JPWO2018003416A1 - Retardation film - Google Patents

Abstract

[Problem] To provide a retardation film which is excellent in light leakage suppression at the time of black display. [Solution] A retardation film having at least two retardation layers and having a first retardation layer and a second retardation layer, wherein the first retardation layer has the formula (1) and The second retardation layer has optical properties represented by the formulas (3) and (4), and the second retardation layer has optical properties represented by the formulas (2), (3) and (4). Retardation film wherein the retardation film has optical properties represented by Formula (2), Formula (3) and Formula (4). 200 nm <Re (550) <320 nm (1) 100 nm <Re (550) <160 nm (2) Re (450) / Re (550) ≦ 1.00 (3) 1.00 ≦ Re (650) / Re (550) (4) (wherein, Re (450) represents an in-plane retardation value at a wavelength of 450 nm, Re (550) represents an in-plane retardation value at a wavelength of 550 nm, and Re (650) represents an in-plane retardation at a wavelength of 650 nm. Represents a phase difference value) [Selected drawing] FIG.

Description

  The present invention relates to a retardation film.

  In a flat panel display (FPD), a member including an optical film such as a polarizing plate or a retardation plate is used. As such an optical film, an optical film produced by applying a composition containing a polymerizable liquid crystal to a substrate is known. For example, Patent Document 1 describes the optical film exhibiting reverse wavelength dispersion.

Japanese Patent Publication No. 2010-537955

  However, when used under strong light such as sunlight, the color of the reflected light is made a neutral hue, because even if the reflected light is slightly colored, it affects the color of the image. Was required.

The present invention includes the following inventions.
[1] A retardation film having at least two retardation layers, and having a first retardation layer and a second retardation layer,
The first retardation layer is
It has an optical characteristic represented by Formula (1), Formula (3) and Formula (4),
The second retardation layer is
(2) and (3) and (4) have the optical properties,
The retardation film is
The retardation film which has an optical characteristic represented by Formula (2) and Formula (3) and Formula (4).
200 nm <Re (550) <320 nm (1)
100 nm <Re (550) <160 nm (2)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
(Wherein, Re (450) represents an in-plane retardation value at a wavelength of 450 nm, Re (550) represents an in-plane retardation value at a wavelength of 550 nm, and Re (650) represents an in-plane retardation value at a wavelength of 650 nm. Represent)
[2] The retardation film according to [1], further having a third retardation layer represented by Formula (5).
nx ny ny <nz (5)
(Nx represents the main refractive index in the direction parallel to the film plane in the refractive index ellipsoid formed by the retardation layer, ny represents the refractive index ellipsoid formed by the retardation layer relative to the film plane Represents the refractive index in the direction perpendicular to the direction of nx, and nz represents the refractive index in the direction perpendicular to the film plane in the refractive index ellipsoid formed by the retardation layer. Represent)
It is a retardation film as described in [3] [1] or [2], Comprising: The retardation film which has an optical characteristic represented by Formula (6) and (7).
−2.0 ≦ a * ≦ 0.5 (6)
−0.5 ≦ b * ≦ 5.0 (7)
(Wherein, a * and b * represent color coordinates in the L * a * b * color system)
[4] The retardation film according to any one of [1] to [3], wherein the first retardation layer is a coating layer formed by polymerizing one or more polymerizable liquid crystals.
[5] The retardation film according to any one of [1] to [4], wherein the second retardation layer is a coating layer formed by polymerizing one or more polymerizable liquid crystals.
[6] The retardation film according to any one of [1] to [5], wherein the thickness of the first retardation layer is 5 μm or less.
[7] The retardation film according to any one of [1] to [6], wherein the thickness of the second retardation layer is 5 μm or less.
[8] The retardation film according to any one of [1] to [7], wherein the thickness of the first retardation layer and the thickness of the second retardation layer are each 5 μm or less.
[9] A first retardation layer is formed on the substrate with or without the alignment film, and a second retardation layer is formed on the first retardation layer with or without the alignment film. The retardation film as described in any one of [1]-[8] in which the retardation layer is formed.
[10] A second retardation layer is formed on the substrate with or without the alignment film, and a first retardation layer is formed on the second retardation layer with or without the alignment film. The phase difference film as described in any one of [1]-[9] in which the phase difference layer is formed.
[11] A first retardation layer is formed on one surface of the substrate with or without the alignment film, and the other surface of the substrate with or without the alignment film is formed. The phase difference film as described in any one of [1]-[9] in which the phase difference layer is formed.
[12] The substrate has the optical properties of the first retardation layer, and the second retardation layer is formed on the substrate with or without the alignment film [1] to [9] ] The retardation film as described in any one of-.
[13] The substrate has the optical properties of the second retardation layer, and the first retardation layer is formed on the substrate with or without the alignment film [1] to [9] ] The retardation film as described in any one of-.
[14] The retardation film according to any one of [1] to [9], wherein the angle between the optical axes of the first retardation layer and the second retardation layer is substantially 60 °.
[15] The retardation film according to any one of [7] to [12], which has a protective layer between the first retardation layer and the second retardation layer.
[16] A circularly polarizing plate comprising the retardation film according to any one of [1] to [15] and a polarizing plate.
[17] The angle between the absorption axis or transmission axis of the polarizing plate and the optical axis of the second retardation layer with respect to the angle θ between the absorption axis or transmission axis of the polarizing plate and the optical axis of the first retardation layer The circularly polarizing plate according to [16], wherein is substantially a relationship of 2θ + 45 °.
The organic electroluminescence display provided with the circularly-polarizing plate as described in [18] [16] or [17].
[19] A touch panel display device comprising the circularly polarizing plate according to [16] or [17].

  According to the present invention, it is possible to provide an optical film which is excellent in light leakage suppression at the time of black display.

It is a cross-sectional schematic diagram of the retardation film of this invention. It is a cross-sectional schematic diagram of the circularly-polarizing plate of this invention. It is a cross-sectional schematic diagram of the organic electroluminescence display containing the circularly-polarizing plate of this invention.

The retardation film of the present invention (hereinafter sometimes referred to as the present retardation film) has a first retardation layer and a second retardation layer. Moreover, you may have a 3rd phase difference layer. The first retardation layer, the second retardation layer and the third retardation layer are retardation layers having constant optical properties, and the first retardation layer, the second retardation layer and the third retardation layer The phase difference layers of each may consist of two or more layers.
The present retardation film is an optical film having at least two retardation layers, and preferably has optical properties represented by formulas (6) and (7). By having such optical properties, it is possible to obtain a retardation film excellent in transparency in the visible light region, and to suppress light leakage and coloration at the time of black display.
−2.0 ≦ a * ≦ 0.5 (6)
−0.5 ≦ b * ≦ 5.0 (7)
(Wherein, a * and b * represent color coordinates in the L * a * b * color system)
The chromaticity a * and b * in the range represented by Formula (6) and Formula (7) are greatly influenced by the optical properties of the retardation layer in the present retardation film. As described later, in the case of a layer formed by polymerizing a polymerizable liquid crystal, the retardation layer has a large value of a * and b * when the retardation layer is colored. When the retardation layer is formed of a stretched film, the values of a * and b * increase when the absorption wavelength of the resin forming the stretched film reaches the visible range. That is, in order to control a * in the range represented by Formula (6) and b * in the range represented by Formula (7), as long as the polymerizable liquid crystal or the resin side chain can be in the visible range A material that does not absorb light may be used, and adjustment may be made to maintain transparency even during film formation.

  a * is preferably -1.5 or more and 0.5 or less, more preferably -1.0 or more and 0.5 or less. b * is preferably -0.5 or more and 4.0 or less, and more preferably -0.5 or more and 3.0 or less.

The present retardation film has optical properties represented by the formula (3) and the formula (4), and the first retardation layer and the second retardation layer also have the formulas (3) and (4). It has the optical characteristics shown. In order for the present retardation film to have such optical properties, the first retardation layer and the second retardation layer have the optical properties represented by the formulas (3) and (4), and The phase difference layer may exhibit the optical properties represented by Formula (1) and the second phase difference layer may be represented by Formula (2).
200 nm <Re (550) <320 nm (1)
100 nm <Re (550) <160 nm (2)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
The Re (450) / Re (550) [formula (3)] of the retardation film is preferably 0.90 or less, more preferably 0.85 or less, and usually 0.60 or more, preferably 0. .70 or more.
The Re (650) / Re (550) [formula (4)] of the present retardation film is preferably 1.02 or more, more preferably 1.04 or more, and usually 1.40 or less, preferably Is less than 1.30.
In this specification, Re (450) represents an in-plane retardation value at a wavelength of 450 nm, Re (550) represents an in-plane retardation value at a wavelength of 550 nm, and Re (650) represents an in-plane retardation at a wavelength of 650 nm. Represents a differential value.

[Phase difference layer]
Examples of the retardation layer include a layer formed by polymerizing a polymerizable liquid crystal and a stretched film. The optical properties of the retardation layer can be adjusted by the alignment state of the polymerizable liquid crystal or the stretching method of the stretched film.

<Layer Formed by Polymerization of Polymerizable Liquid Crystal>
In the present invention, the direction in which the optical axis of the polymerizable liquid crystal is aligned horizontally to the substrate plane is defined as horizontal alignment, and the case in which the optical axis of the polymerizable liquid crystal is aligned vertically to the substrate plane is defined as vertical alignment Do. The optical axis means, in a refractive index ellipsoid formed by alignment of a polymerizable liquid crystal, a direction in which a section cut out in a direction perpendicular to the optical axis is a circle, that is, a direction in which all three refractive indices are equal. .

Examples of the polymerizable liquid crystal include rod-like polymerizable liquid crystals and disc-like polymerizable liquid crystals.
When the rod-like polymerizable liquid crystal is horizontally or vertically aligned with the substrate, the optical axis of the polymerizable liquid crystal coincides with the long axis direction of the polymerizable liquid crystal.
When the discotic polymerizable liquid crystal is aligned, the optical axis of the polymerizable liquid crystal is in the direction orthogonal to the disc surface of the polymerizable liquid crystal.

  The slow axis direction of the stretched film differs depending on the stretching method, and the slow axis and the optical axis are determined depending on the stretching method such as uniaxial, biaxial or oblique stretching.

  In order for the layer formed by polymerizing the polymerizable liquid crystal to exhibit an in-plane retardation, the polymerizable liquid crystal may be oriented in a suitable direction. When the polymerizable liquid crystal is rod-like, the in-plane retardation is expressed by orienting the optical axis of the polymerizable liquid crystal horizontally to the substrate plane. In this case, the optical axis direction and the slow axis direction are Match When the polymerizable liquid crystal is disc-shaped, the in-plane retardation is expressed by orienting the optical axis of the polymerizable liquid crystal horizontally to the substrate plane. In this case, the optical axis and the slow axis are orthogonal to each other. Do. The alignment state of the polymerizable liquid crystal can be adjusted by the combination of the alignment film and the polymerizable liquid crystal.

The in-plane retardation value of the retardation layer can be adjusted by the thickness of the retardation layer. Since the in-plane retardation value is determined by Expression (10), in order to obtain a desired in-plane retardation value (Re (λ)), Δn (λ) and the film thickness d may be adjusted.
Re (λ) = d × Δn (λ) (10)
In the formula, Re (λ) represents an in-plane retardation value at a wavelength λ nm, d represents a film thickness, and Δn (λ) represents a birefringence index at a wavelength λ nm.

  The birefringence Δn (λ) is obtained by measuring the in-plane retardation value and dividing by the thickness of the retardation layer. Although a specific measurement method is shown in the examples, in this case, by measuring a film formed on a substrate having no in-plane retardation on the substrate itself like a glass substrate, a substantial position can be obtained. The characteristics of the phase difference layer can be measured.

  In the present invention, the refractive indexes in three directions in the refractive index ellipsoid formed by the orientation of the polymerizable liquid crystal or the stretching of the film are represented as nx, ny and nz. nx represents the main refractive index in the direction parallel to the film plane in the refractive index ellipsoid formed by the retardation layer. In the refractive index ellipsoid formed by the retardation layer, ny represents the refractive index in the direction parallel to the film plane and orthogonal to the nx direction. nz represents the refractive index in the direction perpendicular to the film plane in the refractive index ellipsoid formed by the retardation layer.

  When the optical axis of the rod-like polymerizable liquid crystal is aligned horizontally to the substrate plane, the refractive index relationship of the obtained retardation layer is nx> ny ≒ nz (positive A plate), and the refractive index ellipsoid is The axis in the direction of nx coincides with the slow axis.

  When the optical axis of the discotic polymerizable liquid crystal is aligned horizontally to the substrate plane, the refractive index relationship of the obtained retardation layer is nx <ny ≒ nz (negative A plate), and the refractive index The axis in the direction of ny in the ellipsoid coincides with the slow axis.

In order for the layer formed by polymerizing the polymerizable liquid crystal to exhibit retardation in the thickness direction, the polymerizable liquid crystal may be oriented in a suitable direction. In the present invention, to express the phase difference in the thickness direction is defined as showing a characteristic that Rth (retardation value in the thickness direction) becomes negative in Expression (20). Rth can be calculated from a phase difference value (R ₄₀ ) measured at an inclination of 40 degrees with the in-plane fast axis as the inclination axis and the in-plane retardation value (Re). That is, Rth obtains nx, ny and nz from Re, R ₄₀ , d (the thickness of the retardation layer), and n 0 (the average refractive index of the retardation layer) according to the following equations (21) to (23) , These can be calculated by substituting them into equation (20).
Rth = [(nx + ny) / 2-nz] × d (20)
Re = (nx-ny) x d (21)
R ₄₀ = (nx−ny ′) × d / cos (φ) (22)
(nx + ny + nz) / 3 = n0 (23)
here,
φ = sin ⁻¹ [sin (40 °) / n0]
ny '= ny × nz / [ny ² × sin ² (φ) + nz ² × cos ² (φ)] ^1/2
Also, nx, ny and nz are as defined above.

  When the polymerizable liquid crystal is in the form of a rod, the optical axis of the polymerizable liquid crystal is oriented perpendicularly to the plane of the substrate to express a phase difference in the thickness direction. When the polymerizable liquid crystal is disc-shaped, the optical axis of the polymerizable liquid crystal is oriented horizontally to the plane of the substrate to express a phase difference in the thickness direction. In the case of the discotic polymerizable liquid crystal, since the optical axis of the polymerizable liquid crystal is parallel to the substrate plane, the thickness is fixed when Re is determined, so Rth is uniquely determined. In the case of a rod-like polymerizable liquid crystal, since the optical axis of the polymerizable liquid crystal is perpendicular to the plane of the substrate, Rth can be adjusted without changing Re by adjusting the thickness of the retardation layer. Can.

  When the optical axis of the rod-like polymerizable liquid crystal is aligned perpendicular to the substrate plane, the refractive index relationship of the obtained retardation layer is nx ny ny <nz (positive C plate), and the refractive index ellipsoid is The axis in the nz direction coincides with the slow axis direction.

  When the optical axis of the discotic polymerizable liquid crystal is oriented parallel to the substrate plane, the refractive index relationship of the retardation layer obtained is nx <ny ≒ nz (negative A plate), and the refractive index The axis in the direction of ny in the ellipsoid coincides with the direction of the slow axis.

<Polymerizable liquid crystal>
The polymerizable liquid crystal is a compound having a polymerizable group and having liquid crystallinity (hereinafter, referred to as a polymerizable liquid crystal compound). The polymerizable group means a group involved in the polymerization reaction, and is preferably a photopolymerizable functional group. The photopolymerizable functional group means a group capable of participating in the polymerization reaction by active radicals or acids generated from the photopolymerization initiator. Examples of the photopolymerizable functional group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, oxetanyl group and the like. Among them, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable. The liquid crystallinity may be a thermotropic liquid crystal or a lyotropic liquid crystal, but a thermotropic liquid crystal is preferable in that precise film thickness control is possible. The phase order structure in the thermotropic liquid crystal may be nematic liquid crystal or smectic liquid crystal.

  In the present invention, as the polymerizable liquid crystal compound, the structure of the following formula (I) is particularly preferable in that the above-mentioned reverse wavelength dispersion is exhibited.

In formula (I), Ar represents a divalent aromatic group which may have a substituent. The term "aromatic group" as used herein refers to a group having a planar ring structure, and the ring structure has [4n + 2] [pi] electrons in accordance with the Huckels rule. Here, n represents an integer. When the ring structure is formed by containing a hetero atom such as -N = or -S-, the case where the non-covalent electron pair on these hetero atoms is included to satisfy the Hückel rule and has aromaticity is also included. The divalent aromatic group preferably contains at least one or more of a nitrogen atom, an oxygen atom and a sulfur atom.
G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, carbon The carbon atom which may be substituted by the alkoxy group of the number 1-4, a cyano group, or a nitro group and which comprises this bivalent aromatic group or a bivalent alicyclic hydrocarbon group is an oxygen atom, a sulfur atom Or may be substituted by a nitrogen atom.
L ¹ , L ² _, B ¹ and B ² are each independently a single bond or a divalent linking group.
k and l each independently represent an integer of 0 to 3 and satisfy the relationship 1 ≦ k + 1. Here, when 2 ≦ k + 1, B ¹ and B ² , G ¹ and G ² may be identical to or different from each other.
E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, wherein a hydrogen atom contained in the alkanediyl group may be substituted by a halogen atom, and the alkanediyl group may be substituted is, -O - - _-CH 2 contained, - S -, - may be substituted with Si-.
Each of P ¹ and P ² independently represents a polymerizable group or a hydrogen atom, and at least one is a polymerizable group.

G ¹ and G ² are each independently preferably a 1,4-phenylenediyl group which may be substituted by at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms And a 1,4-cyclohexanediyl group which may be substituted by at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, and more preferably 1 substituted by a methyl group , 4-phenylenediyl group, unsubstituted 1,4-phenylenediyl group, or unsubstituted 1,4-trans-cyclohexanediyl group, particularly preferably unsubstituted 1,4-phenylenediyl group, or unsubstituted It is a substituted 1,4-trans-cyclohexanediyl group.
In addition, it is preferable that at least one of the plurality of G ¹ and G ² is a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ^2. More preferably, one is a divalent alicyclic hydrocarbon group.

L ¹ and L ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a1 OR ^a2- , -R ^a3 COOR ^a4- , -R ^{a5 OCOR a6 -, R a7 OC =} OOR a8 -, - N = N -, - CR c = CR d -, or -C≡C-. Here, R ^{a1 to} R ^a8 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and R ^c and R ^d each represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L ¹ and ^{L 2} are each independently more preferably a single _{^{bond, -OR a2-1 -, - CH 2}} -, - CH 2 CH 2 -, - COOR a4-1 -, or ^{-OCOR a6-1} - in is there. Here, R ^a2-1 , R ^a4-1 and R ^a6-1 each independently represent a single bond, -CH _2- or -CH ₂ CH _2- . L ¹ and L ² are each independently more preferably a single bond, —O—, —CH ₂ CH ₂ —, —COO—, —COOCH ₂ CH ₂ —, or —OCO—.

Each of B ¹ and B ² is preferably independently a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10- , -R ^a11 COOR ^a12- , -R ^a13 OCOR ^a14 -, or ^R a15 OC ^{= OOR a16} - a. Here, R ^{a9 to} R ^a16 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B ¹ and B ² are each independently, more preferably a single bond, -OR ^{a10 -1-} , -CH _2- , -CH ₂ CH _2- , ^{-COOR a12 -1-} , or -OCOR ^a14-1- is there. Here, R ^a10-1 , R ^a12-1 and R ^a14-1 each independently represent a single bond, -CH _2- or -CH ₂ CH _2- . B ¹ and ^{B 2} are each independently more preferably a single _{bond, -O -, - CH 2 CH} 2 -, - COO -, - COOCH 2 CH 2 -, - OCO-, or -OCOCH ₂ CH ₂ -, It is.

  k and l are preferably in the range of 2 ≦ k + 1 ≦ 6 from the viewpoint of reverse wavelength dispersive expression, preferably k + 1 = 4, and more preferably k = 2 and l = 2. It is preferable that k = 2 and l = 2 because of a symmetrical structure.

Each of E ¹ and E ² is preferably independently an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms.

As a polymerizable group represented by P ¹ or P ² , an epoxy group, a vinyl group, a vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group And oxetanyl groups and the like.
Among them, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable.

  Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron-withdrawing group. As the said aromatic hydrocarbon ring, a phenyl group, a naphthyl group, an anthracenyl group etc. are mentioned, for example, A phenyl group and a naphthyl group are preferable. As the aromatic heterocyclic ring, furan ring, benzofuran ring, pyrrole ring, indole ring, thiophene ring, benzothiophene ring, pyridine ring, pyrazine ring, pyrimidine ring, triazole ring, triazine ring, pyrroline ring, imidazole ring, pyrazole ring And thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, phenanthroline ring and the like. Among them, it is preferable to have a thiazole ring, a benzothiazole ring or a benzofuran ring, and it is more preferable to have a benzothiazole group. When Ar contains a nitrogen atom, the nitrogen atom preferably has a π electron.

The total number N of _π electrons contained in the divalent aromatic group represented by Ar in the formula (I) is preferably 8 or more, more preferably 10 or more, still more preferably 14 or more, and particularly preferably Preferably it is 16 or more. Moreover, it is preferably 30 or less, more preferably 26 or less, and still more preferably 24 or less.

  Examples of the aromatic group represented by Ar include the following groups.

In formulas (Ar-1) to (Ar-22), the symbol * represents a linking moiety, and Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, or an alkyl having 1 to 12 carbon atoms. Group, cyano group, nitro group, alkylsulfinyl group having 1 to 12 carbon atoms, alkylsulfonyl group having 1 to 12 carbon atoms, carboxyl group, fluoroalkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 6 carbon atoms, C1-C12 alkylthio group, C1-C12 N-alkylamino group, C2-C12 N, N-dialkylamino group, C1-C12 N-alkylsulfamoyl group or carbon 2 to 12 N, N-dialkylsulfamoyl groups are represented.

Each of Q ¹ , Q ² and Q ³ independently represents -CR ^{2 '} R ^3'- , -S-, -NH-, -NR ^{2 '} -, -CO- or -O-, and R ^2' And R ^{3 ′} each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

J ¹ and J ² each independently represent a carbon atom or a nitrogen atom.

Y ¹ , Y ² and Y ³ each independently represent an aromatic hydrocarbon group or aromatic heterocyclic group which may be substituted.

W ¹ and W ² each independently represent a hydrogen atom, a cyano group, a methyl group or a halogen atom, and m represents an integer of 0 to 6.

Examples of the aromatic hydrocarbon group in Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group and biphenyl group, and a phenyl group And a naphthyl group is preferable, and a phenyl group is more preferable. The aromatic heterocyclic group has 4 to 20 carbon atoms which contains at least one hetero atom such as nitrogen atom such as furyl group, pyrrolyl group, thienyl group, pyridinyl group, thiazolyl group, benzothiazolyl group, oxygen atom and sulfur atom An aromatic heterocyclic group is mentioned, and a furyl group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group are preferable.

Y ¹ , Y ² and Y ³ may be each independently a polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group which may be substituted. The polycyclic aromatic hydrocarbon group refers to a condensed polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group means a group derived from a fused polycyclic aromatic heterocyclic group or an aromatic ring assembly.

Z ⁰ , Z ¹ and Z ² are preferably each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms; ⁰ is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z ¹ and Z ² are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a cyano group.

Q ^{1, Q 2} and ^{Q 3} are, -NH -, - S -, - NR 2 '-, - O- are preferable, R ^2' is preferably a hydrogen atom. Among them, -S-, -O- and -NH- are particularly preferable.

Among formulas (Ar-1) to (Ar-22), formulas (Ar-6) and (Ar-7) are preferable from the viewpoint of molecular stability.
In formulas (Ar-16) to (Ar-22), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is attached and Z ⁰ . Examples of the aromatic heterocyclic group include those described above as the aromatic heterocyclic ring which Ar may have, and examples thereof include pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrazine ring, pyrimidine ring, indole And rings, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring and the like. The aromatic heterocyclic group may have a substituent. Y ¹ may be, together with the nitrogen atom to which it is attached and Z ⁰ , an optionally substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group as described above. For example, benzofuran ring, benzothiazole ring, benzoxazole ring and the like can be mentioned.

  The total content of the polymerizable liquid crystal compound in 100 parts by mass of the solid content of the composition for forming an optical anisotropic layer is usually 70 parts by mass to 99.5 parts by mass, preferably 80 parts by mass to 99 It is a mass part, More preferably, it is 80 mass parts-94 mass parts, More preferably, it is 80 mass parts-90 mass parts. If the total content is within the above range, the orientation of the resulting optically anisotropic layer tends to be high. Here, the solid content refers to the total amount of the components excluding the solvent from the composition.

The retardation layer having optical properties represented by the formulas (3) and (4) is obtained when a polymer film having a specific structure is stretched when polymerizing a polymerizable liquid crystal having a specific structure. By combining the first retardation layer with the equation (1) and the second retardation layer with the relationship of the equation (2), retardation films represented by the equations (3) and (4) can be obtained. .
100 nm <Re (550) <160 nm (1)
200 nm <Re (550) <320 nm (2)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)

  Even when the first retardation layer and the second retardation layer do not satisfy the equations (3) and (4), and have the optical properties represented by the equations (1) and (2), Although the present retardation film having optical properties represented by the formulas (3) and (4) can be obtained, both the first retardation layer and the second retardation layer have the formulas (3) and (4). When the optical characteristic represented by) is obtained, even more uniform polarization conversion characteristics can be obtained for light of each wavelength in the visible light range, and light leakage at the time of black display of a display such as an organic EL display Can be greatly suppressed.

Examples of the polymerizable liquid crystal having the specific structure include the polymerizable liquid crystal (I). By orienting the polymerizable liquid crystal (I) so that the optical axis is horizontal to the plane of the substrate, a retardation layer having optical properties represented by the formulas (1) and (2) can be obtained. Further, by adjusting the film thickness in accordance with the equation (10), for example, a retardation layer having a desired in-plane retardation value such as optical properties represented by the equations (1) and (2) is obtained. be able to.
100 nm <Re (550) <160 nm (1)
200 nm <Re (550) <320 nm (2)

<Stretch film>
A stretched film is usually obtained by stretching a substrate. As a method of stretching the substrate, for example, a roll (rolling body) in which the substrate is wound into a roll is prepared, and the substrate is continuously unwound and unwound from the wound body. The substrate is transported to the furnace. The setting temperature of the heating furnace is in the range of around the glass transition temperature of the substrate (° C) to [glass transition temperature + 100] (° C), preferably around the glass transition temperature (° C) to [glass transition temperature + 50] (° C) Range of In the heating furnace, when stretching in the direction of movement of the base material or in the direction perpendicular to the direction of movement, the transport direction and tension are adjusted, and an arbitrary angle is inclined to perform uniaxial or biaxial thermal stretching processing. Do. The magnification of stretching is usually 1.1 to 6 times, preferably 1.1 to 3.5 times.
Moreover, as a method of extending | stretching diagonally, if an orientation axis | shaft can be continuously made to incline to a desired angle, it will not be specifically limited, A well-known extending | stretching method is employable. As such a stretching method, for example, the methods described in JP-A-50-83482 and JP-A-2-113920 can be mentioned. When the film is provided with retardation by stretching, the thickness after stretching is determined by the thickness before stretching and the stretching ratio.

  As a stretched film which has a thickness direction retardation, the stretched film which has a refractive index relationship of nx <ny <nz of Unexamined-Japanese-Patent No. 2008-129465, for example, and a well-known multilayer extrusion film can be mentioned. Even in a film having a refractive index relationship of nx <ny <nz, since nz is relatively large, an effect equivalent to nx 同等 ny <nz can be obtained.

  The in-plane retardation value and the retardation value in the thickness direction of the stretched film can be adjusted by Δn (λ) and the film thickness d, as in the layer formed by polymerizing the polymerizable liquid crystal.

  Examples of the stretched film obtained by stretching a polymer film having a specific structure and having the optical properties represented by the formulas (3) and (4) include, for example, commercially available stretched films made of polycarbonate resins. Specifically, “Pure Ace (registered trademark) WR” (manufactured by Teijin Limited) and the like can be mentioned.

  The substrate is usually a transparent substrate. The term "transparent substrate" means a substrate having transparency capable of transmitting light, particularly visible light, and transparency means that the transmittance for light having a wavelength of 380 to 780 nm is 80% or more. Say. In addition, the base material is colorless without coloring, so that a * is controlled within the range represented by formula (6) and b * within the range represented by formula (7). It is easy and preferable.

  As a specific transparent base material, a translucent resin base material is mentioned. As a resin which comprises a translucent resin base material, Polyolefins, such as polyethylene and a polypropylene; Cyclic olefin type resins, such as a norbornene-type polymer; Polyvinyl alcohol; Polyethylene terephthalate; Poly methacrylate; Poly acrylate; Triacetyl cellulose, Cellulose esters such as diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyethersulfone; polyether ketone; polyphenylene sulfide and polyphenylene oxide. From the viewpoint of availability and transparency, polyethylene terephthalate, polymethacrylic acid ester, cellulose ester, cyclic olefin resin or polycarbonate is preferable.

  Cellulose ester is obtained by esterifying some or all of the hydroxyl groups contained in cellulose and can be easily obtained from the market. Also, cellulose ester base materials can be easily obtained from the market. Commercially available cellulose ester substrates include, for example, “Fujitak (registered trademark) film” (Fuji Photo Film Co., Ltd.); “KC8UX2M”, “KC8UY” and “KC4UY” (Konica Minolta Opto Co., Ltd.), etc. Be

The polymethacrylic acid ester and the polyacrylic acid ester (hereinafter, the polymethacrylic acid ester and the polyacrylic acid ester may be collectively referred to as a (meth) acrylic resin.
) Are readily available from the market.

  Examples of (meth) acrylic resins include homopolymers of methacrylic acid alkyl esters or acrylic acid alkyl esters, and copolymers of methacrylic acid alkyl esters and acrylic acid alkyl esters. Specific examples of the methacrylic acid alkyl ester include methyl methacrylate, ethyl methacrylate and propyl methacrylate, and specific examples of the acrylic acid alkyl ester include methyl acrylate, ethyl acrylate and propyl acrylate. As such (meth) acrylic resins, those commercially available as general-purpose (meth) acrylic resins can be used. As the (meth) acrylic resin, one called an impact resistant (meth) acrylic resin may be used.

  It is also preferable to include rubber particles in the (meth) acrylic resin for further mechanical strength improvement. The rubber particles are preferably acrylic. Here, the acrylic rubber particles have a rubber elasticity obtained by polymerizing an acrylic monomer having an acrylic acid alkyl ester such as butyl acrylate or 2-ethylhexyl acrylate as a main component in the presence of a polyfunctional monomer. It is a particle. The acrylic rubber particles may be formed of a single layer of particles having such rubber elasticity, or may be a multilayer structure having at least one rubber elastic layer. As the acrylic rubber particles having a multilayer structure, those having the above-described particles having rubber elasticity as a core and the periphery thereof covered with a hard methacrylic acid alkyl ester type polymer, a hard methacrylic acid alkyl ester type polymer A core is covered with an acrylic polymer having rubber elasticity as described above, and a hard core is covered with a rubber elastic acrylic polymer, and a hard methacrylic acid alkyl ester is further wrapped around the core. What was covered by a system polymer etc. are mentioned. The rubber particles formed of the elastic layer usually have an average diameter in the range of about 50 to 400 nm.

  The content of the rubber particles in the (meth) acrylic resin is usually about 5 to 50 parts by mass per 100 parts by mass of the (meth) acrylic resin. The (meth) acrylic resin and the acrylic rubber particles are commercially available in the state of mixing them, so that commercially available products can be used. As an example of a commercial item of (meth) acrylic resin in which acrylic rubber particles are blended, "HT55X" and "Technoloi S001" sold by Sumitomo Chemical Co., Ltd. can be mentioned. Technoroy S001 is sold in the form of a film.

  Cyclic olefin resins are readily available from the market. As commercially available cyclic olefin resins, "Topas" (registered trademark) (Ticona (Germany)), "Arton" (registered trademark) (JSR Corporation), "ZEONOR" (registered trademark) (Japan) Zeon Co., Ltd., "ZEONEX" (registered trademark) [Nippon Zeon Co., Ltd.], and "APEL" (registered trademark) [Mitsui Chemical Co., Ltd.] can be mentioned. Such a cyclic olefin resin can be formed into a film by a known means such as, for example, a solvent casting method, a melt extrusion method, and the like to be used as a substrate. Moreover, the cyclic olefin resin base material marketed can also be used. As a commercially available cyclic olefin resin base material, "essina" (registered trademark) [Sekisui Chemical Co., Ltd.], "SCA 40" (registered trademark) [Sekisui Chemical Co., Ltd.], "Zeonor Film" (registered trademark) And the like) and “Arton Film” (registered trademark) [JSR Corporation].

  When the cyclic olefin resin is a copolymer of cyclic olefin and an aromatic compound having a chain olefin or a vinyl group, the content ratio of structural units derived from cyclic olefin is the total structural unit of the copolymer. On the other hand, it is usually at most 50 mol%, preferably in the range of 15 to 50 mol%. The linear olefins include ethylene and propylene, and the aromatic compounds having a vinyl group include styrene, α-methylstyrene and alkyl-substituted styrene. When the cyclic olefin resin is a ternary copolymer of a cyclic olefin, a chain olefin, and an aromatic compound having a vinyl group, the content ratio of structural units derived from the chain olefin is that of the copolymer The content of structural units derived from an aromatic compound having a vinyl group is usually 5 to 80 mol% based on the total structural units, and is usually 5 to 80 mol% based on the total structural units of the copolymer It is. Such terpolymers have the advantage of being able to use relatively low amounts of expensive cyclic olefins in their preparation.

  In the present invention, the first retardation layer can be obtained by using, as a substrate, a stretched film obtained by stretching a polymer film having a specific structure and having the optical properties represented by the above formulas (3) and (4). Alternatively, it may double as the second retardation layer.

[First retardation layer]
The first retardation layer preferably has optical properties represented by Formula (1), Formula (3) and Formula (4), and more preferably the optical properties represented by Formula (1-1) Have. The in-plane retardation value Re (550) can be adjusted by the same method as the adjustment method of the in-plane retardation value of the retardation layer.
200 nm <Re (550) <320 nm (1)
220 nm <Re (550) <300 nm (1-1)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
The Re (450) / Re (550) [formula (3)] of the first retardation layer is preferably 0.95 or less, more preferably 0.90 or less, and usually 0.60 or more. And preferably 0.70 or more.
The Re (650) / Re (550) [formula (4)] of the first retardation layer is preferably 1.01 or more, and usually 1.40 or less, preferably 1.30 or less.

  The first retardation layer is preferably a coating layer formed by polymerizing one or more polymerizable liquid crystals. The coating layer is composed of a polymer in which the alignment is fixed by polymerizing in a state where the polymerizable liquid crystal is oriented in the in-plane direction of the coating layer. More preferably, the first retardation layer is a coating layer formed by polymerizing the polymerizable liquid crystal (I).

  When the first retardation layer is a stretched film, the thickness is usually 300 μm or less, preferably 5 μm or more and 100 μm or less. In the case of a layer formed by polymerizing a polymerizable liquid crystal, the thickness of the first retardation layer is usually 20 μm or less, preferably 5 μm or less, more preferably 0.5 μm to 3 μm. is there. The thickness of the first retardation layer can be determined by measurement with an interference film thickness meter, a laser microscope or a stylus film thickness meter.

[Second retardation layer]
The second retardation layer has optical properties represented by Formula (2), Formula (3) and Formula (4), and more preferably has optical properties represented by Formula (2-1).
100 nm <Re (550) <160 nm (2)
110 nm <Re (550) <150 nm (2-1)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
The Re (450) / Re (550) [formula (3)] of the second retardation layer is preferably 0.95 or less, more preferably 0.90 or less, and usually 0.60 or more. is there.
The Re (650) / Re (550) [formula (4)] of the second retardation layer is preferably 1.01 or more, and usually 1.40 or less, preferably 1.30 or less.

  The second retardation layer is preferably a coating layer formed by polymerizing one or more polymerizable liquid crystals. The coating layer is composed of a polymer in which the alignment is fixed by polymerizing in a state where the polymerizable liquid crystal is oriented in the in-plane direction of the coating layer. The second retardation layer is more preferably a coating layer formed by polymerizing the polymerizable liquid crystal (I).

  When the second retardation layer is a stretched film, the thickness is usually 300 μm or less, preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. In the case of a layer formed by polymerizing a polymerizable liquid crystal, the thickness of the second retardation layer is usually 10 μm or less, preferably 5 μm or less, more preferably 0.3 μm to 3 μm. is there. The thickness of the second retardation layer can be determined in the same manner as the first retardation layer. The thickness of each of the first retardation layer and the second retardation layer is preferably 5 μm or less.

[Third phase difference layer]
The in-plane retardation value Re (550) of the third retardation layer is usually in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm. The thickness direction retardation value Rth is usually in the range of -10 to -300 nm, preferably in the range of -20 to -200 nm. The in-plane retardation value Re (550) and the retardation value Rth in the thickness direction can be adjusted in the same manner as the retardation layer.

In addition, the third retardation layer may have the optical properties represented by Formulas (6) and (7). Such optical properties can be obtained by the same method as the above retardation layer.
Re (450) / Re (550) ≧ 1.00 (6)
1.00 ≧ Re (650) / Re (550) (7)

  The third retardation layer is preferably a coating layer formed by polymerizing one or more polymerizable liquid crystals. The coating layer is composed of a polymer in which the alignment is fixed by polymerizing the polymerizable liquid crystal in a state in which the polymerizable liquid crystal is aligned in a direction perpendicular to the layer. When the third retardation layer has optical properties represented by the formulas (6) and (7), there is no need to polymerize the polymerizable liquid crystal (I), and polymerization as generally marketed Liquid crystal compounds may be used.

<Base material>
The retardation film of the present invention preferably comprises a substrate. Examples of the substrate include the same as those described above.

  The surface of the base on which the alignment film, the first retardation layer, the second retardation layer, and the third retardation layer are formed is subjected to surface treatment before forming the alignment film or the retardation layer. You may As a method of surface treatment, a method of treating the surface of a substrate with corona or plasma under vacuum or atmospheric pressure, a method of laser treating a substrate surface, a method of ozonizing a substrate surface, and a method of saponifying a substrate surface A method of flame treatment or a method of flame treatment of a substrate surface, a method of primer treatment of applying a coupling agent to the substrate surface, radiation after attaching a reactive monomer or a polymer having reactivity to the substrate surface The graft polymerization method etc. which are made to react by irradiating a plasma or an ultraviolet-ray etc. are mentioned. Among them, a method in which the substrate surface is subjected to corona or plasma treatment under vacuum or at atmospheric pressure is preferable.

  As a method of surface treatment of a substrate by corona or plasma, a method of placing a substrate between opposed electrodes under pressure near atmospheric pressure, generating corona or plasma, and treating the surface of the substrate A method of flowing a gas between opposed electrodes, plasmatizing a gas between the electrodes, and blowing a plasmatized gas onto a substrate, and generating glow discharge plasma under a low pressure condition to treat the surface of the substrate How to do it.

  Among them, under pressure near atmospheric pressure, a substrate is placed between opposed electrodes, corona or plasma is generated to perform surface treatment of the substrate, or a gas is allowed to flow between the opposed electrodes, A preferred method is to plasmatize the gas between them and spray the plasmatized gas onto the substrate. Such surface treatment by corona or plasma is usually performed by a commercially available surface treatment apparatus.

  The substrate is preferably a substrate having high transparency and small retardation. It is preferable that the base material be colorless in that it is easy to control a * within the range shown by Formula (6) and b * within the range shown by Formula (7). Examples of the substrate having high transparency and small phase difference include cellulose ester films having no phase difference, such as Zerotack (registered trademark) (Konica Minolta Opto Co., Ltd.), Ztack (Fuji Film Co., Ltd.), and the like. In addition, an unstretched cyclic olefin-based resin substrate is also preferable. As a transparency index, a substrate having a total light transmittance of 80% or more is preferable, and as a retardation value, a front retardation value is preferably 10 nm or less.

In the present invention, the first position can be obtained by using, as a base material, a stretched film obtained by stretching a polymer film having a specific structure, which has the optical properties represented by the formulas (3) and (4). It may double as the retardation layer or the second retardation layer.

Further, as a preferred embodiment of the present invention, the first retardation layer of 5 μm or less or / and the second retardation layer or / and the second retardation layer or / and the second retardation layer or / It is more preferable from the viewpoint of thinning since only the retardation layer of the above can be applied.

  In addition, the surface of the base on which the alignment film, the first retardation layer, the second retardation layer, and the third retardation layer are not formed may be subjected to hard coating treatment, antistatic treatment, etc. . In addition, additives such as ultraviolet light absorbers may be included as long as the performance is not affected.

  The thickness of the substrate is usually 5 to 300 μm, preferably 10 to 200 μm, because when the thickness is too thin, the strength tends to decrease and the processability tends to be poor.

<Polymerizable liquid crystal composition>
In a layer (retardation layer) formed by polymerizing a polymerizable liquid crystal, a composition containing one or more polymerizable liquid crystals (hereinafter sometimes referred to as a polymerizable liquid crystal composition) is used as a substrate. It forms by apply | coating on alignment film, a protective layer, or retardation layer, and polymerizing the polymeric liquid crystal in the obtained coating film.

The polymerizable liquid crystal composition usually contains a solvent, and the solvent is preferably a solvent capable of dissolving the polymerizable liquid crystal, and is more preferably a solvent inert to the polymerization reaction of the polymerizable liquid crystal.
Specific solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether and phenol; ester solvents such as ethyl acetate and butyl acetate; acetone, methyl ethyl ketone, Ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, methyl amyl ketone, methyl isobutyl ketone, N-methyl-2-pyrrolidinone; non-chlorinated aliphatic hydrocarbon solvents such as pentane, hexane, heptane; toluene, xylene, etc. Non-chlorinated aromatic hydrocarbon solvents; nitrile solvents such as acetonitrile; ether solvents such as propylene glycol monomethyl ether, tetrahydrofuran, dimethoxyethane and the like; And chloroform, chlorinated hydrocarbon solvents such as chlorobenzene; include. These other solvents may be used alone or in combination.

  The content of the solvent in the polymerizable liquid crystal composition is usually preferably 10 parts by mass to 10000 parts by mass, and more preferably 50 parts by mass to 5000 parts by mass with respect to 100 parts by mass of the solid content. The solid content means the total of the components from which the solvent is removed from the polymerizable liquid crystal composition.

  Coating of the polymerizable liquid crystal composition is usually performed by a coating method such as spin coating method, extrusion method, gravure coating method, die coating method, slit coating method, bar coating method, applicator method, or flexo method. It is carried out by a known method such as a method. After application, a dry film is generally formed by removing the solvent under the condition that the polymerizable liquid crystal contained in the obtained coating film does not polymerize. As a drying method, a natural drying method, a ventilation drying method, a heating drying and a reduced pressure drying method may be mentioned.

<Alignment film>
The alignment film in the present invention has an alignment regulating force to align the polymerizable liquid crystal in a desired direction.
It is preferable that the alignment film has solvent resistance which is not dissolved by application of the polymerizable liquid crystal composition and the like, and has heat resistance in heat treatment for removal of the solvent and alignment of the polymerizable liquid crystal. Examples of such an alignment film include an alignment film containing an alignment polymer, a photo alignment film, and a groove alignment film in which a concavo-convex pattern and a plurality of grooves are formed on the surface and aligned.

  Examples of orientation polymers include polyamides and gelatins having an amide bond in the molecule, polyamic acid which is a polyimide having an imide bond in the molecule and its hydrolyzate, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, Polyethylenimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic esters are included. Among them, polyvinyl alcohol is preferred. Two or more orientation polymers may be used in combination.

  In an alignment film containing an alignment polymer, a composition in which the alignment polymer is dissolved in a solvent (hereinafter sometimes referred to as an alignment polymer composition) is usually applied to a substrate to remove the solvent, or alignment Is obtained by applying the base polymer composition to a substrate, removing the solvent and rubbing (rubbing method).

  As the solvent, alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, Ester solvents such as propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, cyclohexanone, methyl amyl ketone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile, ethers such as tetrahydrofuran and dimethoxyethane Solvents, and, chloroform, chlorinated hydrocarbon solvents such as chlorobenzene. These solvents may be used alone or in combination of two or more.

  The concentration of the orienting polymer in the orientating polymer composition may be in the range in which the orienting polymer material can be completely dissolved in the solvent, but preferably 0.1 to 20% in terms of solid content with respect to the solution, 0 About 1 to 10% is more preferable.

  A commercially available alignment film material may be used as it is as an alignment polymer composition. Examples of commercially available alignment film materials include Sun Ever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optomer (registered trademark, manufactured by JSR Corporation), and the like.

  As a method of applying the oriented polymer composition to a substrate, spin coating method, extrusion method, gravure coating method, die coating method, slit coating method, bar coating method, coating method such as applicator method, flexo method And other known methods such as printing methods. In the case of producing the present retardation film by a roll-to-roll type continuous manufacturing method described later, a printing method such as a gravure coating method, a die coating method or a flexo method is usually adopted as the coating method.

  Examples of the method for removing the solvent contained in the oriented polymer composition include a natural drying method, a ventilation drying method, a heat drying and a reduced pressure drying method.

  Rubbing can be performed as necessary to impart an alignment regulating force to the alignment film (rubbing method).

  As a method of imparting alignment control force by rubbing method, it was formed on the surface of a substrate by applying an orienting polymer composition to a substrate and annealing it on a rotating rubbing roll on which a rubbing cloth is wound and rotating. The method of making the film | membrane of an oriented polymer contact is mentioned.

  In order to impart an alignment regulating force to the alignment film, photoalignment can be performed as needed (photoalignment method).

  In the photo alignment film, a composition containing a polymer or monomer having a photo reactive group and a solvent (hereinafter sometimes referred to as “a composition for forming a photo alignment film”) is applied to a substrate, and light ( Preferably, it is obtained by irradiating polarized UV). The photo alignment film is more preferable in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the light to be irradiated.

  The photoreactive group refers to a group that generates liquid crystal alignment ability by light irradiation. Specific examples thereof include groups involved in the photoreaction that is the source of liquid crystal alignment ability such as alignment induction or isomerization reaction of molecules generated by light irradiation, dimerization reaction, photocrosslinking reaction or photodecomposition reaction. Among them, a group involved in a dimerization reaction or a photocrosslinking reaction is preferable in that it is excellent in the orientation. As a photoreactive group, a group having an unsaturated bond, particularly a double bond, is preferable, and a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), a nitrogen-nitrogen double bond Particularly preferred is a group having at least one selected from the group consisting of a heavy bond (NNN bond) and a carbon-oxygen double bond (C = O bond).

  Examples of the photoreactive group having a C = C bond include vinyl group, polyene group, stilbene group, stilbazole group, stilbazolium group, chalcone group and cinnamoyl group. Examples of photoreactive groups having a C = N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. As a photoreactive group having a C = O bond, benzophenone group, coumarin group, anthraquinone group and maleimide group can be mentioned. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group or a halogenated alkyl group.

  Among them, a photoreactive group involved in the photodimerization reaction is preferable, the amount of polarized light necessary for photoalignment is relatively small, and a photoalignment film excellent in thermal stability and temporal stability is easily obtained. Cinnamoyl and chalcone are preferred. As the polymer having a photoreactive group, those having a cinnamoyl group which has a cinnamic acid structure at the end of the polymer side chain are particularly preferable.

  By applying the composition for forming a photoalignment film on a substrate, a photoalignment induction layer can be formed on the substrate. The solvent contained in the composition may be the same as the solvent contained in the above-mentioned alignment polymer composition, and can be appropriately selected according to the solubility of the polymer or monomer having a photoreactive group. .

  The content of the polymer or monomer having a photoreactive group in the composition for forming a photoalignment film can be appropriately adjusted depending on the type of polymer or monomer and the thickness of the target photoalignment film, but at least 0.2% by mass Preferably, the range of 0.3 to 10% by mass is more preferable. The composition for forming a photoalignment film may contain a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer within a range that the characteristics of the photoalignment film are not significantly impaired.

  As a method of apply | coating the composition for photo-alignment film formation to a base material, the method similar to the method of apply | coating an oriented polymer composition to a base material is mentioned. As a method of removing a solvent from the composition for photo-alignment film formation apply | coated, the same method as the method of removing a solvent from alignment polymer composition is mentioned, for example.

  In order to irradiate polarized light, the composition for forming a photo alignment film coated on a substrate is directly irradiated with polarized UV from the substrate side even if it is irradiated with polarized UV directly to the one from which the solvent is removed, and the polarized light is transmitted. It may be in the form of irradiation. Moreover, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in the wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength of 250 to 400 nm is particularly preferable. Examples of light sources used for the polarized light irradiation include xenon lamps, high pressure mercury lamps, ultra high pressure mercury lamps, metal halide lamps, ultraviolet light lasers such as KrF and ArF, etc. High pressure mercury lamps, ultra high pressure mercury lamps and metal halides Lamps are more preferred. These lamps are preferable because the emission intensity of ultraviolet light with a wavelength of 313 nm is large. Polarized UV can be illuminated by illuminating the light from the light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thomson, Glan-Teller, or a wire grid type polarizer can be used.

  Note that when rubbing or polarized irradiation is performed, masking may be performed to form a plurality of regions (patterns) having different liquid crystal alignment directions.

  The glue alignment film is a film in which liquid crystal alignment can be obtained by a concavo-convex pattern or a plurality of grooves on the film surface. H. V. According to Kenel et al., When liquid crystal molecules are placed on a substrate having a plurality of equally spaced linear grooves (grooves), the liquid crystal molecules are aligned in the direction along the groove ( Physical Review A24 (5), 2713, 1981).

  As a specific example to obtain a glue alignment film, after exposure through a mask for exposure having a slit of a periodic pattern shape on the photosensitive polyimide surface, development and rinsing are performed to remove unnecessary polyimide film A method of forming a pattern, a method of forming a UV curable resin layer on a plate-like master having grooves on the surface, transferring the resin layer to a substrate film and then curing, conveying a substrate film having a UV cured resin layer formed thereon And a method of pressing a roll-like master having a plurality of grooves against the surface of the UV curable resin layer to form asperities and then curing, and the like, as described in JP-A-6-34976 and JP-A-2011-242743. A method etc. can be used.

  Among the above methods, a method is preferable in which a roll-shaped master having a plurality of grooves is pressed against the surface of the UV curable resin layer to form asperities and then cure. From the viewpoint of durability, stainless steel (SUS) can be used as the roll-shaped master.

As the UV curing resin, a polymer of a monofunctional acrylate, a polymer of a polyfunctional acrylate, or a polymer of a mixture thereof can be used.
The monofunctional acrylate is a group selected from the group consisting of an acryloyloxy group (CH2 = CH-COO-) and a methacryloyloxy group (CH2 = C (CH3) -COO-) (hereinafter referred to as (meth) acryloyloxy group) Or a compound having one in the molecule.

  The monofunctional acrylate having one (meth) acryloyloxy group includes alkyl (meth) acrylates having 4 to 16 carbon atoms, β-carboxyalkyl (meth) acrylates having 2 to 14 carbon atoms, and alkylation having 2 to 14 carbon atoms There may be mentioned phenyl (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, isobonyl (meth) acrylate and the like.

  The polyfunctional acrylate is usually a compound having 2 to 6 (meth) acryloyloxy groups in the molecule.

  As a bifunctional acrylate having two (meth) acryloyloxy groups, 1,3-butanediol di (meth) acrylate; 1,3-butanediol (meth) acrylate; 1,6-hexanediol di (meth) acrylate Ethylene glycol di (meth) acrylate; diethylene glycol di (meth) acrylate; neopentyl glycol di (meth) acrylate; triethylene glycol di (meth) acrylate; tetraethylene glycol di (meth) acrylate; polyethylene glycol diacrylate; bisphenol A Bis (acryloyloxyethyl) ethers; ethoxylated bisphenol A di (meth) acrylates; propoxylated neopentyl glycol di (meth) acrylates; ethoxylated neopentyl glycols And di (meth) acrylate and 3-methyl-pentanediol di (meth) acrylate.

As a polyfunctional acrylate having 3 to 6 (meth) acryloyloxy groups,
Trimethylolpropane tri (meth) acrylate; pentaerythritol tri (meth) acrylate; tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; ethoxylated trimethylolpropane tri (meth) acrylate; propoxylated trimethylolpropane tri ( Meta) acrylate; pentaerythritol tetra (meth) acrylate; dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate; tripentaerythritol tetra (meth) acrylate; tripentaerythritol penta (meth) acrylate; Erythritol hexa (meth) acrylate; tripentaerythritol hepta (meth) acrylate; tripentaerythritol o Data (meth) acrylate;
A reaction product of pentaerythritol tri (meth) acrylate and an acid anhydride; a reaction product of dipentaerythritol penta (meth) acrylate and an acid anhydride;
Reactant of tripentaerythritol hepta (meth) acrylate with acid anhydride;
Caprolactone modified trimethylolpropane tri (meth) acrylate; caprolactone modified pentaerythritol tri (meth) acrylate; caprolactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; caprolactone modified pentaerythritol tetra (meth) acrylate; caprolactone modified Dipentaerythritol penta (meth) acrylate; caprolactone modified dipentaerythritol hexa (meth) acrylate; caprolactone modified tripentaerythritol tetra (meth) acrylate; caprolactone modified tripentaerythritol penta (meth) acrylate; caprolactone modified tripentaerythritol hexa (meth) ) Acrylate; caprolactone modified tripentaellis Tall hepta (meth) acrylate; caprolactone modified tripentaerythritol octa (meth) acrylate; reaction product of caprolactone modified pentaerythritol tri (meth) acrylate and acid anhydride; caprolactone modified dipentaerythritol penta (meth) acrylate and acid anhydride And caprolactone-modified tripentaerythritol hepta (meth) acrylate and an acid anhydride. In addition, in the specific example of the polyfunctional acrylate shown here, (meth) acrylate means an acrylate or a methacrylate. Moreover, caprolactone modification means that the ring-opened body or ring-opening polymer of caprolactone is introduce | transduced between the alcohol origin site | part of a (meth) acrylate compound, and a (meth) acryloyloxy group.

A commercial item can also be used for this polyfunctional acrylate.
As such commercial products, A-DOD-N, A-HD-N, A-NOD-N, APG-100, APG-200, APG-400, A-GLY-9E, A-GLY-20E, A- TMM-3, A-TMPT, AD-TMP, ATM-35E, A-TMMT, A-9550, A-DPH, HD-N, NOD-N, NPG, TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.), "ARONIX M-220 "," M-325 "," M-240 "," M-270 "," M-309 "," M-310 "," M-321 "," M- 350 "," M-360 "," M-305 "," M-306 "," M-450 "," M-451 "," M-408 "," M-400 " , "M-402", "M-403", and "M-404", "M-" 05 "," M-406 "(made by Toa Gosei Co., Ltd.)," EBECRYL11 "," 145 "," 150 "," 40 "," 140 "," 180 ", DPGDA, HDDA, TPGDA, HPNDA, PETIA, PETRA, TMPTA, TMPEOTA, DPHA, EBECRYL series (manufactured by Daicel-Cytec Co., Ltd.) and the like can be mentioned.

  As the unevenness of the glue alignment film, the width of the projections is preferably 0.05 to 5 μm, the width of the depressions is preferably 0.1 to 5 μm, and the depth of the unevenness is preferably 2 μm or less. Is preferably 0.01 to 1 μm or less. Within this range, liquid crystal alignment with small alignment disorder can be obtained.

  The thickness of the alignment film is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm, more preferably 500 nm or less, and still more preferably in the range of 10 nm to 500 nm.

The liquid crystal alignment of the polymerizable liquid crystal is controlled by the properties of the alignment film and the polymerizable liquid crystal.
For example, if the alignment film is a material that expresses horizontal alignment control force as alignment control force, the polymerizable liquid crystal can form horizontal alignment or hybrid alignment, and if it is a material that expresses vertical alignment control force, polymerization is possible. The liquid crystal can form vertical alignment or tilt alignment.
The alignment control force can be arbitrarily adjusted depending on the surface state and the rubbing condition when the alignment film is formed of the alignment polymer, and when the alignment film is formed of the photoalignment polymer, the polarization irradiation condition is It is possible to adjust arbitrarily by etc. The liquid crystal alignment can also be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal.

  The polymerization of the polymerizable liquid crystal can be carried out by a known method of polymerizing a compound having a polymerizable functional group. Specifically, thermal polymerization and photopolymerization can be mentioned, and from the viewpoint of easiness of polymerization, photopolymerization is preferable. In the case of polymerizing a polymerizable liquid crystal by photopolymerization, a polymerizable liquid crystal composition containing a photopolymerization initiator is applied and dried, and then the polymerizable liquid crystal in the dried film obtained is brought into a liquid crystal phase state, and then the liquid crystal state It is preferable to carry out photopolymerization while holding the

  Photopolymerization is usually carried out by irradiating the dry film with light. The light to be irradiated is appropriately selected according to the type of the photopolymerization initiator contained in the dry film, the type of the polymerizable liquid crystal (in particular, the type of the photopolymerizable group possessed by the polymerizable liquid crystal) and the amount thereof. And actinic radiation may be selected from the group consisting of visible light, ultraviolet light and laser light. Among them, ultraviolet light is preferred in that it is easy to control the progress of the polymerization reaction, and that it can be used widely as an apparatus for photopolymerization, so that it can be photopolymerized by ultraviolet light, It is preferable to select the type of the polymerizable liquid crystal and the photopolymerization initiator. The polymerization temperature can also be controlled by light irradiation while cooling the dried film by an appropriate cooling means at the time of polymerization. If the polymerization of the polymerizable liquid crystal is carried out at a lower temperature by employing such a cooling means, a retardation layer can be appropriately formed even if the substrate has a relatively low heat resistance. At the time of photopolymerization, a patterned retardation layer can also be obtained by performing masking or development.

  The polymerizable liquid crystal composition preferably contains one or more leveling agents. The leveling agent has the function of adjusting the flowability of the polymerizable liquid crystal composition and making the coated film obtained by applying the polymerizable liquid crystal composition flatter. Specifically, the surfactant is exemplified. Be The leveling agent is preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component, a leveling agent containing a fluorine atom-containing compound as a main component, and a leveling agent containing a silicone compound as a main component. The leveling agent which has a polyacrylate compound as a main component and the leveling agent which has a fluorine atom containing compound as a main component are preferable.

  As a leveling agent which has a polyacrylate compound as a main component, "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-358N", " BYK-361N "," BYK-380 "," BYK-381 "and" BYK-392 "[BYK Chemie] are mentioned.

  As a leveling agent which has a fluorine atom containing compound as a main component, "Megafuck (registered trademark) R-08", the same "R-30", the same "R-90", the same "F-410", the same "F -411 "," F-443 "," F-445 "," F-470 "," F-471 "," F-477 "," F-479 ", and" F- 482 "and" F-483 "(DIC Corporation);" Surflon (registered trademark) S-381 "," S-382 "," S-383 ", and" S-393 ", and" F-483 " “SC-101”, “SC-105”, “KH-40” and “SA-100” (AGC Seimi Chemical Co., Ltd.); “E1830”, “E5844” [Daikin Fine Chemical Research Institute]; F-top EF 301, F-top EF 303, F-top EF 51 "and" Eftop EF352 "[Mitsubishi Materials Electronic Chemicals Co., Ltd.] and the like.

  When the polymerizable liquid crystal composition contains a leveling agent, the content thereof is preferably 0.01 parts by mass or more and 5 parts by mass or less, and 0.05 parts by mass or more and 5 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal. The following is more preferable, and 0.05 to 3 parts by mass is more preferable. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal, and the obtained polarizing layer tends to be smoother. When the content of the leveling agent with respect to the polymerizable liquid crystal is within the above range, unevenness tends to be less likely to occur in the obtained retardation layer.

  The polymerizable liquid crystal composition preferably contains one or more polymerization initiators. The polymerization initiator is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal, and a photopolymerization initiator is preferred in that the polymerization reaction can be initiated under lower temperature conditions. Specifically, a photopolymerization initiator capable of generating an active radical or an acid by the action of light is mentioned, and among them, a photopolymerization initiator which generates a radical by the action of light is preferable.

  Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acyl phosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts.

  The benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether.

  As a benzophenone compound, benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3 ', 4,4'-tetra (tert-butylperoxycarbonyl) benzophenone And 2,4,6-trimethylbenzophenone.

  As the alkyl phenone compound, diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane -1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1- [1 4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propan-1-one Oligomers are mentioned.

  The acyl phosphine oxide compounds include 2,4,6-trimethyl benzoyl diphenyl phosphine oxide and bis (2,4,6-trimethyl benzoyl) phenyl phosphine oxide.

  As a triazine compound, 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2 -(5-Methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1,3 5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine and 2,4-bis (trichloromethyl) -6-[ - (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  A commercially available thing can be used for a polymerization initiator. Commercially available polymerization initiators include “Irgacure (registered trademark) 907”, “Irgacure (registered trademark) 184”, “Irgacure (registered trademark) 651”, “Irgacure (registered trademark) 819”, “Irgacure ( "250", "IRGACURE (registered trademark) 369" (Ciba Japan Co., Ltd.), "SEIKOL (registered trademark) BZ", "SEIKOL (registered trademark) Z", "SEIKOL (registered trademark) BEE" ( SEIKO CHEMICAL CO., LTD .; "Kayacure (registered trademark) BP 100" (Nippon Kayaku Co., Ltd.); "Kayacure (registered trademark) UVI-6992" (manufactured by Dow); "Adeka Optomer SP-152" "" Adeka Optomer SP-170 "(ADEKA Corporation);" TAZ-A "," TAZ-PP "(day Siber Hegner Ltd.); and "TAZ-104" (Sanwa Chemical Co., Ltd.).

  When the polymerizable liquid crystal composition contains a polymerization initiator, the content thereof can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal contained in the composition, but the content is 100 parts by mass of the polymerizable liquid crystal. 0.1 to 30 parts by mass is preferable, 0.5 to 10 parts by mass is more preferable, and 0.5 to 8 parts by mass is more preferable. If the content of the polymerizable initiator is within this range, it is possible to polymerize without disturbing the alignment of the polymerizable liquid crystal. In addition, the small content of the polymerization initiator suppresses the coloration caused by the decomposition product of the polymerization initiator, a * is in the range of formula (6), and b * is in the range of formula (7). Is easy and preferable.

  When the polymerizable liquid crystal composition contains a photopolymerization initiator, the composition may further contain a photosensitizer. As the photosensitizer, xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone, 2-isopropylthioxanthone and the like); anthracene compounds such as anthracene and alkoxy group-containing anthracene (for example, dibutoxyanthracene and the like); It includes phenothiazine and rubrene.

  When the polymerizable liquid crystal composition contains a photopolymerization initiator and a photosensitizer, the polymerization reaction of the polymerizable liquid crystal contained in the composition can be further promoted. The amount of the photosensitizer used can be appropriately adjusted according to the type and amount of the photopolymerization initiator and the polymerizable liquid crystal, but is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal, 0.5-10 mass parts is more preferable, and 0.5-8 mass parts is further more preferable. In addition, the small content of the photosensitizer suppresses the coloration caused by the photosensitizer, a * is in the range of Formula (6), and b * is in the range of Formula (7). It is easy and preferable.

  In order to allow the polymerization reaction of the polymerizable liquid crystal to progress more stably, the polymerizable liquid crystal composition may contain an appropriate amount of polymerization inhibitor, which makes it easy to control the progress of the polymerization reaction of the polymerizable liquid crystal. Become.

  Examples of the polymerization inhibitor include radical scavengers such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (for example, butyl catechol etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical and the like Thiophenols; β-naphthylamines and β-naphthols.

  When the polymerizable liquid crystal composition contains a polymerization inhibitor, the content thereof can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal, the amount of the photosensitizer used, etc. 0.1-30 mass parts is preferable with respect to part, 0.5-10 mass parts is more preferable, 0.5-8 mass parts is further more preferable. If the content of the polymerization inhibitor is within this range, it is possible to polymerize without disturbing the alignment of the polymerizable liquid crystal.

  When manufacturing this retardation film, the order which forms a 1st phase difference layer, a 2nd phase difference layer, and a 3rd phase difference layer is arbitrary.

A first retardation layer is formed on the substrate with or without the alignment film, and a second retardation layer is formed on the first retardation layer with or without the alignment film. May form. In this case, the present retardation film is provided with the first retardation layer on the substrate via the orientation film or without the orientation film, and the orientation film is provided on the first retardation layer. The second retardation layer is provided without using the alignment film or the alignment film. At this time, a protective layer may be present between the first retardation layer and the second retardation layer.
A second retardation layer is formed on the substrate with or without the alignment film, and a first retardation layer is formed on the second retardation layer with or without the alignment film. May be formed. In this case, the present retardation film is provided with a second retardation layer on a substrate, with or without an alignment film, and the alignment film is provided on the second retardation layer. It becomes the structure provided with the 1st phase difference layer, without passing through via an orientation film. At this time, a protective layer may be present between the first retardation layer and the second retardation layer.

A first retardation layer is formed on one side of the substrate with or without an alignment film, and a second retardation layer is formed on the first retardation layer with or without the alignment film. A retardation layer may be formed.
In this case, the present retardation film is provided with the first retardation layer on one surface of the substrate with or without the alignment film, and the alignment film is formed on the first retardation layer. The second retardation layer is provided via or without the alignment film.
A second retardation layer is formed on one side of the substrate with or without the alignment film, and a first retardation layer is formed on the second retardation layer with or without the alignment film. A retardation layer may be formed, and the second retardation layer may be formed on the other surface of the substrate with or without the alignment film. In this case, the present retardation film is provided with a second retardation layer on one surface of the substrate with or without the alignment film, and the alignment is performed on the second retardation layer. A first retardation layer is provided via a film or not via an alignment film, and a second retardation is provided on the other surface of the substrate via the alignment film or not via an alignment film. It becomes the composition provided with the layer.

  In addition, the first retardation layer and the second retardation layer respectively produced may be transferred to a substrate to be transferred using an adhesive or an adhesive, and the polarizing plate may be formed via the adhesive or adhesive. The formation of the first retardation layer and the formation of the second retardation layer through an adhesive or an adhesive can be said to be a preferable form in that a very thin and high-performance circularly polarizing plate can be produced.

  Further, in view of thinning of the optical film, the thickness of the layer including at least the first retardation layer and the second retardation layer in the present invention is preferably 60 μm or less, more preferably 40 μm or less, More preferably, it is 20 μm or less.

<Protective layer>
The protective layer is usually an acrylic oligomer or polymer comprising polyfunctional acrylate (methacrylate), urethane acrylate, polyester acrylate, epoxy acrylate etc., polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl pyrrolidone, starches, methyl cellulose, carboxy It is preferable to form from the composition for protective layer formation containing water-soluble polymers, such as methylcellulose and sodium alginate, and a solvent.

  Examples of the solvent contained in the composition for forming a protective layer include the same solvents as those described above, and among them, at least one solvent selected from the group consisting of water, an alcohol solvent and an ether solvent forms a protective layer. It is preferable in that it does not dissolve the layer. Alcohol solvents include methanol, ethanol, butanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether. Ether solvents include ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. Among them, ethanol, isopropyl alcohol, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are preferable.

  The thickness of the protective layer is usually 20 μm or less. 0.5 micrometer or more and 10 micrometers or less are preferable, and, as for the thickness of a protective layer, 1 micrometer or more and 5 micrometers or less are more preferable. The thickness of the protective layer can usually be determined by measurement with an interference film thickness meter, a laser microscope or a stylus film thickness meter.

Then, the method to manufacture this retardation film continuously is demonstrated. As a suitable method for producing such a retardation film continuously, there is a roll to roll method. Here, although the manufacturing method of the phase difference layer formed by polymerizing a polymerizable liquid crystal is demonstrated, it changes to the phase difference layer formed by polymerizing a polymerizable liquid crystal, and the phase difference layer which consists of stretched films. In this case, “to apply the polymerizable liquid crystal composition” in the following production process may be read as “to laminate the stretched film”.
Moreover, although the manufacturing method of a typical structure is illustrated below, another structure may be implemented according to the following manufacturing method.

(1) preparing a roll in which the base material is wound around a core;
(2) Continuously feeding out the substrate from the roll,
(3) forming an alignment film continuously on the substrate,
(4) applying a polymerizable liquid crystal composition on the alignment film, and continuously forming a first retardation layer;
(5) forming a protective layer continuously on the first retardation layer obtained in (4) above,
(6) forming an alignment film continuously on the protective layer obtained in the above (5);
(7) A step of applying a polymerizable liquid crystal composition on the alignment film obtained in the above (6) and continuously forming a second retardation layer,
(8) A method may be mentioned in which the steps of obtaining the second roll are sequentially performed by winding the retardation film obtained continuously onto a second core. Steps (3), (5) and (6) may be omitted as necessary. In this case, “on the alignment film” in step (4) is “on the substrate”, The “protective layer obtained in the above (5)” in the step (6) corresponds to “the first retardation layer” and the “alignment film obtained in the above (6)” in the step (7) corresponds to “the first retardation layer”. It is replaced with the first retardation layer or the protective layer obtained in (5) above. Moreover, in order to suppress the wrinkles and curl at the time of conveyance, you may bond a protective film at the time of film conveyance in each process.

Also,
(1a) preparing a roll in which the base material is wound around a core;
(2a) continuously delivering the substrate from the roll;
(3a) forming an alignment film continuously on the substrate,
(4a) applying a polymerizable liquid crystal composition on the alignment film to continuously form a second retardation layer;
(5a) forming a protective layer continuously on the second retardation layer obtained in (4a), (6a) continuously forming an alignment film on the protective layer obtained in (5a) Forming process,
(7a) applying a polymerizable liquid crystal composition on the alignment film obtained in the above (6a) to continuously form a first retardation layer;
(8a) A method is also possible in which the steps of obtaining the second roll are sequentially performed by winding the retardation film obtained continuously onto a second core. Steps (3a), (5a) and (6a) may be omitted as necessary. In this case, "on the alignment film" in step (4a) is "on the substrate", The “protective layer obtained in the above (5a)” in the step (6a) corresponds to “the second retardation layer”, and the “alignment film obtained in the above (6a)” in the step (7a) corresponds to “the second retardation layer”. The term “second retardation layer” or “the protective layer obtained in (5a)” is replaced. Moreover, in order to suppress the wrinkles and curl at the time of conveyance, you may bond a protective film at the time of film conveyance in each process.

Also,
(1b) preparing a roll in which the base material is wound around a core;
(2b) continuously feeding the substrate from the roll;
(3b) forming an alignment film continuously on the substrate,
(4b) applying a polymerizable liquid crystal composition on the alignment film to form a first retardation layer continuously;
(5b) forming an alignment film continuously on the surface of the base opposite to the first retardation layer obtained in (4b);
(6b) applying a polymerizable liquid crystal composition on the alignment film obtained in the above (5b) to continuously form a second retardation layer;
(7b) A method is also possible in which the steps of obtaining the second roll are sequentially performed by winding the retardation film obtained continuously onto a second core. Steps (3b) and (5b) may be omitted as necessary. In this case, “on the alignment film” in step (4b) corresponds to “on the base”, step (6b) “On the alignment film obtained in (5b)” in the above is replaced with “the surface of the substrate opposite to the first retardation layer obtained in (4b)”. Moreover, in order to suppress the wrinkles and curl at the time of conveyance, you may bond a protective film at the time of film conveyance in each process.

Also,
(1c) preparing a roll in which the transparent substrate is wound on a core;
(2c) continuously delivering the transparent substrate from the roll;
(3c) forming an alignment film continuously on the transparent substrate,
(4c) applying a polymerizable liquid crystal composition on the alignment film to continuously form a second retardation layer;
(5c) forming an alignment film continuously on the surface of the base opposite to the second retardation layer obtained in (4c),
(6c) applying a polymerizable liquid crystal composition on the alignment film obtained in the above (5c), and continuously forming a first retardation layer;
(7c) A method is also possible in which the steps of obtaining the second roll are sequentially performed by winding the retardation film obtained continuously onto a second core. Steps (3c) and (5c) may be omitted as necessary. In this case, “on the alignment film” in step (4c) corresponds to “on the base”, step (6c) “On the alignment film obtained in (5c) above” is replaced with “the surface of the substrate opposite to the second retardation layer obtained in (4c)”. Moreover, in order to suppress the wrinkles and curl at the time of conveyance, you may bond a protective film at the time of film conveyance in each process.

Also,
(1e) preparing a roll in which the substrate is wound around a core;
(2e) continuously feeding the substrate from the roll;
(3e) forming an alignment film continuously on the substrate,
(4e) applying a polymerizable liquid crystal composition on the alignment film to form a first retardation layer continuously;
(5e) a step of continuously forming a protective layer on the first retardation layer obtained in (4e), (6e) continuously forming an alignment film on the protective layer obtained in (5e) Forming process,
(7e) applying a polymerizable liquid crystal composition on the alignment film obtained in (6e) above, and continuously forming a second retardation layer;
(8e) forming an alignment film continuously on the surface of the substrate opposite to the first retardation layer obtained in (4e),
(9e) applying a polymerizable liquid crystal composition onto the alignment film obtained in (8e) above to form a third retardation layer continuously;
(10e) A method is also possible in which the steps of obtaining the second roll are sequentially performed by winding the retardation film obtained continuously onto a second core. Note that
Steps (3e), (5e) and (8e) may be omitted as necessary, in which case
“On the alignment film” in the step (4e) is “on the substrate”, “the protective layer obtained in the above (5e)” in the step (6e) is “on the above obtained in the above (4e) In the first retardation layer, “on the alignment film obtained in (8e) above” in the step (9e) is “the substrate surface opposite to the first retardation layer obtained in (4e) above” Replace with ". Moreover, in order to suppress the wrinkles and curl at the time of conveyance, you may bond a protective film at the time of film conveyance in each process. Moreover, in order to suppress the wrinkles and curl at the time of conveyance, you may bond a protective film at the time of film conveyance in each process.

<Adhesive agent>
An adhesive may be used to bond the first retardation layer, the second retardation layer, the polarizing plate, and the like. Examples of the pressure-sensitive adhesive include a pressure-sensitive adhesive, a water-based adhesive, and an active energy ray-curable adhesive.

  In general, as a pressure-sensitive adhesive, an acrylic monomer mixture mainly composed of (meth) acrylic acid ester and containing a small amount of (meth) acrylic monomer having a functional group is radically polymerized in the presence of a polymerization initiator. An acrylic pressure-sensitive adhesive which is obtained and contains an acrylic resin having a glass transition temperature Tg of 0 ° C. or less and a crosslinking agent is preferably used.

Among (meth) acrylic acid esters, acrylic acid alkyl esters are preferable, and among them, n-butyl acrylate, 2-methoxyethyl acrylate and ethoxymethyl acrylate are preferable.

  The (meth) acrylic monomer having a functional group to be another monomer component constituting the acrylic resin has one (meth) acryloyl group which is an olefinic double bond in the molecule, as well as a hydroxyl group, a carboxyl group, It is a compound having a polar functional group such as an amido group, an amino group or an epoxy group in the same molecule. Among them, acrylic monomers in which the acryloyl group is an olefinic double bond are preferable. As an example of the acrylic monomer having such a functional group, 2-hydroxyethyl acrylate is preferable as the one having a hydroxyl group, and acrylic acid is preferable as the one having a carboxyl group.

  The acrylic monomer mixture as a raw material of the acrylic resin further contains a monomer other than the above (meth) acrylic acid ester and the functional group-containing (meth) acrylic monomer (hereinafter sometimes referred to as "third monomer") You may Examples thereof include monomers having one olefinic double bond and at least one aromatic ring in the molecule, styrenic monomers, (meth) acrylates having alicyclic structures in the molecule, vinyl monomers And monomers having a plurality of (meth) acryloyl groups in the molecule.

  In particular, monomers having one olefinic double bond and at least one aromatic ring in the molecule are one of the preferred ones. Among them, 2-phenoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, 2- (o-phenylphenoxy) ethyl (meth) acrylate Preferably. Among these, 2-phenoxyethyl acrylate is more preferable.

  A monomer (third monomer) other than the (meth) acrylic acid ester and the (meth) acrylic monomer having a functional group may be used alone or in combination of two or more different types. The structural unit derived from these third monomers can be usually present in the range of 0 to 20% by weight, preferably 0 to 10% by weight, based on the entire acrylic resin.

  It is preferable that the acrylic resin which comprises an acrylic adhesive has the weight average molecular weights Mw of standard polystyrene conversion by gel permeation chromatography (GPC) in the range of 1 million-2 million. When the weight average molecular weight Mw is 1,000,000 or more, the adhesiveness under high temperature and high humidity is improved, and the possibility of floating or peeling between the glass substrate constituting the liquid crystal cell and the pressure sensitive adhesive layer is small. And reworkability tends to be improved. Also, if the weight average molecular weight Mw of the acrylic resin is 2,000,000 or less, the adhesive layer fluctuates following the dimensional change of the polarizing plate, so that the light leakage and color of the display It is preferable because unevenness tends to be suppressed. Furthermore, it is preferable that the molecular weight distribution represented by ratio Mw / Mn of weight average molecular weight Mw and number average molecular weight Mn exists in the range of 3-7.

  The acrylic resin contained in the acrylic pressure sensitive adhesive can be composed of only those having a relatively high molecular weight as described above, but can also be composed of a mixture with a different acrylic resin. As an example of the acrylic resin which can be mixed and used, the structural unit derived from the (meth) acrylic acid ester represented by the above formula (I) is used as a main component, and the weight average molecular weight is 50,000 to 300,000. There is something in the range.

  The above-mentioned acrylic resin which constitutes acrylic pressure sensitive adhesive can be manufactured by publicly known various methods, such as solution polymerization method, emulsion polymerization method, bulk polymerization method, suspension polymerization method, for example. In the production of this acrylic resin, a polymerization initiator is usually used. Examples of the polymerization initiator include an azo compound, an organic peroxide, an inorganic peroxide, and a redox initiator in which a peroxide and a reducing agent are used in combination. Among them, 2,2'-azobisisobutyronitrile, benzoyl peroxide, ammonium persulfate and the like are preferably used. The polymerization initiator is generally used in a proportion of about 0.001 to 5 parts by mass with respect to 100 parts by mass of the total of monomers serving as a raw material of the acrylic resin.

  The acrylic resin thus obtained is blended with a crosslinking agent to be used as a pressure sensitive adhesive. The crosslinking agent is a compound having in the molecule at least two functional groups capable of undergoing a crosslinking reaction with a structural unit derived from a monomer having a polar functional group in an acrylic resin, for example, an isocyanate compound, an epoxy compound, Examples include metal chelate compounds and aziridine compounds.

  Among these crosslinking agents, isocyanate compounds are preferably used. The isocyanate-based compound may be used in the form of an adduct obtained by reacting it with a polyol, a dimer thereof, a trimer thereof, etc. in addition to a compound itself having at least two isocyanato groups (-NCO) in its molecule. it can. Specific examples thereof include tolylene diisocyanate and an adduct obtained by reacting tolylene diisocyanate with a polyol, a dimer of tolylene diisocyanate, a trimer of tolylene diisocyanate, hexamethylene diisocyanate and hexamethylene diisocyanate as a polyol. These include adducts obtained by reaction, dimers of hexamethylene diisocyanate, and trimers of hexamethylene diisocyanate.

  The crosslinking agent is usually blended in a proportion of about 0.01 to 5 parts by mass, particularly 0.1 to 5 parts by mass, and further 0.2 to 3 parts by mass with respect to 100 parts by mass of the acrylic resin. It is preferable to mix | blend. If the blending amount of the crosslinking agent with respect to 100 parts by mass of the acrylic resin is 0.01 parts by mass or more, particularly 0.1 parts by mass or more, the durability of the pressure-sensitive adhesive layer tends to be improved.

  The pressure-sensitive adhesive can also contain other components, if necessary. Conductive fine particles such as metal fine particles, metal oxide fine particles or fine particles coated with metal or the like as other components which can be blended, ion conductive composition, ionic compound having organic cation or anion, silane Coupling agents, crosslinking catalysts, weathering stabilizers, tackifiers, plasticizers, softeners, dyes, pigments, inorganic fillers, resins other than the above acrylic resins, light diffusing fine particles such as organic beads, etc. may be mentioned. In addition, it is also useful that a UV-curable compound is compounded in a pressure-sensitive adhesive, and a pressure-sensitive adhesive layer is formed and then irradiated with ultraviolet light to be cured to form a harder pressure-sensitive adhesive layer.

  Each of these components constituting the pressure-sensitive adhesive is usually used as a pressure-sensitive adhesive composition in a state of being dissolved in an appropriate solvent such as ethyl acetate. The pressure-sensitive adhesive composition is applied onto a suitable substrate and dried to obtain a pressure-sensitive adhesive layer. Although some components do not dissolve in the solvent, they may be in the state of being dispersed in the system.

  As a method of forming a pressure-sensitive adhesive layer on the present retardation film, for example, a release film is used as a substrate, and the above-mentioned pressure-sensitive adhesive composition is applied to form a pressure-sensitive adhesive layer. The method of transferring to the surface of a film, the method of apply | coating the said adhesive composition directly on this retardation film surface, and forming an adhesive layer etc. are employ | adopted. Moreover, after forming an adhesive layer on the peeling film of 1 sheet, another release film can be further bonded on the adhesive layer, and it can also be set as a double-sided separator type | mold adhesive sheet. Such a double-sided separator type pressure-sensitive adhesive sheet peels off the release film on one side at a necessary time, and is bonded onto the present retardation film. Examples of commercially available double-sided separator-type pressure-sensitive adhesive sheets include non-carrier pressure-sensitive adhesive films and non-carrier pressure-sensitive adhesive sheets sold by Lintec Corporation and Nitto Denko Corporation.

  The release film is based on, for example, a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate, polypropylene or polyethylene, and the surface of the substrate to be bonded to the pressure-sensitive adhesive layer is treated with silicone. Such release treatment may be performed. Such release films are also referred to as separate films or separators.

  The thickness of the pressure-sensitive adhesive layer is preferably 5 to 50 μm, and more preferably 5 to 30 μm. By setting the thickness of the pressure-sensitive adhesive layer to 30 μm or less, the adhesiveness under high temperature and high humidity is improved, and the possibility of floating or peeling between the display and the pressure-sensitive adhesive layer tends to be low Reworkability also tends to improve. Further, by setting the thickness to 5 μm or more, even if the dimension of the polarizing plate bonded thereto changes, the pressure-sensitive adhesive layer changes to follow the dimensional change, so the durability against the dimensional change is improves.

  As a water-based adhesive, for example, using a polyvinyl alcohol resin or urethane resin as a main component, and a composition containing a crosslinking agent or a curable compound such as an isocyanate compound or an epoxy compound to improve adhesion It is common to do.

  When a polyvinyl alcohol-based resin is used as the main component of the aqueous adhesive, in addition to partially saponified polyvinyl alcohol and completely saponified polyvinyl alcohol, carboxyl group modified polyvinyl alcohol, acetoacetyl group modified polyvinyl alcohol, methylol group modified polyvinyl alcohol, and amino A modified polyvinyl alcohol resin such as a group modified polyvinyl alcohol may be used. An aqueous solution of such a polyvinyl alcohol-based resin is used as a water-based adhesive, and the concentration of the polyvinyl alcohol-based resin in the water-based adhesive is usually 1 to 10 parts by mass, preferably 100 parts by mass of water. 1 to 5 parts by mass.

  In the water-based adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin, in order to improve the adhesiveness as described above, curing such as a polyvalent aldehyde, a water-soluble epoxy resin, a melamine-based compound, a zirconia-based compound, and a zinc compound Compounds can be formulated. As an example of the water-soluble epoxy resin, it is possible to use an aqueous solution obtained by reacting epichlorohydrin with a polyamide polyamine obtained by the reaction of a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine and a dicarboxylic acid such as adipic acid. Polyamide epoxy resin. As a commercial product of such polyamide epoxy resin, "Sumirez Resin 650" and "Sumirez Resin 675" sold by Sumika Chemtex Co., Ltd., "WS-525" sold by Japan PMC Co., Ltd., etc. There is. When mix | blending a water-soluble epoxy resin, the addition amount is about 1-100 mass parts normally with respect to 100 mass parts of polyvinyl alcohol-type resin, Preferably it is 1-50 mass parts.

  When a urethane resin is used as the main component of the water-based adhesive, it is effective to use a polyester ionomer urethane resin as the main component of the water-based adhesive. The polyester-based ionomer-type urethane resin as referred to herein is a urethane resin having a polyester skeleton, into which a small amount of ionic component (hydrophilic component) is introduced. Such an ionomer-type urethane resin can be used as a water-based adhesive because it is directly emulsified in water without using an emulsifier to form an emulsion. When using a polyester-based ionomer-type urethane resin, it is effective to blend a water-soluble epoxy compound as a crosslinking agent. The polyester-based ionomer-type urethane resin as an adhesive for the polarizing plate is described, for example, in JP-A-2005-70140 and JP-A-2005-208456.

  Each of these components constituting the water-based adhesive is usually used in the state of being dissolved in water. The water-based adhesive is applied onto a suitable substrate and dried to obtain an adhesive layer. Components that do not dissolve in water may be in the state of being dispersed in the system.

  As a method of forming the said adhesive bond layer on this retardation film, the method of apply | coating said adhesive composition directly on this retardation film surface, and forming an adhesive bond layer etc. are mentioned. The thickness of the adhesive layer is usually about 0.001 to 5 μm, preferably 0.01 μm or more, preferably 4 μm or less, and more preferably 3 μm or less. When the adhesive layer is too thick, the appearance of the polarizing plate tends to be poor.

  Also, for example, after the obtained water-based adhesive is injected between the polarizing plate and the retardation film, the water is evaporated by heating and the thermal crosslinking reaction is advanced to give sufficient adhesiveness to both. Can.

  The active energy ray-curable adhesive may be cured as it receives irradiation with active energy rays and can bond the polarizing plate and the retardation film with a strength sufficient for practical use. For example, a cationically polymerizable active energy ray-curable adhesive containing an epoxy compound and a cationic polymerization initiator, a radically polymerizable active energy ray-curable adhesive containing an acrylic curing component and a radical polymerization initiator, an epoxy compound An active energy ray-curable adhesive comprising both a cationically polymerizable curing component such as: and a radically polymerizable curing component such as an acrylic compound, and having incorporated therein a cationic polymerization initiator and a radical polymerization initiator And an electron beam curable adhesive which is cured by irradiating an active energy ray curable adhesive containing no initiator with an electron beam. Preferably, it is a radically polymerizable active energy ray-curable adhesive containing an acrylic curing component and a radical polymerization initiator. Further, a cationically polymerizable active energy ray-curable adhesive containing an epoxy compound and a cationic polymerization initiator which can be used substantially without a solvent is preferable.

  A cationically polymerizable epoxy compound that is liquid at room temperature, has adequate fluidity without the presence of a solvent, and provides suitable cured adhesive strength, and a cationic compound suitable therefor The active energy ray-curable adhesive compounded with the polymerization initiator can omit the drying equipment usually required in the process of bonding the polarizer and the transparent protective film in the manufacturing equipment of the polarizing plate. In addition, irradiation with an appropriate dose of active energy can accelerate the curing rate and improve the production rate.

  The epoxy compound used for such an adhesive is, for example, a glycidyl ether compound of an aromatic compound or a chain compound having a hydroxyl group, a glycidyl amination product of a compound having an amino group, a chain compound having a C—C double bond Or a cycloaliphatic epoxy compound in which a glycidyloxy group or an epoxyethyl group is bonded directly or via an alkylene to a saturated carbon ring, or an epoxy group is directly bonded to a saturated carbon ring it can. These epoxy compounds may be used alone or in combination of two or more different ones. Among them, alicyclic epoxy compounds are preferably used because they are excellent in cationic polymerization.

  The glycidyl etherification thing of the aromatic compound which has a hydroxyl group, or a chain compound can be manufactured by the method of carrying out addition condensation of the epichlorohydrin to the hydroxyl group of these aromatic compounds or a chain compound under basic conditions, for example. Such glycidyl ethers of hydroxyl-containing aromatic compounds or chain compounds include diglycidyl ethers of bisphenols, polyaromatic ring epoxy resins, diglycidyl ethers of alkylene glycols or polyalkylene glycols, and the like. .

  As diglycidyl ethers of bisphenols, for example, glycidyl ether of bisphenol A and its oligomer, glycidyl ether of bisphenol F and its oligomer, 3,3 ', 5,5'-tetramethyl-4,4'- Examples thereof include glycidyl ether of biphenol and its oligomer.

  As polyaromatic ring epoxy resin, for example, glycidyl ether of phenol novolak resin, glycidyl ether of cresol novolak resin, glycidyl ether of phenol aralkyl resin, glycidyl ether of naphthol aralkyl resin, glycidyl ether of phenol dicyclopentadiene resin And the like. Further, glycidyl ethers of trisphenols and their oligomers and the like also belong to polyaromatic ring epoxy resins.

  Examples of diglycidyl ethers of alkylene glycols or polyalkylene glycols include glycidyl ether of ethylene glycol, glycidyl ether of diethylene glycol, glycidyl ether of 1,4-butanediol, glycidyl ether of 1,6-hexanediol, etc. It can be mentioned.

  The glycidyl amination thing of the compound which has an amino group can be manufactured, for example by the method of carrying out addition condensation of the epichlorohydrin to the amino group of the said compound under basic conditions. The compound having an amino group may simultaneously have a hydroxyl group. Such glycidyl amino compounds of compounds having an amino group include glycidyl amino compounds of 1,3-phenylene diamine and oligomers thereof, glycidyl amino compounds of 1,4-phenylene diamine and oligomers thereof, 3-aminophenol Glycidyl amination and glycidyl esterification product of glycidyl aglycinate and its oligomer, glycidyl amination and glycidyl esterification product of 4-aminophenol and its oligomer, and the like are included.

  Epoxides of linear compounds having C—C double bonds can be prepared by epoxidation of the C—C double bonds of the linear compounds with a peroxide under basic conditions. Chain compounds having a C—C double bond include butadiene, polybutadiene, isoprene, pentadiene, hexadiene and the like. In addition, terpenes having a double bond can also be used as an epoxidation raw material, and as non-cyclic monoterpenes, there are linalool and the like. The peroxide used for epoxidation can be, for example, hydrogen peroxide, peracetic acid, tert-butyl hydroperoxide and the like.

  An alicyclic epoxy compound in which a glycidyl oxy group or an epoxyethyl group is bonded to a saturated carbon ring directly or through an alkylene is an aromatic ring of a hydroxyl group-containing aromatic compound represented by bisphenols listed above. The glycidyl ether compound of the hydrogenated polyhydroxy compound obtained by hydrogenation, the glycidyl ether compound of the cycloalkane compound which has a hydroxyl group, the epoxy compound of the cycloalkane compound which has a vinyl group, etc. can be used.

  The epoxy compounds described above are readily commercially available, and for example, the “jER” series sold by Mitsubishi Chemical Corporation under the trade names and “Epiclon” sold by DIC Corporation. "Epototh (registered trademark)" sold by Toto Kasei Co., Ltd., "Adecaresin (registered trademark)" sold by ADEKA Co., Ltd., "Denacol (registered trademark) sold by Nagase ChemteX Co., Ltd." ], “Dow Epoxy” sold by Dow Chemical Co., Ltd., “TEPIC (registered trademark)” sold by Nissan Chemical Industries, Ltd., and the like.

  On the other hand, an alicyclic epoxy compound in which an epoxy group is directly bonded to a saturated carbon ring is, for example, basic to a C-C double bond of a non-aromatic cyclic compound having a C-C double bond in the ring It can be produced by the method of epoxidation using peroxide under the conditions. As a non-aromatic cyclic compound having a C—C double bond in the ring, for example, a compound having a cyclopentene ring, a compound having a cyclohexene ring, at least two carbon atoms bonded to a cyclopentene ring or a cyclohexene ring Polycyclic compounds forming an additional ring and the like can be mentioned. A non-aromatic cyclic compound having a C—C double bond in the ring may have another C—C double bond outside the ring. Examples of non-aromatic cyclic compounds having a C—C double bond in the ring include cyclohexene, 4-vinylcyclohexene, single ring monoterpenes limonene and α-pinene.

  In an alicyclic epoxy compound in which an epoxy group is directly bonded to a saturated carbocyclic ring, an alicyclic structure having an epoxy group directly bonded to a ring as described above is intramolecularly via a suitable linking group It may be a compound formed at least two. The linking group as referred to herein includes, for example, an ester bond, an ether bond, an alkylene bond and the like.

Specific examples of the alicyclic epoxy compound in which the epoxy group is directly bonded to a saturated carbon ring are as follows.
3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate,
1,2-epoxy-4-vinylcyclohexane,
1,2-epoxy-4-epoxyethylcyclohexane,
1,2-epoxy-1-methyl-4- (1-methylepoxyethyl) cyclohexane, 3,4-epoxycyclohexylmethyl (meth) acrylate,
An adduct of 2,2-bis (hydroxymethyl) -1-butanol with 4-epoxyethyl-1,2-epoxycyclohexane,
Ethylene bis (3,4-epoxycyclohexane carboxylate),
Oxydiethylene bis (3,4-epoxycyclohexanecarboxylate),
1,4-cyclohexanedimethyl bis (3,4-epoxycyclohexanecarboxylate),
3- (3,4-epoxycyclohexylmethoxycarbonyl) propyl 3,4-epoxycyclohexane carboxylate and the like.

  Commercially available products can also be easily obtained from the alicyclic epoxy compounds in which an epoxy group is directly bonded to the saturated carbon ring described above, and for example, they are sold by Daicel Corporation under the respective trade names. These include the “Ceroxide” series and “Cyclomer”, and the “Syracure UVR” series sold by Dow Chemical.

  The curable adhesive containing an epoxy compound may further contain an active energy ray-curable compound other than the epoxy compound. Examples of the active energy ray curable compound other than the epoxy compound include, for example, an oxetane compound and an acrylic compound. Among them, it is preferable to use an oxetane compound in combination since there is a possibility of accelerating the curing rate in cationic polymerization.

The oxetane compound is a compound having a four-membered ring ether in the molecule, and examples thereof include the following.
1,4-bis [(3-ethyloxetan-3-yl) methoxymethyl] benzene,
3-ethyl-3- (2-ethylhexyl oxymethyl) oxetane,
Bis (3-ethyl-3-oxetanylmethyl) ether,
3-ethyl-3- (phenoxymethyl) oxetane,
3-ethyl-3- (cyclohexyloxymethyl) oxetane,
Phenolic novolac oxetane,
1,3-bis [(3-ethyl oxetan-3-yl) methoxy] benzene and the like.

  Commercially available oxetane compounds are also easily obtainable, and for example, “Aron Oxetane (registered trademark)” series sold by Toagosei Co., Ltd. under the respective trade names, and sold by Ube Industries, Ltd. And the “ETERNACOLL (registered trademark)” series.

  As a curable compound including an epoxy compound and an oxetane compound, it is preferable to use one which has not been diluted with an organic solvent or the like in order to make the adhesive compounded with such a compound no solvent. In addition, other components that constitute the adhesive, and small amounts of components including cationic polymerization initiators and sensitizers described later are also removed and dried from the organic solvent than those dissolved in the organic solvent. It is preferred to use a powder or liquid of the compound alone.

  The cationic polymerization initiator is a compound which is irradiated with active energy rays such as ultraviolet rays to generate cationic species. It may be any one that gives the adhesive strength and curing speed required for the compounded adhesive, but, for example, aromatic diazonium salts; onium salts such as aromatic iodonium salts and aromatic sulfonium salts; iron-arene complexes Etc. These cationic polymerization initiators may be used alone or in combination of two or more different ones.

Examples of the aromatic diazonium salt include the following.
Benzenediazonium hexafluoroantimonate,
Benzenediazonium hexafluorophosphate,
Benzene diazonium hexafluoroborate etc.

Examples of the aromatic iodonium salt include the following.
Diphenyliodonium tetrakis (pentafluorophenyl) borate,
Diphenyliodonium hexafluorophosphate,
Diphenyliodonium hexafluoroantimonate,
Bis (4-nonylphenyl) iodonium hexafluorophosphate and the like.

Examples of the aromatic sulfonium salt include the following.
Triphenylsulfonium hexafluorophosphate,
Triphenylsulfonium hexafluoroantimonate,
Triphenylsulfonium tetrakis (pentafluorophenyl) borate,
Diphenyl (4-phenylthiophenyl) sulfonium hexafluoroantimonate,
4,4'-bis (diphenylsulfonio) diphenyl sulfide bishexafluorophosphate,
4,4'-bis [di (β-hydroxyethoxyphenyl) sulfonio] diphenyl sulfide bishexafluoroantimonate,
4,4'-bis [di (β-hydroxyethoxyphenyl) sulfonio] diphenyl sulfide bishexafluorophosphate,
7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate,
7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate
4-phenylcarbonyl-4'-diphenylsulfoniodiphenyl sulfide hexafluorophosphate,
4- (p-tert-butylphenylcarbonyl) -4′-diphenylsulfonio diphenyl sulfide hexafluoroantimonate,
4- (p-tert-butylphenylcarbonyl) -4′-di (p-toluyl) sulfonio-diphenyl sulfide tetrakis (pentafluorophenyl) borate and the like.

Examples of the iron-arene complex include the following.
Xylene-cyclopentadienyliron (II) hexafluoroantimonate,
Cumene-cyclopentadienyliron (II) hexafluorophosphate,
Xylene-cyclopentadienyliron (II) tris (trifluoromethylsulfonyl) methanide and the like.

  Among the cationic polymerization initiators, the aromatic sulfonium salt has an ultraviolet absorbing property even in a wavelength range of 300 nm or more, so it is excellent in curability and can give an adhesive layer having good mechanical strength and adhesive strength. Therefore, it is preferably used.

  Commercially available cationic polymerization initiators are also readily available. For example, “Kayarad (registered trademark)” series sold by Nippon Kayaku Co., Ltd. under the respective trade names, and sold by Dow Chemical Co. "Cyracure UVI" series, photo acid generator "CPI" series sold by San-Apro Ltd., photo acid generator "TAZ", "BBI" and "DTS" sold by Midori Chemical Co., Ltd. And the "Adeka Optomer" series sold by ADEKA Co., Ltd., and "RHODORSIL (registered trademark)" sold by Rhodia.

  In the active energy ray-curable adhesive, the cationic polymerization initiator is usually blended in a ratio of 0.5 to 20 parts by mass, preferably 1 to 15 with respect to 100 parts by mass of the total amount of the active energy ray-curable adhesive. It is a mass part. If the amount is too small, curing may be insufficient and the mechanical strength and adhesive strength of the adhesive layer may be reduced. When the amount is too large, the hygroscopicity of the adhesive layer may be increased by the increase of the ionic substance in the adhesive layer, and the durability performance of the obtained polarizing plate may be lowered.

  When the active energy ray-curable adhesive is used in the electron beam curing type, it is not particularly necessary to include a photopolymerization initiator in the composition, but in the case of using the ultraviolet curing type, a photo radical generator is used Is preferred. Examples of the photo radical generator include a hydrogen abstraction type photo radical generator and a cleavage type photo radical generator.

  Examples of hydrogen abstraction type photoradical generators include 1-methylnaphthalene, 2-methylnaphthalene, 1-fluoronaphthalene, 1-chloronaphthalene, 2-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene, 1-iodonaphthalene Naphthalene derivatives such as 2-iodonaphthalene, 1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene, 1,4-dicyanonaphthalene, anthracene, 1,2-benzanthracene, 9,10-dichloroanthracene Anthracene derivatives such as 9,10-dibromoanthracene, 9,10-diphenylanthracene, 9-cyanoanthracene, 9,10-dicyanoanthracene, 2,6,9,10-tetracyanoanthracene, pyrene derivatives, carbazole 9-methylcarbazole, 9-phenylcarbazole, 9-prop-2-ynyl-9H-carbazole, 9-propyl-9H-carbazole, 9-vinylcarbazole, 9H-carbazole-9-ethanol, 9-methyl-3-nitro -9H-carbazole, 9-methyl-3,6-dinitro-9H-carbazole, 9-octanoylcarbazole, 9-carbazolemethanol, 9-carbazolepropionic acid, 9-carbazolepropionitrile, 9-ethyl-3,6 -Dinitro-9H-carbazole, 9-ethyl-3-nitrocarbazole, 9-ethylcarbazole, 9-isopropylcarbazole, 9- (ethoxycarbonylmethyl) carbazole, 9- (morpholinomethyl) carbazole, 9-acetylcarbazole, 9- Allyl Rubazole, 9-benzyl-9H-carbazole, 9-carbazoleacetic acid, 9- (2-nitrophenyl) carbazole, 9- (4-methoxyphenyl) carbazole, 9- (1-ethoxy-2-methyl-propyl) -9H -Carbazole, 3-nitrocarbazole, 4-hydroxycarbazole, 3,6-dinitro-9H-carbazole, 3,6-diphenyl-9H-carbazole, 2-hydroxycarbazole, 3,6-diacetyl-9-ethylcarbazole and the like Carbazole derivative, benzophenone, 4-phenylbenzophenone, 4,4'-bis (dimethoxy) benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, methyl 2-benzoylbenzoate Ester, 2- Benzophenone derivatives such as methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, aromatic carbonyl compounds, [4- (4-methyl) Phenylthio) phenyl] -phenylmethanone, xanthone, thioxanthone, 2-chlorothioxanthone, 4-chlorothioxanthone, 2-isopropyl thioxanthone, 4-isopropyl thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, 1- Thioxanthone derivatives such as chloro-4-propoxythioxanthone and coumarin derivatives can be mentioned.

  The cleavage type photoradical generator is a type of photoradical generator in which the compound is cleaved to generate a radical upon irradiation with active energy rays, and specific examples thereof include arylalkyls such as benzoin ether derivatives and acetophenone derivatives. Ketones, oxime ketones, acyl phosphine oxides, S-phenyl thiobenzoate, titanocenes, and derivatives obtained by polymerizing them may be mentioned, but it is not limited thereto. Commercially available cleavage type photoradical generators include 1- (4-dodecylbenzoyl) -1-hydroxy-1-methylethane, 1- (4-isopropylbenzoyl) -1-hydroxy-1-methylethane, 1-benzoyl -1-hydroxy-1-methyl ethane, 1- [4- (2-hydroxyethoxy) -benzoyl] -1-hydroxy-1-methyl ethane, 1- [4- (acryloyloxyethoxy) -benzoyl] -1-hydroxy- 1-Methylethane, diphenyl ketone, phenyl-1-hydroxy-cyclohexyl ketone, benzyl dimethyl ketal, bis (cyclopentadienyl) -bis (2,6-difluoro-3-pyryl-phenyl) titanium, (η6-isopropylbenzene) -(Η 5-cyclopentadienyl) -iron (II) hexaf Fluorophosphate, trimethylbenzoyl diphenyl phosphine oxide, bis (2,6-dimethoxy-benzoyl)-(2,4,4-trimethyl-pentyl) -phosphine oxide, bis (2,4,6-trimethyl benzoyl) -2, 4-Dipentoxyphenyl phosphine oxide or bis (2,4,6-trimethylbenzoyl) phenyl-phosphine oxide, (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane, 4- (methylthiobenzoyl) -1 -Methyl 1-morpholino ethane etc. is mentioned, but it is not limited to this.

  Among the active energy curing adhesives used in the present invention, any of the photoradical generators contained in the electron beam curing type, that is, hydrogen abstraction type or cleavage type photoradical generators can be used alone respectively. A plurality of other combinations may be used, but a combination of one or more cleavage-type photoradical generators is more preferable in terms of the stability of the single radical photogenerator and the curability. Among the cleavage type photoradical generators, acyl phosphine oxides are preferable, and more specifically, trimethyl benzoyl diphenyl phosphine oxide (trade name “DAROCURE TPO”; Ciba Japan Ltd.), bis (2,6-dimethoxy-) Benzoyl)-(2,4,4-trimethyl-pentyl) -phosphine oxide (trade name “CGI 403”; Ciba Japan Ltd.), or bis (2,4,6-trimethyl benzoyl) -2,4- Dipentoxyphenyl phosphine oxide (trade name “Irgacure 819”; Ciba Japan Ltd.) is preferable.

  The active energy ray-curable adhesive can contain a sensitizer as required. By using a sensitizer, the reactivity can be improved, and the mechanical strength and the adhesive strength of the adhesive layer can be further improved. As the sensitizer, those described above can be appropriately applied.

  When mix | blending a sensitizer, it is preferable to make the compounding quantity into the range of 0.1-20 mass parts with respect to 100 mass parts of total amounts of an active energy ray hardening-type adhesive agent.

  Various additives can be blended into the active energy ray-curable adhesive as long as the effect is not impaired. As an additive which can be blended, an ion trap agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow control agent, a plasticizer, an antifoamer etc. are mentioned, for example.

  Each of these components which comprise an active energy ray hardening-type adhesive agent is usually used in the state melt | dissolved in the solvent. When the active energy ray-curable adhesive contains a solvent, the active energy ray-curable adhesive is coated on a suitable substrate and dried to obtain an adhesive layer. The components that do not dissolve in the solvent may be in the state of being dispersed in the system.

As a method of forming the said adhesive bond layer on this retardation film, the method of apply | coating said adhesive composition directly on this retardation film surface, and forming an adhesive bond layer etc. are mentioned. The thickness of the adhesive layer is usually about 0.001 to 5 μm, preferably 0.01 μm or more, preferably 2 μm or less, and more preferably 1 μm or less. When the adhesive layer is too thick, the appearance of the polarizing plate tends to be poor.

  The active energy ray-curable adhesive can be applied to the film by the application method described above. Under the present circumstances, as a viscosity of an active energy ray hardening-type adhesive agent, what is necessary is just to have the viscosity which can be coated by various methods, The viscosity in the temperature 25 degreeC is in the range of 10-30,000 mPa * sec. Is preferably, and more preferably in the range of 50 to 6,000 mPa · sec. If the viscosity is too small, it will tend to be difficult to obtain a uniform coating without unevenness. On the other hand, when the viscosity is too large, it tends to be difficult to flow, and it is also difficult to obtain a uniform coating film without unevenness. The viscosity referred to herein is a value measured at 60 rpm after temperature control of the adhesive at 25 ° C. using a B-type viscometer.

  The active energy ray-curable adhesive can be used in an electron beam-curable or ultraviolet-curable mode. The active energy ray of the present invention is defined as an energy ray capable of decomposing a compound generating an active species to generate an active species. Examples of such active energy rays include visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, γ-rays and electron beams.

  In the electron beam curing type, as the irradiation condition of the electron beam, any appropriate condition can be adopted as long as the above-mentioned active energy ray curing type adhesive can be cured. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive and curing may be insufficient. If the acceleration voltage exceeds 300 kV, the penetration through the sample is too strong and the electron beam bounces, resulting in a transparent protective film or There is a risk of damaging the polarizer. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. If the irradiation dose is less than 5 kGy, the adhesive will be undercured, and if it exceeds 100 kGy, the transparent protective film or the polarizer will be damaged, causing a decrease in mechanical strength or yellowing to obtain the desired optical properties. I can not

  Electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the air or under a condition where a small amount of oxygen is introduced. Depending on the material of the transparent protective film, by appropriately introducing oxygen, it is possible to cause oxygen inhibition to occur on the transparent protective film surface that the electron beam first strikes, to prevent damage to the transparent protective film, and only to the adhesive Electron beams can be irradiated efficiently.

In the ultraviolet ray curing type, the light irradiation intensity of the active energy ray curable adhesive is determined depending on the composition of the adhesive and is not particularly limited, but it is preferably 10 to 5000 mW / cm ² . When the light irradiation intensity to the resin composition is less than 10 mW / cm ² , the reaction time becomes too long, and when it exceeds 5000 mW / cm ² , adhesion is caused by heat radiated from the light source and heat generation during polymerization of the composition. It may cause yellowing of the component materials of the agent and deterioration of the polarizer.
The irradiation intensity is preferably an intensity in a wavelength range effective for activating the cationic photopolymerization initiator, more preferably an intensity in a wavelength range of 400 nm or less, and still more preferably a wavelength range of 280 to 320 nm Strength at Such once with light intensity or by irradiation a plurality of times, the integrated light quantity 10 mJ / cm ² or more, preferably be set to be 10~5,000mJ / cm ^2. When the accumulated light amount to the adhesive is less than 10 mJ / cm ² , generation of the active species derived from the polymerization initiator is not sufficient, and curing of the adhesive becomes insufficient. On the other hand, when the integrated light amount exceeds 5,000 mJ / cm ² , the irradiation time becomes very long, which is disadvantageous to the improvement of productivity. At this time, depending on the film used and the combination of adhesive types, it depends on which wavelength region (UVA (320 to 390 nm), UVB (280 to 320 nm), etc.) the integrated light amount is required.

  The light source used to carry out polymerization curing of the adhesive by irradiation of active energy rays in the present invention is not particularly limited, and, for example, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, super high pressure mercury lamp, xenon lamp, halogen lamp, carbon An arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting a wavelength range of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, and a metal halide lamp can be mentioned. From the viewpoint of energy stability and simplicity of the apparatus, an ultraviolet light source having a light emission distribution at a wavelength of 400 nm or less is preferable.

[Circularly polarizing plate]
The present retardation film can be combined with a polarizing plate to obtain a circularly polarizing plate (hereinafter sometimes referred to as a true circularly polarizing plate) including the present retardation film and a polarizing plate. The present retardation film and the polarizing plate are usually pasted together with an adhesive.
With respect to the slow axis (optical axis) of the first retardation layer of the present optical film, it is preferable to set so as to be substantially 15 ° with the transmission axis or the absorption axis of the polarizing plate. Substantially 15 ° is usually in the range of 15 ° ± 5 °. Further, the angle between the absorption axis or transmission axis of the polarizing plate and the optical axis of the second retardation layer is, with respect to the angle θ between the transmission axis or absorption axis of the polarizing plate and the optical axis of the first retardation layer, The angle is preferably set to satisfy 2θ + 45 °. More preferably, it is set to be 60 ° substantially when θ = 15 °. The substantially 60 ° is usually in the range of 60 ° ± 5 °. On the other hand, as described in JP-A-2004-126538, the optical axis angles of the first retardation layer and the second retardation layer are 30 ° and -30 with respect to the transmission axis or absorption axis of the polarizing plate. It is known that the function as a wide band λ / 4 plate can be exhibited even at ° or 45 ° and -45 °, so that it is possible to stack the layers by a desired method.

  The polarizing plate used in the present circularly polarizing plate may have a protective film on one side of the polarizer, or may have a protective film on both sides of the polarizer. The protective film in this case may use a substrate on which the first and second retardation layers of the present invention are formed. In addition, the polymerizable liquid crystal composition may be directly coated on the polarizing plate to form a retardation layer, or the polarizing layer may be bonded to the polarizer surface using an adhesive. An adhesive may be used to bond the retardation layer.

As a method of bonding this retardation film which does not have a base material to other substrates, such as a polarizer side or a polarizing plate, a method of bonding this retardation film to other bases using an adhesive agent And the method etc. of removing the base material which formed retardation film, after bonding this retardation film to other base materials using an adhesive agent are mentioned. At this time, the adhesive may be applied to the retardation layer side of the retardation film of the present invention, or may be applied to the other substrate side. When there is an alignment film between the substrate and the retardation layer, the alignment film may be removed together with the substrate.

A substrate having on its surface a functional group that forms a chemical bond with the retardation layer or the alignment film tends to form a chemical bond with the retardation layer or the alignment film and the like, and tends to be difficult to remove. Therefore, when peeling and removing a base material, the base material with few functional groups of the surface is preferable, and the base material which has not given the surface treatment which forms a functional group on the surface is preferred.
In addition, since the alignment film having a functional group that forms a chemical bond with the substrate tends to increase the adhesion between the substrate and the alignment film, when the substrate is peeled off and removed, the substrate is chemically bonded to the substrate It is preferable that the alignment film has few functional groups to form. In addition, it is preferable that a reagent for crosslinking the substrate and the alignment film is not contained, and further, a component such as a solvent which dissolves the substrate in a solution such as an alignment polymer composition and a composition for forming a photoalignment film Is preferably not included.
Furthermore, in the alignment film having a functional group that forms a chemical bond with the retardation layer, the adhesion between the retardation layer and the alignment film tends to be large. Therefore, when removing an alignment film with a base material, the alignment film with few functional groups which form a chemical bond with a phase difference layer is preferable. Further, it is preferable that the retardation layer and the alignment film do not contain a reagent for crosslinking the retardation layer and the alignment film.
In addition, in the retardation layer having a functional group that forms a chemical bond with the alignment film, the adhesion between the alignment film and the retardation layer tends to be large. Therefore, when removing a base material, or when removing an alignment film with a base material, the phase difference layer with few functional groups which form a chemical bond with a base material or alignment film is preferable. In addition, the polymerizable liquid crystal composition preferably does not contain a reagent for crosslinking the substrate or the alignment film with the retardation layer.

<Polarizer>
The polarizing plate may be a film having a polarizing function. As the said film, the stretched film to which the pigment | dye which has absorption anisotropy was made to adsorb | suck, the film etc. which contain the film which apply | coated the pigment | dye which has absorption anisotropy as a polarizer are mentioned. Examples of dyes having absorption anisotropy include dichroic dyes.

  A film containing, as a polarizer, a stretched film to which a dye having absorption anisotropy is adsorbed is usually a step of uniaxially stretching a polyvinyl alcohol-based resin film, or by dyeing the polyvinyl alcohol-based resin film with a dichroic dye At least at least a polarizer produced through a step of adsorbing a dichroic dye, a step of treating a polyvinyl alcohol-based resin film to which the dichroic dye is adsorbed with an aqueous solution of boric acid, and a step of washing with an aqueous solution of boric acid It is produced by sandwiching a transparent protective film on one side via an adhesive.

  The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate resin, besides polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

  The degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal modified with aldehydes and polyvinyl acetal can also be used. The polymerization degree of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, and preferably in the range of 1,500 to 5,000.

  What formed such a polyvinyl alcohol-type resin into a film is used as a raw film film of a polarizing plate. The method of forming the polyvinyl alcohol-based resin into a film is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film can be, for example, about 10 to 150 μm.

  Uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after the dyeing with the dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the boric acid treatment. Moreover, it is also possible to uniaxially stretch in these several steps. In uniaxial stretching, uniaxial stretching may be performed between rolls having different peripheral speeds, or uniaxial stretching may be performed using a heat roll. In addition, uniaxial stretching may be dry stretching in which stretching is performed in the air, or may be wet stretching in which a polyvinyl alcohol resin film is swollen using a solvent. The stretching ratio is usually about 3 to 8 times.

  Dyeing of a polyvinyl alcohol-based resin film with a dichroic dye is performed, for example, by a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye. Specifically, iodine or a dichroic organic dye is used as the dichroic dye. Examples of the dichroic organic dye include a dichroic direct dye consisting of a disazo compound such as CI DIRECT RED 39 and a dichroic direct dye consisting of a compound such as trisazo or tetrakisazo. The polyvinyl alcohol-based resin film is preferably subjected to immersion treatment in water before the dyeing treatment.

  When using iodine as a dichroic dye, the method of immersing and dye | staining a polyvinyl-alcohol-type resin film the aqueous solution containing an iodine and potassium iodide is employ | adopted normally. The content of iodine in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water. The content of potassium iodide is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ° C. Moreover, the immersion time (staining time) to this aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when using a dichroism organic dye as a dichroism pigment, the method of immersing and dye | staining a polyvinyl alcohol-type resin film the aqueous solution containing water-soluble dichroism dye is employ | adopted normally.
The content of the dichroic organic dye in this aqueous solution is usually about 1 × 10 ^-4 to 10 parts by mass, preferably 1 × 10 ^-3 to 1 part by mass, and more preferably 100 parts by mass of water. It is 1 × 10 ⁻³ to 1 × 10 ⁻² parts by mass. The aqueous solution may contain an inorganic salt such as sodium sulfate as a staining aid. The temperature of the aqueous dichroic dye solution used for dyeing is usually about 20 to 80 ° C. Moreover, the immersion time (staining time) to this aqueous solution is usually about 10 to 1,800 seconds.

  The boric acid process after dyeing | staining with a dichroic dye can be normally performed by the method of immersing the dyed polyvinyl alcohol-type resin film in boric-acid aqueous solution. The content of boric acid in the aqueous boric acid solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the dichroic dye, the aqueous boric acid solution preferably contains potassium iodide, and the content of potassium iodide in that case is usually 0.1 to 100 parts by mass of water. It is about 15 parts by mass, preferably 5 to 12 parts by mass. The immersion time in the boric acid aqueous solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of boric acid treatment is usually 50 ° C. or higher, preferably 50 to 85 ° C., and more preferably 60 to 80 ° C.

The polyvinyl alcohol resin film after boric acid treatment is usually washed with water. The water washing process can be performed by the method of immersing the boric-acid-treated polyvinyl alcohol-type resin film in water, for example. The temperature of water in the water washing treatment is usually about 5 to 40 ° C.
The immersion time is usually about 1 to 120 seconds.

  After washing with water, drying treatment is performed to obtain a polarizer. The drying process can be performed, for example, using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100 ° C, preferably 50 to 80 ° C. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. By the drying process, the moisture content of the polarizer is reduced to a practical level. The water content is usually about 5 to 20% by weight, preferably 8 to 15% by weight. When the moisture content is less than 5% by weight, the flexibility of the polarizer is lost, and the polarizer may be damaged or broken after it is dried. If the water content exceeds 20% by weight, the thermal stability of the polarizer may be deteriorated.

  Thus, the thickness of a polarizer obtained by uniaxially stretching, dyeing with a dichroic dye, boric acid treatment, washing with water and drying on a polyvinyl alcohol-based resin film is preferably 5 to 40 μm.

Examples of the film coated with a dye having absorption anisotropy include a composition obtained by applying a composition containing a dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a polymerizable liquid crystal. It can be mentioned. The film preferably has a protective film on one side or both sides.
As the said protective film, the same thing as the above-mentioned base material is mentioned.

  It is preferable that the film coated with the dye having absorption anisotropy is thin, but if it is too thin, the strength tends to be reduced and the processability tends to be poor. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

  As a film which apply | coated the pigment | dye which has the said absorption anisotropy, the film as described in Unexamined-Japanese-Patent No. 2012-33249 etc. is mentioned specifically ,.

  A polarizing plate is obtained by laminating a transparent protective film on at least one surface of the thus obtained polarizer via an adhesive. As a transparent protective film, the same transparent film as the base material mentioned above can be used preferably, and the retardation film of the present invention can also be used.

(Optical characteristics of polarizing plate)
The polarization performance of the polarizing plate can be represented mainly by numerical values called single transmittance and polarization degree, which are respectively defined by the following formulas.
Single transmittance (λ) = 0.5 × (Tp (λ) + Tc (λ))
Degree of polarization (λ) = 100 × (Tp (λ) −Tc (λ)) / (Tp (λ) + Tc (λ))

  Here, Tp (λ) is the transmittance (%) of a polarizing plate or a polarizing film measured in a relationship of linear polarization of incident wavelength λ nm and parallel Nicol, and Tc (λ) is a straight line of incident wavelength λ nm It is the transmittance | permeability (%) of the polarizing plate or polarizing film measured by the relationship of polarization | polarized-light and cross nicol, and it is a measured value obtained by both the polarization ultraviolet visible absorption spectrum measurement by a spectrophotometer. In addition, the single transmittance (λ) and the degree of polarization (λ) obtained for each wavelength, subjected to sensitivity correction called visibility correction, are respectively the visibility correction single transmittance (Ty) and the visibility correction polarization. It is called degree (Py). The values of Ty and Py can be simply measured, for example, with an absorptiometer (model number: V7100) manufactured by JASCO Corporation.

  The polarizing plate according to the present invention preferably has a visible light correction single transmittance (Ty) of 42% or more, and preferably a visible light correction polarization degree (Py) of 99.9% or more. The visibility correction single transmittance is preferably 43% or more, more preferably 44% or more. The visibility correction polarization degree (Py) is preferably 99.9% or more, but may be 99.0% or more, and further 99.5% or more.

  The transmission hue a of the polarizing plate is preferably -3.0 to 1.5, more preferably -2.5 to 1.0, and still more preferably -2.0 to 0.5. is there. b is preferably −1.5 or more and 6.0 or less, more preferably −1.0 or more and 5.5 or less, and still more preferably −0.5 or more and 5.0 or less.

  The above-mentioned transmission hue means the hue of light transmitted from one surface of the polarizing plate when light is applied from the other surface. The hue here can be represented by an a value and a b value in the Lab color system, and is measured using standard light. In the present invention, the measurement of the transmission hue of the polarizing film is carried out in a state where an adhesive layer is provided on one side of the polarizing film and the adhesive layer is bonded to the glass plate. The Lab color system is represented by the lightness index L of the hunter and the hues a and b as described in "5.5 Accelerated weathering test" of JIS K 5981: 2006 "Synthetic resin powder coating". It is a thing. As a concept similar to the Lab color system, there is an L * a * b * color system specified in JIS Z 8781-4: 2013 “Colorimetry-Part 4: CIE 1976 L * a * b * space”. However, in the present invention, the Lab color system is adopted. The lightness index L and the values of the hues a and b are calculated from the tristimulus values X, Y and Z defined in JIS Z 8722: 2009 "Method of measuring color-reflection and transmission object color" according to the following equation .

L = 10 Y ^1/2
a = 17.5 (10.2 X-Y) / Y ^1/2
b = 7.0 (Y-0.847Z) / Y1 / ² .

  In the Lab color system, the hue a and b values can indicate the position corresponding to the saturation, the hue changes to red when the hue a increases, and changes to yellow when the hue b increases. Each changes. The closer to 0, the closer to achromatic color.

The structure of the retardation film of the present invention will be described in detail with reference to FIG. The retardation film 100 is formed of a first retardation layer 1 and a second retardation layer 2 as shown in FIG. The first retardation layer 1 and / or the second retardation layer 2 may be formed on the substrate 3 and have a protective layer 7 between the first retardation layer 1 and the second retardation layer. You may From the viewpoint of reducing the thickness, the first phase layer 1 and the second phase difference layer 2 are continuously coated and formed on the substrate as shown in FIGS. 1-2, 1-3, 1-4, and 1. -5, the retardation film of FIGS. 1-6 is preferable. In addition, the first retardation layer 1 and / or the second retardation layer 2 may have an alignment film between the base material or the respective layers.
As a further preferred embodiment, the retardation film 100 of FIGS. 1-7, 1-8, and 1-9 combined with the third retardation layer 8 can be used.

  The circularly polarizing plate 110 of the present invention will be described in detail with reference to FIG. The circularly polarizing plate 110 of the present invention includes the retardation film 100 of the present invention, and is obtained by forming the polarizing plate 6, the first retardation layer 1 and the second retardation layer 2 in this order. Fig. 2-5, Fig. 2-6 in which a retardation film and a polarizing plate integrally formed by continuously coating the first phase layer 1 and the second phase difference layer 2 on a base material are integrated by an adhesive. The circularly polarizing plate of FIG. 2-7 is preferable from the viewpoint of thinning. Further, the same is applied to FIGS. 2-8 and 2-9 in which the first retardation layer 1 and / or the second retardation layer 2 are peeled and transferred from the base material and integrated with the polarizing plate with a pressure sensitive adhesive. It is preferable from the viewpoint of thinning.

The present retardation film and the present circularly polarizing plate can be used in various display devices.
The display device is a device having a display element, and includes a light emitting element or a light emitting device as a light emitting source. As a display device, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (for example, field emission display device (FED), surface field emission display device (SED)), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (for example, grating light valve (GLV) display device, display device having digital micro mirror device (DMD)) And liquid crystal display devices such as transmissive liquid crystal display devices, transflective liquid crystal display devices, reflective liquid crystal display devices, direct-view liquid crystal display devices, projection liquid crystal display devices, etc. These display devices display a table that displays a two-dimensional image. It may be a device or a three-dimensional display device for displaying a three-dimensional image, and in particular, the circularly polarizing plate is effectively used for an organic electroluminescence (EL) display device and an inorganic electroluminescence (EL) display device. The present optical compensation polarizing plate can be effectively used in liquid crystal display devices and touch panel display devices.

  FIG. 3 is a schematic view showing the organic EL display device 30. As shown in FIG. The organic EL display device 30 shown in FIG. 3A includes the circularly polarizing plate 31, and the light emitting layer 35, and the light emitting layer 35 on the substrate 32 on which the pixel electrode 34 is formed via the interlayer insulating film 33. The cathode electrode 36 is laminated. The circularly polarizing plate 31 is disposed on the opposite side of the substrate 32 from the light emitting layer 35. The light emitting layer 35 emits light by applying a positive voltage to the pixel electrode 34 and a negative voltage to the cathode electrode 36 and applying a direct current between the pixel electrode 34 and the cathode electrode 36. The light emitting layer 35 includes an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the light emitting layer 35 passes through the pixel electrode 34, the interlayer insulating film 33, the substrate 32, and the circularly polarizing plate 31.

  In order to manufacture the organic EL display device 30, first, the thin film transistor 38 is formed on the substrate 32 in a desired shape. Then, the interlayer insulating film 33 is formed, and then the pixel electrode 34 is formed by sputtering and patterned. Thereafter, the light emitting layer 35 is stacked.

  Next, the circularly polarizing plate 31 is provided on the surface of the substrate 32 opposite to the surface on which the thin film transistor 38 is provided. In that case, the polarizing plate in the circularly polarizing plate 31 is disposed so as to be the outer side (the opposite side of the substrate 32).

  Examples of the substrate 32 include sapphire glass substrates, quartz glass substrates, soda glass substrates, ceramic substrates such as alumina; metal substrates such as copper; plastic substrates and the like. Although not shown, a thermally conductive film may be formed on the substrate 32. The heat conductive film may, for example, be a diamond thin film (DLC or the like). When the pixel electrode 34 is of a reflective type, light is emitted in the direction opposite to that of the substrate 32. Therefore, not only transparent materials but also non-transparent materials such as stainless steel can be used. The substrate may be formed singly or may be formed as a laminated substrate by bonding a plurality of substrates with an adhesive. In addition, these substrates are not limited to plate-like ones, and may be films.

  As the thin film transistor 38, for example, a polycrystalline silicon transistor may be used. The thin film transistor 38 is provided at the end of the pixel electrode 34, and the size thereof is about 10 to 30 μm. The size of the pixel electrode 34 is about 20 μm × 20 μm to 300 μm × 300 μm.

  The wiring electrode of the thin film transistor 38 is provided on the substrate 32. The wiring electrode has a low resistance and is electrically connected to the pixel electrode 34 to reduce the resistance value. Generally, the wiring electrode is made of Al, Al and a transition metal (except for Ti), Ti or A titanium nitride (TiN) containing one or more kinds is used.

An interlayer insulating film 33 is provided between the thin film transistor 38 and the pixel electrode 34. The interlayer insulating film 33 is formed by sputtering or vacuum deposition of an inorganic material such as silicon oxide such as SiO ₂ or silicon nitride, a silicon oxide layer formed by SOG (spin on glass), photoresist, polyimide And any coating such as a resin-based material such as an acrylic resin, as long as it has insulation.

  Ribs 39 are formed on the interlayer insulating film 33. The rib 39 is disposed at the periphery (between adjacent pixels) of the pixel electrode 34. Examples of the material of the ribs 39 include acrylic resin and polyimide resin. The thickness of the rib 39 is preferably 1.0 μm to 3.5 μm, and more preferably 1.5 μm to 2.5 μm.

  Next, an EL element including the pixel electrode 34, the light emitting layer 35, and the cathode electrode 36 will be described. The light emitting layer 35 has at least one hole transport layer and at least one light emitting layer, and has, for example, an electron injection transport layer, a light emitting layer, a hole transport layer, and a hole injection layer sequentially.

Examples of the pixel electrode 34 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO ₂ and In ₂ O _{3 and the} like, with ITO and IZO being particularly preferable. The thickness of the pixel electrode 35 may be a thickness of a certain level or more that can sufficiently inject holes, and is preferably about 10 to 500 nm.

  The pixel electrode 34 can be formed by a vapor deposition method (preferably, a sputtering method). The sputtering gas is not particularly limited, and inert gases such as Ar, He, Ne, Kr and Xe, or mixed gases thereof may be used.

  As a constituent material of the cathode electrode 36, for example, metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn and Zr may be used. In order to improve the operation stability of the electrode, it is preferable to use a binary or ternary alloy system selected from the exemplified metal elements. As an alloy system, for example, Ag · Mg (Ag: 1 to 20 at%), Al·Li (Li: 0.3 to 14 at%), In · Mg (Mg: 50 to 80 at%), and Al · Ca (Ca: 5 to 20 at%) and the like are preferable.

  The cathode electrode 36 is formed by vapor deposition, sputtering or the like. The thickness of the cathode electrode 37 is preferably 0.1 nm or more, preferably 1 to 500 nm or more.

  The hole injection layer has a function of facilitating the injection of holes from the pixel electrode 34, and the hole transport layer has a function of transporting holes and a function of blocking electrons, and a charge injection layer or charge It is also called a transport layer.

  The thickness of the light emitting layer, the combined thickness of the hole injecting layer and the hole transporting layer, and the thickness of the electron injecting and transporting layer are not particularly limited and may vary depending on the forming method, but should be about 5 to 100 nm. Is preferred. Various organic compounds can be used for the hole injection layer and the hole transport layer. The formation of the hole injecting and transporting layer, the light emitting layer, and the electron injecting and transporting layer can be performed by vacuum evaporation in that a homogeneous thin film can be formed.

  As the light emitting layer 35, one using light emission (fluorescence) from singlet excitons, one using light emission (phosphorescence) from triplet excitons, light emission (fluorescence) from singlet excitons Those including those using and those utilizing light emission (phosphorescence) from triplet excitons, those formed by organic matter, those including those formed by organic matter and those formed by inorganic matter, high Materials of molecules, low molecular materials, materials containing high molecular materials and low molecular materials, and the like can be used. However, the present invention is not limited to this, and the light emitting layer 35 using various known materials for EL elements can be used for the organic EL display device 30.

  A desiccant (not shown) is disposed in the space between the cathode electrode 36 and the sealing layer 37. This is because the light emitting layer 35 is weak to humidity. Moisture is absorbed by the desiccant to prevent deterioration of the light emitting layer 35.

  The organic EL display device 30 of the present invention shown in FIG. 3B includes the circularly polarizing plate 31, and the light emitting layer is formed on the substrate 32 on which the pixel electrode 34 is formed via the interlayer insulating film 33. 35 and a cathode electrode 36 are laminated. A sealing layer 37 is formed on the cathode electrode, and the circularly polarizing plate 31 is disposed on the opposite side of the substrate 32. The light emitted from the light emitting layer 35 passes through the cathode electrode 36, the sealing layer 37, and the circularly polarizing plate 31.

  Hereinafter, the present invention will be described in more detail by way of examples. Unless otherwise indicated, "%" and "parts" in the examples are% by mass and parts by mass.

Nippon Zeon Co., Ltd. ZF-14 was used for the cycloolefin polymer film (COP).
As a laser microscope, LEXT manufactured by Olympus Corporation was used.
The phase difference value was measured using KOBRA-WR manufactured by Oji Scientific Instruments. In addition, the phase difference value of 450 nm and 550 nm was calculated | required by actual value, and the phase difference value of 650 nm was calculated | required from the Cauchy's dispersion formula obtained from the measurement result of other wavelengths.

  The measurement of the reflectance Y value and the reflection hues a * and b * was measured using CM2600 d manufactured by Konica Minolta. The measurement light source was determined as D65, and the light receiving optical system was determined by SCI (including regular reflection light).

Example 1
[Manufacture of polarizing plate]
After immersing a polyvinyl alcohol film having an average degree of polymerization of about 2,400 and a degree of saponification of not less than 99.9 mol% and a thickness of 75 μm in pure water at 30 ° C, the weight ratio of iodine / potassium iodide / water is 0. It was immersed in an aqueous solution of 02/2/100 at 30 ° C. to perform iodine staining (iodine staining step). The polyvinyl alcohol film subjected to the iodine dyeing process was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 12/5/100 at 56.5 ° C. to perform boric acid treatment (boric acid treatment process) ). The polyvinyl alcohol film subjected to the boric acid treatment step was washed with pure water at 8 ° C. and then dried at 65 ° C. to obtain a polarizer (27 μm thickness after stretching) in which iodine is adsorbed and oriented to polyvinyl alcohol . At this time, stretching was performed in the iodine dyeing step and the boric acid treatment step. The total draw ratio in this drawing was 5.3. The obtained polarizer and a saponified triacetyl cellulose film (KC4 MinTAR KC4UYTAC 40 μm) were pasted together with a water-based adhesive using a nip roll. The obtained bonded product was dried at 60 ° C. for 2 minutes while maintaining the tension of 430 N / m to obtain a polarizing plate (1) having a triacetyl cellulose film as a protective film on one side. The water-based adhesive is 100 parts of water, 3 parts of carboxyl group-modified polyvinyl alcohol (Kuraray's KURARAY POVAL KL318), and a water-soluble polyamide epoxy resin (Sumika Chemtex, SMILEASE RESIN 650, aqueous solution with a solid concentration of 30%) It was prepared by adding 1.5 parts.

  The optical characteristics of the obtained polarizing plate were measured. The measurement was performed with a spectrophotometer (V7100, manufactured by JASCO Corporation) with the polarizer surface of the polarizing plate obtained above as the incident surface. The obtained visual sensitivity correction single transmittance was 42.1%, the visual sensitivity correction polarization degree was 99.996%, the single hue a was −1.1, and the single hue b was 3.7.

溶剤（９８部）：シクロペンタノン[Production of UV-curable adhesive composition]
The following components were mixed to prepare a UV curable adhesive composition.
3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate 40 parts
60 parts of diglycidyl ether of bisphenol A
Diphenyl (4-phenylthiophenyl) sulfonium
Hexafluoroantimonate (photocationic polymerization initiator) 4 parts [Preparation of composition for forming a photo alignment film]
The following components were mixed, and the obtained mixture was stirred at 80 ° C. for 1 hour to obtain a composition (1) for forming a photo alignment film.
Photo-alignable material (2 parts):

Solvent (98 parts): cyclopentanone

[Preparation of Oriented Polymer Composition (1)]
An orientation polymer composition was obtained by adding 99 parts by weight of 2-butoxyethanol to 1 part by weight of Sun Ever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is a commercially available alignment polymer.
For SE-610, the solid content was converted from the concentration described in the delivery specification.

[Preparation of Composition (A-1)]
The following components were mixed, and the obtained mixture was stirred at 80 ° C. for 1 hour to obtain a composition (A-1).

The polymerizable liquid crystal A1 and the polymerizable liquid crystal A2 were synthesized by the method described in JP-A-2010-31223.
Polymerizable liquid crystal A1 (80 parts):

Polymerizable liquid crystal A2 (20 parts):

Polymerization initiator (6 parts):
2-Dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (IRGACURE 369; manufactured by Ciba Specialty Chemicals)
Leveling agent (0.1 part): polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
Solvent: Cyclopentanone (400 parts)

[Preparation of Composition (B-1)]
The composition of composition (B-1) is shown in Table A. After mixing each component and stirring the obtained solution at 80 degreeC for 1 hour, it cooled to room temperature and obtained composition (B-1).

表Ａにおける括弧内の値は、調製した組成物の全量に対する各成分の含有割合を表す。
表ＡにおけるＬＲ９０００は、ＢＡＳＦジャパン社製のＬａｒｏｍｅｒ（登録商標）ＬＲ−９０００を、Ｉｒｇ９０７は、ＢＡＳＦジャパン社製のイルガキュア（登録商標）９０７を、ＢＹＫ−３６１Ｎは、ビックケミージャパン製のレベリング剤を、ＬＣ２４２は、下記式で示されるＢＡＳＦ社製の重合性液晶を、ＰＧＭＥＡは、プロピレングリコール１−モノメチルエーテル２−アセタートを表す。

[Table A]

The values in parentheses in Table A represent the content ratio of each component to the total amount of the prepared composition.
LR9000 in Table A is Laromer (registered trademark) LR-9000 manufactured by BASF Japan, Irg 907 is Irgacure (registered trademark) 907 manufactured by BASF Japan, and BYK-361N is a leveling agent manufactured by BIC Chemie Japan And LC242 represents a polymerizable liquid crystal manufactured by BASF, represented by the following formula, and PGMEA represents propylene glycol 1-monomethyl ether 2-acetate.

[Production of First Retardation Layer (1-1)]
A roll of cycloolefin polymer film (COP) (ZF-14, manufactured by Nippon Zeon Co., Ltd. 23 μm) 500 mm wide × 100 m at a speed of 4 m / min while using a plasma processing apparatus once at an output of 0.4 kW It was processed. The composition for photo alignment film formation (1) is applied at a rate of 11.7 ml / min in the range of 460 mm using a die coater on the surface subjected to plasma treatment, dried at 100 ° C. for 2 minutes, and polarized UV irradiation Using the apparatus, polarized UV exposure was performed at an integrated light amount of 100 mJ / cm ² (integrated light amount at a wavelength of 313 nm in an air atmosphere) in the direction of 15 ° with respect to the transport direction. It was 100 nm when the film thickness of the obtained alignment film was measured with a laser microscope (LEXT, manufactured by Olympus Corporation). Subsequently, the composition (A-1) is applied onto the alignment film at a rate of 39.2 ml / min using a die coater and dried at 120 ° C. for 2 minutes, and then ultraviolet light is applied using a high pressure mercury lamp. Irradiation (in a nitrogen atmosphere, integrated light quantity at a wavelength of 365 nm: 1000 mJ / cm ² ) was carried out to obtain a film on which the first retardation layer (1-1) was formed.
It was 4.2 micrometers when the thickness of the obtained 1st phase difference layer (1-1) was confirmed with the laser microscope. Moreover, when the retardation value of the film in which the obtained 1st phase difference layer (1-1) was formed was measured, it was Re (550) = 284 nm and Rth (550) = 142 nm. Moreover, when the retardation value of wavelength 450nm and wavelength 650nm was measured, it was Re (450) = 247 nm and Re (650) = 290 nm. The relationship of the in-plane retardation value at each wavelength is as follows.
Re (450) / Re (550) = 0.87
Re (650) / Re (550) = 1.02
That is, the first retardation layer (1-1) had optical characteristics represented by the following formulas (1), (3) and (4). In addition, since the phase difference value in wavelength 450 nm, wavelength 550 nm, and wavelength 650 nm of COP is substantially zero, it does not affect the relationship of the said in-plane phase difference value.
200 nm <Re (550) <320 nm (1)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)

[Production of Second Retardation Layer (2-1)]
The composition (A-1) was applied at a rate of 19.6 ml / min using a die coater on the alignment film in the direction of 75 ° with respect to the transport direction and to the polarized UV irradiation on the photo alignment film. A film in which the second retardation layer (2-1) was formed was obtained in the same manner as in the production example of the first retardation layer (1-1) except for the first retardation layer (1-1).
It was 2.1 micrometers when the thickness of the obtained 2nd phase difference layer (2-1) was confirmed with the laser microscope. Moreover, when the retardation value of the film in which the 2nd retardation layer (2-1) was formed was measured, it was Re (550) = 142 nm and Rth (550) = 71 nm. Moreover, when the retardation value of wavelength 450nm and wavelength 650nm was measured, it was Re (450) = 124 nm and Re (650) = 145 nm. The relationship of the in-plane retardation value at each wavelength is as follows.
Re (450) / Re (550) = 0.87
Re (650) / Re (550) = 1.02
That is, the second retardation layer (2-1) had optical characteristics represented by the following formulas (2), (3) and (4). In addition, since the phase difference value in wavelength 450 nm, wavelength 550 nm, and wavelength 650 nm of COP is substantially zero, it does not affect the relationship of the said in-plane phase difference value.
100 nm <Re (550) <160 nm (2)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)

The retardation layer surface of the film having the first retardation layer formed in this manner and the COP surface of the film having the second retardation layer formed thereon are treated with an adhesive (Lintec's pressure-sensitive adhesive 5 μm). Roll-to-roll bonding was carried out to prepare a retardation film (1). The total thickness of the retardation film (1) was 57 μm. When the retardation value of the obtained retardation film (1) was measured, it was Re (550) = 143 nm. Moreover, when the retardation value of wavelength 450nm and wavelength 650nm was measured, it was Re (450) = 109 nm and Re (650) = 157 nm. The relationship of the in-plane retardation value at each wavelength is as follows.
Re (450) / Re (550) = 0.76
Re (650) / Re (550) = 1.09
That is, retardation film (1) had the optical characteristic represented by following formula (2), (3) and (4). In addition, since the phase difference value in wavelength 450 nm, wavelength 550 nm, and wavelength 650 nm of COP is substantially zero, it does not affect the relationship of the said in-plane phase difference value.
100 nm <Re (550) <160 nm (2)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)

When the single-piece transmission hue was measured using a spectrophotometer (V7100, manufactured by Nippon Bunko) for the retardation film (1), the hue a * was −1.0, and the hue b * was 2.7.
That is, retardation film (1) showed the optical characteristic represented by following formula (6), (7).
−2.0 ≦ a * ≦ 0.5 (6)
−0.5 ≦ b * ≦ 5.0 (7)

  The measurement results of the optical properties of the first retardation layer, the second retardation layer, and the retardation film (1) are shown in Table 1.

Furthermore, the COP surface on the first retardation layer side of the retardation film (1) is subjected to a corona treatment, a UV curable adhesive composition is coated thereon by a microgravure coater, and the polarization of the polarizing plate is thereon It piled up with the child side, and it integrated by passing between two bonding rolls. Under the present circumstances, since it becomes Roll to Roll bonding, the angle which the absorption axis of this polarizing plate and the slow axis of a 1st phase difference layer (1-1) to make becomes 15 degrees. Moreover, the rubber roll whose surface is rubber is used for the 1st bonding roll among two bonding rolls, and the metal by which the chromium plating was given to the surface is used for the 2nd bonding roll. I used a roll. After the integration, using an ultraviolet irradiation device using a metal halide lamp as a light source, the ultraviolet ray is irradiated from the polarizing plate side so that the integrated light amount at a wavelength of 320 to 400 nm becomes 200 mJ / cm ² The adhesive layer was cured, and the retardation film (1) and the polarizer (1) were adhered to obtain a circularly polarizing plate (1) having a total thickness of 125 μm. The ellipticity measurement results of this circularly polarizing plate (1) are shown in Table 2. The surface on the second retardation layer side of the circularly polarizing plate (1) was bonded to a mirror using an adhesive, and the hue change was observed from all directions in the azimuth angle at the elevation angle of 60 ° from the front vertical direction. The colors when viewed from two points in the direction in which the hue change was particularly large are shown in Table 2. The circularly polarizing plate (1) had no color even when observed from any direction, and a good black display was obtained. Moreover, about the circularly-polarizing plate bonded to this mirror, the measurement of reflectance Y value and reflective hue a *, b * was performed using CM2600d by Konica Minolta. The obtained reflectance Y value was 5.3%, the reflected hue a * was 0.2, and the reflected hue b * was −0.2.

  Table 2 shows the thickness of the circularly polarizing plate (1), the elliptic polarization ratio, the measurement results of the reflection characteristics, and the observation results.

Example 2
Roll-to-roll bonding is performed on the surface on the first retardation layer side of the film in which the first retardation layer (1-1) is formed on the polarizing plate via the adhesive, and then the first retardation layer is formed. While peeling off the COP film of the film formed (1-1), the surface on the second retardation layer side of the film formed the second retardation layer (2-1) is roll-to-roll bonded, and The first retardation layer (1-1) and the second retardation layer (2-1) are formed on the polarizing plate by winding up while peeling off the COP film of the film having the two retardation layers (2-1) formed thereon. ) Was formed to obtain an extremely thin circularly polarizing plate (2) of 83 μm. Therefore, to the circularly polarizing plate (2), a retardation film comprising a first retardation layer (1-1) of 5 μm or less and a second retardation layer (2-1) of 5 μm or less is attached to the polarizing plate. It is united. The ellipticity measurement results of this circularly polarizing plate (2) are shown in Table 2. The surface on the second retardation layer side of the circularly polarizing plate (2) was bonded to a mirror using an adhesive, and the hue change from all azimuth directions at a position at an elevation angle of 60 ° from the front vertical direction was observed. The colors when viewed from two points in the direction in which the hue change was particularly large are shown in Table 2. The circularly polarizing plate (2) had no color even when observed from any direction, and a good black display was obtained.

Example 3
A film having a first retardation layer (1-1) formed is prepared in the same manner as in Example 1, and the first retardation layer surface is subjected to a corona treatment, and the UV curable adhesive composition is formed thereon. A microgravure coater was applied, and ultraviolet irradiation was performed using an ultraviolet irradiation apparatus using a metal halide lamp as a light source so that the integrated light quantity at a wavelength of 320 to 400 nm was 200 mJ / cm ² to form an intermediate layer with a thickness of 1 μm. Furthermore, the intermediate layer was subjected to plasma treatment to form a second retardation layer (2-1) in the same manner as in Example 1 to produce a retardation film (2). Subsequently, in the same manner as in Example 1, the polarizing plate and the surface on the second retardation layer side of the retardation film (2) were bonded to obtain a circularly polarizing plate (3). The ellipticity measurement results of this circularly polarizing plate (3) are shown in Table 2. The COP-side surface of the circularly polarizing plate (3) was bonded to a mirror using an adhesive, and the hue change from all azimuth directions at an elevation angle of 60 ° from the front vertical direction was observed. The colors when viewed from two points in the direction in which the hue change was particularly large are shown in Table 2. The circularly polarizing plate (3) had no color even when observed from any direction, and a good black display was obtained.

Example 4
A film in which the first retardation layer (1-1) is formed in the same manner as in Example 1 is produced, and the film in which the first retardation layer is formed is carried out on the side opposite to the first retardation layer. A second retardation layer (2-1) was formed in the same manner as in Example 1 to prepare a retardation film (3). Subsequently, a polarizing plate and a retardation film (3) are combined in the same manner as in Example 1 except that the first retardation layer surface is adhesively bonded to the polarizing plate through an adhesive, and a circularly polarizing plate (4) I got The ellipticity measurement results of this circularly polarizing plate (4) are shown in Table 2.
The surface on the second retardation layer side of the circularly polarizing plate (4) was bonded to a mirror using an adhesive, and the hue change from all azimuth directions at a position at an elevation angle of 60 ° from the front vertical direction was observed. The colors when viewed from two points in the direction in which the hue change was particularly large are shown in Table 2. The circularly polarizing plate (4) had no color even when observed from any direction, and a good black display was obtained.

Example 5
[Production of Third Retardation Layer]
A roll of cycloolefin polymer film (COP) (ZF-14, manufactured by Nippon Zeon Co., Ltd. 23 μm) 500 mm wide × 100 m at a speed of 4 m / min while using a plasma processing apparatus once at an output of 0.4 kW It was processed. The oriented polymer composition was coated on the plasma-treated surface at a rate of 11.7 ml / min using a die coater within a width of 460 mm and dried at 90 ° C. for 1 minute to obtain an oriented film. . It was 50 nm when the film thickness of the obtained alignment film was measured with the laser microscope. Subsequently, the composition (B-1) is applied onto the alignment film at a rate of 6.2 ml / min using a die coater and dried at 90 ° C. for 1 minute, and then ultraviolet light is applied using a high pressure mercury lamp. Irradiation (in a nitrogen atmosphere, integrated light quantity at a wavelength of 365 nm: 1000 mJ / cm ² ) was carried out to obtain a film on which a third retardation layer was formed. When the film thickness of the obtained 3rd phase difference layer was measured with the laser microscope, the film thickness was 550 nm. Moreover, when the retardation value in wavelength 550 nm of the film in which the obtained 3rd phase difference layer was formed was measured, it was Re (550) = 1 nm and Rth (550) = -75 nm.
That is, the third retardation layer had optical properties represented by the following formula (5). In addition, since the phase difference value in wavelength 550 nm of COP is about 0, it does not affect the said optical characteristic.
nx ny ny <nz (5)

The COP surface of the film on which the third retardation layer was formed was the surface on the second retardation layer side of the retardation film (1) of Example 1 and an adhesive (Lintec's pressure-sensitive adhesive 5 μm) Through Roll to Roll, to produce a retardation film (4). The total thickness of the retardation film (4) was 86 μm. It was Re (550) = 144 nm when the retardation value of the obtained retardation film (4) was measured. Moreover, when the retardation value of wavelength 450nm and wavelength 650nm was measured, it was Re (450) = 110 nm and Re (650) = 157 nm. The relationship of the in-plane retardation value at each wavelength is as follows.
Re (450) / Re (550) = 0.76
Re (650) / Re (550) = 1.09
That is, the retardation film (4) had optical characteristics represented by the following formulas (2), (3), (4) and (6). In addition, since the phase difference value in wavelength 450 nm, wavelength 550 nm, and wavelength 650 nm of COP is substantially zero, it does not affect the relationship of the said in-plane phase difference value.
100 nm <Re (550) <160 nm (2)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
nx>nz> ny (6)

  A circularly polarizing plate (5) was obtained by bonding the COP surface on the first retardation layer side of the obtained retardation film (4) to a polarizing plate in the same manner as in Example 1. The ellipticity measurement results of this circularly polarizing plate (5) are shown in Table 2. The surface on the third retardation layer side of the circularly polarizing plate (5) was bonded to a mirror using an adhesive, and the hue change from all azimuth directions at a position at an elevation angle of 60 ° from the front vertical direction was observed. Table 2 shows colors when viewed from two points in the direction in which the hue change was particularly large. The circularly polarizing plate (5) had no color even when observed from any direction, and a good black display was obtained.

Example 6
Implementation except using a sheet-fed polycarbonate film (brand name "Pure Ace RM" manufactured by Teijin Limited 50 μm) instead of the roll-shaped cycloolefin polymer film (COP) (ZF-14 manufactured by Nippon Zeon Co., Ltd. 23 μm) The first retardation layer (1-1) was formed in the same manner as in the production example of the first retardation layer (1-1) of Example 1, to produce a retardation film (5). In Example 6, since there is a phase difference in the polycarbonate film, the polycarbonate film is used as a second retardation layer. Thereafter, in the same manner as in Example 1, the polarizing plate and the first retardation layer surface of the retardation film (5) were bonded via an adhesive to obtain a circularly polarizing plate (6). The ellipticity measurement results of this circularly polarizing plate (6) are shown in Table 2. The polycarbonate film surface of the circularly polarizing plate (6) was bonded to a mirror using an adhesive, and the hue change from all directions in azimuth was observed at a position at an elevation angle of 60 ° from the front vertical direction. The colors when viewed from two points in the direction in which the hue change was particularly large are shown in Table 2. The circularly polarizing plate (6) had no color even when observed from any direction, and a good black display was obtained.

Comparative Example 1
[Production of Second Retardation Layer (2-2)]
A film having a second retardation layer (2-2) was produced in the same manner as in Example 1 except that the irradiation direction of polarized UV was changed from 15 ° to 45 °.

  In the same manner as in Example 1, a film having a second retardation layer (2-2) and a polarizing plate were bonded to obtain a circularly polarizing plate (7). The ellipticity measurement results of this circularly polarizing plate (7) are shown in Table 2. The ellipticity was lower than in Examples 1 to 6, and the front reflection color was slightly purple. The surface on the second retardation layer side of the circularly polarizing plate (7) was bonded to a mirror using an adhesive, and the hue change from all azimuth directions at a position at an elevation angle of 60 ° from the front vertical direction was observed. Table 2 shows colors when viewed from two points in the direction in which the hue change was particularly large. The circularly polarizing plate (7) was observed to exhibit bluish green as well as red as the reflected color when observed from a specific direction.

Comparative example 2
A film having a third retardation layer produced in Example 5 is further produced in the same manner as in Example 5 on the surface on the second retardation layer side of the circularly polarizing plate (7) produced in the same manner as in Comparative Example 1. A circularly polarizing plate (8) was obtained by bonding.
The ellipticity measurement results of this circularly polarizing plate (8) are shown in Table 2. The ellipticity was lower than in Examples 1 to 6, and the front reflection color was slightly purple. The third retardation layer surface of the circularly polarizing plate (8) was bonded to a mirror using an adhesive, and the hue change from all azimuth directions at a position at an elevation angle of 60 ° from the front vertical direction was observed. The colors when viewed from two points in the direction in which the hue change was particularly large are shown in Table 2. The circularly polarizing plate (8) was observed to exhibit bluish green as well as red as a reflected color when observed from a specific direction.

Comparative example 3
Example 1 is the same as Example 1 except that a roll-like longitudinally uniaxially stretched cycloolefin polymer film (COP) (ZM-14, manufactured by Nippon Zeon Co., Ltd.) is used as the first retardation layer and the second retardation layer. A circularly polarizing plate (9) was obtained by bonding to the polarizing plate by the following method. The thickness of the first retardation layer was 33 μm. Moreover, when retardation value was measured, it was Re (550) = 274 nm and Rth (550) = 137 nm. Moreover, when the retardation value of wavelength 450nm and wavelength 650nm was measured, it was Re (450) = 275 nm, Re (650) = 271 nm. The relationship of the in-plane retardation value at each wavelength is as follows.
Re (450) / Re (550) = 1.00
Re (650) / Re (550) = 0.99
The thickness of the second retardation layer was 28 μm. Moreover, when retardation value was measured, it was Re (550) = 138 nm and Rth (550) = 69 nm. Moreover, when the retardation value of wavelength 450nm and wavelength 650nm was measured, it was Re (450) = 138 nm and Re (650) = 138 nm. The relationship of the in-plane retardation value at each wavelength is as follows.
Re (450) / Re (550) = 1.00
Re (650) / Re (550) = 1.00
The ellipticity measurement results of this circularly polarizing plate (9) are shown in Table 2. In particular, the ellipticity at 450 nm was lower than in Examples 1 to 6, and the front reflection color had a deep blue color. The COP surface of the circularly polarizing plate (9) was bonded to a mirror using an adhesive, and the hue change from all directions in azimuth was observed at a position at an elevation angle of 60 ° from the front vertical direction. The colors when viewed from two points in the direction in which the hue change was particularly large are shown in Table 2. The circularly polarizing plate (9) was observed to have a reflected color of purple when observed from a specific direction.

  Also from the above measurement results, the circularly polarizing plate of the example is useful because it is excellent in anti-reflection characteristics in a bright place even when observed from all directions.

  The retardation film of the present invention is useful as an optical film excellent in light leakage suppression without coloring at the time of black display.

DESCRIPTION OF SYMBOLS 1 1st phase difference layer 2 2nd phase difference layer 3 base material 100 this phase difference film 4 alignment film 5 adhesive agent 6 polarizing plate 7 protective layer 8 3rd phase difference layer 200 organic electroluminescence display 30 organic electroluminescence display 31 circularly polarizing plate 32 substrate 33 interlayer insulating film 34 pixel electrode 35 light emitting layer 36 cathode electrode 37 sealing layer 38 thin film transistor 39 rib

Claims (19)

A retardation film having at least two retardation layers and having a first retardation layer and a second retardation layer,
The first retardation layer is
It has an optical characteristic represented by Formula (1), Formula (3) and Formula (4),
The second retardation layer is
(2) and (3) and (4) have the optical properties,
The retardation film is
The retardation film which has an optical characteristic represented by Formula (2) and Formula (3) and Formula (4).
200 nm <Re (550) <320 nm (1)
100 nm <Re (550) <160 nm (2)
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
(Wherein, Re (450) represents an in-plane retardation value at a wavelength of 450 nm, Re (550) represents an in-plane retardation value at a wavelength of 550 nm, and Re (650) represents an in-plane retardation value at a wavelength of 650 nm. Represent) The retardation film according to claim 1, further comprising a third retardation layer represented by Formula (5).
nx ny ny <nz (5)
(Nx represents the main refractive index in the direction parallel to the film plane in the refractive index ellipsoid formed by the retardation layer, ny represents the refractive index ellipsoid formed by the retardation layer relative to the film plane Represents the refractive index in the direction perpendicular to the direction of nx, and nz represents the refractive index in the direction perpendicular to the film plane in the refractive index ellipsoid formed by the retardation layer. Represent) It is retardation film of Claim 1 or Claim 2, Comprising: Retardation film which has an optical characteristic represented by Formula (6) and (7).
−2.0 ≦ a * ≦ 0.5 (6)
−0.5 ≦ b * ≦ 5.0 (7)
(Wherein, a * and b * represent color coordinates in the L * a * b * color system) The retardation film according to any one of claims 1 to 3, wherein the first retardation layer is a coating layer formed by polymerizing one or more polymerizable liquid crystals. The retardation film according to any one of claims 1 to 4, wherein the second retardation layer is a coating layer formed by polymerizing one or more polymerizable liquid crystals. The thickness of a 1st phase difference layer is 5 micrometers or less, Retardation film of any one of Claims 1-5. The thickness of a 2nd phase difference layer is 5 micrometers or less, Retardation film of any one of Claims 1-6. The retardation film according to any one of claims 1 to 7, wherein the thickness of each of the first retardation layer and the second retardation layer is 5 μm or less. A first retardation layer is formed on the substrate with or without the alignment film, and a second retardation layer is formed on the first retardation layer with or without the alignment film. The retardation film according to any one of claims 1 to 8, wherein is formed. A second retardation layer is formed on the substrate with or without the alignment film, and a first retardation layer with or without the alignment film is formed on the second retardation layer. The phase difference film according to any one of claims 1 to 9, wherein is formed. A first retardation layer is formed on one side of the substrate with or without the alignment film, and a second retardation layer is formed on the other side of the substrate with or without the alignment film. The phase difference film according to any one of claims 1 to 9, wherein is formed. 10. The substrate according to any one of claims 1 to 9, wherein the substrate has the optical properties of the first retardation layer, and the second retardation layer is formed on the substrate with or without the alignment film. Retardation film as described in 1 or 2. The substrate according to any one of claims 1 to 9, wherein the substrate has the optical properties of the second retardation layer, and the first retardation layer is formed on the substrate with or without the alignment film. Retardation film as described in 1 or 2. The retardation film according to any one of claims 1 to 9, wherein an angle between the optical axes of the first retardation layer and the second retardation layer is substantially 60 °. The retardation film according to any one of claims 7 to 12, further comprising a protective layer between the first retardation layer and the second retardation layer. A circularly polarizing plate comprising the retardation film according to any one of claims 1 to 15 and a polarizing plate. The angle between the absorption axis or transmission axis of the polarizing plate and the optical axis of the second retardation layer is substantially the angle θ between the absorption axis or transmission axis of the polarizing plate and the optical axis of the first retardation layer The circularly polarizing plate according to claim 16, which has a relationship of 2θ + 45 °. An organic EL display device comprising the circularly polarizing plate according to claim 16 or 17. A touch panel display device comprising the circularly polarizing plate according to claim 16 or 17.

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