JP7329926B2 - Laminate and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a laminate containing a vertically aligned liquid crystal cured film and a horizontally aligned liquid crystal cured film, and an elliptically polarizing plate and an organic EL display including the laminate. It also relates to a method for manufacturing the laminate.

An elliptically polarizing plate is an optical member in which a polarizing plate and a retardation plate are laminated. is used to prevent A so-called λ/4 plate is generally used as a retardation plate that constitutes the elliptically polarizing plate.

For the retardation plate constituting the elliptically polarizing plate, a retardation plate exhibiting reverse wavelength dispersion is preferable in that it tends to exhibit uniform retardation performance over a wide wavelength range of visible light. As such a retardation plate, a horizontally aligned liquid crystal cured film obtained by polymerizing and curing a polymerizable liquid crystal compound exhibiting reverse wavelength dispersion in a state of being aligned in the horizontal direction with respect to the plane of the retardation plate. Retardation plates are known. Further, by incorporating a vertically aligned liquid crystal cured film into an elliptical polarizer provided with a horizontally aligned liquid crystal cured film, oblique hue change during black display when the elliptical polarizer is used in an organic EL display device can be suppressed. Patent Document 1 describes a laminate including a vertically aligned liquid crystal cured film formed on a vertical alignment film and a horizontally aligned liquid crystal cured film formed on a horizontal alignment film. ing.

JP 2015-163935 A

However, a laminate including a vertically aligned liquid crystal cured film and a horizontally aligned liquid crystal cured film as described in the above patent document is conventionally prepared after independently preparing the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film. , and are often produced by laminating them together with an adhesive or the like. In addition, conventionally, the production of a vertically aligned liquid crystal cured film requires a vertical alignment film for aligning the polymerizable liquid crystal compound in the vertical direction, and it is necessary to form the vertically aligned film before forming the vertically aligned liquid crystal cured film. There is Therefore, there is a problem that the manufacturing process of a conventional laminate including a vertically aligned liquid crystal cured film and a horizontally aligned liquid crystal cured film tends to be complicated, and productivity tends to decrease.

Therefore, the present invention provides a novel solution to the above problem, that is, it is possible to form a vertically aligned liquid crystal cured film without forming a vertically aligned liquid crystal film and then continuously form a horizontally aligned liquid crystal cured film. It aims at providing a laminated body and its manufacturing method.

Furthermore, in the study of the above solution by the present inventors, when a vertically aligned liquid crystal cured film is formed without forming a vertical alignment film, the liquid crystal orientation tends to decrease, and on the vertically aligned liquid crystal cured film When forming a horizontal liquid crystal cured film through a horizontal alignment film, compared with a laminate in which a vertical alignment liquid crystal cured film and a horizontal alignment liquid crystal cured film are bonded by an adhesive layer, the vertical alignment liquid crystal cured film It was found that the adhesiveness between the liquid crystal and the horizontally aligned liquid crystal cured film tends to decrease.

Therefore, the present invention provides a laminate including a horizontally aligned liquid crystal cured film laminated on a vertically aligned liquid crystal cured film formed without a vertically aligned liquid crystal film, and improving the liquid crystal orientation and the vertically aligned liquid crystal cured film. It is also an object of the present invention to improve adhesion with a horizontally aligned liquid crystal cured film formed on the vertically aligned liquid crystal cured film with a horizontal alignment film interposed therebetween.

The inventors of the present invention have completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention includes the following aspects.
[1] A laminate comprising a substrate, a vertically aligned liquid crystal cured film, a horizontally aligned film, and a horizontally aligned liquid crystal cured film in this order,
The vertically aligned liquid crystal cured film is a cured product of a polymerizable liquid crystal composition cured in a state in which the polymerizable liquid crystal compound is aligned in a direction perpendicular to the plane of the liquid crystal cured film, and the horizontally aligned liquid crystal cured film is polymerized. A cured product of a polymerizable liquid crystal composition cured in a state in which the liquid crystal compound is aligned in the horizontal direction with respect to the plane of the cured liquid crystal film,
a photo-alignment film in which the vertically aligned liquid crystal cured film contains a vertical alignment accelerator, and the horizontal alignment film is formed of a (meth)acrylic polymer;
A laminate, wherein the total thickness from the substrate-side surface of the vertically aligned liquid crystal cured film to the surface of the horizontally aligned liquid crystal cured film opposite to the horizontal alignment film is 10 μm or less.
[2] The laminate according to [1] above, wherein the substrate is a peelable substrate.
[3] The laminate according to [1] or [2] above, wherein the substrate, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film are adjacent to each other in this order.
[4] The laminate according to any one of [1] to [3], wherein the horizontal alignment film has a thickness of 10 to 5000 nm.
[5] The laminate according to any one of [1] to [4] above, wherein the horizontal alignment film is a photo-alignment film formed from a polymer having an azo group or a cinnamoyl group.
[6] The laminate according to any one of [1] to [5] above, wherein the horizontally aligned liquid crystal cured film has at least one or more absorption maxima within a wavelength range of 300 to 400 nm.
[7] The horizontal alignment liquid crystal cured film is represented by the following formula (1):
ReA(450)/ReA(550)≤1 (1)
[In the formula (1), ReA (450) represents the in-plane retardation value at a wavelength of 450 nm in the in-plane direction of the horizontally aligned liquid crystal cured film, and ReA (550) represents the in-plane direction of the horizontally aligned liquid crystal cured film at a wavelength of 550 nm represents the in-plane retardation value at]
The laminate according to any one of [1] to [6], which satisfies
[8] The laminate according to any one of [1] to [7], wherein the vertically aligned liquid crystal cured film contains a nonionic silane compound as a vertically aligned accelerator.
[9] Any one of the above [1] to [8], wherein the vertically aligned liquid crystal cured film contains a nonionic silane compound as a vertical alignment accelerator, and the nonionic silane compound is a silane coupling agent. laminate.
[10] The laminate according to any one of [1] to [9], wherein the vertically aligned liquid crystal cured film contains an ionic compound composed of non-metallic atoms as a vertically aligned accelerator.
[11] The above [1] to [10], wherein the vertically aligned liquid crystal cured film contains an ionic compound composed of non-metallic atoms as a vertical alignment accelerator, and the ionic compound has a molecular weight of 100 or more and 10,000 or less. The laminate according to any one of .
[12] The laminate according to any one of [1] to [11], wherein the vertically aligned liquid crystal cured film contains an ionic compound composed of a nonionic silane compound and a non-metal atom as a vertical alignment accelerator.
[13] A horizontally aligned liquid crystal cured film is a cured liquid crystal film obtained by curing a polymerizable liquid crystal compound having at least one radically polymerizable group while being aligned horizontally with respect to the in-plane direction of the cured liquid crystal film, Further, the vertically aligned cured liquid crystal film is a cured liquid crystal film obtained by curing a polymerizable liquid crystal compound having at least one radically polymerizable group in a state vertically aligned with respect to the in-plane direction of the cured liquid crystal film. The laminate according to any one of [1] to [12].
[14] The laminate according to any one of [1] to [13], wherein the vertically aligned liquid crystal cured film has at least one maximum absorption between wavelengths of 300 to 400 nm.
[15] The vertically aligned liquid crystal cured film is represented by the following formula (2):
RthC(450)/RthC(550)≤1 (2)
[In formula (2), RthC(450) represents the thickness direction retardation value of the vertically aligned liquid crystal cured film at a wavelength of 450 nm, and RthC(550) represents the thickness direction retardation value of the vertically aligned liquid crystal cured film at a wavelength of 550 nm. represents]
The laminate according to any one of [1] to [14], which satisfies the above.
[16] An elliptically polarizing plate comprising the laminate according to any one of [1] to [15] and a polarizing film.
[17] An elliptically polarizing plate comprising a laminate obtained by removing the substrate from the laminate according to any one of [1] to [15] above, and a polarizing film.
[18] The elliptically polarizing plate of [16] or [17] above, wherein the angle formed by the slow axis of the horizontally aligned liquid crystal cured film constituting the laminate and the absorption axis of the polarizing film is 45±5°. .
[19] An organic EL display device comprising the elliptically polarizing plate according to any one of [16] to [18].
[20] A method for producing a laminate according to any one of [1] to [15],
forming a coating film of a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film containing a polymerizable liquid crystal compound, and forming a vertically aligned liquid crystal cured film from the coating film;
a step of forming a coating film of a composition for forming a horizontal alignment film, and forming a horizontal alignment film from the coating film;
A production method comprising the steps of forming a coating film of a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film containing a polymerizable liquid crystal compound, and forming a horizontally aligned liquid crystal cured film from the coating film, in this order.
[21] The manufacturing method according to [20] above, wherein the step of forming a vertically aligned liquid crystal cured film, the step of forming a horizontal alignment film, and the step of forming a horizontally aligned liquid crystal cured film are successively performed in this order.

According to the present invention, a vertically aligned liquid crystal cured film is formed without forming a vertical alignment film, and a horizontally aligned liquid crystal cured film is continuously formed on the vertically aligned liquid crystal cured film via a horizontal alignment film. can be provided. Furthermore, in the laminate, the liquid crystal orientation is improved, and the adhesion between the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film formed on the vertically aligned liquid crystal cured film through the horizontal alignment film. can be improved.

It is a schematic sectional drawing which shows an example of the layer structure of the laminated body of this invention. It is a schematic sectional drawing which shows an example of the layer structure of the laminated body of this invention. It is a schematic sectional drawing which shows an example of the layer structure of the laminated body of this invention.

The laminate of the present invention includes a substrate, a vertically aligned liquid crystal cured film, a horizontally aligned film, and a horizontally aligned liquid crystal cured film in this order. An example of the layer structure of the laminate of the present invention will be described below with reference to FIGS. 1 to 3, but the laminate of the present invention is not limited to these embodiments.

A laminate 11 shown in FIG. 1 is formed by laminating a substrate 1, a vertically aligned liquid crystal cured film 2, a horizontally aligned film 3, and a horizontally aligned liquid crystal cured film 4 in this order. In the laminate 11 shown in FIG. 1, the vertically aligned liquid crystal cured film 2 is formed directly on the substrate 1 without a layer having a vertical alignment control force (hereinafter also referred to as a “vertical alignment film”). , the substrate 1 and the vertically aligned liquid crystal cured film 2 are adjacent to each other. The laminate of the present invention includes, in addition to the substrate, the vertically aligned liquid crystal cured film, the horizontally aligned film, and the horizontally aligned liquid crystal cured film, other layers as long as they do not affect the effects of the present invention. may be Other layers include, for example, a cured resin layer such as a protective layer and a hard coat layer, a horizontally aligned liquid crystal cured film, and an adhesive layer for bonding the laminate of the present invention to a polarizing film or the like. .

As a laminate containing other layers, for example, in a laminate 11 shown in FIG. A horizontal alignment film 3 and a horizontal alignment liquid crystal cured film 4 are stacked on the vertically aligned liquid crystal cured film 2 . Furthermore, in the laminate 11 shown in FIG. 3, which is another aspect of the present invention, the base material 1 and the vertically aligned liquid crystal cured film 2 are laminated via the cured resin layer 5, and the vertically aligned liquid crystal A cured film 2 and a horizontal alignment film 3 are laminated with a cured resin layer 5 interposed therebetween, and a horizontally aligned liquid crystal cured film 4 is laminated on the horizontal alignment film 3 . An elliptically polarizing plate can be obtained by laminating the laminate 11 and the polarizing film via an adhesive layer. At this time, either side of the vertically aligned liquid crystal cured film 2 or the horizontally aligned liquid crystal cured film 4 of the laminate 11 may be attached to the polarizing film. For example, the substrate 1 of the laminate 11 in FIG. After that, the vertically aligned liquid crystal cured film 2 may be adhered to the polarizing film via an adhesive layer, or the horizontally aligned liquid crystal cured film 4 of the laminate 11 in FIG. You may bond through an adhesive layer. Hereinafter, in the present specification, among the layer configurations of the laminate of the present invention, the minimum layer configuration including the substrate, the vertically aligned liquid crystal cured film, the horizontal alignment film and the horizontally aligned liquid crystal cured film in this order is referred to as the “basic It is also called layer structure (I). That is, for example, when the laminate of the present invention is composed of a substrate, a vertically aligned liquid crystal cured film, a horizontal alignment film, a first horizontally aligned liquid crystal cured film, and a second horizontally aligned liquid crystal cured film, the substrate is the most Up to the horizontally aligned liquid crystal cured film (in this case, the first horizontally aligned liquid crystal cured film) on the substrate side constitutes the basic layer configuration (I) of the laminate of the present invention.

In the laminate of the present invention, the total film thickness from the surface of the vertically aligned liquid crystal cured film on the substrate side to the surface of the horizontally aligned liquid crystal cured film opposite to the horizontal alignment film (between a and b in FIGS. 1 to 3 The thickness (hereinafter also referred to as “total film thickness T1”) is 10 μm or less. Since the laminate of the present invention can form a horizontally aligned liquid crystal cured film directly on a vertically aligned liquid crystal cured film through a horizontal alignment film, the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film are separately formed. After production, the total film thickness T1 can be made thinner compared to a conventional laminate obtained by laminating both with a pressure-sensitive adhesive or an adhesive. Reducing the total thickness T1 of the laminate can contribute to reducing the thickness of the entire laminate and the elliptically polarizing plate including the laminate. The total film thickness T1 of the laminate of the present invention is preferably 7 μm or less, more preferably 5 μm or less. The lower limit of the total film thickness T1 is not particularly limited, and is usually 1 μm or more, and may be, for example, 1.5 μm or more. In addition, when the laminate of the present invention further comprises a vertically aligned liquid crystal cured film and/or a horizontally aligned liquid crystal cured film on the side opposite to the horizontal alignment film of the horizontally aligned liquid crystal cured film of the basic layer configuration (I), the above total The film thickness T1 means the total film thickness from the substrate-side surface of the vertically aligned liquid crystal cured film constituting the basic layer structure (I) to the surface of the horizontally aligned liquid crystal cured film opposite to the horizontal alignment film.

In the laminate of the present invention, the vertically aligned liquid crystal cured film can be formed on the substrate or on a layer having no vertical alignment regulating force provided on the substrate without interposing the vertical alignment film. In the laminate of the present invention, the vertically aligned liquid crystal cured film can be formed without a vertically aligned film. Therefore, the number of steps for manufacturing the laminate is reduced, and the laminate can be manufactured with high productivity. That is, in one aspect of the laminate of the present invention, the substrate and the vertically aligned liquid crystal cured film are laminated without interposing a vertical alignment film. In a more preferred aspect, the laminate of the present invention comprises a substrate, A vertically aligned liquid crystal cured film, a horizontally aligned film, and a horizontally aligned liquid crystal cured film are adjacent to each other in this order. In the laminate of the present invention having such a layer structure, a vertically aligned liquid crystal cured film can be formed on a substrate without a vertical alignment film, and furthermore, a horizontal alignment film is formed on the vertically aligned liquid crystal cured film via a horizontal alignment film. Since the horizontally aligned liquid crystal cured film can be continuously formed, the laminate can be manufactured with high productivity.

Hereinafter, each configuration of the laminate of the present invention will be described in detail.
[Vertical alignment liquid crystal cured film]
The vertically aligned liquid crystal cured film constituting the laminate of the present invention is a cured product of a polymerizable liquid crystal composition cured in a state in which the polymerizable liquid crystal compound is aligned in a direction perpendicular to the plane of the liquid crystal cured film. In the present invention, the vertically aligned liquid crystal cured film contains a vertically aligned accelerator. That is, in the present invention, the polymerizable liquid crystal composition forming the vertically aligned liquid crystal cured film contains a vertically aligned accelerator. In the present invention, the vertical alignment promoter means a material that promotes liquid crystal alignment of the polymerizable liquid crystal compound in the direction perpendicular to the film plane. By including a vertical alignment accelerator in the cured vertically aligned liquid crystal film, the cured vertically aligned liquid crystal film can be formed without a vertically aligned film. Thereby, in the laminate of the present invention, it is not necessary to form a vertically aligned liquid crystal cured film, the production process of the laminate is simplified, and the laminate can be produced with good productivity. When a horizontal alignment film and a cured horizontal alignment liquid crystal film are formed on the cured vertically aligned liquid crystal film, the alignment of the cured horizontal alignment liquid crystal film tends to deteriorate. Although the reason is not clear, additives such as leveling agents contained in the vertically aligned liquid crystal cured film lower the surface energy, and the orientation of the liquid crystal compound tends to be impaired when the horizontal aligned liquid crystal cured film is formed on the upper layer. It is estimated to be. In particular, in the case of forming a vertically aligned liquid crystal cured film without a vertical alignment film, the alignment accelerator is further included, so the effect thereof becomes more pronounced.

Examples of the vertical alignment accelerator for promoting vertical alignment of the polymerizable liquid crystal compound include nonionic silane compounds and ionic compounds composed of nonmetallic atoms. The vertically aligned liquid crystal cured film preferably contains at least one of a nonionic silane compound and an ionic compound consisting of nonmetallic atoms, and contains both the nonionic silane compound and an ionic compound consisting of nonmetallic atoms. is more preferable.

When the polymerizable liquid crystal composition forming the vertically aligned liquid crystal cured film contains a nonionic silane compound, the nonionic silane compound lowers the surface tension of the polymerizable liquid crystal composition, and the polymerizable liquid crystal composition is formed. In the dry coating film, the nonionic silane compound tends to be unevenly distributed at the interface between the dry coating film and the air. It tends to be oriented perpendicular to the As a result, the cured liquid crystal film can be formed while maintaining the vertically aligned state of the polymerizable liquid crystal compound.

A nonionic silane compound is a compound that is nonionic and contains Si element. Nonionic silane compounds include, for example, silicon polymers such as polysilanes, silicone resins such as silicone oils and silicone resins, and organic and inorganic silane compounds such as silicone oligomers, silsessiloxanes and alkoxysilanes (more specifically, includes silane coupling agents, etc.).
These nonionic silane compounds may be used singly or in combination of two or more. Among them, a silane coupling agent is preferable from the viewpoint of further improving the adhesion to the adjacent layer.

The nonionic silane compound may be of the silicone monomer type or of the silicone oligomer (polymer) type. In the form of (monomer)-(monomer) copolymer, the silicone oligomers are 3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercapto Mercaptopropyl group-containing copolymers such as propyltriethoxysilane-tetramethoxysilane copolymer and 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer; mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetra Mercaptomethyl group-containing copolymers such as ethoxysilane copolymers, mercaptomethyltriethoxysilane-tetramethoxysilane copolymers and mercaptomethyltriethoxysilane-tetraethoxysilane copolymers; 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymers, 3 -Methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane- Tetramethoxysilane Copolymer, 3-Methacryloyloxypropylmethyldimethoxysilane-Tetraethoxysilane Copolymer, 3-Methacryloyloxypropylmethyldiethoxysilane-Tetramethoxysilane Copolymer and 3-Methacryloyloxypropylmethyldiethoxysilane-Tetraethoxysilane Copolymer 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetramethoxy Silane Copolymer, 3-Acryloyloxypropyltriethoxysilane-Tetraethoxysilane Copolymer, 3-Acryloyloxypropylmethyldimethoxysilane-Tetramethoxysilane Copolymer, 3-Acryloyloxypropylmethyldimethoxysilane-Tetraethoxysilane Copolymer, 3-Acryloyloxypropyl acryloyloxypropyl group-containing copolymers such as methyldiethoxysilane-tetramethoxysilane copolymer and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane- Tetraethoxysilane Copolymer, Vinyltriethoxysilane-Tetramethoxysilane Copolymer, Vinyltriethoxysilane-Tetraethoxysilane Copolymer, Vinylmethyldimethoxysilane-Tetramethoxysilane Copolymer, Vinylmethyldimethoxysilane-Tetraethoxysilane Copolymer, Vinylmethyldiethoxysilane - vinyl group-containing copolymers such as tetramethoxysilane copolymer and vinylmethyldiethoxysilane-tetraethoxysilane copolymer; 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer; , 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxy and amino group-containing copolymers such as silane copolymers, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymers and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymers.

The silane coupling agent is terminally selected from the group consisting of vinyl, epoxy, styryl, methacryl, acryl, amino, isocyanurate, ureido, mercapto, isocyanate, carboxyl, and hydroxyl groups. and at least one alkoxysilyl group or silanol group. By appropriately selecting these functional groups, it is possible to improve the mechanical strength of the vertically aligned liquid crystal cured film, modify the surface of the vertically aligned liquid crystal cured film, and improve the adhesion between the vertically aligned liquid crystal cured film and adjacent layers. effect can be given. From the viewpoint of adhesion, the silane coupling agent is preferably a silane coupling agent having an alkoxysilyl group and another different reactive group (for example, the functional group described above). Furthermore, the silane coupling agent is preferably a silane coupling agent having an alkoxysilyl group and a polar group. When the silane coupling agent has at least one alkoxysilyl group and at least one polar group in its molecule, the vertical alignment property of the polymerizable liquid crystal compound can be more easily improved, and the effect of promoting vertical alignment can be significantly obtained. There is a tendency. Polar groups include, for example, epoxy groups, amino groups, isocyanurate groups, mercapto groups, carboxyl groups and hydroxy groups. In addition, the polar group may have an appropriate substituent or protective group in order to control the reactivity of the silane coupling agent.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 3-glycidoxypropyltri Methoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltri Methoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane and 3-glycidoxypropylethoxydimethylsilane is mentioned.

Further, commercially available silane coupling agents include, for example, KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001, KBM-1003, KBE-1003, KBM-303, KBM-402, KBM-403 , KBE-402, KBE-403, KBM-1403, KBM-502, KBM-503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBM-903, KBE-903, KBE - Silane coupling agents from Shin-Etsu Chemical Co., Ltd. such as 9103, KBM-573, KBM-575, KBM-9659, KBE-585, KBM-802, KBM-803, KBE-846, and KBE-9007 is mentioned.

When the polymerizable liquid crystal composition forming the vertically aligned liquid crystal cured film contains a nonionic silane compound, the content thereof is usually preferably with respect to 100 parts by mass of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition. is 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, still more preferably 0.1 to 3 parts by mass. When the content of the nonionic silane compound is within the above range, it is possible to effectively promote vertical alignment of the polymerizable liquid crystal compound while maintaining good applicability of the polymerizable liquid crystal composition.

When the polymerizable liquid crystal composition forming the vertically aligned liquid crystal cured film contains an ionic compound composed of non-metal atoms, the dry coating film formed from the polymerizable liquid crystal composition exhibits polymerizability due to electrostatic interaction. A vertical alignment control force is exerted on the liquid crystal compound, and the polymerizable liquid crystal compound tends to be aligned in the direction vertical to the film plane in the dried coating film. As a result, the cured liquid crystal film can be formed while maintaining the vertically aligned state of the polymerizable liquid crystal compound.

Examples of ionic compounds composed of non-metal atoms include onium salts (more specifically, quaternary ammonium salts, tertiary sulfonium salts in which the nitrogen atom has a positive charge, and phosphorus atoms in which the phosphorus atom has a positive charge). quaternary phosphonium salts, etc.). Among these onium salts, quaternary onium salts are preferred from the viewpoint of further improving the vertical alignment properties of the polymerizable liquid crystal compound, and from the viewpoint of improving availability and mass productivity, quaternary phosphonium salts or quaternary onium salts are preferred. Ammonium salts are more preferred. The onium salt may have two or more quaternary onium salt sites in the molecule, and may be an oligomer or polymer.

The molecular weight of the ionic compound composed of non-metallic atoms is preferably 100 or more and 10,000 or less. When the molecular weight is within the above range, it is easy to improve the vertical alignment property of the polymerizable liquid crystal compound while ensuring the applicability of the polymerizable liquid crystal composition. The molecular weight of the ionic compound composed of nonmetallic atoms is more preferably 5,000 or less, and still more preferably 3,000 or less.

Examples of cationic components of ionic compounds composed of nonmetallic atoms include inorganic cations and organic cations. Among them, organic cations are preferable because they hardly cause alignment defects in the polymerizable liquid crystal compound. Examples of organic cations include imidazolium cations, pyridinium cations, ammonium cations, sulfonium cations and phosphonium cations.

Ionic compounds consisting of non-metallic atoms generally have a counter anion. Examples of the anion component that serves as a counterion for the cation component include inorganic anions and organic anions. Among them, an organic anion is preferable because it hardly causes an alignment defect of the polymerizable liquid crystal compound. Note that cations and anions do not necessarily have to correspond one-to-one.

Specific examples of the anion component include the following.
chloride anion [Cl ⁻ ],
bromide anion [Br ⁻ ],
iodide anion [I ⁻ ],
tetrachloroaluminate anion [AlCl ₄ ⁻ ],
heptachlorodialuminate anion [Al ₂ Cl ₇ ⁻ ],
tetrafluoroborate anion [BF ₄ ⁻ ],
hexafluorophosphate anion [PF ₆ ⁻ ],
perchlorate anion [ClO ₄ ⁻ ],
nitrate anion [NO ₃ ⁻ ],
Acetate anion [CH ₃ COO ⁻ ],
trifluoroacetate anion [CF ₃ COO ⁻ ],
fluorosulfonate anion [FSO ₃ ⁻ ],
methanesulfonate anion [CH ₃ SO ₃ ⁻ ],
trifluoromethanesulfonate anion [CF ₃ SO ₃ ⁻ ],
p-toluenesulfonate anion [p-CH ₃ C ₆ H ₄ SO ₃ ⁻ ],
bis(fluorosulfonyl)imide anion [(FSO ₂ ) ₂ N ⁻ ],
bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ],
tris(trifluoromethanesulfonyl)methanide anion [(CF ₃ SO ₂ ) ₃ C ⁻ ],
hexafluoroarsenate anion [AsF ₆ ⁻ ],
hexafluoroantimonate anion [SbF ₆ ⁻ ],
hexafluoroniobate anion [NbF ₆ ⁻ ],
hexafluorotantalate anion [TaF ₆ ⁻ ],
dimethylphosphinate anion [(CH ₃ ) ₂ POO ⁻ ],
(poly)hydrofluorofluoride anions [F(HF) _n ⁻ ] (for example, n represents an integer of 1 to 3),
dicyanamide anion [(CN) ₂ N ⁻ ],
thiocyan anion [SCN ^- ],
perfluorobutanesulfonate anion [C ₄ F ₉ SO ₃ ⁻ ],
bis(pentafluoroethanesulfonyl)imide anion [(C ₂ F ₅ SO ₂ ) ₂ N ⁻ ],
perfluorobutanoate anion [C ₃ F ₇ COO ⁻ ], and (trifluoromethanesulfonyl)(trifluoromethanecarbonyl)imide anion [(CF ₃ SO ₂ )(CF ₃ CO)N ⁻ ].

Specific examples of the ionic compound composed of non-metallic atoms can be appropriately selected from combinations of the above cationic components and anionic components. Specific examples of the compound that is a combination of a cation component and an anion component include the following.

(pyridinium salt)
N-hexylpyridinium hexafluorophosphate,
N-octylpyridinium hexafluorophosphate,
N-methyl-4-hexylpyridinium hexafluorophosphate,
N-butyl-4-methylpyridinium hexafluorophosphate,
N-octyl-4-methylpyridinium hexafluorophosphate,
N-hexylpyridinium bis(fluorosulfonyl)imide,
N-octylpyridinium bis(fluorosulfonyl)imide,
N-methyl-4-hexylpyridinium bis(fluorosulfonyl)imide,
N-butyl-4-methylpyridinium bis(fluorosulfonyl)imide,
N-octyl-4-methylpyridinium bis(fluorosulfonyl)imide,
N-hexylpyridinium bis(trifluoromethanesulfonyl)imide,
N-octylpyridinium bis(trifluoromethanesulfonyl)imide,
N-methyl-4-hexylpyridinium bis(trifluoromethanesulfonyl)imide,
N-butyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide,
N-octyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide,
N-hexylpyridinium p-toluenesulfonate,
N-octylpyridinium p-toluenesulfonate,
N-methyl-4-hexylpyridinium p-toluenesulfonate,
N-butyl-4-methylpyridinium p-toluenesulfonate, and N-octyl-4-methylpyridinium p-toluenesulfonate.

(imidazolium salt)
1-ethyl-3-methylimidazolium hexafluorophosphate,
1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide,
1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide,
1-ethyl-3-methylimidazolium p-toluenesulfonate,
1-butyl-3-methylimidazolium methanesulfonate and the like.

(Pyrrolidinium salt)
N-butyl-N-methylpyrrolidinium hexafluorophosphate,
N-butyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide,
N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide,
N-butyl-N-methylpyrrolidinium p-toluenesulfonate and the like.

(ammonium salt)
tetrabutylammonium hexafluorophosphate,
tetrabutylammonium bis(fluorosulfonyl)imide,
tetrahexylammonium bis(fluorosulfonyl)imide,
trioctylmethylammonium bis(fluorosulfonyl)imide,
(2-hydroxyethyl)trimethylammonium bis(fluorosulfonyl)imide,
tetrabutylammonium bis(trifluoromethanesulfonyl)imide,
tetrahexylammonium bis(trifluoromethanesulfonyl)imide,
trioctylmethylammonium bis(trifluoromethanesulfonyl)imide,
(2-hydroxyethyl)trimethylammonium bis(trifluoromethanesulfonyl)imide,
tetrabutylammonium p-toluenesulfonate,
tetrahexylammonium p-toluenesulfonate,
trioctylmethylammonium p-toluenesulfonate,
(2-hydroxyethyl)trimethylammonium p-toluenesulfonate,
(2-hydroxyethyl)trimethylammonium dimethylphosphinate 1-(3-trimethoxysilylpropyl)-1,1,1-tributylammonium bis(trifluoromethanesulfonyl)imide,
1-(3-trimethoxysilylpropyl)-1,1,1-trimethylammonium bis(trifluoromethanesulfonyl)imide,
1-(3-trimethoxysilylbutyl)-1,1,1-tributylammonium bis(trifluoromethanesulfonyl)imide,
1-(3-trimethoxysilylbutyl)-1,1,1-trimethylammonium bis(trifluoromethanesulfonyl)imide,
N-{(3-triethoxysilylpropyl)carbamoyloxyethyl)}-N,N,N-trimethylammonium bis(trifluoromethanesulfonyl)imide, and N-[2-{3-(3-trimethoxysilylpropylamino )-1-oxopropoxy}ethyl]-N,N,N-trimethylammonium bis(trifluoromethanesulfonyl)imide.

(Phosphonium salt)
tributyl(2-methoxyethyl)phosphonium bis(trifluoromethanesulfonyl)imide,
tributylmethylphosphonium bis(trifluoromethanesulfonyl)imide,
1,1,1-trimethyl-1-[(trimethoxysilyl)methyl]phosphonium bis (trifluoromethanesulfonyl)imide,
1,1,1-trimethyl-1-[2-(trimethoxysilyl)ethyl]phosphonium bis(trifluoromethanesulfonyl)imide,
1,1,1-trimethyl-1-[3-(trimethoxysilyl)propyl]phosphonium bis(trifluoromethanesulfonyl)imide,
1,1,1-trimethyl-1-[4-(trimethoxysilyl)butyl]phosphonium bis(trifluoromethanesulfonyl)imide,
1,1,1-tributyl-1-[(trimethoxysilyl)methyl]phosphonium bis(trifluoromethanesulfonyl)imide,
1,1,1-tributyl-1-[2-(trimethoxysilyl)ethyl]phosphonium bis(trifluoromethanesulfonyl)imide and 1,1,1-tributyl-1-[3-(trimethoxysilyl)propyl] Phosphonium bis(trifluoromethanesulfonyl)imide.
These ionic compounds may be used alone or in combination of two or more. Among them, ionic compounds composed of phosphonium salts, pyridinium salts and ammonium salts are preferred.

From the viewpoint of further improving the vertical alignment property of the polymerizable liquid crystal compound, the ionic compound composed of nonmetallic atoms preferably has Si element and/or F element in the molecular structure of the cation site. If the ionic compound composed of nonmetallic atoms has Si element and/or F element in the molecular structure of the cationic site, the ionic compound is easily segregated on the surface of the vertically aligned liquid crystal cured film. Among them, the following ionic compounds (i) to (iii) are preferable as ionic compounds whose constituent elements are all non-metallic elements.

（イオン性化合物（ｉｉ））

（イオン性化合物（ｉｉｉ））

(Ionic compound (i))

(Ionic compound (ii))

(Ionic compound (iii))

For example, a method of treating the base material surface with a surfactant having an alkyl group with a relatively long chain length to improve the orientation of the liquid crystal (published by Co., Ltd.), etc.) can be applied to further improve the vertical alignment of the polymerizable liquid crystal compound. That is, by treating the base material surface with an ionic compound having an alkyl group with a relatively long chain length, the vertical orientation of the polymerizable liquid crystal compound can be effectively improved.

Specifically, it is preferable that the ionic compound composed of nonmetallic atoms satisfies the following formula (3).
5<M<16 (3)
In formula (3), M is represented by the following formula (4).
M = (Number of covalent bonds from the positively charged atom to the molecular chain end of the substituent with the largest number of covalent bonds to the molecular chain end among the substituents directly bonded to the positively charged atom ) ÷ (number of atoms with positive charge) (4)
When the ionic compound composed of non-metallic atoms satisfies the above (3), the vertical alignment property of the polymerizable liquid crystal compound can be effectively improved.

In addition, when two or more atoms with a positive charge exist in the molecule of an ionic compound composed of non-metallic atoms, the positive charge considered as a base point for a substituent having two or more atoms with a positive charge The number of covalent bonds from the atom having a to another nearest positively charged atom is the “number of covalent bonds from the positively charged atom to the end of the molecular chain” described in the definition of M above. When the ionic compound composed of nonmetallic atoms is an oligomer or polymer having two or more repeating units, the above M is calculated considering the constituent unit as one molecule. When a positively charged atom is incorporated into a ring structure, the number of covalent bonds through the ring structure to the same positively charged atom, or to the end of a substituent attached to the ring structure. Among the number of covalent bonds, the one with the larger number of covalent bonds is defined as "the number of covalent bonds from the positively charged atom to the end of the molecular chain" described in the definition of M above.

When the polymerizable liquid crystal composition forming the vertically aligned liquid crystal cured film contains an ionic compound composed of non-metallic atoms, the content thereof is usually based on 100 parts by mass of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition. It is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, even more preferably 0.1 to 3 parts by mass. When the content of the ionic compound composed of nonmetallic atoms is within the above range, it is possible to effectively promote vertical alignment of the polymerizable liquid crystal compound while maintaining good applicability of the polymerizable liquid crystal composition. can.

The polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film contains both a nonionic silane compound and an ionic compound composed of a non-metal atom, so that the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film In the formed dry coating film, the vertical alignment of the polymerizable liquid crystal compound is further promoted by the electrostatic interaction derived from the ionic compound composed of non-metallic atoms and the surface tension reduction effect derived from the nonionic silane compound. easier to be Thereby, the cured liquid crystal film can be formed while the polymerizable liquid crystal compound is maintained in a vertically aligned state with higher accuracy.

The vertically aligned liquid crystal cured film is a cured product of a polymerizable liquid crystal composition containing the vertical alignment accelerator and at least one polymerizable liquid crystal compound, preferably a polymerizable liquid crystal compound having at least one radically polymerizable group. is a cured liquid crystal film obtained by curing in a state in which is oriented perpendicular to the in-plane direction of the cured liquid crystal film. In the present invention, the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition forming the vertically aligned liquid crystal cured film means a liquid crystal compound having a polymerizable group, particularly a liquid crystal compound having at least one radically polymerizable group. preferable. The polymerizable liquid crystal compound is not particularly limited, and for example, conventionally known polymerizable liquid crystal compounds in the field of retardation films can be used.

A polymerizable group is a group that can participate in a polymerization reaction by an active radical generated from a polymerization initiator, an acid, or the like. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Among them, a radically polymerizable group is preferred, an acryloyloxy group, a methacryloyloxy group, a vinyl group and a vinyloxy group are more preferred, and an acryloyloxy group and a methacryloyloxy group are even more preferred. When the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film are laminated via the horizontal alignment film, both the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film are polymerizable having at least one radically polymerizable group. In the case of a cured product of a liquid crystal compound, the adhesion between the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film that are continuously formed through the horizontal photo-alignment film formed from a polymer having a (meth)acryloyl group. Easy to improve.

The liquid crystallinity exhibited by the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, but the thermotropic liquid crystal is preferable because it enables precise film thickness control. The phase-ordered structure of the thermotropic liquid crystal may be nematic liquid crystal or smectic liquid crystal. A polymerizable liquid crystal compound can be used individually or in combination of 2 or more types.

The polymerizable liquid crystal compound generally includes a polymerizable liquid crystal compound that exhibits normal wavelength dispersion and a polymerizable liquid crystal compound that exhibits reverse wavelength dispersion, and it is also possible to use only one type of polymerizable liquid crystal compound. Alternatively, both kinds of polymerizable liquid crystal compounds can be mixed and used. From the viewpoint that the effect of suppressing the oblique reflection hue during black display when the vertically aligned liquid crystal cured film is applied to a display device is large, it is preferable that the cured film contains a polymerizable liquid crystal compound exhibiting reverse wavelength dispersion.

The polymerizable liquid crystal compound exhibiting reverse wavelength dispersion is preferably a compound having the following characteristics (A) to (D).
(A) A compound capable of forming a nematic phase or a smectic phase.
(B) The polymerizable liquid crystal compound has π electrons along the longitudinal direction (a).
(C) It has π electrons in a direction crossing the major axis direction (a) [intersecting direction (b)].
(D) A polymerizable liquid crystal compound defined by the following formula (i), where N (πa) is the sum of π electrons present in the major axis direction (a), and N (Aa) is the sum of the molecular weights present in the major axis direction. π electron density in the long axis direction (a) of
D(πa)=N(πa)/N(Aa) (i)
and a polymerizable liquid crystal compound defined by the following formula (ii), where N(πb) is the sum of π electrons present in the cross direction (b), and N(Ab) is the sum of the molecular weights present in the cross direction (b). π electron density in the cross direction (b) of
D(πb)=N(πb)/N(Ab) (ii)
is the formula (iii)
0≦[D(πa)/D(πb)]<1 (iii)
[that is, the π electron density in the cross direction (b) is higher than the π electron density in the long axis direction (a)]. Further, as described above, a polymerizable liquid crystal compound having π electrons on the long axis and in the direction crossing it has, for example, a T-shaped structure.

In the features (A) to (D) above, the major axis direction (a) and the number of π electrons N are defined as follows.
- The long axis direction (a) is, for example, the long axis direction of a rod-like structure in the case of a compound having a rod-like structure.
- The number of π electrons N (πa) present in the major axis direction (a) does not include π electrons that disappear due to the polymerization reaction.
The number of π electrons N (πa) present along the long axis direction (a) is the total number of π electrons on the long axis and π electrons conjugated therewith, for example, present along the long axis direction (a) It includes the number of π electrons present in a ring that satisfies Hückel's rule.
- The number of π electrons N (πb) existing in the cross direction (b) does not include π electrons that disappear due to the polymerization reaction.
A polymerizable liquid crystal compound satisfying the above has a mesogenic structure in the major axis direction. A liquid crystal phase (nematic phase, smectic phase) is expressed by this mesogenic structure.

Forming a nematic phase or a smectic phase by applying a polymerizable liquid crystal compound that satisfies the above (A) to (D) onto a film (layer) that forms a liquid crystal cured film and heating it to a phase transition temperature or higher. is possible. In the nematic phase or smectic phase formed by aligning the polymerizable liquid crystal compound, the long axis directions of the polymerizable liquid crystal compound are usually oriented parallel to each other, and the long axis direction is the alignment direction of the nematic phase. becomes. When such a polymerizable liquid crystal compound is made into a film and polymerized in a nematic phase or smectic phase, a polymer film composed of a polymer oriented in the major axis direction (a) can be formed. . This polymer film absorbs ultraviolet rays by π electrons in the long axis direction (a) and π electrons in the cross direction (b). Let λbmax be the absorption maximum wavelength of ultraviolet rays absorbed by π electrons in the cross direction (b). λbmax is typically between 300 nm and 400 nm. The density of π electrons satisfies the above formula (iii), and the π electron density in the cross direction (b) is higher than the π electron density in the major axis direction (a). is greater than the absorption of linearly polarized UV light (wavelength: λbmax) having a plane of vibration in the major axis direction (a). The ratio (absorbance in cross direction (b) of linearly polarized ultraviolet rays/absorbance in long axis direction (a)) is, for example, more than 1.0, preferably 1.2 or more, usually 30 or less, for example 10 or less. is.

Polymerizable liquid crystal compounds having the above properties generally exhibit reverse wavelength dispersion in many cases. Specific examples thereof include compounds represented by the following formula (X).

In formula (X), Ar represents a divalent group having an optionally substituted aromatic group. The aromatic group as used herein refers to a ring structure having [4n+2] number of π electrons according to Hückel's rule, and is exemplified by (Ar-1) to (Ar-23) described later. You may have two or more such Ar groups via a divalent linking group. Here n represents an integer. In the case where a ring structure is formed by including heteroatoms such as -N= and -S-, the non-covalently bonded electron pairs on these heteroatoms satisfy Hückel's rule and have aromaticity. At least one or more of a nitrogen atom, an oxygen atom and a sulfur atom are preferably contained in the aromatic group. The number of aromatic groups contained in the divalent group Ar may be one, or two or more. When there is one aromatic group, the divalent group Ar may be an optionally substituted divalent aromatic group. When the number of aromatic groups contained in the divalent group Ar is two or more, the two or more aromatic groups are bonded to each other with a divalent linking group such as a single bond, -CO-O-, -O-. may be
G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a carbon may be substituted with an alkoxy group, a cyano group or a nitro group having a number of 1 to 4, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group are an oxygen atom or a sulfur atom; Alternatively, it may be substituted with a nitrogen atom.
L ¹ , L ² , B ¹ and B ² are each independently a single bond or a divalent linking group.
k and l each independently represents an integer of 0 to 3 and satisfies the relationship 1≦k+l. Here, when 2≦k+l, B ¹ and B ² and G ¹ and G ² may be the same or different from each other.
E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, wherein an alkanediyl group having 4 to 12 carbon atoms is more preferred. A hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and —CH ₂ — contained in the alkanediyl group is —O—, —S—, —SiH ₂ —, —C It may be substituted with (=O)-.
P ¹ and P ² independently represent a polymerizable group or a hydrogen atom, at least one of which is a polymerizable group.

G ¹ and G ² are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms. , a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably 1 substituted with a methyl group ,4-phenylenediyl group, unsubstituted 1,4-phenylenediyl group or unsubstituted 1,4-trans-cyclohexanediyl group, particularly preferably unsubstituted 1,4-phenylenediyl group or unsubstituted It is a substituted 1,4-trans-cyclohexanediyl group.
At least one of G ¹ and G ² present in plurality is preferably a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ² is more preferably a divalent alicyclic hydrocarbon group.

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

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

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

Polymerizable groups represented by P ¹ or P ² include epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group and oxiranyl group. , and oxetanyl groups. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyl group and a vinyloxy group are preferred, and an acryloyloxy group and a methacryloyloxy group are more preferred.

Ar preferably has at least one selected from an optionally substituted aromatic hydrocarbon ring, an optionally substituted aromatic heterocyclic ring, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include benzene ring, naphthalene ring, anthracene ring and the like, with benzene ring and naphthalene ring being preferred. Examples of the aromatic heterocyclic ring include furan ring, benzofuran ring, pyrrole ring, indole ring, thiophene ring, benzothiophene ring, pyridine ring, pyrazine ring, pyrimidine ring, triazole ring, triazine ring, pyrroline ring, imidazole ring, and pyrazole ring. , thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, and phenanthroline ring. Among them, it preferably has a thiazole ring, a benzothiazole ring, or a benzofuran ring, and more preferably has a benzothiazole group. Moreover, when a nitrogen atom is contained in Ar, the nitrogen atom preferably has a π electron.

In formula (X), the total number _Nπ of π electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, still more preferably 14 or more, and particularly It is preferably 16 or more. Also, it is preferably 30 or less, more preferably 26 or less, and still more preferably 24 or less.

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

In formulas (Ar-1) to (Ar-23), * represents a linking moiety, and Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, or an alkyl having 1 to 12 carbon atoms. a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, alkylthio group having 1 to 12 carbon atoms, N-alkylamino group having 1 to 12 carbon atoms, N,N-dialkylamino group having 2 to 12 carbon atoms, N-alkylsulfamoyl group having 1 to 12 carbon atoms or carbon represents an N,N-dialkylsulfamoyl group of numbers 2 to 12; Moreover, Z ⁰ , Z ¹ and Z ² may contain a polymerizable group.

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

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

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

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

Examples of the aromatic hydrocarbon group for Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group and biphenyl group. , is preferably a naphthyl group, more preferably a phenyl group. The aromatic heterocyclic group includes a C4-20 group containing at least one heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group. An aromatic heterocyclic group can be mentioned, and a furyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group are preferable.

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

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

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

Among formulas (Ar-1) to (Ar-23), formulas (Ar-6) and (Ar-7) are preferable from the viewpoint of molecular stability.

In formulas (Ar-16) to (Ar-23), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is attached and Z ⁰ . Examples of the aromatic heterocyclic group include those described above as the aromatic heterocyclic ring that Ar may have, and examples thereof include pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrazine ring, pyrimidine ring, and indole. ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring and the like. This aromatic heterocyclic group may have a substituent. Y ¹ , together with the nitrogen atom and Z ⁰ to which it is attached, may be the aforementioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group. Examples include benzofuran ring, benzothiazole ring, benzoxazole ring and the like.

Further, as the polymerizable liquid crystal compound for forming the vertically aligned liquid crystal cured film in the present invention, for example, a compound containing a group represented by the following formula (Y) (hereinafter also referred to as "polymerizable liquid crystal compound (Y)") is used. may be used. The polymerizable liquid crystal compound (Y) generally tends to exhibit positive wavelength dispersion. A polymerizable liquid crystal compound can be used individually or in combination of 2 or more types.

P11-B11-E11-B12-A11-B13- (Y)
[In formula (Y), P11 represents a polymerizable group.
A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a nitro group. A hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.
B11 is -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR ¹⁶ -, -NR ¹⁶ -CO-, -CO-, - represents CS- or a single bond. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
B12 and B13 each independently represent -C≡C-, -CH=CH-, -CH ₂ -CH ₂ -, -O-, -S-, -C(=O)-, -C(=O ) -O-, -O-C(=O)-, -O-C(=O)-O-, -CH=N-, -N=CH-, -N=N-, -C(=O ) -NR ¹⁶ -, -NR ¹⁶ -C(=O)-, -OCH ₂ -, -OCF ₂ -, -CH ₂ O-, -CF ₂ O-, -CH=CH-C(=O)- represents O-, -OC(=O)-CH=CH- or a single bond;
E11 represents an alkanediyl group having 1 to 12 carbon atoms, the hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and the hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. -CH ₂ - constituting the alkanediyl group may be replaced with -O- or -CO-. ]

The number of carbon atoms in the aromatic hydrocarbon group and alicyclic hydrocarbon group of A11 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, particularly 5 or 6. preferable. A11 is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

E11 is preferably a linear alkanediyl group having 1 to 12 carbon atoms. —CH ₂ — constituting the alkanediyl group may be replaced with —O—.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane -1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group and dodecane-1,12- Linear alkanediyl groups having 1 to 12 carbon atoms such as diyl groups; -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O- CH ₂ -CH ₂ - and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ - and the like.
B11 is preferably -O-, -S-, -CO-O- or -O-CO-, and more preferably -CO-O-.
B12 and B13 each independently represent -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, -OC (=O)-O- is preferred, and -O- or -OC(=O)-O- is more preferred.

［式（Ｐ－１１）～（Ｐ－１５）中、
Ｒ^１７～Ｒ^２１はそれぞれ独立に、炭素数１～６のアルキル基または水素原子を表わす。］ As the polymerizable group represented by P11, a radically polymerizable group or a cationically polymerizable group is preferable in terms of high polymerization reactivity, particularly photopolymerization reactivity, and handling is easy, and the production of the liquid crystal compound itself is also easy. Therefore, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15).

[In the formulas (P-11) to (P-15),
R ¹⁷ to R ²¹ each independently represent an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. ]

Specific examples of the groups represented by formulas (P-11) to (P-15) include groups represented by the following formulas (P-16) to (P-20).

P11 is preferably a group represented by formulas (P-14) to (P-20), more preferably a vinyl group, a p-stilbene group, an epoxy group or an oxetanyl group.
More preferably, the group represented by P11-B11- is an acryloyloxy group or a methacryloyloxy group.

Examples of the polymerizable liquid crystal compound (Y) include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI).
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III)
P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV)
P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V)
P11-B11-E11-B12-A11-B13-A12-F11 (VI)
(In the formula,
A12 to A14 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, and E12 is synonymous with E11.
F11 is a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group; (—SO ₃ H), a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom, and —CH ₂ — constituting the alkyl group and the alkoxy group may be replaced with —O— good. )

Specific examples of the polymerizable liquid crystal compound (Y) are described in "3.8.6 Network (completely crosslinked type)" in Liquid Crystal Handbook (Liquid Crystal Handbook Editing Committee, published by Maruzen Co., Ltd. on October 30, 2000). , Compounds having a polymerizable group among the compounds described in "6.5.1 Liquid crystal material b. Polymerizable nematic liquid crystal material", JP 2010-31223, JP 2010-270108, JP Polymerizable liquid crystals described in JP-A-2011-6360 and JP-A-2011-207765 can be mentioned.

Specific examples of the polymerizable liquid crystal compound (Y) include the following formulas (I-1) to (I-4), formulas (II-1) to (II-4), formulas (III-1) to formula (III-26), formulas (IV-1) to (IV-26), formulas (V-1) to (V-2) and formulas (VI-1) to (VI-6) compound. In the following formula, k1 and k2 each independently represent an integer of 2-12. These polymerizable liquid crystal compounds (Y) are preferable in terms of ease of synthesis or availability.

By using a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity, a vertically aligned liquid crystal cured film with a high degree of alignment order can be formed. In the present invention, when a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity is used as the polymerizable liquid crystal compound forming the cured film of the vertically aligned liquid crystal, the polymerizable liquid crystal compound has a high degree of order from the viewpoint of realizing a higher degree of alignment order. A smectic phase (higher-order smectic liquid crystal state) is more preferred. Here, the higher order smectic phase includes smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase and smectic L phase. Among these, smectic B phase, smectic F phase and smectic I phase are more preferable. Thermotropic liquid crystals or lyotropic liquid crystals may be used as liquid crystals, but thermotropic liquid crystals are preferred because they allow precise film thickness control. Further, the polymerizable liquid crystal compound exhibiting smectic liquid crystallinity may be a monomer, but may be an oligomer or polymer in which a polymerizable group is polymerized.

A polymerizable liquid crystal compound exhibiting smectic liquid crystallinity is a liquid crystal compound having at least one polymerizable group, and from the viewpoint of improving heat resistance of a vertically aligned liquid crystal cured film, a liquid crystal compound having two or more polymerizable groups. is preferred. Examples of the polymerizable group include (meth)acryloyloxy, vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, oxiranyl, and oxetanyl groups. is easy, the heat resistance of the vertically aligned liquid crystal cured film is easy to improve, the adhesion of the vertically aligned liquid crystal cured film and the horizontal alignment film formed from a polymer having a (meth) acryloyl group, and further the horizontal alignment It is preferable to contain a (meth)acryloyloxy group because it is easy to adjust and improve the adhesiveness with the horizontally aligned liquid crystal cured film through the film.

Polymerizable liquid crystal compounds exhibiting smectic liquid crystallinity include, for example, compounds represented by the following formula (Z) (hereinafter sometimes referred to as “polymerizable liquid crystal compound (Z)”).
U ^1z -V ^1z -W ^1z -(X ^1z -Y ^1z -) _nz -X ^2z -W ^2z -V ^2z -U ^2z (Z)
[In formula (Z), X ^1z and X ^2z independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein the divalent aromatic group or divalent A hydrogen atom contained in a valent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group. group, and carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. However, at least one of X ^1z and X ^2z is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group.
Y ^1z is a single bond or a divalent linking group.
nz is 1 to 3, and when nz is 2 or more, a plurality of X ^1z may be the same or different. X ^2z may be the same as or different from any or all of a plurality of X ^1z . Also, when nz is 2 or more, the plurality of Y ^1z may be the same or different. From the viewpoint of liquid crystallinity, nz is preferably 2 or more.
U ^1z represents a hydrogen atom or a (meth)acryloyloxy group.
^U2z represents a polymerizable group.
W ^1z and W ^2z are independently of each other a single bond or a divalent linking group.
V ^1z and V ^2z each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, -CO-, -S- or NH- may be substituted. ]

In the polymerizable liquid crystal compound (Z), X ^1z and X ^2z are each independently preferably a 1,4-phenylene group optionally having a substituent, or a 1,4-phenylene group optionally having a substituent, or a cyclohexane-1,4-diyl group, wherein at least one of X ^1z and X ^2z is an optionally substituted 1,4-phenylene group, or a substituted cyclohexane-1,4-diyl group, preferably trans-cyclohexane-1,4-diyl group. Optionally substituted 1,4-phenylene group or optionally substituted cyclohexane-1,4-diyl group may have a methyl group, ethyl and alkyl groups having 1 to 4 carbon atoms such as butyl group, cyano group and halogen atoms such as chlorine atom and fluorine atom. It is preferably unsubstituted.

Further, the polymerizable liquid crystal compound (Z) is represented by the formula (Z1) in the formula (Z):
-(X ^1z -Y ^1z -) _nz -X ^2z - (Z1)
[In the formula, X ^1z , Y ^1z , X ^2z and nz each have the same meaning as above. ]
[hereinafter referred to as partial structure (Z1). ] has an asymmetrical structure, from the viewpoint of easily exhibiting smectic liquid crystallinity.
As the polymerizable liquid crystal compound (Z) in which the partial structure (Z1) is an asymmetric structure, for example, there is a polymerizable liquid crystal compound (Z) in which nz is 1 and one ^X1z and one ^X2z are different structures. mentioned. Also, a compound in which nz is 2, two Y ^1z have the same structure, two X ^1z have the same structure, and one X ^2z has a different structure from these two X ^1z Polymerizable liquid crystal compound (Z), X ^1z bonded to W ^1z of two X ^1z has a different structure from the other X ^1z and X ^2z , and the other X ^1z and X ^2z have the same structure A polymerizable liquid crystal compound (Z) is also included. Furthermore, a compound in which nz is 3, three Y ^1z have the same structure as each other, and any one of the three X ^1z and one X ^2z has a different structure from all the other three. liquid crystal compound (Z).

Y ^1z is -CH ₂ CH ₂ -, -CH ₂ O-, -CH ₂ CH ₂ O-, -COO-, -OCOO-, a single bond, -N=N-, -CR ^az =CR ^bz -, -C≡C-, -CR ^az =N- or -CO-NR ^az - are preferred. R ^az and R ^bz each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y ^1z is more preferably —CH ₂ CH ₂ —, —COO—, or a single bond, and when there are multiple Y ^1z , Y ^1z bonded to X ^2z is —CH ₂ CH ₂ — or CH ₂ O— is more preferred. When X ^1z and X ^2z all have the same structure, it is preferred that there are two or more Y ^1z having different binding schemes. When there are a plurality of Y ^1z having different bonding schemes, an asymmetric structure is formed, and smectic liquid crystallinity tends to occur.

U ^2z is a polymerizable group as described above. U ^1z is a hydrogen atom or a polymerizable group. Because it is easy to manufacture, it is easy to improve the heat resistance of the cured vertically aligned liquid crystal film, and it is easy to adjust and improve the adhesion between the cured vertically aligned liquid crystal film and the cured horizontally aligned liquid crystal film, the polymerizable group is ( A meth)acryloyloxy group is preferred. The polymerizable group may be in a polymerized state or in an unpolymerized state, preferably in an unpolymerized state.

The alkanediyl groups represented by V ^1z and V ^2z include methylene, ethylene, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane- 1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl and icosane-1,20-diyl groups. V ^1z and V ^2z are preferably C 2-12 alkanediyl groups, more preferably C 6-12 alkanediyl groups.

Examples of the substituent optionally possessed by the alkanediyl group include a cyano group and a halogen atom. is more preferred.

W ^1z and W ^2z are each independently preferably a single bond, —O—, —S—, —COO— or OCOO—, more preferably a single bond or —O—.

The polymerizable liquid crystal compound (Z) preferably has an asymmetric molecular structure in its molecular structure. Specifically, it is a polymerizable liquid crystal compound having the following partial structures (Aa) to (Ai). It is more preferable to have It is more preferable to have a partial structure of (Aa), (Ab) or (Ac) from the viewpoint of easily exhibiting high-order smectic liquid crystallinity. In (Aa) to (Ai) below, * represents a bond (single bond).

Specific examples of the polymerizable liquid crystal compound (Z) include compounds represented by formulas (A-1) to (A-25). When the polymerizable liquid crystal compound (Z) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans form.

Among these, formula (A-2), formula (A-3), formula (A-4), formula (A-5), formula (A-6), formula (A-7), formula (A- 8), at least one selected from the group consisting of compounds represented by formula (A-13), formula (A-14), formula (A-15), formula (A-16) and formula (A-17) Seeds are preferred. As the polymerizable liquid crystal compound (Z), one type may be used alone, or two or more types may be used in combination.

The polymerizable liquid crystal compound (Z) is described, for example, in Lub et al., Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or a known method described in Japanese Patent No. 4,719,156.

In the present invention, the vertically aligned liquid crystal cured film preferably has at least one absorption maximum between 300 and 400 nm wavelength, and the polymerizable liquid crystal compound forming the vertically aligned liquid crystal cured film has a maximum absorption between 300 and 400 nm wavelength. A polymerizable liquid crystal compound having an absorption wavelength is preferred. When the polymerizable liquid crystal composition contains a photopolymerization initiator, the polymerization reaction and gelation of the polymerizable liquid crystal compound may proceed during long-term storage. However, if the maximum absorption wavelength of the polymerizable liquid crystal compound is 300 to 400 nm, even if it is exposed to ultraviolet light during storage, the generation of reactive species from the photopolymerization initiator and the production of the polymerizable liquid crystal compound by the reactive species. It can effectively suppress the progress of the polymerization reaction and gelation. Therefore, it is advantageous in terms of the long-term stability of the polymerizable liquid crystal composition, and the orientation and thickness uniformity of the obtained liquid crystal cured film can be improved. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured in a solvent using an ultraviolet-visible spectrophotometer. The solvent is a solvent capable of dissolving the polymerizable liquid crystal compound, and examples thereof include chloroform.

In a laminate in which a vertically aligned liquid crystal cured film and a horizontally aligned liquid crystal cured film are bonded with an adhesive layer, from the viewpoint of thinning the laminate and improving flexibility, a pressure sensitive adhesive is used. Energy ray-curable pressure-sensitive adhesives are considered advantageous in comparison. However, when the vertically aligned liquid crystal cured film is formed from a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having a maximum absorption wavelength in the wavelength range of 300 to 400 nm, formation of a laminate containing the vertically aligned liquid crystal cured film In , since the vertically aligned liquid crystal cured film exhibits absorption in the above wavelength range, an ultraviolet curable adhesive that cures with light (ultraviolet light) in the above wavelength range is used to cure the vertically aligned liquid crystal cured film by horizontally aligned liquid crystal curing. It is difficult to laminate other layers such as films with high adhesion. INDUSTRIAL APPLICABILITY The present invention can continuously form a vertically aligned liquid crystal cured film and a horizontally aligned liquid crystal cured film without an adhesive layer interposed therebetween. Polymerizable liquid crystal compounds that exhibit so-called reverse wavelength dispersion, which often have maximum absorption in the wavelength range of 300 to 400 nm, can be used in the structure of the laminate without causing the above-mentioned problems related to properties. It is also advantageous in that a thin laminate having optical properties can be obtained.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition forming the vertically aligned liquid crystal cured film is, for example, 70 to 99.5 parts by mass with respect to 100 parts by mass of the solid content of the polymerizable liquid crystal composition, It is preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, still more preferably 90 to 95 parts by mass. When the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the orientation of the cured liquid crystal film to be obtained. In the present invention, the solid content of the polymerizable liquid crystal composition means all components excluding volatile components such as organic solvents from the polymerizable liquid crystal composition.

The polymerizable liquid crystal composition used for forming the vertically aligned liquid crystal cured film contains additives such as a solvent, a polymerization initiator, a leveling agent, an antioxidant, and a photosensitizer in addition to a vertical alignment accelerator and a polymerizable liquid crystal compound. may further include Each of these components may be used alone or in combination of two or more.

Since the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film is usually applied to a substrate or the like in a state of being dissolved in a solvent, it preferably contains a solvent. As the solvent, a solvent capable of dissolving the polymerizable liquid crystal compound is preferable, and a solvent inert to the polymerization reaction of the polymerizable liquid crystal compound is preferable. Examples of solvents include water, alcohols such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol and propylene glycol monomethyl ether. Solvent; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone ketone solvents; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone (NMP) and 1,3-dimethyl-2-imidazolidinone; be done. These solvents can be used alone or in combination of two or more. Among these, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide solvents and aromatic hydrocarbon solvents are preferred.

The content of the solvent in the polymerizable liquid crystal composition is preferably 50 to 98 parts by weight, more preferably 70 to 95 parts by weight, per 100 parts by weight of the polymerizable liquid crystal composition. Therefore, the solid content in 100 parts by mass of the polymerizable liquid crystal composition is preferably 2 to 50 parts by mass. When the solid content is 50 parts by mass or less, the viscosity of the polymerizable liquid crystal composition is low, so that the thickness of the film becomes substantially uniform and unevenness tends to be less likely to occur. The solid content can be appropriately determined in consideration of the thickness of the cured liquid crystal film to be produced.

A polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal compound or the like by generating reactive species with the contribution of heat or light. Reactive species include active species such as radicals or cations or anions. Among them, a photopolymerization initiator that generates radicals by light irradiation is preferable from the viewpoint that reaction control is easy.

Examples of photopolymerization initiators include benzoin compounds, benzophenone compounds, benzyl ketal compounds, α-hydroxyketone compounds, α-aminoketone compounds, oxime compounds, triazine compounds, iodonium salts and sulfonium salts. Specifically, Irgacure (registered trademark) 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369, Irgacure 379, Irgacure 127, Irgacure 2959, Irgacure 754, Irgacure 379EG (above, BASF Japan Corporation ), Seikuol BZ, Seikuol Z, Seikuol BEE (manufactured by Seiko Chemical Co., Ltd.), Kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow), Adeka Optomer SP- 152, Adeka Optomer SP-170, Adeka Optomer N-1717, Adeka Optomer N-1919, Adeka Arkles NCI-831, Adeka Arkles NCI-930 (manufactured by ADEKA Co., Ltd.), TAZ-A, TAZ -PP (manufactured by Nihon SiberHegner Co., Ltd.) and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.).

Since the photopolymerization initiator can fully utilize the energy emitted from the light source and is excellent in productivity, it is preferable that the maximum absorption wavelength is 300 nm to 400 nm, more preferably 300 nm to 380 nm. Polymerization initiators and oxime photopolymerization initiators are preferred.

α-Acetophenone compounds include 2-methyl-2-morpholino-1-(4-methylsulfanylphenyl)propan-1-one, 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutane-1 -one and 2-dimethylamino-1-(4-morpholinophenyl)-2-(4-methylphenylmethyl)butan-1-one and the like, more preferably 2-methyl-2-morpholino-1-( 4-methylsulfanylphenyl)propan-1-one and 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutan-1-one. Commercially available α-acetophenone compounds include Irgacure 369, 379EG, and 907 (manufactured by BASF Japan Ltd.) and Seikuol BEE (manufactured by Seiko Kagaku Co., Ltd.).

Oxime-based photopolymerization initiators generate radicals such as phenyl radicals and methyl radicals when irradiated with light. Polymerization of the polymerizable liquid crystal compound favorably proceeds by these radicals, and among them, an oxime-based photopolymerization initiator that generates methyl radicals is preferable because of its high initiation efficiency of the polymerization reaction. Moreover, from the viewpoint of allowing the polymerization reaction to proceed more efficiently, it is preferable to use a photopolymerization initiator capable of efficiently utilizing ultraviolet rays having a wavelength of 350 nm or more. As a photopolymerization initiator capable of efficiently utilizing ultraviolet light having a wavelength of 350 nm or more, a triazine compound or a carbazole compound containing an oxime structure is preferable, and a carbazole compound containing an oxime ester structure is more preferable from the viewpoint of sensitivity. Carbazole compounds containing an oxime structure include 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methyl benzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) and the like. Commercially available oxime ester photopolymerization initiators include Irgacure OXE-01, Irgacure OXE-02, Irgacure OXE-03 (manufactured by BASF Japan Ltd.), Adeka Optomer N-1919, and Adeka Arkles NCI-831. (above, manufactured by ADEKA Corporation) and the like.

The content of the photopolymerization initiator is usually 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. is. Within the above range, the reaction of the polymerizable group proceeds sufficiently and the orientation of the polymerizable liquid crystal compound is less likely to be disturbed.

A leveling agent is an additive that has the function of adjusting the fluidity of the polymerizable liquid crystal composition and making the coating film obtained by coating the composition more flat. A fluoroalkyl-based leveling agent can be used. Commercially available products may be used as the leveling agent. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Dow Corning Toray Co., Ltd.). , KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, T SF4452, TSF4460 (all manufactured by Momentive Performance Materials Japan LLC), fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Co., Ltd.) ), Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F- 477, F-479, F-482, F-483, F-556 (all manufactured by DIC Corporation), F-top (trade name) EF301, EF303, EF351, EF352 ( All of the above are manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd.), Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40 , SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.), trade names E1830, E5844 (manufactured by Daikin Fine Chemicals Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (both trade names: manufactured by BM Chemie) and the like. A leveling agent can be used individually or in combination of 2 or more types.

The content of the leveling agent is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, it is preferable because the polymerizable liquid crystal compound can be easily oriented and the resulting cured liquid crystal film tends to be smoother.

By adding an antioxidant, the polymerization reaction of the polymerizable liquid crystal compound can be controlled. The antioxidant may be a primary antioxidant selected from phenolic antioxidants, amine antioxidants, quinone antioxidants, and nitroso antioxidants; It may be a secondary antioxidant selected from system antioxidants. In order to polymerize the polymerizable liquid crystal compound without disturbing the alignment of the polymerizable liquid crystal compound, the content of the antioxidant is usually 0.01 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. Yes, preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass. An antioxidant can be used individually or in combination of 2 or more types.

Moreover, a photoinitiator can be made highly sensitive by using a photosensitizer. Examples of photosensitizers include xanthones such as xanthone and thioxanthone; anthracenes having substituents such as anthracene and alkyl ether; phenothiazine; and rubrene. A photosensitizer can be used individually or in combination of 2 or more types. The content of the photosensitizer is usually 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. 3 parts by mass.

The polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film is prepared by mixing a vertical alignment accelerator, a polymerizable liquid crystal compound, and components other than the vertical alignment accelerator and the polymerizable liquid crystal compound, such as a solvent and a photopolymerization initiator, at a predetermined temperature. It can be obtained by stirring with

In the present invention, the vertically aligned liquid crystal cured film preferably satisfies the following formula (2).
RthC(450)/RthC(550)≤1 (2)
[In formula (2), RthC(450) represents the retardation value in the film thickness direction of the vertically aligned liquid crystal cured film at a wavelength of 450 nm, and RthC(550) is the position in the film thickness direction of the vertically aligned liquid crystal cured film at a wavelength of 550 nm. Represents the phase difference value. ]
By satisfying the above formula (2), it is possible to suppress the decrease in ellipticity on the short wavelength side in the laminate containing the vertically aligned liquid crystal cured film, and the black when the vertically aligned liquid crystal cured film is applied to the display device. It is possible to improve the oblique reflection hue during display. The value of RthC(450)/RthC(550) in the vertically aligned liquid crystal cured film is more preferably 0.95 or less, still more preferably 0.92 or less, and particularly preferably 0.9 or less. is 0.7 or more, more preferably 0.75 or more, and still more preferably 0.8 or more.

The thickness direction retardation value RthC(λ) of the vertically aligned liquid crystal cured film can be adjusted by the thickness dC of the vertically aligned liquid crystal cured film. The in-plane retardation value is given by the following formula:
RthC(λ)=((nxC(λ)+nyC(λ))/2−nzC(λ))×dC
(Wherein, nxC(λ) is the in-plane principal refractive index of the vertically aligned liquid crystal cured film at the wavelength λnm, nyC(λ) is the refraction in the plane perpendicular to nxC(λ) at the wavelength λnm index, nzC (λ) indicates the refractive index in the thickness direction of the vertically aligned liquid crystal cured film at a wavelength of λ nm, and when nxC (λ) = nyC (λ), nxC (λ) is an arbitrary refractive index in the film plane. It can be the refractive index of the direction, and dC indicates the thickness of the vertically aligned liquid crystal cured film)
Therefore, in order to obtain a desired retardation value RthC(λ) in the thickness direction, the three-dimensional refractive index and the thickness dC should be adjusted. The three-dimensional refractive index depends on the molecular structure and alignment state of the polymerizable liquid crystal compound described above.

Further, in the present invention, the vertically aligned liquid crystal cured film is preferably aligned with a high degree of order in the vertical direction of the liquid crystal cured film. In the vertically aligned liquid crystal cured film, the polymerizable liquid crystal compound is oriented with a high degree of order. It tends to be excellent in the effect of suppressing reflection hue change. The vertically aligned liquid crystal cured film satisfies the following formula (5), which represents the high alignment state of the polymerizable liquid crystal compound in the vertically aligned liquid crystal cured film, and is an indicator of the degree of the oblique optical compensation effect during black display. preferable.
−120 nm≦RthC(550)≦−30 nm (5)
In formula (5), RthC(550) has the same meaning as above. From the viewpoint of further improving the oblique reflection hue during black display, the film thickness direction retardation value RthC(550) of the vertically aligned liquid crystal cured film is more preferably −100 nm or more, more preferably −90 nm or more, and particularly It is preferably −80 nm or more, more preferably −40 nm or less, and still more preferably −50 nm or less.

[Horizontal alignment liquid crystal cured film]
The horizontally aligned liquid crystal cured film constituting the laminate of the present invention is a cured product of a polymerizable liquid crystal composition cured in a state in which the polymerizable liquid crystal compound is aligned in the horizontal direction with respect to the plane of the liquid crystal cured film, and is preferably 3. A cured liquid crystal film obtained by curing a polymerizable liquid crystal compound having at least one radically polymerizable group while oriented horizontally with respect to the in-plane direction of the cured liquid crystal film. In the present invention, the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition for forming the horizontally aligned liquid crystal cured film means a liquid crystal compound having a polymerizable group, particularly a liquid crystal compound having at least one radically polymerizable group. preferable. When the horizontally aligned liquid crystal cured film is laminated on the vertically aligned liquid crystal cured film via a horizontal photo-alignment film formed of a polymer having a (meth)acryloyl group, the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film is a cured product of a polymerizable liquid crystal compound having at least one radically polymerizable group, the adhesiveness between the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film continuously formed through the horizontal alignment film is improved. It's easy to do. In particular, since the adhesiveness between the horizontally aligned liquid crystal cured film and the vertically aligned liquid crystal cured film tends to increase, the polymerizable liquid crystal compound constituting the horizontally aligned liquid crystal cured film and the polymerizable liquid crystal compound constituting the vertically aligned liquid crystal cured film It is preferable to have a polymerizable group similar to or the same as that of the polymer that forms the horizontal alignment film together, and both the horizontal alignment liquid crystal cured film and the vertical alignment liquid crystal cured film have a (meth) acryloyl group. More preferably, it is composed of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound.

The polymerizable liquid crystal compound constituting the horizontally aligned liquid crystal cured film is not particularly limited, and for example, conventionally known polymerizable liquid crystal compounds in the field of retardation films can be used. Specifically, compounds represented by the formulas (X), (Y) or (Z) exemplified as polymerizable liquid crystal compounds that can be used for forming a vertically aligned liquid crystal cured film can be used. A polymerizable liquid crystal compound exhibiting wavelength dispersion is preferred, and for example, a compound represented by the above formula (X) can be preferably used. In the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film, the polymerizable liquid crystal compounds may be used alone or in combination of two or more.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition used for forming the horizontally aligned liquid crystal cured film is, for example, 70 to 99.5 parts by mass with respect to 100 parts by mass of the solid content of the polymerizable liquid crystal composition. , preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, still more preferably 90 to 95 parts by mass. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the orientation of the resulting cured liquid crystal film.

In addition to the polymerizable liquid crystal compound, the polymerizable liquid crystal composition used for forming the horizontally aligned liquid crystal cured film further contains additives such as a solvent, a polymerization initiator, a leveling agent, an antioxidant, and a photosensitizer. good too. Examples of these components include those exemplified above as components that can be used in the vertically aligned liquid crystal cured film, and each may be used alone or in combination of two or more. .

A polymerizable liquid crystal composition for forming a cured film of a horizontally aligned liquid crystal can be obtained by stirring a polymerizable liquid crystal compound and components other than the polymerizable liquid crystal compound, such as a solvent and a photopolymerization initiator, at a predetermined temperature. .

In addition, in the present invention, for the same reason that it is advantageous when the vertically aligned liquid crystal cured film has at least one maximum absorption in the wavelength range of 300 to 400 nm, the horizontally aligned liquid crystal cured film has a wavelength range of 300 to 400 nm. It is preferred to have at least one absorption maximum in between. In a preferred embodiment of the present invention, both the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film have at least one maximum absorption between wavelengths of 300 to 400 nm.

In the present invention, the horizontally aligned liquid crystal cured film preferably satisfies the following formula (1).
ReA(450)/ReA(550)≤1 (1)
[In the formula (1), ReA (λ) represents the in-plane retardation value of the horizontally aligned liquid crystal cured film at a wavelength λ nm, ReA (λ) = (nxA (λ) - nyA (λ)) × dA ( In the formula, nxA(λ) represents the principal refractive index at a wavelength λnm in the plane of the horizontally aligned liquid crystal cured film, and nyA(λ) is the wavelength λnm in the direction perpendicular to the direction of nxA in the same plane as nxA. and dA indicates the film thickness of the horizontally aligned liquid crystal cured film)]

When the horizontally aligned liquid crystal cured film satisfies the formula (1), the horizontally aligned liquid crystal cured film has an in-plane retardation value at a short wavelength smaller than an in-plane retardation value at a long wavelength, so-called reverse wavelength dispersion show gender. By combining such a horizontally aligned liquid crystal cured film with the above vertically aligned liquid crystal cured film, it is possible to obtain a laminate having an excellent effect of improving frontal and oblique reflection hues during black display when incorporated in an organic EL display device. can. ReA(450)/ReA(550) is preferably 0.70 or more, more preferably 0.70 or more, because the reverse wavelength dispersion is improved and the effect of improving the reflection hue in the front direction of the horizontally aligned liquid crystal cured film can be further enhanced. is 0.78 or more, preferably 0.95 or less, more preferably 0.92 or less.

The in-plane retardation value can be adjusted by the thickness dA of the horizontally aligned liquid crystal cured film. Since the in-plane retardation value is determined by the above formula ReA (λ) = (nxA (λ) - nyA (λ)) x dA, the desired in-plane retardation value (ReA (λ): wavelength λ ( In order to obtain the in-plane retardation value of the horizontally aligned liquid crystal cured film in nm), the three-dimensional refractive index and the film thickness dA should be adjusted.

Moreover, it is preferable that the horizontally aligned liquid crystal cured film satisfies the following formula (6).
120 nm≦ReA(550)≦170 nm (6)
[In formula (6), ReA (λ) has the same meaning as above]
When the in-plane retardation ReA(550) of the horizontally aligned liquid crystal cured film is within the range of formula (6), the laminate (elliptically polarizing plate) containing the horizontally aligned liquid crystal cured film is applied to an organic EL display device. The effect of improving the front reflection hue during black display becomes remarkable. A more preferable range of the in-plane retardation value is 130 nm≦ReA(550)≦150 nm.

[Horizontal Alignment Film]
The horizontal alignment film constituting the laminate of the present invention is a photo-alignment film formed from a polymer having a (meth)acryloyl group. The horizontal alignment film has a horizontal alignment control force for aligning the polymerizable liquid crystal compound in the horizontal direction with respect to the plane of the coating film. The alignment regulation force can be arbitrarily adjusted by the type of alignment film, surface condition, rubbing conditions, etc. In the case of a photo-alignment film formed from a photo-orientable polymer, it can be arbitrarily adjusted by polarized irradiation conditions. Is possible. In the present invention, a vertically aligned liquid crystal cured film is formed on a substrate, a horizontally aligned film is formed thereon, and a horizontally aligned liquid crystal cured film is formed thereon. Orientation tends to deteriorate. Although the reason is not clear, additives such as leveling agents contained in the vertically aligned liquid crystal cured film lower the surface energy, and the orientation of the liquid crystal compound is likely to be impaired when the horizontally aligned liquid crystal cured film is formed on the upper layer. It is estimated to be. In particular, when a vertically aligned liquid crystal cured film is formed without a vertical alignment film, the alignment accelerator is further included, so the effect becomes more pronounced. For this reason, the liquid crystal orientation at the time of forming the vertically aligned liquid crystal cured film is likely to be affected by the type and thickness of the horizontal alignment film.

When the horizontal alignment film has a polymerizable group similar to or the same as the polymerizable liquid crystal compound constituting the cured vertically aligned liquid crystal film and the cured horizontally aligned liquid crystal film, the cured vertically aligned liquid crystal film and the horizontally aligned liquid crystal are formed through the horizontally aligned film. Since the adhesion with the cured film tends to be higher, the horizontal alignment film is formed from a polymer having a (meth)acryloyl group, and both the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film have a (meth)acryloyl group. It is preferably formed from a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound.

A photo-alignment film is usually formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter also referred to as a “composition for forming a photo-alignment film”) to a substrate, and removing the solvent and then polarizing the film. (preferably polarized UV). The photo-alignment film is also advantageous in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light.

A photoreactive group refers to a group that exhibits liquid crystal alignment ability upon irradiation with light. Specific examples include groups involved in photoreactions that cause liquid crystal alignment ability, such as orientation induction of molecules caused by light irradiation, isomerization reactions, dimerization reactions, photocrosslinking reactions, photodecomposition reactions, and the like. Among them, a group involved in a dimerization reaction or a photocrosslinking reaction is preferable from the viewpoint of excellent orientation. As the photoreactive group, a group having an unsaturated bond, particularly a double bond is preferable, and a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond Groups having at least one selected from the group consisting of a heavy bond (N=N bond) and a carbon-oxygen double bond (C=O bond) are particularly preferred.

Photoreactive groups having a C═C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups and cinnamoyl groups. Photoreactive groups having a C═N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. The photoreactive group having an N=N bond includes an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Photoreactive groups having a C=O bond include benzophenone, coumarin, anthraquinone and maleimide groups. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

Among them, a photoreactive group that participates in a photodimerization reaction is preferable, the amount of polarized light irradiation required for photoalignment is relatively small, and a photoalignment film having excellent thermal stability and stability over time can be easily obtained. Azo, cinnamoyl and chalcone groups are preferred. As the polymer having a photoreactive group, a polymer having an azo group or a cinnamoyl group is preferable, and a polymer having a cinnamoyl group such that the end of the polymer side chain has a cinnamic acid structure is used for the horizontal alignment film and the vertically aligned liquid crystal. It is particularly preferred from the viewpoint of improving the adhesion between the cured film and the horizontally aligned liquid crystal cured film.

Examples of the solvent that can be contained in the composition for forming a photo-alignment film include the same solvents as those previously exemplified as the solvent that can be used in the polymerizable liquid crystal composition. can be selected as appropriate.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo-alignment film can be appropriately adjusted depending on the type of polymer or monomer and the thickness of the desired photo-alignment film. It is preferably at least 0.2% by mass, more preferably in the range of 0.3 to 10% by mass. The composition for forming a photo-alignment film may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer, as long as the properties of the photo-alignment film are not significantly impaired.

The thickness of the horizontal alignment film (photo-alignment film) is usually 10 to 5000 nm, preferably 100 to 1000 nm, more preferably 100 to 500 nm, even more preferably 100 to 300 nm, particularly preferably 100 to 250 nm. When the thickness of the alignment film is within the above range, the alignment film has a sufficient horizontal alignment regulating force, and cohesive failure is less likely to occur in the alignment film in the laminate.

〔Base material〕
Examples of the substrate constituting the laminate of the present invention include glass substrates and film substrates, and resin film substrates are preferable from the viewpoint of workability. Examples of resins constituting the film substrate include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; Cellulose esters such as diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalates; polycarbonates; polysulfones; polyethersulfones; polyetherketones; Such a resin can be used as a base material by forming a film by known means such as a solvent casting method and a melt extrusion method. The substrate surface may be subjected to surface treatment such as release treatment such as silicone treatment, corona treatment, plasma treatment and the like.

A commercially available product may be used as the substrate. Commercially available cellulose ester substrates include, for example, cellulose ester substrates manufactured by Fuji Photo Film Co., Ltd. such as Fujitac Film; and cellulose ester base materials. Commercially available cyclic olefin resins include, for example, cyclic olefin resins manufactured by Ticona (Germany) such as "Topas (registered trademark)"; cyclic olefins manufactured by JSR Corporation such as "Arton (registered trademark)"; Cyclic olefin resins manufactured by Nippon Zeon Co., Ltd. such as "ZEONOR (registered trademark)" and "ZEONEX (registered trademark)"; Mitsui such as "APEL" (registered trademark) A cyclic olefin-based resin manufactured by Kagaku Co., Ltd. can be mentioned. A commercially available cyclic olefin resin base material can also be used. Examples of commercially available cyclic olefin resin substrates include cyclic olefin resin substrates manufactured by Sekisui Chemical Co., Ltd. such as “Escina (registered trademark)” and “SCA40 (registered trademark)”; Optes Co., Ltd. cyclic olefin resin base material such as "; JSR Co., Ltd. cyclic olefin resin base material such as "Arton Film (registered trademark)".

In the present invention, the substrate is preferably one that can be finally peeled off from the laminate of the present invention. An elliptically polarizing plate can be obtained by bonding with a polarizing film via.

The thickness of the substrate is usually 5 to 300 μm, preferably 10 to 150 μm, from the viewpoints of thickness reduction of the laminate, easiness of peeling of the substrate, handleability of the substrate, and the like.

The laminate of the present invention may contain layers other than the substrate, the vertically aligned liquid crystal cured film, the horizontally aligned film, and the horizontally aligned liquid crystal cured film as long as the effects of the present invention are not affected. Such other layers include, for example, a cured resin layer, a hard coat layer, and a Examples include a primer layer. For example, the substrate and the vertically aligned liquid crystal cured film may be laminated via a layer having no vertical alignment control force, and the vertically aligned liquid crystal cured film and the horizontal alignment film are layers having no vertical alignment control force ( excluding the adhesive layer).

The cured resin layer can be formed from, for example, acrylic resin, methacrylic resin, epoxy resin, oxetane resin, urethane resin, melamine resin, or the like. By providing a cured resin layer, the solvent resistance of the substrate is improved, and even if the vertically aligned liquid crystal cured film formed adjacent to the cured resin layer is thin, the cured resin layer can be used as a protective layer or a reinforcing layer. It is possible to sufficiently supplement the strength of the vertically aligned liquid crystal cured film.

When the laminate of the present invention contains other layers such as the cured resin layer, the thickness of such other layers may be appropriately determined depending on the purpose and type of the layer to be provided, but is preferably 0.1 to 10 .0 μm, more preferably 0.3 to 5.0 μm.

[Method for manufacturing laminate]
The laminate of the present invention is, for example,
A step of forming a coating film of a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film containing a polymerizable liquid crystal compound, and forming a vertically aligned liquid crystal cured film from the coating film (hereinafter referred to as “vertically aligned liquid crystal cured film forming step” also called),
a step of forming a coating film of a composition for forming a horizontal alignment film, and forming a horizontal alignment film from the coating film (hereinafter also referred to as a “horizontal alignment film forming step”);
A step of forming a coating film of a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film containing a polymerizable liquid crystal compound, and forming a horizontally aligned liquid crystal cured film from the coating film (hereinafter referred to as a “horizontally aligned liquid crystal cured film forming step” also called)
It can be manufactured by a manufacturing method including in this order. When the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film are adjacent to each other in the laminate of the present invention, the vertically aligned liquid crystal cured film forming step, the horizontal alignment film forming step, and the vertically aligned liquid crystal cured film formation are performed. It is preferable that the steps are continuously performed in this order.

In the vertically aligned liquid crystal cured film forming step, the vertically aligned liquid crystal cured film is, for example,
A step of applying a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film on a substrate to obtain a coating film;
drying the coating to form a dry coating; and
It can be produced by a method including a step of irradiating a dried coating film with an active energy ray to form a vertically aligned liquid crystal cured film.

Formation of the coating film of the polymerizable liquid crystal composition is performed by, for example, forming a vertically aligned liquid crystal cured film on a base material or on another layer such as a cured resin layer provided on the base material and having no vertical alignment control force. It can be carried out by applying a polymerizable liquid crystal composition for formation.

Examples of methods for applying the polymerizable liquid crystal composition to a substrate or the like include coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods, and printing methods such as flexography. and other known methods.

Then, a dry coating film is formed by removing the solvent by drying or the like. Drying methods include natural drying, ventilation drying, heat drying, and reduced pressure drying. At this time, by heating the coating film obtained from the polymerizable liquid crystal composition, the solvent can be removed from the coating film by drying, and the polymerizable liquid crystal compound can be oriented in the direction perpendicular to the plane of the coating film. The heating temperature of the coating film can be appropriately determined in consideration of the polymerizable liquid crystal compound to be used and the material of the base material forming the coating film. A temperature above the phase transition temperature is usually required. In order to bring the polymerizable liquid crystal compound into a vertically aligned state while removing the solvent contained in the polymerizable liquid crystal composition, for example, the liquid crystal phase transition temperature (smectic phase transition temperature) of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition temperature or nematic phase transition temperature).
The liquid crystal phase transition temperature can be measured using, for example, a polarizing microscope equipped with a temperature control stage, a differential scanning calorimeter (DSC), a thermogravimetric differential thermal analyzer (TG-DTA), or the like. Further, when two or more kinds of polymerizable liquid crystal compounds are used in combination, the phase transition temperature is obtained by polymerization in which all the polymerizable liquid crystal compounds constituting the polymerizable liquid crystal composition are mixed in the same ratio as the composition in the polymerizable liquid crystal composition. It means a temperature measured using a mixture of polymerizable liquid crystal compounds in the same manner as in the case of using one type of polymerizable liquid crystal compound. It is generally known that the liquid crystal phase transition temperature of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition may be lower than the liquid crystal phase transition temperature of the polymerizable liquid crystal compound itself.

The heating time can be appropriately determined according to the heating temperature, the type of polymerizable liquid crystal compound used, the type of solvent, its boiling point and its amount, etc., but it is usually 15 seconds to 10 minutes, preferably 0.5 to 10 minutes. Five minutes.

The removal of the solvent from the coating film may be carried out simultaneously with the heating of the polymerizable liquid crystal compound to the liquid crystal phase transition temperature or higher, or may be carried out separately. Before heating to the liquid crystal phase transition temperature or higher of the polymerizable liquid crystal compound, the solvent in the coating film is moderately added under conditions in which the polymerizable liquid crystal compound contained in the coating film obtained from the polymerizable liquid crystal composition is not polymerized. A pre-drying step may be provided for removal. Examples of the drying method in the preliminary drying step include a natural drying method, a ventilation drying method, a heat drying method and a reduced pressure drying method, and the drying temperature (heating temperature) in the drying step depends on the type of polymerizable liquid crystal compound used, the can be determined as appropriate according to the type of , its boiling point, its amount, and the like.

Next, in the obtained dried coating film, the polymerizable liquid crystal compound is polymerized while maintaining the vertical alignment state of the polymerizable liquid crystal compound, thereby forming a vertically aligned liquid crystal cured film. Examples of the polymerization method include a thermal polymerization method and a photopolymerization method, and the photopolymerization method is preferable from the viewpoint of easy control of the polymerization reaction. In photopolymerization, the light irradiated to the dry coating film includes the type of polymerization initiator contained in the dry coating film, the type of polymerizable liquid crystal compound (especially the type of polymerizable group possessed by the polymerizable liquid crystal compound), and It is appropriately selected according to the amount. Specific examples thereof include at least one kind of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays and γ-rays, and active electron beams. Among them, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that a widely used photopolymerization apparatus in the field can be used. It is preferable to select the types of the polymerizable liquid crystal compound and the polymerization initiator contained in the polymerizable liquid crystal composition. The polymerization temperature can also be controlled by light irradiation while cooling the dry coating film with an appropriate cooling means at the time of polymerization. By adopting such a cooling means and polymerizing the polymerizable liquid crystal compound at a lower temperature, a vertically aligned liquid crystal cured film can be properly formed even if a base material having relatively low heat resistance is used. It is also possible to accelerate the polymerization reaction by raising the polymerization temperature within a range in which problems caused by heat during light irradiation (such as deformation of the base material due to heat) do not occur. A patterned cured film can also be obtained by performing masking or development during the photopolymerization.

Examples of the light source of the active energy ray include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and wavelength ranges. LED light sources, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc., which emit light in the range of 380 to 440 nm can be used.

The UV irradiation intensity is usually 10 to 3,000 mW/cm ² . The ultraviolet irradiation intensity is preferably in the wavelength range effective for activation of the photopolymerization initiator. The light irradiation time is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, still more preferably 0.1 seconds to 1 minute. be. When irradiated once or multiple times with such an irradiation intensity of ultraviolet rays, the cumulative amount of light is 10 to 3,000 mJ/cm ² , preferably 50 to 2,000 mJ/cm ² , more preferably 100 to 1,000 mJ/cm. ² .

The thickness of the vertically aligned liquid crystal cured film can be appropriately selected according to the display device to which it is applied, and is preferably 0.2 to 3 μm, more preferably 0.2 to 2 μm. When the vertically aligned liquid crystal cured film has forward wavelength dispersion, it is more preferably 0.2 to 1 μm, and when it has reverse wavelength dispersion, it is more preferably 0.4 to 2 μm.

In the horizontal alignment film forming step, the photo-alignment film is obtained, for example, by applying a composition for forming a photo-alignment film on the vertically aligned liquid crystal cured film, and irradiating polarized light (preferably polarized UV) after removing the solvent. be done.

The method of applying the composition for forming a photo-alignment film onto the cured film of vertically aligned liquid crystal includes the same method as the method of applying the polymerizable liquid crystal composition for forming a cured film of vertically aligned liquid crystal onto a substrate or the like. Examples of methods for removing the solvent from the coated composition for forming a photo-alignment film include natural drying, ventilation drying, heat drying, and vacuum drying.

In order to irradiate polarized light, polarized UV is irradiated directly to the coating film of the composition for forming a photo-alignment film from which the solvent has been removed. , may be of a form in which polarized light is transmitted and irradiated. Moreover, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb the light energy. Specifically, UV (ultraviolet rays) with a wavelength in the range of 250 to 400 nm is particularly preferred. Examples of the light source used for the polarized irradiation include a xenon lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, and an ultraviolet light laser such as KrF and ArF. preferable. Among these, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and a metal halide lamp are preferable because of their high emission intensity of ultraviolet rays having a wavelength of 313 nm. Polarized UV can be emitted by passing the light from the light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thompson or Glan-Taylor, or a wire grid type polarizer can be used.
A plurality of regions (patterns) having different liquid crystal alignment directions can be formed by masking the polarized light.

In the horizontally aligned liquid crystal cured film forming step, the horizontally aligned liquid crystal cured film is, for example,
obtaining a coating film by applying a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film on the horizontally aligned film;
drying the coating to form a dry coating; and
It can be produced by a method including a step of irradiating a dried coating film with an active energy ray to form a horizontally aligned liquid crystal cured film.

The coating film of the polymerizable liquid crystal composition can be formed, for example, by applying the polymerizable liquid crystal composition for forming the cured film of the horizontally aligned liquid crystal on the horizontal alignment film. Examples of the method for applying the polymerizable liquid crystal composition include the same methods as those that can be employed in the method for producing a vertically aligned liquid crystal cured film.

Then, a dry coating film is formed by removing the solvent by drying or the like. Drying methods include natural drying, ventilation drying, heat drying, and reduced pressure drying. From the viewpoint of productivity, drying by heating is preferable, and the heating temperature in that case is preferably equal to or higher than the phase transition temperature of the polymerizable liquid crystal compound and the solvent can be removed. Procedures and conditions in such steps are the same as those that can be employed in the method for producing a vertically aligned liquid crystal cured film.

The obtained dried coating film is irradiated with an active energy ray (more specifically, ultraviolet rays, etc.), and the polymerizable liquid crystal compound is irradiated while maintaining the state in which the polymerizable liquid crystal compound is aligned in the horizontal direction with respect to the plane of the coating film. is polymerized to form a horizontally aligned liquid crystal cured film. Examples of the polymerization method include the same methods as those that can be employed in the method for producing a vertically aligned liquid crystal cured film.

The thickness of the horizontally aligned liquid crystal cured film can be appropriately selected according to the display device to be applied, and is preferably 0.2 to 5 μm, more preferably 0.2 to 4 μm, and still more preferably 0.2 to 3 μm. .

In the present invention, the vertically aligned liquid crystal cured film is formed from a polymerizable liquid crystal composition containing a vertical alignment accelerator, whereby a vertically aligned liquid crystal cured film with no or few alignment defects can be obtained without using a vertical alignment film. . The laminate of the present invention, which includes such a vertically aligned liquid crystal cured film in combination with a horizontally aligned liquid crystal cured film, tends to have excellent optical properties. Excellent effect of suppressing change in reflection hue. Moreover, since a step of forming a vertical alignment film is not required, it is advantageous in terms of production efficiency and production cost.

[Elliptical polarizing plate]
The present invention includes an elliptically polarizing plate comprising the laminate of the present invention and a polarizing film.
A polarizing film is a film having a polarizing function, and includes a stretched film to which a dye having anisotropic absorption is adsorbed, a film including a film coated with a dye having anisotropic absorption as a polarizer, and the like. Dyes having absorption anisotropy include, for example, dichroic dyes.

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

A polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. Polyvinyl acetate-based resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate with other monomers copolymerizable therewith. Other monomers copolymerizable with vinyl acetate include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

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

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

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing with a dichroic dye, simultaneously with dyeing, or after dyeing. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. It is also possible to carry out uniaxial stretching in these multiple stages. In the uniaxial stretching, the film may be uniaxially stretched between rolls having different circumferential speeds, or may be uniaxially stretched using hot rolls. The uniaxial stretching may be dry stretching in which the film is stretched in the atmosphere, or may be wet stretching in which the polyvinyl alcohol resin film is stretched in a swollen state using a solvent. The draw ratio is usually about 3 to 8 times.

Dyeing a polyvinyl alcohol resin film with a dichroic dye is performed, for example, by immersing the polyvinyl alcohol resin film in an aqueous solution containing a dichroic dye.

Specifically, iodine and dichroic organic dyes are used as dichroic dyes. Dichroic organic dyes include C.I. I. Examples include dichroic direct dyes composed of disazo compounds such as DIRECT RED 39, and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo. The polyvinyl alcohol-based resin film is preferably immersed in water before dyeing.

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

On the other hand, when a dichroic organic dye is used as the dichroic dye, a method of dyeing by immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic organic dye in this aqueous solution is usually about 1×10 ⁻⁴ to 10 parts by weight, preferably 1×10 ⁻³ to 1 part by weight, more preferably about 1×10 −3 to 1 part by weight, per 100 parts by weight of water. is 1×10 ⁻³ to 1×10 ⁻² parts by mass. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80°C. The immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

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

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

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

The thickness of the polarizer obtained by subjecting the polyvinyl alcohol resin film to uniaxial stretching, dyeing with a dichroic dye, boric acid treatment, washing with water and drying is preferably 5 to 40 μm.

Examples of the film coated with a dye having anisotropic absorption include a film obtained by coating a composition containing a dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a polymerizable liquid crystal. mentioned. The film preferably has a protective film on one or both sides thereof. Examples of the protective film include the same resin films as the base material that can be used in the production of the vertically aligned liquid crystal cured film.

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

Specific examples of the film coated with a dye having absorption anisotropy include films described in JP-A-2012-33249.

A transparent protective film may be laminated on at least one surface of the polarizer thus obtained, for example, via an adhesive layer. As the transparent protective film, the same transparent film as the resin film exemplified above as the base material that can be used in the production of the vertically aligned liquid crystal cured film can be used.

The elliptically polarizing plate of the present invention comprises the laminate of the present invention, or a laminate obtained by removing the substrate from the laminate of the present invention and a polarizing film. and a polarizing film via an adhesive layer or the like, the elliptically polarizing plate of the present invention can be obtained. Further, the elliptically polarizing plate of the present invention can be obtained by laminating the laminate obtained by removing the base material from the laminate of the present invention and a polarizing film.

In one embodiment of the present invention, when the laminate of the present invention and a polarizing film are laminated, the slow axis (optical axis) of the horizontally aligned liquid crystal cured film constituting the laminate and the absorption axis of the polarizing film It is preferable to laminate so that the angle formed is 45±5°.

The elliptically polarizing plate of the present invention may have a structure like a conventional general elliptically polarizing plate, or a polarizing film and a retardation film. As such a configuration, for example, an adhesive layer (sheet) for bonding an elliptically polarizing plate to a display element such as an organic EL or the like, a polarizing film or a liquid crystal cured film used for the purpose of protecting the surface from scratches and stains protection film, etc.

The laminate and elliptically polarizing plate of the present invention can be used in various display devices.
A display device is a device having a display element, and includes a light-emitting element or a light-emitting device as a light source. Examples of display devices include liquid crystal displays, organic electroluminescence (EL) displays, inorganic electroluminescence (EL) displays, touch panel displays, electron emission displays (e.g. field emission displays (FED), surface field emission displays). (SED)), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (e.g. grating light valve (GLV) display device, display device having digital micromirror device (DMD) ) and piezoelectric ceramic displays, etc. Liquid crystal display devices include transmissive liquid crystal display devices, semi-transmissive liquid crystal display devices, reflective liquid crystal display devices, direct view liquid crystal display devices, projection liquid crystal display devices, and the like. The display device may be a display device for displaying a two-dimensional image or a stereoscopic display device for displaying a three-dimensional image.In particular, the elliptically polarizing plate of the present invention has It can be suitably used for organic electroluminescence (EL) display devices because it is likely to be exhibited remarkably, and the laminate of the present invention can be suitably used for liquid crystal display devices and touch panel display devices. By using an elliptically polarizing plate, it is possible to obtain a display device that is easy to realize a thin display device, has excellent optical characteristics, and can exhibit good image display characteristics.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples. Unless otherwise specified, "%" and "parts" in the examples mean % by mass and parts by mass, respectively.

1. Example 1
(1) Preparation of Composition for Forming Horizontal Alignment Film A mixture obtained by mixing 5 parts by mass of a photo-alignment material having the following structure (weight average molecular weight: 30000) and 95 parts by mass of cyclopentanone (solvent) as components. was stirred at 80° C. for 1 hour to obtain a composition for forming a horizontal alignment film.

(2) Preparation of Polymerizable Liquid Crystal Compounds A polymerizable liquid crystal compound (X1) and a polymerizable liquid crystal compound (X2) having the following molecular structures were prepared. Polymerizable liquid crystal compound (X1) was produced according to the method described in JP-A-2010-31223. Further, the polymerizable liquid crystal compound (X2) was produced according to the method described in JP-A-2009-173893.

Polymerizable liquid crystal compound (X1)

Polymerizable liquid crystal compound (X2)

A solution was obtained by dissolving 1 mg of the polymerizable liquid crystal compound (X1) in 50 mL of tetrahydrofuran. The solution obtained as a measurement sample is placed in a measurement cell with an optical path length of 1 cm, and the measurement sample is set in an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation "UV-2450") to measure the absorption spectrum. When the wavelength at which the maximum absorbance was obtained was read from the obtained absorption spectrum, the maximum absorption wavelength λ _max in the wavelength range of 300 to 400 nm was 350 nm.

(3) Preparation of a polymerizable liquid crystal composition for forming a cured film of a horizontally aligned liquid crystal A polymerizable liquid crystal compound LC242 represented by the following formula (LC242): Paliocolor LC242 (registered trademark of BASF) is added to a leveling agent (manufactured by DIC "F- 556") and 3 parts by weight of a polymerization initiator Irg369 were added. Furthermore, cyclopentanone was added so that the solid content concentration was 13%, and these were mixed to obtain a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film.

LC242: Paliocolor LC242 (registered trademark of BASF)

(4) Preparation of polymerizable liquid crystal composition for forming cured film of vertically aligned liquid crystal Liquid crystal compound (X2) 100 parts by weight, leveling agent "F-556" (manufactured by DIC) 0.25 parts by weight, Patent application 2016 Ionic compound A prepared with reference to JP-514802 (molecular weight: 645) 2.0 parts by weight, silane coupling agent "KBE-9103" (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight, photopolymerization As an initiator, 6 parts by mass of 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one ("Irgacure (registered trademark) 369 (Irg369)" manufactured by BASF Japan Ltd.) was added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%. The mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film.

Ionic compound A:

(5) Preparation of base material Dipentaerythritol hexaacrylate (Aronix M-403 polyfunctional acrylate manufactured by Toagosei Co., Ltd.) 50 parts by mass, acrylate resin (Ebecryl 4858 manufactured by Daicel UCB Co., Ltd.) 50 parts by mass, 2-methyl- 1[4-(methylthio)phenyl]-2-morifolinopropan-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) 3 parts by weight dissolved in 250 parts by weight of isopropanol to prepare a solution containing an acrylate compound. A composition for forming a cured resin layer was obtained.
Subsequently, a TAC film (KC4UY) manufactured by Konica Minolta, Inc. was coated with the composition for forming a cured resin layer with a bar coater and dried at 50° C. for 1 minute. After that, using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Inc.), the cured resin is irradiated with ultraviolet rays (in a nitrogen atmosphere, integrated light intensity at a wavelength of 365 nm: 400 mJ/cm ² ). formed a layer. The film thickness of the obtained cured resin layer was measured with a contact film thickness gauge and found to be 2.0 μm. At this time, using "KOBRA-WPR" manufactured by Oji Scientific Instruments Co., Ltd., after measuring the retardation value Re550 of the laminate of the TAC film and the cured resin layer, when the retardation value Re550 derived from the TAC film was subtracted, It was confirmed that the retardation value was 3 nm or less and was optically isotropic.

(6) Preparation of vertically aligned liquid crystal cured film On the cured resin layer on the base material prepared as described above, a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film was applied using a bar coater, and heated at 120 ° C. for 60 minutes. heated for seconds. Then, while being heated to 120 ° C., using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.), ultraviolet rays from the surface coated with the polymerizable liquid crystal composition for forming a cured film of vertically aligned liquid crystal (in a nitrogen atmosphere, integrated light intensity at a wavelength of 365 nm: 500 mJ/cm ² ) to form a vertically aligned liquid crystal cured film, and the substrate, the cured resin layer, and the vertically aligned liquid crystal cured film are laminated adjacently in this order. A laminated body was obtained. The film thickness of the obtained vertically aligned liquid crystal cured film was measured with an ellipsometer (M-220 manufactured by JASCO Corporation) and found to be 0.6 μm.

<Measurement of retardation value of vertically aligned liquid crystal cured film>
Corona treatment was performed on the surface of the vertically aligned liquid crystal cured film of the laminate composed of the base material, the cured resin layer, and the vertically aligned liquid crystal cured film prepared by the above procedure, and it was attached to the glass via a 25 μm pressure-sensitive adhesive manufactured by Lintec. After combining, the TAC film and the cured resin layer were peeled off. For the obtained laminate consisting of glass, adhesive, and vertically aligned liquid crystal cured film, KOBRA-WPR manufactured by Oji Scientific Instruments Co., Ltd. was used to change the incident angle of light to the sample for optical property measurement, and the front retardation was measured. and a phase difference value when tilted at 40° about the fast axis center.
The average refractive index at each wavelength was measured using an ellipsometer M-220 manufactured by JASCO Corporation. The film thickness was measured using an Optical NanoGauge film thickness gauge C12562-01 manufactured by Hamamatsu Photonics K.K. From the values of the front retardation value, the retardation value when tilted at 40° about the fast axis, the average refractive index, and the film thickness, Oji Scientific Instruments technical data (http://www.oji-keisoku.co .jp/products/kobra/reference.html) to calculate the three-dimensional refractive index. From the obtained three-dimensional refractive index, the optical properties of the vertically aligned liquid crystal cured film are calculated according to the following formula, and the values of Rth(450), Rth(550), αth=Rth(450)/Rth(550) are calculated. did. Table 1 shows the results.
RthC(λ)=((nxC(λ)+nyC(λ))/2−nzC(λ))×dC
RthC(λ) represents the retardation value in the film thickness direction of the vertically aligned liquid crystal cured film at a wavelength of λnm. Further, nxC(λ) is the in-plane principal refractive index of the vertically aligned liquid crystal cured film at wavelength λnm, nyC(λ) is the refractive index in the direction perpendicular to nxC(λ) at wavelength λnm, and nzC( λ) indicates the refractive index in the thickness direction of the vertically aligned liquid crystal cured film at a wavelength of λ nm, and when nxC(λ)=nyC(λ), nxC(λ) is the refractive index in any direction in the film plane. and dC indicates the film thickness of the vertically aligned liquid crystal cured film.

(7) Preparation of horizontally aligned liquid crystal cured film Corona treatment was performed on the vertically aligned liquid crystal cured film surface of the laminate composed of the substrate (TAC film), the cured resin layer, and the vertically aligned liquid crystal cured film manufactured by the above method. A composition for forming a horizontal alignment film was applied using a bar coater and dried at 80° C. for 1 minute. Next, using a polarized UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Inc.), polarized UV exposure was performed at a wavelength of 313 nm with an integrated light quantity of 100 mJ/cm ² to obtain a horizontal alignment film. The film thickness of the resulting horizontal alignment film was measured with an ellipsometer and found to be 200 nm.
Subsequently, a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film was applied on the horizontal alignment film, heated at 120° C. for 60 seconds, and then a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.). to form a horizontally aligned liquid crystal cured film by irradiating the surface coated with the polymerizable liquid crystal composition for horizontally aligned liquid crystal cured film formation with ultraviolet rays (in a nitrogen atmosphere, integrated light amount at a wavelength of 365 nm: 500 mJ/cm ² ). Then, a laminate was obtained in which the substrate, the cured resin layer, the vertically aligned liquid crystal cured film, the horizontally aligned film, and the horizontally aligned liquid crystal cured film were laminated adjacently in this order. The film thickness of the resulting horizontally aligned liquid crystal cured film was measured with an ellipsometer and found to be 1.1 μm. In this laminate, the total film thickness T1 from the surface of the vertically aligned liquid crystal cured film on the substrate side to the surface of the horizontally aligned liquid crystal cured film on the side opposite to the horizontal alignment film was 1.9 μm.
The laminate obtained in Example 1 is a laminate having a structure of substrate (TAC film)/cured resin layer/cured vertically aligned liquid crystal film/horizontally aligned film/cured horizontally aligned liquid crystal film.

<Retardation value measurement of horizontally aligned liquid crystal cured film>
Corona treatment was performed on the surface of the horizontally aligned liquid crystal cured film of the laminate consisting of the base material, the cured resin layer, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film. The TAC film and the cured resin layer were peeled off after lamination to the glass via the glass. Re (450) and Re measured using KOBRA-WPR manufactured by Oji Scientific Instruments Co., Ltd. for the obtained laminate consisting of the glass, adhesive, cured vertically aligned liquid crystal film, horizontally aligned film, and cured horizontally aligned liquid crystal film. Re(450) and Re(550) of the vertically aligned liquid crystal cured film measured in advance by the method described above were subtracted from the value of (550), and ReA(450) and ReA(550) of the horizontally aligned liquid crystal cured film were obtained. was calculated, and further αA=ReA(450)/ReA(550) was calculated. Table 1 shows the results.

(8) Evaluation of laminate <Evaluation of orientation of laminate>
The laminate thus obtained was attached to glass of 5×5 cm×0.7 mm in thickness via a pressure-sensitive adhesive (25 μm) manufactured by Lintec Corporation, and only the substrate was peeled off. The resulting sample was observed using a polarizing microscope (“BX-51” manufactured by Olympus Corporation) at a magnification of 200 times, and the number of orientation defects in a field of view of 480 μm×320 μm was counted. Here, as the number of orientation defects, only the orientation defects caused by the measurement sample were counted, and the number of defects caused by environmental foreign matter other than the sample was excluded and not counted. Based on the results of observation with a polarizing microscope, the orientation of the laminate was evaluated based on the following evaluation criteria. If ◯, it was judged that the orientation was excellent, and if △, it was judged that the orientation was to the extent that the optical characteristics were not affected. Table 1 shows the results.
Evaluation criteria:
◯ (very good): The number of orientation defects is 0 or more and 5 or less.
Δ (Good): The number of orientation defects is 6 or more and 20 or less.
x (bad): 21 or more orientation defects, or no orientation at all.

<Laminate adhesion test>
The adhesion test of the laminate was carried out as follows with reference to the adhesion test (cross-cut method) of JIS K5600-5-6. First, the horizontally aligned liquid crystal cured film side of the laminate and glass of 5 × 5 cm × thickness 0.7 mm were bonded via a pressure-sensitive adhesive (25 μm) manufactured by Lintec, and only the base material was peeled off from the laminate. . 100 squares of cuts of 1 mm square were made with a cutter on the laminate side of the obtained sample. Cellotape (registered trademark) (manufactured by Nichiban Co., Ltd.) was pasted on the obtained 100 cuts, and after peeling off the cellotape, the number of squares peeled between layers in the laminate was checked, and the following criteria were used. to determine the adhesion. Table 1 shows the results.
Evaluation criteria:
◯: Less than 30 squares were peeled off between layers in the laminate after the cellophane tape was peeled off.
Δ: 30 or more and 59 or less squares were peeled off between layers in the laminate after the cellophane tape was peeled off.
x: 60 or more squares were peeled off between layers in the laminate after the cellophane tape was peeled off.

2. Example 2
In the same manner as in Example 1, except that the preparation of the polymerizable liquid crystal composition for forming the horizontally aligned liquid crystal cured film and the formation of the horizontally aligned liquid crystal cured film were changed as follows, the substrate, the cured resin layer, and the vertically aligned liquid crystal A laminate was produced by laminating a cured film, a horizontal alignment film, and a horizontally aligned liquid crystal cured film adjacently in this order, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

(1) Preparation of polymerizable liquid crystal composition for forming cured film of horizontally aligned liquid crystal The polymerizable liquid crystal compound (X1) and the polymerizable liquid crystal compound (X2) were mixed at a mass ratio of 90:10 to obtain a mixture. With respect to 100 parts by mass of the resulting mixture, 0.1 parts by mass of a leveling agent "BYK-361N" (manufactured by BM Chemie) and 2-dimethylamino-2-benzyl-1-(4- 6 parts by mass of morpholinophenyl)butan-1-one (“Irgacure (registered trademark) 369 (Irg369)” manufactured by BASF Japan) was added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%. The mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film.

(2) Formation of horizontally aligned liquid crystal cured film Corona treatment was performed on the surface of the vertically aligned liquid crystal cured film of the laminate composed of the substrate (TAC film), the cured resin layer, and the vertically aligned liquid crystal cured film prepared in the same manner as in Example 1. was applied using a bar coater and dried at 80° C. for 1 minute. Next, using a polarized UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Inc.), polarized UV exposure was performed at a wavelength of 313 nm with an integrated light quantity of 100 mJ/cm ² to obtain a horizontal alignment film. The film thickness of the resulting horizontal alignment film was measured with an ellipsometer and found to be 200 nm.
Subsequently, a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film was applied on the horizontal alignment film, heated at 120° C. for 60 seconds, and then a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.). to form a horizontally aligned liquid crystal cured film by irradiating the surface coated with the polymerizable liquid crystal composition for horizontally aligned liquid crystal cured film formation with ultraviolet rays (in a nitrogen atmosphere, integrated light amount at a wavelength of 365 nm: 500 mJ/cm ² ). Then, a laminate was obtained in which the substrate, the cured resin layer, the vertically aligned liquid crystal cured film, the horizontally aligned film, and the horizontally aligned liquid crystal cured film were laminated adjacently in this order. The film thickness of the resulting horizontally aligned liquid crystal cured film was measured with an ellipsometer and found to be 2.2 μm.

3. Example 3
In the same manner as in Example 2, except that the preparation of the polymerizable liquid crystal composition for forming the vertically aligned liquid crystal cured film and the formation of the vertically aligned liquid crystal cured film were changed as follows, the substrate, the cured resin layer, and the vertically aligned liquid crystal curing A laminate was produced by laminating the film, the horizontal alignment film, and the horizontal alignment film and the cured horizontal liquid crystal film adjacently in this order, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

(1) Preparation of polymerizable liquid crystal composition for forming cured film of vertically aligned liquid crystal The polymerizable liquid crystal compound (X1) and the polymerizable liquid crystal compound (X2) were mixed at a mass ratio of 90:10 to obtain a mixture. With respect to 100 parts by mass of the resulting mixture, 0.25 parts by mass of leveling agent "F-556" (manufactured by DIC), ionic compound A prepared with reference to Japanese Patent Application No. 2016-514802 (molecular weight: 645 ) 2.0 parts by mass, silane coupling agent "KBE-9103" (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by mass, 2-dimethylamino-2-benzyl-1-(4-morpholino as a photopolymerization initiator 6 parts by mass of phenyl)butan-1-one (“Irgacure (registered trademark) 369 (Irg369)” manufactured by BASF Japan) was added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%. The mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film.

(2) Preparation of vertically aligned liquid crystal cured film A polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film was applied onto the cured resin layer on the substrate prepared by the same procedure as in Example 1 using a bar coater. , after heating at 120 ° C. for 60 seconds, using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.), ultraviolet rays are applied from the surface coated with the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film. A vertically aligned liquid crystal cured film was formed by irradiation (accumulated light quantity at wavelength 365 nm: 500 mJ/cm ² in a nitrogen atmosphere). The film thickness of the obtained vertically aligned liquid crystal cured film was measured with an ellipsometer (M-220 manufactured by JASCO Corporation) and found to be 1.2 μm.

4. Example 4
Substrate, cured resin layer, vertically aligned liquid crystal cured film, cured resin layer, horizontal alignment film, and horizontally aligned liquid crystal cured film were prepared in the same manner as in Example 3, except that the formation of the horizontally aligned liquid crystal cured film was changed as follows. were laminated in this order, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

(1) Formation of horizontally aligned liquid crystal cured film Dipentaerythritol hexaacrylate (Aronix M-403 polyfunctional acrylate manufactured by Toagosei Co., Ltd.) 50 parts by mass, acrylate resin (Ebecryl 4858 manufactured by Daicel UCB Co., Ltd.) 50 parts by mass, 2 -Methyl-1 [4-(methylthio) phenyl] -2-morifolinopropan-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) 3 parts by weight of isopropanol 250 parts by weight to prepare a solution, acrylate A composition for forming a cured resin layer containing the compound was obtained.
Subsequently, the surface of the vertically aligned liquid crystal cured film of the laminate composed of the substrate (TAC film), the cured resin layer, and the vertically aligned liquid crystal cured film was subjected to corona treatment, and the composition for forming the cured resin layer was applied with a bar coater. , 50° C. for 1 minute. After that, using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Inc.), the cured resin is irradiated with ultraviolet rays (in a nitrogen atmosphere, an integrated amount of light at a wavelength of 365 nm: 400 mJ/cm ² ). formed a layer. The film thickness of the obtained cured resin layer was measured with a contact film thickness gauge and found to be 2.0 μm.
Next, the surface of the cured resin layer in the outermost layer of the laminate consisting of the base material (TAC film), the cured resin layer, the vertically aligned liquid crystal cured film, and the cured resin layer prepared by the above method was subjected to corona treatment, and the horizontal The alignment film-forming composition was applied using a bar coater and dried at 80° C. for 1 minute. Next, using a polarized UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Inc.), polarized UV exposure was performed at a wavelength of 313 nm with an integrated light quantity of 100 mJ/cm ² to obtain a horizontal alignment film. The film thickness of the resulting horizontal alignment film was measured with an ellipsometer and found to be 200 nm.
Subsequently, a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film was applied on the horizontal alignment film, heated at 120° C. for 60 seconds, and then a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.). to form a horizontally aligned liquid crystal cured film by irradiating the surface coated with the polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film with ultraviolet rays (in a nitrogen atmosphere, integrated light amount at a wavelength of 365 nm: 500 mJ/cm ² ). Then, a laminate was obtained in which the substrate, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film were laminated in this order adjacent to each other. The film thickness of the resulting horizontally aligned liquid crystal cured film was measured with an ellipsometer and found to be 2.2 μm.

5. Example 5
The substrate, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film are laminated in this order in the same manner as in Example 3, except that the method for producing the vertically aligned liquid crystal cured film is changed as follows. A laminated body was produced, and the adhesion and orientation of the laminated body were evaluated. Table 1 shows the results.

(1) Preparation of vertically aligned liquid crystal cured film:
A COP film (ZF14-23) manufactured by Nippon Zeon Co., Ltd. was subjected to corona treatment, then coated with a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film using a bar coater, and heated at 120° C. for 60 seconds. Then, while being heated to 120 ° C., using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.), ultraviolet rays from the surface coated with the polymerizable liquid crystal composition for forming a cured film of vertically aligned liquid crystal (in a nitrogen atmosphere, integrated light intensity at a wavelength of 365 nm: 500 mJ/cm ² ) to form a vertically aligned liquid crystal cured film, and a laminate in which the substrate and the vertically aligned liquid crystal cured film are laminated in this order adjacent to each other. Obtained. The film thickness of the obtained vertically aligned liquid crystal cured film was measured with an ellipsometer (M-220 manufactured by JASCO Corporation) and found to be 1.2 μm.

6. Example 6
In the same manner as in Example 3, except that the preparation of the substrate was changed as follows, the substrate, the cured resin layer, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film were laminated in this order adjacent to each other. A laminated body was produced, and the adhesion and orientation of the laminated body were evaluated. Table 1 shows the results.

(1) Preparation of base material Dipentaerythritol hexaacrylate (Aronix M-403 polyfunctional acrylate manufactured by Toagosei Co., Ltd.) 50 parts by mass, acrylate resin (Ebecryl 4858 manufactured by Daicel UCB Co., Ltd.) 50 parts by mass, 2-methyl- 1[4-(methylthio)phenyl]-2-morifolinopropan-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) 3 parts by weight dissolved in 250 parts by weight of isopropanol to prepare a solution containing an acrylate compound. A composition for forming a cured resin layer was obtained.
Subsequently, on a PET film (Diafoil T140E25) manufactured by Mitsubishi Plastics Co., Ltd., the composition for forming a cured resin layer was applied with a bar coater, dried at 50 ° C. for 1 minute, and then dried with a high-pressure mercury lamp ("Unicure VB-15201BY -A”, manufactured by Ushio Inc.), a cured resin layer was formed by irradiating with ultraviolet rays (in a nitrogen atmosphere, integrated light quantity at a wavelength of 365 nm: 400 mJ/cm ² ). The film thickness of the obtained cured resin layer was measured with a contact film thickness gauge and found to be 2.0 μm.

7. Example 7
A laminate in which the base material, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film are laminated in this order in the same manner as in Example 5, except that the thickness of the horizontal alignment film is changed to 30 nm. was produced, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

8. Example 8
A laminate in which the substrate, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film are laminated in this order in the same manner as in Example 5, except that the thickness of the horizontal alignment film is changed to 500 nm. was produced, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

9. Example 9
A substrate, a vertically aligned liquid crystal cured film, a horizontal alignment film, and a horizontally aligned liquid crystal cured film were prepared in the same manner as in Example 5, except that the preparation of the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film was changed as follows. A laminate was produced by laminating adjacently in this order, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

(1) Preparation of polymerizable liquid crystal composition for forming cured film of vertically aligned liquid crystal The polymerizable liquid crystal compound (X1) and the polymerizable liquid crystal compound (X2) were mixed at a mass ratio of 90:10 to obtain a mixture. With respect to 100 parts by mass of the resulting mixture, 0.25 parts by mass of leveling agent "F-556" (manufactured by DIC), ionic compound A prepared with reference to Japanese Patent Application No. 2016-514802 (molecular weight: 645 ) 2.0 parts by mass, 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one as a photopolymerization initiator (manufactured by BASF Japan Co., Ltd. “Irgacure (registered trademark) 369 (Irg369) ”) 6 parts by mass were added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%. The mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film.

10. Example 10
A substrate, a vertically aligned liquid crystal cured film, a horizontal alignment film, and a horizontally aligned liquid crystal cured film were prepared in the same manner as in Example 5, except that the preparation of the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film was changed as follows. A laminate was produced by laminating adjacently in this order, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

(1) Preparation of polymerizable liquid crystal composition for forming cured film of vertically aligned liquid crystal The polymerizable liquid crystal compound (X1) and the polymerizable liquid crystal compound (X2) were mixed at a mass ratio of 90:10 to obtain a mixture. With respect to 100 parts by mass of the obtained mixture, 0.25 parts by mass of leveling agent "F-556" (manufactured by DIC) and 0.5 mass of silane coupling agent "KBE-9103" (manufactured by Shin-Etsu Chemical Co., Ltd.) part, 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one as a photopolymerization initiator (manufactured by BASF Japan Co., Ltd. "Irgacure (registered trademark) 369 (Irg369)") 6 parts by mass was added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%. The mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film.

11. Comparative example 1
A substrate, a vertically aligned liquid crystal cured film, a horizontal alignment film, and a horizontally aligned liquid crystal cured film were prepared in the same manner as in Example 5, except that the preparation of the polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film was changed as follows. A laminate was produced by laminating adjacently in this order, and the adhesion and orientation of the laminate were evaluated. Table 1 shows the results.

(1) Preparation of polymerizable liquid crystal composition for forming cured film of vertically aligned liquid crystal The polymerizable liquid crystal compound (X1) and the polymerizable liquid crystal compound (X2) were mixed at a mass ratio of 90:10 to obtain a mixture. With respect to 100 parts by mass of the resulting mixture, 0.25 parts by mass of leveling agent "F-556" (manufactured by DIC), 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl as a photopolymerization initiator ) 6 parts by mass of butan-1-one (manufactured by BASF Japan Ltd. “Irgacure (registered trademark) 369 (Irg369)”) was added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%. The mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film.

12. Comparative example 2
In the same manner as in Example 5, except that the manufacturing process of the horizontally aligned liquid crystal cured film was changed as follows, the substrate, the vertically aligned liquid crystal cured film, the horizontally aligned film, and the horizontally aligned liquid crystal cured film were laminated adjacently in this order. A laminated body was produced, and the adhesion and orientation of the laminated body were evaluated. Table 1 shows the results.

(1) Preparation of polymerizable liquid crystal composition for forming cured film of horizontally aligned liquid crystal The polymerizable liquid crystal compound (X1) and the polymerizable liquid crystal compound (X2) were mixed at a mass ratio of 90:10 to obtain a mixture. With respect to 100 parts by mass of the resulting mixture, 0.1 parts by mass of a leveling agent "BYK-361N" (manufactured by BM Chemie) and 2-dimethylamino-2-benzyl-1-(4- 6 parts by mass of morpholinophenyl)butan-1-one (“Irgacure (registered trademark) 369 (Irg369)” manufactured by BASF Japan) was added. Furthermore, cyclopentanone was added so that the solid content concentration was 13%. The mixture was stirred at 80° C. for 1 hour to obtain a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film.

(2) Formation of Horizontally Aligned Liquid Crystal Cured Film Corona treatment was performed on the vertically aligned liquid crystal cured film of the laminate composed of the substrate and the vertically aligned liquid crystal cured film produced by the method described above. Subsequently, a 4% by mass aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was applied and dried to form a film having a thickness of 0.2 μm. Subsequently, the surface of the obtained film was subjected to rubbing treatment to obtain a horizontal alignment film. Rubbing treatment is performed using a semi-automatic rubbing device (trade name: LQ-008 type, manufactured by Joyo Engineering Co., Ltd.) with a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.) with a pushing amount of 0.15 mm. , 500 rpm and 16.7 mm/s.
Subsequently, a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film was applied on the horizontal alignment film, heated at 120° C. for 60 seconds, and then a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.). to form a horizontally aligned liquid crystal cured film by irradiating the surface coated with the polymerizable liquid crystal composition for horizontally aligned liquid crystal cured film formation with ultraviolet rays (in a nitrogen atmosphere, integrated light amount at a wavelength of 365 nm: 500 mJ/cm ² ). Then, a laminate was obtained in which the substrate, the vertically aligned liquid crystal cured film, the horizontal alignment film, and the horizontally aligned liquid crystal cured film were laminated in this order adjacent to each other. The film thickness of the resulting horizontally aligned liquid crystal cured film was measured with an ellipsometer and found to be 2.2 μm.

According to the present invention, it was confirmed that a vertically aligned liquid crystal cured film can be produced without forming a vertically aligned film, and that liquid crystal alignment and adhesion can be improved at the same time (Examples 1 to 10). On the other hand, when a polymerizable liquid crystal composition containing no vertical alignment accelerator is used, a vertically aligned liquid crystal cured film cannot be obtained without forming a vertical alignment film. The retardation value of the cured film could not be calculated (Comparative Example 1). Furthermore, in Comparative Example 2 in which the horizontal alignment film was not a photo-alignment film, the adhesiveness between the vertically aligned liquid crystal cured film and the horizontally aligned liquid crystal cured film was inferior.

1: Substrate 2: Vertical alignment liquid crystal cured film 3: Horizontal alignment film 4: Horizontal alignment liquid crystal cured film 5: Cured resin layer 11: Laminate

Claims (14)

A laminate including a substrate, a vertically aligned liquid crystal cured film, a horizontal alignment film, and a horizontally aligned liquid crystal cured film adjacent to each other in this order,
The vertically aligned liquid crystal cured film is a cured product of a polymerizable liquid crystal composition cured in a state in which a polymerizable liquid crystal compound having at least one radically polymerizable group is aligned in a direction perpendicular to the plane of the liquid crystal cured film, and the following formula (2):
RthC(450)/RthC(550)≤1 (2)
[In formula (2), RthC(450) represents the thickness direction retardation value of the vertically aligned liquid crystal cured film at a wavelength of 450 nm, and RthC(550) represents the thickness direction retardation value of the vertically aligned liquid crystal cured film at a wavelength of 550 nm. represents]
The filling,
The horizontally aligned liquid crystal cured film is a cured product of a polymerizable liquid crystal composition cured in a state in which a polymerizable liquid crystal compound having at least one radically polymerizable group is horizontally aligned with respect to the plane of the liquid crystal cured film, and the following formula (1):
ReA(450)/ReA(550)≤1 (1)
[In the formula (1), ReA (450) represents the in-plane retardation value at a wavelength of 450 nm in the in-plane direction of the horizontally aligned liquid crystal cured film, and ReA (550) represents the in-plane direction of the horizontally aligned liquid crystal cured film at a wavelength of 550 nm represents the in-plane retardation value at]
The filling,
The vertically aligned liquid crystal cured film contains a vertical alignment accelerator, a nonionic silane compound as the vertical alignment accelerator, the nonionic silane compound being a silane coupling agent,
The horizontal alignment film is a photo-alignment film formed from a polymer having a (meth)acryloyl group,
A laminate, wherein the total thickness from the substrate-side surface of the vertically aligned liquid crystal cured film to the surface of the horizontally aligned liquid crystal cured film opposite to the horizontal alignment film is 10 μm or less. 2. The laminate according to claim 1, wherein the substrate is a peelable substrate. 3. The laminate according to claim 1, wherein the horizontal alignment film has a thickness of 10 to 5000 nm. 4. The laminate according to any one of claims 1 to 3, wherein the horizontal alignment film is a photo-alignment film formed from a polymer having an azo group or a cinnamoyl group. 5. The laminate according to any one of claims 1 to 4, wherein the horizontally aligned liquid crystal cured film has at least one maximum absorption between wavelengths of 300 to 400 nm. 6. The laminate according to any one of claims 1 to 5 , wherein the vertically aligned liquid crystal cured film contains an ionic compound composed of non-metallic atoms as a vertically aligned accelerator. 7. The vertically aligned liquid crystal cured film according to any one of claims 1 to 6 , wherein the vertically aligned liquid crystal cured film contains an ionic compound composed of non-metallic atoms as a vertical alignment accelerator, and the molecular weight of the ionic compound is 100 or more and 10,000 or less. laminate. 8. The laminate according to any one of claims 1 to 7 , wherein the vertically aligned liquid crystal cured film has at least one maximum absorption between wavelengths of 300 to 400 nm. An elliptically polarizing plate comprising the laminate according to any one of claims 1 to 8 and a polarizing film. An elliptically polarizing plate comprising a laminate obtained by removing the substrate from the laminate according to any one of claims 1 to 8 , and a polarizing film. 11. The elliptically polarizing plate according to claim 9 , wherein the angle between the slow axis of the horizontally aligned liquid crystal cured film constituting the laminate and the absorption axis of the polarizing film is 45±5°. An organic EL display device comprising the elliptically polarizing plate according to any one of claims 9 to 11 . A method for manufacturing a laminate according to any one of claims 1 to 8 ,
forming a coating film of a polymerizable liquid crystal composition for forming a vertically aligned liquid crystal cured film containing a polymerizable liquid crystal compound, and forming a vertically aligned liquid crystal cured film from the coating film;
a step of forming a coating film of a composition for forming a horizontal alignment film, and forming a horizontal alignment film from the coating film;
A production method comprising the steps of forming a coating film of a polymerizable liquid crystal composition for forming a horizontally aligned liquid crystal cured film containing a polymerizable liquid crystal compound, and forming a horizontally aligned liquid crystal cured film from the coating film, in this order. 14. The manufacturing method according to claim 13 , wherein the step of forming a vertically aligned liquid crystal cured film, the step of forming a horizontal alignment film, and the step of forming a horizontally aligned liquid crystal cured film are successively performed in this order.

Images