TW201905119A - Optical anisotropic layer and manufacturing method thereof, optical anisotropic stack, multilayer for transfer, polarizing plate, and image display device - Google Patents

Abstract

An optically anisotropic layer containing a positive C-type polymer and a polymerization product of a mesogenic compound, wherein the mesogenic compound is a compound having a mesogenic backbone and an acrylate structure, and the optically anisotropic layer satisfies the requirement represented by the formula: 0.073 < AC-H/AC=O (mesogenic compound) < 0.125. AC-H represents an infrared absorption associated with the out-of-plane bending vibration of a C-H bond in the acrylate structure in infrared absorption spectra of the optically anisotropic layer; and AC=O (mesogenic compound) represents the sum total of an infrared absorption associated with the stretching vibration of a C=O bond in the acrylate structure and an infrared absorption associated with the stretching vibration of a C=O bond derived from the C=O bond in the acrylate structure in infrared absorption spectra of the optically anisotropic layer. The production of an optically anisotropic layer, and a use of the optically anisotropic layer.

Description

Optically anisotropic layer and manufacturing method thereof, optically anisotropic stack, multilayer for transfer, polarizing plate, and image display device

The present invention relates to an optically anisotropic layer and a method for manufacturing the same; an optically anisotropic stack including the optically anisotropic layer; and a transfer multilayer, a polarizing plate, and an image display device including the optically anisotropic layer. .

Various optical films are provided in image display devices such as liquid crystal display devices and organic electroluminescence display devices. Hereinafter, "organic electroluminescence" will be referred to as "organic EL" in due course. The technology of such an optical film has been studied in the past (for example, Patent Documents 1 and 2).

"Patent Literature" "Patent Literature 1": Japanese Patent Publication No. 2015-14712 "Patent Literature 2": Japanese Patent Publication No. 2015-57646 (corresponding publication: US Patent Application Publication No. 2015/041051)

A circular polarizing plate is provided on a display surface of the image display device. As the circular polarizing plate, an optical film including a linear polarizer and an optically anisotropic layer is generally used. Since the circular polarizing plate is arranged on the display surface of the image display device, when the display surface is viewed from the front, the reflection of external light can be suppressed, and the light of the displayed image can penetrate the polarized sunglasses, so the visibility of the image can be improved. Sex.

The effect of the circular polarizing plate may be damaged when the display surface is viewed from an oblique direction. In order to improve the effect of viewing the display surface from an oblique direction, consider the combination of a positive C film and a circular polarizer. The positive-type C film used in this application is preferably a film exhibiting inverse wavelength dispersion by retardation Rth in the thickness direction. Such a positive-type C film can be manufactured by considering a manufacturing method using a liquid crystal compound as described in Patent Documents 1 and 2, for example.

However, in the conventional technology, it is not easy to produce a positive-type C film in which the retardation Rth in the thickness direction exhibits inverse wavelength dispersion. For example, in the method using an alignment film like the manufacturing method using a liquid crystal compound described in Patent Documents 1 and 2, it is required to adjust the compatibility of the alignment film and the liquid crystal compound, so the adjustment is complicated. In addition, since the number of steps for applying the alignment film to the substrate is increased, the use of the alignment film may cause an increase in cost. In addition, optical films used in image display devices also require various characteristics other than wavelength dispersion. For example, high durability and good color tone are required for optical films. In the conventional technology, a positive C film having a reverse wavelength dispersion Rth may deteriorate such durability and hue. For example, when the optical film is generally required to reduce the degradation caused by long-term use in a high-temperature environment, the positive type C film with reverse wavelength dispersion Rth in the prior art is a result of long-term use in a high-temperature environment. Defects such as rising haze and cloudiness occur. In addition, when the optical film is generally required to have no deviation in transmittance and reflectance due to the wavelength of light and the color tone is close to colorless, the positive type C film with reverse wavelength dispersion Rth in the prior art still has a color tone that is not colorless. In the case of yellow and other tones.

Therefore, an object of the present invention is to provide an optically anisotropic layer that is "a C-plate that can be manufactured without using an alignment film and exhibits inverse wavelength dispersion in retardation Rth in the thickness direction, and has high durability". And a multilayer multilayer for transfer including the optically anisotropic layer, a method for manufacturing the multilayer multilayer, an optically anisotropic stack including the optical anisotropic layer, a multilayer for transfer, a polarizing plate, and an image display device.

The present invention is as follows.

[1] An optically anisotropic layer, which is an optically anisotropic layer containing a positive C polymer, a mesogen compound, and a polymer of a mesogen compound, and the positive C polymer is used by In the case where the film of the positive C polymer is formed by the coating method of the solution of the positive C polymer, the film satisfies the polymer of the formula (1), and the liquid crystal compound is a compound having a liquid crystal skeleton and an acrylate structure. , The foregoing optically anisotropic layer satisfies the formulas (2) and (3): nz (P)> nx (P) ≧ ny (P) Formula (1) nz (A)> nx (A) ≧ ny (A) Formula (2) 0.073 <A _{C - H} / A _{C = O} (liquid crystal compound) <0.125 Formula (3) wherein nx (P), ny (P) and nz (P) are the main refractive indices of the aforementioned film, nx (a), ny (a ) and nz (a) based principal refractive index of the optical anisotropic layer, a _{C - H} in the infrared absorption spectrum system the optically anisotropic layer, the compound of the aforementioned mesogen Infrared absorption related to out-of-plane bending vibration of the C-H bond of the acrylate structure, A _{C = O} (liquid crystal compound) is based on the aforementioned optical anisotropy In the infrared absorption spectrum of the layer, the infrared absorption related to the stretching vibration of the C = O bond of the aforementioned acrylate structure of the aforementioned mesogen compound and the C = O bond of the aforementioned acrylate structure derived from the aforementioned mesogen compound The sum of infrared absorption related to the stretching vibration of the C = O bond of the junction.

[2] The optically anisotropic layer according to [1], wherein the mesogen compound is a compound that exhibits in-plane retardation of inverse wavelength dispersion when uniformly aligned.

[3] The optically anisotropic layer as described in [1] or [2], which satisfies the formulas (4) and (5): 0.50 <Rth (A450) / Rth (A550) <1.00 Formula (4) 1.00 ≦ Rth (A650) / Rth (A550) <1.25 Formula (5) where Rth (A450) is the retardation of the aforementioned optically anisotropic layer in the thickness direction of the wavelength of 450 nm, and Rth (A550) is the aforementioned optically anisotropic layer The retardation in the thickness direction of the wavelength 550 nm, Rth (A650) is the retardation in the thickness direction of the wavelength of 650 nm of the aforementioned optically anisotropic layer.

[4] The optically anisotropic layer according to any one of [1] to [3], wherein the aforementioned mesogen compound is represented by the following formula (I): "Chemical 1" (In the formula (I): Y ¹ to Y ⁸ each independently represent a chemical single bond, -O-, -S-, -O-C (= O)-, -C (= O) -O- , -O-C (= O) -O-, -NR ¹ -C (= O)-, -C (= O) -NR ^1- , -O-C (= O) -NR ^1- , -NR ¹ -C (= O) -O-, -NR ¹ -C (= O) -NR ^1- , -O-NR ¹ -or -NR ¹ -O-; here, R ¹ represents a hydrogen atom or a carbon number 1 to 6 alkyl groups; G ¹ and G ² each independently represent a divalent aliphatic group having 1 to 20 carbon atoms which may have a substituent; and each of the aliphatic groups in the aforementioned aliphatic group may be interposed by One or more of -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O-C (= O) -O-, -NR ² -C (= O)-, -C (= O) -NR ^2- , -NR ² -or -C (= O)-; among them, the case where two or more of -O- or -S- are adjacent and intermediary respectively is excluded; here, R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms of; the Z ¹ and Z ² each independently represent a halogen atom can also be substituted by an alkenyl group having a carbon number of 2 to 10; a ^x represents an aromatic hydrocarbon ring selected from the group consisting of aryl and At least one of the groups formed by heterocycles An aromatic group having 2 to 30 carbons; A ^y represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may also have a substituent, and A cycloalkyl group having 3 to 12 carbon atoms which may have a substituent, an alkynyl group having 2 to 20 carbon atoms which may have a substituent, -C (= O) -R ³ , -SO ₂ -R ⁴ , -C ( = S) NH-R ⁹ or an organic group having 2 to 30 carbon atoms in at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring; Here, R ³ represents a carbon that may have a substituent. Alkyl group having 1 to 20, alkenyl group having 2 to 20 carbon atoms which may have a substituent, cycloalkyl group having 3 to 12 carbon atoms or aromatic hydrocarbon ring group having 5 to 12 carbon atoms which may have a substituent; ⁴ represents an alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, phenyl group, or 4-methylphenyl group; R ⁹ represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or Alkenyl having 2 to 20 carbons having a substituent, cycloalkyl having 3 to 12 carbons having a substituent, or aryl having 5 to 20 carbons having a substituent; the aforementioned A ^x and A ^y has an aromatic ring may have a substituent; and the a ^x and a ^y may together form ; A ¹ represents a trivalent aromatic group may have a substituent; A ² and A ³ may each independently represent a substituent having a carbon number of 3 to 30 divalent alicyclic hydrocarbon group; A ⁴ and A ⁵ independently represent and also A bivalent aryl group having 6 to 30 carbon atoms which may have a substituent; Q ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may also have a substituent; m and n each independently represent 0 or 1; wherein, Z Either one or both of ¹ -Y ⁷ -and -Y ⁸ -Z ² is acryloxy).

[5] The optically anisotropic layer according to any one of [1] to [4], wherein the aforementioned mesogen compound contains in its molecular structure a member selected from the group consisting of "benzothiazole ring" and "cyclohexyl ring and A combination of benzene rings ".

[6] The optically anisotropic layer according to any one of [1] to [5], wherein the positive C polymer is selected from the group consisting of polyvinylcarbazole, polyfumarate, and cellulose A polymer of at least one of the groups.

[7] The optically anisotropic layer according to any one of [1] to [6], wherein a ratio of the aforementioned liquid crystalline original compound and its polymer in a total solid content of the optically anisotropic layer is 20 weight % Or more and 60% by weight or less.

[8] The optically anisotropic layer described in [1] to [7], which satisfies the formulas (6) and (7): Re (A590) ≦ 10 nm Formula (6) −200 nm ≦ Rth (A590 ) ≦ -10 nm Formula (7) where Re (A590) is the retardation of the aforementioned optical anisotropic layer at a wavelength of 590 nm, and Rth (A590) is the thickness of the aforementioned optical anisotropic layer in the thickness direction of 590 nm. delay.

[9] A multilayer material for transfer, comprising a substrate and the optically anisotropic layer according to any one of [1] to [8].

[10] An optically anisotropic stacked body including the optically anisotropic layer and the retardation layer according to any one of [1] to [8], wherein the retardation layer satisfies an expression (8): nx ( B)> ny (B) ≧ nz (B) Formula (8) wherein nx (B), ny (B), and nz (B) are the main refractive indexes of the retardation layer.

[11] The optically anisotropic stack as described in [10], wherein the retardation layer satisfies the formulas (9) and (10): 0.75 <Re (B450) / Re (B550) <1.00 Formula (9) 1.01 <Re (B650) / Re (B550) <1.25 Formula (10) where Re (B450) is the retardation of the aforementioned retardation layer at a wavelength of 450 nm, and Re (B550) is the aforementioned retardation layer at a wavelength of 550 nm In-plane retardation, Re (B650) is an in-plane retardation of the aforementioned retardation layer at a wavelength of 650 nm.

[12] The optically anisotropic stacked body according to [11], wherein the retardation layer includes a liquid crystal compound for a retardation layer represented by the following formula (II): "Chem 2" (In the aforementioned formula (II): Y ¹ to Y ⁸ each independently represent a chemical single bond, -O-, -S-, -O-C (= O)-, -C (= O) -O- , -O-C (= O) -O-, -NR ¹ -C (= O)-, -C (= O) -NR ^1- , -O-C (= O) -NR ^1- , -NR ¹ -C (= O) -O-, -NR ¹ -C (= O) -NR ^1- , -O-NR ¹ -or -NR ¹ -O-; here, R ¹ represents a hydrogen atom or a carbon number 1 to 6 alkyl groups; G ¹ and G ² each independently represent a divalent aliphatic group having 1 to 20 carbon atoms which may have a substituent; and each of the aliphatic groups in the aforementioned aliphatic group may be interposed by One or more of -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O-C (= O) -O-, -NR ² -C (= O)-, -C (= O) -NR ^2- , -NR ² -or -C (= O)-; among them, the case where two or more of -O- or -S- are adjacent and intermediary respectively is excluded; Here, R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Z ¹ and Z ² each independently represent an alkenyl group having 2 to 10 carbon atoms which may be substituted by a halogen atom; and A ^x represents a compound selected from an aromatic hydrocarbon ring and an aromatic group. Heterocyclic group Aromatic ring having a carbon number of an organic group of 2 to 30; A ^y represents a hydrogen atom, can be a substituent having a carbon number of alkyl group of 1 to 20, also having a carbon number of the substituent of the alkenyl group having 2 to 20, also A cycloalkyl group having 3 to 12 carbon atoms which may have a substituent, an alkynyl group having 2 to 20 carbon atoms which may have a substituent, -C (= O) -R ³ , -SO ₂ -R ⁴ , -C ( = S) NH-R ⁹ or an organic group having 2 to 30 carbon atoms in at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring; Here, R ³ represents a carbon that may have a substituent. An alkyl group having 1 to 20, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 3 to 12 carbon atoms or an aromatic hydrocarbon ring group having 5 to 12 carbon atoms which may have a substituent; R ⁴ represents an alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, phenyl group, or 4-methylphenyl group; R ⁹ represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or Alkenyl having 2 to 20 carbons having a substituent, cycloalkyl having 3 to 12 carbons having a substituent, or aryl having 5 to 20 carbons having a substituent; the aforementioned A ^x and A ^y has an aromatic ring may have a substituent; and the a ^x and a ^y may together form ; A ¹ represents a trivalent aromatic group may have a substituent; A ² and A ³ may each independently represent a substituent having a carbon number of 3 to 30 divalent alicyclic hydrocarbon group; A ⁴ and A ⁵ independently represent and also A bivalent aryl group having 6 to 30 carbons which may have a substituent; Q ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbons which may also have a substituent; m and n each independently represent 0 or 1).

[13] A polarizing plate comprising: a linear polarizer; and the optically anisotropic layer according to any one of [1] to [8], the multilayer material for transfer according to [9], or The optically anisotropic stack according to any one of [10] to [12].

[14] An image display device including the polarizing plate according to [13].

[15] An image display device comprising: the optically anisotropic stack as described in any one of [10] to [12]; a linear polarizer; and an image display element; the image display element is a liquid crystal Unit or organic electroluminescent element.

[16] A method for producing an optically anisotropic layer according to any one of [1] to [8], comprising: preparing a positive-type C polymer, a mesogen, a solvent, and a photopolymerization initiator And a step of applying a coating liquid of a crosslinking agent; a step of applying the coating liquid on a support surface to obtain a coating liquid layer; and a step of irradiating the coating liquid layer with light to cure the coating liquid layer.

[17] The method for producing an optically anisotropic layer according to [16], wherein in the coating liquid, a ratio of the photopolymerization initiator to 100 parts by weight of the mesogen compound is 1 to 10 parts by weight The proportion of the cross-linking agent to 100 parts by weight of the mesogen compound is 1 to 10 parts by weight.

[18] The manufacturing method according to [16] or [17], wherein an integrated light amount of the aforementioned light to be irradiated is 600 mJ / cm ² to 5000 mJ / cm ² .

According to the present invention, there is provided an optically anisotropic layer "which can be manufactured without using an alignment film, and exhibits inverse wavelength dispersion in the retardation Rth in the thickness direction, a positive type C plate having high durability and a good hue" and the aforementioned optical An anisotropic layer transfer multilayer, a method for manufacturing the same, an optically anisotropic stack including the optically anisotropic layer, a transfer multilayer, a polarizing plate, and an image display device.

The embodiments and examples are disclosed below to explain the present invention in detail. However, the present invention is not limited to the implementation types and examples shown below, and can be arbitrarily changed and implemented without departing from the scope of the patent application of the present invention and its equivalent scope.

In the following description, unless otherwise noted, the frontal direction of a surface means the normal direction of the surface, which specifically refers to the direction in which the polar angle of the aforementioned surface is 0 ° and the azimuth angle is 0 °.

In the following description, unless otherwise noted, the inclination direction of a surface means a direction that is neither parallel nor perpendicular to the surface, and specifically refers to a direction in which the polar angle of the aforementioned surface is greater than 0 ° and less than 90 °. .

In the following description, unless otherwise noted, the in-plane retardation Re of a layered body is a value represented by Re = (nx-ny) × d, and the retardation Rth in the thickness direction of a layered body is represented by Rth = ｛[(Nx + ny) / 2]-The value represented by nz｝ × d. Here, nx represents the refractive index which belongs to the in-plane direction of the layer body and gives the direction of maximum refractive index, ny represents the refractive index which belongs to the aforementioned in-plane direction of the layer body and is orthogonal to the nx direction, and nz represents the The refractive index in the thickness direction, d represents the thickness of the layer. The in-plane direction means a direction perpendicular to the thickness direction.

In the following description, unless otherwise noted, the measurement wavelength of the refractive index is 590 nm.

In the following description, the so-called "long-shaped" member refers to a member having a length which is usually 5 times or more with respect to the width, preferably 10 times or more in length, and specifically means "having a rollable member" Length to the extent that it is stored or transported in rolls ". The upper limit of the length of the long member is not particularly limited, and is set to, for example, 100,000 times or less the width.

In the following description, the "polarizing plate" and "wavelength plate" include not only rigid members but also members having flexibility such as a resin film.

In the following description, unless otherwise noted, "(meth) acrylic acid" includes the terms "acrylic acid", "methacrylic acid", and combinations thereof.

In the following description, the directions of the requirements are "parallel" and "vertical". Unless otherwise noted, within the range that does not impair the effect of the present invention, an error within the range of ± 5 ° may be included.

In the following description, a resin having a positive intrinsic birefringence value means a resin having a refractive index extending in a direction greater than a refractive index orthogonal to the direction. In addition, a resin having a negative intrinsic birefringence value means a resin having a refractive index in an extending direction that is smaller than a refractive index orthogonal to the direction. The intrinsic birefringence is worth calculating from the Dielectric constant distribution.

In the following description, the main refractive index of a layer body or film means the refractive index nx belonging to the in-plane direction of the layer body and the direction giving the maximum refractive index, the in-plane direction belonging to the layer body, and perpendicular to the "given The refractive index ny in the direction of the aforementioned “nx direction” and the refractive index nz in the thickness direction of the layer. In this application, the refractive indices corresponding to these nx, ny, and nz are represented by symbols including the strings "nx", "ny", and "nz", respectively. For example, among the principal refractive indices nx (A), ny (A), and nz (A) of the optically anisotropic layer, nx (A) belongs to the in-plane direction of the optically anisotropic layer and gives the maximum refractive index The refractive index in the direction of ny (A) is the refractive index that belongs to the in-plane direction of the optically anisotropic layer and is perpendicular to the direction of "the direction given to nx (A)". Refractive index in the thickness direction.

In the following description, the in-plane retardation Re of a layered body exhibits inverse wavelength dispersion, which means that the in-plane retardation Re (450) and Re (550) of the layered body satisfy Re (450) / Re (550) <1.00. Re has a layer with inverse wavelength dispersion. It is preferable that the layer retards Re (550) and Re (650) in the plane of the wavelengths of 550 nm and 650 nm to further satisfy Re (550) / Re (650) <1.00.

The retardation Rth in the thickness direction of a layer indicates the inverse wavelength dispersion. It means that the retardation Rth (450) and Rth (550) of the layer in the thickness direction of the wavelength 450 nm and 550 nm satisfy Rth (450) / Rth ( 550) <1.00. Rth has a layer with inverse wavelength dispersion. It is preferable that the retardation of the layer in the thickness direction of the wavelengths 550 nm and 650 nm Rth (550) and Rth (650) further satisfy Rth (550) / Rth (650) <1.00 .

[1. Optically Anisotropic Layer]

The optically anisotropic layer of the present invention includes a positive C polymer, a mesogen compound, and a polymer of a mesogen compound, and has specific optical characteristics.

[1.1. Positive C polymer]

The positive C polymer is a polymer, and in the case where a polymer film is formed by a coating method using a solution of the polymer, the film satisfies the formula (1). nz (P)> nx (P) ≧ ny (P) Formula (1) where nx (P), ny (P), and nz (P) are the main refractive indices of the film. By using such a positive C polymer in combination with a mesogen compound, it is possible to realize optical components that "can be manufactured without using an alignment film and used as a positive C plate that exhibits reverse wavelength dispersion with retardation Rth in the thickness direction". Anisotropic layer.

Whether a polymer conforms to the positive C polymer can be confirmed by the following method.

First, a polymer as a sample was added to methyl ethyl ketone (MEK), 1,3-dioxy, N-methylpyrrolidone (NMP) so that the polymer concentration was 10 to 20% by weight. ) And other solvents to dissolve it at room temperature to obtain a polymer solution.

This polymer solution was applied to an unstretched film made of a resin using an applicator to form a layer of the polymer solution. Thereafter, the solvent was evaporated by drying in an oven at 85 ° C. for about 10 minutes to obtain a polymer film having a thickness of about 10 μm.

Then, it is evaluated whether the refractive index nx (P), the refractive index ny (P), and the refractive index nz (P) of the polymer film satisfy the formula (1). If it is satisfied, the polymer as the sample can be determined as Conforms to positive C polymer.

The refractive index nx (P) and the refractive index ny (P) are preferably the same or close to each other. Specifically, the difference nx (P) -ny (P) between the refractive index nx (P) and the refractive index ny (P) is preferably 0.00000 to 0.00100, more preferably 0.00000 to 0.00050, and even more preferably 0.00000 to 0.00020. . When the refractive index difference nx (P) -ny (P) falls within the foregoing range, the optically anisotropic layer of the present invention can be easily obtained.

As a positive C polymer, in the case where a positive C polymer film is formed by a coating method using a solution of the positive C polymer, "this film has a refractive index satisfying the aforementioned formula (1)" Of any polymer. Among them, as the positive C polymer, at least one polymer selected from the group consisting of "polyvinylcarbazole, polyfumarate, and cellulose derivatives" is preferred. By using these polymers as the positive C polymer, an optically anisotropic layer having a large retardation Rth in the thickness direction can be easily obtained by coating.

Examples of the polyvinyl carbazole include a polymer containing a polymerized unit obtained by polymerizing 9-vinyl carbazole.

Examples of the polyfumarate include a copolymer of diisopropyl fumarate and 3-ethyl-3-oxomethyl acrylate; and fumarate di Copolymer of isopropyl ester and cinnamate.

The positive C polymer may be used singly or in combination of two or more kinds in any ratio.

The proportion of the positive C polymer in the total solid content of the optically anisotropic layer is preferably 30% by weight or more, more preferably 35% by weight or more, most preferably 40% by weight or more, and 60% by weight or less. Preferably, it is more preferably 55% by weight or less, and most preferably 50% by weight or less. With the proportion of the positive C polymer being above the lower limit of the aforementioned range, the mesogen compound can be uniformly dispersed in the optically anisotropic layer, and the mechanical strength of the optically anisotropic layer can be improved. Below the upper limit of the range, the wavelength dispersion of the retardation Rth in the thickness direction of the optically anisotropic layer can be made close to the reverse dispersion. Here, the solid content of a layered body refers to a component remaining when the layered body is dried.

[1.2. Mesogen compounds]

In the present application, a mesogen compound is a compound having a mesogen skeleton and an acrylate structure.

The so-called mesogen framework possessed by the mesogen compound means a molecular skeleton that essentially contributes to the generation of a liquid crystal phase in a low-molecular weight or high-molecular-weight substance through the anisotropy of the interaction between its gravitational force and repulsion. The mesogen compound containing the mesogen skeleton may not necessarily have liquid crystallinity in which a phase transition to a liquid crystal phase can occur. Therefore, the mesogen compound may be a liquid crystal compound that undergoes a phase transition to a liquid crystal phase in a single state, or a non-liquid crystal compound that does not undergo a phase transition to a liquid crystal phase in a single state. Examples of the original liquid crystal skeleton include rigid rod-shaped or disc-shaped cells. For the original liquid crystal framework, please refer to: Pure Appl. Chem. 2001, Vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, Vol. 116, 6340-6368 page.

In the optically anisotropic layer, the alignment state of the mesogen compound can also be fixed. For example: the mesogen compound can also be polymerized to fix the alignment state of the mesogen compound. Since the mesogen compound is usually polymerized through polymerization, it becomes a polymer while maintaining the alignment state of the mesogen compound. Therefore, the alignment state of the mesogen compound is fixed by the aforementioned polymerization. Therefore, the term "a liquid crystal compound having an aligned state fixed" includes a polymer of a liquid crystal compound. Therefore, in the case where the mesogen compound is a liquid crystal compound having liquid crystallinity, the liquid crystal compound may exhibit a liquid crystal phase in the optically anisotropic layer, or may not exhibit a liquid crystal phase by being immobilized in an alignment state.

As the aforementioned mesogen compound, an inverse wavelength dispersive liquid crystal compound, an inverse wavelength mesogen compound, or a combination thereof can be used.

Here, the reverse wavelength dispersion liquid crystal compound means a compound that satisfies all of the following requirements (i) and (ii). (I) Inverse wavelength dispersion liquid crystal compounds exhibit liquid crystallinity. (Ii) In-plane retardation in which the inverse wavelength dispersion liquid crystal compound exhibits inverse wavelength dispersion under uniform alignment.

The inverse wavelength mesogen compound means a compound that satisfies all of the following requirements (iii), (iv), and (v). (Iii) The inverse wavelength mesogen compound does not exhibit liquid crystallinity in a single state. (Iv) A specific evaluation mixture containing a reverse-wavelength mesogen compound exhibits liquid crystallinity. (V) In the case where the aforementioned mixture for evaluation is uniformly aligned, the inverse wavelength mesogen compound exhibits in-plane retardation of inverse wavelength dispersion.

The aforementioned mixture for evaluation refers to "mixing the aforementioned inverse wavelength mesogen compound with at least any ratio of 30 parts by weight to 70 parts by weight with respect to 100 parts by weight of the total liquid crystal compound for evaluation and the inverse wavelength mesogen compound. A mixture of liquid crystal compounds for evaluation of in-plane retardation that exhibits forward wavelength dispersion in the case of uniform alignment ".

By using such a mesogen compound in combination with a positive C polymer, it is possible to realize optical components that can be manufactured without the use of an alignment film and used as a positive C plate that exhibits reverse wavelength dispersion with retardation Rth in the thickness direction. Anisotropic layer.

The inverse wavelength dispersion liquid crystal compound will be described below.

When the inverse wavelength dispersion liquid crystal compound is uniformly aligned, it exhibits in-plane retardation of inverse wavelength dispersion. Here, the so-called uniform alignment of the liquid crystal compound refers to forming a layer body containing the liquid crystal compound, and aligning the long axis direction of the original liquid crystal skeleton of the molecules of the liquid crystal compound in the layer body parallel to the plane of the layer body. A certain direction. In the case where the liquid crystal compound includes a plurality of types of mesogens having different alignment directions, the direction in which the longest type of mesogens are aligned is the aforementioned alignment direction. Whether the liquid crystal compound is uniformly aligned and its alignment direction can be obtained by measuring the slow axis direction using a phase difference meter such as that represented by AxoScan (manufactured by Axometrics), and measuring the retardation distribution of each incident angle in the slow axis direction. Measurement ".

In the case where a liquid crystal layer containing a liquid crystal compound with inverse wavelength dispersion is formed and the major axis direction of the mesogen of the molecules of the liquid crystal compound in this layer is aligned to a certain direction parallel to the surface of the liquid crystal layer, the liquid crystal The in-plane retardation Re (L450) and Re (L550) of the layer at the wavelengths of 450 nm and 550 nm usually satisfy Re (L450) / Re (L550) <1.00.

Furthermore, the in-plane retardations Re (L450), Re (L550), and Re (L650) of the aforementioned liquid crystal layer at the wavelengths of 450 nm, 550 nm, and 650 nm make the desired effects of the present invention exhibit better. From a viewpoint, it is preferable to satisfy Re (L450) <Re (L550) ≦ Re (L650).

As the inverse-wavelength dispersive liquid crystal compound, for example, a compound including "a molecule of the inverse-wavelength dispersive liquid crystal compound including a main-chain liquid crystal protoskeleton and a side-chain liquid crystal protoskeleton bonded to the main-chain liquid crystal protoskeleton" can be used. The aforementioned reverse-wavelength dispersive liquid crystal compound including a main-chain liquid crystal protoskeleton and a side-chain liquid crystal pro-skeleton. In the state where the reverse-wavelength dispersive liquid-crystal compound is aligned, the side-chain liquid crystal pro-skeleton may be aligned to be different from the main-chain liquid crystal pro-skeleton. Direction. In this case, the birefringence system is exhibited as the difference between the "refractive index corresponding to the original skeleton of the main chain liquid crystal" and the "refractive index corresponding to the original skeleton of the side chain liquid crystal", so as a result, the inverse wavelength dispersion liquid crystal compound is uniformly aligned In this case, in-plane retardation with inverse wavelength dispersion can be exhibited.

For example, the aforementioned compounds having a main-chain mesogen skeleton and a side-chain mesogen skeleton, the inverse-wavelength dispersive liquid crystal compound usually has a specific three-dimensional shape different from that of a general forward-wavelength dispersive liquid crystal compound. Here, the "forward-wavelength dispersion liquid crystal compound" refers to a liquid crystal compound that exhibits in-plane retardation that exhibits forward-wavelength dispersion in the case of uniform alignment. In addition, the in-plane retardation with forward wavelength dispersion means that the in-plane retardation becomes smaller as the measurement wavelength becomes larger. The case where the inverse wavelength dispersion liquid crystal compound has such a specific three-dimensional shape is presumed to be a factor that can obtain the effect of the present invention.

The CN point of the inverse wavelength dispersion liquid crystal compound is preferably 25 ° C or higher, more preferably 45 ° C or higher, particularly 60 ° C or higher, and preferably 120 ° C or lower, preferably 110 ° C or lower, 100 Below ℃ is particularly preferred. The so-called "CN point" here refers to the temperature of crystallization-nematic phase transition. By using a reverse wavelength dispersion liquid crystal compound having a CN point in the aforementioned range, an optically anisotropic layer can be easily manufactured.

The molecular weight of the reverse-wavelength dispersive liquid crystal compound, when it is a monomer, is preferably 300 or more, more preferably 700 or more, more preferably 1000 or more, and preferably 2000 or less, and more preferably 1700 or less. Especially preferred is 1500 or less. By having a reverse-wavelength dispersive liquid crystal compound having a molecular weight as described above, the coatability of the coating liquid used to form the optically anisotropic layer can be optimized in particular.

The aforementioned inverse wavelength dispersion liquid crystal compound may be used singly or in combination of two or more kinds in any ratio.

Examples of the inverse wavelength dispersion liquid crystal compound include those described in Japanese Patent Laid-Open No. 2014-123134. In addition, examples of the inverse wavelength dispersion liquid crystal compound include compounds exhibiting liquid crystallinity among the compounds represented by the following formula (Ia). In the following description, the compound represented by formula (Ia) is referred to as "compound (Ia)" as appropriate.

『Hua 3』

In the aforementioned formula (Ia), A ^1a represents: an aromatic hydrocarbon ring group having "an organic group having 1 to 67 carbon atoms in at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles" as a substituent; Alternatively, it is an aromatic heterocyclic group having "an organic group having 1 to 67 carbon atoms in at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring" as a substituent.

As a specific example of A ^1a , it can be given by "by the formula: -R ^f C [= N-N (R ^g ) R ^h ] or by the formula: -R ^f C [= N-N = C (R ^g1 ) " ^Rh ] is a" phenyl "substituted phenyl group; a benzothiazole-4,7-diyl group substituted with a 1-benzofuran-2-yl group; and a 5- (2-butyl) -1-benzene group Benzofuran-2-yl substituted benzothiazole-4,7-diyl; 4,6-dimethyl-1-benzofuran-2-yl substituted benzothiazole-4,7-diyl; Benzothiazole-4,7-diyl substituted with 6-methyl-1-benzofuran-2-yl; substituted with 4,6,7-trimethyl-1-benzofuran-2-yl Benzothiazole-4,7-diyl; benzothiazole-4,7-diyl substituted with 4,5,6-trimethyl-1-benzofuran-2-yl; 5-methyl- 1-benzofuran-2-yl-substituted benzothiazole-4,7-diyl; 5-propyl-1-benzofuran-2-yl-substituted benzothiazole-4,7-diyl; 7-propyl-1-benzofuran-2-yl substituted benzothiazole-4,7-diyl; 5-fluoro-1-benzofuran-2-yl substituted benzothiazole-4, 7-diyl; benzothiazole-4,7-diyl substituted with phenyl; benzothiazole-4,7-diyl substituted with 4-fluorophenyl; benzene substituted with 4-nitrophenyl Benzothiazole-4,7-diyl; via 4-tris Methylphenyl substituted benzothiazole-4,7-diyl; 4-cyanophenyl substituted benzothiazole-4,7-diyl; 4-methylsulfonylphenyl substituted benzothiazole- 4,7-diyl; thiothien-2-yl substituted benzothiazole-4,7-diyl; thiophen-3-yl substituted benzothiazole-4,7-diyl; 5-methylthiophene -2-yl substituted benzothiazole-4,7-diyl; 5-chlorothien-2-yl substituted benzothiazole-4,7-diyl; thiophene [3,2-b] thiophene- 2-yl substituted benzothiazole-4,7-diyl; 2-benzothiazyl-substituted benzothiazole-4,7-diyl; 4-biphenyl-substituted benzothiazole-4, 7-diyl; benzothiazole-4,7-diyl substituted with 4-propylbiphenyl; benzothiazole-4,7-diyl substituted with 4-thiazolyl; 1-phenylethylene 2-yl-substituted benzothiazole-4,7-diyl; 4-pyridyl-substituted benzothiazole-4,7-diyl; 2-furanyl-substituted benzothiazole-4,7- Diyl; benzothiazole-4,7-diyl substituted with naphthalene [1,2-b] furan-2-yl; 1H-isoindole substituted with 5-methoxy-2-benzothiazolyl -1,3 (2H) -dione-4,7-diyl; 1H-isoindole-1,3 (2H) -dione-4,7-diyl substituted by phenyl; 4-nitro Phenyl-substituted 1H-isoindole-1,3 (2H) -dione-4,7-diyl; or 2-thiazolyl-substituted 1H-isoindole-1,3 (2H) -dione -4,7-diyl; etc. Here, R ^f has the same meaning as Q ¹ described later. R ^g and R ^g1 each independently have the same meaning as A ^y described later, and R ^h has the same meaning as A ^x described later.

In the aforementioned formula (Ia), Y ^1a to Y ^8a each independently represent a chemical single bond, -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O-C (= O) -O-, -NR ¹ -C (= O)-, -C (= O) -NR ^1- , -O-C (= O) -NR ^1- , -NR ¹ -C (= O) -O-, -NR ¹ -C (= O) -NR ^1- , -O-NR ¹ -or -NR ¹ -O-. Here, R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In the formula (Ia), G ^1a and G ^2a each independently represent a divalent aliphatic group having 1 to 20 carbon atoms which may have a substituent. In addition, each of the aliphatic groups on the aforementioned aliphatic group may also interpose more than one -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O- C (= O) -O-, -NR ² -C (= O)-, -C (= O) -NR ^2- , -NR ² -or -C (= O)-. Among them, it is excluded that two or more -O- or -S- are adjacent and intermediary respectively. Here, R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In the formula (Ia), Z ^1a and Z ^2a each independently represent an alkenyl group having 2 to 10 carbon atoms which may be substituted by a halogen atom.

In the formula (Ia), A ^2a and A ^3a each independently represent a divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms which may have a substituent.

In the formula (Ia), A ^4a and A ^5a each independently represent a divalent aryl group having 6 to 30 carbon atoms which may have a substituent.

In the formula (Ia), k and l each independently represent 0 or 1.

However, in the aforementioned formula (Ia), one or both of Z ^1a -Y ^7a -and -Y ^8a -Z ^2a is an acryloxy group.

As a particularly suitable specific example of the reverse wavelength dispersion liquid crystal compound, a compound exhibiting liquid crystallinity among the compounds represented by the following formula (I) is mentioned. In the following description, the compound represented by formula (I) is referred to as "compound (I)" as appropriate.

『Hua 4』

The compound (I) is generally represented by the following formula, and includes "by the group -Y ⁵ -A ⁴ -Y ^3- (A ² -Y ¹ ) _n -A ^1- (Y ² -A ³ ) _m -Y ^4- A ⁵ -Y ⁶ -formed main chain liquid crystal original skeleton 1a "and" side chain liquid crystal original skeleton 1b made of base> A ^1- C (Q ¹ ) = N-N (A ^x ) A ^{y "} "The two original liquid crystal skeletons. The main-chain mesogen 1a and the side-chain mesogen 1b cross each other. Although it is also possible to combine the above-mentioned main chain liquid crystal original skeleton 1a and the side chain liquid crystal original skeleton 1b to form one original liquid crystal skeleton, the present invention is divided into two original liquid crystal skeletons.

『Hua 5』

The refractive index of the main chain liquid crystal original skeleton 1a in the long axis direction is set to n1, and the refractive index of the side chain liquid crystal original skeleton 1b in the long axis direction is set to n2. At this time, the absolute value of the refractive index n1 and the wavelength dispersion property generally depend on the molecular structure of the main-chain liquid crystal protoskeleton 1a. In addition, the absolute value of the refractive index n2 and the wavelength dispersion are generally determined by the molecular structure of the side chain mesogen 1b. Here, the compound (I) in the liquid crystal phase usually rotates with the long axis direction of the main chain liquid crystal original skeleton 1a as the rotation axis. Therefore, the refractive indexes n1 and n2 referred to herein represent the refraction as a rotating body. rate.

Due to the molecular structure of the main chain liquid crystal original skeleton 1a and the side chain liquid crystal original skeleton 1b, the absolute value of the refractive index n1 is larger than the absolute value of the refractive index n2. In addition, the refractive indices n1 and n2 usually exhibit forward wavelength dispersion. Here, the refractive index with forward wavelength dispersion means a refractive index with a smaller absolute value of the refractive index as the measurement wavelength is larger. The refractive index n1 of the main chain liquid crystal original skeleton 1a exhibits a small degree of forward wavelength dispersion. Therefore, the refractive index n1 measured at a long wavelength is smaller than the refractive index measured at a short wavelength, but the difference is small. In contrast, the refractive index n2 of the side chain mesogen skeleton 1b exhibits a large degree of forward wavelength dispersion. Therefore, the refractive index n2 measured at a long wavelength is smaller than the refractive index n2 measured at a short wavelength, and the difference is large. Therefore, if the measurement wavelength is short, the difference Δn between the refractive index n1 and the refractive index n2 is small, and if the measurement wavelength is long, the difference Δn between the refractive index n1 and the refractive index n2 is large. In this way, due to the main-chain mesogen 1a and the side-chain mesogen 1b, the compound (I) exhibits in-plane retardation exhibiting inverse wavelength dispersion in the case of uniform alignment.

In the formula (I), Y ¹ to Y ⁸ each independently represent a chemical single bond, -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O-C (= O) -O-, -NR ¹ -C (= O)-, -C (= O) -NR ^1- , -O-C (= O) -NR ^1- , -NR ¹ -C (= O) -O-, -NR ¹ -C (= O) -NR ^1- , -O-NR ¹ -or -NR ¹ -O-. Here, R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In the formula (I), G ¹ and G ² each independently represent a divalent aliphatic group having 1 to 20 carbon atoms which may have a substituent. In addition, each of the aliphatic groups on the aforementioned aliphatic group may also interpose more than one -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O- C (= O) -O-, -NR ² -C (= O)-, -C (= O) -NR ^2- , -NR ² -or -C (= O)-. Among them, it is excluded that two or more -O- or -S- are adjacent and intermediary respectively. Here, R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In the formula (I), Z ¹ and Z ² each independently represent an alkenyl group having 2 to 10 carbon atoms which may be substituted by a halogen atom.

In the formula (I), A ^x represents an organic group having 2 to 30 carbon atoms in at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring. "Aromatic ring" means a cyclic structure with a generalized aromaticity following the Hückel's rule, that is, a cyclic conjugate structure with (4n + 2) π electrons, and thiophene, furan, and benzothiazole The lone electron pairs of heteroatoms represented by sulfur, oxygen, nitrogen, etc. participate in the π-electron system and show an aromatic ring structure.

Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring. Examples of the aromatic heterocyclic ring include monocyclic aromatic heterocyclic rings such as a pyrrole ring, a furan ring, a thiophene ring, a pyridine ring, a data ring, a pyrimidine ring, a pyridine ring, a pyrazole ring, an imidazole ring, an oxazole ring, and a thiazole ring. ; Benzothiazole ring, benzoxazole ring, quinoline ring, fluorene ring, benzimidazole ring, benzopyrazole ring, benzofuran ring, benzothiophene ring, thiazopyridine ring, oxazolopyridine ring , Thiazolopyridyl ring, oxazolopyridyl ring, thiazolopridyl ring, oxazolopridyl ring, thiazolopyrimidine ring, oxazolopyrimidine ring and other fused ring aromatic heterocycles.

In the formula (I), A ^y represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, or a carbon which may also have a substituent. Cycloalkyl having 3 to 12 or alkynyl having 2 to 20 carbons which may have a substituent, -C (= O) -R ³ , -SO ₂ -R ⁴ , -C (= S) NH-R ⁹ or an organic group having 2 to 30 carbon atoms in at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring. Here, R ³ represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, and a cycloalkane having 3 to 12 carbon atoms which may also have a substituent. Or an aromatic hydrocarbon ring group having 5 to 12 carbon atoms. R ⁴ represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a phenyl group, or a 4-methylphenyl group. R ⁹ represents an alkyl group having 1 to 20 carbons which may have a substituent, an alkenyl group having 2 to 20 carbons which may have a substituent, a cycloalkyl group having 3 to 12 carbons which may also have a substituent, or An aryl group having 5 to 20 carbon atoms which may have a substituent. The A ^x and A ^y has an aromatic ring may have a substituent. In addition, the aforementioned A ^x and A ^y may form a ring together.

In the formula (I), A ¹ represents a trivalent aryl group which may have a substituent.

In the formula (I), A ² and A ³ each independently represent a divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms which may have a substituent.

In the formula (I), A ⁴ and A ⁵ each independently represent a divalent aryl group having 6 to 30 carbon atoms which may have a substituent.

In the formula (I), Q ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.

In the formula (I), m and n each independently represent 0 or 1.

In the aforementioned formula (I), one or both of Z ¹ -Y ⁷ -and -Y ⁸ -Z ² are propylene alkoxy groups.

Specific examples of the compound (I) include compounds described in International Patent Publication No. 2016/171169, International Patent Publication No. 2017/057005, and International Patent Publication No. 2016/190435. The production of the compound (I) is carried out by the methods described in these documents.

Next, the inverse wavelength mesogen compound will be described.

The inverse wavelength mesogen compound is a compound that "does not exhibit liquid crystallinity in a single state, but exhibits liquid crystallinity in an evaluation mixture after mixing with a liquid crystal compound for evaluation in a specific mixing ratio". As the liquid crystal compound for evaluation, a forward-wavelength dispersive liquid crystal compound is used which is a "liquid-crystal compound that exhibits in-plane retardation exhibiting forward-wavelength dispersibility in the case of uniform alignment". By using the forward-wavelength dispersive liquid crystal compound as the liquid crystal compound for evaluation, it is possible to easily perform the evaluation of the wavelength dispersion of the in-plane retardation of the inverse-wavelength original liquid crystal compound when the evaluation mixture is uniformly aligned. Among them, the liquid crystal compound for evaluation is preferably a liquid crystal compound having a rod-like structure having a liquid crystal phase at 100 ° C. As a specific example of a particularly preferable liquid crystal compound for evaluation, a forward-wavelength dispersive liquid crystal compound (Paliocolor (registered trademark) LC242 (manufactured by BASF)) having a structure disclosed in the following formula (E1) may be mentioned and disclosed in A forward-wavelength dispersive liquid crystal compound having a structure of the formula (E2). In the following formula, Me represents a methyl group.

『Hua 6』

『Hua 7』

In addition, the mixing ratio of the inverse wavelength mesogen compound to be mixed with the liquid crystal compound for evaluation in order to obtain the evaluation mixture is usually 30 parts by weight to 70 with respect to 100 parts by weight of the total of the liquid crystal compound for evaluation and the inverse wavelength mesogen compound. At least any one part by weight. Therefore, as long as the "reverse wavelength mesogen compound is contained in at least one mixing ratio" contained in a range of 30 parts by weight to 70 parts by weight with respect to 100 parts by weight of the total liquid crystal compound for evaluation and the inverse wavelength mesogen compound ", and The liquid crystallinity-evaluating mixture is mixed with the inverse wavelength at another mixing ratio of "contained in the range of 30 parts by weight to 70 parts by weight with respect to 100 parts by weight of the total liquid crystal compound for evaluation and the inverse wavelength mesogen compound". The mixture obtained by the mesogen compound may not exhibit liquid crystallinity.

When the liquid crystallinity of the mixture for evaluation was shown, it was confirmed by the following method.

The evaluation mixture was applied to a substrate and dried to obtain a sample film including a layered body of the substrate and the evaluation mixture. This sample film was set on a hot stage. The sample film was observed through a polarizing microscope while the sample film was warmed. When a phase transition of the layer body of the evaluation mixture to a liquid crystal phase is observed, it can be determined that the evaluation mixture exhibits liquid crystallinity.

When the aforementioned evaluation mixture is uniformly aligned, the inverse wavelength mesogen compound in this evaluation mixture exhibits in-plane retardation of inverse wavelength dispersion. Here, uniformly aligning the evaluation mixture means forming a layer of the evaluation mixture and uniformly aligning the liquid crystal compound for evaluation in the layer. Therefore, in the evaluation mixture that has been uniformly aligned, the major axis direction of the original mesogen skeleton of the molecules of the liquid crystal compound for evaluation is usually aligned in a direction parallel to the plane of the layer.

In addition, the so-called "in-plane retardation of the inverse wavelength mesogen compound in the uniformly aligned evaluation compound exhibiting inverse wavelength dispersion" means that the inverse wavelength mesogen compound contained in the evaluation mixture has a wavelength of 450 nm and 550 nm. The in-plane retardations Re (450) and Re (550) satisfy Re (450) / Re (550) <1.00.

However, in the layered body of the evaluation mixture, it is difficult to selectively measure only the in-plane retardation of the inverse wavelength mesogen compound. Then, by using the liquid crystal compound for evaluation as a forward-wavelength dispersion liquid crystal compound, it was confirmed that the inverse-plane retardation of the inverse-wavelength original liquid crystal compound in the evaluation-use mixture exhibited inverse-wavelength dispersion by the following confirmation method.

A liquid crystal layer containing a liquid crystal compound for evaluation that is a liquid crystal compound with a forward wavelength dispersion is formed, and the liquid crystal compound for evaluation is uniformly aligned in the liquid crystal layer. Then, the ratio Re (X450) / Re (X550) of the in-plane retardation Re (X450) and Re (X550) of the liquid crystal layer at the wavelengths of 450 nm and 550 nm was measured.

Then, a layered body containing the evaluation mixture of the liquid crystal compound for evaluation and the inverse-wavelength mesogen compound is formed, and the evaluation mixture is uniformly aligned in the layered body of the evaluation mixture. Then, the ratio Re (Y450) / Re (Y550) of the in-plane retardation Re (Y450) and Re (Y550) of the layer of the mixture for evaluation at the wavelengths of 450 nm and 550 nm was measured.

As a result of the measurement, "the retardation ratio Re (X450) / Re (X550) of the liquid crystal layer not including the inverse wavelength mesogen compound is smaller than" the retardation ratio Re (X) of the layer body including the inversion wavelength mesogen compound. When Y450) / Re (Y550) "is small, this inverse wavelength mesogen compound can be determined as an in-plane retardation exhibiting inverse wavelength dispersion.

In addition, from the viewpoint of making the desired effect of the present invention more satisfactory, in the aforementioned confirmation method, the in-plane retardation Re (Y550) of the layered body of the mixture for evaluation at wavelengths of 550 nm and 650 nm And Re (Y650) ratio Re (Y650) / Re (Y550) "is greater than the ratio of the in-plane retardation Re (X550) and Re (X650) of the liquid crystal layer at wavelengths 550 nm and 650 nm Re (X650) / Re (X550) "is preferred.

As the inverse wavelength mesogen compound, for example, a compound including "a molecule of the inverse wavelength mesogen compound including a main chain mesogen skeleton and a side chain mesogen skeleton bonded to the aforementioned main chain mesogen" can be used.

In addition, the inverse wavelength mesogen is preferably polymerizable. Therefore, the inverse wavelength mesogen is preferably a polymerizable group. By using such a polymerizable inverse wavelength mesogen compound, the alignment state of the inverse wavelength mesogen compound can be easily fixed by polymerization. Therefore, an optically anisotropic layer having stable optical characteristics can be easily obtained.

The molecular weight of the inverse wavelength mesogen is preferably 300 or more, more preferably 700 or more, more preferably 1000 or more, and preferably 2000 or less, and 1700 or less. Especially preferred is 1500 or less. Since the inverse wavelength mesogen compound has a molecular weight as described above, the coatability of the coating liquid used to form the optically anisotropic layer can be optimized in particular.

The aforementioned inverse wavelength mesogen compounds may be used singly or in combination of two or more kinds at any ratio.

Examples of the inverse wavelength mesogen compound include compounds which do not exhibit liquid crystallinity among the compounds represented by the formula (Ia). Preferable examples of the inverse wavelength mesogen compound include compounds which do not exhibit liquid crystallinity among the compounds represented by the formula (I). Among the particularly preferred inverse-wavelength mesogen compounds are the following compounds.

『Hua 8』

Among the above-mentioned mesogen compounds, from the viewpoint that the desired effect of the present invention can be better exhibited, "the molecule of this mesogen compound contains a compound selected from a benzothiazole ring (the following formula (10A) A ring); and a combination of a cyclohexyl ring (ring of the following formula (10B)) and a benzene ring (ring of the following formula (10C)); at least one of the groups "is preferred.

『Hua 9』

By polymerizing the mesogen compound, a polymer is obtained. The specific method of polymerization is not particularly limited and may be determined as an arbitrary method. Specifically, it can be performed by irradiating a coating liquid containing a mesogen compound with light. This method is detailed later.

The optically anisotropic layer includes a polymer in which a mesogen compound is combined with a positive C polymer and a mesogen compound. Specifically, the optically anisotropic layer contains, in addition to the polymer of the mesogen compound, an unreacted unreacted mesogen compound that is left unpolymerized. The ratio of the mesogen compound is a ratio of the curing degree A in a specific range specified in the present application.

The proportion of the mesogen compound and its polymer in the total solid content of the optically anisotropic layer is preferably 20% by weight or more, more preferably 30% by weight or more, more preferably 35% by weight or more, and 40% by weight % Or more is particularly preferred, and is preferably 60% by weight or less, more preferably 55% by weight or less, more preferably 50% by weight or less, and even more preferably 45% by weight or less. The ratio of the retardation Rth in the thickness direction of the optically anisotropic layer can be easily made close to the inverse dispersion by the ratio of the mesogen compound and its polymer to the lower limit of the foregoing range. Below the upper limit, the polymer of the mesogen compound can be uniformly dispersed in the optically anisotropic layer, and the mechanical strength of the optically anisotropic layer can be improved.

[1.3. Arbitrary ingredients]

The optically anisotropic layer may further include a polymer in which any component is combined with a positive C polymer, a mesogen compound, and a mesogen compound.

The optically anisotropic layer may include a plasticizer. In the case where the optically anisotropic layer contains a cellulose derivative as the positive C polymer, the optically anisotropic layer preferably contains a combination of a plasticizer and a cellulose derivative. Examples of the plasticizer include xylitol pentacetate, xylitol pentapropionate, arabinitol pentapropionate, triphenyl phosphate, and succinic acid. Polyesters of residues and ethylene glycol residues, and polyesters containing adipic acid residues and ethylene glycol residues. The proportion of the plasticizer is preferably 2.5% by weight or more, more preferably 10% by weight or more, and 25% by weight or less in the total 100% by weight of the positive C polymer and the plasticizer. It is preferably 20% by weight or less.

[1.4. Characteristics of optically anisotropic layer: refractive index]

The optically anisotropic layer satisfies Expression (2). nz (A)> nx (A) ≧ ny (A) Formula (2) nx (A), ny (A), and nz (A) are the main refractive indices of the optically anisotropic layer. An optically anisotropic layer having such refractive indices nx (A), ny (A), and nz (A) can be used as a positive C film. Therefore, when this optically anisotropic layer is incorporated into a circular polarizing plate and is suitable for an image display device, reflection of external light can be suppressed in the oblique direction of the display surface of the image display device, so that the light of the displayed image can be transmitted through Polarized sunglasses. Furthermore, when the image display device is a liquid crystal display device, the viewing angle can generally be extended. Therefore, when the display surface of the image display device is viewed from the oblique direction, the visibility of the image can be improved.

The refractive index nx (A) and the refractive index ny (A) of the optically anisotropic layer are preferably the same or close to each other. Specifically, the difference nx (A) -ny (A) between the refractive index nx (A) and the refractive index ny (A) is preferably 0.00000 to 0.00100, more preferably 0.00000 to 0.00050, and even more preferably 0.00000 to 0.00020. . The refractive index difference nx (A) -ny (A) falls within the aforementioned range, which simplifies the optical design in the case where an optically anisotropic layer is provided on an image display device, and when it is not necessary to be bonded with another retardation film Adjustment of the fit direction.

[1.5. Characteristics of optically anisotropic layer: degree of curing]

The optically anisotropic layer of the present invention satisfies Expression (3). 0.073 <A _{C - H} / A _{C = O} (liquid crystal compound) <0.125 Formula (3) In formula (3), A _{C - H} is in the infrared absorption spectrum of the optically anisotropic layer. Infrared absorption related to out-of-plane bending vibration of the C-H bond of the acrylate structure, A _{C = O} (liquid crystal compound) is in the infrared absorption spectrum of the optically anisotropic layer. The sum of infrared absorption related to the stretching vibration of the C = O bond of the structure "and" the infrared absorption related to the stretching vibration of the C = O bond of the C = O bond derived from the acrylate structure of the liquid crystal original compound " . In the present application, a value A represented by A = A _{C - H} / A _{C = O} (liquid crystal compound) may be referred to as a degree of curing A of the liquid crystal compound.

The degree of curing A is a value determined according to the "amount of unreacted enoate structure contained in the optically anisotropic layer". When the polymerization reaction is insufficient, the degree of curing A takes a larger value. When the polymerization reaction has progressed to a high degree, the curing degree A has a small value. The curing degree A is preferably greater than 0.073, more preferably greater than 0.076, and most preferably greater than 0.079. In addition, it is preferably less than 0.125, more preferably less than 0.122, and most preferably less than 0.119. When the degree of curing A in the optically anisotropic layer is equal to or greater than the aforementioned lower limit value, a good hue of the optically anisotropic layer can be achieved. On the other hand, when the degree of curing A in the optically anisotropic layer is equal to or less than the aforementioned upper limit value, high durability of the optically anisotropic layer can be achieved.

The infrared absorption spectrum of the optically anisotropic layer can be measured, for example, by a total reflection measurement method (ATR method).

As a measuring device, "Nicolet iS 5N" manufactured by Thermo Fisher Scientific Co., Ltd. may be used. The infrared absorption spectrum can be obtained as a graph showing the relationship between the wave number and the absorbance.

When the acrylate of the mesogen compound is polymerized, the vinyl group of the acrylate structure is converted to ethylenic group, and the carbonyl group bonded to the vinyl group becomes the carbonyl group bonded to the ethylidene group. The so-called "C = O bond derived from the C = O bond of the acrylate structure of the mesogen compound" means the C = O bond of the carbonyl group which is bonded to "the ethyl group appearing as a result of the polymerization of the acrylate" Knot. For the sake of convenience, the "C-H bond in the acrylate structure of the mesogen compound" is sometimes abbreviated as C-H _M and the "C = O bond in the acrylate structure of the mesogen compound""Abbreviation is C = _OM , and" C = O bond derived from a C = O bond derived from an acrylate structure of a mesogen compound "is abbreviated as C = O _MD .

In the case where the peak related to the stretching vibration of C = O _M and the peak related to the stretching vibration of C = O _{MD are} not separated but have a single peak, the infrared absorption of this single peak can also be regarded as “C = O _M stretching The sum of vibration-related infrared absorption "and" C = O _MD stretch-related vibration-related infrared absorption ".

As the value of A _{C - H} / A _{C = O} (liquid crystal compound), it is possible to use "C-H _M , the area of peaks related to out-of-plane bending vibration (area _{C - H} )" divided by "C = O _M The sum of the area of the peaks related to the stretching vibration and the area of the peaks related to the stretching vibration of C = O _MD (area _{C = O} ) "(area _{C - H} / area _{C = O} ).

In the infrared absorption spectrum, the peaks related to the out-of-plane bending vibration of C-H _M usually appear near 810 cm ^{− 1} . Moreover, the peaks related to the stretching vibration of C = O _M and the peaks related to the stretching vibration of C = O _MD usually appear around 1720 cm ^{− 1} .

When the composition of the optically anisotropic layer has a C = O bond similar to this in addition to C = O _MD , there is a case where these cannot be distinguished in the infrared absorption spectrum. In this case, it is necessary to make a plurality of optically anisotropic layers having different proportions of the components, and grasp the degree of the influence of the proportion of each component on the infrared absorption, and perform a quantification to exclude the similar C = O bonding effect. .

A case where the positive C polymer has a C = O bond similar to C = O _{MD will} be described as a specific example of this quantification.

In this example, if the infrared absorption spectrum of the optically anisotropic layer is measured, the infrared absorption A _{C = O} related to the stretching vibration of the C = O bond in this spectrum can be obtained as the sum of the following. A _{C = O} (Polymer): infrared absorption related to the stretching vibration of the C = O bond of the positive C polymer. A _{C = O} (liquid crystal compound): "Infrared absorption related to stretching vibration of unreacted C = O _M " and "C = O bond (ie, C = O _MD ) expansion and contraction of polymer of mesogen compound" Vibration-related infrared absorption ".

That is, the following formula (A1) holds. A _{C = O} = A _{C = O} (polymer) + A _{C = O} (liquid crystal compound) Formula (A1)

Consider that the value of A _{C = O} (polymer) and the value of A _{C = O} (liquid crystal compound) are proportional to "these weight ratios in the optically anisotropic layer". Therefore, the following formula (A2) holds for the infrared absorption related to the proportion of each component in the optically anisotropic layer and the stretching vibration of the C = O bond. A _{C = O} = W (polymer) x a _{C = O} (polymer) + W (liquid crystal compound) x a _{C = O} (liquid crystal compound) (A2)

In the formula: W (polymer) is the weight ratio of the "positive C polymer" to the "total weight of the positive C polymer and the weight of the mesogen and its polymer" in the optically anisotropic layer. . W (liquid crystal compound) is the weight ratio of the "liquid crystal compound and its polymer" to the "total weight of the positive C polymer and the weight of the meli crystal compound and its polymer" in the optically anisotropic layer. . That is, W (polymer) + W (liquid crystal compound) = 1. a _{C = O} (polymer) is a coefficient and is infrared absorption related to the stretching vibration of the C = O bond per unit weight ratio of the positive C polymer. a _{C = O} (the original liquid crystal compound) is a coefficient, and is a ratio of per unit weight of the original liquid crystal compound and its polymer. "Infrared absorption related to the stretching vibration of the C = O bond possessed by the acrylate structure and derived from acrylic acid. The sum of infrared absorption related to the stretching vibration of C = O bond of C = O bond of the ester structure. "

The _{values of} a _{C = O} (polymer) and a _{C = O} (liquid crystal compound) can be obtained by "the ratio of the weight of the positive C polymer to the weight of the mesogen compound and its polymer is much different The optical anisotropic layer was measured by measuring the infrared absorption spectrum. Specifically, for a plurality of optically anisotropic layers in which W (polymer) and W (liquid crystal compound) are different, A _{C = O} is measured. As a result, in many examples, the values of W (polymer), W (liquid crystal compound), and A _{C = O} are known. From these values and formula (A2), a _{C = O} (polymer) and a _{C = O} (liquid crystal) "to minimize the difference between the actual value and the theoretical value of A _{C = O} " are calculated by the least square method. Original compound). From the calculated a _{C = O} (the mesogen) and the known W (a mesogen), A _{C = O} (the mesogen) can be obtained.

The value of the degree of curing A can be controlled by adjusting the irradiation intensity and time of the active energy rays to be irradiated during the manufacturing process of the optically anisotropic layer.

[1.6. Characteristics of Optical Anisotropic Layer: Other]

The optically anisotropic layer usually satisfies Expressions (4) and (5). 0.50 <Rth (A450) / Rth (A550) <1.00 Formula (4) 1.00 ≦ Rth (A650) / Rth (A550) <1.25 Formula (5) where Rth (A450) is the aforementioned optically anisotropic layer at a wavelength of 450 The retardation in the thickness direction of nm, Rth (A550) is the retardation in the thickness direction of the optically anisotropic layer at a wavelength of 550 nm, and the retardation in the thickness direction of the aforementioned optical anisotropic layer is 650 nm.

If the foregoing formula (4) is described in detail, Rth (A450) / Rth (A550) is usually greater than 0.50, preferably greater than 0.60, more preferably greater than 0.65, and usually less than 1.00, and preferably less than 0.90. It is preferably less than 0.85.

Furthermore, if the above formula (5) is described in detail, Rth (A650) / Rth (A550) is usually 1.00 or more, preferably 1.01 or more, more preferably 1.02 or more, and usually less than 1.25 and less than 1.15 is better, and less than 1.10 is better.

An optically anisotropic layer having retardation Rth (A450), Rth (A550), and Rth (A650) in the thickness direction that satisfies the foregoing formulae (4) and (5), the retardation Rth in the thickness direction exhibits inverse wavelength dispersion. Such an optically anisotropic layer having a retardation Rth in the thickness direction exhibiting inverse wavelength dispersion is applicable to an image display device by incorporating a circular polarizer, and can be used in a wide range of tilt directions of a display surface of the image display device. The wavelength range has the function of "suppressing the reflection of external light and allowing the light of the displayed image to penetrate polarized sunglasses". Furthermore, when the image display device is a liquid crystal display device, the viewing angle can generally be effectively extended. Therefore, the visibility of the image displayed on the display surface can be effectively improved.

The optically anisotropic layer preferably satisfies Equation (6). Re (A590) ≦ 10 nm Formula (6) wherein the Re (A590) optically anisotropic layer has an in-plane retardation at a wavelength of 590 nm.

If the formula (6) is described in detail, Re (A590) is preferably 0 nm to 10 nm, more preferably 0 nm to 5 nm, and even more preferably 0 nm to 2 nm. When Re (A590) falls within the aforementioned range, the optical design in the case where the optically anisotropic layer is provided on the image display device can be simplified, and adjustment of the bonding direction when bonding with other retardation films can be eliminated.

The optically anisotropic layer preferably satisfies Equation (7). －200 nm ≦ Rth (A590) ≦ −10 nm Equation (7) where Rth (A590) is a retardation of the optically anisotropic layer in a thickness direction of a wavelength of 590 nm.

If the above formula (7) is described in detail, Rth (A590) is preferably -200 nm or more, more preferably -130 nm or more, more preferably -100 nm or more, and even more preferably -10 nm or less. -30 nm or less is preferred, and -50 nm or less is particularly preferred. When an optically anisotropic layer having such Rth (A590) is incorporated in a circular polarizer and is suitable for an image display device, it can suppress the reflection of external light in the oblique direction of the display surface of the image display device and reduce The color tone of the reflected light changes, so that the light of the displayed image can penetrate the polarized sunglasses. Furthermore, when the image display device is a liquid crystal display device, the viewing angle can generally be extended. Therefore, when the display surface of the image display device is viewed from the oblique direction, the visibility of the image can be improved.

The total light transmittance of the optically anisotropic layer is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. The total light transmittance can be measured using a UV-visible spectrometer with a wavelength range of 400 nm to 700 nm.

The haze of the optically anisotropic layer is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, and ideally 0%. Haze must be measured in accordance with JIS K 7136: 2000 by a haze meter (for example, "Haze-gard II" manufactured by Toyo Seiki Seisakusho).

The optical anisotropy can be made smaller by changing the haze due to heating by satisfying the requirements such as its curing degree. Specifically, the ratio of the change in haze before and after heating at 85 ° C. for 500 hours (the haze value after heating / the initial haze value) can be made smaller. The haze change ratio is determined to be preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.0 or less. Changes in haze due to heating are usually changes in which the haze increases, but there are cases where the haze decreases. The lower limit of the haze change ratio is set to be 0.3 or more, 0.4 or more, or 0.5 or more.

The optically anisotropic layer must be made colorless or close to its hue by satisfying its curing degree and other requirements. Specifically, the positive type C film having reverse wavelength dispersion Rth in the prior art often has a yellow hue. On the other hand, the optically anisotropic layer of the present invention must be made to have such a low yellow hue. More specifically, the optically anisotropic layer of the present invention, in the L ^* a ^* b ^* color system, as the b ^* worth preferably 2.5 or less, 2.2 or less are preferred, more preferably 2.0 or less as . The lower limit of the b ^* value is ideally zero. b ^* It is worth observing by measuring the optical anisotropic layer with a spectrophotometer (for example, "V-550" manufactured by Japan Spectroscopy Corporation).

The thickness of the optically anisotropic layer can be appropriately adjusted in a manner to obtain a desired retardation. The specific thickness of the optically anisotropic layer is preferably 1.0 μm or more, more preferably 3.0 μm or more, and more preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less.

[1.7. Manufacturing method of optically anisotropic layer]

The optically anisotropic layer can be obtained by "containing: step (a): a step of preparing a coating liquid containing a positive C polymer, a liquid crystalline original compound, and a solvent; step (b): applying a coating liquid on a support surface to obtain The step of coating the liquid layer; and the step (c): a step of irradiating the coating liquid layer with light to cure the coating liquid layer; Hereinafter, this manufacturing method is explained as a manufacturing method of the optically anisotropic layer of this invention.

[1.7.1. Step (a): Preparation of coating liquid]

The step of preparing a coating liquid can be performed by mixing a positive C polymer, a mesogen compound, and a solvent. The "proportion of positive C polymer in the total solid content of the coating solution" and the "proportion of the mesogen compound in the total solid content of the coating solution" can be adjusted separately from the "positive C polymer in the optically anisotropic layer" The ratio of the "material ratio" and "the ratio of the mesogen compound in the optically anisotropic layer" are in the same range. In the case of carrying out the production method of the present invention, a part of the mesogen compound in the coating liquid must remain in the optically anisotropic layer while maintaining an unpolymerized and unreacted state. However, in the case where the curing degree A is within the range specified in the present application, the proportion of this unreacted mesogen is extremely small.

As the solvent, an organic solvent is usually used. Examples of the organic solvent include hydrocarbon solvents such as cyclopentane and cyclohexane; cyclopentanone, cyclohexanone, methyl ethyl ketone, acetone, methyl isobutyl ketone, and N-methyl pyrrolidine. Ketone solvents such as ketones; Acetate solvents such as butyl acetate, pentyl acetate; Halogenated hydrocarbon solvents such as chloroform, dichloromethane, dichloroethane; 1,4-dioxo, cyclopentyl methyl ether, tetrahydrofuran, tetra Ether solvents such as hydropiperan, 1,3-dioxy, 1,2-dimethoxyethane; aromatic solvents such as toluene, xylene, 1,3,5-trimethylbenzene (mesitylene); and mixtures thereof . From the viewpoint of excellent workability, the boiling point of the solvent is preferably 60 ° C to 250 ° C, and more preferably 60 ° C to 150 ° C. The solvents may be used singly or in combination of two or more at any ratio.

The amount of the solvent is preferably such that the solid content concentration of the coating liquid is adjusted to a desired range as much as possible. The solid content concentration of the coating liquid is preferably 6% by weight or more, more preferably 8% by weight or more, particularly 10% by weight or more, more preferably 20% by weight or less, and 18% by weight or less. 15% by weight or less is particularly preferred. When the solid content concentration of the coating liquid falls within the aforementioned range, an optically anisotropic layer having desired optical characteristics can be easily formed.

The coating liquid used to form the optically anisotropic layer may also include any combination of a positive C polymer, a mesogen, and a solvent. In addition, any one of the components may be used alone, or two or more of them may be used in combination at any ratio.

The coating liquid may contain a polymerization initiator as an optional component. The type of the polymerization initiator may be appropriately selected depending on the type of the polymerizable group of the polymerizable compound in the coating liquid. The polymerizable compound herein is a general term for a polymerizable compound. Among them, a photopolymerization initiator is preferred. Examples of the photopolymerization initiator include a radical polymerization initiator, an anionic polymerization initiator, and a cationic polymerization initiator. Specific examples of commercially available photopolymerization initiators include: BASF's product name: Irgacure 907, product name: Irgacure 184, product name: Irgacure 369, product name: Irgacure 651, product name: Irgacure 819, Trade name: Irgacure 907, trade name: Irgacure 379, trade name: Irgacure 379EG, trade name: Irgacure OXE02 and trade name: Irgacure OXE04; trade name made by ADEKA Corporation: ADEKA OPTOMER N1919, etc. Moreover, a polymerization initiator may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The amount of a polymerization initiator such as a photopolymerization initiator in the coating liquid can be adjusted in such a manner as to obtain a desired degree of curing A. In the coating liquid, the ratio of the polymerization initiator to 100 parts by weight of the mesogen compound is preferably 1 part by weight or more, more preferably 2 parts by weight or more, more preferably 10 parts by weight or less, and 8 parts by weight or less. Is better.

The coating liquid may contain a crosslinking agent as an arbitrary component. The type of the crosslinking agent is appropriately selected depending on the type of the polymerizable compound in the coating liquid. Examples of the crosslinking agent include a trade name: A-TMPT (trimethylolpropane triacrylate, manufactured by Shin Nakamura Chemical Industry Co., Ltd.). The cross-linking agents may be used singly or in combination of two or more kinds in any ratio.

The amount of the cross-linking agent in the coating liquid can be adjusted so that the optically anisotropic layer having desired physical properties can be obtained. In the coating liquid, the proportion of the crosslinking agent to 100 parts by weight of the mesogen is preferably 1 part by weight or more, more preferably 2 parts by weight or more, more preferably 10 parts by weight or less, and 8 parts by weight or less. Better.

The coating solution contains "metals, metal complexes, dyes, pigments, fluorescent materials, phosphorescent materials, leveling agents, thixotropic agents, gelling agents, polysaccharides, surfactants, and ultraviolet absorbers. , Infrared absorbers, antioxidants, ion-exchange resins, metal oxides such as titanium oxide "and other optional additives as optional components. The proportion of these optional additives is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the positive C polymer.

It is preferable that the coating liquid does not exhibit liquid crystallinity. By using a coating liquid that does not exhibit liquid crystallinity, the dispersion of the positive C polymer and the mesogen in the optically anisotropic layer can be optimized. In addition, by using a coating liquid having no liquid crystallinity, it is possible to suppress the occurrence of uneven alignment of the mesogen compound due to the influence of air disturbance such as dry wind.

[1.7.2. Step (b): Coating]

In the step of applying the coating liquid on the supporting surface to obtain a coating liquid layer, as the supporting surface, any surface that can support the coating liquid layer may be used. As this support surface, from the viewpoint of optimizing the surface state of the optically anisotropic layer, a flat surface without a concave portion and a convex portion is generally used. The support surface is preferably a surface using a long substrate. When a long substrate is used, the coating liquid can be continuously applied to the continuously transported substrate. Therefore, by using a long-shaped substrate, the optically anisotropic layer can be continuously manufactured, so that productivity can be improved.

As the substrate, a substrate film is usually used. As the substrate film, "the film which can be used as the substrate of an optical stack" can be appropriately selected. Among them, a transparent film is used as a base film from the viewpoint of "a multilayer film including a base film and an optically anisotropic layer can be used as an optical film, and there is no need to peel the optical anisotropic layer from the base film". Better. Specifically, the total light transmittance of the base film is preferably 80% or more, more preferably 85% or more, and even more preferably 88% or more.

The material of the base film is not particularly limited, and various resins may be used. Examples of the resin include resins containing various polymers. Examples of the polymer include an alicyclic structure-containing polymer, cellulose ester, polyvinyl alcohol, polyimide, UV penetration acrylic, polycarbonate, polyfluorene, polyetherfluorene, and epoxy polymer. , Polystyrene, and combinations thereof. Among these, from the viewpoints of transparency, low hygroscopicity, dimensional stability, and light weight, alicyclic structure-containing polymers and cellulose esters are preferable, and alicyclic structure-containing polymers are more preferable. good.

The alicyclic structure-containing polymer is a polymer having an alicyclic structure in a repeating unit, and is usually an amorphous polymer. As the alicyclic structure-containing polymer, either a polymer containing an alicyclic structure in the main chain and a polymer containing an alicyclic structure in the side chain can be used.

Examples of the alicyclic structure include a cycloalkane structure and a cycloolefin structure, but a cycloalkane structure is preferred from the viewpoint of thermal stability and the like.

The number of carbons of the repeating unit constituting an alicyclic structure is not particularly limited, but it is preferably 4 or more, more preferably 5 or more, more preferably 6 or more, and preferably 30 or less, and 20 It is preferable to use less than 15 pieces, and it is particularly preferable to use 15 pieces or less.

The proportion of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer may be appropriately selected depending on the purpose of use, but is preferably 50% by weight or more, more preferably 70% by weight or more, and 90% by weight or more. It's better. By increasing the repeating unit having an alicyclic structure as described above, the heat resistance of the base film can be improved.

Examples of the alicyclic structure-containing polymer include (1) a norbornene polymer, (2) a monocyclic cyclic olefin polymer, (3) a cyclic conjugated diene polymer, and (4) a vinyl alicyclic hydrocarbon. Polymers and these hydrides. Among these, from the viewpoint of transparency and moldability, a norbornene polymer is preferred.

Examples of the olefin-reducing polymer include ring-opening polymers of olefin-reducing monomers, ring-opening copolymers of olefin-reducing monomers and other monomers capable of ring-opening copolymerization, and hydrides thereof; Addition polymers of olefin monomers, addition copolymers of olefin-lowering monomers and other monomers capable of copolymerization, etc. Among these, in view of transparency, a hydride of a ring-opening polymer of a norbornene monomer is particularly preferred.

The alicyclic structure-containing polymer can be selected from known polymers such as those disclosed in Japanese Patent Laid-Open No. 2002-321302.

When a resin containing an alicyclic structure-containing polymer is used as the material of the base film, the thickness of the base film is 1 μm in terms of making it easier to “improve productivity, reduce thickness, and reduce weight”. It is preferably from 1000 μm, more preferably from 5 μm to 300 μm, and even more preferably from 30 μm to 100 μm.

The resin containing an alicyclic structure-containing polymer may be made of only an alicyclic structure-containing polymer, and as long as the effect of the present invention is not significantly impaired, any admixture may be contained. The proportion of the alicyclic structure-containing polymer in the resin containing the alicyclic structure-containing polymer is preferably 70% by weight or more, and more preferably 80% by weight or more.

Examples of suitable specific examples of the resin containing the "alicyclic structure-containing polymer" include "ZEONOR 1420" and "ZEONOR 1420R" manufactured by Japan's Rui On.

Examples of the coating method of the coating liquid include a curtain coating method, an extrusion coating method, a roll coating method, a spin coating method, a dip coating method, a bar coating method, a spray coating method, a slant plate coating method, a printing coating method, and a gravure plate. Coating method, die coating method, gap coating method and dipping method. The thickness of the applied coating liquid may be appropriately set depending on the desired thickness of the required optically anisotropic layer.

[1.7.3. Drying]

After the step (b) and before the step (c), a step of drying the coating liquid layer may be performed as required. By drying, the solvent can be removed from the coating liquid layer, and the state of the solid component of the coating liquid can be stabilized. As a result, the step (c) can be performed in a state where the solid content of the coating liquid is stable. As a specific method of drying, any method such as heat drying, reduced pressure drying, heat reduced pressure drying, or natural drying may be adopted.

The method for producing an optically anisotropic layer of the present invention can produce an optically anisotropic layer by a simple operation called "coating and curing a coating liquid", which includes a combination of a positive C polymer and a mesogen compound. Therefore, an alignment film as described in Patent Document 1 is not required. Therefore, the operation of "the adjustment of the compatibility of the inverse wavelength dispersive liquid crystal with the alignment film and the formation of the alignment film" is not required, so that the optically anisotropic layer can be easily manufactured.

Furthermore, a coating liquid containing a combination of a positive C polymer and a mesogen compound can suppress the occurrence of uneven alignment of the mesogen compound due to the influence of air disturbance during drying. Therefore, an optically anisotropic layer having a uniform alignment state can be easily obtained in a wide range of in-plane directions, and an optically anisotropic layer having an excellent plane state can be easily obtained. Therefore, it is possible to suppress white turbidity caused by uneven alignment of the optically anisotropic layer.

[1.7.4. Process (c): Light irradiation]

Through the process of light irradiation, a part of the acrylate structure of the mesogen compound is polymerized to become a polymer of the mesogen compound. Through this polymerization, an optically anisotropic layer containing a polymer of a positive C polymer and a mesogen compound is formed. For irradiation of the coating liquid layer with light, a method suitable for "property properties of components contained in the coating liquid such as a polymerizable compound and a polymerization initiator" can be appropriately selected. The light irradiated may include visible light, ultraviolet light, and infrared light. Among them, a method of irradiating ultraviolet rays is preferable in terms of simple operation.

The ultraviolet irradiation intensity is preferably in a range of 0.1 mW / cm ² to 1000 mW / cm ² , and more preferably in a range of 0.5 mW / cm ² to 600 mW / cm ² . The ultraviolet irradiation time is preferably in the range of 1 second to 300 seconds, and more preferably in the range of 3 seconds to 100 seconds. The integrated ultraviolet light quantity (mJ / cm ² ) can be obtained from the ultraviolet irradiation intensity (mW / cm ² ) × irradiation time (second). A preferable integrated light amount is 600 mJ / cm ² to 5000 mJ / cm ² . As the ultraviolet light source, a high-pressure mercury lamp, a metal halide lamp, or a low-pressure mercury lamp can be used. The step (c) is preferably carried out in an inert gas environment such as a nitrogen environment and tends to reduce the proportion of residual monomers.

The manufacturing method of an optically anisotropic layer may include arbitrary processes other than the said process. For example, the method may include a step of peeling the optically anisotropic layer from the substrate.

[2. Multilayer for transfer]

The multilayer material for transfer of the present invention includes a substrate and the optically anisotropic layer. Here, the so-called multilayer material for transfer is a member including a plurality of layers, and a part of the plurality of layers is transferred and a part of the layer is provided for the manufacture of a product including the layers. In the transfer multilayer of the present invention, the optically anisotropic layer is supplied for the production of the aforementioned product.

As a base material, the same thing as the base material demonstrated in the manufacturing method of an optically anisotropic layer can be used. Among them, those which can be peeled off are preferred as the substrate. The multilayer material for transfer provided with such a base material can be manufactured by performing "the manufacturing method of the said optically anisotropic layer using a base material".

The multilayer material for transfer can be used for manufacture of an optical film. For example, an optically anisotropic layer and a resin film can be manufactured by laminating | stacking a base material after bonding the optically anisotropic layer of a multilayer material for transfer, and a resin film.

[3. Optically Anisotropic Stack]

An optically anisotropic stack according to the present invention includes the optically anisotropic layer and a retardation layer.

[3.1. Optically Anisotropic Layer in Optically Anisotropic Stack]

As the optically anisotropic layer of the optically anisotropic stack, the above is used. However, it is preferable that the optically anisotropic layer in the optically anisotropic stack satisfies the following formulae (12) and (13). Re (A590) ≦ 10 nm Formula (12) −110 nm ≦ Rth (A590) ≦ −20 nm Formula (13) Re (A590) and Rth (A590) are defined as described above.

If the formula (12) is described in detail, Re (A590) is preferably 0 nm to 10 nm, more preferably 0 nm to 5 nm, and even more preferably 0 nm to 2 nm. When Re (A590) falls within the foregoing range, the optical design in the case where an optically anisotropic stack is provided in an image display device can be simplified.

Furthermore, if the above formula (13) is described in detail, Rth (A590) is preferably -110 nm or more, more preferably -100 nm or more, more preferably -20 nm or less, and more preferably -40 nm or less. It is better to be below -50 nm. An optically anisotropic stack having an optically anisotropic layer having such Rth (A590) can be used in a tilt direction of a display surface of an image display device when a circular polarizing plate is incorporated in the image display device. Effectively exerts the function of "suppressing the reflection of external light and allowing the light of the displayed image to penetrate polarized sunglasses". Therefore, when the display surface of the image display device is viewed from the oblique direction, the visibility of the image can be effectively improved.

[3.2. Phase difference layer in optically anisotropic stack]

[3.2.1. Optical characteristics of retardation layer]

The phase difference layer is a layer body satisfying the formula (8). nx (B)> ny (B) ≧ nz (B) Equation (8) where nx (B), ny (B), and nz (B) are the main refractive indices of the retardation layer. An optically anisotropic stack having such a retardation layer can be combined with a linear polarizer to produce a circularly polarizing plate. The circular polarizing plate is arranged on the display surface of the image display device, and when the display surface is viewed from the front direction, the reflection of external light is suppressed, so that the light of the displayed image can penetrate the polarized sunglasses, so the image can be improved. Visibility.

The refractive index ny (B) and the refractive index nz (B) of the retardation layer are preferably the same or close to each other. Specifically, the absolute value of the difference between the refractive index ny (B) and the refractive index nz (B) | ny (B)-nz (B) | is preferably 0.00000 to 0.00100, more preferably 0.00000 to 0.00050, and 0.00000 to 0.00020 is particularly preferred. Since the absolute value of the refractive index difference | ny (B) -nz (B) | falls within the aforementioned range, the optical design in the case where the optically anisotropic stack is provided on the image display device can be simplified.

The phase difference layer preferably satisfies Equation (11). 110 nm ≦ Re (B590) ≦ 170 nm Formula (11) where the Re (B590) retardation layer has an in-plane retardation at a wavelength of 590 nm.

If the above formula (11) is described in detail, Re (B590) is preferably 110 nm or more, more preferably 120 nm or more, more preferably 130 nm or more, more preferably 170 nm or less, and 160 nm or less Preferably, 150 nm or less is particularly preferred. An optically anisotropic stack having such a retardation layer of Re (B590) can be combined with a linear polarizer to obtain a circularly polarizing plate. By setting the circular polarizing plate on the display surface of the image display device, when the display surface is viewed from the front, the reflection of external light can be suppressed, and the light of the displayed image can pass through polarized sunglasses, so the image can be improved. Visibility.

It is preferable that the retardation layer satisfies Expressions (9) and (10). 0.75 <Re (B450) / Re (B550) <1.00 Formula (9) 1.01 <Re (B650) / Re (B550) <1.25 Formula (10) where Re (B450) is the phase retardation layer at 450 nm in wavelength. In-plane retardation, Re (B550) is an in-plane retardation of the aforementioned retardation layer at a wavelength of 550 nm, and Re (B650) is an in-plane retardation of the aforementioned retardation layer at a wavelength of 650 nm.

If the foregoing formula (9) is described in detail, Re (B450) / Re (B550) is preferably greater than 0.75, more preferably greater than 0.78, more preferably greater than 0.80, and more preferably less than 1.00, and less than 0.95 is more preferable, and less than 0.90 is more preferable.

If the foregoing formula (10) is explained in detail, Re (B650) / Re (B550) is preferably greater than 1.01, more preferably greater than 1.02, more preferably greater than 1.04, and most preferably less than 1.25, and less than 1.22 is preferred, and less than 1.19 is particularly preferred.

A retardation layer having in-plane retardations Re (B450), Re (B550), and Re (B650) satisfying the aforementioned formulas (9) and (10), and the in-plane retardation Re exhibits inverse wavelength dispersion. An optically anisotropic stack having such an in-plane retardation retardation layer exhibiting a reverse wavelength dispersion retardation layer can be applied to an image display device by incorporating a circular polarizer, and can be used in the front direction of the display surface of the image display device. In addition, it has the function of "suppressing the reflection of external light and allowing the light of the displayed image to penetrate polarized sunglasses" in a wide wavelength range. Therefore, the visibility of the image displayed on the display surface can be effectively improved.

The direction of the slow axis in the plane of the retardation layer is arbitrary, and can be arbitrarily set depending on the application of the optically anisotropic stack. In the case where the optically anisotropic stack is a long thin film, the angle between the slow axis of the retardation layer and the width direction of the film is preferably more than 0 ° and less than 90 °. And in a certain aspect, the angle between the slow axis in the plane of the retardation layer and the width direction of the film can be determined as so-called 15 ° ± 5 °, 22.5 ° ± 5 °, 45 ° ± 5 °, or 75 ° ± 5 ° is preferred, 15 ° ± 4 °, 22.5 ° ± 4 °, 45 ° ± 4 ° or 75 ° ± 4 ° is preferred, 15 ° ± 3 °, 22.5 ° ± 3 °, 45 ° ± 3 ° or 75 ° ± 3 ° is a more preferable specific range. By having such an angular relationship, it becomes possible to "adhere the optically anisotropic stack to a long linear polarizer with a roll-to-roll, and efficiently manufacture a circular polarizer".

The total light transmittance of the retardation layer is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. The haze of the retardation layer is preferably 5% or less, more preferably 3% or less, even more preferably 1% or less, and ideally 0%.

[3.2.2. Stretched film layer as a retardation layer]

As the retardation layer as described above, an extended film layer may be used. In the case where the stretched film layer is used as the retardation layer, the stretched film layer may include a resin that is a material of the base film described in the method for producing an optically anisotropic layer. A thin film layer containing such a resin must exhibit an optical property such as retardation by performing a stretching treatment. Among them, the stretched film layer preferably contains an alicyclic structure-containing polymer.

The extending direction of the stretched film layer is arbitrary. Therefore, the extending direction may be a long side direction, a width direction, or an oblique direction. Furthermore, among these extending directions, extending may be performed in two or more directions. Here, the oblique direction refers to a direction in which the film is in-plane and is not parallel to the long-side direction and the width direction.

Among them, the stretched film layer is preferably an obliquely stretched film layer. That is, the "stretched film layer" is preferably "a film that is a long film and extends in a direction that is not parallel to the long direction and width direction of the film". In the case of an obliquely extending film layer, the angle between the film width direction and the extension direction is specifically set to be more than 0 ° and less than 90 °. By using such an obliquely stretched film layer as a retardation layer, it becomes possible to "adhere an optically anisotropic stack to a long linear polarizer with a roll-to-roll and efficiently manufacture a circular polarizer".

The angle between the extension direction and the film width direction can be determined as 15 ° ± 5 °, 22.5 ° ± 5 °, 45 ° ± 5 ° or 75 ° ± 5 °, and 15 ° ± 4 °, 22.5 ° ± 4 °, 45 ° ± 4 °, or 75 ° ± 4 ° is preferred, and 15 ° ± 3 °, 22.5 ° ± 3 °, 45 ° ± 3 °, or 75 ° ± 3 ° are more preferred. range. By having such an angular relationship, the optically anisotropic stack can be made into a material capable of efficiently manufacturing a circularly polarizing plate.

The stretched film layer preferably has a multilayer structure including a plurality of layers. The stretched film layer having a multilayer structure can exert various characteristics by combining the functions of each layer included in the stretched film layer. For example, the stretched film layer includes, in order: "a first outer layer made of a resin containing a polymer, an intermediate layer made of a resin containing a polymer and an ultraviolet absorber, and a resin made of a polymer The resulting second outer layer is preferred. At this time, the polymers contained in each layer may be different, but the same is preferable. Such an extended film layer having a first outer layer, a middle layer, and a second outer layer can suppress the penetration of ultraviolet rays. In addition, since the first outer layer and the second outer layer are provided on both sides of the intermediate layer, it is possible to suppress the bleeding of the ultraviolet absorber.

The amount of the ultraviolet absorber in the resin contained in the intermediate layer is preferably 3% by weight or more, more preferably 4% by weight or more, particularly preferably 5% by weight or more, and preferably 20% by weight or less. It is preferably 18% by weight or less, and particularly preferably 16% by weight or less. When the amount of the ultraviolet absorbent is above the lower limit of the foregoing range, the ability to prevent the penetration of the stretched film layer from ultraviolet rays can be particularly improved, and by being below the upper limit of the foregoing range, the relative effectiveness of the stretched film layer can be improved. Visibility of visible light.

The thickness of the intermediate layer is preferably set such that "the ratio represented by" the thickness of the intermediate layer "/" the entire thickness of the stretched film layer "falls within a specific range". The aforementioned specific range is preferably ½ or more, more preferably 1/4 or more, more preferably 1/3 or more, and more preferably 80/82 or less, more preferably 79/82 or less, and 78 / Below 82 is particularly preferred. When the aforementioned ratio is above the lower limit of the aforementioned range, the ability of the stretched film layer to prevent ultraviolet rays from penetrating can be improved in particular, and by being below the upper limit of the aforementioned range, the thickness of the stretched film layer can be thinned.

The thickness of the stretched film layer of the retardation layer is preferably 10 μm or more, more preferably 13 μm or more, particularly 15 μm or more, more preferably 60 μm or less, and 58 μm or less. It is particularly preferred that it is 55 μm or less. A desired retardation can be exhibited when the thickness of the stretched film layer is greater than or equal to the lower limit of the aforementioned range, and a thin film can be achieved by being equal to or less than the upper limit of the aforementioned range.

The stretched thin film layer can be produced, for example, by a method including a step of preparing the thin film layer before stretching and a step of stretching the prepared thin film layer.

The pre-stretched film layer can be produced, for example, by "molding a resin made of a material of the stretched film layer by an appropriate molding method". Examples of the forming method include a casting method, an extrusion method, and an inflation method. Among them, the melt extrusion method without using a solvent can effectively reduce the amount of residual volatile components, and it is preferable from the viewpoint of global environment and working environment and the viewpoint of excellent manufacturing efficiency. Examples of the melt extrusion method include a gas-filling method using a mold, and a method using a T mold is preferred from the viewpoint of excellent productivity and thickness accuracy.

In the case of manufacturing a stretched film layer having a multilayer structure, a person having a multilayer structure is usually prepared as the stretched film layer. The pre-stretched film layer having a multilayer structure as described above can be produced by, for example, a molding method such as a co-extrusion method and a co-casting method, by molding a resin corresponding to each layer included in the multilayer structure. Among these molding methods, the coextrusion method is excellent because it has excellent manufacturing efficiency and it is difficult to leave volatile components in the film. Examples of the coextrusion method include a coextrusion T-die method, a coextrusion inflation method, and a coextrusion lamination method. Among them, the co-extrusion T die method is preferred. For the co-extrusion T-die method, there are feed block method and multi-manifold method, which can reduce the uneven thickness, especially the multi-manifold method.

By forming the resin as described above, a long stretched stretched film can be obtained. By stretching this stretched front film, a stretched film layer can be obtained. Stretching is usually carried out continuously while the pre-stretched film is transported along the long side. At this time, the extending direction may be the long side direction or the width direction of the film, but the oblique direction is preferred. Further, the extension may be a free uniaxial extension in which no restraining force is applied in the direction other than the extension direction, or an extension in which restraint force is applied in the direction other than the extension direction. Such stretching may be performed using any stretcher such as a roll stretcher or a tenter stretcher.

The stretching ratio is preferably 1.1 times or more, more preferably 1.15 times or more, even more preferably 1.2 times or more, and even more preferably 3.0 times or less, more preferably 2.8 times or less, and even more preferably 2.6 times or less. By setting the stretching magnification to be greater than the lower limit of the aforementioned range, the refractive index in the stretching direction can be enlarged. In addition, by setting it below the upper limit value, the slow axis direction of the stretched film layer can be easily controlled.

The elongation temperature is preferably Tg-5 ° C or higher, Tg-2 ° C or higher, Tg ° C or higher, Tg + 40 ° C or lower, Tg + 35 ° C or lower, Tg + 30 ° C or lower It's better. "Tg" here means the highest temperature among the glass transition temperatures of the polymer contained in the film layer before stretching. By setting the stretching temperature in the aforementioned range, the molecules contained in the thin film layer before stretching can be surely aligned, and thus it is easy to obtain an extended film layer that can function as a retardation layer having desired optical characteristics.

[3.2.3. Liquid crystal layer as a retardation layer]

As the retardation layer as described above, a liquid crystal layer containing a liquid crystal compound (hereinafter referred to as a "liquid crystal compound for retardation layer") which can also be fixed in an aligned state may be used. At this time, as the liquid crystal compound for the retardation layer, it is preferable to use the aforementioned reverse wavelength dispersion liquid crystal compound which has been uniformly aligned. Thereby, even in the retardation layer, the same advantages as those described in the item of the optically anisotropic layer can be obtained. Among them, the liquid crystal layer as the retardation layer is particularly preferably "a liquid crystal compound represented by the following formula (II) including an alignment state that can also be fixed".

『Hua 10』

In the aforementioned formula (II), Y ¹ to Y ⁸ , G ¹ , G ² , Z ¹ , Z ² , A ^x , A ^y , A ¹ to A ⁵ , Q ¹ , m, and n represent the same as in the formula (I ) Meaning in the same meaning. Therefore, the liquid crystal compound represented by the formula (II) means the same compound as the liquid crystal compound represented by the formula (I). Among them, in the formula (I), one or both of Z ¹ -Y ⁷ -and -Y ⁸ -Z ² are propylene fluorenyloxy; on the other hand, in the formula (II), these two Alternatively, it may be a group other than acryloxy.

The thickness of the liquid crystal layer as the retardation layer is not particularly limited, and it can be adjusted appropriately so that characteristics such as retardation can reach a desired range. The specific thickness of the liquid crystal layer is preferably 0.5 μm or more, more preferably 1.0 μm or more, and more preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less.

The liquid crystal layer as the retardation layer can be produced, for example, by a method including a step of preparing a liquid crystal composition including a liquid crystal compound for the retardation layer; applying the liquid crystal composition to a support to obtain a liquid crystal composition. The step of aligning the phase difference layer included in the layer of the liquid crystal composition with a liquid crystal compound;

In the step of preparing a liquid crystal composition, a liquid crystal compound for a retardation layer and an optional component used as required are usually mixed to obtain a liquid crystal composition.

The liquid crystal composition may contain a polymerizable monomer as an optional component. The "polymerizable monomer" refers to a compound other than the liquid crystal compound for a retardation layer among compounds having polymerization ability and operating as a monomer. As the polymerizable monomer, for example, one having one or more polymerizable groups per molecule can be used. In the case of a crosslinkable monomer having two or more polymerizable groups per polymerizable monomer, crosslinkable polymerization can be achieved. Examples of this polymerizable group include the same groups as "the groups Z ¹ -Y ⁷ -and Z ² -Y ⁸ -or a part thereof in the compound (I)", and more specifically, for example, propylene Fluorenyl, methacryl, and epoxy. The polymerizable monomers may be used singly or in combination of two or more at any ratio.

In the liquid crystal composition, the proportion of the polymerizable monomer is preferably 1 to 100 parts by weight, and more preferably 5 to 50 parts by weight based on 100 parts by weight of the liquid crystal compound for the retardation layer.

The liquid crystal composition may include a photopolymerization initiator as an optional component. Examples of the polymerization initiator include the same polymerization initiators included in the coating liquid used to produce the optically anisotropic layer. Moreover, a polymerization initiator may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

In the liquid crystal composition, the proportion of the polymerization initiator is preferably 0.1 to 30 parts by weight, and more preferably 0.5 to 10 parts by weight based on 100 parts by weight of the polymerizable compound.

The liquid crystal composition may include a surfactant as an optional component. As the surfactant, a nonionic surfactant is preferred. As the nonionic surfactant, a commercially available product may be used. For example, a nonionic surfactant which is an oligomer having a molecular weight of several thousands can be used. As specific examples of these surfactants, "PF-151N", "PF-636", "PF-6320", "PF-656", "PF-6520", "PF" -3320 "," PF-651 "," PF-652 "; NEOS FTERGENT" FTX-209F "," FTX-208G "," FTX-204D "," 601AD "; Tsingmei Chemical Company Surflon's" KH- 40 "," S-420 ", etc. The surfactant may be used singly or in combination of two or more at any ratio.

In the liquid crystal composition, the proportion of the surfactant is preferably 0.01 to 10 parts by weight, and more preferably 0.1 to 2 parts by weight based on 100 parts by weight of the polymerizable compound.

The liquid crystal composition may include a solvent as an optional component. Examples of the solvent include the same solvents as those contained in a coating liquid for producing an optically anisotropic layer. The solvents may be used singly or in combination of two or more at any ratio.

The proportion of the solvent in the liquid crystal composition is preferably 100 parts by weight to 1,000 parts by weight based on 100 parts by weight of the polymerizable compound.

Furthermore, the liquid crystal composition may include "metals, metal complexes, dyes, pigments, fluorescent materials, phosphorescent materials, leveling agents, thixotropic agents, gelling agents, polysaccharides, ultraviolet absorbers, and infrared absorbers. , Antioxidants, ion-exchange resins, metal oxides such as titanium oxide "and other additives as optional components. The proportion of this additive is preferably 0.1 to 20 parts by weight per 100 parts by weight of the polymerizable compound.

After preparing the liquid crystal composition as described above, a step of applying the liquid crystal composition on a support to obtain a layered body of the liquid crystal composition is performed. As the support, it is preferable to use a long support. When a long-shaped support is used, a liquid crystal composition can be continuously applied to a support that is continuously transported. Therefore, by using a long-shaped support, a liquid crystal layer as a retardation layer can be continuously manufactured, so that productivity can be improved.

When the liquid crystal composition is applied to the support, it is preferable to apply a moderate tension (usually 100 N / m to 500 N / m) to the support and reduce the transport vibration of the support while maintaining flatness. State of coating. The so-called flatness refers to the amount of vibration that is perpendicular to the width direction of the support and the up-down direction of the conveyance direction. Ideally, it is 0 mm, usually 1 mm or less.

As the support, a support film is usually used. As the support film, "the film used as the support of the optical stack" can be appropriately selected. Among them, from the standpoint that "an optically anisotropic stack including a support film, a retardation layer, and an optically anisotropic layer can be used as an optical film without peeling of the support film", as the support film, A transparent film is preferred. Specifically, the total light transmittance of the support film is preferably 80% or more, more preferably 85% or more, and even more preferably 88% or more.

The material of the support film is not particularly limited, and various resins must be used. Examples of the resin include a resin including "a polymer described as a material for use as a base material for forming an optically anisotropic layer". Among these, from the viewpoints of transparency, low hygroscopicity, dimensional stability, and light weight, as the polymer including the resin, an alicyclic structure-containing polymer and a cellulose ester are preferred, and An alicyclic structure polymer is preferred.

As the support, an anchoring force must be used. The term “orientation limiting force of a support” refers to a property of the support “to align the liquid crystal compound for the retardation layer in the liquid crystal composition applied to the support”.

The alignment restricting force can be imparted by "applying an alignment restricting force to a member such as a film made of a material of a support". Examples of this treatment include stretching treatment and rubbing treatment.

In a preferred aspect, the support system extends the film. By making this stretched film, a support having an alignment restricting force corresponding to the extending direction can be obtained.

The stretching direction of the stretched film is arbitrary. Therefore, the extending direction may be a long side direction, a width direction, or an oblique direction. Furthermore, among these extending directions, extending may be performed in two or more directions. The extension magnification can be appropriately set in a "range where an alignment limiting force is generated on the surface of the support". In the case where the material of the support is a resin having a positive intrinsic birefringence value, the molecules are aligned in the extension direction and exhibit a slow axis in the extension direction. For the stretching, a known stretching machine such as a tenter stretching machine is used.

In a better aspect, the support system extends the film obliquely. In the case where the supporting system extends the film obliquely, the angle between the extending direction and the width direction of the extending film is specifically set to be more than 0 ° and less than 90 °. By using such an obliquely stretched film as a support, an optically anisotropic stack can be made into a material capable of efficiently manufacturing a circularly polarizing plate.

And, in a certain aspect, the angle between the stretching direction and the width direction of the stretched film may be determined as so-called 15 ° ± 5 °, 22.5 ° ± 5 °, 45 ° ± 5 °, or 75 ° ± 5 ° Preferably, 15 ° ± 4 °, 22.5 ° ± 4 °, 45 ° ± 4 ° or 75 ° ± 4 ° is preferred, 15 ° ± 3 °, 22.5 ° ± 3 °, 45 ° ± 3 ° or 75 ° ± 3 ° is a more preferable specific range. By having such an angular relationship, the optically anisotropic stack can be made into a material capable of efficiently manufacturing a circularly polarizing plate.

Examples of the coating method of the liquid crystal composition include a curtain coating method, an extrusion coating method, a roll coating method, a spin coating method, a dip coating method, a bar coating method, a spray coating method, a slant plate coating method, a printing coating method, Gravure coating method, die coating method, gap coating method and dipping method. The thickness of the layer of the applied liquid crystal composition can be appropriately set depending on the desired thickness of the liquid crystal layer as the retardation layer.

After the liquid crystal composition is coated on the support to obtain a layered body of the liquid crystal composition, a step of orienting the retardation layer included in the layered body of the liquid crystal composition with a liquid crystal compound is performed. Thereby, the liquid crystal compound for the retardation layer included in the layer body of the liquid crystal composition is aligned with the alignment direction corresponding to the alignment restricting force of the support. For example, when a stretched film is used as a support, the phase difference layer included in the layered body of the liquid crystal composition is aligned with a liquid crystal compound in parallel with the stretched direction of the stretched film.

The alignment of the liquid crystal compound for the retardation layer may be achieved directly by coating, but may also be achieved by applying an alignment treatment such as heating after coating, if necessary. The conditions for the alignment treatment may be appropriately set depending on the properties of the liquid crystal composition to be used, and for example, the conditions for processing for 30 seconds to 5 minutes at a temperature of 50 ° C to 160 ° C may be determined.

By aligning the liquid crystal compound for the retardation layer in the layered body of the liquid crystal composition as described above, desired optical characteristics are exhibited in the layered body of the liquid crystal composition, so that a liquid crystal layer that can function as a retardation layer can be obtained. .

As a method for manufacturing the liquid crystal layer of the retardation layer, an arbitrary step may be further included. The manufacturing method of a liquid crystal layer can also perform the process of drying the layer body of a liquid crystal composition, or a liquid crystal layer, for example. This drying is achieved by drying methods such as natural drying, heating drying, reduced pressure drying, and reduced pressure heating drying.

In addition, as a method for manufacturing the liquid crystal layer of the retardation layer, for example, after the liquid crystal compound for the retardation layer included in the liquid crystal composition is aligned, a step of fixing the alignment state of the liquid crystal compound for the retardation layer may be performed. In this step, the alignment state of the liquid crystal compound for the retardation layer is usually fixed by polymerizing the liquid crystal compound for the retardation layer. In addition, by polymerizing the liquid crystal compound for the retardation layer, the rigidity of the liquid crystal layer can be increased, and the mechanical strength can be improved.

The liquid crystal compound for the retardation layer is polymerized to obtain a method for appropriately selecting properties of components of the liquid crystal composition. For example, a method of irradiating light is preferred. Among them, a method of irradiating ultraviolet rays is preferable in terms of simple operation. Irradiation conditions such as ultraviolet irradiation intensity, ultraviolet irradiation time, integrated ultraviolet light amount, and ultraviolet irradiation light source can be adjusted to the same range as the irradiation conditions in the method for producing an optically anisotropic layer.

During the polymerization, the liquid crystal compound for the retardation layer is usually polymerized while maintaining the molecular alignment. Therefore, by the aforementioned polymerization, a liquid crystal layer including a polymer of an aligned liquid crystal compound for a retardation layer can be obtained, and the aligned liquid crystal compound for the retardation layer follows a phase included in the liquid crystal composition before polymerization. The difference layer is aligned in a direction parallel to the alignment direction of the liquid crystal compound. Therefore, in the case of using a stretched film as a support, for example, a liquid crystal layer having an alignment direction parallel to the stretching direction of the stretched film can be obtained. The term "parallel" herein means that the deviation between the extension direction of the stretched film and the alignment direction of the polymer of the liquid crystal compound for the retardation layer is usually ± 3 °, preferably ± 1 °, and ideally 0 °.

In the liquid crystal layer as the retardation layer manufactured by the above manufacturing method, the molecules of the polymer obtained from the liquid crystal compound for the retardation layer preferably have the alignment regularity for the horizontal alignment of the support film. For example, in a case where an alignment restricting force is used as the support film, the molecular level alignment of the polymer of the liquid crystal compound for the retardation layer in the liquid crystal layer can be performed. Herein, the molecules of the polymer of the liquid crystal compound for the retardation layer with respect to the support film "horizontal alignment" refer to the "original liquid crystal skeleton" which is derived from the structural unit derived from the liquid crystal compound for the retardation layer contained in the polymer. The average direction of the long-axis direction is parallel or nearly parallel to the film surface "(for example, the angle between the film surface and the film surface is within 5 °). As in the case of using the compound represented by the formula (II) as the liquid crystal compound for the retardation layer, there are cases in which a plurality of liquid crystal protoskeleton with different alignment directions exist in the liquid crystal layer. The longest kind of liquid crystal protoskeleton among them The direction in which the long axis direction is aligned usually becomes the alignment direction.

The method for producing a liquid crystal layer as a retardation layer may include a step of peeling the support after obtaining the liquid crystal layer.

[3.3. Any layer in the optically anisotropic stack]

The optically anisotropic stacked body is further provided with an arbitrary layer combination of the optically anisotropic layer and the retardation layer. Examples of the arbitrary layer body include a bonding layer and a hard coat layer.

[3.4. Manufacturing method of optically anisotropic stack]

The optically anisotropic stack can be produced, for example, by the following production method 1 or 2.

． Manufacturing method 1:

It includes the steps of "manufacturing a retardation layer" and "using the aforementioned retardation layer as a base material and performing the above-mentioned method of manufacturing the optically anisotropic layer to form an optically anisotropic layer on the retardation layer, thereby obtaining Optical anisotropic stack ".

As in the case of the manufacturing method 1, when the coating liquid is coated on the retardation layer, an optically anisotropic stack can be obtained by forming an optically anisotropic layer on the retardation layer by drying the coating liquid layer.

． Manufacturing method 2:

It includes a step of "manufacturing a retardation layer", a step of "manufacturing a multilayer for transfer", and "adhering an optically anisotropic layer and a retardation layer of a multilayer for transfer and obtaining an optically anisotropic stack "And a manufacturing method of the step of" peeling off the base material of the multilayer for transfer ".

For example, in the case of the manufacturing method 2 where an optically anisotropic layer and a retardation layer are bonded to manufacture an optically anisotropic stack, a suitable bonding agent may be used for bonding. As this bonding agent, for example, the same bonding agent as that used by a user in a polarizing plate described later can be used.

In addition, the method for producing the optically anisotropic stack may include any steps in addition to the above steps. For example, the aforementioned manufacturing method may include a step of providing an arbitrary layer such as a hard coat layer.

[4. Polarizer]

A polarizing plate of the present invention includes a "linear polarizer" and "the above-mentioned optically anisotropic layer, a multilayer for transfer, or an optically anisotropic stack". Such a polarizing plate can improve the visibility of an image when the image display device is viewed from an oblique direction by being provided in the image display device.

As the linear polarizer, a known linear polarizer "used in a device such as a liquid crystal display device and other optical devices" may be used. Examples of the linear polarizer include a film obtained by "adsorbing iodine or a dichroic dye onto a polyvinyl alcohol film and then uniaxially stretching in a boric acid bath"; and a film obtained by "adsorbing iodine or a dichroic dye" A film obtained by extending and extending a polyvinyl alcohol film, and further modifying a part of the polyvinyl alcohol unit in the molecular chain to a polyvinylidene unit. In addition, as another example of the linear polarizer, a polarizer having a function of separating polarized light into reflected light and penetrating light, such as a grid polarizer, a multilayer polarizer, and a cholesteric liquid crystal polarizer, may be mentioned. Among these, as the linear polarizer, a polarizer containing polyvinyl alcohol is preferred.

If natural light is incident on the linear polarizer, only one beam of polarized light is transmitted. The polarization degree of this linear polarizer is not particularly limited, but it is preferably 98% or more, and more preferably 99% or more.

The thickness of the linear polarizer is preferably 5 μm to 80 μm.

Furthermore, the polarizing plate may be provided with a bonding layer for bonding the "linear polarizer" and the "optical anisotropic layer, a multilayer for transfer, or an optically anisotropic stack". As the bonding layer, a layer body obtained by curing a curable bonding agent can be used. As a curable adhesive, a thermosetting adhesive can also be used, but a photo-curable adhesive is preferably used. As the photocurable adhesive, a polymer or a reactive monomer may be used. In addition, the bonding agent may include a solvent, a photopolymerization initiator, and other additives, if necessary.

The photo-curable bonding agent is a bonding agent which is cured by irradiating light such as visible light, ultraviolet rays, and infrared rays. Among them, in terms of simple operation, a bonding agent that is cured by ultraviolet rays is preferred.

The thickness of the bonding layer is preferably 0.5 μm or more, more preferably 1 μm or more, more preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less. By setting the thickness of the bonding layer within the aforementioned range, good bonding can be achieved without impairing the optical properties of the optically anisotropic layer.

In addition, in the case where the polarizing plate includes an optically anisotropic stack, the polarizing plate may function as a circular polarizing plate. Here, the term "circular polarizer" does not only include a circular polarizer in a narrow sense, but also includes an elliptical polarizer. Such a circularly polarizing plate may include a linear polarizer, an optically anisotropic layer and a retardation layer in this order. In addition, such a circularly polarizing plate may sequentially include a linear polarizer, a retardation layer, and an optically anisotropic layer.

As described above, in the circular polarizing plate, it is preferable that the angle formed by the slow axis of the retardation layer is 45 ° or an angle close to the polarization absorption axis of the linear polarizer. The foregoing angle is specifically, preferably 45 ° ± 5 °, more preferably 45 ° ± 4 °, and even more preferably 45 ° ± 3 °.

The polarizing plate further includes an arbitrary layer body. Examples of the arbitrary layer body include a polarizer protective film layer. As the polarizer protective film layer, an arbitrary transparent film layer may be used. Among them, a thin film layer of a resin excellent in transparency, mechanical strength, thermal stability, moisture shielding property, and the like is preferred. Examples of such resins include acetate resins such as cellulose triacetate, polyester resins, polyether resins, polycarbonate resins, polyamide resins, polyimide resins, chain olefin resins, and cyclic resins. Olefin resin, (meth) acrylic resin, etc. In addition, as an arbitrary layer to be included in the polarizing plate, for example, a hard coating layer such as an impact-resistant polymethacrylic resin layer, a base layer for optimizing the smoothness of the film, a reflection suppressing layer, and an antifouling layer can be mentioned. These arbitrary layers may be provided with only one layer or two or more layers.

A polarizing plate can be manufactured by bonding a "linear polarizer" and "an optically anisotropic layer, a multilayer for transfer, or an optically anisotropic stack" using a bonding agent as required.

[5. Image display device]

An image display device of the present invention includes the polarizing plate of the present invention. In addition, the image display device of the present invention usually includes an image display element. In an image display device, a polarizing plate is usually disposed on the viewing side of the image display element. At this time, the direction of the polarizing plate can be arbitrarily set depending on the purpose of the polarizing plate. Therefore, the image display device may sequentially include: an optically anisotropic layer, a multilayer for transfer, or an optically anisotropic stack; a polarizer; and an image display element. In addition, the image display device may sequentially include a polarizer, an optically anisotropic layer, a multilayer for transfer or an optically anisotropic stack, and an image display element.

As an image display device, there are various types of visual image display elements, but as representative examples, a liquid crystal display device including a liquid crystal cell as an image display element and an organic EL display including an organic EL element as an image display element can be cited. Device.

The image display device of the present invention includes the optically anisotropic layer of the present invention as a constituent element, and thereby, reflection of natural light can be suppressed, and light for displaying an image must pass through polarized sunglasses. Furthermore, a display device having such an effect and having high durability and good color tone can be made.

『Examples』

The following examples are disclosed to illustrate the present invention in detail. However, the present invention is not limited to the embodiments disclosed below, and can be arbitrarily changed and implemented without departing from the scope of the patent application of the present invention and its equivalent scope. In the following description, the "%" and "part" of the amount are based on weight unless otherwise noted. In addition, the operations described below are performed in normal temperature and pressure atmosphere unless otherwise noted.

[Evaluation method]

[Optical properties of thin film]

The optical properties (phase difference, retardation, and inverse wavelength dispersion characteristics) of the sample layer (optical anisotropic layer, retardation layer, etc.) formed on a film (substrate film, etc.) are measured by the following methods.

The sample layer to be evaluated was bonded to a glass slide with an adhesive (the adhesive is "CS9621T" manufactured by Nitto Denko Corporation). After that, the film was peeled to obtain a sample including a glass slide and a sample layer. This sample was set on a hot stage of a phase difference meter (manufactured by Axometrics), and the in-plane retardation Re wavelength dispersion of the test material layer was measured. Here, the so-called wavelength dispersion of the in-plane retardation Re is a graph showing the in-plane retardation Re of each wavelength. For example, a graph is set in the coordinates where the horizontal axis is the wavelength and the vertical axis is the in-plane delay Re reveal. Based on the wavelength dispersion of the in-plane retardation Re of the sample layer thus obtained, the in-plane retardations Re (450), Re (550), Re (590) of the sample layer at the wavelengths of 450 nm, 550 nm, 590 nm, and 650 nm were obtained. ) And Re (650).

In addition, the slow axis of the sample layer is used as the rotation axis, and the table is tilted by 40 ° to measure the wavelength dispersion of the retardation Re40 of the sample layer in an oblique direction at an angle of 40 ° with respect to the thickness direction of the sample layer. Here, the wavelength dispersion of the retardation Re40 is a graph showing the in-plane retardation Re40 per wavelength. For example, a graph is disclosed in the coordinates where the horizontal axis is the wavelength and the vertical axis is the in-plane retardation Re40.

In addition, using a chirped coupler (made by Metricon), at a wavelength of 407 nm, 532 nm, and 633 nm, the test layer was measured for the "refractive index nx that belongs to the in-plane direction and gives the direction of maximum refractive index" and "that belongs to Refractive index ny "and" refractive index nz in the thickness direction "in the in-plane direction and perpendicular to the direction of nx, and the wavelengths of the refractive indices nx, ny, and nz are obtained by Cauchy fitting Dispersion. Here, the wavelength dispersion of the refractive index is a graph showing the refractive index of each wavelength. For example, a graph is disclosed by setting the horizontal axis as the wavelength and the vertical axis as the refractive index.

Then, based on the data of the retardation Re40 and the wavelength dispersion of the refractive index, the wavelength dispersion of the retardation Rth in the thickness direction of the sample layer was calculated. Here, the wavelength dispersion of the retardation Rth in the thickness direction is a graph showing the in-plane retardation Rth per wavelength, for example, in the coordinates where the horizontal axis is the wavelength and the vertical axis is the in-plane retardation Rth. The chart reveals. Then, based on the wavelength dispersion of the retardation Rth in the thickness direction of the sample layer thus obtained, the retardation Rth (450), Rth (550) in the thickness direction of the sample layer at the wavelengths of 450 nm, 550 nm, 590 nm, and 650 nm is obtained. , Rth (590) and Rth (650).

[thickness]

The thickness of the sample layer (optical anisotropic layer, retardation layer, etc.) formed on a film (substrate film; support film; multilayer film made of support film and retardation layer; etc.) Film thickness measuring device ("FILMETRICS" manufactured by FILMETRICS) measures.

[Haze change ratio]

A flat glass to which an optical adhesive (CS9621 manufactured by Nitto Denko Corporation) was attached was prepared. The optically anisotropic layer of the multilayer material for transfer was transferred to this plate glass to prepare a stack for haze measurement. Using this stack for haze measurement, the haze of the optically anisotropic layer was measured using a haze meter ("Haze-gard II" manufactured by Toyo Seiki Seisakusho, hereinafter also the same) in accordance with JIS K 7136: 2000. Haze measurement to obtain the initial haze value.

Subsequently, the stack for haze measurement was placed in an oven and heated. The heating temperature was set at 85 ° C, and the heating time was set at 100 hours. After the heating is completed, the haze is measured by the haze measurement again to obtain the haze value after heating. According to the initial haze value and the haze value after heating, calculate the haze change ratio (the haze value after heating / the initial haze value).

[Degree of curing]

An optically anisotropic layer for curing measurement is prepared by peeling the optically anisotropic layer from the substrate.

The infrared absorption spectrum of the optically anisotropic layer in the optically anisotropic layer for curing measurement was measured by the ATR method. Specifically, an ATR measuring device (model name "Nicolet iS 5N manufactured by Thermo Fisher SCIENTIFIC") was used to measure the surface of the stack for curing measurement under the condition of one reflection using ZeSe as a radon. The infrared absorption spectrum of the exposed optically anisotropic layer. The infrared absorption spectrum was obtained as the relationship between the wave number and the absorbance. The area of the peak that appeared near 810 cm ⁻¹ was measured as A _{C - H} and the measurement appeared at The area of the peak near 1720 cm ⁻¹ is taken as A _{C = O.} In the examples and comparative examples of this application, the positive C polymer has a C = O bond similar to C = O _MD , so the exclusion is similar. The quantification of the effect of C = O bonding (Reference Example 3). Based on these measurement results, the value of A _{C - H} / A _{C = O} (the original liquid crystalline compound) was obtained.

[B ^* ]

By the same operation as in the preparation of the stack for haze measurement, the optically anisotropic layer of the multilayer for transfer is transferred to a flat glass to prepare a stack for hue measurement. The transmittance of the hue measurement stack in the visible light region (380 nm to 780 nm) was measured with a spectrophotometer ("V-550" manufactured by JASCO Corporation) at intervals of 1.0 nm. Based on the obtained measurement results, the hue b ^{* is} calculated. The observation conditions at this time are set to a field of view of 2 °, a light source D65, and a data interval of 2 nm.

[Example 1]

1,3-Dioxo (DOL) and methyl isobutyl ketone (MIBK) were mixed to prepare a solvent. The mixing ratio of DOL and MIBK (DOL / MIBK, its weight ratio) is set to 80/20.

55 parts by weight of a photopolymerizable inverse-wavelength dispersive liquid crystal compound (CN point: 96 ° C) represented by the following formula (B1) so that the solid content concentration becomes 12%, Copolymer of diisobutyl butyrate and cinnamate "45 parts by weight, polymerization initiator (trade name" Irgacure Oxe04 ", manufactured by BASF) and 1.65 parts by weight of cross-linking agent (trade name" A- "TMPT", trimethylolpropane triacrylate, manufactured by Shin Nakamura Chemical Industry Co., Ltd.) 1.65 parts by weight was dissolved in a solvent to prepare a coating solution.

『Hua 11』

The "copolymer of diisopropyl fumarate and cinnamate" used in the preparation of the coating liquid has a repeating unit represented by the following formula (P1) and is represented by the following formula (P2) Representation of a repeating unit of polyfumarate (weight average molecular weight: 72,000). In the following formulae (P1) and (P2), R represents an isopropyl group, and the ratio of the number of repeating units m and n is m: n = 85: 15.

『Hua 12』

『Hua 13』

As the base film, an unstretched film (manufactured by Japan's Rui Weng Co., Ltd. with a glass transition temperature (Tg) of 163 ° C and a thickness of 100 μm) made of a resin containing an “alicyclic structure polymer” was prepared. Using a coating blade, a coating liquid is applied on the surface of the substrate film to form a coating liquid layer. The thickness of the coating liquid layer was adjusted so that the thickness of the obtained optically anisotropic layer was about 10 μm.

Thereafter, the coating liquid layer was dried in an oven at 85 ° C. for 5 minutes, and the solvent in the coating liquid layer was evaporated to obtain a multilayered body having a layered structure of (dry coating liquid layer) / (substrate film).

The dried coating liquid layer was irradiated with ultraviolet rays. Ultraviolet radiation is irradiated from the light source to the surface of the dry coating liquid layer side of the multilayer under the conditions of an illumination intensity of 300 mW / cm ² and an integrated light amount of 600 mJ / cm ² by using an irradiation device equipped with a high-pressure mercury light source. UV ". By this ultraviolet irradiation, the dried coating liquid layer is cured to form an optically anisotropic layer, so as to obtain a multilayer material for transfer having a layered structure of (optical anisotropic layer) / (base film). The optical anisotropic layer of the obtained multilayer material for transfer was measured for optical properties, and nx (A), ny (A), nz (A), Rth (A450) / Rth (A550), Rth ( A650) / Rth (A550), Re (A590) and Rth (A590). In addition, the curing degrees A, b ^* and haze change ratios of the optically anisotropic layer were measured.

[Examples 2 to 4 and Comparative Examples 1 to 4]

Except that the integrated light quantity was changed to the value disclosed in Table 1, the same procedure as in Example 1 was used to obtain and evaluate a multilayer material for transfer.

The results of the examples and comparative examples are collectively disclosed in Tables 1 and 2.

"Table 1"

"Table 2"

It is clear from the results of the examples and comparative examples that the optically anisotropic layer of the example having the specific curing degree A specified in the present application has less increase in haze due to heating, so it is durable. Sex is high. In addition, it can be seen that the optically anisotropic layer of the example has a b ^* value of 2.2 or less and a good hue.

[Reference Example 1: Confirmation of the wavelength dispersion property of the inverse wavelength dispersion liquid crystal compound represented by the aforementioned formula (B1)]

100 parts by weight of a photopolymerizable reverse wavelength dispersion liquid crystal compound represented by the aforementioned formula (B1), 3 parts by weight of a photopolymerization initiator ("Irgacure 379EG" manufactured by BASF Corporation) and a surfactant (manufactured by DIC Corporation) were mixed "MEGAFAC F-562") 0.3 parts by weight, and further added a mixed solvent of cyclopentanone and 1,3-dioxo (weight ratio of cyclopentanone: 1,3-dioxane = 22% by weight) 4: 6) As a diluting solvent, it was heated to 50 ° C to dissolve it. The obtained mixture was filtered through a membrane filter having a pore size of 0.45 μm to obtain a liquid crystal composition.

An unstretched film ("ZEONOR film" manufactured by Ruion Co., Ltd.) made of a resin containing "alicyclic structure polymer" is prepared. By rubbing this unstretched film, an alignment substrate is prepared.

The liquid crystal composition was coated on the alignment substrate with a bar coater to form a layer of the liquid crystal composition. The thickness of the layer of the liquid crystal composition is adjusted so that the thickness of the optically anisotropic layer obtained after curing is approximately 2.3 μm.

After that, the layer of the liquid crystal composition was dried in an oven at 110 ° C. for about 4 minutes. While the solvent in the liquid crystal composition was evaporated, the inverse wavelength dispersion liquid crystal compound contained in the liquid crystal composition was uniformly aligned.

Thereafter, the layered body of the liquid crystal composition is irradiated with ultraviolet rays using an ultraviolet irradiation device. This ultraviolet irradiation is performed under a nitrogen environment while the alignment substrate is fixed to the SUS board with an adhesive tape. A layer of the liquid crystal composition is cured by irradiation of ultraviolet rays, and a sample film including an optically anisotropic layer and an alignment substrate is obtained.

For this sample film, the retardation wavelength dispersion (measured by Axometrics) was measured for retardation in the plane. Since the alignment substrate does not have in-plane retardation, the in-plane retardation obtained by the aforementioned measurement reveals the in-plane retardation of the optically anisotropic layer. As a result of the measurement, the in-plane retardations Re (450), Re (550), and Re (650) at the wavelengths of 450 nm, 550 nm, and 650 nm satisfy Re (450) <Re (550) <Re (650). Therefore, it was confirmed that the photopolymerizable reverse-wavelength dispersive liquid crystal compound represented by the aforementioned formula (B1) is an in-plane retardation that exhibits reverse-wavelength dispersibility when uniformly aligned.

[Reference Example 2: Confirmation that the copolymer of diisopropyl fumarate and cinnamate conforms to the positive C polymer]

A copolymer of diisopropyl fumarate and cinnamate was added to N-methylpyrrolidone so that the solid content concentration was 12% by weight, and the polymer was dissolved at room temperature to obtain a polymer. Solution.

An unstretched film ("ZEONOR film" manufactured by Ruion Co., Ltd.) made of a resin containing "alicyclic structure polymer" is prepared. The aforementioned polymer solution was coated on the unstretched film using a coater to form a layer of the polymer solution. Then, the sample was dried by drying in an oven at 85 ° C. for about 10 minutes to evaporate the solvent to obtain a sample film having a polymer film and an unstretched film having a thickness of about 10 μm.

This sample film was set on a stage of a phase difference meter (manufactured by Axometrics), and the in-plane retardation Re0 of the test sample film was measured at a measurement wavelength of 590 nm. Since the unstretched film is an optically isotropic film, the measured in-plane retardation Re0 represents the in-plane retardation Re0 of the polymer film. As a result of the measurement, the in-plane retardation Re0 is Re0 ≦ 1 nm, so nx (P) ≧ ny (P) can be confirmed, and these values are the same or close to each other.

After that, the slow axis of the polymer film was used as the rotation axis of the table, and the table was tilted by 40 °, and the retardation Re40 was measured in an inclined direction at an angle of 40 ° with respect to the thickness direction of the sample film. Then, by this measurement, the slow axis direction of the polymer film is measured. If the "slow axis direction" is perpendicular to the "rotation axis of the table", it can be determined that nz (P)> nx (P), otherwise, if the "slow axis direction" is parallel to the "rotation axis of the table", it can be determined ny (P)> nz (P). As a result of the measurement, since the slow axis direction is perpendicular to the rotation axis of the table, the refractive indices nx (P) and nz (P) of the polymer film can be determined to satisfy nz (P)> nx (P).

Therefore, it was confirmed that when a copolymer of diisopropyl fumarate and cinnamate was formed by a coating method using a solution of the copolymer, the refractive index of the polymer film satisfies nz (P)> nx (P) ≧ ny (P). Therefore, it was confirmed that the copolymer of diisopropyl fumarate and cinnamate conforms to a positive C polymer.

[Reference Example 3]

Except changing the amounts of the mesogen compound and the positive C polymer in the coating liquid, the same operation as in Example 3 was performed to obtain a plurality of transfer multilayers. The infrared absorption spectrum of each of the optically anisotropic layers of the obtained multilayered material for transfer was measured by the ATR method. The area of the peak of the obtained infrared absorption spectrum in the vicinity of 1720 cm ⁻¹ was obtained as A _{C = O.} As a result, the results disclosed in Table 3 were obtained. Based on these values, the constant a _{C = O} (the mesogen) is calculated by the least square method. As a result, _{values of} a _{C = O} (liquid crystal compound) = 12.93 and a _{C = O} (polymer) = 21.42 were obtained. Based on these values, the values of A _{C = O} (liquid crystal compound) in the examples and comparative examples were obtained and provided for the calculation of the degree of curing A.

"table 3"

no.

no.

Claims (18)

An optically anisotropic layer is an optically anisotropic layer including a positive C polymer, a mesogen compound, and a polymer of a mesogen compound. The positive C polymer is obtained by using the positive type When the film of the C polymer solution is formed by the coating method of the C polymer solution, the film satisfies the polymer of formula (1), the mesogen compound is a compound having a mesogen skeleton and an acrylate structure, and the optical The anisotropic layer satisfies equations (2) and (3): nz (P)> nx (P) ≧ ny (P) Equation (1) nz (A)> nx (A) ≧ ny (A) Equation (2) ) 0.073 <A _{C - H} / A _{C = O} (liquid crystal compound) <0.125 Formula (3) wherein nx (P), ny (P) and nz (P) are the main refractive indices of the aforementioned film, and nx (A ), ny (a) and nz (a) based the principal refractive index of the optically anisotropic layer, a _{C - H} in the infrared absorption spectrum system the optically anisotropic layers, the crystal structure of the acrylic compound of the original the outer surface having the C-H bending vibration related bonding of infrared absorption, a _{C = O} (mesogen compound) -based optically anisotropic layer of the infrared rays in In the received spectrum, infrared absorption related to the stretching vibration of the C = O bond of the aforementioned acrylate structure of the aforementioned mesogen compound is derived from that of the C = O bond of the aforementioned acrylate structure derived from the aforementioned mesogen compound. The sum of infrared absorption related to the stretching vibration of C = O bond. The optically anisotropic layer according to claim 1, wherein the mesogen compound is a compound that exhibits in-plane retardation of inverse wavelength dispersion when uniformly aligned. The optically anisotropic layer as described in claim 1 or 2, which satisfies formulas (4) and (5): 0.50 <Rth (A450) / Rth (A550) <1.00 Formula (4) 1.00 ≦ Rth (A650) /Rth(A550)<1.25 Formula (5) where Rth (A450) is the retardation of the aforementioned optical anisotropic layer in the thickness direction of 450 nm, and Rth (A550) is the aforementioned optical anisotropic layer at the wavelength of 550 nm. The retardation in the thickness direction, Rth (A650) is the retardation in the thickness direction of the wavelength of 650 nm of the optically anisotropic layer. The optically anisotropic layer according to claim 1 or 2, wherein the aforementioned mesogen compound is represented by the following formula (I): "化 1" (In the aforementioned formula (I): Y ¹ to Y ⁸ each independently represent a chemical single bond, -O-, -S-, -O-C (= O)-, -C (= O) -O- , -O-C (= O) -O-, -NR ¹ -C (= O)-, -C (= O) -NR ^1- , -O-C (= O) -NR ^1- , -NR ¹ -C (= O) -O-, -NR ¹ -C (= O) -NR ^1- , -O-NR ¹ -or -NR ¹ -O-; here, R ¹ represents a hydrogen atom or a carbon number 1 to 6 alkyl groups; G ¹ and G ² each independently represent a divalent aliphatic group having 1 to 20 carbon atoms which may have a substituent; and each of the aliphatic groups in the aforementioned aliphatic group may be interposed by One or more of -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O-C (= O) -O-, -NR ² -C (= O)-, -C (= O) -NR ^2- , -NR ² -or -C (= O)-; among them, the case where two or more of -O- or -S- are adjacent and intermediary respectively is excluded; Here, R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Z ¹ and Z ² each independently represent an alkenyl group having 2 to 10 carbon atoms which may be substituted by a halogen atom; and A ^x represents a compound selected from an aromatic hydrocarbon ring and an aromatic group. At least one of the group formed by heterocycles Ring carbon atoms of an organic group of 2 to 30; A ^y represents a hydrogen atom, can be a substituent having a carbon number of alkyl group of 1 to 20, also having a carbon number of the substituent of the alkenyl group having 2 to 20, also having A cycloalkyl group having 3 to 12 carbon atoms as a substituent, an alkynyl group having 2 to 20 carbon atoms as a substituent, -C (= O) -R ³ , -SO ₂ -R ⁴ , -C (= S ) NH-R ⁹ or an organic group having 2 to 30 carbon atoms in at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring; here, R ³ represents a carbon number 1 which may also have a substituent An alkyl group of -20, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 3 to 12 carbon atoms or an aromatic hydrocarbon ring group having 5 to 12 carbon atoms which may have a substituent; R ⁴ represents Alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, phenyl group, or 4-methylphenyl group; R ⁹ represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, and may have a substituent Alkenyl group having 2 to 20 carbon atoms, cycloalkyl group having 3 to 12 carbon atoms which may have a substituent, or aryl group having 5 to 20 carbon atoms which may have a substituent; the above-mentioned A ^x and A ^y have The aromatic ring may also have a substituent; and the aforementioned A ^x and A ^y may form a ring together; ¹ represents a trivalent aryl group which may also have a substituent; A ² and A ³ each independently represent a divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms which may also have a substituent; A ⁴ and A ⁵ each independently may also have Divalent aryl group having 6 to 30 carbon atoms of the substituent; Q ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent; m and n each independently represent 0 or 1; wherein, Z ^1- One or both of Y ⁷ － and Y ^{8 －} Z ² is acryloxy). The optically anisotropic layer according to claim 1 or 2, wherein the aforementioned mesogen compound contains at least one selected from the group consisting of a benzothiazole ring and a combination of a cyclohexyl ring and a benzene ring in its molecular structure. . The optically anisotropic layer according to claim 1 or 2, wherein the aforementioned positive C polymer is at least one selected from the group consisting of polyvinylcarbazole, polyfumarate, and cellulose derivatives Polymer. The optically anisotropic layer according to claim 1 or 2, wherein the proportion of the aforementioned mesogen compound and its polymer in the total solid content of the optically anisotropic layer is 20% by weight or more and 60% by weight or less. The optically anisotropic layer according to claim 1 or 2, which satisfies formulas (6) and (7): Re (A590) ≦ 10 nm Formula (6) −200 nm ≦ Rth (A590) ≦ −10 nm In formula (7), Re (A590) is a retardation of the aforementioned optical anisotropic layer in a plane of a wavelength of 590 nm, and Rth (A590) is a retardation of the aforementioned optical anisotropic layer in a thickness direction of a wavelength of 590 nm. A multilayer material for transfer, comprising a substrate and the optically anisotropic layer according to any one of claims 1 to 8. An optically anisotropic stack comprising the optically anisotropic layer and the retardation layer according to any one of claims 1 to 8, the retardation layer satisfying formula (8): nx (B)> ny ( B) ≧ nz (B) In the formula (8), nx (B), ny (B), and nz (B) are the principal refractive indices of the retardation layer. The optically anisotropic stack as described in claim 10, wherein the phase difference layer satisfies Expressions (9) and (10): 0.75 <Re (B450) / Re (B550) <1.00 Expression (9) 1.01 <Re (B650) / Re (B550) <1.25 Formula (10), where Re (B450) is the retardation of the aforementioned retardation layer in the plane of the wavelength of 450 nm, and Re (B550) is the retardation of the aforementioned retardation layer in the plane of the wavelength of 550 nm Re (B650) is the retardation of the retardation layer in the plane of the wavelength of 650 nm. The optically anisotropic stacked body according to claim 11, wherein the retardation layer includes a liquid crystal compound for a retardation layer represented by the following formula (II): "化 2" (In the aforementioned formula (II): Y ¹ to Y ⁸ each independently represent a chemical single bond, -O-, -S-, -O-C (= O)-, -C (= O) -O- , -O-C (= O) -O-, -NR ¹ -C (= O)-, -C (= O) -NR ^1- , -O-C (= O) -NR ^1- , -NR ¹ -C (= O) -O-, -NR ¹ -C (= O) -NR ^1- , -O-NR ¹ -or -NR ¹ -O-; here, R ¹ represents a hydrogen atom or a carbon number 1 to 6 alkyl groups; G ¹ and G ² each independently represent a divalent aliphatic group having 1 to 20 carbon atoms which may have a substituent; and each of the aliphatic groups in the aforementioned aliphatic group may be interposed by One or more of -O-, -S-, -O-C (= O)-, -C (= O) -O-, -O-C (= O) -O-, -NR ² -C (= O)-, -C (= O) -NR ^2- , -NR ² -or -C (= O)-; among them, the case where two or more of -O- or -S- are adjacent and intermediary respectively is excluded; Here, R ² represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Z ¹ and Z ² each independently represent an alkenyl group having 2 to 10 carbon atoms which may be substituted by a halogen atom; and A ^x represents a compound selected from an aromatic hydrocarbon ring and an aromatic group. At least one of the group formed by heterocycles An organic group having 2 to 30 carbon atoms in the aromatic ring; A ^y represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, or A cycloalkyl group having 3 to 12 carbon atoms having a substituent, an alkynyl group having 2 to 20 carbon atoms having a substituent, -C (= O) -R ³ , -SO ₂ -R ⁴ , -C (= S) NH-R ⁹ or an organic group having 2 to 30 carbon atoms in at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring; here, R ³ represents a carbon number which may also have a substituent An alkyl group of 1 to 20, an alkenyl group of 2 to 20 carbons which may have a substituent, a cycloalkyl group of 3 to 12 carbons or an aromatic hydrocarbon ring group of 5 to 12 carbons which may have a substituent; R ⁴ Represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a phenyl group, or 4-methylphenyl group; R ⁹ represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, and may have The alkenyl group having 2 to 20 carbon atoms of the substituent, the cycloalkyl group having 3 to 12 carbon atoms which may have a substituent or the aryl group having 5 to 20 carbon atoms which may have a substituent; the aforementioned A ^x and A ^y The aromatic ring may also have a substituent; and, the aforementioned A ^x and A ^y may form a ring together; A ¹ represents a trivalent aryl group which may also have a substituent; A ² and A ³ each independently represent a bivalent alicyclic hydrocarbon group having 3 to 30 carbon atoms which may also have a substituent; A ⁴ and A ⁵ each independently represent A bivalent aryl group having 6 to 30 carbons having a substituent; Q ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbons having a substituent; m and n each independently represent 0 or 1). A polarizing plate comprising: a linear polarizer; and the optically anisotropic layer according to any one of claims 1 to 8, the multilayer material for transfer according to claim 9, or the claims 10 to 12 The optically anisotropic stack according to any one of the above. An image display device including the polarizing plate according to claim 13. An image display device, comprising: an optically anisotropic stack according to any one of claims 10 to 12; a linear polarizer; and an image display element; the image display element is a liquid crystal cell or an organic electroluminescent device. Light emitting element. A method for producing an optically anisotropic layer according to any one of claims 1 to 8, comprising: preparing a material including a positive C polymer, a mesogen, a solvent, a photopolymerization initiator, and a crosslinking agent. A step of applying a coating liquid; a step of applying the coating liquid on a support surface to obtain a coating liquid layer; and a step of irradiating the coating liquid layer with light to cure the coating liquid layer. The method for producing an optically anisotropic layer according to claim 16, wherein in the coating solution, a ratio of the photopolymerization initiator to 100 parts by weight of the original mesogen compound is 1 to 10 parts by weight. The ratio of the crosslinking agent to 100 parts by weight of the aforementioned mesogen compound is 1 to 10 parts by weight. The manufacturing method according to claim 16 or 17, wherein an integrated light amount of the aforementioned light to be irradiated is 600 mJ / cm ² to 5000 mJ / cm ² .