a slitter.

Next, embossing (knurling) is applied to both ends in the width direction of the optical film. Embossing can be performed by pressing heated embossing rollers against both ends of the optical film. Fine concavities and convexities are formed on the surface of the embossing roller, and the embossing roller is pressed against both ends of the optical film to form concavities and convexities at both ends. By such an embossing process, it is possible to suppress as much as possible the roll-up deviation or the closing (the films are attached to each other) in the next roll-up step.

In the step of 6) (winding step), the resulting optical film is wound up to obtain a roll body.

That is, it becomes a roll body by winding up with a core, conveying an optical film. The winding method of the optical film may be a method using a generally used winding machine, such as a torque method, a constant tension method, a taper tension method, and a programmed tension control method with constant internal stress.

The roll length of the optical film in the roll body is preferably in the range of 1000~7200m. The width of the optical film is preferably in the range of 1000 to 3000 mm.

[5] Other functional layers The optical film of the present invention preferably has a functional layer, and the functional layer is preferably a compound having the structure represented by the aforementioned general formula (1). Examples of the functional layer include a hard coat layer, an anti-static layer, an anti-reflection layer, an easy-slip layer, an adhesive layer, an anti-glare layer, a barrier layer, and the like. However, when an organic EL image display device is mounted, it is necessary to improve the scratch resistance. It is better to provide a hard coating layer.

[5.1] Hard coating layer The hard coat layer used in the present invention is preferable from the viewpoint of having excellent mechanical film strength (scratch resistance, pencil hardness) due to the active ray curing resin. That is, by irradiation with active rays such as ultraviolet rays or electron rays (also referred to as active energy rays), it becomes a layer mainly composed of a resin hardened by a crosslinking reaction. As the active ray hardening resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active ray hardening resin layer is formed by curing it by irradiating an active ray such as ultraviolet rays or an electron beam. Typical examples of the active ray-curable resin include ultraviolet-curable resins, electron beam-curable resins, and the like. Among them, resins cured by ultraviolet irradiation are excellent in mechanical film strength (scratch resistance, pencil hardness). Look good. As the UV-curable resin, for example, UV-curable acrylate-based resin, UV-curable urethane-acrylate-based resin, UV-curable polyester acrylate-based resin, UV-curable epoxy acrylate-based resin, UV-curable epoxy acrylate-based resin, UV-curable Curable polyol acrylate-based resins, UV-curable epoxy resins, or the like are preferable, and among them, UV-curable acrylate-based resins are also preferable.

Examples of sales include Adeka Putmer N series, Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (the above are manufactured by Sanyo Chemical Industry Co., Ltd.) , AronixM-6100, M-8030, M-8060, AronixM-215, AronixM-315, AronixM-313, AronixM-327 (the above are manufactured by Donga Synthetic Co., Ltd.), NK-ester A-TMM-3L, NK- Ester AD-TMP, NK-ester ATM-35E, NK-ester A-DOG, NK-ester A-IBD-2E, A-9300, A-9300-1CL (the above are manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), PE- 3A (Kyoei Corporation Chemical Co., Ltd.), etc. The said active ray hardening resin may be used individually or in mixture of 2 or more types.

Moreover, it is preferable that the hard coating layer contains a photopolymerization initiator in order to promote the hardening of the active ray hardening resin. As the photopolymerization initiator dosage, the mass ratio of photopolymerization initiator:active ray hardening resin=20:100~0.01:100 is preferable. Specific examples of the photopolymerization initiator include alkylphenone systems, acetophenone, benzophenone, hydroxybenzophenone, Miller's ketone, α-aminooxime ester, thioxanthone, etc., and derivatives thereof is not particularly limited.

As such a photopolymerization initiator, a commercially available product may be used, for example, IRGACURE 184, IRGACURE 907, and IRGACURE 651 manufactured by BASF Japan Co., Ltd. are preferably exemplified.

The thickness of the hard coat layer is preferably within the range of 0.1 to 50 μm, and more preferably within the range of 1 to 20 μm, from the viewpoints of the improvement of the hard coatability and the improvement of the transparency of the optical film. The method for forming the hard coat layer is not particularly limited. For example, after preparing a coating liquid for forming a hard coat layer containing the above components, the coating liquid is applied with a wire bar or the like, and the coating liquid is cured with heat or ultraviolet rays. A method of forming a hard coat layer, etc. In the hard coat layer, it is preferable from the viewpoint of further improving light resistance and imparting scratch resistance by containing the compound having the structure represented by the general formula (1) according to the present invention. It is preferable to contain in the range of 0.1-40 mass % with respect to the said ultraviolet curable resin, and it is preferable to exist in the range of 0.1-20 mass %.

[6] Polarizing plate The polarizing plate of the present invention includes a polarizer and the optical film of the present invention disposed on at least one side.

FIG. 1 is a cross-sectional view showing the configuration of the polarizing plate 100 . As shown in FIG. 1 , the polarizing plate 100 of the present invention has a polarizer 101 , an optical film 102 of the present invention arranged on one side, an opposite film 103 arranged on the other side, and arranged between the polarizer 101 and the optical film 102 and two adhesive layers 104 between the polarizer 101 and the opposite thin film 103 .

(for polarizer 101) The polarizer 101 is an element that only transmits light of a polarization plane in a certain direction, and is a polyvinyl alcohol-based stretched film mixed with iodine or a dichroic dye.

The thickness of the polarizer 101 is in the range of 5 to 40 μm, preferably in the range of 5 to 30 μm, and particularly preferably in the range of 5 to 20 μm.

(For Optical Film 102) The optical film 102 can be used as a retardation film, for example, as a λ/4 retardation film used in a circularly polarizing plate of an organic EL image display device.

For the in-plane of the optical film 102 , the angle formed by the in-plane retardation axis of the optical film 102 with respect to one side of the outer shape of the rectangular film is preferably in the range of 30° to 60°, preferably 45°. And the aforementioned side corresponds to the width direction of the elongated optical film 102 . In addition, the angle formed between the in-plane retardation axis of the optical film 102 and the absorption axis (or transmission axis) of the polarizer 101 is preferably in the range of 30° to 60°, preferably 45°.

The optical film 102 may further have other layers (for example, a hard coat layer, a low refractive index layer, and an antireflection layer) disposed on the opposite side of the polarizer 101 according to the application. In addition, the optical film 102 may further have a layer disposed on the polarizer 101. The easy bonding layer on the side of 101 (not shown).

(For the opposing film 103) The opposite film 103 can be the optical film of the present invention, or other optical films other than this (ie, protective film). Preferably, the optical film of the present invention is used and has a hard coating layer on the outermost surface.

Examples of commercially available protective films include commercially available cellulose ester films (such as Konica Minolta Tuck KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UA, KC8UA, KC2UAH, KC4UAH, KC6UAH, above Konica Minolta Co., Ltd., Fuji TuckT40UZ, Fuji TuckT60UZ, Fuji TuckT80UZ, Fuji TuckTD80UL, Fuji TuckTD60UL, Fuji TuckTD40UL, Fuji TuckR02 TuckR06, the above Fuji Film Co., Ltd.).

As the commercially available cycloolefin film, various grades of Zeonoa Film (R), a molded product of a cycloolefin polymer (COP) manufactured by Nippon Zeon, are preferably used.

The thickness of the opposing thin film 103 is, for example, in the range of 5 to 100 μm, preferably in the range of 40 to 80 μm.

(for the next layer 104) The subsequent layers 104 can be respectively disposed between the polarizer 101 and the optical film 102 , and between the polarizer 101 and the opposite film 103 .

The adhesive layer 104 may be a layer obtained from a water-based adhesive described later, or may be a cured product layer of an ultraviolet curable adhesive.

The thickness of the adhesive layer 104 is not particularly limited, but is, for example, in the range of 0.01 to 10 μm, preferably about 0.01 to 5 μm.

The polarizing plate 100 may be in a long shape, or may be in a sheet shape obtained by cutting the long polarizing plate along the width direction.

(Physical properties) (T ₁ /T ₂ ) When an aluminum reflective material is laminated on an optical film of a polarizing plate with an adhesive layer interposed therebetween, the light reflectivity of the polarizing plate at a wavelength of 460 nm is taken as T ₁ (%), and the wavelength of 650 nm is taken as T 1 (%). When the light reflectance of is T ₂ (%), it is preferable that the polarizing plate satisfies the following formula (2).

Formula (2): 0 < T ₁ /T ₂ <2.6 _{If T 1} /T _{2 is} less than 2.6, the reflectivity of light with a wavelength of 460 nm will not be too high, and the leakage of reflected light adjacent to this wavelength can be suppressed, so for example The color of reflected light in an organic EL image display device can be improved. In addition, when T ₁ /T ₂ exceeds 0, for example, in an organic EL image display device, light emission in the above-mentioned wavelength region is difficult to be inhibited by a dye compound, so that the decrease in luminance can be suppressed. T ₁ /T ₂ is preferably 2.5 or less.

(Color difference ΔE(a ^* b ^* )) Further, the color difference ΔE(a ^* b ^* ) of the polarizing plate is preferably less than 25, and preferably less than 20. If the color difference ΔE (a*b*) of the polarizing plate is within the above range, for example, the color of the reflected light in the organic EL image display device can be improved.

_{T 1} /T ₂ and color difference ΔE (a ^* b ^* ) of the polarizing plate can be measured by the following procedure.

1) On the optical film of the polarizing plate, laminate an aluminum reflective material with an adhesive layer interposed therebetween, and use it as a polarizing plate sample. An acrylic adhesive was used as the adhesive.

2) The spectral reflectance and color difference ΔE (a ^* b ^* ) of the obtained polarizing plate sample were measured by the SCI method with a spectrophotometer (CM3700d manufactured by Konica Minolta).

The T ₁ /T _{2 of the} polarizing plate and the color difference ΔE (a ^* b ^* ) can be adjusted by the type and content of the dye compound represented by the general formula (1).

(Manufacturing method of polarizing plate 100 ) The polarizer 100 can be obtained by the step of laminating the polarizer 101 and the optical film 102 of the present invention via an adhesive. As the adhesive, a water-based adhesive or an ultraviolet curing adhesive is used.

＜Water-based adhesive＞ Examples of the water-based adhesive include a water-based adhesive containing a polyvinyl alcohol-based resin (completely saponified polyvinyl alcohol aqueous solution, etc.).

＜Ultraviolet curing adhesive＞ The ultraviolet curable adhesive composition is a photo-radical polymerization-type composition, a photo-cationic polymerization-type composition, or a mixed-type composition using these together.

Examples of the photo-radical polymerizable composition include a radically polymerizable compound having a polar group such as a hydroxyl group or a carboxyl group described in Japanese Patent Laid-Open No. 2008-009329, and a radically polymerizable compound that does not contain a polar group composition.

The radically polymerizable compound is preferably a compound having a radically polymerizable ethylenically unsaturated bond. Preferred examples of the compound having a radically polymerizable ethylenically unsaturated bond include a compound having a (meth)acryloyl group. In the example of the compound which has a (meth)acrylamide group, an N-substituted (meth)acrylamide-based compound and a (meth)acrylate-based compound are contained. (Meth)acrylamide means acrylamide or methacrylamide.

In an example of a photocationic polymerizable composition, as disclosed in Japanese Patent Laid-Open No. 2011-028234, (α) a cationically polymerizable compound, (β) a photocationic polymerization initiator, and a compound having a length of 380 nm longer than (γ) is contained. A photosensitizer that exhibits maximum absorption of light at a wavelength, and an ultraviolet curable adhesive composition containing a (δ) naphthalene-based photosensitizer.

An example of using an ultraviolet curable adhesive will be described below. The polarizing plate 100 of the present invention can be obtained through the following steps: 1) on the bonding surface of the optical film and the opposite film, perform a pre-processing step (pre-processing step) to be easily bonded; 2) combine the polarizer with the optical film ( or the opposite film), the step of laminating with an ultraviolet adhesive, and 3) the step of curing the ultraviolet adhesive by irradiating the laminate obtained by lamination with ultraviolet rays (hardening step).

(1) Pre-processing steps Easy-bonding treatment is performed on the bonding surface of the optical film and the polarizer of the opposite film. Examples of easy-bonding treatments include corona treatment and plasma treatment.

(2) Fitting step The ultraviolet curable adhesive is applied to at least one of the polarizer and the optical film (or the opposite film). The coating method of the ultraviolet curable adhesive is not particularly limited, and examples thereof include a doctor blade, a wire bar, a die coating, a Comma coater, a gravure coater, and the like.

Then, the polarizer and the optical film or the opposite film can be bonded together by an ultraviolet curable adhesive. Then, both sides of the bonded laminate are sandwiched and pressed by pressing rollers or the like. The material of the pressure roller can be metal or rubber.

(3) Hardening step Next, ultraviolet rays are irradiated to the laminate bonded by the UV-curable adhesive to cure the UV-curable adhesive. Thereby, the polarizer and the optical film or the opposing film are bonded by an ultraviolet curable adhesive. In addition, the curing of the ultraviolet curable adhesive on one side of the polarizer and the curing of the ultraviolet curable adhesive on the other side of the polarizer may be performed sequentially or simultaneously. From the viewpoint of improving the manufacturing efficiency of the polarizing plate, it is preferable that the curing of the ultraviolet-curable adhesive on one side of the polarizer and the curing of the ultraviolet-curable adhesive on the other side of the polarizer are performed simultaneously.

The irradiation conditions of the ultraviolet rays may be those that can cure the UV-curable adhesive. For example, the integrated light intensity ^{is preferably in the range of 50-1500 mJ/cm 2} , and preferably in the range of 100-500 mJ/cm ² .

Although the linear velocity at the time of manufacture of a polarizing plate depends on the hardening time of an adhesive agent, for example, the range of 1-500m/min is preferable, and the range of 5-300m/min is preferable. When the line speed is 1 m/min or more, the productivity can be easily improved, and the damage to the optical film or the opposing film can be reduced. In addition, when the line speed is 500 m/min or less, the curing of the ultraviolet curable adhesive becomes sufficient, and good adhesiveness is easily obtained.

In this way, in the curing step, it may become a high-temperature environment by ultraviolet irradiation, heating to promote curing, or the like. Moreover, even if an adhesive agent is an aqueous adhesive agent, it becomes a high temperature environment by heating etc. which are intended to promote adhesion or drying of the adhesive agent.

On the other hand, since the optical film of the present invention has excellent light resistance and durability, even if the polarizer and the optical film are bonded to a high temperature environment, a polarizing plate in which light leakage is suppressed can be obtained. By suppressing the light leakage of the polarizing plate, the organic EL image display device having the polarizing plate can suppress the weak light leakage caused by the reflection of external light during black display.

[7] Image display device The optical film of the present invention can be used as an optical film (retardation film, protective film) of image display devices such as organic EL image display devices and liquid crystal display devices. Among them, the optical film of the present invention can also be preferably used as a retardation film (λ/4 retardation film) of an organic EL image display device.

[7.1] Organic EL image display device FIG. 2 shows an exploded cross-sectional view of the organic EL image display device 200 .

The organic EL image display device 200 includes an organic EL element 300 (display unit), a polarizing plate 100 (circular polarizing plate), and an adhesive layer 400 disposed therebetween.

The organic EL element 300 has a metal electrode 302, a light-emitting layer 303, a transparent electrode (ITO or the like) 304, and a sealing layer 305 on a substrate 301 such as glass or polyimide in this order. The metal electrode 302 can also be composed of a reflective electrode and a transparent electrode.

The metal electrode 302 may function as a cathode. When the metal electrode 302 is intended to facilitate electron injection and improve the luminous efficiency, it is preferable to use a material with a small work function, and usually Mg-Ag and Al-Li are used.

The light-emitting layer 303 is a laminate of organic thin films, such as a hole-injecting layer made of triphenylamine derivatives and the like and a light-emitting layer made of fluorescent organic solids such as anthracene, or a laminate of such a light-emitting layer and Laminates of electron injection layers made of perylene derivatives or the like, laminates of these hole injection layers, light emitting layers, and electron injection layers, etc.

The transparent electrode 304 functions as an anode. The transparent electrode 304 is usually made of a transparent conductor such as indium tin oxide (ITO).

Then, by inputting a voltage between the metal electrode 302 and the transparent electrode 304, holes and electrons are injected into the light-emitting layer 303, and the energy generated by the recombination of these holes and electrons will excite the fluorescent substance, and the excitation When the activated fluorescent substance returns to the substrate state, it emits light and emits light.

The polarizing plate 100 is disposed on the identification side of the organic EL element 300 . The polarizing plate 100 is the aforementioned polarizing plate 100 (refer to FIG. 1 ), and the optical film 102 (λ/4 retardation film) is arranged between the organic EL element 301 and the polarizer 101 . The angle formed by the transmission axis (or absorption axis) of the polarizer 101 and the in-plane retardation axis of the optical film 102 is as described above, preferably 45° (or 135°).

It is preferable that the opposite film 103 further has a hard coating layer (not shown) disposed on the identification side (the opposite side of the polarizer 101 ). The hard coating layer can not only prevent the surface scratches of the organic EL image display device, but also reduce the bending of the polarizing plate 100 . In addition, an antireflection layer may be further formed on the hard coat layer.

The next layer 400 is disposed between the organic EL element 300 and the polarizing plate 100, and is bonded together. Examples of the adhesive constituting the adhesive layer 400 include thermosetting adhesives (epoxy thermosetting adhesives, urethane thermosetting adhesives, acrylic thermosetting adhesives, etc.), thermal Adhesives, etc. (rubber-based hot-melt adhesive, polyester-based hot-melt adhesive, polyolefin-based hot-melt adhesive, ethylene-vinyl acetate resin-based hot-melt adhesive, polyurethane resin hot-melt adhesive agent, etc.).

(effect) In the organic EL image display device 200, when a voltage is input to the metal electrode 302 and the transparent electrode 304, electrons are injected from the metal electrode 302 serving as a cathode to the light-emitting layer 303, and holes are injected from the transparent electrode 304 serving as an anode. By recombining the two with the light-emitting layer 303 , the visible light emission corresponding to the light-emitting characteristics of the light-emitting layer 303 is generated. The light generated by the light emitting layer 303 is directly or reflected by the metal electrode 302 , and then extracted to the outside through the transparent electrode 304 and the polarizer 100 .

The light-emitting layer 303 can be formed as an extremely thin film with a thickness of about 10 nm. Therefore, similarly to the transparent electrode 304, the light-emitting layer 303 also transmits light almost completely. As a result, the light incident from the outside of the organic EL image display device 200 when not emitting light passes through the sealing layer 305, the transparent electrode 304, and the light-emitting layer 303, and reaches the metal electrode 302, is reflected by the metal electrode 302, and passes through the light-emitting layer again. 303 , the transparent electrode 302 and the sealing layer 305 go out to the surface side of the organic EL device 200 . At this time, the optical film 102 can suppress leakage of the light reflected by the metal electrode 302 to the surface side of the organic EL image display device 200, thereby reducing external light reflection.

That is, when it is not emitting light, half of the external light incident from the outside of the organic EL image display device 200 by indoor lighting or the like is absorbed by the polarizer 101 of the polarizer 100 , but the remaining half is not absorbed. It transmits as linearly polarized light and is incident on the optical film 102 (λ/4 retardation film). The light incident on the optical film 102 is converted into circularly polarized light because the transmission axis of the polarizer 101 and the in-plane retardation axis of the optical film 102 intersect at 45° (or 135°).

When the circularly polarized light emitted from the optical film 102 is mirror-reflected by the metal electrode 302 of the organic EL element 300, the phase is reversed by 180 degrees, and becomes the reversed circularly polarized light. When the reflected light is incident on the optical film 102, it is converted into linearly polarized light of the polarizer 101 perpendicular to the transmission axis (parallel to the absorption axis), so it is absorbed by the polarizer 101 and can be prevented from being emitted to the outside.

Then, in the present invention, the optical film 102 containing a specific dye compound is used. Thereby, the optical film 102 can also convert light in a specific wavelength region (in the cycloolefin resin film containing no dye compound, it is not converted into a desired linearly polarized light) into the polarized light 101 perpendicular to the transmission axis (to the absorption axis). parallel) linearly polarized light. Thereby, the reflected light in the specific wavelength region can suppress the decrease in the color of the reflected light caused by the leakage of the transmission axis of the transmitted polarizer 101 . Moreover, even if the optical film 102 contains a dye compound, it is excellent in light resistance, and by this, display unevenness can be suppressed. [Example]

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In addition, the representation of "part" or "%" is used in the examples, and unless otherwise specified, "part by mass" or "% by mass" is represented.

[Example 1] 1. Materials of optical films (1) Cycloolefin resin ≪Synthesis of cycloolefin resin 1≫ 100 parts by mass of purified toluene and 100 parts by mass of norbornene carboxylate methyl ester (refer to the following structural formula A) were put into the reactor. Next, dissolve ethylhexanoate-Ni in toluene 25 mmol% (to monomer mass), tris(pentafluorophenyl) boron 0.225 mol % (to monomer mass), and dissolve triethylaluminum in toluene 0.25 mol% (with respect to the monomer mass) was put into the reaction kettle, and the reaction was carried out for 18 hours while stirring at room temperature. After the completion of the reaction, the reaction mixture was put into excess ethanol to form a polymer precipitate. The precipitate was purified, and the obtained solid content was dried under vacuum at 65°C for 24 hours to obtain a cycloolefin resin (P-1) (weight average molecular weight Mw: 140,000, Tg: 140°C). And the weight average molecular weight was measured by the method mentioned above.

(2) Pigment compounds The exemplified dye compounds and comparative compounds described in Table I were prepared, and the energy level (eV) of the HOMO was calculated.

The energy level of the HOMO calculated from the molecular orbitals of the exemplified dye compound having the structure represented by the general formula (1) and the comparative compound can be calculated as, as a calculation method, B3LYP can be used as a functional, and 6- can be used as a basis function. The molecular orbital calculation of 31G(d) is calculated using a software, and the software is not particularly limited, and any one can be used to obtain it in the same manner.

In the present invention, as software for molecular orbital calculation, Gaussian09 (Revision C. 01, M. J. Frisch, et al, Gaussian, Inc., 2010.) manufactured by Gaussian, Inc. was used for calculation. The energy level value of the HOMO of the calculation result is recorded in Table I.

≪Synthesis examples of dye compounds≫

<Exemplary dye compound 9>

1 g of compound (9-1) and 0.277 g of malononitrile were measured in a 100 mL three-headed piston, and 18 mL of toluene was added and dissolved. Next, after dropping 0.332 g of morpholine, the mixture was heated to reflux for 4 hours. After the completion of the reaction, the solvent was removed under reduced pressure, 5 mL of methanol was added, and the mixture was stirred in a suspended state. The precipitate was filtered and dried to obtain 0.33 g of powder of the exemplified pigment compound 9 (yield 28%). The structure was confirmed by NMR.

<Exemplary dye compound 23>

1 g of compound (23-1) and 0.497 g of malononitrile were weighed into a 100 mL 3-headed piston, and 40 mL of toluene was added to dissolve it. Next, 0.596 g of morpholine was added dropwise, followed by heating under reflux for 4 hours. After the completion of the reaction, the solvent was removed under reduced pressure, 5 mL of methanol was added, and the mixture was stirred in a suspended state. The precipitate was filtered and dried to obtain 0.24 g of powder of the exemplified pigment compound 23 (yield: 18%). The structure was confirmed by NMR.

(Measurement of absorption maximum wavelength) The absorption maximum wavelength of the above compound was obtained by measuring the absorption spectrum in dichloromethane of the pigment compound using an ultraviolet visible spectrophotometer UV-2450 manufactured by Shimadzu Corporation, and described in Table II. In addition, the "absorption maximum wavelength" in the invention refers to the wavelength (nm) at which the maximum and maximum absorbance (absorption intensity) of the absorption spectrum of the compound obtained when the absorption spectrum of the compound is measured.

2. Fabrication and evaluation of optical films <Production of Optical Film 101> (Preparation of fine particle additive solution) The following components were stirred and mixed in a dissolving apparatus for 50 minutes, and then dispersed with Menton Gorin. And it disperse|distributed by a mill, and further made the particle diameter of a secondary particle into predetermined size. This fine Mett NF manufactured by Nippon Seiko Co., Ltd. was filtered to prepare a fine particle addition solution.

Fine particles (AEROSILR812: primary average particle diameter manufactured by Nippon Aerosil: 7nm, apparent density 50g/L): 4 parts by mass Dichloromethane: 48 parts by mass Ethanol: 48 parts by mass

(modulation of dopant) The following components were put into an airtight container with sufficient stirring, and the temperature was raised to 80° C. and held for 1 hour. Next, after cooling to 30° C., the dopant A-1 was obtained by filtering through a filter with a pore size of 5 μm.

Cycloolefin resin 1: 100 parts by mass Dichloromethane: 302 parts by mass Ethanol: 18 parts by mass Exemplary pigment compound 1: 0.1 part by mass Additive solution of fine particles: 10 parts by mass

(Fabrication of Optical Film 101) On the endless metal support driven at a speed of 30m/min, cast the prepared dopant from the casting die, and face the drying air at 40°C on the support, and dry until a flow with self-supporting properties is obtained. Extended film (film). Then, it cooled to 10 degreeC, and the cast film was peeled from a support body. After that, the peeled cast film was dried at 110° C. for 30 minutes, and then stretched to a magnification of 2 times in a direction (oblique direction) of 45° in the width direction at 170° C. Thereby, the optical film 101 with a film thickness of 40 μm having an in-plane slow axis in a direction of about 45° in the width direction was obtained. The optical film 101 is a film having a retardation value Ro of 145 nm confirmed by the aforementioned evaluation method of retardation value and functioning as a λ/4 plate.

<Production of Optical Films 102~119> The optical films 102 to 119 were produced in the same manner as in the production of the optical film 101, except that the exemplified dye compounds were changed to those described in Table III.

≪Assessment≫ <Light transmittance> The light transmittance was measured using a spectrophotometer (U-3300 manufactured by Hitachi High-Tech Science) in accordance with JIS K 7375:2008 "Plastics - Measurement of Total Light Transmittance and Total Light Reflectance". In addition, when the light transmittance was 80% or more, it was evaluated as "0", and when it was less than 80%, it was evaluated as "△".

<Light resistance test> The light resistance test was performed about the optical film produced above. The light of a xenon lamp (60W/m ² ) was continuously irradiated on the prepared film for 100 hours, and the absorbance of the film before irradiation (0 hours) and after irradiation (100 hours) was measured with a spectrophotometer, according to the following formula ( 1) The residual ratio of the pigment was measured. Formula (1) Remaining rate of pigment (%)={(A ₁₀₀ )/(A ₀ )}×100 (however, A ₀ represents the absorbance before xenon lamp irradiation, and A ₁₀₀ represents the absorbance after xenon lamp irradiation) And, the so-called "Absorbance" refers to the absorbance at the maximum absorption wavelength of each compound. The higher the residual rate of the pigment, the more difficult the compound is to be decomposed by light, showing high light resistance. The light resistance was evaluated according to the following criteria.

A: The residual rate of pigment is more than 65% B: The residual rate of pigment is more than 40% and less than 65% C: The residual rate of pigment is more than 10% and less than 40% D: The residual rate of pigment is less than 10%

<Durability: Evaluation of External Leakage> After leaving each optical film in a high temperature and high humidity environment of 60°C and 90% RH for 1000 hours, the presence or absence of external leakage (crystal precipitation) on the surface of the optical film was visually observed, and the external leakage was performed according to the criteria described below. evaluation.

◎: No external leakage was observed on the surface of the optical film at all ○: Partial leakage on the surface of the optical film was slightly confirmed △: Slightly confirmed that the entire surface leaks on the surface of the optical film ×: A clear external leakage was observed on the entire surface of the optical film. The composition of the optical film and the above evaluation results are shown in Table III.

As can be seen from the results in Table III, the optical film of the present invention has excellent light transmittance, light resistance and durability when the pigment compound having the structure represented by the general formula (1) of the present invention is used.

[Example 2] <Production of Optical Film 201> 19.7 parts by mass of mixed urethane acrylate (UA-1100H manufactured by Shin-Nakamura Chemical Co., Ltd.), 0.1 part by mass of a photopolymerization initiator (IRGACURE 184 manufactured by BASF Corporation), denatured silicone (KF-351A manufactured by Shin-Etsu Chemical Co., Ltd.) ) 0.3 parts by mass, Emargen 404 (manufactured by Kao Chemical Co., Ltd.) 0.05 parts by mass, 39.5 parts by mass of propylene glycol monomethyl ether (PGME), 39.5 parts by mass of methyl acetate, 0.1 parts by mass of the exemplified dye compound 6, and carefully stirred to prepare a coating Use composition. The obtained coating composition was coated on a COP substrate with a wire bar to a thickness of 25 μm, dried, and UV cured to produce an optical film 201 having a functional layer (hard coating layer) with a thickness of 5 μm.

<Production of Optical Films 202~212> For the production of the optical film 201, the optical films 202 to 212 were produced in the same manner except that the exemplified dye compounds were changed to those described in Table IV. About the produced optical films 201-212, it carried out similarly to Example 1, and evaluated light resistance and durability. The results are shown in Table IV.

As can be seen from the results in Table IV, the optical film of the present invention has excellent light transmittance and light resistance as in Example 1 by using the compound having the structure represented by the general formula (1) of the present invention as the functional layer. and durability.

[Example 3] Using the optical films produced in Examples 1 and 2, production and evaluation of polarizing plates were carried out.

<Production of polarizing plate 301> (1) Production of polarizers A long polyvinyl alcohol film with a thickness of 60 μm was immersed in a dyeing bath (30° C.) prepared with iodine and potassium iodide while continuously conveying it through a guide roller, and then subjected to dyeing treatment and 2.5 times stretching treatment, and then added boric acid and potassium iodide. In the acid bath (60°C), a total of 5 times the stretching treatment and crosslinking treatment were applied, and the obtained iodine-PVA-based polarizer with a thickness of 12 μm was dried in a dryer at 50°C for 30 minutes to obtain moisture. Polarized photons with a rate of 4.9%.

(2) Preparation of UV-curable adhesive The following components were mixed to obtain a liquid ultraviolet curable adhesive (UV adhesive). 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate: 40 parts by mass Bisphenol A epoxy resin: 60 parts by mass Diphenyl[4-(phenylthio)phenyl]sulfonium hexafluoroantimonate (cationic polymerization initiator): 4 parts by mass

(3) Production of polarizing plate After corona treatment was applied to the bonding surface of the optical film 101 , the UV curable adhesive prepared above was applied to a dry thickness of 3 μm by a coating device equipped with a chambered doctor. Further, the bonding surface of Konica Minolta Tuck KC4CT (thickness 40 μm, manufactured by Konica Minolta Corporation) as the opposing film was corona-treated in the same manner, and then the above-mentioned ultraviolet curable adhesive was applied to a dry thickness of 3 μm.

Immediately thereafter, the optical film 101 is attached to one side of the above-mentioned polarizer, and the TAC film of the opposite side is attached to each other in a roll-to-roll manner by means of a UV-curable adhesive. . The bonding proceeds until the retardation axis (or advancing axis) of the optical film 101 and the absorption axis (or transmission axis) of the polarizer are aligned (the angle formed between the in-plane retardation axis of the optical film 101 and the absorption axis of the polarizer is 45°). After that, while conveying the bonded product at a linear speed of 20 m/min, the optical film 106 side was irradiated with ultraviolet rays by a metal halide lamp so ^{that the integrated light amount in a wavelength of 280 to 320 nm would be 320 mJ/cm 2 .} In this way, the polarizing plate 301 is obtained after curing the ultraviolet curing adhesive. In addition, since the production of the polarizing plate 301 is carried out in a roll-to-roll method, the long-length polarizing plate is finally cut along the width direction, and the sheet-shaped polarizing plate 301 is produced.

The prepared polarizing plate 301 is attached to the position where the polarizing plate on the identification side of the organic EL image display device is peeled off, and the optical film 101 side of the above-mentioned polarizing plate is attached to become the organic EL element side, and an organic EL image is produced. Display device 301 .

<Production of polarizing plate and organic EL image display devices 302 to 319 > For the production of the polarizing plate 301 , the polarizing plates 302 to 319 and the organic EL image display devices 302 to 319 were produced in the same manner except that the optical film 101 was changed to what is described in Table V. For the polarizing plates 301 to 319 and the organic EL image display devices 301 to 319 produced, the same evaluation as in Example 1 and the evaluation of the following light leakage were performed, and the results are shown in Table V.

＜Light Leak Evaluation＞ The organic EL image display device fabricated above was stored in an environment of 60°C･90%RH for 500 hours, and then left at normal temperature and humidity (23°C･55%RH) for 24 hours. The occurrence of display unevenness due to screen light leakage during black display was visually observed and evaluated based on the following criteria. ○: Display unevenness due to light leakage does not occur △: Slightly confirmed occurrence of display unevenness due to light leakage ×: Display unevenness due to light leakage is clearly generated

As can be seen from Table V, by using the optical film of the present invention, a polarizing plate and an organic EL image display device which are excellent in light resistance and durability and have no light leakage can be obtained. [Industrial availability]

The optical film of the present invention not only has high transparency and prevents light leakage, but also has excellent light resistance and durability under more severe environmental conditions, so it can be suitably used for polarizing plates or organic electroluminescence image display devices .

100: polarizer 101: Polarized Photons 102: Optical Film 103: Opposite film 104: Next layer 200: Organic EL Image Display Device 300: Organic EL element 301: Substrate 302: Metal Electrode 303: Light Emitting Layer 304: Transparent electrode 305: Sealing layer 400: Next layer

FIG. 1 is a cross-sectional view showing the configuration of the polarizing plate 100 . [ FIG. 2 ] An exploded cross-sectional view showing the organic EL image display device 200 .

100: polarizer

101: Polarized Photons

102: Optical Film

103: Opposite film

104: Next layer

Claims (12)

An optical film, which is an optical film containing a thermoplastic resin, characterized by containing a compound having a structure represented by the following general formula (1);

(In the formula, Z represents a heteroaryl group having two or more heteroatoms, and may have a substituent). The optical film of claim 1, wherein the aforementioned Z is any one of the groups shown in the following structural formula;

(The group represented by the above structural formula may further have a substituent; and R represents a substituent). The optical film of claim 2, wherein the aforementioned Z is any one of the groups shown in the following structural formula;

(The group represented by the above structural formula may further have a substituent; and R represents a substituent). The optical film according to any one of claim 1 to claim 3, wherein the energy level of the highest occupied molecular orbital of the compound having the structure represented by the general formula (1) is -5.85 below ev. The optical film according to any one of claim 1 to claim 4, wherein the thermoplastic resin is a cyclic olefin resin or an acrylic resin. The optical film according to claim 5, wherein the cyclic olefin-based resin has a polar group. The optical film according to any one of claim 1 to claim 6, wherein the compound having the structure represented by the general formula (1) is contained in a range of 0.01 to 20 mass % relative to the thermoplastic resin. The optical film according to any one of claim 1 to claim 7, further comprising a functional layer. The optical film according to claim 8, wherein the functional layer contains a compound having the structure represented by the general formula (1). The optical film according to any one of claim 1 to claim 9, wherein the aforementioned optical film is a λ/4 retardation film. A polarizing plate is characterized by having the optical film according to any one of claim 1 to claim 10. An organic electroluminescence image display device, characterized by having the optical film as claimed in any one of claim 1 to claim 10 or the polarizing plate as claimed in claim 11.

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