KR20160118131A - Production method for optical compensation film - Google Patents

Abstract

An object of the present invention is to provide a method for producing an optically anisotropic film which is capable of efficiently producing an optically anisotropic film of uniform quality with uniform orientation of constituent molecules. According to the present invention, there is provided a process for coating a substrate, comprising the steps of: applying a solution containing a polymerizable liquid crystal compound onto a supporting substrate; heating the coating film obtained in the coating step to evaporate the solvent to a temperature T _H ; A cooling step of cooling the coated film to a room temperature, and a polymerization step of irradiating a coating film that has been subjected to the cooling step to light to polymerize the coating film, wherein the temperature control, particularly the cooling process, It is possible to efficiently produce an optically anisotropic film of good quality with uniform orientation of constituent molecules. Further, the present invention can be applied to the production of optically anisotropic films having excellent wavelength dispersion control characteristics.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical compensation film,

The present invention relates to a process for producing an optical compensation film, and more particularly to a process for producing an optical compensation film of good quality with uniform orientation of constituent molecules.

BACKGROUND ART Optical compensation technology using a retardation plate is known for the purpose of making a liquid crystal display (LCD) have a wide viewing angle or a high contrast. As such a retardation plate, a stretched film in which a birefringence is controlled by stretching a polymer film Is used.

In recent years, a liquid crystal compound having a polymerizable group has been utilized for an optically anisotropic film exhibiting birefringence (optical anisotropy) such as a reflection type polarizing plate and a retardation plate. This compound exhibits birefringence in a liquid crystal state, and its orientation is fixed by polymerization. The fixed orientation state of the polymer is exemplified by homogeneous, tilted, homeotropic and twisted orientations, and the like. . The retardation plate obtained by using the polymerizable liquid crystal compound exhibits a large birefringence as compared with a stretched film which has been conventionally used, so that it can be thinned and can be directly applied on a base material, so that an adhesive layer is unnecessary . Further, since it is possible to construct a solid network, it has excellent characteristics such as a small rate of change of characteristics with respect to the external environment, etc. Furthermore, since the three-dimensional refractive index can be easily controlled by the orientation control of the liquid crystal, great.

An optically anisotropic film having a homogeneous orientation can be used as a composite retardation plate or a circular polarizer plate by combining with, for example, a half-wave plate, a quarter-wave plate, or a film having another optical function 1).

An optically anisotropic film having homeotropic orientation is classified as a positive C-plate in the refractive index ellipsoid because the direction of the optical axis is the direction of the nz and the refractive index in the optical axis direction is larger than the refractive index in the orthogonal direction. This positive C-plate can be used for optical compensation such as a so-called IPS (In-Plane Switching) mode, for example, in improving the viewing angle characteristic of a polarizing plate by combining with a horizontally aligned liquid crystal mode (Non-Patent Documents 1 to 3, Patent Documents 2 and 3).

Since the optical properties required for the optically anisotropic film vary depending on the application and purpose, various liquid crystal compounds have been developed as the compounds to be used. In addition, since it is often difficult to control the above-described anisotropy alone, it is used as a liquid crystal composition in combination with various compounds.

Such a liquid crystal composition is dissolved in an organic solvent for the purpose of controlling the coating property and used as an ink. In order to produce a film having optical anisotropy using a liquid crystal composition, an ink is prepared by dissolving a liquid crystal compound, a photopolymerization initiator, a surfactant, and the like in an organic solvent to adjust solution viscosity, leveling property, and the like. This ink is applied to an oriented substrate, the solvent is dried, and the liquid crystal composition is oriented on the substrate. Next, ultraviolet light is irradiated to polymerize and the alignment state is fixed. Usually, the solvent is dried and removed, and the polymerization is carried out at room temperature until polymerization. During this period, crystals and the like must not be precipitated and a uniform liquid crystal state must be maintained. Therefore, the polymerizable compound used in the liquid crystal composition must maintain good compatibility with other liquid crystalline compounds, high solubility in organic solvents, and long-term liquid crystallinity in the vicinity of room temperature. In view of the influence on the environment and the human body, organic solvents are required to have high solubility in organic solvents having high stability.

In addition to the properties of optical anisotropy, the polymer obtained from the liquid crystal composition is also required to have high transparency, a large mechanical strength, high adhesion to substrates, low shrinkage, high heat resistance, and high chemical resistance.

In an optically anisotropic layer formed from bar-shaped molecules, usually, two refractive indices ne (anomalous refractive index in a direction parallel to the molecular long axis) and no (anisotropic refractive index in a direction perpendicular to the molecular long axis) ) Becomes smaller as the wavelength becomes larger. At this time, since the refractive index change rate of ne relative to the wavelength is greater than no, the refractive index anisotropy (? N = ne-no) becomes smaller as the applied wavelength increases. On the other hand, in a display device such as a liquid crystal display (LCD), a light source is a white light composed of light having a wavelength of about 380 to 800 nm, but a 1/2? Or 1/4? Plate is designed using a normal optical anisotropic layer When applied, the above-described wavelength dispersion causes a change in the polarization state due to the wavelength, resulting in a problem that the light becomes colored. In order to prevent this problem, it is necessary to control the wavelength dispersion property so as to have a designed retardation at each wavelength, and it is necessary to control the wavelength dispersion property of the material having low dependency of the refractive index anisotropy (low wavelength dispersion property) (Reverse wavelength dispersion characteristic) in which the refractive index anisotropy is increased.

Further, in the organic EL display (OLED), it is known to use a circularly polarizing plate composed of a quarter wave plate and a polarizer on the viewing side (viewing side) for the purpose of preventing reflection of external light (Patent Document 4). Even in such an application, the deviation of the phase difference due to the wavelength dispersion characteristic changes the polarization state. Therefore, there arises a problem that the antireflection function can not be effectively obtained with respect to the entire wavelength of the visible region. Therefore, a material having an inverse wavelength dispersion characteristic is required.

In order to obtain an optically anisotropic layer having an inverse wavelength dispersion characteristic, a method has been proposed in which two retardation layers are formed by forming an angle in the direction of refractive index anisotropy, respectively (Patent Documents 5 and 6). However, such a laminate requires two retardation layers, and it is necessary to adjust the anisotropy angles of the two retardation layers, and the manufacturing complexity for forming a laminate, and the film thickness of the optically anisotropic layer And the like.

Recently, in order to solve such a problem, an optically anisotropic layer having an inverse wavelength dispersion without lamination is required, and a liquid crystal compound having an inverse wavelength dispersion property has been proposed (Patent Documents 7 to 11).

However, since the liquid crystalline compound having the reverse wavelength dispersion property has a bulky structure in a direction perpendicular to the long axis of the molecule as compared with a conventional bar-like liquid crystal molecule, the aspect ratio is small and it is difficult to control the alignment uniformity There is a challenge.

Japanese Patent Application Laid-Open No. 2002-372623 WO 05/38517 U.S. Patent Application Publication No. 2006/182900 Japanese Patent Application Laid-Open No. 8-321381 Japanese Patent Application Laid-Open No. 10-068816 Japanese Patent Application Laid-Open No. 2001-004837 Japan Specification No. 2010-522893 Japanese Patent Application Laid-Open No. 2009-179563 International Publication No. 2012/169424 Japanese Patent Application Laid-Open No. 2010-031223 Japanese Patent Application Laid-Open No. 2014-63143

M. S. Park et al., IDW '04 FMC8-4 M. Nakata et al, SID '06 P-58 K. J. Kim et al, SID '06 Digest p.1158-1161

An object of the present invention is to provide a process for producing an optical compensation film which is capable of efficiently producing a high quality optical compensation film having uniform orientation of constituent molecules.

As a result of careful examination, the present inventors have found that the above problems can be solved by precisely controlling the temperature control, particularly the cooling process, in the production process of the optical compensation film, and have completed the invention.

That is, the present invention is as follows.

[1] A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound, a photopolymerization initiator, a surfactant, and a solvent, wherein the polymerizable liquid crystal composition is applied onto a supporting substrate, An optical anisotropic film comprising a heating step of heating the coating film to a temperature T _H , a cooling step of cooling the coating film after the heating step to room temperature, and a polymerization step of irradiating light to the coating film that has undergone the cooling step and polymerizing In the method,

Wherein the polymerizable liquid crystal compound exhibits a nematic phase and has an aspect ratio (length of long axis / short axis length) of the molecular structure of 3 or less,

Wherein the cooling step satisfies at least one of the following conditions (i) and (ii).

(i) the period of time at which the coating film is held at the temperature T _i (T _H > T _i > room temperature + 20 ° C) at least once and the time at which the coating film is maintained at the temperature T _i is 30 seconds or more .

(ii) the average cooling rate from the coating film temperature T _H to the room temperature is 20 ° C / min or less.

[2] When the phase transition temperature from the liquid crystal phase to the isotropic phase of the coating film obtained by applying the polymerizable liquid crystal composition onto a supporting substrate and evaporating the solvent is T _NI , T _H , T _i , and T _NI satisfy the following _equations is a relationship satisfying the conditions (a) and (b).

(a) T _H ≥ T _NI + 15 ° C

(b) T _H -10 ° C ≥T _i ≥ room temperature + 20 ° C

[3] The production method of an optically anisotropic film according to [1] or [2], wherein the T _H , T _i , and T _NI satisfy the following conditions (c) and (d).

(c) T _NI ≥ 45 ° C

(d) T _NI + 5 ° C ≥T _i ≥45 ° C

[4] The method for producing an optical compensation film according to any one of [1] to [3], wherein a birefringence Δn (λ) with respect to light of wavelength λ nm is Δn (450) / Δn (550) ≪ / RTI >

[5] The polymerizable liquid crystal composition according to any one of [1] to [4], wherein the polymerizable liquid crystal compound comprises at least one member selected from the group consisting of compounds represented by the following formulas (1-1) Gt; a < / RTI >

In the above formulas (1-1) to (1-4)

X ¹ , X ³ and X ⁴ are each independently -O- or -S-;

X ² is -CH = or -N =;

W ¹ is an aromatic ring which may contain a hetero atom and the aromatic ring may be a single bond or -C≡C- connected to a 5-membered ring containing X ¹ and X ² , and the number of π electrons is 6 to 16 ;

W ² is a condensed ring of oxygen, sulfur, a 5-membered ring, a 6-membered ring or a 5-membered ring and a 6-membered ring;

W ³ each independently represents cyano, alkoxycarbonyl having 1 to 10 carbon atoms or alkanoyl having 1 to 10 carbon atoms, and at least one -CH ₂ - in the alkoxycarbonyl and alkanoyl is -O-, -COO -, -OCO-, -CH = CH- or -C = C-;

W ⁴ represents a divalent linking group selected from the group consisting of -CH = CH-, -C≡C-, an aromatic ring which may contain a hetero atom or a combination thereof;

R ¹ is independently a group represented by the following formula (2-1)

In the formula (2-1), A ¹ is each independently 1,4-phenylene or 1,4-cyclohexylene. In this 1,4-phenylene, at least one hydrogen is fluorine, cyano , Formyl, trifluoroacetyl, trifluoromethyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms; Z ¹ each independently represents a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -OCH ₂ CH ₂ O-, -CH ₂ CH ₂ COO-, -OCOCH ₂ CH ₂ -, -CH ₂ CH ₂ OCO- or -COOCH ₂ CH ₂ -; m is independently an integer of 1 or 2; Y ¹ is a single bond, -O-, -COO-, -OCO- or OCOO-; Q ¹ is a single bond or alkylene having 1 to 20 carbon atoms, and at least one -CH ₂ - in the alkylene is -O-, -COO-, -OCO-, -CH = CH- or -C≡ C-; PG is a polymerizable group represented by any one of the following formulas (PG-1) to (PG-8).

In the formulas (PG-1) to (PG-8), R ³ is each independently hydrogen, halogen, methyl, ethyl or trifluoromethyl;

In the above formulas (1-1) to (1-4)

R ² is independently a group represented by the following formula (2-2)

In the formula (2-2), A ² is each independently 1,4-phenylene or 1,4-cyclohexylene, and in 1,4-phenylene, at least one hydrogen is fluorine, trifluoro Methyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms; Z ² is a single bond; n is independently an integer of 0 to 3; R ⁴ is selected from the group consisting of hydrogen, fluorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of 1 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms or alkoxycarbonyl of 1 to 20 carbon atoms to be.

[6] The compound according to the above [1], wherein Z ¹ in the formula (2-1) is independently -COO-, -OCO-, -CH ₂ CH ₂ COO- or -OCOCH ₂ CH ₂ - 1]. ≪ / RTI >

[7] The method for producing an optically anisotropic film according to [5] or [6], wherein the polymerizable liquid crystal compound is a compound represented by the formula (1-1) or (1-3).

[8] An optical element comprising an optically anisotropic film and a polarizing plate produced by the method for producing an optically anisotropic film according to any one of [1] to [7].

[9] A liquid crystal display device comprising an inner surface or an outer surface of an optically anisotropic film produced by the method for producing an optically anisotropic film according to any one of [1] to [7].

[10] An organic EL display device comprising the optical element according to [8].

According to the present invention, it is possible to efficiently produce optically anisotropic films of good quality with uniform orientation of constituent molecules. Further, the present invention can be applied to the production of optically anisotropic films having excellent wavelength dispersion control characteristics.

Fig. 1 shows the retardation measurement results of the optically anisotropic film produced in Example 1. Fig.
2 is a graph of a wavelength dispersion characteristic (a measured value of a wavelength? Nm (Re _? ) / A wavelength dependence of a measured value (Re ₅₅₀ ) of a wavelength 550 nm) of the optically anisotropic film produced in Example 1. FIG.

The usage of the terms in this specification is as follows. The term "liquid crystal compound" is a generic term of a compound having a liquid crystal phase and a compound which does not have a liquid crystal phase but is useful as a component of a liquid crystal composition. The liquid crystal phase is a nematic phase, a smectic phase, a cholesteric phase, etc. In most cases, it means a nematic phase. Polymerization means the ability of the monomer to polymerize by means of light, heat, catalyst, etc. to provide the polymer. The compound represented by the formula (1) may be referred to as the compound (1). The compounds represented by other formulas may also be referred to by the same simplification method.

The term " liquid crystalline property " is not limited to having a liquid crystal phase. Even if it does not have a liquid crystal phase in itself, the properties that can be used as components of the liquid crystal composition when mixed with other liquid crystal compounds are also included in the meaning of liquid crystallinity.

A substituent whose bonding position with carbon constituting the ring is not clear means that the bonding position is free within a range in which there is no chemical problem. The optically active compound having a polymerizable group of the present invention may be referred to as a polymerizable optically active compound, an optically active compound, or simply a compound. The polymerizable liquid crystal composition may also be referred to as a liquid crystal composition or simply as a composition. The case where the compound has one polymerizable group may be referred to as monofunctional. When the compound has a plurality of polymerizable groups, it may be referred to as a polyfunctional or a name corresponding to the number of polymerizable groups.

In the case where there is a description of the contents shown below, the straight line from A to B means a bond, the hydrogen in B is substituted with a group A, and the position is arbitrary. X represents the number of the group A to be substituted. When X is 0, A does not exist and indicates that it is not substituted.

When a group represented by the following formula (C) is present as a chemical formula, it means that the wave line portion is a bonding position as a group.

≪ Production method of optically anisotropic film >

The method for producing an optically anisotropic film (hereinafter sometimes abbreviated as " the production method of the present invention ") which is an aspect of the present invention is a method for producing an optically anisotropic film comprising a polymerizable liquid crystal compound, a photopolymerization initiator, a surfactant, a support applied to the coating on the substrate step (hereinafter, sometimes abbreviated as "applying step"), a heating process (referred to as "heating step" for heating the film obtained from the coating step in order to evaporate the solvent at a temperature T _H (Hereinafter may be abbreviated as " cooling step " in some cases), and a step of cooling the coating film after the heating step to room temperature (Hereinafter may be abbreviated as " polymerization step ").

The polymerizable liquid crystal compound is a compound having a nematic phase and an aspect ratio of the molecular structure (length / length of the long axis) of 3 or less,

Wherein the cooling step satisfies at least one of the following conditions (i) and (ii).

(i) the period of time at which the coating film is held at the temperature T _i (T _H > T _i > room temperature + 20 ° C) at least once and the time at which the coating film is maintained at the temperature T _i is 30 seconds or more .

(ii) the average cooling rate from the coating film temperature T _H to the room temperature is 20 ° C / min or less.

The present inventors have found that by controlling the cooling process in the production process of the optically anisotropic film as described in (i) or (ii) and controlling the cooling conditions, the optically anisotropic film of uniform quality, I found what I could get. This method is a relatively easily applicable method and is an excellent method for producing an optically anisotropic film of good quality without impairing productivity. In addition, this method has an advantage that it can be applied to the production of optically anisotropic films having excellent wavelength dispersion control characteristics.

The " long axis in the aspect ratio of the molecular structure (length of long axis / length of short axis) " means the length in the long side direction of the molecular model when the molecular structure is optimized, Quot; means the length in the direction perpendicular to the longitudinal direction. For the optimization of the molecular structure, a molecular calculation method is used, for example, B3LYP / 6-31G (d). In the present invention, the molecular structure was optimized by the method of B3LYP / 6-31G (d), and the aspect ratio was calculated.

Further, the expression of "maintaining at the temperature T _i " means the means used for heating the coating film or the temperature of the external environment.

The term " temperature T _i " means a specific temperature at the time of holding, and in the case where the temperature is held plural times, T ₁ , T ₂ , T ₃ , ... , T _j .

The term " room temperature " in " cooling the coating film to room temperature " or " coating film is cooled to room temperature " means that the surface temperature of the supporting substrate on which the coating film is formed is used instead, do. The " surface temperature " can be measured using a contact-type temperature sensor or the like.

The "average cooling rate until the coating film is cooled to room temperature" is a value obtained by dividing the temperature difference between the temperature T _H and the room temperature by the total time from the coating film temperature T _H to the room temperature .

(Average cooling rate) = (temperature T _H - room temperature (25 ° C)) / (total time to cooling [minute])

Hereinafter, a coating process, a heating process, a cooling process, and a polymerization process will be described, and then a polymerizable liquid crystal compound, a photopolymerization initiator, a surfactant, a solvent, and a support substrate will be described.

(Coating step)

The application step is a step of applying a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound, a photopolymerization initiator, a surfactant, and a solvent onto a support substrate. The specific application method and application conditions are not particularly limited, Or conditions can be appropriately selected. Specific examples of the coating method include a spin coating method, a micro gravure coating method, a gravure coating method, a wire bar coating method, a dipping coating method, a spray coating method, a meniscus coating method, a die coating method, etc. For example. The orientation of the polymerizable liquid crystal compound can be controlled without applying a surface treatment of the substrate by rubbing or the like by applying a wire bar coating method in which a shear stress is applied to the solution at the time of coating.

(Heating process, cooling process)

The heating step is a step of heating the coating film obtained in the coating step to evaporate the solvent at a temperature T _H , and the temperature T _H is not particularly limited as long as the solvent can be evaporated, and the polymerizable liquid crystal compound The type of the solvent, and the like.

The temperature T _H is preferably a temperature at which the polymerizable liquid crystal compound is uniformly oriented.

When the polymerizable liquid crystal composition is coated on a supporting substrate and the phase transition temperature from the liquid crystal phase to the isotropic phase of the coating film obtained by evaporating the solvent is taken as the temperature T _NI , T _H > T _NI is preferable, and T _H More preferably? T _NI + 10 ° C, and more preferably T _H ? T _NI + 15 ° C. Within the above-mentioned range, an optically anisotropic film having a uniform orientation of constituent molecules can be easily produced.

The temperature T _H is preferably 45 ° C or higher, more preferably 60 ° C or higher, more preferably 80 ° C or higher, and is preferably 200 ° C or lower, more preferably 150 ° C or lower, and even more preferably 120 ° C or lower .

The heating time at the temperature T _H is usually 5 seconds to 2 hours, preferably 10 seconds or more, more preferably 20 seconds or more, preferably 30 minutes or less, and more preferably 10 minutes or less. Within the above-mentioned range, it is easy to efficiently produce an optically anisotropic film having a uniform orientation of constituent molecules.

The heating method in the heating step is not particularly limited, and known methods and conditions can be appropriately selected. As a specific heating method, for example, a method using a hot plate, a drying furnace, a warm air / hot air jetting device, and the like can be mentioned. The heating method may be a method in which the temperature of the substrate is elevated by standing on a hot plate maintained at T _H in advance or in a high chamber such as an oven or a hot plate placed at room temperature, , and set to T _H, it may be raised from the room temperature to T _H.

The cooling step is a step of cooling the coating film that has been subjected to the heating step to room temperature, and is characterized by satisfying at least one of the following conditions (i) and (ii).

(i) the time period during which the coating film is maintained at the temperature T _i (T _H > T _i > room temperature + 20 ° C) at least once before the coating film is cooled to room temperature, and the holding time at the temperature T _i is 30 seconds or more.

(ii) the average cooling rate from the coating film temperature T _H to the room temperature is 20 ° C / min or less.

The temperature T _i is not particularly limited as long as T _H > T _i > room temperature + 20 ° C, but it is preferable that T _H -10 ° C ≥T _i ≥ room temperature + 20 ° C. Within the above-mentioned range, it becomes easy to efficiently produce an optically anisotropic film having a uniform orientation of constituent molecules.

The holding time of the temperature T _i is not particularly limited as long as it is 30 seconds or more, but is preferably 30 seconds or more, more preferably 1 minute or more, and 10 minutes or less. Within the above-mentioned range, it becomes easy to efficiently produce an optically anisotropic film having a uniform orientation of constituent molecules.

The average cooling rate from the coating film temperature T _H to the room temperature is preferably 15 ° C / minute or less.

As a specific mode (first mode) of the heating process and the cooling process, in order to obtain uniform orientation, the coating film is heated to a temperature at which the liquid crystal composition exhibits an isotropic phase (heating process) and then a temperature at which a nematic liquid crystal phase ( _Ti ), the nematic alignment is almost completed in the liquid crystal composition in the coating film, and then the temperature is lowered to room temperature (cooling step) to obtain a more orderly orientation .

The heating temperature T _H is higher than the temperature (T _NI ) which transitions from the nematic phase to the isotropic phase, and T _H ≥ T _NI + 10 ° C is preferable, and T _H ≥ T _NI + 15 ° C is more preferable. The heating time is 5 seconds to 2 hours. A preferable range of this time is 10 seconds to 30 minutes, and a more preferable range is 20 seconds to 10 minutes.

It is also preferable that the temperature T _i is T _NI + 5 ° C ≥T _i ≥45 ° C, and T _NI is a polymerizable liquid crystal composition having T _NI ≥45 ° C.

As another mode (second mode) of the heating process and the cooling process, the coating film is heated to a temperature T _NI or more at which the liquid crystal composition exhibits an isotropic phase (heating process) in order to obtain uniform orientation, similarly to the first mode , And slowly lowering the temperature to room temperature (cooling step), thereby achieving orderly alignment. The heat treatment temperature T _H is higher than the temperature (T _NI ) which transitions from the nematic phase to the isotropic phase, and T _H ≥ T _NI + 10 ° C is preferable, and T _H ≥ T _NI + 15 ° C is more preferable. The heating time is 5 seconds to 2 hours. A preferable range of this time is 10 seconds to 30 minutes, and a more preferable range is 20 seconds to 10 minutes. Heating process, beforehand to a predetermined temperature the value in the high, such as a hot plate phase or oven maintained at may raise the temperature of the substrate, and the value in the high, such as phase or a hot plate, oven binary placed in room temperature to be raised to T _H It is possible. In order to raise the temperature of the layer made of the liquid crystal composition to a predetermined temperature, the heating time is preferably 5 seconds or more. The cooling step for cooling from T _H to room temperature is carried out at a rate of 20 ° C / min or less. The cooling step may be performed by keeping the substrate in the air and cooling it, or by leaving it on a base of a material having low thermal conductivity such as rubber. In order not to lower the productivity, the heating time is preferably within 2 hours. Thus, the polymerizable liquid crystal layer of the present invention can be obtained.

(Polymerization step)

The polymerization step is a step of irradiating a coating film that has undergone the cooling step with light to polymerize the polymerizable liquid crystal compound contained therein, and the orientation of the constituent molecules is fixed by this polymerization.

The kind of light to be irradiated with light in the polymerization step is not particularly limited, and examples thereof include ultraviolet rays, visible light, and infrared rays (heat rays), but ultraviolet rays and visible rays are preferred. The specific wavelength is usually 150 nm or more, preferably 250 nm or more, more preferably 300 nm or more, and usually 500 nm or less, preferably 450 nm or less, more preferably 400 nm or less.

Examples of the light source include a low pressure mercury lamp (sterilization lamp, fluorescent chemical lamp, black light), a high pressure discharge lamp (high pressure mercury lamp, metal halide lamp), a short arc discharge lamp (ultra high pressure mercury lamp, xenon lamp, mercury xenon lamp) A metal halide lamp, a xenon lamp, an ultra high pressure mercury lamp, and a high pressure mercury lamp are preferable.

The light amount is preferably ^{2 to} 5000 mJ / cm ² , more preferably 10 mJ / cm ² or more, more preferably 100 mJ / cm ² or more, more preferably 3000 mJ / cm ² or less, / cm < ² > or less.

The temperature condition in the polymerization step is usually room temperature.

The polymerization may be carried out in any atmosphere such as an inert gas (nitrogen, argon, etc.) or air, but it is preferably carried out in an inert gas atmosphere from the viewpoint of improving the curability.

(Polymerizable liquid crystal compound)

The type of the polymerizable liquid crystal compound is not particularly limited as long as it exhibits a nematic phase and has an aspect ratio (length of long axis / short axis length) of the molecular structure of 3 or less.

The polymerizable liquid crystal compound is not limited to one kind, and two or more kinds may be used in combination. When two or more kinds of polymerizable liquid crystal compounds are contained, at least one of them may be a compound having an aspect ratio (length of long axis / short axis length) of the molecular structure of 3 or less.

Examples of the polymerizable liquid crystal compound include compounds represented by the following formulas (1-1) to (1-4).

In the above formulas (1-1) to (1-4)

X ¹ , X ³ and X ⁴ are each independently -O- or -S-;

X ² is -CH = or -N =;

W ¹ is an aromatic ring which may contain a hetero atom and the aromatic ring may be a single bond or -C≡C- connected to a 5-membered ring containing X ¹ and X ² , and the number of π electrons is 6 to 16 ;

W ² is a condensed ring of oxygen, sulfur, a 5-membered ring, a 6-membered ring or a 5-membered ring and a 6-membered ring;

W ³ each independently represents cyano, alkoxycarbonyl having 1 to 10 carbon atoms or alkanoyl having 1 to 10 carbon atoms, and at least one -CH ₂ - in the alkoxycarbonyl and alkanoyl is -O-, -COO -, -OCO-, -CH = CH- or -C = C-;

W ⁴ represents a divalent linking group selected from the group consisting of -CH = CH-, -C≡C-, an aromatic ring which may contain a hetero atom or a combination thereof;

R ¹ is independently a group represented by the following formula (2-1)

In the formula (2-1), A ¹ is each independently 1,4-phenylene or 1,4-cyclohexylene. In this 1,4-phenylene, at least one hydrogen is fluorine, cyano , Formyl, trifluoroacetyl, trifluoromethyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms; Z ¹ each independently represents a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -OCH ₂ CH ₂ O-, -CH ₂ CH ₂ COO-, -OCOCH ₂ CH ₂ -, -CH ₂ CH ₂ OCO- or -COOCH ₂ CH ₂ -; m is independently an integer of 1 or 2; Y ¹ is a single bond, -O-, -COO-, -OCO- or -OCOO-; Q ¹ is a single bond or alkylene having 1 to 20 carbon atoms, and at least one -CH ₂ - in the alkylene is -O-, -COO-, -OCO-, -CH = CH- or -C≡ C-; PG is a polymerizable group represented by any one of the following formulas (PG-1) to (PG-8).

In the formulas (PG-1) to (PG-8), R ³ is each independently hydrogen, halogen, methyl, ethyl or trifluoromethyl;

In the above formulas (1-1) to (1-4)

R ² is independently a group represented by the following formula (2-2)

In the formula (2-2), A ² is each independently 1,4-phenylene or 1,4-cyclohexylene, and in 1,4-phenylene, at least one hydrogen is fluorine, trifluoro Methyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms; Z ² is a single bond; n is independently an integer of 0 to 3; R ⁴ is selected from the group consisting of hydrogen, fluorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of 1 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms or alkoxycarbonyl of 1 to 20 carbon atoms to be.

As the compound represented by the above formulas (1-1) to (1-4), Z ¹ in the formula (2-1) is independently -COO-, -OCO-, -CH ₂ CH ₂ COO - or -OCOCH ₂ CH ₂ - and; PG is preferably a compound which is a polymerizable group represented by the above formula (PG-1).

Further, the polymerizable liquid crystal compound is more preferably a compound represented by the above formula (1-1) or (1-3).

Hereinafter, preferred examples of the compound represented by the formula (1-1) are shown.

Hereinafter, preferred examples of the compound represented by the formula (1-2) are shown.

Hereinafter, preferred examples of the compound represented by the formula (1-3) are shown.

Hereinafter, preferred examples of the compound represented by the formula (1-4) are shown.

In the formulas (1-1-1) to (1-4-4), R ⁴ represents hydrogen, fluorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of 1 to 20 carbon atoms, Alkoxy having 1 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms or alkoxycarbonyl having 1 to 20 carbon atoms, R ⁵ is hydrogen, fluorine, An alkyl group having 1 to 5 carbon atoms, an alkanoyl group having 1 to 5 carbon atoms, or a thioalkyl group having 1 to 5 carbon atoms, Y ¹ is a single bond, -O-, -COO-, -OCO- or -OCOO-, Q ¹ is a single bond or alkylene having 1 to 20 carbon atoms, and at least one -CH ₂ - in the alkylene is -O-, -COO-, -OCO-, -CH = CH- or -C? C-, and PG is a polymerizable group represented by any one of formulas (PG-1) to (PG-8).

In the formulas (PG-1) to (PG-8), each R ³ is independently hydrogen, halogen, methyl, ethyl or trifluoromethyl.

Examples of other polymerizable liquid crystal compounds include compounds represented by the following formula (M1) and compounds represented by the formula (M2).

In the formulas (M1) and (M2), each A ^M independently represents 1,4-phenylene, 1,4-cyclohexylene, 1,4- Diyl or fluorene-2,7-diyl, wherein at least one of the hydrogens is fluorine, chlorine, cyano, hydroxy, formyl, trifluoroacetyl, difluoromethyl, tri Fluoromethyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms; Z ^M each independently represents a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -COS-, -SCO-, -OCOO-, -CONH-, -NHCO-, -CF _{2 O-, -OCF 2 -, -CH} 2 CH 2 -, -CF 2 CF 2 -, -CH = CHCOO-, -OCOCH = CH-, -CH 2 CH 2 COO-, -OCOCH 2 CH 2 -, -CH = CH-, -N = CH-, -CH = N-, -N = CCH 3 -, -CCH 3 = N-, -N = N- or a C≡C-; X ^M is hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of 1 to 20 carbon atoms, alkenyl of 1 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms or alkoxy of 1 to 20 carbon atoms Carbonyl; q is an integer of 1 to 4;

a is an integer from 0 to 20; R ^M is hydrogen or methyl; Y ^M is a single bond, -O-, -COO-, -OCO- or -OCOO-.

Here, when q is 2 or more, these A ^M and Z ^M may be different each time they are repeated.

In the formula (M1) and the compound represented by the formula (M2), the compound represented by the formula (M1) is more preferable, and in the formula (M1), each ^M is independently 1,4- Cyclohexylene, but at least one of A ^M is 1,4-cyclohexylene, and in said 1,4-phenylene or 1,4-cyclohexylene, at least one hydrogen is fluorine, Substituted with 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms, which may be substituted with halogen, chlorine, trifluoroacetyl, difluoromethyl, trifluoromethyl, It may be; Z ^M each independently represents a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CH ₂ CH ₂ -, -CH ₂ CH ₂ COO- or -OCOCH ₂ CH ₂ - ; q is an integer of 1 or 2; X ^M is hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of 1 to 20 carbon atoms, alkenyl of 1 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms or alkoxy of 1 to 20 carbon atoms Carbonyl; a is an integer from 0 to 20; R ^M is hydrogen or methyl; Y ^M is preferably a single bond, -O-, -COO-, -OCO- or -OCOO-.

As the other polymerizable liquid crystal compound, a compound represented by the following formula (M3) can be exemplified.

In formula (M3), A ^M is each independently 1,4-phenylene or 1,4-cyclohexylene, wherein at least one hydrogen is fluorine, chlorine, cyano, hydroxy, formyl, Trifluoroacetyl, difluoromethyl, trifluoromethyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms ; Z ^M each independently represents a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -COS-, -SCO-, -OCOO-, -CONH-, -NHCO-, -CF _{2 O-, -OCF 2 -, -CH} 2 CH 2 -, -CF 2 CF 2 -, -CH = CHCOO-, -OCOCH = CH-, -CH 2 CH 2 COO-, -OCOCH 2 CH 2 -, -CH = CH-, -N = CH-, -CH = N-, -N = CCH 3 -, -CCH 3 = N-, -N = N- , or -C≡C-, and; c and d are each an integer of 0 to 3, and 1? c + d? 4; a is an integer from 0 to 20; R ^M is hydrogen or methyl; Y ^M is a single bond, -O-, -COO-, -OCO- or -OCOO-. Here, when c and d are two or more, these A ^M and Z ^M may be different each time they are repeated.

The compound represented by the formula (M1) is a monofunctional polymerizable liquid crystal compound, and it is easy to control the liquid crystal temperature range, optical characteristics and orientation of the liquid crystal composition. The compound represented by the formula (M2) is a bifunctional polymerizable liquid crystal compound. Since the polymer has a three-dimensional structure, it is a hard polymer as compared with the compound represented by the formula (M1) having one polymerizable group. The compound represented by the formula (M3) is a bifunctional polymerizable liquid crystal compound, which can form a more rigid network and becomes a harder polymer than a compound having one and two polymerizable groups. The compound having at least one of A ^M in the formulas (M1) to (M2) and having 1,4-cyclohexylene is easy to control the wavelength dispersion characteristics. Hereinafter, the compounds represented by the formulas (M1), (M2) and (M3) and the compounds derived therefrom may be collectively referred to as the formula (M).

Hereinafter, preferred examples of the compound represented by the formula (M1) are shown.

In the formulas (M1-1) to (M1-24), R ^M is each independently hydrogen or methyl, and a is independently an integer of 1 to 12.

Hereinafter, preferred examples of the compound represented by the formula (M2) are shown.

In the formulas (M2-1) to (M2-31), R ^M is each independently hydrogen or methyl, and a is independently an integer of 1 to 12. When two or more a's are present in the formula, any two a's may be the same or different.

Hereinafter, preferred examples of the compound represented by the formula (M3) are shown.

In the formulas (M3-1) to (M3-10), R ^M is each independently hydrogen or methyl, and a is independently an integer of 1 to 12. When two or more a's are present in the formula, any two a's may be the same or different.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is generally 5% by weight or more, preferably 10% by weight or more, more preferably 15% by weight or more, usually 95% by weight or less, Or less, more preferably 60 wt% or less.

When the polymerizable liquid crystal compound contains a compound represented by any one of formulas (1-1) to (1-4), it is preferable to use a compound represented by any one of formulas (1-1) to 1-4) preferably contains 10 to 100% by weight, more preferably 50 to 100% by weight. Within the above-mentioned range, it is easy to control the wavelength dispersion of the refractive index anisotropy, and satisfactory coating properties can be ensured.

(Polymerization initiator)

The polymerizable liquid crystal composition includes a photopolymerization initiator. More specifically, it includes a photo radical polymerization initiator.

Examples of the photo radical polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (DAROCURE 1173), 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy- (Irgacure 651), 1-hydroxycyclohexyl-phenyl-ketone (Irgacure 184), Irgacure 127, Irgacure 500 (a mixture of Irgacure 184 and benzophenone ), Irgacure 2959, Irgacure 907, Irgacure 369, Irgacure 379, Irgacure 754, Irgacure 1300, Irgacure 819, Irgacure 1700, Irgacure 1800, Irgacure 1850, Irgacure 1870, Darocure 4265, Darocure MBF, Darocure TPO, Irgacure 784, Irgacure 754, and the like. The above-mentioned DARACURE and IRGACURE are all trade names of products sold by BASF Japan Co., Ltd.

As the photoradical polymerization initiator, a photopolymerization initiator having an oxime ester may be used. The photopolymerization initiator having an oxime ester will be exemplified below. The photopolymerization initiator may be a commercially available product. Specifically, the compounds described in Japanese Patent Application Laid-Open No. 2011-132215, compounds No. 1 to No. 108 described in paragraphs 0032 to 0046, Japanese Patent Laid-open No. 2004-534797, compounds disclosed in WO2009 / 147031 A compound having an oxime ester moiety as disclosed in Japanese Patent Application Laid-Open No. 2006-251374, a compound having an oxime ester moiety as described in JP-A-2009-286976 , A compound having an oxime ester moiety described in JP-A-2009-29929, and the like.

Among the photo radical polymerization initiators, NCI-930, N-1919 (manufactured by ADEKA), Irgacure 907, Irgacure OXE01, Irgacure OXE02, Irgacure 369, Irgacure 379 , BASF Japan Co., Ltd.), and the like.

As the photo radical polymerization initiator, the following photo radical polymerization initiator system can be used.

(trichloromethyl) triazine, 2- (p-butoxystyryl) -5-trichloromethyl-1,3,4-oxadiazole, 9-phenyla (4-isopropylphenyl) -2-hydroxy-2-methyl < / RTI > 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2,4-diethylamino acid / p-dimethylaminobenzoic acid Methyl mixture, benzophenone / methyl triethanol amine mixture.

The content of the photopolymerization initiator in the polymerizable liquid crystal composition is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, and usually 20% by weight or more based on the weight of the entire polymerizable liquid crystal compound By weight, preferably not more than 10% by weight, more preferably not more than 8% by weight.

These photopolymerization initiators may also be used in combination with a sensitizer. Examples of the sensitizer include isopropyl thioxanthone, diethyl thioxanthone, ethyl-4 dimethylaminobenzoate (Darocure EDB), 2-ethylhexyl-4-dimethylaminobenzoate (Darocure EHA) .

The photopolymerization initiator and sensitizer may be used alone or in admixture of two or more.

(Surfactants)

The polymerizable liquid crystal composition includes a surfactant. By including a surfactant, it is possible to adjust the shape and uniformity of the orientation, the coating property, and the recoatability.

Examples of the surfactant include ionic surfactants and nonionic surfactants. The surfactant is not limited to one kind, and two or more kinds of surfactants may be used in combination. Further, in consideration of the compatibility with the polymerizable liquid crystal compound and the solubility in solvents, it is more preferable to use a nonionic surfactant.

Examples of the ionic surfactant include titanate compounds, imidazolines, quaternary ammonium salts, alkylamine oxides, polyamine derivatives, polyoxyethylene-polyoxypropylene condensates, polyethylene glycol and its esters, sodium lauryl sulfate, ammonium lauryl sulfate , An alkyl substituted aromatic sulfonic acid salt, an alkyl phosphate, an aliphatic or aromatic sulfonic acid formalin condensate, lauryl amide propyl betaine, lauryl amino acetic acid betaine, a polyethylene glycol fatty acid ester, a polyoxyethylene alkylamine, a purple Perfluoroalkylsulfonic acid salts, perfluoroalkylcarboxylic acid salts, and the like.

Examples of the nonionic surfactant include vinyl-based, silicone-based, fluorine-based, and hydrocarbon-based surfactants.

Examples of the vinyl-based resin include polyalkyl acrylate, polyalkyl methacrylate, polyalkyl vinyl ether, polybutadiene, polyolefin, polyvinyl ether, and the like. For example, Polyflow No. 7, Polyflow No. 50EHF, Polyflow No. 54N, Polyflow No. 75, Polyflow No. 77, Polyflow No. 85HF, Polyflow No. 90, 380, BYK-381, BYK-392, BYK-399, BYK-359, BYK-351N, BYK- Silclean3700, TEGOFlow300, TEGOFlow370, and TEGOFlowZFS460.

Examples of the silicone system include polydimethylsiloxane, polyphenylsiloxane, special modified siloxane, fluorine modified siloxane, and surface-treated siloxane. For example, polyphore KL-400HF, polyflow KL-401, polyflow KL-402, polyflow KL-403, polyflow KL-404, BYK-300, BYK-302, BYK- BYK-310, BYK-310, BYK-315, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK- 344, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-370, BYK-371, BYK- BYK-3510, BYK-3530, BYK-3570, BYK-Silclean 3720, and TEGOFlow425.

Examples of the fluorine-based polymer include fluorine-based polymers. For example, there may be mentioned BYK-340, POTGENT 251, POTGENT 212M, POTGENT 215M, POTGENT 250, POTGENT 222F, POTGENT 245F, POTGENT 208G, POTGENT 240G, POTGENT 220P, POTGENT 228P, FT-428, Megapack F-410, Megapack F-430, Megapack F-444, Megapack F-441, Megapack F- Mega Pack F-557, Mega Pack F-559, Mega Pack F-559, Mega Pack F-557, Mega Pack F-557, Mega Pack F- Megapack F-562, Megapack F-563, Megapack F-565, Megapack F-570, Megapack R-40, Megapack R-41, Megapack R-43 or Megapack R-94.

Examples of the hydrocarbon system include polyethylene, polypropylene, polyisobutylene, paraffin, liquid paraffin, chlorinated polypropylene, chlorinated paraffin, and chlorinated liquid paraffin.

The content of the surfactant in the solution containing the polymerizable liquid crystal compound is usually 0.001 or more, preferably 0.003 or more, more preferably 0.005 or more, and usually 5.0 or less, Preferably 4.0 or less, more preferably 3.0 or less. Within the above-mentioned range, it is easy to control the wavelength dispersion of the refractive index anisotropy, and satisfactory coating properties can be ensured.

(solvent)

The solvent is not particularly limited as long as it is capable of dissolving the polymerizable liquid crystal compound, and specific examples thereof include ester solvents, amide solvents, alcohol solvents, ether solvents, glycol monoalkyl ether solvents, aromatic hydrocarbons Based solvent, halogenated aromatic hydrocarbon solvent, aliphatic hydrocarbon solvent, halogenated aliphatic hydrocarbon solvent, alicyclic hydrocarbon solvent, ketone solvent, and acetate solvent. The solvent is not limited to one kind, and two or more kinds of solvents may be used in combination.

From the viewpoint of the solubility of the polymerizable liquid crystal compound, the solvent is preferably an amide-based solvent, an aromatic hydrocarbon-based or a ketone-based solvent, and in consideration of the boiling point of the solvent, ester solvents, alcohol solvents, ether solvents, It is also preferable to use a glycol monoalkyl ether solvent in combination. When a photo alignment film is used as the alignment film, it is necessary to lower the heating temperature of the solvent so as not to be eroded by the photo alignment film or to reduce the solvent damage. Examples of the solvent preferably used in such a case include an aromatic hydrocarbon solvent, a ketone solvent, an ester solvent, an ether solvent, an alcohol solvent, an acetate solvent and a glycol monoalkyl ether solvent.

Examples of the ester solvent include alkyl acetates such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, 3-methoxybutyl acetate, isobutyl acetate, pentyl acetate and isopentyl acetate, Ethyl propionate, methyl propionate, methyl propionate, methyl 3-methoxypropionate, ethyl propionate, propyl propionate and butyl propionate, alkyl butyrates such as methyl butyrate, ethyl butyrate, butyl butyrate, isobutyl butyrate and propyl butyrate Alkyl alcohols such as methyl lactate, ethyl lactate, isopropyl lactate, n-propyl lactate, isopropyl lactate, ethyl lactate, ethyl lactate, Butyl lactate and ethylhexyl lactate), alkyl pyruvate (e.g., ethyl pyruvate), monoacetin, gamma -Butyrolactone and -valerolactone, and the like.

Examples of the amide solvent include N, N-dimethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N, N- Diethylacetamide, N, N-dimethylacetamide dimethylacetal, N-methylcaprolactam, and dimethylimidazolidinone.

Examples of the alcohol solvents include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, tert -butyl alcohol, sec-butyl alcohol, N-hexanol, n-heptanol, n-octanol, 1-dodecanol, ethylhexanol, 3,5,5-trimethylhexanol, n-amyl alcohol , Hexafluoro-2-propanol, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, hexylene glycol, Butanediol, 2,3-butanediol, 1,5-pentanediol, 2,4-pentanediol, 2,5-hexanediol, 3-methyl-3-methoxybutanol, cyclohexanol and methylcyclohexanol. For example.

Examples of the ether solvents include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, bis (2-propyl) ether, 1,3-dioxolane, 1,4-dioxane and tetrahydrofuran ), And the like.

Examples of the glycol monoalkyl ether solvents include ethylene glycol monoalkyl ethers (e.g., ethylene glycol monomethyl ether and ethylene glycol monobutyl ether), diethylene glycol monoalkyl ethers (e.g., diethylene glycol monoethyl ether), triethylene glycol mono Alkyl ethers such as propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monobutyl ether; dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether; ethylene glycol monoalkyl ether acetates, Diethylene glycol monoalkyl ether acetate such as diethylene glycol monoethyl ether acetate, triethylene glycol monoalkyl ether acetate, propylene glycol monoalkyl ether acetate such as propylene glycol monomethyl ether acetate , Propylene glycol Diethyleneglycol monomethyl ether acetate), dipropylene glycol monoalkyl ether acetate (e.g., dipropylene glycol monomethyl ether acetate), diethylene glycol methyl ethyl ether, and the like.

Examples of the aromatic hydrocarbon solvents include aliphatic hydrocarbon solvents such as benzene, toluene, anisole, xylene, mesitylene, ethylbenzene, diethylbenzene, i-propylbenzene, n-propylbenzene, Terpene derivatives (such as p-cymene, 1,4-cineole, 1,8-cineol, D-limonene, D-limonene oxide, p- menthane,? -Pinene,? -Terpinene, ) And tetralin.

As the halogenated aromatic hydrocarbon solvent, chlorobenzene can be exemplified.

Examples of the aliphatic hydrocarbon-based solvent include hexane and heptane.

Examples of halogenated aliphatic hydrocarbon solvents include chloroform, dichloromethane, carbon tetrachloride, dichloroethane, trichlorethylene and tetrachlorethylene.

Examples of alicyclic hydrocarbon solvents include cyclohexane and decalin.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, cyclohexanone, cyclopentanone, and methylpropyl ketone.

Examples of the acetate solvent include ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl acetoacetate, and 1-methoxy-2-propyl acetate.

The content of the solvent in the polymerizable liquid crystal composition is usually 5% by weight or more, preferably 30% by weight or more, more preferably 40% by weight or more, usually 95% by weight or less, preferably 90% Preferably not more than 85% by weight. The lower limit of the above-mentioned range is a numerical value considering the solubility of the polymerizable liquid crystal compound and the optimum viscosity at the time of applying the solution. The upper limit is a numerical value in consideration of the cost of the solvent and the economic viewpoint such as the time and the amount of heat when the solvent is evaporated.

The polymerizable liquid crystal composition may contain a compound other than a polymerizable liquid crystal compound, a photopolymerization initiator, a surfactant and a solvent. Specifically, examples thereof include non-liquid crystalline polymerizable compounds, silane coupling agents, chain transfer agents, antioxidants, ultraviolet absorbers, light stabilizers (radical scavenger), and optically active compounds. Hereinafter, each of the additives will be described in detail with specific examples.

(Non-liquid crystalline polymerizable compound)

The polymerizable liquid crystal composition may contain a non-liquid crystalline polymerizable compound (a polymerizable compound other than the polymerizable liquid crystal compound).

Examples of the non-liquid crystalline polymerizable compound include compounds having no liquid crystallinity, such as vinyl derivatives, styrene derivatives, (meth) acrylic acid derivatives, oxirane derivatives, oxetane derivatives, sorbic acid derivatives, fumaric acid derivatives and itaconic acid derivatives . Other polymerizable compounds having no liquid crystalline property include a compound having one polymerizable group, a compound having two polymerizable groups, and a polyfunctional compound having three or more polymerizable groups. Further, the polymerizable compound other than the polymerizable liquid crystal compound is not limited to one kind, and two or more kinds of polymerizable compounds may be used in combination.

Examples of the compound having one polymerizable group include styrene, nucleus substituted styrene, acrylonitrile, vinyl chloride, vinylidene chloride, vinylpyridine, N-vinylpyrrolidone, vinylsulfonic acid, ), alpha, beta -ethylenically unsaturated carboxylic acids (e.g., acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid), alkyl esters of (meth) acrylic acid (C1 to C18 of hydroxyalkyl), aminoalkyl ester of (meth) acrylic acid (having 1 to 18 carbon atoms of aminoalkyl), ether oxygen-containing alkyl ester of (meth) acrylic acid Such as methoxyethyl ester, ethoxyethyl ester, methoxypropyl ester, methylcarbyl ester, ethylcarbyl ester, and butylcarbyl ester), N-vinylacetamide, p-tert- butyl Benzoic acid Vinyl, vinyl N, N-dimethylaminobenzoate, vinyl benzoate, vinyl pivalate, vinyl 2,2-dimethylbutyric acid, vinyl 2,2-dimethylpentanoate, vinyl 2-methyl-2-butylacetate, vinyl stearate (Meth) acrylate, isobornyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, (Meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, 2-acryloyloxyethylsuccinic acid, 2- acryloyloxyethyl hexahydrophthalic acid, Acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, Polyethylene glycol, polypropylene glycol (Meta) acrylic acid esters or di (meth) acrylic acid esters of polyalkylene glycols such as a copolymer of ethylene oxide and propylene oxide, or an alkyl group having 1 to 6 carbon atoms, (Meth) acrylic acid esters of polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and copolymers of ethylene oxide and propylene oxide.

Examples of the compound having two polymerizable groups include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol acrylate, neopentyl glycol diacrylate, dimethyl Triethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, bisphenol A EO-added diacrylate, bisphenol A glycidyldiacrylate (VISCOT V # 700), polyethylene glycol diacrylate, and methacrylate compounds of these compounds.

Examples of the compound having three or more polymerizable groups include pentaerythritol tri (meth) acrylate, trimethylol propane tri (meth) acrylate, trimethylol EO added tri (meth) acrylate, tris (meth) (Meth) acryloyloxyethyl isocyanurate, alkyl-modified dipentaerythritol tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethyl (Meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meta) acrylate, dipentaerythritol tetra ) Acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, bis Bit V # 802 and the like (functional group number = 8), bis coat V # 1000 (average functional group number = 14). "Viscot" is a trade name for a product manufactured by Osaka Organic Chemical Co., Ltd. A functional group having a functionality of 16 or more is obtained by acrylating them using Boltorn H20 (16-functional), Boltorn H30 (32-functional) and Boltorn H40 (64-functional), which are marketed by Perstorp Specialty Chemicals.

Examples of the polymerizable compound other than the other polymerizable liquid crystal compounds include polymerizable fluorene derivatives having a cardo structure. These compounds are suitable for controlling the orientation direction and further increasing the degree of curing of the polymer. Examples of the polymerizable fluorene derivative having a cardo structure are represented by formulas (α-1) to (α-3).

In the formulas (α-1) to (α-3), Rα is independently hydrogen or methyl, and s is independently an integer of 0 to 4. When there are two or more s in the formula, any two s may be the same or different.

As the polymerizable compound other than the other polymerizable liquid crystal compounds, a polymerizable compound having a bisphenol structure is also exemplified. These compounds are suitable for assisting in film-forming ability and orientation uniformity. Examples of polymerizable bisphenol derivatives are represented by formulas (N-1) to (N-6).

The content of the non-liquid crystalline polymerizable compound in the polymerizable liquid crystal composition may be added as long as the liquid crystal phase is not damaged. The weight ratio of the polymerizable liquid crystal compound to the total weight of the polymerizable liquid crystal compound is preferably from 0.01 to 0.50, and more preferably from 0.03 to 0.30.

(Silane coupling agent)

The polymerizable liquid crystal composition may contain, for example, a silane coupling agent for controlling adhesion to a substrate or for other purposes.

Examples of the silane coupling agent include vinyltrialkoxysilane, 3-isocyanatepropyltriethoxysilane, N- (2-aminoethyl) 3-aminopropyltrialkoxysilane, N- (1,3-dimethylbutylidene) -3- (Trialkoxysilyl) -1-propanamine, 3-glycidoxypropyltrialkoxysilane, 3-chlorotrialkoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrialkoxysilane and the like . In these compounds, a dialkoxymethylsilane in which one of alkoxy (3) is substituted with methyl can also be used as a silane coupling agent.

The content of the silane coupling agent in the polymerizable liquid crystal composition is usually 0.01 or more, preferably 0.03 or more, and usually 0.2 or less, preferably 0.1 or less, in terms of the weight ratio with respect to the weight of the entire polymerizable liquid crystal compound. These silane coupling agents may be used alone or in admixture of two or more.

(Chain transfer agent)

The polymerizable liquid crystal composition may also contain a chain transfer agent, for example, to control the polymerization reaction rate, adhesion, or mechanical properties of the polymer or for other purposes. By including a chain transfer agent, the length of the polymer chain or the length of the two crosslinked polymer chains in the polymer film can be controlled. These lengths can be controlled simultaneously. When the amount of the chain transfer agent is increased, the polymerization reaction rate is lowered and the length of the polymer chain is decreased. Preferred chain transfer agents include thiol compounds and styrene dimers. These chain transfer agents may be used alone or in combination of two or more.

Examples of the thiol chain transfer agent include monofunctional thiol compounds such as dodecanethiol, 2-ethylhexyl- (3-mercaptopropionate and the like, trimethylolpropane tris (3-mercaptopropionate), penta (3-mercaptobutyryloxy) butane (carlens MT BD1), pentaerythritol tetrakis (3-mercaptobutyrate) ( (3H, 3H, 5H) -triene (car lens MT PE1) and 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine- Lens MT NR1), etc. The " car lens " is a trade name of Showa Denko KK. As the thiol compounds other than those described above, those described in paragraphs 0042 to 0043 of International Publication No. 2013/080855 Thiol compounds, and compounds described in p.23 to p.24, line 27 to p.23 of International Publication No. 2008/077261. Examples of styrene dimers include, methylene styrene dimer (2,4-diphenyl-4-methyl-1-pentene), 1,1-diphenylethylene and quinoexester QE-2014 can also be used. It is a trade name of a product manufactured by Kawasaki Chemical Industry Co., Ltd.

Examples of the styrene dimer-based chain transfer agent include 2,4-diphenyl-4-methyl-1-pentene and 2,4-diphenyl-1-butene.

(Antioxidant)

The polymerizable liquid crystal composition may contain an antioxidant for improving storage stability and weather resistance or for other purposes. As the antioxidant, phenol-based antioxidants, sulfur-based antioxidants, and phosphoric acid-based antioxidants can be used. These antioxidants may be used alone or in admixture of two or more.

As the antioxidant, Adekastab AO-20, AO-30, AO-40, AO-50, AO-60, AO-80 manufactured by ADEKA, Sumilizer BHT sold by Sumitomo Chemical Co., Irganox1035, Irganox1035, Irganox1076, Irganox1098, Irganox1135, Irganox1330, Irganox1425, Irganox1520, Irganox1726, Irganox245, Irganox259, Irganox3114, Irganox3790, Irganox5057 and Irganox1057 sold by BASF Japan Co., Irganox 565 and the like.

(Ultraviolet absorber)

The polymerizable liquid crystal composition may contain, for example, an ultraviolet absorber for improving weather resistance or for other purposes. Examples of ultraviolet absorbers include Tinuvin PS, Tinuvin P, Tinuvin 99-2, Tinuvin 109, Tinuvin 213, Tinuvin 234, Tinuvin 326, Tinuvin 328, Tinuvin 329, Tinuvin 384-2, Tinuvin B-CAP, Hostavin VSU, Tinuvin A, Tinuvin B-CAP, Tinuvin A, Tinuvin A, Adecastab LA-32, adecastab LA-32, adecastab LA-34, adecastab LA-36, adecastab LA-31, adecastab 1413 and adecastab LA-51. &Quot; Tinuvin " is a trade name of BASF Japan, " Hosutabin " is a trade name of Clariant Japan Co., and " Adekastab " These ultraviolet absorbers may be used alone or in admixture of two or more.

(Light stabilizer)

The solution containing the polymerizable liquid crystal compound may contain, for example, a light stabilizer (radical scavenger) for improving weatherability or for other purposes.

Examples of the light stabilizer include Tinuvin 111FDL, Tinuvin 123, Tinuvin 144, Tinuvin 152, Tinuvin 292, Tinuvin 622, Tinuvin 770, Tinuvin 765, Tinuvin 780, Tinuvin 905, Tinuvin 5100, 50, 5060, Tinuvin 5151, KIMASOV 119FL, KIMASOV 944FL, KIMASOV 944LD, Adecastab LA-52, Adecastab LA-57, Adecastab LA-62, Adecastab LA-67 , Adascastab LA-63P, Adecastab LA-68LD, Adecastab LA-77, Adecastab LA-82, Adecastab LA-87, Good Light UV-3034 from Goodrich Co., for example. &Quot; KIMASOV " is a trade name of BASF Japan Co., Ltd. These light stabilizers may be used alone or in combination of two or more thereof.

(Optically active compound)

The polymerizable liquid crystal composition may contain a chiral compound, that is, an optically active compound. Examples of optically active compounds include compounds represented by formulas (Op-1) to (Op-25).

In the formulas (Op-1) to (Op-25), Ak represents alkyl of 1 to 15 carbon atoms or alkoxy of 1 to 15 carbon atoms, Me, Et and Ph represent methyl, . P ² is a polymerizable group, and is preferably a group containing (meth) acryloyloxy, vinyloxy, oxiranyl, or oxetanyl.

As an optically active compound, there is one described in paragraph 0170 of paragraphs 0159 to 81 in p. 70 of Japanese Patent Laid-Open Publication No. 2011-148762.

A solution containing an optically active compound or a solution containing a polymerizable compound having an optically active functional group is coated on an oriented support substrate and polymerized to obtain a retardation film exhibiting a helical structure (twisted structure) . By polymerization of the polymerizable liquid crystal compound, this helical structure is fixed. The properties of the obtained liquid crystal film depend on the screw pitch of the obtained helical structure. The screw pitch length can be adjusted by the kind of the optically active compound and the addition amount. There may be only one optically active compound to be added, but a plurality of optically active compounds may be used for the purpose of canceling the temperature dependency of the screw pitch.

As a polymerizable liquid crystal composition, a polymerizable liquid crystal composition is applied on a support substrate to produce an optically anisotropic film of good quality by the production method of the present invention, and the phase transition temperature from the liquid crystal phase to the isotropic phase the case where the temperature T _NI, preferably from 120 ℃ ≥T _NI ≥45 ℃. When T _NI is higher than 120 ° C, crystallization (crystallization) and uniformity of orientation tend to occur at room temperature. When T _NI is less than 45 ° C, it is difficult to obtain a uniform orientation.

(Supporting substrate)

The supporting substrate to which the polymerizable liquid crystal composition is applied is not particularly limited and a well-known one can be appropriately selected. Examples of the material include plastics, metals such as aluminum, iron and copper, alkali glass, borosilicate glass, glass such as lead glass For example.

Examples of the plastic include polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyetherketone, polyketone sulfide, polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate Polybutylene terephthalate, polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, polypropylene, cellulose, triacetylcellulose and its partial saponification, epoxy resin, phenolic resin, and Cycloolefin-based resins, and the like.

Examples of the cycloolefin-based resin include norbornene-based resins and dicyclopentadiene-based resins, but are not limited thereto. Of these, those having no unsaturated bond or having an unsaturated bond hydrogenated are preferably used. For example, hydrogenated products of ring-opening (co) polymers of one or more norbornene monomers, addition (co) polymers of one or more norbornene monomers, copolymers of norbornene monomers and olefin monomers ( Ethylene,? -Olefin, etc.), addition copolymers of a norbornene monomer and a cycloolefin monomer (cyclopentene, cyclooctene, 5,6-dihydrodicyclopentadiene, etc.), and modified products thereof Specific examples thereof include ZEONEX, ZEONOR (all trade names, manufactured by Nippon Zeon), ARTON (trade name, manufactured by JSR Corporation), TOPAS (trade name, manufactured by Tico Corporation), APEL Ltd.), Esushina (trade name, manufactured by Sekisui Chemical Co., Ltd.) and OPTOREZ (trade name, manufactured by Hitachi Chemical Co., Ltd.).

The form of the supporting substrate is usually a sheet or film type.

In the case of a film-like supporting substrate, it may be a monoaxially stretched film or a biaxially stretched film.

Further, the film may be subjected to surface treatment such as hydrophilization treatment such as corona treatment or plasma treatment, or hydrophobic treatment. The hydrophilization treatment method is not particularly limited, but a corona treatment or a plasma treatment is preferable, and a particularly preferable method is a plasma treatment. As the plasma treatment, the methods described in JP-A-2002-226616 and JP-A-2002-121648 can be used. An anchor coating layer may also be formed to improve the adhesion between the liquid crystal film and the plastic film. Such an anchor coating layer has no problem as long as it improves the adhesion between the liquid crystal film and the plastic film, either an inorganic material or an organic material. The plastic film may be a laminated film.

In the case where the optically anisotropic film of homogeneous orientation and hybrid orientation is formed on the supporting substrate, physical and mechanical surface treatment by rubbing or the like may be performed prior to application of the polymerizable liquid crystal composition. In the case of forming an optically anisotropic film of homeotropic orientation, surface treatment such as rubbing is often not performed, but rubbing treatment may be performed in order to prevent alignment defects and the like. An arbitrary method can be employed for the rubbing treatment, but a method in which a rubbing cloth made of a material such as rayon, cotton, polyamide or the like is wound around a metal roll or the like and moved while rotating the roll in contact with the supporting substrate or the polymer film , And a method of moving the supporting substrate side while fixing the roll is adopted. The rubbing treatment may be carried out directly on the supporting substrate, or a polymer coating film such as polyimide, which is generally referred to as an alignment film, may be formed on the supporting substrate in advance, and the polymer coating film may be rubbed. The rubbing treatment method is as described above. Depending on the kind of the supporting substrate, it is also possible to impart the alignment ability by obliquely depositing silicon oxide on the surface.

In addition, in the case of forming optically anisotropic films of homogeneous orientation and hybrid orientation, in addition to performing physical and mechanical surface treatment by rubbing or the like, it is also possible to use polyimide, polyacrylate or the like And a polarizing UV treatment may be applied to the polymer coating.

≪ Optical anisotropic film &

The production method of the present invention is a production method capable of producing an optically anisotropic film having uniform orientation of constituent molecules, but the kind of orientation of the optically anisotropic film to be produced is not particularly limited and can be appropriately selected according to the purpose.

The orientation of the constituent molecules of the optically anisotropic film is classified into homogeneous (parallel), homeotropic (vertical), tilt (inclined), and twisted (twisted) based on the magnitude of the tilt angle and the like. The tilt angle is an angle between the orientation of the constituent molecules and the supporting substrate. Homogeneous refers to a state in which the alignment state is parallel to the substrate and aligned in one direction. An example of the tilt angle of the homogeneous orientation is 0 ° to 5 °. The homeotropic refers to a state in which the alignment state is perpendicular to the substrate. Examples of tilt angles in homeotropic alignment are 85 ° to 90 °. The tilt refers to a state in which the alignment state is standing vertically from parallel with the distance from the substrate. An example of the tilt angle (tilt angle) in the tilt alignment is 5 ° to 85 °. The twist refers to a state in which the alignment state is parallel to the substrate, but is twisted in a stepwise manner about the screw axis. Examples of tilt angles in the twist orientation are 0 ° to 5 °.

The orientation of the constituent molecules can be achieved by, for example, applying an optically anisotropic film of homogeneous orientation or hybrid orientation to the optically anisotropic film of a homogeneous orientation or a hybrid orientation in the case of coating on a support substrate coated with a plastic thin film or a thin plastic film subjected to orientation treatment such as rubbing treatment Can be manufactured. In addition, when the above-mentioned optically active compound is added to a solution, an optically anisotropic film of twist orientation can be produced. Further, when a compound having a cardo structure or a monofunctional liquid crystal compound is added to a solution, an optically anisotropic film of homeotropic orientation can be produced. Further, the tilt angle can be controlled by adjusting, for example, the types of the polymerizable liquid crystal compound, the solvent, the compound added to the solution, the composition ratio, and the like. Further, the tilt angle can be controlled also by the kind of the supporting substrate or coating, the rubbing condition, the drying condition or the heat treatment condition of the coating film, the irradiation atmosphere in the polymerization process, the temperature during irradiation,

The shape, physical properties and the like of the optically anisotropic film produced by the production method of the present invention are not particularly limited and can be appropriately selected according to the purpose.

The thickness of the optically anisotropic film is usually 0.1 占 퐉 or more, preferably 0.5 占 퐉 or more, more preferably 1 占 퐉 or more, and usually 500 占 퐉 or less, preferably 300 占 퐉 or less, more preferably 200 占 퐉 or less.

The birefringence? N (550) of the optically anisotropic film is usually 0.03 or more, preferably 0.04 or more, more preferably 0.05 or more, and usually 0.5 or less, preferably 0.4 or less, more preferably 0.3 or less.

The thickness of the optically anisotropic film can be made thinner as the birefringence (value indicating optical anisotropy) is higher. The thinner the thickness, the better the optical characteristics such as the haze value and the transmittance.

It is preferable that the optically anisotropic film has a birefringence Δn (λ) with respect to light of a wavelength λ nm of Δn (450) / Δn (550) ≤1.05 and Δn (450) / Δn (550) , More preferably? N (450) /? N (550)? 0.95. If it is within the above-mentioned range, it can be utilized for various applications as an optically anisotropic film having excellent wavelength dispersion control characteristics.

The optically anisotropic film produced by the production method of the present invention may have a selective reflection characteristic for selectively reflecting visible light. The selective reflection characteristic is that the helical structure acts on incident light and reflects circularly polarized light or elliptically polarized light. Since the selective reflection characteristic is represented by λ = n · Pitch (λ is the central wavelength of the selective reflection, n is the average refractive index, and Pitch is the screw pitch), the center wavelength λ and the wavelength width Δλ are changed by changing n or Pitch Can be adjusted appropriately. In order to improve the color purity, the wavelength width DELTA lambda can be made small, and when the wide band reflection is desired, the wavelength width DELTA lambda can be made large.

A negative C plate (Negative C plate) described in W. H. de Jeu, Physical Properties of Liquid Crystalline Materials, Gordon and Breach, New York (1980) can be prepared by making the screw pitch shorter than the wavelength of the visible light. In order to shorten the screw pitch, this can be achieved by using an optically active compound having a large twisting force (HTP: helical twisting power) and increasing the addition amount thereof. Concretely, by setting λ to 350 nm or less, preferably 200 nm or less, a negative C plate can be prepared. This negative type C plate is an optical compensation film suitable for display elements such as VAN type, VAC type, and OCB type of liquid crystal display elements. Further, the optically anisotropic film can be used as a reflective film whose reflection wavelength range described in Japanese Patent Application Laid-Open No. 2004-333671 is set to near infrared (wavelength: 800 to 2500 nm) by making the screw pitch longer than visible light. The screw pitch can be increased by using, for example, an optically active compound having a small twisting force, or by reducing the amount of the optically active compound to be added.

The optically active compound may be any optically active compound as long as it can induce the helical structure and suitably mix with the base liquid crystal composition. In addition, any of the polymerizable compound and the non-polymerizable compound may be used, and a compound that is optimal for the purpose may be added. When considering heat resistance and solvent resistance, a polymerizable compound is preferable. Also, among the optically active compounds, a large twisting force (HTP: helical twisting power) is preferable in order to shorten the screw pitch. Representative examples of compounds having a large twisting force are disclosed in British Patent Application Publication No. 2298202 and German Patent Application Publication No. 10221751.

<Optical element, liquid crystal display device, organic EL display device>

The use of the optically anisotropic film produced by the production method of the present invention is not particularly limited, but may be an optically anisotropic film directly formed or integrated with a polarizing plate or the like and made into a liquid crystal display device (in particular, an active matrix type liquid crystal display device or a passive matrix type liquid crystal display device ) Or an organic EL display device

As a use example of the liquid crystal display device, it is possible to arrange the liquid crystal cell inside the liquid crystal cell because the amount of impurities leaking into the liquid crystal filled in the liquid crystal cell of the liquid crystal display device is very small. For example, by applying the method disclosed in Japanese Patent Application Laid-Open No. 2008-01943, it is possible to further improve the function of the color filter by forming the polymerizable liquid crystal layer of the present invention on the color filter.

When used as an optical element integrated with a polarizing plate or the like, it is disposed outside the liquid crystal cell. Examples of the polarizing plate include, but are not limited to, an absorption type polarizing plate doped with iodine, a reflection type polarizing plate such as a wire grid polarizing plate which are widely used, and the like. When the polarizing plate includes the stretched film as a component, it is disposed outside the liquid crystal cell. In the case where the polarizing plate has an inorganic film as a constituent element, the polarizing plate may be disposed on the outside of the liquid crystal cell or on the inside of the liquid crystal cell.

As the types of liquid crystal display devices, IPS type (in-plane switching), OCB type (optically compensated birefringence), TN type (twisted nematic), STN type (super twisted nematic), ECB type VCP / VAC type (vertically aligned nematic / cholesteric), OMI type (optical mode interference), DAP type (deformation effect of alignment phase), CSH type (color super-homeotropic) ), SBE type (super birefringence effect), and the like. Further, an optically anisotropic film may be used as a phase retarder for a display element such as a guest-host type, ferroelectric molding, antiferroelectric molding and the like.

The manufacturing method of the liquid crystal display device is not particularly limited and can be appropriately selected from known methods. For example, a transparent electrode such as ITO is formed on the optically anisotropic film produced by the production method of the present invention by a vacuum film formation method such as sputtering, and an alignment film of the vertical alignment mode is formed after the electrode is formed, A liquid crystal having a negative dielectric anisotropy is injected to form a liquid crystal display device in a vertical alignment mode. Since the optically anisotropic film is made rigid by the additional heat curing treatment, it can be disposed in the liquid crystal cell, and an adhesive for bonding the stretching type optical compensation film and liquid crystal cell, which have been used so far, becomes unnecessary. As a result, it is possible to prevent the lowering of the contrast due to the interface reflection of the adhesive, which is useful for high contrast (high quality) of the liquid crystal display of the vertical alignment mode.

The optimum values of the parameters such as the pitch and thickness of the helical spiral in the twist orientation required for the optically anisotropic medium having the twist orientation depend strongly on the type of the liquid crystal display device to be compensated and the optical parameters thereof,

An example of application to an organic EL display device is used as a circularly polarizing plate integrated with a polarizing plate or the like for the purpose of preventing reflection. Since the organic EL display device has a highly reflective metal layer, problems such as reflection of external light and background overlapping are likely to occur. Therefore, it is an object of the present invention to prevent these problems by providing the circular polarizer on the viewing side. In order to exhibit the function as a circularly polarizing plate, it is preferable to design the optically anisotropic film as a 1/4 wavelength plate.

The optically anisotropic film may contain an additive such as a dichroic dye. As the dichroic dye, a dye comprising anthraquinone, naphthoquinone or azobenzene is preferable. The liquid crystal film of the homogeneous orientation in which the dichroic dye and the dichroic dye are combined can also be used as an absorption type polarizing plate. Further, a homogeneous liquid crystal film composed of a fluorescent dye combined with a fluorescent dye can also be used as a polarized light emitting type film.

[Example]

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

<Phase transition temperature>

A sample was placed on a hot plate of a melting point measuring apparatus equipped with a polarization microscope, and the temperature was elevated at a rate of 3 ° C / minute, and the temperature at which the phase was transferred to another phase was measured. C means crystal, N means nematic phase, S means smectic phase, and I means isotropic liquid. The NI point is the upper limit temperature of the nematic phase or the transition temperature from the nematic phase to the isotropic liquid. &Quot; C50N63I &quot; indicates transition from a crystal to a nematic phase at 50 DEG C and a transition from a nematic phase to an isotropic liquid at 63 DEG C. The parentheses indicate the monotrophic liquid crystal phase.

The sample can be obtained by applying the polymerizable liquid crystal composition onto a supporting substrate and substantially removing the solvent by heat treatment or hot air drying.

<Confirmation of cooling rate>

The process for producing an optically anisotropic film of the present invention is characterized in that the cooling process is important and satisfies at least one of the following conditions (i) and (ii).

(i) a heating step for evaporating the solvent tough coating film, before cooling to room temperature, the temperature T _i (T _H> T _i> room temperature + 20 ℃) how long to keep in containing one or more times, and at a temperature T _i The holding time is more than 30 seconds each.

(ii) a heating process, a rough coating film temperature T the average cooling rate is less than 20 ℃ / minute until from _H to cool to room temperature to evaporate the solvent.

Here, in the present invention, it is necessary to confirm the cooling rate when the cooling step is (ii) the average cooling rate from the coating film temperature T _H to the room temperature is 20 ° C / min or less. The supporting substrate was placed on a hot plate set at a temperature T _H , and the surface temperature T _S1 was measured by using a contact type temperature sensor. It was confirmed that T _H and T _S1 were almost the same. Thereafter, the supporting substrate is removed from the hot plate, placed on a cooling metal plate, the surface temperature T _S2 is similarly measured, and the time t _c until the surface temperature T _{BS of the} metal plate, And the average cooling rate was calculated by (T _S2 -T _S1 ) / t _c . The change in the surface temperature of the support substrate when placed on a rubber plate instead of a metal plate was also measured and the cooling rate was calculated.

It is assumed that the temperature T _A and the temperature T _B become &quot; substantially equal &quot; to | T _A -T _B | In the present invention, "quenching" is performed when the cooling rate exceeds 20 ° C / minute, and "cooling" is performed at 20 ° C / minute or less.

Also, the cooling step includes (i) one or more times during which the coating film is maintained at a temperature T _i (T _H > T ₁ , T ₂ , T ₃ , ..., T _i ≥ room temperature + 20 ° C) And the holding time at the temperature T _i is 30 seconds or more, the condition (ii) may not be satisfied.

<Polymerization Conditions>

Under an atmosphere of nitrogen, light having an intensity of 19 mW / cm ² (365 nm) was irradiated for 26 seconds by using an ultra-high pressure mercury lamp of 250 W (Multilight-250 manufactured by Wuxi Amaru Corporation) at room temperature.

&Lt; Evaluation of orientation >

(1) Preparation of rubbed glass substrate with alignment film

Polyamic acid (Rixson aligner: PIA-5370 JNC) for low tilt angle (horizontal alignment mode) was spin-coated on a glass substrate having a thickness of 1.1 mm, and the solvent was hot-rolled from a coating film obtained by spin coating at 80 占 폚 After removal on the plate, the coating film was fired in an oven at 230 DEG C for 30 minutes, and then rubbed with a rayon cloth.

(2) Visual observation method

A substrate on which a retardation film was formed was observed between two polarizers arranged in a crossed Nicols state, and the substrate was rotated in a horizontal plane to check the contrast state. The substrate on which the retardation film was formed was observed under a polarizing microscope to confirm the presence of alignment defects.

(3) Measurement by a polarization analyzer

Using a polarization analyzer OPTIPRO manufactured by Shin-Tek Corp., light having a wavelength of 550 nm and 450 nm was irradiated to the substrate on which the retardation film was formed. And the retardation was measured while reducing the angle of incidence of these lights from 90 DEG with respect to the film surface. The retardation (retardation) is expressed as [Delta] nxd. The symbol? N is the optical anisotropy value, and the symbol d is the thickness of the optical compensation film.

&Lt; Measurement of film thickness &

The layer of the optical compensation film of the glass substrate to which the optical compensation film was attached was cut out and the step was measured using a fine shape measuring device (Alpha Step IQ manufactured by KLA TENCOR Co.).

<Evaluation of optical anisotropy (? N)

(N) = retardation (Re) / film thickness (d) from the retardation and the film thickness value when the angle of incidence of light obtained with respect to the liquid crystal film having the homogeneous orientation is 90 DEG with respect to the film surface Respectively.

&Lt; Evaluation of wavelength dispersion characteristics >

As a characteristic of the wavelength dispersion, a value obtained from the following equation was taken as an index.

Characteristics of wavelength dispersion = retardation (Re _{450 nm} ) measured with light at 450 nm / retardation (Re _{550 nm} ) measured with light at 550 nm.

That is, when the characteristic value of the wavelength dispersion is small, the low-wavelength dispersion property is high, and when the value is 1 or less, it has the reverse wavelength dispersion characteristic.

&Lt; Polymerizable liquid crystal compound &

As the polymerizable liquid crystal compounds in Examples and Comparative Examples, the following compounds were used. The aspect ratio of the molecular structure of the following compounds was calculated from the molecular model optimized by the molecular calculation method using B3LYP / 6-31G (d).

Compound (1-1-2a)

The compound (1-1-2a) is a compound (1-1-2) wherein R ⁵ is hydrogen, Y ¹ is each -O-, Q ¹ is an alkylene having 6 carbon atoms, PG is PG-1, and R &lt; ³ &gt; in PG-1 are each hydrogen.

The compound (1-1-2a) had an aspect ratio L / D of 1.98 as determined by molecular calculation.

Compound (1-1-2b)

The compound (1-1-2b) is a compound (1-1-2) wherein R ⁵ is chlorine bonded at the p-position, Y ¹ is each -O-, Q ¹ is an alkylene , PG is PG-1, and R ³ in PG-1 is hydrogen.

The compound (1-1-2b) had an aspect ratio, as determined by molecular calculation, of L / D = 1.97.

Compound (1-1-6a)

The compound (1-1-6a) is a compound (1-1-6) wherein R ⁵ is hydrogen, Y ¹ is each -O-, Q ¹ is an alkylene having 6 carbon atoms, PG is PG-1, and R &lt; ³ &gt; in PG-1 are each hydrogen.

The compound (1-1-6a) had an aspect ratio L / D of 1.96 as determined by molecular calculation.

Compound (1-1-14a)

The compound (1-1-14a) is a compound (1-1-14) wherein R ⁵ is hydrogen, Y ¹ is each -O-, Q ¹ is an alkylene having 6 carbon atoms, PG is PG-1, and R &lt; ³ &gt; in PG-1 are each hydrogen.

The compound (1-1-14a) had an aspect ratio L / D of 1.98 as determined by molecular calculation.

Compound (1-4-1a)

The compound (1-4-1a) is a compound (1-4-1) wherein R ⁴ is alkyl having 3 carbon atoms, Y ¹ is each -O-, Q ¹ is alkylene having 6 carbon atoms , PG are each PG-1, and R ³ in PG-1 is hydrogen.

In the compound (1-4-1a), two kinds of values were obtained depending on the direction of the mesogen portion and the ratio of the aspect ratio obtained by the molecular calculation was L / D = 2.09 (anti) and L / D = 1.36 (syn).

Compound (1-2-3a)

The compound (1-2-3a) is a compound (1-2-3) wherein Y ¹ is -O-, Q ¹ is an alkylene having 6 carbon atoms, PG is PG-1, PG R &lt; ³ &gt; in &lt; / RTI &gt;

The compound (1-2-3a) had an aspect ratio, as determined by molecular calculation, of L / D = 1.98.

Compound (1-3-3a)

The compound (1-3-3a) is a compound (1-2-3) wherein Y ¹ is -O-, Q ¹ is an alkylene having 6 carbon atoms, PG is PG-1, PG R &lt; ³ &gt; in &lt; / RTI &gt;

The compound (1-3-3a) had an aspect ratio, as determined by molecular calculation, of L / D = 2.00.

&Lt; Preparation of polymerizable liquid crystal composition (PLC-1) >

Compound (1-1-2a) 90 wt.%, Compound (M2-7) a = 4, R M is a mixture of hydrogen, the compound (M2-7a) polymerizable liquid crystal compounds composed of 10% by weight in the (MIX- 1) was prepared.

Next, 3 parts by weight of Irgacure 184 (trade name, manufactured by BASF Japan KK) as a polymerization initiator, and 3 parts by weight of TEGOFLOW 370 (trade name, manufactured by Evoniksha) as a surfactant were added to 100 parts by weight of the mixture (MIX- And the mixture was stirred at room temperature (25 ° C) and dissolved in cyclohexanone to prepare a solution having a concentration of (MIX-1) of 25 wt%. This solution is referred to as (PLC-1).

&Lt; Preparation of polymerizable liquid crystal compositions (PLC-2 to PLC-10)

PLC-2 to PLC-10 were prepared in the same manner as in PLC-1. The compounds and compositions used are summarized in Table 1. The compound (M2-1a) in the table is a compound in which a = 4 and R ^M is hydrogen in the compound (M2-1) and a = 6 in the compound (M1-24) And R ^M is hydrogen.

[Table 1]

[Table 2]

[Example 1]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-1) was applied onto a glass substrate with a rubbed alignment film by spin coating. This substrate was heated at T _H = 90 ° C for 1 minute and held at T ₁ = 60 ° C (≥ room temperature + 20 ° C) for 1 minute and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was in a dark field, and it was judged that the alignment was uniform. The retardation of the optically anisotropic film was measured. The result was as shown in Fig. 1, and the retardation from the vertical direction was the maximum. Therefore, it was judged to be the horizontal orientation. The film thickness was 1.9 mu m. When the phase transition point of the polymerizable liquid crystal composition (PLC-1) after the solvent removal treatment was confirmed by a polarizing microscope, the temperature (T _NI ) changing from the nematic phase to the isotropic phase was 62 ° C.

[Comparative Example 1]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-1) was applied onto a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 90 ° C for 1 minute and held at T ₁ = 40 ° C (room temperature + 20 ° C) for 1 minute and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizing plates arranged in Cross-Nicol and the area where light leakage was observed when the substrate was in the darkness state was determined and it was judged that the alignment was uneven. The film thickness was 1.9 mu m.

[Example 2]

&Lt; Case where the cooling process satisfies the above (ii)

The polymerizable liquid crystal composition (PLC-2) was applied to a glass substrate with a rubbed alignment film by spin coating. This substrate is room temperature from T _H = from 90 ℃ After heating for 1 minute at room temperature (25 ℃) thickness of about 0.6 cm rubber phase four minutes (= t _c), a T _H the temperature of the substrate and the value of the in put in (The time required for the temperature of the substrate to reach room temperature is 4 minutes, and the average cooling rate of the substrate is 16.3 DEG C / min at 20 DEG C / min or less). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of the optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged to be in the horizontal orientation. The film thickness was 1.3 mu m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 75 ° C.

[Comparative Example 2]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-2) was applied to a glass substrate with a rubbed alignment film by spin coating. This substrate is room temperature from T _H = from 90 ℃ After heating for 1 minute, room temperature, 2.5 minutes (= t _c) value, and a T _H the temperature of the substrate on the of about 1.6 cm thickness, which is put in (25 ℃) plate (The time required for the temperature of the substrate to reach room temperature was 2.5 minutes, and the average cooling rate of the substrate was more than 20 ° C / minute at 26 ° C / minute). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizing plates arranged in Cross-Nicol and the area where light leakage was observed when the substrate was in the darkness state was determined and it was judged that the alignment was uneven. The film thickness was 1.3 mu m.

[Example 3]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-3) was applied onto a glass substrate with a rubbed alignment film by spin coating. This substrate was heated at T _H = 100 ° C for 1 minute and then held at T ₁ = 60 ° C (≥ room temperature + 20 ° C) for 1 minute and placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 1.3 mu m. The phase transition point was observed in the same manner as in Example 1, and T _NI = 85 ° C.

[Comparative Example 3]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-3) was applied onto a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 100 ° C for 1 minute and then held at T ₁ = 60 ° C (≥ room temperature + 20 ° C) for 20 seconds and placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizing plates arranged in Cross-Nicol and the area where light leakage was observed when the substrate was in the darkness state was determined and it was judged that the alignment was uneven. The film thickness was 1.3 mu m.

[Example 4]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-4) was applied onto a glass substrate with a rubbed alignment film by spin coating. This substrate was heated at T _H = 80 ° C for 1 minute and held at T ₁ = 60 ° C (≥ room temperature + 20 ° C) for 1 minute and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 1.7 mu m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 65 ° C.

[Comparative Example 4]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-4) was applied onto a glass substrate with a rubbed alignment film by spin coating. This substrate is room temperature from T _H = from 80 ℃ After heating for 1 minute, room temperature for 1 minutes (= t _c) value, and a T _H the temperature of the substrate on the of about 1.6 cm thickness, which is put in (25 ℃) plate (The time required for the temperature of the substrate to reach room temperature is 1 minute, and the average cooling rate of the substrate is more than 20 ° C / minute at 55 ° C / minute). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizing plates arranged in Cross-Nicol and the area where light leakage was observed when the substrate was in the darkness state was determined and it was judged that the alignment was uneven. The film thickness was 1.7 mu m.

[Example 5]

&Lt; Case where the cooling process satisfies the above (ii)

The polymerizable liquid crystal composition (PLC-5) was applied onto a glass substrate with a rubbed alignment film by spin coating. This substrate is room temperature from T _H = at 100 ℃ After heating for 1 minute at room temperature (25 ℃) 4 bungan (= t _c) value, and a T _H the temperature of the substrate on the put rubber approximately 0.6 cm thick in (The time required for the temperature of the substrate to reach room temperature is 4 minutes, and the average cooling rate of the substrate is 18.8 DEG C / min at 20 DEG C / min or less). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic substrate was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no light leakage when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 1.2 mu m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 59 ° C.

[Comparative Example 5]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-5) was applied onto a glass substrate with a rubbed alignment film by spin coating. This substrate was heated at T _H = 100 ° C for 1 minute and held at T ₁ = 40 ° C (room temperature + 20 ° C) for 1 minute and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic substrate was inserted between two polarizers arranged in Cross-Nicol and the area where light leakage was observed when the substrate was set to the darkness state was judged to be nonuniform. The film thickness was 1.2 mu m.

[Example 6]

&Lt; Case where the cooling process satisfies the above (ii)

The polymerizable liquid crystal composition (PLC-6) was applied onto a glass substrate with a rubbed alignment film by spin coating. This substrate is room temperature from T _H = from 90 ℃ After heating for 1 minute at room temperature (25 ℃) thickness of about 0.6 cm rubber phase four minutes (= t _c), a T _H the temperature of the substrate and the value of the in put in (The time required for the temperature of the substrate to reach room temperature is 4 minutes, and the average cooling rate of the substrate is 16.3 DEG C / min at 20 DEG C / min or less). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 1.2 mu m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 71 ° C.

[Comparative Example 6]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-6) was applied onto a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 90 ° C for 1 minute and held at T ₁ = 40 ° C (room temperature + 20 ° C) for 1 minute and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizing plates arranged in Cross-Nicol and the area where light leakage was observed when the substrate was in the darkness state was determined and it was judged that the alignment was uneven. The film thickness was 1.2 mu m.

[Example 7]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-7) was applied onto a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 80 ° C for 1 minute and held at T ₁ = 60 ° C (> room temperature + 20 ° C) for 1 minute and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 2.0 m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 57 ° C.

[Comparative Example 7]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-7) was applied onto a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 80 ° C for 1 minute and held at T ₁ = 40 ° C (room temperature + 20 ° C) for 1 minute and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizing plates arranged in Cross-Nicol and the area where light leakage was observed when the substrate was in the darkness state was determined and it was judged that the alignment was uneven. The film thickness was 2.0 m.

[Example 8]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-8) was applied to a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 100 ° C for 1 minute and then held at T ₁ = 60 ° C (> room temperature + 20 ° C) for 1 minute and placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 2.0 m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 65 ° C.

[Comparative Example 8]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-8) was applied to a glass substrate with a rubbed alignment film by spin coating. This substrate was heated at T _H = 100 ° C for 1 minute and then held for 20 seconds at T ₁ = 60 ° C (> room temperature + 20 ° C). The substrate was placed on a metal plate having a thickness of about 1.6 cm, (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizing plates arranged in Cross-Nicol and the area where light leakage was observed when the substrate was in the darkness state was determined and it was judged that the alignment was uneven. The film thickness was 2.0 m.

[Example 9]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-9) was applied to a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 100 ° C for 1 minute and then held at T ₁ = 60 ° C (> room temperature + 20 ° C) for 1 minute and placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 1.7 mu m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 77 ° C.

[Example 10]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-10) was applied onto a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 100 ° C for 1 minute and then held at T ₁ = 60 ° C (> room temperature + 20 ° C) for 1 minute and placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured, and the same graph as in Example 1 was obtained. The film thickness was 1.7 mu m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 82 ° C.

[Example 11]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-11) was applied to a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 100 ° C for 1 minute and held at T ₁ = 50 ° C (> room temperature + 20 ° C) for 3 minutes and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 2.0 m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 58 ° C.

[Comparative Example 9]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-11) was applied to a glass substrate with a rubbed alignment film by spin coating. This substrate is room temperature from T _H = at 100 ℃ After heating for 1 minute, room temperature for 1 minutes (= t _c) value, and a T _H the temperature of the substrate on the of about 1.6 cm thickness, which is put in (25 ℃) plate (The time required for the temperature of the substrate to reach room temperature was 1 minute, and the average cooling rate of the substrate was more than 20 ° C / minute at 60 ° C / minute). Thereafter, the coating film from which the solvent was removed was polymerized in air by ultraviolet rays to obtain a film. When the optical anisotropy of the substrate was confirmed by observing the optical anisotropy of the substrate, the obtained film was placed between two polarizers arranged by Cross-Nicol and no anisotropic state was observed at any angle of the substrate, There was no. The film thickness was 2.0 m.

[Example 12]

&Lt; Case where the cooling process satisfies the above (i)

The polymerizable liquid crystal composition (PLC-12) was applied to a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 100 ° C for 1 minute and held at T ₁ = 50 ° C (> room temperature + 20 ° C) for 3 minutes and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent had been removed was polymerized in air by ultraviolet rays to obtain an optically anisotropic film. The resulting optically anisotropic film was placed between two polarizers arranged in Cross-Nicol and it was confirmed that there was no leakage of light when the substrate was set to darkness, and it was judged that the alignment was uniform. The retardation of this optically anisotropic film was measured. Since the same graph as in Example 1 was obtained, it was judged that the film was in the horizontal orientation. The film thickness was 2.0 m. When the phase transition point was observed in the same manner as in Example 1, T _NI = 58 ° C.

[Comparative Example 10]

&Lt; Case where the cooling process does not satisfy (i) and (ii)

The polymerizable liquid crystal composition (PLC-8) was applied to a glass substrate with a rubbed alignment film by spin coating. The substrate was heated at T _H = 100 ° C for 1 minute and held at T ₁ = 40 ° C (room temperature + 20 ° C) for 3 minutes and then placed on a metal plate having a thickness of about 1.6 cm placed at room temperature (25 ° C) (= t _c ). Thereafter, the coating film from which the solvent was removed was polymerized in air by ultraviolet rays to obtain a film. The resulting film was placed between two polarizers arranged in cross-nicol and the optical anisotropy of the substrate was confirmed. As a result, the film was not in a dark state and the orientation was uneven, so that a film having optical anisotropy could not be obtained. The film thickness was 2.0 m.

Production conditions of the optically anisotropic films produced in Examples 1 to 10 and Comparative Examples 1 to 8 are shown in Tables 3 and 4.

[Table 3]

[Table 4]

&Lt; Optical properties of optical compensation film >

(The measured value of the wavelength? Nm (Re _? ) / The measured value (Re ₅₅₀ ) of the wavelength of 550 nm) of the retardation of 90 DEG relative to the film surface of the optical compensation film prepared in Example 1 is shown in Fig. 2 Respectively.

The wavelength dispersion characteristics of the retardation of 90 DEG (measured value (Re ₅₅₀ ) at a wavelength of 450 nm / measured value (Re ₅₅₀ ) at a wavelength of 550 nm) relative to the film surface of the optical compensation film produced in Examples 1 to 12, The film thickness and? N at a wavelength of 550 nm are shown in Table 5.

[Table 5]

INDUSTRIAL APPLICABILITY The production method of the present invention makes it possible to efficiently produce an optical compensation film of good quality with uniform orientation of constituent molecules. It is also applicable to the production of an optical compensation film having excellent wavelength dispersion control characteristics. Therefore, the optical compensation film produced by the manufacturing method of the manufacturing method of the present invention can be applied to various kinds of optical components such as a retardation film, an optical compensation film, a reflection film, a selective reflection film, an antireflection film, a viewing angle compensation film, a liquid crystal orientation film, Element, an elliptically polarizing element, etc., and a display element having these films or elements.

Claims (11)

1. A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound, a photopolymerization initiator, a surfactant, and a solvent, wherein the polymerizable liquid crystal composition is applied onto a supporting substrate (substrate) An optical system including a heating step of heating the obtained coating film to a temperature T _H , a cooling step of cooling the coating film that has been subjected to the heating step to room temperature, and a polymerization step of irradiating light onto the coating film that has undergone the cooling step, In the method for producing an anisotropic film,
Wherein the polymerizable liquid crystal compound exhibits a nematic phase and has an aspect ratio (length of the major axis / minor axis length) of not more than 3,
Wherein the cooling step satisfies at least one of the following conditions (i) and (ii): &lt; EMI ID =
(i) a time period during which the coating film is maintained at a temperature T _i (T _H &_gt; T _i &gt; = room temperature + 20 ° C) at least once and at a temperature T _i is 30 seconds or more ,
(ii) the average cooling rate from the coating film temperature T _H to the room temperature is not more than 20 ° C / min. The method according to claim 1,
T _H , T _i , and T _{NI satisfy the} following conditions (a) and (b) when the polymerizable liquid crystal composition is applied on a support substrate and the phase transition temperature from the liquid crystal phase to the isotropic phase of the coating film obtained by evaporating the solvent is T _NI , And (b): &lt; EMI ID =
(a) T _H ≥ T _NI + 10 ° C
(b) T _H -10 ° C ≥T _i ≥ room temperature + 20 ° C. 3. The method according to claim 1 or 2,
T _H , T _i , and T _NI satisfy the following conditions (c) and (d), respectively:
(c) T _NI ≥ 45 ° C
(d) T _NI + 5 ° C ≥T _i ≥45 ° C. 4. The method according to any one of claims 1 to 3,
Wherein a birefringence Δn (λ) for light with a wavelength of λ nm is Δn (450) / Δn (550) ≤1.05. 5. The method according to any one of claims 1 to 4,
Wherein the polymerizable liquid crystal compound comprises at least one member selected from the group consisting of compounds represented by the following formulas (1-1) to (1-4):

In the above formulas (1-1) to (1-4)
X ¹ , X ³ and X ⁴ are each independently -O- or -S-;
X ² is -CH = or -N =;
W ¹ is an aromatic ring which may contain a hetero atom and the aromatic ring may be a single bond or -C≡C- connected to a 5-membered ring containing X ¹ and X ² , and the number of π electrons is 6 to 16 ;
W ² is a condensed ring of oxygen, sulfur, a 5-membered ring, a 6-membered ring or a 5-membered ring and a 6-membered ring;
W ³ each independently represents cyano, alkoxycarbonyl having 1 to 10 carbon atoms or alkanoyl having 1 to 10 carbon atoms, and at least one -CH ₂ - in the alkoxycarbonyl and alkanoyl is -O-, -COO -, -OCO-, -CH = CH- or -C = C-;
W ⁴ represents a divalent linking group selected from the group consisting of -CH = CH-, -C≡C-, an aromatic ring which may contain a hetero atom or a combination thereof;
R ¹ is independently a group represented by the following formula (2-1)

In the formula (2-1), A ¹ is each independently 1,4-phenylene or 1,4-cyclohexylene, and in the 1,4-phenylene, at least one hydrogen is fluorine, cyano , Formyl, trifluoroacetyl, trifluoromethyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 1 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms; Z ¹ each independently represents a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -OCH ₂ CH ₂ O-, -CH ₂ CH ₂ COO-, -OCOCH ₂ CH ₂ -, -CH ₂ CH ₂ OCO- or -COOCH ₂ CH ₂ -; m is independently an integer of 1 or 2; Y ¹ is a single bond, -O-, -COO-, -OCO- or OCOO-; Q ¹ is a single bond or alkylene having 1 to 20 carbon atoms, and at least one -CH ₂ - in the alkylene is -O-, -COO-, -OCO-, -CH = CH- or -C≡ C-; PG is a polymerizable group represented by any one of the following formulas (PG-1) to (PG-8)

In the formulas (PG-1) to (PG-8), R ³ is each independently hydrogen, halogen, methyl, ethyl or trifluoromethyl;
In the above formulas (1-1) to (1-4)
R ² is independently a group represented by the following formula (2-2)

In the formula (2-2), A ² is each independently 1,4-phenylene or 1,4-cyclohexylene, and in the 1,4-phenylene, at least one hydrogen is fluorine, An alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, or an alkanoyl group having 1 to 5 carbon atoms; Z ² is a single bond; n is independently an integer of 0 to 3; R ⁴ is selected from the group consisting of hydrogen, fluorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of 1 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms or alkoxy carbon of 1 to 20 carbon atoms Nilim. 6. The method of claim 5,
Z ¹ in the formula (2-1) is independently -COO-, -OCO-, -CH ₂ CH ₂ COO- or -OCOCH ₂ CH ₂ - and PG is represented by the formula (PG-1) Wherein the polymerizable group is a polymerizable group to be displayed. The method according to claim 5 or 6,
Wherein the polymerizable liquid crystal compound is a compound represented by the formula (1-1) or (1-3). An optically anisotropic film produced by the method for producing an optically anisotropic film according to any one of claims 1 to 7; And
Polarizer
&Lt; / RTI &gt; 8. A liquid crystal display device comprising an inner surface or an outer surface of an optically anisotropic film produced by the method for producing an optically anisotropic film according to any one of claims 1 to 7. 9. A liquid crystal display device comprising the optical element according to claim 8. An organic EL display device comprising the optical element according to claim 8.

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