TW202214443A - Retardation film and method for manufacturing same - Google Patents

Abstract

Provided are: a retardation film that has little change in phase difference in heated environments, humidified environments, and after contact with solvents, and that also has excellent solvent resistance; and a method for manufacturing the retardation film. The retardation film according to an embodiment of the present invention comprises a first cured layer, a retardation layer, and a second cured layer, in that order. The retardation layer is formed from a stretched resin film, and the stretched resin film includes a resin containing at least one binding group chosen from carbonate bonds and ester bonds. In the first cured layer and the second cured layer, a cross-linking agent that has a carbon-carbon double bond and the resin included in the stretched resin film are cross-linked via the carbon-carbon double bond.

Description

Phase difference film and method for producing the same

The present invention relates to a retardation film and a manufacturing method thereof.

In recent years, with the popularity of thin displays, the industry has proposed a display equipped with an organic EL (Electroluminescence, electroluminescence) panel. However, the organic EL panel has a metal layer with high reflectivity, which is prone to problems such as external light reflection and/or background reflection. In this regard, it is known to prevent such problems by using a circular polarizer with a λ/4 plate on the viewing side. The retardation film used for the above-mentioned circularly polarizing plate has a problem that the retardation changes in a heating environment and/or a humidified environment. Furthermore, this retardation film has a problem that the retardation changes even when it comes into contact with a solvent. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2006-171235

[Problems to be Solved by Invention]

The present invention is accomplished in order to solve the above-mentioned previous problems, and its main purpose is to provide a retardation film and a simple manufacturing method thereof, the retardation film has a small change in retardation even in a heating environment and a humidified environment, and furthermore The phase difference change is small even when it comes into contact with a solvent. [Technical means to solve problems]

於一實施方式中，上述樹脂包含下式所表示之結構單元。 [化2]

於一實施方式中，上述相位差膜滿足Re(450)＜Re(550)＜Re(650)之關係。 於一實施方式中，上述相位差膜滿足0.7＜Re(450)/Re(550)＜1.0之關係。 於一實施方式中，上述相位差膜之Re(550)為100 nm～180 nm或220 nm～330 nm。 於提供圓偏光板之態樣中，該圓偏光板具備上述相位差膜及偏光元件。 根據本發明之另一態樣，提供一種圖像顯示裝置。該圖像顯示裝置具備上述相位差膜。於另一實施方式中，該圖像顯示裝置具備上述圓偏光板。 根據本發明之另一態樣，提供一種上述相位差膜之製造方法。該製造方法包括使用自由基產生劑使上述樹脂與上述交聯劑經由上述交聯劑之上述碳-碳雙鍵交聯之步驟。 於一實施方式中，上述自由基產生劑為奪氫型光自由基產生劑。 於一實施方式中，上述自由基產生劑為奪氫型熱自由基產生劑。 [發明之效果] A retardation film according to an embodiment of the present invention includes a first cured layer, a retardation layer, and a second cured layer in this order, and the retardation layer is formed of a stretched resin film including a carbonic acid ester bond and an ester bond selected from the group consisting of In the resin of at least one bonding group, in the first hardened layer and the second hardened layer, a crosslinking agent having a carbon-carbon double bond and the resin are crosslinked through the carbon-carbon double bond. In one embodiment, the above-mentioned resin includes a structural unit represented by the following formula. [hua 1]

In one embodiment, the above-mentioned resin includes a structural unit represented by the following formula. [hua 2]

In one embodiment, the retardation film satisfies the relationship of Re(450)<Re(550)<Re(650). In one embodiment, the retardation film satisfies the relationship of 0.7<Re(450)/Re(550)<1.0. In one embodiment, Re(550) of the retardation film is 100 nm to 180 nm or 220 nm to 330 nm. In an aspect in which a circularly polarizing plate is provided, the circularly polarizing plate includes the above retardation film and a polarizing element. According to another aspect of the present invention, an image display device is provided. This image display device includes the above retardation film. In another embodiment, the image display device includes the aforementioned circular polarizer. According to another aspect of the present invention, a method for manufacturing the above retardation film is provided. The production method includes the step of crosslinking the above-mentioned resin and the above-mentioned cross-linking agent via the above-mentioned carbon-carbon double bond of the above-mentioned cross-linking agent using a radical generator. In one embodiment, the radical generator is a hydrogen abstraction type photoradical generator. In one embodiment, the radical generator is a hydrogen abstraction type thermal radical generator. [Effect of invention]

The retardation film which concerns on embodiment of this invention has a 1st hardened layer, a retardation layer, and a 2nd hardened layer in this order. The retardation layer is formed of a stretched resin film containing a resin having at least one bonding group selected from a carbonate bond and an ester bond. Furthermore, in the 1st hardened layer and the 2nd hardened layer, the crosslinking agent which has a carbon-carbon double bond and the resin contained in the stretched resin film are cross-linked via the carbon-carbon double bond. In the retardation film according to the embodiment of the present invention, the retardation layer, the first hardened layer and the second hardened layer are cross-linked as described above, so that even in a heating environment and a humidified environment, the phase difference change is relatively high. A retardation film that is small and has a small retardation change even when it comes into contact with a solvent.

Hereinafter, representative embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

(Definition of Terms and Symbols) Definitions of terms and symbols in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction of the largest refractive index in the plane (ie, the direction of the slow axis), "ny" is the refractive index in the direction orthogonal to the slow axis in the plane (ie the direction of the advance axis), "nz" " is the refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re(λ)" is the in-plane retardation measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured with light having a wavelength of 550 nm at 23°C. When the thickness of the layer (film) is d (nm), Re(λ) is obtained by the formula: Re(λ)=(nx−ny)×d. (3) Angle In this specification, when referring to an angle, the angle includes both a clockwise direction and a counterclockwise direction with respect to the reference direction. Thus, for example, "45°" means ±45°.

A. Overall composition of retardation film FIG. 1 is a schematic cross-sectional view of a retardation film according to an embodiment of the present invention. The retardation film 100 of the illustrated example has the first cured layer 10 , the retardation layer 20 , and the second cured layer 30 in this order. The retardation layer is formed of a stretched resin film containing a resin having at least one bonding group selected from a carbonate bond and an ester bond. In the first hardened layer and the second hardened layer, the crosslinking agent having a carbon-carbon double bond and the resin contained in the stretched resin film are crosslinked through the carbon-carbon double bond. As a result, the first hardened layer and the second hardened layer can be formed in the vicinity of the surfaces on both sides of the retardation layer. More specifically, in the retardation film, it is presumed that the central part in the thickness direction of the retardation layer contains the above-mentioned resin which is not cross-linked or has a small degree of cross-linking, and the above-mentioned resin in the vicinity of the surface is cross-linked, and as a result, the first cured layer and the second cured layer are formed. 2 hardened layers. That is, the first cured layer and the second cured layer are formed of the resin contained in the retardation layer. By having such a structure, the retardation film has the advantages that the change of the retardation in a heating environment, a humidified environment, and after contact with a solvent is small, and furthermore, it is excellent in solvent resistance. In addition, FIG. 1 is a schematic diagram, and for convenience of description, the interface of a 1st hardened layer, a stretched resin film, and a 2nd hardened layer is clearly shown. However, it is presumed that a clear interface does not actually exist, and the first cured layer, the stretched resin film, and the second cured layer may have a gradient structure.

The gel fraction of the retardation film is preferably 90% or more, more preferably 95% or more, and still more preferably 97% to 99%. It is presumed that such a gel fraction is achieved in order to substantially prevent the penetration of the solvent into the retardation layer by the first hardened layer and the second hardened layer. As described above, the thickness direction central portion of the retardation layer is presumed to be composed of the above-mentioned resin which is not cross-linked or has a small degree of cross-linking, but is not reflected in the gel fraction due to the first hardened layer and the second hardened layer. Furthermore, the gel fraction can be calculated from the weight of the sample before and after the immersion by immersing the sample made of the retardation film in a specific solvent (eg, toluene).

[化4]

In one embodiment, the above-mentioned crosslinking may be crosslinking of structural units derived from an isosorbide-based dihydroxy compound in the resin contained in the retardation layer. Furthermore, in one Embodiment, the said crosslinking can be in the 1st hardened layer and the 2nd hardened layer, through the carbon- Cross-linking of carbon bonds. For example, the structure of the reactant obtained by crosslinking the structural units derived from the isosorbide-based dihydroxy compound via the carbon-carbon double bond of the crosslinking agent is shown below. Furthermore, the structure of the crosslinking agent used for this crosslinking reaction is shown below. [hua 3]

[hua 4]

Such a cross-linked structure can be formed by performing a cross-linking treatment (by post-cross-linking) after producing the stretched resin film. In one embodiment, a polyethylene terephthalate (PET) film is roll-laminated on both sides of the stretched resin film through a reactive composition comprising a crosslinking agent and a free radical generator. The obtained laminate was subjected to a crosslinking reaction, and then the PET film was peeled off to form a first cured layer and a second cured layer on the surface of the stretched resin film (retardation layer) to obtain a retardation film according to an embodiment of the present invention. . In another embodiment, the surface of the stretched resin film is coated with a reactive composition comprising a cross-linking agent and a free radical generator (and optionally a diluting solvent), and after heat treatment as required, under a nitrogen atmosphere A hardened layer can be obtained by performing a crosslinking reaction (by heat or UV (ultraviolet) irradiation). By performing this operation on both sides of the stretched resin film, the first cured layer and the second cured layer are formed on the surface of the stretched resin film (retardation layer), thereby obtaining the retardation film according to the embodiment of the present invention. When forming such a crosslinked structure, the resin forming the stretched resin film does not need to contain a crosslinkable group. When a resin containing a crosslinkable group is used to manufacture a stretched resin film, problems such as gelation of the resin during manufacturing steps (eg, kneading, extrusion, and stretching) may arise. According to embodiment of this invention, the retardation film which has a 1st hardened layer and a 2nd hardened layer can be manufactured, without causing such a problem. Furthermore, after crosslinking according to the embodiment of the present invention, it can be used for the production of the retardation film of the embodiment of the present invention without changing the normal retardation film and the steps of producing the retardation film. The present invention has an excellent effect in this respect.

The retardation film (substantially the retardation layer) preferably satisfies the relationship of Re(450)<Re(550)<Re(650). Furthermore, the retardation film preferably satisfies the relationship of 0.7<Re(450)/Re(550)<1.0. That is, the retardation film exhibits inverse wavelength dispersion characteristics in which the retardation value increases according to the wavelength of the measurement light. With the retardation film having such characteristics, very excellent anti-reflection characteristics can be realized.

The Re(550) of the retardation film (substantially the retardation layer) is preferably 100 nm to 180 nm or 220 nm to 330 nm, more preferably 120 nm to 180 nm or 240 nm to 310 nm.

The thickness of the retardation film can be any appropriate thickness according to the required Re(550). The thickness of the retardation film is preferably 20 μm to 100 μm, more preferably 30 μm to 60 μm. This thickness represents the total thickness of the retardation layer, the first hardened layer, and the second hardened layer.

The internal haze of the retardation film (substantially a retardation layer) is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less. The lower limit of internal haze may be substantially 0%. If the internal haze is within such a range, the excellent transparency of the retardation film can be realized.

The photoelastic coefficient of the retardation film (substantially the retardation layer) is preferably 1×10 ^-12 (m ² /N)～40×10 ^-12 (m ² /N), more preferably 1×10 ^-12 (m ² /N) to 30×10 ^-12 (m ² /N), more preferably 1×10 ^-12 (m ² /N) to 20×10 ^-12 (m ² /N).

A-1. Retardation layer The retardation layer may be formed of a stretched resin film. The stretched resin film can be obtained by stretching the resin film. The resin film includes a resin having at least one bonding group among carbonate bonds and ester bonds. As this resin, polycarbonate-type resin, polyester carbonate-type resin, polyester-type resin, polyarylate-type resin, and acrylic resin are mentioned, for example. These resins may be used alone or in combination (eg, blending, copolymerization). Among them, polycarbonate-based resins or polyester carbonate-based resins (hereinafter sometimes simply referred to as polycarbonate-based resins) are suitably used.

As the above-mentioned polycarbonate-based resin, any appropriate polycarbonate-based resin can be used as long as the effects of the present invention can be obtained. For example, the polycarbonate-based resin preferably contains a structural unit derived from a perylene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit derived from the group consisting of alicyclic diol, alicyclic Structural unit of at least one dihydroxy compound in the group consisting of dimethanol, diethylene glycol, triethylene glycol or polyethylene glycol and alkylene glycol or spiro glycol. The polycarbonate-based resin preferably contains: a structural unit derived from a perylene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit and/or source derived from alicyclic dimethanol A structural unit derived from diethylene glycol, triethylene glycol or polyethylene glycol; further preferably, it comprises: a structural unit derived from a perylene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and structural units derived from diethylene glycol, triethylene glycol or polyethylene glycol. The polycarbonate-based resin may also contain other structural units derived from dihydroxy compounds as required. Further, details of the polycarbonate resin suitable for use in the present invention are described in, for example, Japanese Patent Laid-Open No. 2014-10291, Japanese Patent Laid-Open No. 2014-26266, Japanese Patent Laid-Open No. 2015-212816, In Japanese Patent Laid-Open No. 2015-212817 and Japanese Patent Laid-Open No. 2015-212818, the descriptions are incorporated herein by reference.

As the structural unit derived from the above-mentioned perylene-based dihydroxy compound, the structural unit represented by the following formula may, for example, be mentioned. This building block is sometimes referred to as an oligomeric fluoride building block.

[hua 5]

[hua 6]

In the above general formula (1) and the above general formula (2), R ¹ to R ³ are each independently a direct bond, an optionally substituted alkylene group having 1 to 4 carbon atoms, and R ⁴ to R ⁹ are each independently It is a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 4 to 10 carbon atoms, an optionally substituted aryl group having 1 to 10 carbon atoms, and an optionally substituted group alkoxy group with 1 to 10 carbon atoms, aryloxy group with 1 to 10 carbon atoms which may have substituents, aryloxy groups with 1 to 10 carbon atoms which may have substituents, amine groups which may have substituents, A vinyl group having 1 to 10 carbon atoms, an ethynyl group having 1 to 10 carbon atoms that may have a substituent, a sulfur atom having a substituent, a silicon atom having a substituent, a halogen atom, a nitro group or a cyano group. Among them, at least two adjacent groups of R ⁴ to R ⁹ may be bonded to each other to form a ring. Moreover, the two R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ contained in the general formula (1) may be the same or different from each other. Similarly, the two R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ included in the general formula (2) may be the same or different from each other.

In R ¹ and R ² , as "the alkylene group having 1 to 4 carbon atoms which may have a substituent", for example, the following alkylene groups can be used: methylene group, ethylidene group, n-propylidene group, n-butylene group, etc. Linear alkylene; methylmethylene, dimethylmethylene, ethylmethylene, propylmethylene, (1-methylethyl)methylene, 1-methylethylidene base, 2-methylethylidene, 1-ethylidene, 2-ethylethylidene, 1-methylpropylidene, 2-methylpropylidene, 1,1-dimethylethylidene , 2,2-dimethyl propylidene, 3-methylpropylidene and other branched alkyl groups. Here, the positions of the branches in R ¹ and R ² are indicated by the numbers assigned so that the carbon on the side of the perylene ring becomes the 1-position.

The selection of R ¹ and R ² has an important influence on the development of inverse wavelength dispersion in particular. The above-mentioned resin exhibits the strongest inverse wavelength dispersion in a state in which the perylene rings are aligned perpendicularly to the main chain direction (extending direction). In order to make the alignment state of the perylene ring close to the above state and to exhibit strong inverse wavelength dispersion, it is preferable to use R ¹ and R ² having 2 to 3 carbon atoms on the main chain of the alkylene group. When the number of carbon atoms is 1, inverse wavelength dispersion may not be exhibited unexpectedly. The reason for this is considered to be that the alignment of the perylene ring is fixed in a direction not perpendicular to the main chain direction due to the steric hindrance of the carbonate group and/or the ester group as the linking group of the oligomerized perylene structural unit. On the other hand, when the number of carbon atoms is too large, since the fixation of the orientation of the pyrene ring becomes weak, there is a possibility that the inverse wavelength dispersion property becomes weak. Moreover, the heat resistance of resin also falls.

As shown in the above general formula (1) and general formula (2), one end of the alkylene group in R ¹ and R ² is bonded to the perylene ring, and the other end is bonded to the oxygen atom or carbonyl carbon contained in the linking group. the key. From the viewpoint of thermal stability, heat resistance, and reverse wavelength dispersion, it is preferable that the other end of the alkylene group is bonded to the carbonyl carbon.

Moreover, it is preferable to use the same alkylene group for R ¹ and R ² from the viewpoint of easy production.

In R ³ , as the "optionally substituted alkylene group having 1 to 4 carbon atoms", for example, the following alkylene groups can be used: straight chain extensions such as methylene group, ethylidene group, n-propylidene group, n-butylene group, etc. Alkyl; methylmethylene, dimethylmethylene, ethylmethylene, propylmethylene, (1-methylethyl)methylene, 1-methylethylidene, 2- Methylidene, 1-ethylidene, 2-ethylidene, 1-methylpropylidene, 2-methylpropylidene, 1,1-dimethylethylidene, 2,2 - Dimethyl propylidene, 3-methylpropylidene and other branched alkylene groups.

R ³ preferably has 1 to 2 carbon atoms in the main chain of the alkylene group, and particularly preferably has 1 carbon number. When R ³ having too many carbon atoms in the main chain is used, as with R ¹ and R ² , the immobilization of the perylene ring becomes weak, resulting in a decrease in inverse wavelength dispersion, an increase in the photoelastic coefficient, and a decrease in heat resistance, etc. Danger. On the other hand, although the optical properties and/or heat resistance are good when the number of carbon atoms in the main chain is small, the thermal stability is deteriorated when the 9-position of the two perylene rings is connected by a direct bond.

In R ¹ to R ³ , as the substituent that the alkylene group may have, the substituents exemplified below may be used, and the substituents other than these may be used: a group selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Halogen atom; alkoxy groups with 1 to 10 carbon atoms such as methoxy and ethoxy; acyl groups with 1 to 10 carbon atoms such as acetyl and benzyl groups; acetamido, benzylamino, etc. C 1-10 amido group; nitro group; cyano group; 1-3 hydrogens may be substituted by the above-mentioned halogen atom, the above-mentioned alkoxy group, the above-mentioned amido group, the above-mentioned amido group, the above-mentioned nitro group, the above-mentioned cyano group, etc. An aryl group having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group.

The number of the above-mentioned substituents is not particularly limited, but is preferably 1 to 3. When there are two or more substituents, the kind of the substituents may be the same or different. When the number of the substituents is too large, the reaction may be inhibited or thermal decomposition may occur during polymerization. Moreover, it is preferable that R ¹ to R ³ are not substituted from the viewpoint of industrially economical production.

Among R ⁴ to R ⁹ , as the "optionally substituted alkyl group having 1 to 10 carbon atoms", for example, the following alkyl groups can be used: methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl Alkyl, n-decyl and other straight-chain alkyl groups; isopropyl, 2-methylpropyl, 2,2-dimethylpropyl, 2-ethylhexyl and other branched alkyl groups; cyclopropyl, Cyclic alkyl groups such as cyclopentyl, cyclohexyl, and cyclooctyl.

The number of carbon atoms in the alkyl group is preferably 4 or less, more preferably 2 or less. If the carbon number of the above-mentioned alkyl group is within this range, the steric hindrance between the perylene rings is unlikely to occur, and the desired optical properties derived from the perylene rings tend to be obtained.

As the substituent which the above-mentioned alkyl group may have, the following exemplified substituents may be used, and substituents other than these may be used: a halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a methoxy group, an ethyl group Alkoxy with 1 to 10 carbons such as oxy; acyl with 1 to 10 carbons such as acetyl and benzyl; nitro group; cyano group; phenyl group, naphthyl group, etc., which can be substituted with 1 to 3 hydrogen atoms by the above-mentioned halogen atom, the above-mentioned alkoxy group, the above-mentioned amide group, the above-mentioned amide group, the above-mentioned nitro group, the above-mentioned cyano group, etc. Aryl having 6 to 10 carbon atoms.

The number of the above-mentioned substituents is not particularly limited, but is preferably 1 to 3. When there are two or more substituents, the kind of the substituents may be the same or different. When the number of such substituents is too large, the reaction may be inhibited or thermal decomposition may occur during polymerization. Moreover, it is preferable that R ⁴ to R ⁹ are unsubstituted from the viewpoint of industrially economical production.

As a specific example of the said alkyl group, a trifluoromethyl group, a benzyl group, a 4-methoxybenzyl group, a methoxymethyl group, etc. are mentioned.

In addition, in R ⁴ to R ⁹ , as the "aryl group having 4 to 10 carbon atoms which may have a substituent", for example, the following aryl groups can be used: aryl groups such as phenyl, 1-naphthyl, and 2-naphthyl; 2-pyridyl, 2-thienyl, 2-furyl and other heteroaryl groups.

The number of carbon atoms in the aryl group is preferably 8 or less, more preferably 7 or less. If the carbon number of the above-mentioned aryl group is within this range, the steric hindrance between the perylene rings is unlikely to occur, and the desired optical properties derived from the perylene rings tend to be obtained.

In R ⁴ to R ⁹ , as the substituent which the above-mentioned aryl group may have, the following exemplified substituents may be used, and substituents other than these may be used: a group selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Halogen atom; C1-10 alkyl groups such as methyl, ethyl and isopropyl; alkoxy groups such as methoxy, ethoxy and other C1-10 carbons; acetyl, benzyl and other carbons Acetyl group of 1 to 10; acylamino group of 1 to 10 carbon atoms such as acetamido group and benzylamino group; nitro group; cyano group. The number of the above-mentioned substituents is not particularly limited, but is preferably 1 to 3. When there are two or more substituents, the kind of the substituents may be the same or different. Moreover, it is preferable that R ⁴ to R ⁹ are not substituted from the viewpoint of industrially economical production.

Specific examples of the above-mentioned aryl group include 2-methylphenyl, 4-methylphenyl, 3,5-dimethylphenyl, 4-benzylphenyl, and 4-methoxy Phenyl, 4-nitrophenyl, 4-cyanophenyl, 3-trifluoromethylphenyl, 3,4-dimethoxyphenyl, 3,4-methylenedioxyphenyl, 2,3,4,5,6-pentafluorophenyl, 4-methylfuranyl, etc.

In addition, among R ⁴ to R ⁹ , as "the aryl group having 1 to 10 carbon atoms which may have a substituent", for example, the following aryl groups can be used: methionyl, acetyl, propionyl, and 2-methyl aliphatic aryl groups such as propionyl, 2,2-dimethylpropionyl, 2-ethylhexyl; benzyl, 1-naphthylcarbonyl, 2-naphthylcarbonyl, 2-furylcarbonyl and other aromatic acyl groups.

The number of carbon atoms in the acyl group is preferably 4 or less, more preferably 2 or less. If the carbon number of the above-mentioned acyl group is within this range, the steric hindrance of the perylene rings is less likely to occur, and the desired optical properties derived from the perylene rings tend to be obtained.

As the substituent which the above-mentioned acyl group may have, the following exemplified substituents may be used, and substituents other than these may be used: a halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a methyl group, an ethyl group , Isopropyl and other alkyl groups with carbon number 1 to 10; methoxy, ethoxy and other alkoxy groups with carbon number 1 to 10; Amine group; nitro group; cyano group; acyl group having 1 to 10 carbon atoms such as the above halogen atom, the above alkoxy group, acetyl group, benzyl group, the above amide group, the above nitro group, the above cyano group Aryl having 6 to 10 carbon atoms such as phenyl, naphthyl and other substituted 1 to 3 hydrogen atoms.

The number of the above-mentioned substituents is not particularly limited, but is preferably 1 to 3. When there are two or more substituents, the kind of the substituents may be the same or different. Moreover, it is preferable that R ⁴ to R ⁹ are not substituted from the viewpoint of industrially economical production.

As a specific example of the said acyl group, a chloroacetyl group, a trifluoroacetyl group, a methoxyacetyl group, a phenoxyacetyl group, a 4-methoxybenzyl group, and a 4-nitro group may be mentioned. benzyl, 4-cyanobenzyl, 4-trifluoromethylbenzyl and the like.

In addition, in R ⁴ to R ⁹ , as "the optionally substituted alkoxy group or aryloxy group having 1 to 10 carbon atoms", for example, the following alkoxy groups and aryloxy groups can be used: methoxy, ethoxy alkoxy group, isopropoxy group, tert-butoxy group, trifluoromethoxy group, phenoxy group and the like.

The number of carbon atoms in the alkoxy group and the aryloxy group is preferably 4 or less, more preferably 2 or less. If the carbon numbers of the above-mentioned alkoxy group and the above-mentioned aryloxy group are within this range, steric hindrance between the perylene rings is unlikely to occur, and the desired optical properties derived from the perylene rings tend to be obtained.

As the substituent which the above-mentioned alkoxy group and the above-mentioned aryloxy group may have, the following exemplified substituents may be used, and substituents other than these may be used: a halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom ; Methyl, ethyl, isopropyl and other alkyl groups with carbon number 1 to 10; methoxy, ethoxy and other alkoxy groups with carbon number 1 to 10; acetamide, benzamide and other carbons The amide group of 1 to 10; nitro group; An aryl group having 6 to 10 carbon atoms such as a phenyl group in which 1 to 3 hydrogen atoms are substituted by a nitro group, the above-mentioned cyano group, and a naphthyl group.

The number of the above-mentioned substituents is not particularly limited, but is preferably 1 to 3. When there are two or more substituents, the kind of the substituents may be the same or different. Moreover, it is preferable that R ⁴ to R ⁹ are not substituted from the viewpoint of industrially economical production.

Specific examples of the above-mentioned alkoxy group and the above-mentioned aryloxy group include chloromethyl, bromomethyl, 2-bromoethyl, trifluoromethyl, methoxymethyl, and methoxyethoxymethyl. base, 3-chlorophenoxy, 3-bromophenoxy, 4-chlorophenoxy, 3-chlorophenoxy, 4-chlorophenoxy, 3-bromophenoxy, 4-bromophenoxy , 4-methoxyphenoxy, etc.

In addition, among R ⁴ to R ⁹ , as "the aryloxy group having 1 to 10 carbon atoms which may have a substituent", for example, the following aryloxy groups can be used: methoxyl group, acetyloxyl group, propionyloxyl group , aliphatic aryloxy groups such as butyryloxy, acryloxy, methacryloyloxy; aromatic aryloxy such as benzyloxy.

The number of carbon atoms in the above-mentioned oxyalkyl group is preferably 4 or less, more preferably 2 or less. If the carbon number of the above-mentioned aryloxy group is within this range, the steric hindrance between the perylene rings is unlikely to occur, and the desired optical properties derived from the perylene rings tend to be obtained.

As the substituent which the above-mentioned alkoxyl group may have, the following exemplified substituents may be used, and substituents other than these may be used: a halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a methyl group, a ethyl group Alkyl groups with 1 to 10 carbon atoms such as methoxy and isopropyl; alkoxy groups with 1 to 10 carbon atoms such as methoxy and ethoxy; amide group; nitro group; cyano group; amide group with 1 to 10 carbon atoms such as the above halogen atom, the above alkoxy group, acetyl group, benzyl group, the above amide group, the above nitro group, the above cyano group phenyl, naphthyl and other aryl groups having 6 to 10 carbon atoms in which 1 to 3 hydrogen atoms are substituted.

The number of the above-mentioned substituents is not particularly limited, but is preferably 1 to 3. When there are two or more substituents, the kind of the substituents may be the same or different. Moreover, it is preferable that R ⁴ to R ⁹ are not substituted from the viewpoint of industrially economical production.

Specific examples of the above acyloxy group include chloroacetoxyl, trifluoroacetoxyl, methoxyacetoxyl, phenoxyacetyloxy, and 4-methoxybenzyloxy oxy, 4-nitrobenzyloxy, 4-cyanobenzyloxy, 4-trifluoromethylbenzyloxy and the like.

In addition, in R ⁴ to R ⁹ , as a specific structure of the "amino group which may have a substituent", for example, the following amino groups can be used, and other amino groups can also be used: amino group; N-methylamino group , N,N-dimethylamino, N-ethylamino, N,N-diethylamino, N,N-methylethylamino, N-propylamino, N,N- Dipropylamine, N-isopropylamine, N,N-diisopropylamine and other aliphatic amines; N-phenylamine, N,N-diphenylamine and other aromatic amines Carboxylamino, acetamide, decylamino, benzylamino, chloroacetamide and other amides; benzyloxycarbonylamino, tert-butoxycarbonylamino and other alkanes Oxycarbonylamino.

As the above-mentioned amino group, it is preferable to use N,N-dimethylamino, N-ethylamino or N,N-dimethylamino, N-ethylamino or N,N- A diethylamine group, more preferably an N,N-dimethylamine group, is used.

In addition, in R ⁴ to R ⁹ , as "the vinyl group or ethynyl group having 1 to 10 carbon atoms which may have a substituent", for example, the following vinyl group and ethynyl group can be used, and a vinyl group other than these can also be used. : Vinyl, 2-methylvinyl, 2,2-dimethylvinyl, 2-phenylvinyl, 2-acetylvinyl, ethynyl, methylethynyl, tert-butylethynyl , Phenylethynyl, Acetylethynyl, Trimethylsilylethynyl.

The number of carbon atoms in the vinyl group and the ethynyl group is preferably 4 or less. When the carbon numbers of the vinyl group and the ethynyl group are within this range, steric hindrance between the perylene rings is unlikely to occur, and the desired optical properties derived from the perylene rings tend to be obtained. In addition, it is easy to obtain stronger inverse wavelength dispersion properties by increasing the length of the conjugated system of the pyrene ring.

In addition, in R ⁴ to R ⁹ , as the "sulfur atom having a substituent", for example, the following sulfur-containing groups can be used, and other sulfur-containing groups can also be used: sulfo group; methylsulfonyl group, ethyl group Sulfonyl, propylsulfonyl, isopropylsulfonyl and other alkylsulfonyl; phenylsulfonyl, p-tolylsulfonyl and other arylsulfonyl; methylsulfinyl, ethylsulfonyl Alkylsulfinyl such as sulfosulfinyl, propylsulfinyl, isopropylsulfinyl; arylsulfinyl such as phenylsulfinyl, p-tolysulfinyl; Methylthio, ethylthio and other alkylthio groups; phenylthio, p-toluenethio and other arylthio groups; methoxysulfonyl, ethoxysulfonyl and other alkoxysulfonyl groups; phenoxysulfonyl Aryloxysulfonyl group such as acyl group; aminosulfonyl group; N-methylaminosulfonyl group, N-ethylaminosulfonyl group, N-tert-butylaminosulfonyl group, N, N-dimethylaminosulfonyl, N,N-diethylaminosulfonyl and other alkylsulfonyl; N-phenylaminosulfonyl, N,N-diphenylaminosulfonyl Arylaminosulfonyl such as acyl group. Furthermore, the sulfo group may form salts with lithium, sodium, potassium, magnesium, ammonium, and the like.

Among the above-mentioned sulfur-containing groups, it is preferred to use methylsulfinyl, ethylsulfinyl or phenylsulfinyl, which do not have protons with higher acidity, have a smaller molecular weight and can increase the ratio of sulfinyl, more preferably For the use of methylsulfinyl.

In addition, in R ⁴ to R ⁹ , as the "silicon atom having a substituent", for example, the following silyl groups can be used: trimethylsilyl groups such as trimethylsilyl groups, triethylsilyl groups, etc.; trimethoxysilyl groups , Triethoxysilyl and other trialkoxysilyl groups. Among them, a trialkylsilyl group which can be handled stably is preferable.

In addition, among R ⁴ to R ⁹ , as the "halogen atom", a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom can be used. Among them, it is preferable to use a fluorine atom, a chlorine atom or a bromine atom which is relatively easy to introduce and has electron-withdrawing properties and thus tends to increase the reactivity of the 9-position, more preferably a chlorine atom or a bromine atom.

As a structural unit derived from the said isosorbide type dihydroxy compound, the structural unit represented by the following formula is mentioned. [hua 7]

As a dihydroxy compound into which the structural unit represented by the said general formula (3) can be introduce|transduced, isosorbide (ISB), anhydromannitol, and isoiditol in a stereoisomer relationship can be mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more types. Among them, from the viewpoint of acquisition and polymerization reactivity, it is most preferable to use ISB.

The structural unit represented by the general formula (3) is preferably contained in the resin in an amount of 5 mass % or more and 70 mass % or less, more preferably 10 mass % or more and 65 mass % or less, particularly preferably 20 mass % or more. 60 mass % or less. When there is too little content of the structural unit represented by the said general formula (3), there exists a possibility that heat resistance may become inadequate. On the other hand, when the content of the structural unit represented by the above-mentioned general formula (3) is too large, the heat resistance will be too high, and the mechanical properties and/or melt processability will be deteriorated.

As a structural unit derived from diethylene glycol, triethylene glycol, or polyethylene glycol, the structural unit represented by following general formula (4)-(8) which does not contain an aromatic component is mentioned.

[hua 8]

In the above general formula (4), R ¹⁰ represents an optionally substituted alkylene group having 2 to 20 carbon atoms.

As the dihydroxy compound into which the structural unit of the general formula (4) can be introduced, for example, the following dihydroxy compounds can be used: ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1 ,3-butanediol, 1,2-butanediol, 1,5-heptanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,12 - Dihydroxy compounds of linear aliphatic hydrocarbons such as dodecanediol; dihydroxy compounds of branched aliphatic hydrocarbons such as neopentyl glycol and hexanediol.

[Chemical 9]

In the above general formula (5), R ¹¹ represents an optionally substituted cycloextended alkyl group having 4 to 20 carbon atoms.

As the dihydroxy compound into which the structural unit of the general formula (5) can be introduced, for example, the following dihydroxy compounds can be used: 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol Dihydroxy compounds of secondary alcohols and tertiary alcohols as alicyclic hydrocarbons exemplified by alcohols, hydrogenated bisphenol A, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and the like.

[Chemical 10]

In the above general formula (6), R ¹² represents an optionally substituted cycloextended alkyl group having 4 to 20 carbon atoms.

As the dihydroxy compound into which the structural unit of the general formula (6) can be introduced, for example, the following dihydroxy compounds can be used: 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol Hexane dimethanol, tricyclodecane dimethanol, pentacyclopentadecan dimethanol, 2,6-decahydronaphthalene dimethanol, 1,5-decahydronaphthalene dimethanol, 2,3-decahydronaphthalene dimethanol, Among the alicyclic hydrocarbons exemplified as dihydroxy compounds derived from terpene compounds, such as 2,3-noranadimethanol, 2,5-noranadimethanol, 1,3-adamantanedimethanol, limonene, etc. Dihydroxy compounds of primary alcohols.

[Chemical 11]

In the above general formula (7), R ¹³ represents an optionally substituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 1 to 40. Two or more R ¹³ may be the same or different from each other.

As the dihydroxy compound into which the structural unit of the general formula (7) can be introduced, for example, the following dihydroxy compounds can be used: diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, etc. Alkyl glycols.

[Chemical 12]

In the above general formula (8), R ¹⁴ represents a group having an acetal ring having 2 to 20 carbon atoms which may have a substituent.

As the dihydroxy compound into which the structural unit of the general formula (8) can be introduced, for example, spirodiols represented by the following structural formula (14) or diethylene glycol represented by the following structural formula (15) can be used. .

[Chemical 13]

[Chemical 14]

Details of the polycarbonate resin are described in, for example, Japanese Patent Laid-Open No. 2015-212816, Japanese Patent Laid-Open No. 2010-134232, and Japanese Patent Laid-Open No. 2020-064298. The description of this patent document is incorporated in this specification as a reference.

A-2. The first hardened layer and the second hardened layer As described above, the first cured layer and the second cured layer can be formed by crosslinking the resin and the crosslinking agent contained in the retardation layer. Therefore, the 1st hardened layer and the 2nd hardened layer can be comprised substantially from the said resin crosslinked by a crosslinking agent. Since the retardation film according to the embodiment of the present invention has the first hardened layer and the second hardened layer on both sides of the retardation layer, the retardation changes in a heating environment, in a humidified environment and after contact with a solvent are small, and furthermore, it is resistant to solvents. Sex is also excellent.

As this crosslinking agent, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2-ethyl-2-butylpropanediol di(meth)acrylate, bisphenol A di(meth)acrylate (Meth)acrylate, Bisphenol A ethylene oxide adduct di(meth)acrylate, Bisphenol A propylene oxide adduct di(meth)acrylate, Bisphenol A diglycidyl ether di (Meth)acrylate, Neopentyl glycol di(meth)acrylate, Tricyclodecane dimethanol di(meth)acrylate, Diethylene glycol di(meth)acrylate, Polyethylene glycol Di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate , Pentaerythritol tri(meth)acrylate, Pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, EO modified diglycerol tetra(meth)acrylate Ester of (meth)acrylic acid and polyhydric alcohols such as esters; 9,9-bis[4-(2-(meth)acrylooxyethoxy)phenyl]phenyl]. These can be used individually by 1 type, or can be used as a mixture of 2 or more types. Among them, tricyclodecane dimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and 1,6-hexanediol di(meth)acrylate are particularly preferred. The cross-linking agent can be appropriately selected according to the swellability of the stretched resin film subjected to the cross-linking treatment.

The thicknesses of the first hardened layer and the second hardened layer are preferably 0.2 μm to 10.0 μm, and more preferably 0.5 μm to 5.0 μm. When the thicknesses of the first hardened layer and the second hardened layer are within this range, a desired gel fraction can be obtained, and as a result, a small change in phase difference can be obtained in a heating environment, in a humidified environment, and after contact with a solvent. , and a retardation film with excellent solvent resistance.

B. Manufacturing method of retardation film B-1. Manufacturing method of resin film As a method for forming the above-mentioned resin film, any appropriate method can be adopted. For example, a melt extrusion method (such as a T-die forming method), a casting coating method (such as a casting method), a calender forming method, a hot pressing method, a co-extrusion method, a co-melting method, a multi-layer extrusion method can be mentioned. Extrusion method, inflation molding method, etc. Preferably, a T-die molding method, a casting method, and an inflation molding method are used.

The thickness of the resin film (ie, the unstretched film) can be set to any appropriate value according to required optical properties, stretching conditions described below, and the like. It is preferably 50 μm to 300 μm, more preferably 80 μm to 250 μm.

B-2. Manufacturing method of stretched resin film Any appropriate stretching direction and stretching conditions (such as stretching temperature, stretching ratio, stretching direction) can be adopted for the above-mentioned stretching, as long as the above-mentioned stretching resin film can be obtained. Specifically, various extension methods such as free-end extension, fixed-end extension-free-end shrinkage, and fixed-end shrinkage can be used individually, or simultaneously or sequentially. Regarding the extending direction, it can be carried out in various directions and/or dimensions such as the horizontal direction, the vertical direction, the thickness direction, and the diagonal direction. The extension temperature is preferably in the range of the glass transition temperature (Tg) of the resin film ±20°C.

By appropriately selecting the above-mentioned stretching method and stretching conditions, a retardation film having desired optical properties (eg, in-plane retardation) can be finally obtained.

In one embodiment, the stretched resin film is produced by uniaxial stretching or fixed end uniaxial stretching of the resin film. As a specific example of uniaxial stretching, the method of extending in the longitudinal direction (that is, longitudinal direction) while moving the resin film in the longitudinal direction can be mentioned. The stretching ratio is preferably 10% to 500%.

In another embodiment, the stretched resin film is produced by continuously extending the elongated resin film obliquely in a direction at an angle θ with respect to the longitudinal direction. By adopting the oblique stretching, an elongated stretched resin film having an alignment angle of angle θ with respect to the longitudinal direction of the film can be obtained. For example, when laminating with a polarizer, roll-to-roll can be achieved, thereby simplifying the manufacturing process.

As a stretching machine for oblique stretching, for example, a tenter-type stretching machine capable of applying a feed force, a stretching force, or a pulling force having different left and right speeds to the transverse direction and/or the longitudinal direction is exemplified. The tenter-type stretching machine includes a transverse uniaxial stretching machine, a simultaneous biaxial stretching machine, and the like, and any appropriate stretching machine can be used as long as the elongated resin film can be continuously stretched obliquely.

As a method of extending obliquely, for example, Japanese Patent Laid-Open No. 50-83482, Japanese Patent Laid-Open No. 2-113920, Japanese Patent Laid-Open No. 3-182701, and Japanese Patent Laid-Open No. 2000-9912 can be mentioned. No. , Japanese Patent Laid-Open No. 2002-86554, and Japanese Patent Laid-Open No. 2002-22944.

The thickness of the stretched resin film is preferably 10 μm to 90 μm, more preferably 20 μm to 50 μm.

As the stretched resin film, a commercially available film may be used as it is, or a commercially available film may be subjected to secondary processing (eg, stretching treatment, surface treatment) according to the purpose and used. As a specific example of a commercially available film, the trade name "PURE-ACE RM" by Teijin Corporation is mentioned.

In one embodiment, relaxation treatment is performed on the stretched resin film. Thereby, the stress which arises by extension can be relieve|moderated. Any appropriate conditions can be adopted as relaxation treatment conditions. For example, the stretched resin film is shrunk at a specific relaxation temperature and a specific relaxation rate (ie, shrinkage rate) in the extending direction. The relaxation temperature is preferably 60°C to 150°C. The relaxation rate is preferably 3% to 6%.

B-3. Post-crosslinking (formation of the first hardened layer and the second hardened layer) In one embodiment, a polyethylene terephthalate (PET) film is roll-laminated on both sides of the above stretched resin film through a reactive composition comprising a crosslinking agent and a free radical generator. A first hardened layer and a second hardened layer can be formed by subjecting the obtained laminate to a crosslinking reaction. In another embodiment, the surface of the stretched resin film is coated with a reactive composition comprising a cross-linking agent and a free-radical generator (a diluting solvent included as needed), and after heat treatment as needed, under a nitrogen atmosphere ( The crosslinking reaction is carried out by heat or UV irradiation), whereby a hardened layer can be obtained. By performing this operation on both sides of the stretched resin film, the first cured layer and the second cured layer can be formed on the surface of the stretched resin film (retardation layer). When forming such a 1st hardened layer and a 2nd hardened layer, the resin which forms a stretched resin film does not need to contain a crosslinkable group. When a resin containing a crosslinkable group is used to manufacture a stretched resin film, problems such as gelation of the resin during manufacturing steps (eg, kneading, extrusion, and stretching) may arise. According to embodiment of this invention, the retardation film which has a 1st hardened layer and a 2nd hardened layer can be manufactured, without generating the said problem. Furthermore, after crosslinking according to the embodiment of the present invention, it can be used for the production of the retardation film of the embodiment of the present invention without changing the normal retardation film and the steps of producing the retardation film. The present invention has an excellent effect in this respect.

As shown in another embodiment described above, when the reactive composition is applied to the surface of the stretched resin film, in order to promote the penetration of the crosslinking agent into the stretched resin film, a heat treatment may be performed. The heating temperature of the heat treatment is preferably a temperature lower than the glass transition temperature of the resin of the stretched resin film. This is because the retardation of the stretched resin film decreases when the heat treatment is performed at a temperature higher than the glass transition temperature. In the case of using a cross-linking agent having high permeability to the stretched resin film, this heat treatment is not required. Also, in the case where a volatile solvent is contained in the reactive composition, the heat treatment may be performed in combination with the drying step.

As said radical generator, a thermal radical generator and a photoradical generator are mentioned typically, and both can be used. Further, the radical generator includes a cleavage-type radical generator and a hydrogen abstraction type radical generator, and it is preferable to use a hydrogen abstraction type radical generator such as a hydrogen abstraction type radical generator which has a higher hydrogen abstraction ability. That is, in the embodiment of the present invention, a hydrogen abstraction type thermal radical generator or a hydrogen abstraction type photoradical generator is suitably used. It is considered that the hydrogen abstraction type radical generator becomes a radical, and the radical deprives the hydrogen in the resin contained in the retardation film to generate a radical in the chemical structure of the resin, and the monomer is polymerized from this as a starting point ( addition) reaction. The reason for this is that in the embodiment of the present invention, since a polyfunctional monomer is used as the above-mentioned crosslinking agent, the reaction point thereof becomes a crosslinking point.

Examples of the above-mentioned hydrogen abstraction type thermal radical generator include organic peroxides, for example: PERBUTYL D, PERBUTYL C, PERCUMYL D, PERHEXYL D, PERBUTYL E, PERBUTYL I, PERHEXYL I, PERBUTYL Z, PERHEXYL Z, PERBUTYL A , PERBUTYL 355, PERBUTYL L, PERBUTYL O, PERHEXYL O, PEROCTA O, PERBUTYL PV, PERHEXYL PV, PERBUTYL ND, PERHEXYL ND, PEROCTA ND, PERHEXA V, PERHEXA 22, PERHEXA 3M, PERHEXA C, PERHEXA HC, PERTETRA A, PERHEXA MC, NYPER BW, PEROYL 355, PEROYL L. As the above-mentioned hydrogen abstraction type photoradical generator, those described in Japanese Patent Laid-Open No. 2012-52000 may, for example, be mentioned. Furthermore, 3,3',4,4'-tetrakis (tert-butylperoxycarbonyl) benzophenone (BTTB), PERDUAL TA, and PERDUAL TX can also be mentioned.

The retardation film obtained above can be subjected to a matrix-assisted laser desorption free time-of-flight mass spectrometer (MALDI-TOFMS, manufactured by BRUKER DALTONICS) after high-temperature methanolysis treatment. Whether or not the above-mentioned post-crosslinking reaction has been performed can be evaluated based on whether or not a repeating pattern derived from the crosslinking reaction is obtained.

C. Circular polarizer The circularly polarizing plate which concerns on embodiment of this invention has the retardation film described in the said item A and B, and a polarizing element. A protective layer can be disposed on at least one side of the polarizing element. The angle formed by the retardation axis of the retardation layer of the retardation film and the absorption axis of the polarizing element is preferably 35° to 55°, more preferably 40° to 50°, particularly preferably 43° to 47°, the best is about 45°.

As the polarizing element, any appropriate polarizing element can be used. For example, the resin film forming the polarizing element may be a single-layer resin film, or may be a laminate of two or more layers.

Specific examples of the polarizer composed of a single-layer resin film include hydrophilicity to polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymer-based partially saponified films. The polymer film has been dyed and stretched with dichroic substances such as iodine or dichroic dyes; polyene-based alignment films such as PVA dehydration products or polyvinyl chloride dehydrochlorination products, etc. From the viewpoint of being excellent in optical properties, it is preferable to use a polarizing element obtained by uniaxially stretching a PVA-based film by dyeing it with iodine.

The above-mentioned dyeing with iodine is performed, for example, by immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the above-mentioned uniaxial stretching is preferably 3 times to 7 times. The stretching can be carried out after the dyeing treatment, or can be carried out while dyeing. In addition, it is also possible to extend and then dye. The PVA-based film is subjected to swelling treatment, crosslinking treatment, washing treatment, drying treatment, and the like as necessary. For example, by immersing the PVA film in water and washing it before dyeing, not only the dirt and/or anti-blocking agent on the surface of the PVA film can be removed, but also the PVA film can be swelled and uneven dyeing can be prevented.

As a specific example of a polarizing element obtained by using a laminate, a polarizing element obtained by using a laminate comprising a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material can be exemplified. ), or a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. A polarizing element obtained by using a laminate of a resin base material and a PVA-based resin layer formed on the resin base material can be produced, for example, by applying a PVA-based resin solution to a resin base material and drying it to obtain a polarizing element. A PVA-based resin layer is formed on a resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; the laminate is extended and dyed to make the PVA-based resin layer into a polarizer. In the present embodiment, the stretching typically includes stretching the layered body by immersing it in a boric acid aqueous solution. Furthermore, the stretching may further include performing in-air stretching of the laminated body at a high temperature (eg, 95° C. or higher) before stretching in a boric acid aqueous solution, if necessary. The obtained laminate of resin substrate/polarizing element can be used as it is (that is, the resin substrate can be used as a protective layer of the polarizing element), or the resin substrate can be peeled off from the laminate of resin substrate/polarizing element, and the This peeling area layer is used with any appropriate protective layer according to the purpose. Details of the manufacturing method of such a polarizing element are described in, for example, Japanese Patent Laid-Open No. 2012-73580. The entire description of this gazette is incorporated herein by reference.

The thickness of the polarizing element is, for example, 1 μm to 80 μm. In one embodiment, the thickness of the polarizing element is preferably 1 μm˜15 μm, more preferably 3 μm˜10 μm, and more preferably 3 μm˜8 μm. When the thickness of the polarizing element is within such a range, curling during heating can be suppressed favorably, and favorable appearance durability during heating can be obtained.

D. Image Display Device The retardation film described in the above-mentioned items A and B and the circularly polarizing plate described in the item C can be used for an image display device. Therefore, an image display device using such an optical laminate is also included in the embodiment of the present invention. Typical examples of the image display device include a liquid crystal display device and an organic EL display device. An image display device according to an embodiment of the present invention includes the retardation film described in the above-mentioned items A and B, and the circular polarizing plate described in the item C. [Example]

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. In addition, "parts" and "%" in Examples and Comparative Examples are based on weight unless otherwise specified.

(1) Thickness The measurement was performed using a dial gauge (manufactured by PEACOCK, product name "DG-205 type pds-2"). (2) Phase difference value A sample of 50 mm×50 mm was cut out from the retardation film obtained in the example and the comparative example as a measurement sample, and the measurement was carried out using Axoscan manufactured by Axometrics. The measurement wavelengths were 450 nm, 550 nm, and 650 nm, and the measurement temperature was 23°C. (3) Heating phase difference change A sample was produced by bonding the retardation film obtained in the Example and the comparative example to glass through the adhesive bond layer, and the retardation was measured by the method similar to the measurement of the said retardation. The sample after the measurement was placed in an oven at 105° C. for 120 hours, then the sample was taken out, the phase difference was measured again, and the rate of change of Re(550) was calculated. (4) Humidification phase difference change A sample was produced by bonding the retardation film obtained in the Example and the comparative example to glass through the adhesive bond layer, and the retardation was measured by the method similar to the measurement of the said retardation. The sample after the measurement was placed in an oven at 85°C and a humidity of 85% for 120 hours, then the sample was taken out, the phase difference was measured again, and the rate of change (%) of Re(550) was determined. (5) Phase difference change after contact with solvent With respect to the retardation films obtained in Examples and Comparative Examples, the retardation was measured by the same method as the measurement of the above-mentioned retardation. Toluene or cyclopentanone was added dropwise to the sample after the measurement, and the solvent was wiped off after 1 minute. After the solvent was wiped off, the phase difference of the portion in contact with the solvent was measured again, and the rate of change (%) of Re(550) was determined. (6) Solvent resistance test Toluene or cyclopentanone was added dropwise to the retardation films obtained in Examples and Comparative Examples, and the solvent was wiped off after 1 minute. After wiping off the solvent, no traces were left on the parts where the solvent was in contact, and those with traces were evaluated as poor. (7) Gel fraction The retardation films obtained in the Examples and Comparative Examples with a square of about 5 cm were collected, and after measuring the weight, they were immersed in 50 g of toluene for 1 hour. After the immersion, the residue was taken out, dried at 150° C. for 10 minutes, the weight was measured again, and the gel fraction (%) was calculated.

[Example 1] 1. Preparation of polycarbonate resin Polymerization was performed using a batch polymerization apparatus including two vertical reactors equipped with stirring blades and a reflux cooler controlled at 100°C. 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)perpen-9-yl]methane, 29.21 parts by mass (0.200 mol) of ISB, 42.28 parts by mass (0.139 mol) of SPG, and 63.77 parts by mass of DPC were added parts by mass (0.298 mol) and 1.19×10 ⁻² mass parts (6.78×10 ⁻⁵ mol) of calcium acetate monohydrate as a catalyst. After the inside of the reactor was replaced with nitrogen under reduced pressure, it was heated with a heat medium, and stirring was started when the internal temperature reached 100°C. 40 minutes after the start of the temperature increase, the internal temperature was brought to 220°C, and the pressure was reduced to 13.3 kPa in 90 minutes after reaching 220°C while controlling to maintain the temperature. The phenol vapor produced by the polymerization reaction was introduced into a reflux cooler at 100°C, and some monomer components contained in the phenol vapor were returned to the reactor, and the uncondensed phenol vapor was introduced into a condenser at 45°C for recovery. After nitrogen gas was introduced into the first reactor and the pressure was temporarily returned to atmospheric pressure, the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Then, the temperature increase and pressure reduction in the second reactor were started, and the internal temperature was set to 240° C. and the pressure to 0.2 kPa over 50 minutes. After that, polymerization is carried out until a certain stirring power is reached. When a specific power is reached, nitrogen gas is introduced into the reactor for re-pressurization, the produced polyester carbonate is extruded into water, and the strands are cut to obtain pellets.

2. Preparation of resin film After vacuum-drying the obtained polycarbonate resin at 80°C for 5 hours, a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder setting temperature: 250°C) and a T-die (width 200 mm, set Temperature: 250°C), a cooling roll (set temperature: 120-130°C), and a film-forming device of a winder to produce a resin film with a thickness of 135 μm.

3. Fabrication of stretched resin film The obtained long resin film was stretched in the width direction at a stretching temperature of 134° C. and a stretching ratio of 2.8 times, and then, relaxation treatment was performed in the width direction of the stretched film. The conditions of the relaxation treatment were set to a relaxation temperature of 130° C. and a relaxation rate of 4.5%. Next, a stretched resin film with a thickness of 48 μm was obtained by performing heat treatment at 125° C. for 2 minutes. Re(550) of the obtained stretched resin film was 180 nm, and Re(450)/Re(550) was 0.85.

4. Post-crosslinking 10 parts by mass of 1,1,3,3-tetramethylbutyl peroxide 2-ethylhexanoate (manufactured by NOF Corporation, product name "PEROCTA O") as a hydrogen abstraction type thermal radical generator A reactive composition 1 was prepared by mixing with 100 parts by mass of tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "A-DCP") as a crosslinking agent. Through the reactive composition 1, a polyethylene terephthalate (PET) film (thickness 50 μm) was roll-laminated on both sides of the stretched resin film obtained in the above 3., to obtain a film with “PET film/reaction”. A laminate of the composition of reactive composition 1/stretched resin film/reactive composition 1/PET film". This layered body was subjected to a heat treatment at 120° C. for 10 minutes to perform a crosslinking treatment. Next, the PET films on both surfaces of the laminate were peeled off to obtain a retardation film. The obtained retardation film had a thickness of 50 μm, a Re(550) of 144 nm, a Re(450)/Re(550) of 0.85, and a haze of 0.7%. The obtained retardation film was used for the evaluation of the above-mentioned (3) to (7). The results are shown in Table 1.

(ISB＋PMA加成物)：推定鍵結位置 [化16]

(單獨PMA) ISB＋PMA加成物之存在意味著於聚酯碳酸酯樹脂中，多官能丙烯酸單體形成有碳-碳鍵。 5. Evaluation of post-crosslinking The retardation film obtained in 4. was subjected to high temperature methanol decomposition treatment, and the methyl ester obtained by decomposition was subjected to MALDI-TOFMS measurement. The results confirmed that in addition to the presence of methyl acrylate (PMA) monomer, There is also an isosorbide (ISB) + PMA adduct. The ISB+PMA adduct was identified by the following method: The Na adduct of an oligomer obtained by adding methyl acrylate to isosorbide was detected as m/z=146.0579(ISB)+86.0348(PMA)× The peak group represented by n+22.99. The PMA monomer system not bound to isosorbide was identified by the following method: The Na adduct of the oligomer of methyl acrylate was detected as represented by m/z=0+86.0348(PMA)×n+22.99 peak group. [Chemical 15]

(ISB+PMA adduct): Presumed bond position [Chemical 16]

(PMA alone) The presence of the ISB+PMA adduct means that in the polyester carbonate resin, the polyfunctional acrylic monomer forms a carbon-carbon bond.

[Example 2] A stretched resin film was obtained in the same manner as in Example 1 except that the stretching temperature and the stretching ratio were appropriately adjusted. The thickness of the stretched resin film was 48 μm, Re(550) was 147 nm, and Re(450)/Re(550) was 0.85.

(日本化藥公司製造，商品名「DETX-S」)1質量份、作為交聯劑之1,6-己二醇二丙烯酸酯(新中村化學工業公司製造，製品名「A-HD-N」)50重量份及三羥甲基丙烷三丙烯酸酯(新中村化學工業公司製造，製品名「A-TMPT」)50質量份加以混合，製備反應性組合物2。經由上述反應性組合物2，將聚對苯二甲酸乙二酯(PET)膜(厚度50 μm)輥式層壓於上述延伸樹脂膜之兩面，獲得具有「PET膜/反應性組合物2/延伸樹脂膜/反應性組合物2/PET膜」之構成之積層體。對該積層體進行UV照射(900 mJ/cm ²)而進行交聯處理。繼而，將該積層體之兩面之PET膜剝離，獲得相位差膜。所獲得之相位差膜之厚度為50 μm，Re(550)為144 nm，Re(450)/Re(550)為0.85，霧度為0.9%。將所獲得之相位差膜供於上述(3)～(7)之評估。將結果示於表1。 2,4-diethyl 9-oxothiocyanate will be used as hydrogen abstraction type photoradical generator

(manufactured by Nippon Kayaku Co., Ltd., trade name "DETX-S") 1 part by mass, 1,6-hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name "A-HD-N") as a crosslinking agent ”) 50 parts by weight and 50 parts by weight of trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name “A-TMPT”) were mixed to prepare reactive composition 2. Through the above-mentioned reactive composition 2, a polyethylene terephthalate (PET) film (thickness 50 μm) was roll-laminated on both sides of the above-mentioned stretched resin film to obtain a film with “PET film/reactive composition 2/ Laminated product of the composition of stretched resin film/reactive composition 2/PET film". This layered product was subjected to UV irradiation (900 mJ/cm ² ) to perform crosslinking treatment. Next, the PET films on both surfaces of the laminate were peeled off to obtain a retardation film. The obtained retardation film had a thickness of 50 μm, a Re(550) of 144 nm, a Re(450)/Re(550) of 0.85, and a haze of 0.9%. The obtained retardation film was used for the evaluation of the above-mentioned (3) to (7). The results are shown in Table 1.

[Example 3] A stretched resin film was obtained in the same manner as in Example 1 except that the stretching temperature and the stretching ratio were appropriately adjusted. The thickness of the stretched resin film was 48 μm, Re(550) was 165 nm, and Re(450)/Re(550) was 0.85.

3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone (manufactured by NOF Corporation, product name "BTTB-20G" (PGMEA) will be used as a hydrogen abstraction type photoradical generator. 20% by weight solution)) 10 parts by weight, 1,6-hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "A-HD-N") as a crosslinking agent 50 parts by weight and trihydroxy 50 parts by mass of methylpropane triacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "A-TMPT") was mixed to prepare reactive composition 3. The above-mentioned reactive composition 3 was bar-coated on one side surface of the above-mentioned stretched resin film, heat-treated at 50° C. for 10 minutes, and then cross-linked by UV irradiation (900 mJ/cm ² ) in a nitrogen atmosphere deal with. Furthermore, in the same manner, the reactive composition was also bar-coated on the other surface, heat-treated at 50° C. for 10 minutes, and then subjected to UV irradiation (900 mJ/cm ² ) in a nitrogen atmosphere for cross-exchange. A retardation film is obtained by joint processing. The obtained retardation film had a thickness of 55 μm, a Re(550) of 144 nm, a Re(450)/Re(550) of 0.85, and a haze of 0.7%. The obtained retardation film was used for the evaluation of the above-mentioned (3) to (7). The results are shown in Table 1.

[Comparative Example 1] A retardation film was obtained in the same manner as in Example 1, except that the stretching temperature and the stretching ratio were appropriately adjusted, and the crosslinking treatment using the reactive composition was not performed as in Examples 1 and 2. The retardation film had a thickness of 48 μm, a Re(550) of 144 nm, a Re(450)/Re(550) of 0.85, and a haze of 0.3%. The obtained retardation film was used for the evaluation of the above-mentioned (3) to (7). The results are shown in Table 1.

[Table 1] Phase difference change rate (%) Phase difference change after exposure to solvent (%) Solvent resistance Gel fraction (%) Heating phase difference change rate Humidification phase difference change rate exposure to toluene contact with cyclopentanone Toluene resistance cyclopentanone resistance Example 1 +2.1 -1.1 -0.1 0.0 good good 98.5 Example 2 +2.5 -2.5 0.0 -0.3 good good 98.7 Example 3 +1.8 -2.3 0.0 -0.3 good good 98.9 Comparative Example 1 +3.0 -4.0 -18.9 -78.2 bad bad 0

As can be seen from Table 1, the retardation films according to the examples of the present invention have small changes in retardation after the heating test, after the humidification test, and after contact with the solvent, and are also excellent in solvent resistance. [Industrial Availability]

The retardation film of the embodiment of the present invention is suitable for use in a circularly polarizing plate and an image display device.

10: The first hardened layer 20: retardation layer 30: Second hardened layer 100: retardation film

FIG. 1 is a schematic cross-sectional view of a retardation film according to an embodiment of the present invention.

10: The first hardened layer

20: retardation layer

30: Second hardened layer

100: retardation film

Claims (12)

A retardation film comprising a first hardened layer, a retardation layer and a second hardened layer in this order, The retardation layer is formed of a stretched resin film, The stretched resin film comprises a resin having at least one bonding group selected from carbonate bonds and ester bonds, In the first hardened layer and the second hardened layer, the crosslinking agent having a carbon-carbon double bond and the resin are crosslinked via the carbon-carbon double bond. The retardation film according to claim 1, wherein the above-mentioned resin comprises a structural unit represented by the following formula; [Chemical 1]

. The retardation film according to claim 1 or 2, wherein the above-mentioned resin comprises a structural unit represented by the following formula; [Chemical 2]

. The retardation film according to any one of claims 1 to 3, which satisfies the relationship of Re(450)<Re(550)<Re(650). The retardation film according to any one of claims 1 to 4, which satisfies the relationship of 0.7<Re(450)/Re(550)<1.0. The retardation film according to any one of claims 1 to 5, wherein Re(550) is 100 nm to 180 nm or 220 nm to 330 nm. A circularly polarizing plate comprising the retardation film and a polarizing element according to any one of claims 1 to 6. An image display device including the retardation film according to any one of claims 1 to 6. An image display device including the circular polarizing plate as claimed in claim 7. A method for producing a retardation film, which is the method for producing a retardation film according to any one of claims 1 to 6, comprising using a radical generator to pass the above-mentioned resin and the above-mentioned cross-linking agent through the above-mentioned carbon of the above-mentioned cross-linking agent - the step of cross-linking the carbon double bonds. The method for producing a retardation film according to claim 10, wherein the radical generator is a hydrogen abstraction type photoradical generator. The method for producing a retardation film according to claim 10, wherein the radical generator is a hydrogen abstraction type thermal radical generator.

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