TW202326188A - Optical film and manufacturing method thereof - Google Patents

Abstract

The present invention provides a novel optical film controlled in optical refractive index in three dimensional directions for the entire visible light range and for all viewing directions, and a method for manufacturing the same. The optical film of the present invention has a first retardation layer and a second retardation layer, and satisfying the relationship of the following formulas (1) and (2). 0.4 ≤ Nz (450) ≤ 0.6 (1) 0.4 ≤ Nz (550) ≤ 0.6 (2) [In the formula, Nz (450) represents the Nz coefficient of the optical film with respect to the light of the wavelength [lambda] = 450 nm, and Nz (550) represents the Nz coefficient of the optical film for the light of the wavelength [lambda] = 550 nm.].

Description

Optical film and manufacturing method thereof

The invention relates to an optical film and its manufacturing method.

Flat panel display (FPD) uses optical films such as polarizers and retardation plates. The retardation film is required to have a uniform phase shift in the entire range of visible light. For example, Patent Document 1 discloses a reverse wavelength dispersion retardation film aligned in the horizontal direction; Patent Document 2 discloses a reverse wavelength dispersion retardation film aligned in the vertical direction membrane.

[Prior Art Literature]

[Patent Document]

[Patent Document 1] Japanese National Publication No. 2010-537955

[Patent Document 2] Japanese Unexamined Patent Publication No. 2015-57646

In recent years, with the evolution of flat panel displays, it is gradually required to obtain a clear black display from any direction. According to this situation, it is clear that only the wavelength dispersion in the horizontal or vertical direction is controlled There will be insufficient topics.

The present invention includes the following inventions.

[1] An optical film having a first retardation layer and a second retardation layer and satisfying the relationship of the following formulas (1) and (2),

0.4≦Nz(450)≦0.6 (1)

0.4≦Nz(550)≦0.6 (2) [In the formula, Nz(450) represents the Nz coefficient of the optical film to the light of wavelength λ=450nm, and Nz(550) represents the coefficient of the optical film to the light of wavelength λ=550nm Nz coefficient, the Nz coefficient Nz(λ) of the optical film to the light of wavelength λ(nm) is given by

Nz(λ)=(nx(λ)-nz(λ))/(nx(λ)-ny(λ)) means; nx(λ) means that in the refractive index ellipsoid formed by the optical film, for the wavelength λ (nm) light, the main refractive index in the direction parallel to the film plane; ny (λ) means that in the refractive index ellipsoid formed by the optical film, for the light of wavelength λ (nm), the main refractive index is parallel to the film plane and The refractive index in the direction perpendicular to the nx(λ) direction; nz(λ) means that in the refractive index ellipsoid formed by the optical film, for the light of wavelength λ(nm), between the directions perpendicular to the film plane Refractive Index].

[2] The optical film as described in [1] above, wherein the first retardation layer is:

In the range of wavelength λ=400 to 700nm in the refractive index ellipsoid formed by the first retardation layer, there is a relationship of nx1(λ)>ny1(λ)≒nz1(λ), [wherein, nx1(λ) is Indicates that in the refractive index ellipsoid formed by the first retardation layer, for the light of wavelength λ (nm), the main force in the direction parallel to the film plane Refractive index; ny1 (λ) means that in the refractive index ellipsoid formed by the first retardation layer, the light of the wavelength λ (nm) in the direction parallel to the film plane and orthogonal to the direction of the aforementioned nx1 (λ) Refractive index; nz1 (λ) means that in the refractive index ellipsoid formed by the first retardation layer, for the light of wavelength λ (nm), the refractive index in the direction perpendicular to the film plane];

And satisfy the relationship of the following formulas (3) and (4),

Re1(450)/Re1(550)≦1.00 (3)

1.00≦Re1(650)/Re1(550) (4) [In the formula, Re1(450) represents the in-plane retardation value of the first retardation layer for light of wavelength λ=450nm, and Re1(550) represents For the in-plane retardation value of the first retardation layer for the light of wavelength λ=550nm, Re1(650) means the in-plane retardation value of the first retardation layer for the light of wavelength λ=650nm, for the wavelength λnm The in-plane retardation value Re1(λ) of the first retardation layer of light is given by

Re1(λ)=(nx1(λ)-ny1(λ))×d1 represents that, here, d1 represents the thickness of the first retardation layer].

[3] The optical film as described in [1] above or [2] above, wherein the second retardation layer is:

In the range of wavelength λ=400 to 700nm in the refractive index ellipsoid formed by the second retardation layer, there is a relationship of nz2(λ)>nx2(λ)≒ny2(λ), [wherein, nz2(λ) is Represents the refractive index in the direction perpendicular to the film plane for light of wavelength λ (nm) in the refractive index ellipsoid formed by the second retardation layer; nx2(λ) represents the refraction formed in the second retardation layer In the rate ellipsoid, for light of wavelength λ (nm), the maximum refraction in the direction parallel to the film plane Refractive index; ny2(λ) means that in the refractive index ellipsoid formed by the second retardation layer, the refractive index of the light with wavelength λ(nm) in the direction parallel to the film plane and orthogonal to the aforementioned nx2 direction ; But when nx2(λ)=ny2(λ), nx2(λ) means the refractive index in any direction parallel to the film plane];

And satisfy the relationship of the following formulas (5) and (6),

Rth2(450)/Rth2(550)≦1.00 (5)

1.00≦Rth2(650)/Rth2(550) (6) [In the formula, Rth2(450) represents the retardation value in the thickness direction for the light of wavelength λ=450nm, and Rth2(550) represents the retardation value for the wavelength λ=550nm The retardation value of the thickness direction of the second retardation layer of the light of the second retardation layer, Rth2 (650) means the retardation value of the thickness direction of the second retardation layer for the light of wavelength 650nm, for the light of wavelength λ (nm) The retardation value Rth2(λ) in the thickness direction of the second retardation layer is given by

Rth2(λ)=[(nx2(λ)+ny2(λ))/2-nz2(λ)]×d2 means that, in the refractive index ellipsoid formed by the second retardation layer, nz2(λ) It represents the main refractive index in the direction perpendicular to the film plane at the wavelength λ (nm), ((nx2(λ)+ny2(λ))/2) represents the average refractive index at the film plane at the wavelength λ(nm) , d2 represents the thickness of the second retardation layer].

[4] The optical film according to any one of the above items [1] to [3], wherein the first retardation layer further satisfies the relationship of the following formula (7),

120nm≦Re1(550)≦170nm (7) [In the formula, Re1(550) represents the in-plane retardation value of the first retardation layer for the light of wavelength λ=550nm].

[5] The optical device described in any one of items [1] to [4] above film, wherein the second retardation layer further has the optical characteristics shown in formula (8),

-100nm≦Rth2(550)≦-50nm (8) [In the formula, Rth2(550) represents the retardation value in the thickness direction of the second retardation layer for the light of wavelength λ=550nm].

[6] The optical film according to any one of items [1] to [5] above, wherein the second retardation layer is a coating formed by polymerizing a polymerizable liquid crystal in an aligned state. film composed of layers.

[7] The optical film according to any one of items [1] to [6] above, wherein the first retardation layer is a coating formed by polymerizing a polymerizable liquid crystal in an aligned state. film composed of layers.

[8] The optical film according to any one of the above items [1] to [7], wherein the second retardation layer has a thickness of 5 μm or less.

[9] The optical film according to any one of the above items [1] to [8], wherein the first retardation layer has a thickness of 5 μm or less.

[10] The optical film according to any one of items [1] to [9] above, wherein the first retardation layer and the second retardation layer are polymerized mainly using the same polymerizable liquid crystal compound. The formed coating layer.

[11] An elliptically polarizing plate with an optical compensation function comprising the optical film and polarizing plate described in any one of the above items [1] to [10].

[12] The elliptically polarizing plate with optical compensation function as described in [11] above, wherein the absorption axis of the polarizing plate and the slow axis of the first retardation layer have an angle of 45±5° or 135±5° in the film plane relationship, and the absorption axis of the polarizer and the slow axis of the first retardation layer and the slow axis of the second retardation layer are in the The vertical direction is perpendicular to the membrane surface.

[13] The elliptically polarizing plate with optical compensation function as described in [11] or [12] above, which is sequentially formed with a polarizing plate, an adhesive layer, a first retardation layer, an adhesive layer, and a second phase The optical laminate of the poor layer.

[14] The elliptically polarizing plate with optical compensation function as described in [11] or [12] above, which is sequentially formed with a polarizing plate, an adhesive layer, a second retardation layer, an adhesive layer, and a first phase The optical laminate of the poor layer.

[15] An organic EL display device comprising the elliptically polarizing plate with an optical compensation function described in any one of the above [11] to [14].

[16] A method of manufacturing an elliptically polarizing plate with an optical compensation function, comprising the following steps of manufacturing an elliptically polarizing plate with an optical compensation function described in any one of [11] to [14] above,

(Step 1-A) A step of forming a first phase difference layer by polymerizing a polymerizable liquid crystal compound in a horizontally aligned state after coating the substrate on which the horizontal alignment film is formed;

(Step 1-B) a step of forming a second retardation layer by polymerizing the polymerizable liquid crystal compound in a vertically aligned state after coating the substrate on which the vertical alignment film is formed; and

(Step 2) A step of transferring the liquid crystal polymer of the first retardation layer and the liquid crystal polymer of the second retardation layer from the base material via an adhesive agent, and laminating them on the polarizing plate.

According to the present invention, there is provided a novel optical film in which the refractive index of light is controlled three-dimensionally for the entire range of visible light and all orientations of visual recognition and methods of manufacture thereof. Furthermore, it provides a liquid crystal display device and an organic EL display device capable of displaying a display clearly by using the optical film.

Hereinafter, embodiments of the present invention will be described in detail. In addition, the scope of the present invention is not limited by the embodiments described here, and various changes can be made within the scope not detracting from the gist of the present invention.

The optical film of the present invention is composed of a first retardation layer and a second retardation layer. The first retardation layer and the second retardation layer can also be formed by stretching or shrinking a polymer film, but from the viewpoint of thinning, a film composed of a coating layer is preferable, wherein the The coating layer is formed by coating a polymerizable liquid crystal (hereinafter also referred to as a polymerizable liquid crystal compound) and polymerizing it in an aligned state.

In terms of thinning and the ability to arbitrarily design the wavelength dispersion characteristics, it is preferable that the first retardation layer and the second retardation layer are composed of a composition containing a polymerizable liquid crystal compound (hereinafter also referred to as "retardation layer forming composition") ”) is coated on a transparent substrate to form a layer, and becomes a polymer in the alignment state of the polymerizable liquid crystal compound by heating and cooling. In addition, as described later, the composition for retardation layer formation can further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improving agent, and the like.

The first retardation layer is a liquid crystal formed by hardening a polymerizable liquid crystal compound in a state aligned in a horizontal direction with respect to the substrate surface The cured film is preferred; the second retardation layer is preferably a liquid crystal cured film formed by hardening a polymerizable liquid crystal compound aligned in a direction perpendicular to the surface of the substrate.

The in-plane retardation value of the first retardation layer for light with a wavelength of 550 nm, that is, Re1(550), preferably satisfies the optical characteristics shown in the following formula (7). In addition, the in-plane retardation value of the first retardation layer for light with a wavelength of 450nm is Re1(450), the in-plane retardation value for light with a wavelength of 550nm is Re1(550), and the value for light with a wavelength of 650nm is Re1(450). It is also preferable that the in-plane retardation value, ie, Re1(650), satisfy the optical characteristics shown in formulas (3) and (4). It is preferable for the first retardation layer to satisfy the optical characteristics represented by the following formula (7), the following formula (3) and the following formula (4).

120nm≦Re1(550)≦170nm...(7) (In the formula, Re1(550) represents the in-plane retardation value (in-plane retardation value) of the first retardation layer for light with a wavelength of 550nm)

Re1(450)/Re1(550)≦1.0...(3)

1.00≦Re1(650)/Re1(550)...(4) (In the formula, Re1(450) represents the in-plane retardation value of the first retardation layer for light with a wavelength of 450nm, and Re1(550) represents the value of the first retardation layer The in-plane retardation value of the first retardation layer to light with a wavelength of 550nm, Re1(650) represents the in-plane retardation value of the first retardation layer to light with a wavelength of 650nm).

When the in-plane retardation value Re1 (550) of the first retardation layer exceeds the range of formula (7), when the optical film of the present invention is combined with a polarizing plate and used as an elliptical polarizing plate with an optical compensation function described later When it is attached to a mirror, there may be a problem that the front color becomes red or blue. better in-plane phase difference The range is 130nm≦Re1(550)≦160nm. When "Re1(450)/Re1(550)" of the first retardation layer is greater than 1.0, the light leakage on the short-wavelength side of the elliptically polarizing plate including the retardation layer becomes large. Preferably, it is not less than 0.75 and not more than 0.92, more preferably not less than 0.77 and not more than 0.87, more preferably not less than 0.79 and not more than 0.85.

The in-plane retardation value of the first retardation layer can be adjusted by the thickness of the retardation layer. Because the in-plane retardation value is determined by the following formula (A), in order to obtain the desired in-plane retardation value (Re1(λ): the in-plane phase of the first retardation layer at the wavelength λ(nm) difference), just adjust the three-dimensional refractive index and film thickness d1. The thickness of the retardation layer is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the retardation layer can be measured using an interference film thickness meter, a laser microscope, or a stylus film thickness meter. Also, the three-dimensional refractive index depends on the molecular structure and alignment state of the polymerizable liquid crystal compound described later.

Re1(λ)=(nx1(λ)-ny1(λ))×d1 (A) (In the formula, in the refractive index ellipsoid formed by the first retardation layer, nx1(λ)>ny1(λ)≒ The relationship between nz1(λ), nx1(λ) represents the main refractive index in the direction parallel to the film plane for the light of wavelength λ(nm). ny1(λ) represents the light of wavelength λ(nm), in In the refractive index ellipsoid formed by the first retardation layer, the refractive index in the direction parallel to the film plane and perpendicular to the direction of nx1(λ). d1 represents the thickness of the first retardation layer. Also, the so-called " ny1(λ)≒nz1(λ)" means that ny1(λ) and nz1(λ) are substantially the same, for example, it means that the numerical difference is within 0.01).

The thickness of the second retardation layer for light of wavelength λnm The retardation value in the degree direction, that is, Rth2(λ), preferably satisfies the optical characteristics shown in the following formula (8). Moreover, it is also preferable to satisfy the optical characteristics shown by following formula (5) and formula (6). It is preferable that the second retardation layer satisfy the optical characteristics shown in the following formula (8), the following formula (5) and the following formula (6).

-100nm≦Rth2(550)≦-50nm...(8) (In the formula, Rth2(550) represents the retardation value in the thickness direction of light with a wavelength of 550nm)

Rth2(450)/Rth2(550)≦1.0...(5)

1.00≦Rth2(650)/Rth2(550)...(6) (In the formula, Rth2(450) represents the retardation value in the thickness direction of light with a wavelength of 450nm, Rth2(550) represents the same meaning as above, Rth2 (650) represents the retardation value in the thickness direction for light with a wavelength of 650nm).

When the retardation value Rth2 (550) in the thickness direction of the second retardation layer exceeds the range of formula (8), when the optical film of the present invention is combined with a polarizing plate and used as an elliptical polarizing plate with an optical compensation function described later When it is attached to the mirror, the oblique hue may turn red or blue. The preferable range of the retardation value in the thickness direction is -95nm≦Rth2(550)≦-55nm, and the more preferable range is -90nm≦Rth2(550)≦-60nm. When "Rth2(450)/Rth2(550)" of the second retardation layer is greater than 1.0, light leakage on the short wavelength side of the elliptically polarizing plate including the retardation layer becomes large. Preferably, it is not less than 0.75 and not more than 0.92, more preferably not less than 0.77 and not more than 0.87, more preferably not less than 0.79 and not more than 0.85.

The retardation value in the thickness direction of the second retardation layer can be Adjusted by the thickness of the retardation layer. Because the retardation value in the thickness direction is determined by the following formula (B), in order to obtain the desired retardation value in the thickness direction (Rth2(λ): the thickness of the second retardation layer at the wavelength λ(nm) directional phase difference), just adjust the three-dimensional refractive index and film thickness d2. The thickness of the retardation layer is preferably 0.2 μm to 5 μm, more preferably 0.5 μm to 2 μm. The thickness of the retardation layer can be measured using an interference film thickness meter, a laser microscope, or a stylus film thickness meter. Also, the three-dimensional refractive index depends on the molecular structure and alignment state of the polymerizable liquid crystal compound described later.

Rth2(λ)=[(nx2(λ)+ny2(λ))/2-nz2(λ)]×d2 (B) (wherein, in the refractive index ellipsoid formed by the second retardation layer, there is nz2 (λ)>nx2(λ)≒ny2(λ), in the formula, nz2(λ) means that in the refractive index ellipsoid formed by the second retardation layer, for the light of wavelength λ(nm), the Refractive index in the direction perpendicular to the film plane. nx2(λ) represents the maximum refractive index in the direction parallel to the film plane for light with wavelength λ (nm) in the refractive index ellipsoid formed by the second retardation layer. ny2(λ) means that in the refractive index ellipsoid formed by the second retardation layer, the refractive index of light with wavelength λ(nm) in the direction parallel to the film plane and perpendicular to the direction of the aforementioned nx2. But in When nx2(λ)=ny2(λ), nx2(λ) represents the refractive index in any direction parallel to the film plane. Here, d2 represents the thickness of the second retardation layer. Also, the so-called "nx2(λ) ≒ny2(λ)" means that nx2(λ) and ny2(λ) are substantially the same, for example, it means that the numerical difference is within 0.01).

The optical film of the present invention has a first retardation layer and a second retardation layer and satisfies the relationship of the following formulas (1) and (2).

0.40≦Nz(450)≦0.60 (1)

0.40≦Nz(550)≦0.60 (2)(In the formula, Nz(λ) is the Nz coefficient that expresses the relationship of the three-dimensional refractive index for the light of wavelength λ(nm), and by Nz(λ)=(nx(λ )-nz(λ))/(nx(λ)-ny(λ)). The nx(λ) system indicates that in the refractive index ellipsoid formed by the optical film, for the light of wavelength λ(nm), the The main refractive index in the direction parallel to the plane. ny (λ) means that in the refractive index ellipsoid formed by the optical film, for the light of wavelength λ (nm), in the direction parallel to the film plane and positive to the nx (λ) Refractive index in the direction of intersection. nz(λ) means the refractive index in the direction perpendicular to the film plane for light with wavelength λ (nm) in the refractive index ellipsoid formed by the optical film).

That is, the optical film system of the present invention has the three-dimensional refractive index relationship of nx(λ)>nz(λ)>ny(λ), and the optical film has the relationship of formula (1) and formula (2), and is mounted on the display When used, it can impart display characteristics with excellent hue. Nz(λ) is more preferably 0.45≦Nz(450)≦0.55 and 0.45≦Nz(550)≦0.55, respectively. Here, Nz(450) represents the Nz coefficient at the wavelength λ=450nm, and Nz(550) represents the Nz coefficient at the wavelength λ=550nm.

The Nz coefficient (Nz coefficient: Nz(λ)) representing the relationship between nx(λ), ny(λ) and nz(λ) at each wavelength λ(nm) of the optical film can be calculated according to the following formula.

Nz(λ)=(nx(λ)-nz(λ))/(nx(λ)-ny(λ))

Also, when calculating the Nz coefficient of the optical film, when the front retardation value of the first retardation layer and the second retardation layer and the retardation value in the thickness direction are known, it can also be calculated according to the following formula (C): figured out.

Nz(λ)=(Rth1(λ)+Rth2(λ))/(Re1(λ)+Re2(λ))+0.5 (C) (In the formula, Re1(λ) is expressed at the wavelength λ(nm) Front side of the first retardation layer Retardation value, Re2(λ) means the front retardation value of the second phase difference layer at wavelength λ(nm), Rth1(λ) means between the thickness direction of the first phase difference layer at wavelength λ(nm). The retardation value, Rth2 (λ) represents the retardation value in the thickness direction of the second retardation layer at the wavelength λ (nm).

[polymerizable liquid crystal]

The polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable functional group (especially a photopolymerizable functional group).

The photopolymerizable functional group refers to a group capable of participating in a polymerization reaction by active radicals, acids, etc. generated from a photopolymerization initiator. Photopolymerizable functional groups include: vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, oxiranyl , Oxetanyl, etc. In particular, acryloxy, methacryloxy, ethyleneoxy, oxiranyl and oxetanyl are preferred, and acryloxy is more preferred. Liquid crystallinity may be thermotropic liquid crystal or lyotropic liquid crystal, and thermotropic liquid crystal is preferable in terms of precisely controlling the film thickness. Also, the phase-ordered structure in the thermotropic liquid crystal can be a nematic liquid crystal or a smectic liquid crystal.

In the present invention, it is particularly preferable that the polymerizable liquid crystal compound has a structure of the following formula (I) in terms of exhibiting the aforementioned reverse wavelength dispersion.

In formula (I), Ar represents a divalent aromatic group which may have a substituent. The so-called aromatic group here refers to a ring structure with planarity , and the number of π electrons in the ring structure is [4n+2] according to the Huckel rule. Here n represents an integer. When containing heteroatoms such as -N=, -S- and forming a ring structure, it also includes the non-covalent bond electron pairs on these heteroatoms and satisfies Huckel's rule and has aromaticity. Among the divalent aromatic groups, it is preferable to contain at least one of nitrogen atom, oxygen atom and sulfur atom.

G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or the divalent alicyclic hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 4 carbons, a fluoroalkyl group having 1 to 4 carbons, or a fluoroalkyl group having 1 to 4 carbons. The carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted by oxygen atom, sulfur atom or nitrogen atom.

L ¹ , L ² , B ¹ and B ² each independently represent a single bond or a divalent linking group.

k and l each independently represent an integer of 0 to 3 and satisfy the relationship of 1≦k+l. Here, when 2≦k+1, B ¹ and B ² , G ¹ and G ² may be the same as or different from each other.

E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, where the hydrogen atom contained in the alkanediyl group may be replaced by a halogen atom, and the -CH ₂ - contained in the alkanediyl group may be replaced by -O-, -S-, -Si-substitution. P ¹ and P ² each independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

^G1 and ^G2 are each independently preferably 1,4-phenylenediyl that 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 carbons. 1,4-cyclohexanediyl substituted by at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbons; more preferably 1,4-cyclohexanediyl substituted by methyl phenylenediyl, unsubstituted 1,4-phenylenediyl, or unsubstituted 1,4-trans-cyclohexanediyl; particularly preferably unsubstituted 1,4-phenylenediyl, or unsubstituted 1,4-trans-cyclohexanediyl.

Also, among the plural ^G1 and ^G2 , at least one is preferably a divalent alicyclic hydrocarbon group, and among the ^G1 and ^G2 bonded to ^L1 or ^L2 , at least one One is preferably a divalent alicyclic hydrocarbon group.

L ¹ and L ² are each independently preferably a single bond, an alkylene group with 1 to 4 carbons, -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 carbons, and R ^c and R ^d represent an alkyl group having 1 to 4 carbons 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 -. Here, R ^a2-1 , R ^a4-1 , and R ^a6-1 each independently represent any of a single bond, -CH ₂ -, and -CH ₂ CH ₂ -. L ¹ and L ² are each independently a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, or -OCO-.

B ¹ and B ² are each independently preferably a single bond, an alkylene group with 1 to 4 carbons, -O-, -S-, -R ^a9 OR ^a10 -, -R ^a11 COOR ^a12 -, -R ^a13 OCOR ^a14 -, or -R ^a15 OC=OOR ^a16 -. 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 -. Here, R ^a10-1 , R ^a12-1 , and R ^a14-1 each independently represent any of a single bond, -CH ₂ -, and -CH ₂ CH ₂ -. B ¹ and B ² are each independently a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, -OCO-, or -OCOCH ₂ CH ₂ -, .

From the viewpoint of exhibiting inverse wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, more preferably k+l=4, more preferably k=2 and l=2.

E ¹ and E ² are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

Examples of polymerizable groups represented by ^P1 or ^P2 include: epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloxy group, methyl group Acryloxy group, oxirane group, and oxetanyl group, etc.

In particular, acryloxy, methacryloxy, ethyleneoxy, oxiranyl and oxetanyl are preferred, and acryloxy is more preferred.

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-attracting group. The aromatic hydrocarbon ring may, for example, be a benzene ring, a naphthalene ring, an anthracene ring, etc., preferably a benzene ring or a naphthalene ring. The aromatic heterocycle includes furan ring, benzofuran ring, pyrrole ring, indole ring, thiophene ring, benzothiophene ring, pyridine ring, pyrimidine ring, triazole ring, tricyclic ring, pyrrole ring, Pyrroline ring, imidazole ring, pyrazole ring, thiazole ring, benzothiazole ring, thienothiazole ring, azole ring, benzoxazole ring, phenanthroline ring and the like. Especially, it is preferable to have a thiazole ring, a benzothiazole ring, or a benzofuran ring, and it is more preferable to have a benzothiazolyl group. Also, when Ar contains a nitrogen atom, the nitrogen atom preferably has π electrons.

In formula (I), the total number Nπ of π electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, more preferably 14 or more, particularly preferably 16 or more. Moreover, it is preferably 30 or less, more preferably 26 or less, more preferably 24 or less.

The aromatic group represented by Ar includes, for example, the following groups.

In the formula (Ar-1) to the formula (Ar-22), the symbol * represents a linking part, and Z ⁰ , Z ¹ and Z ² are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and a cyanide group. radical, nitro, phenylsulfinyl with 1 to 12 carbons, alkylsulfonyl with 1 to 12 carbons, carboxyl, fluoroalkyl with 1 to 12 carbons, alkoxy with 1 to 6 carbons group, alkylthio group with 1 to 12 carbons, N-alkylamino group with 1 to 12 carbons, N,N-dialkylamino group with 2 to 12 carbons, N-alkane with 1 to 12 carbons sulfamoyl group or N,N-dialkylsulfamoyl group with 2 to 12 carbon atoms.

Q ¹ and Q ² each independently represent -CR ^2' R ^3' -, -S-, -NH-, -NR ^2' -, -CO- or -O-, R ^2' and R ^3' are each independently represent 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 an 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.

The aromatic hydrocarbon groups in Y ¹ , Y ² and Y ³ include phenyl, naphthyl, anthracenyl, phenanthrenyl, biphenyl and other aromatic hydrocarbon groups with 6 to 20 carbon atoms, with phenyl and naphthyl as the Best, preferably phenyl. Aromatic heterocyclic groups include furyl, pyrrolyl, thienyl, pyridyl, thiazolyl, benzothiazolyl and other heteroatoms containing at least one nitrogen atom, oxygen atom, sulfur atom, etc., with 4 to 20 carbon atoms The aromatic heterocyclic group is preferably furyl, thienyl, pyridyl, thiazolyl, and benzothiazolyl.

Y ¹ , Y ² and Y ³ can each independently be 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 a collection of aromatic rings. The polycyclic aromatic heterocyclic group refers to a condensed polycyclic aromatic heterocyclic group, or a group derived from a collection of aromatic heterocyclic rings.

Z ⁰ , Z ¹ and Z ² are each independently preferably a hydrogen atom, a halogen atom, an alkyl group with 1 to 12 carbons, a cyano group, a nitro group, or an alkoxy group with 1 to 12 carbons, and Z ⁰ is preferably A hydrogen atom, an alkyl group with 1 to 12 carbons, and a cyano group are more preferable, 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 and Q ² are preferably -NH-, -S-, -NR ^2' -, -O-, and R ^2' is preferably a hydrogen atom. Especially -S-, -O-, -NH- are especially preferable.

From the viewpoint of molecular stability, among formulas (Ar-1) to (Ar-22), formulas (Ar-6) and (Ar-7) are preferable.

In the formulas (Ar-16) to (Ar-22), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and Z ⁰ . Aromatic heterocyclic groups include those described above as aromatic heterocyclic rings that Ar may have, such as pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrimidine ring, pyrimidine ring, indole ring, quinoline ring, line ring, isoquinoline ring, purine ring, pyrrolidine (pyrrolidine) ring, etc. This aromatic heterocyclic group may have a substituent. In addition, Y ¹ may also become the aforementioned polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group which may be substituted together with the nitrogen atom to which it is bonded and Z ⁰ . Examples thereof include a benzofuran ring, a benzothiazole ring, and a benzoxazole ring.

Solid content of the composition for forming a retardation layer The total content of the polymerizable liquid crystal compound in 100 parts by mass is usually 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 80 to 94 parts by mass, more preferably 80 parts by mass Parts by mass to 90 parts by mass. When the said total content is in the said range, the orientation property of a polymeric liquid crystal compound in the retardation layer obtained will become high in the tendency for it to become high. Here, the term "solid content" refers to the total amount of components obtained by removing the solvent from the composition.

[solvent]

The solvent is preferably a solvent that can dissolve the polymerizable liquid crystal compound, and is preferably a solvent that is inert to the polymerization reaction of the polymerizable liquid crystal compound.

Solvents, for example: alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, Ester solvents such as ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and Ketone solvents such as methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane ; Chlorinated solvents such as chloroform and chlorobenzene; Dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and other amides Amine solvents, etc. These solvents may be used alone or in combination of two or more. In particular, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide-based solvents and aromatic hydrocarbon solvents are preferred.

The content of the solvent in 100 parts by weight of the composition is preferably 50 parts by weight to 98 parts by weight, more preferably 70 parts by weight to 95 parts by weight. Therefore, the solid part occupied in 100 parts by mass of the composition, It is preferably 2 to 50 parts by mass. When the solid content of the composition is 50 parts by mass or less, since the viscosity of the composition becomes low, the thickness of the retardation layer becomes approximately uniform and unevenness tends to hardly occur in the retardation layer. The above-mentioned solid content can be appropriately determined in consideration of the thickness of the retardation layer to be produced.

<polymerization initiator>

The polymerization initiator is a compound that generates a reactive species with the assistance of heat or light and can initiate polymerization reactions of polymerizable liquid crystals and the like. Reactive species include free radicals and active species such as cations or anions. In particular, a photopolymerization initiator that generates radicals when irradiated with light is preferable from the viewpoint of easy control of the reaction.

Photopolymerization initiators, such as benzoin compounds, diphenyl ketone compounds, diphenyl diketone ketal compounds, α-hydroxy ketone compounds, α-amino ketone compounds, tri-compounds, iodonium salts, and perzium salts . Specifically, Irgacure (registered trademark) 907, Irgacure184, Irgacure651, Irgacure819, Irgacure250, Irgacure369, Irgacure379, Irgacure127, Irgacure2959, Irgacure754, Irgacure379EG (above, BASF Japan Co., Ltd. manufactured); SEIKUOL BZ, SEIKUOL Z, SEIKUOL BEE (manufactured by Seiko Chemical Co., Ltd. above); kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.); kayacure UVI-6992 (manufactured by DOW Corporation); ADEKA OPTOMER SP-152, ADEKA OPTOMER SP-170, ADEKA OPTOMER N-1717 , ADEKA OPTOMER N-1919, ADEKA ARKLS NCI-831, ADEKA ARKLS NCI-930 (above, made by ADEKA Co., Ltd.); TAZ-A, TAZ-PP (above, Japan Siber Hegner Co.) and TAZ-104 (Sanwa Chemical Co., Ltd.).

In the composition for forming a retardation layer, at least one type of photopolymerization initiator is contained, preferably one or two types.

Because the energy emitted from the light source can be fully utilized and the productivity is excellent, the maximum absorption wavelength of the photopolymerization initiator is preferably 300nm to 400nm, preferably 300nm to 380nm, especially α-acetophenone It is preferably a polymerization initiator and an oxime photopolymerization initiator.

α-Acetophenone compounds include: 2-methyl-2-morpholinyl-1-(4-methylthiophenyl)propan-1-one, 2-dimethylamino-1-( 4-morpholinylphenyl)-2-benzylbutan-1-one and 2-dimethylamino-1-(4-morpholinylphenyl)-2-(4-methylphenylmethyl base) butane-1-one, etc., preferably 2-methyl-2-morpholinyl-1-(4-methylthiophenyl)propan-1-one and 2-dimethylamino-1 -(4-morpholinophenyl)-2-benzylbutan-1-one. Commercial items of the α-acetophenone compound include Irgacure 369, 379EG, and 907 (the above, manufactured by BASF Japan Co., Ltd.), SEIKUOL BEE (manufactured by Seiko Chemical Co., Ltd.), and the like.

Oxime-based photopolymerization initiators generate methyl radicals by irradiating light. The polymerization of the polymerizable liquid crystal compound in the deep part of the retardation layer proceeds favorably by the methyl radicals. Moreover, it is preferable to use the photoinitiator which can utilize the ultraviolet-ray of wavelength 350nm or more efficiently from a viewpoint of advancing the polymerization reaction in the deep part of a retardation layer more efficiently. The photopolymerization initiator that can efficiently utilize ultraviolet light with a wavelength of 350nm or more is preferably a tri-compound or an oxime ester carbazole compound. From the viewpoint of sensitivity, an oxime ester carbazole compound is preferred . Oxime ester type carbazole compounds include: 1,2-octanedione, 1-[4-(phenylthio)- 2-(O-benzoyl oxime)]ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O -Acetyl oxime) etc. Commercially available products of oxime ester type carbazole compounds include: IrgacureOXE-01, IrgacureOXE-02, IrgacureOXE-03 (above, manufactured by BASF Japan Co., Ltd.); ADEKA OPTOMER N-1919, ADEKA ARKLS NCI-831 (above, ADEKA joint stock company), etc.

The amount of the photopolymerization initiator added is generally 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, more preferably 1 to 15 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound. Within the above range, the reaction of the polymerizable group proceeds sufficiently and the alignment of the polymerizable liquid crystal compound is less likely to be disturbed.

By preparing a polymerization inhibitor, the polymerization reaction of the polymerizable liquid crystal compound can be controlled. Examples of polymerization inhibitors include: hydroquinones and hydroquinones having substituents such as alkyl ethers; catechols having substituents such as alkyl ethers such as butyl catechol; gallinols, 2,2, Free radical scavengers such as 6,6-tetramethyl-1-piperidinyloxy radical; thiophenols; β-naphthylamines and β-naphthols. In order not to disturb the alignment of the polymerizable liquid crystal compound and polymerize the polymerizable liquid crystal compound, the content of the polymerization inhibitor is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound 0.1 to 3 parts by mass.

And by using a sensitizer, a photoinitiator can be made highly sensitive. Photosensitizers, such as xanthone (xanthone), thioxanthone (thioxanthone) and other xanthones; anthracene and anthracene with substituents such as alkyl ethers; ). polymeric liquid crystal For 100 parts by mass of the compound, the content of the photosensitizer is usually 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass.

[leveling agent]

The so-called leveling agent refers to an additive that has the function of adjusting the fluidity of the composition and making the film obtained by coating the composition more flat, such as silicone-based, polyacrylate-based, and perfluoroalkane, such as silane coupling agents. Base leveling agent. Specifically, examples include: DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (the above are all manufactured by TORAY.DOW CORNING Co., Ltd.); KP321, KP323, KP324 , KP326, KP340, KP341, X22-161A, KF6001, KBM-1003, KBE-1003, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403, KBM-1403, KBM-502, KBM -503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBM-903, KBE-903, KBE-9103, KBM-573, KBM-575, KBE-585, KBM-802 , KBM-802, KBM-803, KBE-846, KBE-9007 (the above are all made by Shin-Etsu Chemical Co., Ltd.); TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all of the above are made by MOMENTIVE PERFORMANCE MATERIALS Japan contract company); fluorinert (registered trademark) FC-72, fluorinert FC-40, fluorinert FC-43, fluorinert FC-3283 (all of the above are made by Sumitomo 3M Co., Ltd. ); MEGAFACE (registered trademark) R-08, MEGAFACE R-30, MEGAFACE R-90, MEGAFACE F-410, MEGAFACE F-411, MEGAFACE F-443, MEGAFACE F-445, MEGAFACE F-470, MEGAFACE F-477, MEGAFACE F-479, MEGAFACE F-482, MEGAFACE F-483 (all of the above are DIC (stock)); EFTOP (trade name) EF301, EFTOP EF303, EFTOP EF351 , EFTOP EF352 (all of the above are manufactured by Mitsubishi Materials Corporation); SURFLON (registered trademark) S-381, SURFLON S-382, SURFLON S-383, SURFLON S-393, SURFLON SC-101, SURFLON SC -105, KH-40, SA-100 (the above are all made by AGC SEIMI CHEMICAL (stock)); trade name E1830, E5844 (made by DAIKIN FINE CHEMICAL Research Institute (stock)); BM-1000, BM-1100, BYK-352, BYK-353, and BYK-361N (all are brand names, manufactured by BM Chemie), etc.

The content of the leveling agent in the retardation layer forming composition is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound tends to be easily aligned horizontally and the retardation layer obtained becomes smoother, which is preferable. The composition for phase difference layer formation may contain 2 or more types of leveling agents.

[Substrate]

Examples of the substrate include glass substrates and film substrates, and film substrates are preferable from the viewpoint of workability, and long roll-shaped films are preferable because continuous production is possible. Resins constituting the film substrate include, for example, polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylate; fibers such as cellulose triacetate, cellulose diacetate and cellulose acetate propionate Vitamin ester; Polyethylene naphthalate; Polycarbonate; Polyethylene; Polyether; Polyether ketone;

Examples of commercially available cellulose ester substrates include "FUJITAC FILM" (manufactured by Fuji Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (above, manufactured by Konica Minolta Opto Co., Ltd.).

Commercially available cyclic olefin-based resins include "Topas" (registered trademark) (manufactured by Ticona (Germany)), "ARTON" (registered trademark) (manufactured by JSR Co., Ltd.), "ZEONOR" (registered trademark) , "ZEONEX" (registered trademark) (above, Japan ZEON Co., Ltd.) and "APEL" (registered trademark) (Mitsui Chemicals Co., Ltd.). Such a cyclic olefin-based resin can be formed into a film by known means such as a solvent casting method and a melt extrusion method, and can be used as a base material. A commercially available cyclic olefin-based resin substrate can also be used. Commercially available cyclic olefin-based resin base materials include: "S-SINA" (registered trademark), "SCA40" (registered trademark) (above, manufactured by Sekisui Chemical Co., Ltd.), "ZEONOR FILM" (registered trademark ) (OPTES Co., Ltd.) and "ARTON FILM" (registered trademark) (JSR Co., Ltd.).

In terms of practically handleable quality, the base material thickness is preferably thinner, but if it is too thin, the strength tends to decrease and the workability tends to be poor. The substrate thickness is usually 5 μm to 300 μm, preferably 20 μm to 200 μm. In addition, by releasing the base material and transferring only the polymer in the aligned state of the polymerizable liquid crystal compound, a further effect of thinning can be obtained.

[Alignment film]

The surface on the substrate to be coated with the composition for forming a retardation layer is Preferably, an alignment film is formed. The term "alignment film" refers to a substance having an alignment control ability to align the above-mentioned polymerizable liquid crystal compound in a desired direction.

The alignment film preferably has solvent resistance against dissolution due to application of the composition for forming a retardation layer, etc., and heat resistance during solvent removal and heat treatment for alignment of polymerizable liquid crystal compounds described later.

Such an alignment film facilitates the alignment of the polymerizable liquid crystal compound. In addition, various alignments such as vertical alignment, horizontal alignment, hybrid alignment, and oblique alignment can be controlled according to the type of alignment film, rubbing conditions, and light irradiation conditions.

The alignment film forming the first retardation layer is an alignment film that exhibits alignment control force in the horizontal direction. Such a horizontal alignment film includes a rubbed alignment film, a photo alignment film, and a groove alignment film having a concave-convex pattern and a plurality of grooves on the surface. When applied to a long roll film, a photo-alignment film is preferable in terms of being able to easily control the alignment direction.

Rubbed alignment films can utilize alignment polymers. Alignment polymers, for example, polyamides and gelatins with amide bonds, polyimides with amide bonds and polyamic acid, polyvinyl alcohol, and alkyl-modified polyamides Vinyl alcohol, polyacrylamide, polyazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylates. Two or more types of alignment polymers may be combined.

The rubbed alignment film is usually formed by dissolving an alignment polymer in a solvent (hereinafter also referred to as an alignment polymer composition) on a substrate and removing the solvent to form a coating film, and by applying The coating Film friction can impart alignment control force.

The concentration of the alignment polymer in the alignment polymer composition may be such that the alignment polymer is completely dissolved in the solvent. Relative to the alignment polymer composition, the content of the alignment polymer is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass.

Alignment polymer compositions are commercially available. Commercially available alignment polymer compositions include SUNEVER (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), OPTOMER (registered trademark, manufactured by JSR Corporation), and the like.

As the method of coating the alignment polymer composition on the base material, the same method as the method of coating the base material with the composition for retardation layer formation described later can be mentioned. Examples of methods for removing the solvent contained in the alignment polymer composition include natural drying, ventilation drying, heat drying, and reduced-pressure drying.

As a method of rubbing treatment, for example, a method of bringing the coating film into contact with a rotating rubbing roll wrapped with a rubbing cloth is mentioned. When performing the rubbing process, a plurality of regions (patterns) having different alignment directions can be formed on the alignment film by performing masking.

A photoalignment film is usually formed by coating a composition for forming a photoalignment film containing a polymer or monomer with a photoreactive group and a solvent on a substrate, and irradiating polarized light (preferably polarized UV) after removing the solvent. And get. The photo-alignment film can arbitrarily control the direction of the alignment control force by selecting the polarization direction of the irradiated polarized light.

The so-called photoreactive group refers to the photoreactive group produced by irradiating light. The foundation of students' orientation ability. Specifically, one of photoreactions that participate in the origin of the alignment ability, such as an alignment-induced reaction, isomerization reaction, photodimerization reaction, photocrosslinking reaction, or photodecomposition reaction of molecules generated by irradiation with light, can be mentioned. base. The photoreactive group is preferably a group with an unsaturated bond (especially a double bond); to have a group selected from a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), nitrogen - The group of at least one of the group consisting of a nitrogen double bond (N=N bond) and a carbon-oxygen double bond (C=O bond) is particularly preferred.

(formazan)基、及具有氧偶氮基苯結構之基。具有C=O鍵之光反應性基，可舉例如二苯基酮基、香豆素基、蒽醌基及順丁烯二醯亞胺基。該等基可具有烷基、烷氧基、芳基、烯丙氧基、氰基、烷氧基羰基、羥基、磺酸基、鹵化烷基等取代基。 The photoreactive group with C═C bond includes, for example, vinyl group, polyalkenyl group, stilbyl group, stilbazole group, stilbazole group, chalcone group and cinnamoyl group. The photoreactive group having a C=N bond can be, for example, a group having a structure such as an aromatic Schiff base or an aromatic hydrazone. Photoreactive groups with N=N bonds, such as azophenyl, azonaphthyl, aromatic heterocyclic azo, disazo, methyl

(formazan) group, and a group having an oxyazobenzene structure. The photoreactive group having a C=O bond includes, for example, a diphenyl ketone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid, halogenated alkyl and the like.

In terms of excellent alignment, a group that participates in a photodimerization reaction or a photocrosslinking reaction is preferable. In particular, the photoreactive group that participates in the photodimerization reaction is preferred. In terms of the photoalignment film that requires less polarized light irradiation for alignment and is easy to obtain thermal stability and excellent stability over time, cinnamonyl group And chalcone group is preferred. The polymer having a photoreactive group is particularly preferably one having a cinnamoyl group that becomes a cinnamic acid structure or a cinnamate ester structure at the end of the polymer side chain.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photoalignment film can be adjusted according to the type of polymer or monomer, and the thickness of the photoalignment film to be at least 0.2% by mass More preferably, it is more preferably in the range of 0.3 to 10% by mass.

As the method of applying the composition for forming a photoalignment film to a substrate, the same method as the method of applying a composition for forming a retardation layer to a substrate described later can be mentioned. As the method of removing the solvent from the coated photoalignment film-forming composition, the same method as the method of removing the solvent from the alignment polymer composition can be mentioned.

Irradiation of polarized light may be in the form of directly irradiating polarized light to the product obtained by removing the solvent from the composition for forming a photoalignment film coated on the substrate; it may also be a form of irradiating polarized light from the substrate side and allowing the polarized light to pass through the substrate. The form of exposure to materials. In addition, the polarized light is preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably a wavelength region in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet rays) having a wavelength of 250 nm to 400 nm is particularly preferable. Examples of light sources for irradiating the polarized light include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF, and the like. In particular, high-pressure mercury lamps, ultra-high pressure mercury lamps, and metal halide lamps are preferred because of the high luminous intensity of ultraviolet rays with a wavelength of 313nm. It is possible to irradiate polarized light UV by irradiating light from the aforementioned light source through an appropriate polarizing element. Examples of the polarizing element include polarizing filters, Glan-Thompson and Glan-Taylor polarizers, and metal wire grids. In particular, from the viewpoint of large area and resistance due to heat, A metal wire grid polarizer is preferred.

In addition, when performing polarized light irradiation, a plurality of regions (patterns) having different liquid crystal alignment directions can be formed by performing masking.

The groove (groove) alignment film is a film with a concave-convex pattern or a plurality of grooves on the film surface. When the polymerizable liquid crystal compound is coated on a film having a plurality of linear grooves arranged at equal intervals, the liquid crystal molecules are aligned along the direction of the grooves.

In terms of the method for obtaining the groove alignment film, there may be mentioned: after exposing the surface of the photosensitive polyimide film through an exposure mask having a pattern-shaped slit, developing and rinsing are performed to form a concave-convex pattern; A method of hardening after forming a layer of UV curable resin before curing on a plate-shaped master with grooves on the surface and transferring the resin layer to a substrate; and pressing the roll-shaped master with a plurality of grooves into contact with the substrate A method in which unevenness is formed on a UV-cured resin film before curing and then cured.

The thickness of the alignment film used to form the first retardation layer is usually in the range of 10 to 10000 nm, preferably in the range of 10 to 1000 nm, more preferably in the range of 50 to 500 nm.

The alignment film that forms the second phase difference layer is an alignment film that has alignment control force in the vertical direction (hereinafter also referred to as a vertical alignment film). For the vertical alignment film, it is better to use a material that can reduce the surface tension of the substrate surface. Examples of such materials include the aforementioned alignment polymers, fluorine-based polymers such as perfluoroalkyl groups, polyimide compounds, silane compounds, and polysiloxane compounds obtained through condensation reactions of these. A silane compound is preferable in terms of easily lowering the surface tension.

Silane compounds can be suitable for the silicone series such as the aforementioned silane coupling agent, such as vinyl trimethoxysilane, vinyl triethoxysilane, vinyl ginseng (2-methoxyethoxy) silane, N -(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxy 3-Glycidoxypropyltrimethoxysilane, 3-Glycidoxypropylmethyldimethoxysilane, 2-(3,4-Epoxycyclohexyl)ethyltrimethoxysilane Oxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethylsilane Oxysilane, 3-Glycidoxypropyltrimethoxysilane, 3-Glycidoxypropyltriethoxysilane, 3-Glycidoxypropyldimethoxymethylsilane, 3-Glycidoxypropylethoxydimethylsilane, etc. Two or more types of silane compounds can also be used.

The silane compound may be a silicone monomer type or a silicone oligomer (polymer) type. When the silicone oligomer is expressed as a (monomer)-(monomer) copolymer, the following examples can be given.

Such as 3-mercaptopropyl trimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyl trimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyl triethyl Oxysilane-tetramethoxysilane copolymer, and 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer and other mercaptopropyl-containing copolymers;

Such as mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane Oxysilane copolymer, and mercapto Copolymers containing mercaptomethyl groups such as methyltriethoxysilane-tetraethoxysilane copolymer;

Such as 3-methacryloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methyl Acryloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methylpropene Acyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methyl Acryloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer, etc. Copolymers containing methacryloxypropyl groups;

Such as 3-acryloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropyl Triethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropylmethyldimethoxy Silane-tetramethoxysilane copolymer, 3-acryloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropylmethyldiethoxysilane - Copolymers containing acryloxypropyl groups such as tetramethoxysilane copolymers and 3-acryloxypropylmethyldiethoxysilane-tetraethoxysilane copolymers;

Such as vinyl trimethoxysilane-tetramethoxysilane copolymer, vinyl trimethoxysilane-tetraethoxysilane copolymer, vinyl triethoxysilane-tetramethoxysilane copolymer, vinyl three Ethoxysilane- Tetraethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinylmethyldimethoxysilane-tetraethoxysilane copolymer, vinylmethyldimethoxysilane copolymer, vinylmethyldimethoxysilane Vinyl-containing copolymers such as oxysilane-tetramethoxysilane copolymer and vinylmethyldiethoxysilane-tetraethoxysilane copolymer;

Such as 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane Oxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyl Methyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-aminopropylmethyldiethoxysilane Amino-containing copolymers such as silane-tetraethoxysilane copolymer, etc.

In particular, a silane compound having an alkyl group at the end of the molecule is preferable, and a silane compound having an alkyl group having 6 to 20 carbon atoms is more preferable. Since these silane compounds are liquid in most cases, they can be directly applied to the substrate, or can be dissolved in a solvent and applied to the substrate. Also, it can be dissolved in a solvent together with various polymers as a binder and coated on the substrate.

As the method of applying the vertical alignment film to the substrate, the same method as the method of applying the retardation layer forming composition to the substrate described later can be mentioned. As the method of removing the solvent from the applied composition for forming a photoalignment film, the same method as the method of removing the solvent from the alignment polymer composition can be mentioned.

The thickness of the alignment film used to form the second retardation layer is usually in the range of 10 to 10000 nm, preferably in the range of 50 to 5000 nm, more preferably in the range of 100 to 500 nm.

<<Manufacturing method of retardation layer>>

<Coating of Retardation Layer Forming Composition>

The phase difference layer can be formed by applying the composition for phase difference layer formation on the said base material or an alignment film. As the method of coating the composition for retardation layer formation on the substrate, extrusion coating method, direct roll gravure coating (direct gravure coating) method, reverse gravure coating method, CAP coating method, etc. method, slit coating method, micro gravure method, die coating method, inkjet method, etc. Moreover, the method of coating using coaters, such as a dip coater, a bar coater, and a spin coater, etc. are also mentioned. In particular, when coating continuously in the form of Roll to Roll, it is preferable to use the microgravure method, inkjet method, slit coating method, and die coating method to coat. For materials, it is better to use the spin coating method with high uniformity.

<Drying of Retardation Layer Forming Composition>

Examples of drying methods for removing the solvent contained in the phase difference layer forming composition include natural drying, ventilation drying, heating drying, reduced-pressure drying, and a combination of these drying methods. In particular, natural drying or heating drying is preferred. The drying temperature is preferably in the range of 0 to 200°C, more preferably in the range of 20 to 150°C, more preferably in the range of 50 to 130°C. The drying time is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes. The composition for forming a photoalignment film and the alignment polymer composition can also be dried in the same manner.

<Polymerization of polymerizable liquid crystal compound>

The method of polymerizing the polymerizable liquid crystal compound is preferably photopolymerization. Photopolymerization can be implemented by irradiating active energy rays to a laminate in which a retardation layer-forming composition containing a polymerizable liquid crystal compound is applied on a substrate or an alignment film. The active energy ray to be irradiated can be determined according to the type of polymerizable liquid crystal compound contained in the dry film (especially the type of photopolymerizable functional group contained in the polymerizable liquid crystal compound), and the type of photopolymerization initiator when the photopolymerization initiator is included. , and their quantities are appropriately selected. Specifically, one or more kinds of light rays selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays can be used. In particular, in terms of the ease of controlling the progress of the polymerization reaction and the fact that it can be used as a photopolymerization device widely used in this field, ultraviolet light is preferred, and it is selected in a manner that can be photopolymerized by ultraviolet light. The kind of polymerizable liquid crystal compound is preferable.

The light sources of the above-mentioned active energy lines can be, for example, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and emission wavelengths ranging from 380 to 440 nm. LED light sources, fluorescent lamps for insect traps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc.

The ultraviolet irradiation intensity is usually 10 mW/cm ² to 3,000 mW/cm ² . The intensity of ultraviolet irradiation is preferably an intensity in a wavelength region effective for activating a cationic polymerization initiator or a radical polymerization initiator. The light irradiation time is usually 0.1 second to 10 minutes, preferably 0.1 second to 5 minutes, more preferably 0.1 second to 3 minutes, more preferably 0.1 second to 1 minute. When irradiated with such ultraviolet radiation intensity once or several times, the cumulative light intensity is 10mJ/cm ² to 3,000mJ/cm ² , preferably 50mJ/cm ² to 2,000mJ/cm ² , more preferably 100mJ/cm ² to 1,000 mJ/cm ² . When the integrated light quantity is less than this range, the curing of the polymerizable liquid crystal compound is insufficient, and favorable transferability may not be obtained. On the contrary, when the integrated light quantity is more than this range, the optical film system containing a retardation layer may be colored.

[polarizer]

The elliptically polarizing plate of the present invention is composed of a polarizing plate and the optical film of the present invention. and bonded to obtain the elliptically polarizing plate of the present invention.

In one embodiment of the present invention, when the polarizing plate is laminated with the optical film of the present invention, it is preferred to make the slow axis (optical axis) of the first retardation layer and the absorption axis of the polarizing plate substantially 45° layered in a manner. The function as a circular polarizing plate can be obtained by laminating so that the slow axis (optical axis) of the optical film of this invention and the absorption axis of a polarizing plate become substantially 45 degrees. Also, substantially 45° usually means a range of 45±5°.

The polarizer is composed of a polarizer with polarizing function. Examples of the polarizer include a stretched film on which an anisotropic absorption dye is adsorbed, or a film formed by coating and aligning an anisotropic absorption dye. Examples of dyes having absorption anisotropy include dichroic dyes.

The stretched film that absorbs the pigment with absorption anisotropy is usually produced through the following steps: a step of uniaxially stretching the polyvinyl alcohol-based resin film; a step of dyeing to adsorb the dichroic dye; a step of treating the polyvinyl alcohol-based resin film having the dichroic dye adsorbed thereon with an aqueous boric acid solution; and a step of washing with water after the treatment with the aqueous boric acid solution. A polarizing plate is obtained by bonding the polarizer obtained in this way to a transparent protective film. Examples of dichroic dyes include iodine and dichroic organic dyes. Examples of dichroic organic dyes include dichroic direct dyes composed of disazo compounds such as C.I. DIRECT RED 39 and dichroic direct dyes composed of compounds such as trisazo and tetrasazo. As described above, the thickness of a polarizer obtained by uniaxially stretching a polyvinyl alcohol-based resin film, dyeing with a dichroic dye, treating with boric acid, washing with water, and drying is preferably 5 μm to 40 μm.

[adhesive]

The adhesive used to attach the polarizing plate to the optical film of the present invention or the optical film of the present invention to a display device includes pressure-sensitive adhesives, dry-curable adhesives, and chemical reaction adhesives. Chemical reaction type adhesives include, for example, active energy ray hardening type adhesives. The adhesive between the polarizing plate and the optical film of the present invention is preferably an adhesive layer formed of a pressure-sensitive adhesive, a dry-curable adhesive, or an active energy ray-curable adhesive. The optical film of the present invention The adhesive between the display device and the display device is preferably a pressure-sensitive adhesive or an active energy ray hardening adhesive.

Pressure sensitive adhesives usually contain polymers and may also contain solvents.

Examples of polymers include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyethers, and the like. In particular, because of its excellent optical transparency, moderate wettability, cohesion, and excellent adhesion, Moreover, the weather resistance and heat resistance are high, and it is not easy to cause floating and peeling under the conditions of heating and humidification, so the acrylic adhesive containing acrylic polymer is the best.

Acrylic polymers are (meth)acrylates in which the alkyl group of the ester part is an alkyl group with a carbon number of 1 to 20 such as methyl, ethyl or butyl (hereinafter, acrylate and methacrylate are collectively referred to as In the case of (meth)acrylate, and acrylic acid and methacrylic acid are collectively referred to as (meth)acrylic acid) and (meth)acrylic acid, hydroxyethyl (meth)acrylate, etc. base) copolymers of acrylic monomers are preferred.

Because of its excellent adhesiveness, even if it is to be removed after bonding to the display device, there will be no adhesive residue on the display device, etc., and it can be removed relatively easily. Therefore, a pressure-sensitive adhesive containing such a copolymer is preferable. The glass transition temperature of the acrylic polymer is preferably below 25°C, more preferably below 0°C. The mass average molecular weight of such acrylic polymer is preferably more than 100,000.

As a solvent, the solvent etc. which were mentioned as the said solvent are mentioned. The pressure-sensitive adhesive may also contain a light diffusing agent. The light-diffusing agent is an additive that imparts light-diffusing properties to the adhesive, and may be fine particles that have a different refractive index from that of the polymer contained in the adhesive. As a light-diffusion agent, the microparticle which consists of an inorganic compound, and the microparticle which consists of an organic compound (polymer) are mentioned. Including acrylic polymers, most of the polymers contained in the adhesive as active ingredients have a refractive index of about 1.4 to 1.6, so it is better to properly select from light diffusing agents with a refractive index of 1.2 to 1.8. The polymer contained in the adhesive as an active ingredient and the light-expanding The refractive index difference of the powder is usually 0.01 or more, and preferably 0.01 to 0.2 from the viewpoint of the brightness and displayability of the display device. The microparticles used as the light diffusing agent are preferably not only spherical microparticles but also close to monodisperse microparticles, preferably with an average particle diameter of 2 μm to 6 μm. The refractive index is measured by the usual minimum declination method or Abbe's refractometer.

Examples of fine particles made of inorganic compounds include aluminum oxide (refractive index: 1.76) and silicon oxide (refractive index: 1.45). Microparticles composed of organic compounds (polymers) include melamine beads (refractive index 1.57), polymethyl methacrylate beads (refractive index 1.49), methyl methacrylate/styrene copolymer resin beads beads (refractive index 1.50 to 1.59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refractive index 1.46 ), and silicone resin beads (refractive index 1.46), etc. Content of a light-diffusion agent is 3 mass parts - 30 mass parts normally with respect to 100 mass parts of polymers.

Since the thickness of the pressure-sensitive adhesive is determined according to its adhesive force, etc., it is not particularly limited, and it is usually 1 μm to 40 μm. In terms of processability, durability, etc., the thickness is preferably 3 μm to 25 μm, more preferably 5 μm to 20 μm. By setting the thickness of the adhesive layer formed by the adhesive to 5 μm to 20 μm, the brightness of the display device can be maintained when viewing the display device from the front and when viewing the display device from an oblique view, and bleeding and blurring of the displayed image are less likely to occur.

[Dry curing type adhesive]

The dry-curable adhesive may contain a solvent.

Dry-curable adhesives include polymers or urethane resins containing monomers having protonic functional groups such as hydroxyl groups, carboxyl groups, or amine groups, and ethylenically unsaturated groups as main components, and polyaldehydes, cyclic Oxygen compounds, epoxy resins, melamine compounds, zirconia compounds, zinc compounds and other cross-linking agents or compositions of hardening compounds, etc. Polymers of monomers having protic functional groups such as hydroxyl, carboxyl, or amine groups and ethylenically unsaturated groups include ethylene-maleic acid copolymers, itaconic acid copolymers, and acrylic acid copolymers , acrylamide copolymer, saponified product of polyvinyl acetate, and polyvinyl alcohol-based resin, etc.

Polyvinyl alcohol-based resins include polyvinyl alcohol, partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, and methylol-modified polyvinyl alcohol. Alcohol, and amino-modified polyvinyl alcohol, etc. The content of the polyvinyl alcohol-based resin in the water-based adhesive is generally 1 to 10 parts by mass, preferably 1 to 5 parts by mass, relative to 100 parts by mass of water.

Examples of the urethane resin include polyester-based ionomer type urethane resins and the like.

The term "polyester-based ionomer type urethane resin" as used herein refers to a urethane resin having a polyester skeleton into which a small amount of ionic components (hydrophilic components) are introduced. Since such an ionomer type urethane resin is emulsified in water to form an emulsion without using an emulsifier, it can be used as a water-based adhesive. When using a polyester-based ionomer type urethane resin, it is effective to mix a water-soluble epoxy compound as a crosslinking agent.

Epoxy resins, can be cited to make epichlorohydrin Polyamide polyamines obtained by reacting polyalkylene polyamines such as triamine or triethylenetetramine with dicarboxylic acids such as adipic acid, and polyamide epoxy resins obtained by reacting them. Commercially available products of such polyamide epoxy resins include "Sumirez Resin (registered trademark) 650" and "Sumirez Resin 675" (above, manufactured by Sumika CHEMTEX Co., Ltd.), "WS-525" (Japan PMC Co., Ltd. company), etc. When preparing the epoxy resin, the amount of the epoxy resin added is usually 1 to 100 parts by mass, preferably 1 to 50 parts by mass, based on 100 parts by mass of the polyvinyl alcohol-based resin.

The thickness of the adhesive layer formed by the dry-curable adhesive is usually 0.001 μm to 5 μm, preferably 0.01 μm to 2 μm, more preferably 0.01 μm to 0.5 μm. When the adhesive layer formed by the dry-curable adhesive is too thick, for example, in an elliptical polarizing plate formed by a polarizing plate and the optical film of the present invention, poor appearance is likely to occur.

[Active energy ray hardening type adhesive]

The active energy ray-curable adhesive may contain a solvent. The so-called active energy ray-curable adhesive refers to an adhesive that is cured by irradiation with active energy rays.

Active energy ray-curable adhesives include the following adhesives: cationic polymerizable adhesives containing epoxy compounds and cationic polymerization initiators; radically polymerizable adhesives containing acrylic hardening components and radical polymerization initiators adhesives; adhesives containing both cationically polymerizable hardening components such as epoxy compounds and radically polymerizable hardening components such as acrylic compounds, and containing cationic polymerization initiators and radical polymerization initiators; and adhesives that do not contain such polymerizable Initiator, adhesive hardened by electron beam irradiation, etc.

In particular, it is a radically polymerizable active energy ray-curable adhesive containing an acrylic curing component and a radical polymerization initiator, and a cationically polymerizable active energy ray-curable adhesive containing an epoxy compound and a cationic polymerization initiator. Potion is better. Examples of the acrylic curing component include (meth)acrylates such as methyl (meth)acrylate and hydroxyethyl (meth)acrylate, and (meth)acrylic acid. The active energy ray-curable adhesive containing epoxy compounds may further contain compounds other than epoxy compounds. Examples of compounds other than epoxy compounds include oxetane compounds, acrylic compounds, and the like.

As a radical polymerization initiator, the photoinitiator mentioned above is mentioned. Commercially available cationic polymerization initiators include "KAYARAD" (registered trademark) series (manufactured by Nippon Kayaku Co., Ltd.), "Cyracure UVI" series (manufactured by DOW CHEMICAL), "CPI" series (manufactured by SAN-APRO Joint stock company), "TAZ", "BBI" and "DTS" (above, Midori Chemical Co., Ltd.), "ADEKA OPTOMER" series (ADEKA Co., Ltd.), "RHODORSIL" (registered trademark) (Rhodia Co., Ltd. )wait. The content of the radical polymerization initiator and the cationic polymerization initiator is usually 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass relative to 100 parts by mass of the active energy ray-curable adhesive.

The active energy ray hardening adhesive may further contain ion scavengers, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, and defoamers.

In this specification, the so-called active energy line is defined as the energy that can decompose the compound that produces the active species to generate the active species Wire. Examples of such active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays, and electron rays, among which ultraviolet rays and electron rays are preferred. Preferable irradiation conditions of ultraviolet rays are the same as those for the above-mentioned polymerization of the polymerizable liquid crystal compound.

[display device]

The present invention can provide a display device including the optical film of the present invention as one of the embodiments. In addition, the above-mentioned display device may include the elliptically polarizing plate of the above-mentioned embodiment.

The above-mentioned display device refers to a device having a display mechanism, and includes a light-emitting element or a light-emitting device as a light-emitting source. Display devices include liquid crystal display devices, organic electroluminescence (EL) display devices, inorganic electroluminescence (EL) display devices, touch panel display devices, electron emission display devices (field emission display devices (FED, etc.), Surface electric field emission display device (SED)), electronic paper (display device using electronic ink, electrophoretic moving element), plasma display device, projection display device (gating light valve (GLV; Grating Light Valve) display device, with Digital micromirror device (DMD; digital micromirror device) display device, etc.) and piezoelectric ceramic display, etc.

The liquid crystal display device includes any one of a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a projection type liquid crystal display device. These display devices may be display devices that display two-dimensional images, or may be stereoscopic display devices that display three-dimensional images. In particular, an organic EL display device and a touch panel display device are preferable for a display device including the optical film and polarizing plate composed of the present invention.

[Example]

Hereinafter, the present invention will be described more specifically by means of examples. In addition, "%" and "part" in an example mean mass % and a mass part unless it mentions otherwise. In addition, the polymer films, devices, and measurement methods used in the following examples are as follows.

‧Cycloolefin polymer (COP) film system uses ZF-14 manufactured by Japan ZEON Co., Ltd.

‧The corona treatment device is AGF-B10 manufactured by Kasuga Electric Co., Ltd.

‧Corona treatment was performed once using the above-mentioned corona treatment device under the conditions of output power 0.3kW and treatment speed 3m/min.

‧Polarized UV irradiation device uses SPOT CURE SP-9 with polarizer unit manufactured by USHIO Electric Co., Ltd.

‧The high-pressure mercury lamp is UNICURE VB-15201BY-A manufactured by USHIO Electric Co., Ltd.

‧The retardation value Re(λ) in the in-plane direction was measured using KOBRA-WPR manufactured by Oji Scientific Instruments Co., Ltd.

‧The retardation value Rth(λ) in the thickness direction and the film thickness were measured using an ellipsometer (ellipsometer) M-220 manufactured by JASCO Corporation.

[Preparation of Alignment Film Composition for Forming the First Retardation Layer]

The first phase was obtained by mixing 5 parts of the photo-alignment material (weight average molecular weight: 30000) and 95 parts of cyclopentanone (solvent) having the following structure as components, and stirring the resulting mixture at 80° C. for 1 hour Alignment film composition for poor layer formation.

[Preparation of alignment film composition for forming the second retardation layer]

A silane coupling agent KBE-9103 manufactured by Shin-Etsu Chemical Co., Ltd. was dissolved in a mixed solvent of ethanol and water at a ratio of 9:1 (by weight) to obtain a second retardation layer with a solid content of 1%. A composition for forming an alignment film.

[Composition modulation of first and second retardation layer formation (compositions I to IV)]

To the mixture of the polymerizable liquid crystal compound A and the polymerizable liquid crystal compound B described below, 0.1 parts of a leveling agent (F-556; manufactured by DIC Corporation) and a polymerization initiator 2-dimethylamino-2- Benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369 (Irg 369); manufactured by BASF Japan Co., Ltd.) 6 parts.

And by adding N-methyl-2-pyrrolidone (NMP) as a solvent so that the solid content concentration becomes 13%, and stirring at 80 degreeC for 1 hour, the formation of the 1st and 2nd retardation layer was obtained Use composition. In addition, the mixture ratio of the polymerizable liquid crystal compound A and the polymerizable liquid crystal compound B was added as described in Table 1 according to the target wavelength dispersion value α, and the names of the respective compositions were as described in Table 1.

※聚合性液晶化合物A、及B的比率，係設為相對於聚合性液晶化合物總量之比率。 [Table 1]

※The ratio of the polymerizable liquid crystal compound A and B is the ratio relative to the total amount of the polymerizable liquid crystal compound.

The polymerizable liquid crystal compound A was produced by the method described in JP-A-2010-31223. In addition, the polymerizable liquid crystal compound B was produced according to the method described in JP 2009-173893. The respective molecular structures are shown below.

Polymeric Liquid Crystal Compound A

Polymeric Liquid Crystal Compound B

[The composition of the liquid crystal composition for the formation of the first and second retardation layers system (composition V)]

To the following liquid crystal compound LC242: PaliocolorLC242 (registered trademark of BASF Corporation), 0.1 part of leveling agent F-556 and 3 parts of polymerization initiator Irg369 were added, and cyclopentanone was added so that the solid content concentration became 13%. Thus, the first and second liquid crystal compositions for retardation layer formation were obtained. Let the name of the obtained liquid crystal composition be "composition V".

Liquid crystal compound LC242: Paliocolor LC242 (registered trademark of BASF Corporation)

(Example 1)

[Manufacturing of the first retardation layer]

The first alignment film composition for retardation layer formation was coated on a COP film (ZF-14-50) manufactured by Japan ZEON Co., Ltd. using a bar coater, dried at 80° C. for 1 minute, and irradiated with polarized light UV With a device (SPOT CURE SP-9; manufactured by USHIO Electric Co., Ltd.), the cumulative light amount at a wavelength of 313 nm: 100 mJ/cm ² and polarized UV exposure was performed at an axial angle of 45°. The film thickness of the obtained alignment film for forming a first retardation layer was measured using an ellipsometer, and it was 100 nm.

Next, the composition I was coated on the alignment film for forming the first retardation layer using a bar coater, dried at 120° C. for 1 minute, and then sprayed by using a high-pressure mercury lamp (UNICURE VB-15201BY-A, manufactured by USHIO Electric Co., Ltd. ) was irradiated with ultraviolet rays (accumulated light intensity at a wavelength of 365 nm under a nitrogen atmosphere: 500 mJ/cm ² ) from the surface side of the composition on which the retardation layer was applied to form a first retardation layer. As a result of measuring the film thickness of the obtained first retardation layer using an ellipsometer, it was 2.3 μm.

[Manufacturing of the second retardation layer]

The alignment film composition for forming the second retardation layer was coated on a COP film (ZF-14-50) manufactured by ZEON Co., Ltd. in Japan using a bar coater, and dried at 120° C. for 1 minute to obtain the second phase Alignment film for poor layer formation. As a result of measuring the film thickness of the obtained alignment film for forming a second retardation layer using an ellipsometer, it was 200 nm.

Next, the composition I was coated on the alignment film for forming the second retardation layer using a bar coater, dried at 120° C. for 1 minute, and then sprayed by using a high-pressure mercury lamp (UNICURE VB-15201BY-A, manufactured by USHIO Electric Co., Ltd. ) was irradiated with ultraviolet rays (accumulated light intensity at a wavelength of 365 nm in a nitrogen atmosphere: 500 mJ/cm ² ) from the surface side of the composition on which the retardation layer was applied to form a second retardation layer. As a result of measuring the film thickness of the obtained second retardation layer using an ellipsometer, it was 1.2 μm.

[Measurement of Re of the first retardation layer and the second retardation layer]

The in-plane retardation values (Re1(λ) and Re2(λ)) of the first retardation layer and the second retardation layer manufactured by the above method are determined by confirming that the cycloolefin polymer film system of the substrate has no retardation Thereafter, measurement was performed at wavelengths λ of 450 nm, 550 nm, and 650 nm using a measuring machine (KOBRA-WR, manufactured by Oji Scientific Instruments). The obtained results are shown in Table 2.

[Rth measurement of the first retardation layer and the second retardation layer]

The retardation values in the thickness direction (Rth1(λ) and Rth2(λ)) of the first retardation layer and the second retardation layer manufactured by the above method are determined by confirming that the cycloolefin polymer film system of the substrate has no retardation Afterwards, using an ellipsometer and changing It is determined by the incident angle of light on the sample. In addition, the average refractive index at the wavelength λ of 450 nm and 550 nm was measured using the refractometer ("multi-wavelength Abbe refractometer DR-M4" by ATAGO Co., Ltd.). Table 2 shows Rth1(λ) and Rth2(λ) at wavelengths λ of 450 nm and 550 nm calculated from the obtained film thickness, average refractive index, and ellipsometer measurement results.

[Calculation of Nz(λ)]

Nz(λ) of the optical film obtained by laminating the first retardation layer and the second retardation layer was calculated based on Equation (C). The calculated results are shown in Table 2.

Also, the refractive indices nx1(λ), ny1(λ) and nz1(λ) of the obtained first retardation layer satisfy nx1(λ)>ny1(λ)≒ in the whole range of wavelength λ=400 to 700nm nz1(λ). In addition, the refractive indices nx2(λ), ny2(λ) and nz2(λ) of the second retardation layer satisfy nz2(λ)>nx2(λ)≒ny2(λ) in the entire range of wavelength λ=400 to 700 nm .

[production of polarizing plate]

A polyvinyl alcohol film with an average degree of polymerization of about 2,400, a saponification degree of 99.9 mol% or more, and a thickness of 75 μm is immersed in pure water at 30°C, and then immersed in an iodine/potassium iodide/water weight ratio of 0.02/2/ 100 aqueous solution for iodine staining (iodine staining step). The polyvinyl alcohol film after the iodine dyeing step was immersed in an aqueous solution with a weight ratio of potassium iodide/boric acid/water of 12/5/100 at 56.5° C. for boric acid treatment (boric acid treatment step). The polyvinyl alcohol film after the boric acid treatment step was washed with pure water at 8°C, and then dried at 65°C to obtain a polarizer with iodine adsorption and alignment on polyvinyl alcohol (thickness after stretching 27 μm). At this time, elongation is performed in the iodine staining step and the boric acid treatment step. The total extension ratio in this extension was 5.3 times. The obtained polarizer and a saponified cellulose triacetate film (KC4UYTAC 40 μm, manufactured by Konica Minolta) were bonded together using a nip roller via a water-based adhesive. The obtained bonded product was dried at 60° C. for 2 minutes while maintaining the tension of 430 N/m, and a polarizing plate having a cellulose triacetate film as a protective film on one side was obtained. Also, the above-mentioned water-based adhesive is 100 parts of water, 3 parts of carboxy-modified polyvinyl alcohol (KURARAY POVAL KL318 manufactured by KURARAY), water-soluble polyamide epoxy resin (Sumirez Resin 650 manufactured by Sumika CHEMTEX, 30% concentration of solid content) are added. Aqueous solution] 1.5 parts and preparation.

The optical characteristics were measured about the obtained polarizing plate. The measurement was carried out using a spectrophotometer (V7100, manufactured by JASCO Corporation) with the polarizer surface of the polarizing plate obtained above being the incident surface. The obtained sensitivity-corrected monomer transmittance was 42.1%, the sensitivity-corrected polarization degree was 99.996%, the monomer hue a was -1.1, and the monomer hue b was 3.7.

[Manufacture of elliptical polarizer]

First, after corona treatment was applied to the surface of the first retardation layer, the polarizing plate manufactured by the above-mentioned method was bonded via an adhesive (pressure-sensitive adhesive manufactured by Lintec Co., Ltd., 5 μm), and then the substrate was peeled off to form a polarized light. A laminate of a plate and a first retardation layer.

Next, after performing corona treatment on the surface of the second retardation layer, the first retardation layer, and the second retardation layer. Subsequently, the substrate was peeled off to manufacture an elliptically polarizing plate.

[Confirmation of frontal hue and oblique hue change]

After bonding the obtained elliptically polarizing plate to a mirror via an adhesive, the hue was confirmed by visual observation at a position 50 cm away from the front. In addition, oblique hues were confirmed by visual observation at a position separated by 50 cm from an elevation angle of 60° and an azimuth angle of 0 to 360°. The confirmed results are shown in Table 2.

Also, the positive hue and oblique hue are as follows.

◎: Clear black, ○: Black, △: Red or bluish black, ×: Red or blue

(Examples 2 to 30, Comparative Examples 1 to 12)

An optical film and an elliptically polarizing plate were produced in the same manner as in Example 1, except that the composition I was changed to the composition II, composition III, composition IV, or composition V according to the description in Table 2. Table 2 shows the respective measurement results.

In addition, the refractive indices nx1(λ), ny1(λ) and nz1(λ) of the first retardation layer obtained in Examples 2 to 30 satisfy nx1(λ)> ny1(λ)≒nz1(λ). In addition, the refractive indices nx2(λ), ny2(λ) and nz2(λ) of the second retardation layer satisfy nz2(λ)>nx2(λ)≒ny2(λ) in the entire range of wavelength λ=400 to 700 nm.

(Example 31)

In addition to changing the composition I according to the description in Table 2, and changing the lamination order of the first retardation layer and the second retardation layer in the manufacturing method of the elliptically polarizing plate to the polarizing plate and the second retardation layer first After lamination, the lamination body of the polarizing plate and the second retardation layer and the sequence of the lamination layer of the first retardation layer Except for the procedures, an optical film and an elliptically polarizing plate were manufactured in the same manner as in Example 1. The measurement results are shown in Table 2.

In addition, the refractive indices nx1(λ), ny1(λ) and nz1(λ) of the first retardation layer obtained in Example 31 satisfy nx1(λ)>ny1(λ) in the entire range of wavelength λ=400 to 700 nm ≒nz1(λ). In addition, the refractive indices nx2(λ), ny2(λ) and nz2(λ) of the second retardation layer satisfy nz2(λ)>nx2(λ)≒ny2(λ) in the entire range of wavelength λ=400 to 700 nm.

[Table 2]

The elliptically polarizing plate having the first retardation layer and the second retardation layer described in the examples has a front hue and an oblique hue that are black and has excellent antireflection properties.

Claims (14)

An optical film is provided with a first retardation layer and a second retardation layer and satisfies the relationship of the following formulas (1) and (2), 0.4≦Nz(450)≦0.6 (1) 0.4≦Nz(550)≦0.6 (2) In the formula, Nz(450) represents the Nz coefficient of the optical film to the light of wavelength λ=450nm, Nz(550) represents the Nz coefficient of the optical film to the light of wavelength λ=550nm, and the optical film to the wavelength λ (nm) The Nz coefficient Nz(λ) of light is given by Nz(λ)=(nx(λ)-nz(λ))/(nx(λ)-ny(λ)) Indicates; nx(λ) means in the refractive index ellipsoid formed by the optical film, for the light of wavelength λ (nm), the main refractive index in the direction parallel to the film plane; ny(λ) means the optical film formed In the refractive index ellipsoid, for the light of wavelength λ (nm), the refractive index in the direction parallel to the film plane and orthogonal to the nx (λ) direction; nz(λ) means that in the refractive index ellipsoid formed by the optical film, for the light of wavelength λ (nm), the refractive index in the direction perpendicular to the film plane; The aforementioned first retardation layer is a film composed of a coating layer formed by polymerizing polymerizable liquid crystals in an aligned state; The aforementioned polymerizable liquid crystals are thermotropic liquid crystals; The aforementioned first retardation layer system: In the range of wavelength λ=400 to 700nm in the refractive index ellipsoid formed by the first retardation layer, there is a relationship of nx1(λ)>ny1(λ)≒nz1(λ), In the formula, nx1(λ) means that in the refractive index ellipsoid formed by the first retardation layer, for the light of wavelength λ (nm), the main refractive index in the direction parallel to the film plane; ny1(λ) means In the refractive index ellipsoid formed by the first retardation layer, the refractive index for light rays of wavelength λ (nm) in the direction parallel to the film plane and orthogonal to the direction of the aforementioned nx1 (λ); nz1 (λ) is Represents the refractive index in the direction perpendicular to the film plane for light of wavelength λ (nm) in the refractive index ellipsoid formed by the first retardation layer; And satisfy the relationship of the following formulas (3) and (4), Re1(450)/Re1(550)≦1.00 (3) 1.00≦Re1(650)/Re1(550) (4) In the formula, Re1(450) represents the in-plane retardation value of the first retardation layer for the light of wavelength λ=450nm, Re1(550) represents the surface of the first retardation layer for the light of wavelength λ=550nm The internal retardation value, Re1(650) means the in-plane retardation value of the first retardation layer for the light of wavelength λ=650nm, and the in-plane retardation value of the first retardation layer for the light of wavelength λnm Re1( λ) is based on Re1(λ)=(nx1(λ)-ny1(λ))×d1 Indicates that, here, d1 represents the thickness of the first retardation layer. The optical film as described in item 1 of the scope of the patent application, wherein the second retardation layer is: In the range of wavelength λ=400 to 700nm in the refractive index ellipsoid formed by the second retardation layer, there is a relationship of nz2(λ)>nx2(λ)≒ny2(λ), In the formula, nz2(λ) means that in the refractive index ellipsoid formed by the second retardation layer, for the light of wavelength λ (nm), the refractive index in the direction perpendicular to the film plane; nx2(λ) means that in In the refractive index ellipsoid formed by the second phase difference layer, for the light of wavelength λ (nm), the maximum refractive index in the direction parallel to the film plane; ny2(λ) means the refractive index formed in the second phase difference layer In the ellipsoid, in the direction parallel to the film plane and perpendicular to the direction of nx2 mentioned above, the refractive index of light with wavelength λ (nm); but when nx2(λ)=ny2(λ), nx2(λ) is Indicates the refractive index in any direction parallel to the film plane; And satisfy the relationship of the following formulas (5) and (6), Rth2(450)/Rth2(550)≦1.00 (5) 1.00≦Rth2(650)/Rth2(550) (6) In the formula, Rth2(450) represents the retardation value in the thickness direction of light with wavelength λ=450nm, and Rth2(550) represents the retardation value in the thickness direction of the second retardation layer for light with wavelength λ=550nm , Rth2 (650) represents the retardation value in the thickness direction of the second retardation layer to the light of wavelength 650nm, and the retardation value Rth2( λ) is based on Rth2(λ)=[(nx2(λ)+ny2(λ))/2-nz2(λ)]×d2 Indicates that, here, in the refractive index ellipsoid formed by the second retardation layer, nz2(λ) represents the main refractive index in the direction perpendicular to the film plane at the wavelength λ(nm), ((nx2(λ)+ ny2(λ))/2) represents the average refractive index of the film plane at the wavelength λ (nm), and d2 represents the thickness of the second retardation layer. The optical film as described in item 1 or 2 of the scope of the patent application, wherein, the A phase difference layer system further satisfies the relationship of the following formula (7), 120nm≦Re1(550)≦170nm (7) In the formula, Re1(550) represents the in-plane retardation value of the first retardation layer for the light of wavelength λ=550nm. The optical film as described in any one of items 1 to 3 of the scope of application, wherein the second retardation layer further has the optical properties shown in formula (8), -100nm≦Rth2(550)≦-50nm (8) In the formula, Rth2(550) represents the retardation value in the thickness direction of the second retardation layer for the light of wavelength λ=550nm. The optical film as described in any one of claims 1 to 4 of the patent claims, wherein the second retardation layer is composed of a coating layer formed by polymerizing polymerizable liquid crystals in an aligned state membrane. The optical film according to any one of claims 1 to 5, wherein the second retardation layer is 5 μm or less. The optical film according to any one of claims 1 to 6, wherein the first retardation layer is 5 μm or less. The optical film as described in any one of claims 1 to 7 of the patent claims, wherein the first retardation layer and the second retardation layer are coated by polymerizing the same polymerizable liquid crystal compound as the main layer. An elliptically polarizing plate with optical compensation function, comprising the optical film and polarizing plate described in any one of items 1 to 8 of the scope of the patent application. Ellipse with optical compensation function as described in item 9 of the patent application A polarizing plate, wherein the absorption axis of the polarizing plate and the slow axis of the first retardation layer have a relationship of 45±5° or 135±5° in the film plane, and the absorption axis of the polarizing plate and the slow axis of the first retardation layer The axis is perpendicular to the slow axis of the second retardation layer in the vertical direction to the film surface. The elliptical polarizer with optical compensation function as described in item 9 or 10 of the scope of the patent application is formed with a polarizer, an adhesive layer, a first retardation layer, an adhesive layer, and a second retardation layer in sequence Optical laminates. The elliptical polarizer with optical compensation function as described in item 9 or 10 of the scope of the patent application is formed with a polarizer, an adhesive layer, a second retardation layer, an adhesive layer, and a first retardation layer in sequence Optical laminates. An organic EL display device is equipped with an elliptical polarizer with an optical compensation function described in any one of items 10 to 12 of the scope of application. A manufacturing method of an elliptically polarizing plate with optical compensation function, which is the manufacturing method of an elliptically polarizing plate with optical compensation function described in any one of items 9 to 12 of the scope of the patent application comprising the following steps, (Step 1-A) A step of forming a first phase difference layer by polymerizing a polymerizable liquid crystal compound in a horizontally aligned state after coating the substrate on which the horizontal alignment film is formed; (Step 1-B) a step of forming a second retardation layer by polymerizing the polymerizable liquid crystal compound in a vertically aligned state after coating the substrate on which the vertical alignment film is formed; and (Step 2) A step of transferring the liquid crystal polymer of the first retardation layer and the liquid crystal polymer of the second retardation layer from the base material via an adhesive agent, and laminating them on the polarizing plate.