JP2011008205A - Composition for producing biaxial optical anisotropic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition that easily produces an optical anisotropic film having improved heat resistance, which is useful for optical compensation of a liquid crystal display device.SOLUTION: The composition for producing a biaxial optical anisotropic film having a deformed twisted helical structure contains a polymerizable liquid crystal compound and a polymerization initiator containing an oxadiazole compound expressed by general formula (1). In general formula (1), Xrepresents a trihalomethyl group or the like; Yand Yeach represent a divalent connecting group; Band Beach represent an aromatic ring; and l, m and n each represent any integer of 0, 1 and 2. A method for producing an optical anisotropic film includes applying the liquid crystal composition on a support, subjecting the liquid crystal composition to cholesteric alignment, and irradiating the liquid crystal composition with polarized light, but not includes irradiating the composition with non-polarized light before irradiating the composition with polarized light.

Description

  The present invention relates to a composition for an optically anisotropic film, and more particularly to a composition for producing a biaxial optically anisotropic film. The present invention also relates to an optically anisotropic film produced from the composition, a method for producing the same, a liquid crystal cell substrate having the optically anisotropic film, and a liquid crystal display device.

  Various liquid crystal display devices have been proposed as liquid crystal display devices. Above all, the VA (Vertically Aligned) mode has wide contrast viewing angle characteristics in all directions as a wide viewing angle mode, and has already been widely used in television as a TV application. Has appeared. In the VA mode liquid crystal display device, optical anisotropic films having various characteristics are used for optical compensation in order to reduce light leakage and color shift that occur in an oblique direction during black display.

For example, as an optical compensation sheet that contributes to an improvement in color viewing angle characteristics of a VA mode liquid crystal display device, a retardation plate that satisfies predetermined optical characteristics is proposed, and a modified polycarbonate is used as the material thereof (Patent Document 1). reference).
In Patent Document 2, it is proposed that a biaxial film having a twisted helical structure is formed by using a liquid crystal composition containing a dichroic polymerization initiator and used for optical compensation of a liquid crystal display device. Yes. However, no polymerization initiator other than the above-mentioned dichroic polymerization initiator is known as a polymerization initiator capable of producing a deformed twisted helical structure biaxial film.

JP 2004-37837 A JP 2005-513241 A

  An object of the present invention is to provide a biaxial optically anisotropic film useful for optical compensation of a liquid crystal display device, which can easily produce an optically anisotropic film with improved heat resistance. And In particular, the present invention has an object to provide a composition that can easily produce an optically anisotropic film having improved heat resistance, which is a biaxial optically anisotropic film having a deformed twisted helical structure. To do. Another object of the present invention is to provide a method capable of easily producing a biaxial optically anisotropic film. Moreover, this invention makes it a subject to provide the liquid crystal cell and liquid crystal display device using the optically anisotropic film produced from the said composition.

Means for solving the problems are as follows [1] to [12].
[1] A polymerizable liquid crystal compound and a polymerization initiator containing an oxadiazole compound represented by the following general formula (1) for producing a deformed twisted spiral biaxial optically anisotropic film Liquid crystal composition:

式中、Ｘ¹は水素原子、ハロゲン原子、アルキル基、アルコキシ基、シアノ基、モノハロメチル基、ジハロメチル基、及びトリハロメチル基からなる群から選択される基を表し、Ｙ¹、Ｙ²はそれぞれ独立に、以下の基：

In the formula, X ¹ represents a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a cyano group, a monohalomethyl group, a dihalomethyl group, and a trihalomethyl group, and Y ¹ and Y ² are each independently And the following groups:

から選択される２価の連結基を表し、Ｂ¹、Ｂ²はそれぞれ独立に置換基を有していてもよい芳香環を表し、ｌ、ｍ、ｎはそれぞれ独立に０、１、２から選択されるいずれかの整数を表す。

Represents a divalent linking group selected from: B ¹ and B ² each independently represent an aromatic ring optionally having a substituent, and l, m and n are each independently 0, 1, 2 Represents any integer selected.

[2] The liquid crystal composition according to [1], comprising at least one polymerizable liquid crystal compound having two or more polymerizable groups.
[3] The liquid crystal composition according to [2], wherein the ratio of the polymerizable liquid crystal compound having two or more polymerizable groups to the total mass of the liquid crystal compound is 75% by mass or more.
[4] An optically anisotropic film formed by irradiating polarized light to the liquid crystal composition according to any one of [1] to [3].
[5] The optically anisotropic film according to [4], wherein the cholesteric pitch of the helical structure is 80 nm or more and 230 nm or less.

[6] A color filter substrate having a substrate and the optically anisotropic film according to [4] or [5].
[7] A substrate for a liquid crystal cell comprising a substrate and the optically anisotropic film according to [4] or [5].
[8] A liquid crystal display device having the optically anisotropic film according to [4] or [5].
[9] The liquid crystal display device according to [8], which is a VA mode liquid crystal display device.
[10] The liquid crystal display device according to [8] or [9], wherein the liquid crystal cell has an optically anisotropic film.
[11] The liquid crystal display device according to [10], wherein the optically anisotropic film is disposed in each region corresponding to each pixel in the liquid crystal cell.
[12] A method for producing a biaxial optically anisotropic film, wherein the liquid crystal composition according to any one of [1] to [3] is applied to a support, and the liquid crystal composition is cholesteric. An optically anisotropic film characterized by comprising an alignment step and then irradiating the liquid crystal composition with polarized light, and not including a step of irradiating non-polarized light before the step of irradiating the polarized light. Method.
[13] The production method according to [12], wherein the oxygen concentration in the step of irradiating polarized light is 10% or more and 21% or less.

  The present invention provides a composition capable of easily producing a biaxial optically anisotropic film having improved heat resistance. The optically anisotropic film formed through the step of irradiating the composition of the present invention with polarized light has biaxial optical anisotropy and is useful for optical compensation of liquid crystal display devices such as VA mode liquid crystal display devices. It is.

It is the schematic for demonstrating an example of the manufacturing method of the liquid crystal cell which has the optically anisotropic film | membrane of this invention inside. It is a schematic sectional drawing which shows an example of the liquid crystal cell which has the board | substrate for liquid crystal cells of this invention. It is a schematic sectional drawing which shows an example of the liquid crystal display device of this invention.

Hereinafter, the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
Further, in this specification, the term “polymer” is used to include not only a polymer composed of one type of monomer but also a so-called copolymer composed of two or more types of monomers.

In addition, in this specification, when saying “may have a substituent” for a certain functional group, it indicates that the functional group may have one or more substituents, Unless otherwise specified, the number, position, and type of substituents to be bonded are not particularly limited. When a certain functional group has two or more substituents, they may be the same or different. Moreover, when a substituent is illustrated, the illustrated substituent may be further substituted by the same or another illustrated substituent.

In this specification, when referring to an “alkyl group”, a linear or branched alkyl group may be used unless otherwise specified, and an alkyl group having 1 to 12 carbon atoms is preferable, and 1 to 8 carbon atoms is preferable. The alkyl group is more preferable. The same applies to other groups containing an alkyl group (for example, an alkoxy group, an alkoxycarbonyl group, a hydroxyalkyl group, etc.).
In the present specification, the term “halogen atom” may be any of fluorine, chlorine, bromine, or iodine.

In this specification, Re (λ) and Rth (λ) each represent in-plane retardation (nm) and retardation in the thickness direction (nm) at wavelength λ. In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments). When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (if there is no slow axis, any in-plane film The light of wavelength λ nm is incident from each of the inclined directions in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction (with the direction of the rotation axis as the rotation axis). KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value. In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative. In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (11) and (12).

注記：上記のＲｅ（θ）は法線方向から角度θ傾斜した方向におけるレターデーション値を表し、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘ及びｎｙに直交する方向の屈折率を表す。ｄは膜厚を表す。

Note: Re (θ) represents the retardation value in the direction inclined by the angle θ from the normal direction, nx represents the refractive index in the slow axis direction in the plane, and ny is the direction orthogonal to nx in the plane. Nz represents the refractive index in the direction orthogonal to nx and ny. d represents a film thickness.

When the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film without a so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) and the tilt axis (rotating axis). In each of the 10 degree steps, light of wavelength λ nm is incident from the inclined direction and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or WR is calculated. In the above measurement, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59).
KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumed average refractive index and the film thickness.

  Also, the sign of Rth is when the phase difference measured by injecting light having a wavelength of 550 nm from the direction inclined + 20 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis) exceeds Re Is positive and negative is below Re. However, in a sample with | Rth / Re | of 9 or more, it was tilted by + 40 ° with respect to the film normal direction with the in-plane fast axis as the tilt axis (rotation axis) using a polarizing microscope with a free rotation base. In the state, the case where the slow axis of the sample which can be determined using the polarizing plate inspection plate is parallel to the film plane is positive, and the case where the slow axis is in the thickness direction of the film is negative.

  In the present specification, “substantially” for the angle means that the error from the exact angle is within a range of less than ± 5 °. Further, the error from the exact angle is preferably less than 4 °, more preferably less than 3 °. With regard to retardation, “substantially” means that the retardation is within ± 5%. Further, Re is not 0 means that Re is 5 nm or more. Further, the refractive index measurement wavelength indicates a wavelength of 550 nm unless otherwise specified. In this specification, “visible light” refers to light having a wavelength of 400 nm to 700 nm.

1. TECHNICAL FIELD The present invention relates to a liquid crystal composition capable of easily forming a biaxial optically anisotropic film. Specifically, the present invention relates to a liquid crystal composition capable of forming an optically anisotropic film having a deformed twisted helical structure. The optically anisotropic film having a deformed twisted helical structure means an optically anisotropic film containing an optically anisotropic material having a deformed twisted helical structure. Here, the optically anisotropic material may be a polymerizable material that can usually form a cholesteric structure. In the present invention, such a material is a polymerizable liquid crystal compound and an oxadiazole represented by the general formula (1). A liquid crystal composition containing a polymerization initiator containing a compound is used. An optically anisotropic film can be formed by subjecting the composition to a cholesteric orientation (referred to a state of being oriented in a cholesteric arrangement), followed by a polymerization reaction by irradiation with polarized light. The formed optically anisotropic film exhibits a phase difference caused by deformation of the helical structure, that is, optical biaxiality, and is useful for optical compensation of liquid crystal display devices, particularly VA mode liquid crystal display devices. It is.
In the present specification, the “optically anisotropic film” may be referred to as an “optically anisotropic layer” when provided on a support.
Hereinafter, the components of the liquid crystal composition of the present invention and the method for producing an optical anisotropic film using the liquid crystal composition of the present invention will be described.

1-1. Oxadiazole Compound The liquid crystal composition of the present invention contains an oxadiazole compound as a polymerization initiator. The present inventors show that the liquid crystal composition containing an oxadiazole compound represented by the following general formula (1) exhibits a preferable optical biaxiality by polarized light irradiation, as shown in the Examples below. It has been found that a conductive film is formed. Since the oxadiazole compound represented by the following general formula (1) exhibits high polymerization reactivity in a normal air atmosphere, an optically anisotropic film with improved heat resistance can be formed.

In General Formula (1), X ¹ represents any of a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a cyano group, a monohalomethyl group, a dihalomethyl group, or a trihalomethyl group. X ¹ is more preferably a monohalomethyl group, a dihalomethyl group, or a trihalomethyl group, and even more preferably a trihalomethyl group.
Y ¹ and Y ² each independently represent any of the following divalent linking groups.

Among these, Y ¹ and Y ² are more preferably an ethenylene group, an ethynylene group, or an amide divalent linking group, and more preferably an ethenylene group or an amide divalent linking group.

B ¹ and B ² each independently represents an aromatic ring which may have a substituent. The aromatic ring may be a heterocyclic ring. Examples of the substituent include substituents such as a halogen atom, a cyano atom, an alkyl group, an alkoxy group, a hydroxy group, an alkyl ester group, an alkylamide group, and an aryl group (preferably an aryl group having 6 to 10 carbon atoms). It is done. The aromatic ring is preferably a benzene ring, B ¹ is preferably a 1,4-phenylene group, and B ² is preferably a phenyl group.

L, m, and n each independently represent an integer of 0, 1, or 2.

The oxadiazole compound represented by the general formula (1) can be synthesized, for example, by the method described in US Pat. No. 4,221,970.
Specific examples of the compound represented by the general formula (1) are given below, but the present invention is not limited to the following specific examples.

1-2. Liquid Crystal Compound The liquid crystal composition of the present invention contains at least one polymerizable liquid crystal compound. In general, liquid crystal compounds can be classified into rod-like liquid crystal compounds and discotic liquid crystal compounds based on their shapes, but in the present invention, rod-like liquid crystal compounds are preferably used. The liquid crystal compound may be a mixture of two or more types of liquid crystal compounds, but in order to have excellent heat resistance, it should contain at least one polymerizable liquid crystal compound having two or more polymerizable groups in one liquid crystal molecule. Further preferred. Two or more polymerizable groups in the polymerizable liquid crystal compound having two or more polymerizable groups may be the same as or different from each other.
Examples of the polymerizable group are shown below.

As the polymerizable group, an acryloyl group is particularly preferable.
In the liquid crystal composition of the present invention, the ratio of the polymerizable liquid crystal compound having two or more polymerizable groups to the total mass of the liquid crystal compound contained is preferably 75% by mass to 100% by mass, and 80% by mass to More preferably, it is 100 mass%.

  In addition, the liquid crystal compound used for this invention should just be a liquid crystal compound which can cholesterically align in presence of an optically active compound. At this time, the liquid crystal compound itself does not need to be an optically active substance, and an achiral liquid crystal compound can be used. In the present invention, it is preferable to use an achiral liquid crystal compound from the viewpoint of easy control of expression of optical characteristics in the process of producing an optically anisotropic film. From the same viewpoint, in the present invention, it is preferable to use a liquid crystal compound that does not contain a functional group such as a photoisomerization group or a photodimerization group.

  Not only low-molecular liquid crystal compounds but also high-molecular liquid crystal compounds can be used. The polymer liquid crystal compound may be a polymer compound obtained by polymerizing a rod-like liquid crystal compound having a low molecular polymerizable group.

As the rod-like liquid crystal compound, for example, the rod-like liquid crystal compound described in paragraphs [0065] to [0071] of JP-A-2009-69793 can be used.
Examples of rod-like liquid crystal compounds are shown below.

  Among the above exemplified compounds, I-1, I-2, I-3, I-10, I-11, or I-12 is preferable, and I-2 is particularly preferable.

1-3. Chiral agent In order to form cholesteric alignment, it is preferable to add a chiral agent to the liquid crystal composition. The cholesteric pitch of the obtained cholesteric orientation can be adjusted by the kind and addition amount of the chiral agent. In order to reduce the cholesteric pitch, it is necessary to select a chiral agent having as much helical twisting power as possible and increase the amount of the chiral agent added. In order to be able to add a large amount of the chiral agent, it is preferable that the chiral agent has at least one polymerizable group. As the polymerizable group, an ethylenically unsaturated group is preferable, and an acryloyloxy group and a methacryloyloxy group are particularly preferable. Specifically, the chiral agent described in EP1388538 A1 page 16, 17 can be preferably used.

1-4. Preparation of Liquid Crystal Composition In the liquid crystal composition of the present invention, the content of the oxadiazole compound represented by the general formula (1) is the total mass of the liquid crystal composition (such as a coating liquid, in an aspect including a solvent, The total solid content excluding the solvent is preferably 0.01% by mass to 20% by mass, and more preferably 0.5% by mass to 8% by mass.

  The content of the liquid crystal compound is 60% by mass to 95% by mass with respect to the total mass of the liquid crystal composition (in the case of an application liquid or the like, including the solvent, the total mass of the solid content excluding the solvent). Preferably, it is 70 mass%-90 mass%.

  The content of the chiral agent is 5% by mass to 40% by mass with respect to the total mass of the liquid crystal composition (the total mass of the solid content excluding the solvent in a mode including a solvent such as a coating liquid). Preferably, it is 10 mass%-30 mass%. When two or more chiral agents are used, the total is preferably within the above range. When the content of the chiral agent is less than 10% by mass, the reflection wavelength becomes visible, and the optically anisotropic film may be colored. Moreover, when content of the said chiral agent exceeds 30 mass%, it may not be in a cholesteric orientation state.

1-5. Other Additives In addition to the oxadiazole compound represented by the general formula (1), the liquid crystal compound, and the chiral agent optionally contained, the liquid crystal composition of the invention includes an aligning agent and the general formula ( An additive such as a polymerizable initiator other than the oxadiazole compound represented by 1) may be contained.
Alignment agent:
The liquid crystal composition of the present invention may contain an aligning agent for improving the alignment of the liquid crystal compound. For example, by containing at least one compound represented by the general formulas (1) to (3) described in [0068] to [0072] of JP-A-2007-121986, the liquid crystal compound is substantially horizontal. It can be oriented, and a stable cholesteric orientation can be obtained by using it together with the chiral agent.

  The addition amount of the aligning agent is 0.01% by mass to 20% by mass with respect to the total mass of the liquid crystal composition (in the aspect including a coating liquid or the like, the total mass of the solid content excluding the solvent). Is preferable, 0.01 mass% to 10 mass% is more preferable, and 0.02 mass% to 1 mass% is particularly preferable. An orientation agent may be used independently and may use 2 or more types together.

Polymerization initiator:
The liquid crystal composition of the present invention may contain a compound other than the oxadiazole compound represented by the general formula (1) as a polymerization initiator. The oxadiazole compound represented by the general formula (1) functions as a radical photopolymerization initiator, but may contain other initiators and sensitizers, for example, for controlling the polymerization reaction.
For example, the liquid crystal composition of the present invention may contain a photocationic initiator that generates cationic species by light. As the photocation initiator to be employed, a general sulfonium salt photocation initiator or an iodonium salt photocation generator can be used. Specifically, a commercially available photocationic initiator, cyclic UVI-6990 (manufactured by Dow Chemical), cyclic UVI-6974 (manufactured by Dow Chemical), Adekaoptomer SP-150 (manufactured by Adeka), Adekaoptomer SP-152 ( Adeka), Adekaoptomer SP-170 (Adeka), Irgacure 250 (Ciba Japan) and the like can be used.

For example, the liquid crystal composition of the present invention may contain a thermal acid generator that generates an acid by heat. The thermal acid generator is a compound that generates an acid by heat, and is usually a compound having a thermal decomposition point in the range of 100 ° C. to 2300 ° C., preferably 150 ° C. to 250 ° C., for example, sulfonic acid by heating, It is a compound that generates a low nucleophilic acid such as carboxylic acid or disulfonylimide. It is preferable that the thermal acid generator is not decomposed during the storage time or in the drying step or the aging step after applying the liquid crystal composition, but rapidly decomposes in the heat curing step after the deformation of the cholesteric alignment. Accordingly, the thermal decomposition point is preferably 100 ° C to 300 ° C, more preferably 120 ° C to 250 ° C, and still more preferably 150 ° C to 250 ° C.
As the thermal acid generator, a photoacid generator that generates an acid upon exposure can be applied. For example, N-hydroxyimide sulfonate compound, benzene sulfonate, etc. can be mentioned.
Specifically, a commercially available thermal acid generator, NB-201 (Midori Chemical), SI-101 (Midori Chemical), PI-105 (Midori Chemical), etc. can be used.

  The liquid crystal composition of the present invention may contain a photosensitizer as a sensitizer. Specific examples include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone, and thioxanthone.

1-6. Solvent The liquid crystal composition of the present invention is preferably prepared as a coating solution. As a solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of the organic solvent include amides (eg, N, N-dimethylformamide); sulfoxides (eg, dimethyl sulfoxide); heterocyclic compounds (eg, pyridine); hydrocarbons (eg, benzene, hexane); alkyl halides (eg, chloroform, dichloromethane); Esters (eg, methyl acetate, butyl acetate); ketones (eg, acetone, methyl ethyl ketone); ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane); 1,4-butanediol diacetate, and the like. Among these, alkyl halides and ketones are particularly preferable. Two or more organic solvents may be used in combination.

2. Method for producing optically anisotropic film The liquid crystal composition of the present invention is applied to the surface of a support such as a glass substrate, the liquid crystal molecules in the liquid crystal composition are cholesterically aligned, and then irradiated with polarized light to produce biaxial optics. An anisotropic film can be formed.
The liquid crystal composition can be applied by various conventionally known methods. As will be described later, when an optically anisotropic film is arranged in a liquid crystal cell and is formed for each region corresponding to each pixel, it is applied to the support surface in each pixel by using an ink jet method. Is preferred.

  In order to cholesterically align the liquid crystal molecules, the coating film may be dried after the liquid crystal composition is applied to the surface. Along with the evaporation of the solvent, for example, the molecules of the achiral liquid crystal compound coexisting with each other are cholesterically aligned by the twisting force of the chiral agent. If desired, after drying, heat aging may be performed in the liquid crystal phase temperature range for 1 to 5 minutes.

  An optically anisotropic film having in-plane retardation Re can be formed by applying and drying the liquid crystal composition of the present invention as described above and then irradiating it with polarized light. This polarized light irradiation may be performed simultaneously with the photopolymerization process in the above-described orientation fixing, or may be further fixed by non-polarized light irradiation after first polarized light irradiation, or may be fixed first by non-polarized light irradiation. After that, irradiation with polarized light may be performed. In order to obtain a large retardation, it is preferable to irradiate polarized light alone or first. For polarized light irradiation, ultraviolet polarized light irradiation is preferable, and polarized light irradiation having a peak at 365 nm is particularly preferable.

The irradiation energy of polarized light irradiation is preferably 20 mJ / cm ^{2 to} 10 J / cm ² , and more preferably 100 mJ / cm ^{2 to} 800 mJ / cm ² . The illuminance is preferably ^{20mW / cm 2 ~1000mW / cm 2} , more preferably ^{50mW / cm 2 ~500mW / cm 2} , and particularly preferably ^{100mW / cm 2 ~350mW / cm 2} . The irradiation wavelength preferably has a peak at 300 nm to 450 nm, and more preferably has a peak at 350 nm to 410 nm.

  In order to control the polymerization reaction, the oxygen concentration at the time of irradiation with polarized light may be adjusted. In order to adjust the oxygen concentration, means such as nitrogen purge can be taken. The oxygen concentration is preferably 10% or more and 21% or less. In consideration of work safety, 18% to 21% is more preferable.

When heated after irradiation with polarized light, crosslinking proceeds further, and a larger in-plane retardation can be obtained.
The heating temperature is preferably 50 ° C to 250 ° C, more preferably 50 ° C to 200 ° C, and particularly preferably 70 ° C to 170 ° C.

In the method of the present invention, the step of irradiating non-polarized light is not included before the step of irradiating polarized light. Thereby, an in-plane phase difference can be fully expressed. In addition, after irradiating polarized light, it is preferable to further irradiate with light for improving heat resistance. The light irradiation for improving the heat resistance after the polarized light irradiation may be polarized light irradiation or non-polarized light irradiation. The light irradiation energy for curing is preferably 20 mJ / cm ^{2 to} 10 J / cm ² , and more preferably 100 mJ / cm ^{2 to} 800 mJ / cm ² . The illuminance is preferably ^{20mW / cm 2 ~1000mW / cm 2} , more preferably ^{50mW / cm 2 ~500mW / cm 2} , and particularly preferably ^{100mW / cm 2 ~350mW / cm 2} . In the case of polarized light irradiation, the irradiation wavelength preferably has a peak at 300 nm to 450 nm, and more preferably 350 nm to 410 nm. In the case of non-polarized light irradiation, it preferably has a peak at 200 nm to 450 nm, and more preferably has a peak at 250 nm to 410 nm.

  The thickness of the optically anisotropic film of the present invention is preferably 0.1 μm to 20 μm, and more preferably 0.5 μm to 10 μm.

3. Optical Characteristics of Optical Anisotropic Film Since the optical anisotropic film formed from the liquid crystal composition of the present invention exhibits in-plane retardation, it can satisfy, for example, characteristics required for a biaxial film.
Since the optically anisotropic film formed from the liquid crystal composition of the present invention has biaxiality, it is particularly suitable for optical compensation of a VA mode liquid crystal display device. Biaxial films are generally understood to have different nx, ny and nz. As an example, a material exhibiting optical characteristics satisfying nx>ny> nz can be mentioned. The optically anisotropic film of the present invention has a Re (550) of about 20 to 300 nm and an Nz value (where Nz = Rth (550) / Re (550) +0.5) is 1.1 to 7. It can function as a biaxial film exhibiting properties of about zero. That is, the optically anisotropic film of the present invention can be used for optical compensation of a liquid crystal display device as an alternative to a conventionally used biaxial film, and particularly used for optical compensation of a VA mode liquid crystal display device. Suitable for When the optically anisotropic film of the present invention is used as a biaxial film (for example, for optical compensation of a VA mode liquid crystal display device), Nz is preferably 1.5 to 8.0. More preferably, it is 0.0 to 7.0.
The in-plane retardation Re (550) at a wavelength of 550 nm is preferably 20 nm to 300 nm, more preferably 20 nm to 200 nm, and particularly preferably 20 nm to 100 nm. Note that Re is a parameter indicating that a larger value indicates higher biaxiality. On the other hand, the Nz factor is a parameter indicating that the smaller the value, the higher the biaxiality. The Re (550) of the biaxial optically anisotropic film necessary for compensation of the VA mode liquid crystal display device is about 50 nm, and if it deviates from the appropriate Re and Nz factors, the viewing angle dependency may decrease. is there.

  The optically anisotropic film of the present invention is preferably substantially transparent to light having a reflection wavelength of less than 400 nm and a wavelength of 380 to 780 nm. The transparency of the optically anisotropic film is determined by the refractive index of the liquid crystal material used and the pitch of the helix. The pitch of the helix is proportional to the amount of chiral agent added, and if it is added in a large amount, the pitch also increases. Since the reflection wavelength is the product of the refractive index of the liquid crystal material and the pitch of the helix, the value of the reflection wavelength can be determined by adjusting the amount of chiral agent added according to the refractive index of the liquid crystal material.

The cholesteric pitch of the optically anisotropic layer is preferably 230 nm or less and 80 nm or more, more preferably 210 nm or less and 80 nm or more, and most preferably 200 nm or less and 80 nm or more.
When the cholesteric pitch exceeds 230 nm, part of the UV irradiation light including light with wavelengths of 365 nm and 405 nm is selectively reflected, leading to insufficient curing of the optically anisotropic layer and a decrease in biaxiality. There is. If the cholesteric pitch is further increased, the optically anisotropic layer may be colored by becoming a selective reflection region of visible light, and a transparent optically anisotropic layer may not be obtained. If the cholesteric pitch is 80 nm or less, precipitates are likely to be generated in the optically anisotropic layer, which may make it difficult to produce. Furthermore, if the cholesteric pitch is increased, light leakage in black display increases, and as a result, the contrast may deteriorate.

The cholesteric pitch can be adjusted by the type and amount of the chiral agent. In order to reduce the cholesteric pitch, a chiral agent having as large helical twisting power (HTP) as possible can be selected and / or chiral. What is necessary is just to increase the additive amount. Examples of chiral agents include chiral compounds described in JP-T-2005-513241.

4). Applications of optically anisotropic film 4-1. In-cell optical anisotropic film By using the liquid crystal composition of the present invention, it is possible to express desired optical characteristics by irradiation with polarized light without using an alignment film. This is advantageous for formation, and particularly for formation in a region corresponding to each pixel in the liquid crystal cell.
In the aspect formed in the liquid crystal cell, it is preferable that the optical characteristics of the optical anisotropic film are adjusted to optical characteristics that are optimal for viewing angle compensation when R light, G light, and B light are incident. . That is, the optical anisotropic film formed in the region corresponding to the R layer of the color filter layer is optimally adjusted for viewing angle compensation when R light is incident, and corresponds to the G layer. The optical characteristics of the optical anisotropic film formed in the region are optimally adjusted for the viewing angle compensation when G light is incident, and the optical characteristics of the optical anisotropic film formed in the region corresponding to the B layer Is preferably adjusted optimally for viewing angle compensation when B light is incident. The optical characteristics of the optically anisotropic film can be adjusted to a preferable range depending on, for example, the type of the liquid crystal compound and the chiral agent, the type of the alignment control agent or the addition amount thereof, the film thickness, and the polarization irradiation conditions. .
Further, the optical anisotropic film itself may function as a color filter. In that case, R color, G color and B color pigments are added to the composition for forming an optically anisotropic film.

  As an example of a method for forming the optically anisotropic film on the surface of the liquid crystal cell substrate for each region corresponding to each pixel using the liquid crystal composition of the present invention, there is a method using an inkjet method. More specifically, a fluid containing the liquid crystal composition is applied in an ink jet method in a region separated by a black matrix, and then desired optical properties are exhibited by irradiation with polarized light, followed by heat aging as desired. Can be produced.

Hereinafter, an example of a method for manufacturing a liquid crystal cell having an optically anisotropic film therein will be described in detail with reference to FIG.
On a transparent substrate 11 made of glass or the like, for example, a negative black matrix resist material is used, and a black matrix 12 (partition) of a dot pattern is formed using a photolithography method, and a plurality of fine regions separated by the partition 12 a is formed (FIG. 1A). In the formation of the black matrix 12, there is no particular limitation on the black matrix forming material and the forming process, and there is no problem if a black matrix pattern can be formed even by a method other than a method using a photolithography method using a resist material. . The pattern of the black matrix 12 is not limited to the dot pattern, and the arrangement of the color filters to be formed is not particularly limited, and may be any of dot arrangement, stripe arrangement, mosaic arrangement, delta arrangement, and the like.

The black matrix 12 is preferably subjected to plasma treatment with a gas containing F atoms (CF ₄ or the like) after pattern formation, and the surface thereof is subjected to ink repellent treatment. In addition to the plasma treatment, the black matrix 12 may be made to contain an ink repellant in the black matrix material, or the black matrix may be formed from a material that exhibits ink repellency with respect to the glass substrate 11. May be.

  Next, a fluid 13 ′ containing the liquid crystal composition is ejected by using an ink jet device to a fine area a separated by a black matrix 12 that has been subjected to an ink repellent treatment, if desired. A layer made of (FIG. 1B) is formed. After the discharge of the solution is completed, cholesteric alignment is performed by heat aging, and irradiation with polarized light distorts the helical structure, develops in-plane anisotropy, and forms an optically anisotropic film 13 (FIG. 1). (C)). Heating may be performed as desired before irradiation with polarized light, during irradiation with polarized light, or after irradiation with polarized light. In that case, a heating device may be used.

  On the first optically anisotropic film 13 formed in this way, a second ink discharge is performed with the color filter ink liquid 14 '(FIG. 1 (d)), this is dried, and desired The second color filter layer 14 is formed by exposure or the like ((e)).

  There are no particular restrictions on the ejection conditions of the ink or the like when forming the optically anisotropic film 13 and the color filter layer 14, but the viscosity of the fluid for forming the optically anisotropic film or the ink for forming the color filter layer is high. It is preferable from the viewpoint of ejection stability that the ink is ejected at a reduced ink viscosity at room temperature or under heating (for example, 20 ° C. to 70 ° C.). It is preferable to keep the temperature of the ink or the like as constant as possible because the viscosity variation of the ink or the like greatly affects the droplet size and the droplet ejection speed as it is and causes image quality degradation.

  The inkjet head (hereinafter also simply referred to as a head) is not particularly limited, and various known ones can be used. Continuous type and dot on demand type can be used. Among the dot-on-demand types, the thermal head is preferably a type having an operation valve as described in JP-A-9-323420 for discharging. In the piezo head, for example, heads described in European Patent A277,703, European Patent A278,590 and the like can be used. The head preferably has a temperature control function so that the temperature of the composition can be controlled. It is preferable to set the injection temperature so that the viscosity at the time of injection is 5 mPa · s to 25 mPa · s, and to control the composition temperature so that the fluctuation range of the viscosity is within ± 5%. Further, the drive frequency is preferably 1 kHz to 500 kHz.

The formation order of the optical anisotropic film 13 and the color filter layer 14 may be switched, that is, the optical anisotropic film 13 may be laminated on the color filter layer 14. . Such an embodiment can be produced by switching the order of the step of forming the optical anisotropic film 13 and the step of forming the color filter layer 14 in the above manufacturing method example.
Further, the liquid crystal composition may be mixed and used in color filter forming ink.

  The optical anisotropy film 13 may be formed using fluids such as the same kind of solution, and has an optimal optical anisotropy according to the hue of the color filter layer 14 formed thereon. It may be formed using fluids containing different materials and / or different amounts in order to develop. In the case of using different solutions depending on the hue of the color filter layer at the time of forming the optical anisotropic film 13, the respective solutions may be discharged and then dried at the same time. A drying process may be performed. Further, when forming the color filter layer 14, for example, after all ink liquids for forming the R layer, the G layer, and the B layer are ejected, drying may be performed at the same time. A drying process may be performed. Further, the color of the color filter is not necessarily limited to the three colors of red, green, and blue, and may be a multi-primary color filter.

  In this manner, after forming the optical anisotropic film and the color filter layer for each region separated by the black matrix 12 corresponding to each pixel of the first substrate, the first substrate, The substrate is pasted together. Before the bonding, a transparent electrode layer and / or an alignment layer may be formed on the color filter layer 14. For example, as described in Japanese Patent Application Laid-Open No. 11-248921 and Japanese Patent No. 3255107, a base is formed by overlapping colored resin compositions forming a color filter, a transparent electrode is formed thereon, and further necessary Accordingly, it is preferable from the viewpoint of cost reduction that the spacers are formed by overlapping the protrusions for split orientation.

  A liquid crystal cell can be manufactured by injecting a liquid crystal material into a space between the opposing surfaces of the first substrate and the second substrate to form a liquid crystal layer. The first substrate is preferably arranged with the surface on which the optically anisotropic film and the color filter layer are formed on the inside, that is, the opposing surface. Then, a polarizing plate, an optical film, etc. are each affixed on the outer surface of both substrates, and a liquid crystal display device can be produced.

  In the example of the manufacturing method, when the liquid for forming the optical anisotropic film and the ink liquid for forming the color filter layer are arranged at predetermined positions, a black matrix as a partition is formed, and then an inkjet method is used. Therefore, the optically anisotropic film and the color filter layer can be accurately formed in a predetermined region on the first substrate. Therefore, it can be manufactured with a small number of steps without complicating the structure.

  In the above method, the example in which the optically anisotropic film and the color filter layer are formed in each fine region by using ink ejection by the ink jet method has been described. However, for example, a printing method other than the ink jet method is used. May be formed.

4-2. One aspect of a liquid crystal cell substrate including an optically anisotropic film formed from the liquid crystal composition of the present invention includes a substrate, an optically anisotropic film for compensating a viewing angle of the liquid crystal cell, and a color filter layer. The optically anisotropic film is used for compensating the viewing angle of the liquid crystal cell according to the hue of the color filter layer disposed below or on the optically anisotropic film (for each color of R, G, B, for example). This is a liquid crystal cell substrate having optimum optical characteristics. The substrate material is not particularly limited as long as it is transparent, and for example, a metallic support, a metal-bonded support, glass, ceramic, a synthetic resin film, or the like can be used. The birefringence is preferably small, and glass, a low birefringence polymer and the like are preferable. In addition, on the surface of the substrate, an alignment film having an alignment regulating ability with respect to the liquid crystal material and a transparent electrode layer may be formed.

  The substrate for the liquid crystal cell has a second surface opposite to the side opposite to the side on which the optically anisotropic film is formed (the surface on the side arranged outside the liquid crystal cell when incorporated in the liquid crystal display device). You may have an optically anisotropic film. The second optical anisotropic film contributes to optical compensation of the liquid crystal cell together with the optical anisotropic film of the present invention disposed in the liquid crystal cell. The preferable range of the optical characteristics of the second optical anisotropic film varies depending on the mode of the liquid crystal display device used. For example, when a liquid crystal cell substrate for VA mode is used, an optical anisotropic film formed from the liquid crystal composition of the present invention is disposed on the inner surface of the substrate, and the second optical anisotropy is formed on the outer surface of the substrate. A membrane may be placed.

FIG. 2 shows a schematic cross-sectional view of an example of a liquid crystal cell having the liquid crystal cell substrate.
The liquid crystal cell substrate shown in FIG. 2A has a pattern-like shape in which a black matrix 22 is formed as a partition on a transparent substrate 21 and is discharged by an inkjet method into a fine region separated by the partition. A color filter layer 23 and an optical anisotropic film 27 are formed. Furthermore, a transparent electrode layer 25 and an alignment layer 26 are provided thereon. Although FIG. 2 shows an embodiment in which the R, G, B color filter layers 23 are formed, a color filter layer composed of R, G, B, W (white) layers may be formed. The optically anisotropic film 27 is divided into r, g, and b regions and has optimum retardation characteristics for the hues of the R, G, and B filter layers 23, respectively.

  Further, as shown in FIG. 2B, a second optical anisotropic film 24 that contributes to optical compensation together with the optical anisotropic film 27 may be disposed on the outer surface of the liquid crystal cell substrate. The second optical anisotropic film 24 may be arranged on the same color filter side substrate side as the optical anisotropic film 27 in the cell, or may be arranged on the counter substrate side although not shown. In general, a driving electrode such as a TFT array is often arranged on the counter substrate side, and may be arranged at any position on the counter substrate. However, in the case of an active drive type having a TFT, optical anisotropy is provided. From the heat resistance of the conductive film, it is preferably higher than the silicon layer.

4-3. Liquid crystal display device In the liquid crystal display device, the optically anisotropic film formed from the liquid crystal composition of the present invention may be disposed in the liquid crystal cell as described above, or outside the liquid crystal cell, You may arrange | position between a liquid crystal cell and a polarizer. Moreover, you may further have the 2nd optical anisotropic film which contributes to optical compensation with the optical anisotropic film of this invention.
FIG. 3 is a schematic cross-sectional view of an example of a liquid crystal display device.
3 (a) and 3 (b) use the substrates of FIGS. 2 (a) and 2 (b) as upper substrates, respectively, and a glass substrate 21 having a transparent electrode layer 25 with TFT 32 and an alignment layer 26 thereon. Is a liquid crystal display device having a liquid crystal cell 37 with a liquid crystal 31 interposed therebetween. On both sides of the liquid crystal cell 37, a polarizing plate 36 made of a polarizing layer 33 sandwiched between protective layers 34 and 35 made of a cellulose acetate (TAC) film or the like is disposed. The protective layer 35 on the liquid crystal cell side may be a polymer film such as a TAC film that satisfies optical characteristics as an optical compensation sheet, or may be made of the same polymer film as the protective layer 34. Although not shown in the drawing, in the aspect of the reflective liquid crystal display device, only one polarizing plate is required on the observation side, and a reflective film is provided on the back surface of the liquid crystal cell or on the inner surface of the lower substrate of the liquid crystal cell. Of course, a front light can be provided on the liquid crystal cell observation side. Further, a transflective type in which a transmissive portion and a reflective portion are provided in one pixel of the display device is also possible. The display mode of the present liquid crystal display device is not particularly limited, and can be used for all transmissive, transflective, and reflective liquid crystal display devices. Among them, the optically anisotropic film formed from the liquid crystal composition of the present invention is effective for a VA mode liquid crystal display device in which improvement in color viewing angle characteristics is desired.

  An example of a liquid crystal display device in which an optically anisotropic film formed from the liquid crystal composition of the present invention is preferably used is a VA mode liquid crystal display device. As a VA mode liquid crystal display device, a system using a negative C-plate and an A-plate for optical compensation and a system using a biaxial film for optical compensation are known. The optically anisotropic film of the present invention can be used as a biaxial film.

In the above, an example of a VA mode liquid crystal display device has been described. However, an optically anisotropic film formed from the liquid crystal composition of the present invention can also be used for optical compensation of liquid crystal display devices of other modes. TN mode liquid crystal cell retardation plates (optical compensation sheets) are described in JP-A-6-214116, US Pat. Nos. 5,583,679, 5,646,703, and German Patent 3,911,620A1. A retardation plate (optical compensation sheet) for liquid crystal cells in IPS mode or FLC mode is described in JP-A-10-54982. Further, a retardation plate (optical compensation sheet) for an OCB mode or HAN mode liquid crystal cell is described in US Pat. No. 5,805,253 and International Publication WO96 / 37804. Furthermore, a retardation plate (optical compensation sheet) for a liquid crystal cell in STN mode is described in JP-A-9-26572. A VA mode liquid crystal cell retardation plate (optical compensation sheet) is described in Japanese Patent No. 2866372. It can be used as an alternative to these optical compensation sheets.
Furthermore, there is an effect of using the optically anisotropic film of the present invention in combination with a polarizing plate for the purpose of preventing reflection of an electroluminescence device or a field emission display device.

5. Heat Resistance of Optical Anisotropic Film The optical anisotropic film formed from the liquid crystal composition of the present invention is also used as an in-cell type optical compensation film formed in a liquid crystal cell as described above. When used as an in-cell type, after forming an optically anisotropic film as described above, a color filter layer, a transparent electrode layer, an alignment layer, and the like are formed. In the process of forming each of these layers, the heating and firing process is repeated. The optically anisotropic film is required to exhibit desired optical properties after undergoing these repeated heating and baking steps. Although it is possible to increase the characteristic value of the optically anisotropic film in advance in anticipation of fluctuations in the heating and baking process (in most cases, the value of in-plane retardation Re decreases) Since various conditions are assumed, it is almost difficult to finally achieve a desired characteristic value. That is, the optically anisotropic film is desirably a highly heat-resistant film that hardly changes in optical characteristics even after the heating and baking process.
The heat resistance is preferably 80% or more, more preferably 90% or more, and more preferably 95% as an in-plane retardation Re retention ratio for a forced condition test (heating at 230 ° C. for 3 hours). The above is particularly preferable. Here, the Re retention rate indicates the ratio of Re (550) after heat treatment to Re (550) before heat treatment.

  The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

(Preparation of coating liquid C-1 for optically anisotropic layer)
After preparing the following composition, it filtered with the polypropylene filter with the hole diameter of 0.2 micrometer, and used as the coating liquid C-1 for optical anisotropic layers.

───────────────────────────────────
Coating liquid composition for optically anisotropic layer (% by mass)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
15.78
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
2.99
Photopolymerization initiator (the above oxadiazole compound compound 1-3) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

W-1: TetrahedronLett. It was synthesized according to the method described in Journal, Vol. 43, page 6793 (2002).

(Preparation of coating liquid C-2 for optically anisotropic layer)
After preparing the following composition, it filtered with the polypropylene filter with the hole diameter of 0.2 micrometer, and used as the coating liquid C-2 for optically anisotropic layers.

───────────────────────────────────
Coating liquid composition for optically anisotropic layer (% by mass)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
14.20
Rod-shaped liquid crystal compound (LC-1) 1.58
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
2.99
Photopolymerization initiator (the above oxadiazole compound 1-3) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

LC-1: Synthesized by condensing 4- (6-acryloyloxyhexyloxy) benzoic acid synthesized by the method described in EP1174411B1 and 4-propylcyclohexylphenol (manufactured by Kanto Chemical).

(Preparation of coating liquid C-3-5 for optically anisotropic layer)
Except for changing the composition ratio of the rod-like liquid crystal compound as described in Table 1 below, the coating liquids C-3 to 5 for the optical anisotropic layer were prepared in the same manner as the coating liquid C-1 for the optical anisotropic layer. Obtained.

(Adjustment of coating liquid C-6 for optically anisotropic layer)
The coating liquid C for optically anisotropic layers was the same as the coating liquid C-1 for optically anisotropic layers except that the compound 1-3 was replaced with the oxadiazole compound 1-5 as a photopolymerization initiator. -6 was obtained.

(Adjustment of coating liquid C-7 for optically anisotropic layer)
The coating liquid C for optically anisotropic layers was the same as the coating liquid C-1 for optically anisotropic layers except that the compound 1-3 was replaced with the oxadiazole compound 1-7 as a photopolymerization initiator. -7 was obtained.

(Adjustment of coating liquid C-R1 for optically anisotropic layer)
Except that Compound Example 1-3 was replaced with IRGACURE651 (manufactured by Ciba Japan) which is a photopolymerization initiator of a benzylmethyl ketal compound as a photopolymerization initiator, it was the same as coating liquid C-1 for optically anisotropic layers. Thus, a coating liquid C-R1 for the optically anisotropic layer was obtained.

(Adjustment of coating liquid C-R2 for optically anisotropic layer)
Except that Compound Example 1-3 was replaced with IRGACURE184 (manufactured by Ciba Japan) which is a photopolymerization initiator of an α-hydroxyalkylphenone compound as a photopolymerization initiator, Similarly, coating liquid C-R2 for optically anisotropic layer was obtained.

(Adjustment of coating liquid C-R3 for optically anisotropic layer)
As in the case of the optically anisotropic layer coating liquid C-1, except that the compound example 1-3 was replaced with the photopolymerization initiator PI-1 of an α-hydroxyalkylphenone compound as a photopolymerization initiator, An isotropic layer coating solution C-R3 was obtained.

After triflating PI-1: 4-propylcyclohexylphenol (manufactured by Kanto Chemical Co., Inc.), a biphenyl compound was obtained by Suzuki coupling reaction with phenylboronic acid. Furthermore, after acylating the 4′-position of biphenyl with isobutyric chloride and aluminum chloride, the carbon at the α-position of the carbonyl was brominated with bromine and then converted into a hydroxyl group with an alkali.

(Preparation of coating liquid C-R4 for optically anisotropic layer)
After preparing the following composition, it filtered with the filter made from a polypropylene with the hole diameter of 0.2 micrometer, and used as coating liquid C-R4 for optical anisotropic layers.

───────────────────────────────────
Coating liquid composition for optically anisotropic layer (% by mass)
───────────────────────────────────
Rod-shaped liquid crystal compound (LC-1) 1.56
Rod-shaped liquid crystal compound (LC-2) 4.00
Chiral agent (CH-1) 12.60
Chiral agent (CH-2) 1.00
Orienting agent (FC171, 3M) 0.04
Photopolymerization initiator (PI-1) 0.40
Chain transfer agent (SH-1) 0.40
Methyl ethyl ketone 30.00
───────────────────────────────────

LC-2: Angew. Makromol. Chem. It was synthesized according to the method described in Journal, Vol. 183, p. 45 (1990).
CH-1: 4- (6-acryloyloxyhexyloxy) benzoic acid synthesized by the method described in EP1174411B1 and 4-hydroxy-4 ′-(2-methylbutyl) synthesized by the method described in WO / 20010140154A1 Biphenyl was condensed and synthesized.
CH-2: Synthesized by the method described in EP1389199A1.
SH-1: Hydroxypropyl acrylate (manufactured by Aldrich) was mesylated, reacted with 4-propylcyclohexylphenol (manufactured by Kanto Kagaku), and then synthesized by adding hydrogen sulfide.

[Example 1]
The coating liquid C-1 for optically anisotropic layer was applied by spin coating to a glass substrate provided with a commercially available polyimide alignment film (SE-150, manufactured by Nissan Chemical Co., Ltd.). Heat drying at 140 ° C. for 2 minutes. Further, it was aged at 65 ° C. for 2 minutes to form an optically anisotropic layer having a uniform liquid crystal phase. Further, immediately after ripening, a microwave emission type ultraviolet irradiation device (Light Hammer 10, 240 W / cm, Fusion UV) equipped with D-bulb having a strong emission spectrum at 350 to 400 nm as a UV light source is applied to the optically anisotropic layer immediately after aging. System (manufactured by Systems) and a wire grid polarizing filter (ProFlux PPL04C, manufactured by Maxtek) at a position 30 mm away from the irradiation surface so that the transmission axis of the polarizing plate is in the fast axis direction of the transparent support. Then, the optically anisotropic layer of Example 1 was produced by irradiation with polarized UV (illuminance: 100 mW / cm ² , irradiation amount: 1000 mJ / cm ² ). The thickness of the optically anisotropic layer was 3.8 μm.

[Examples 2 to 7]
Optical anisotropy of Examples 2 to 7, respectively, in the same manner as in Example 1, except that the coating liquid C-1 for the optically anisotropic layer was replaced with the coating liquids C-2 to 7 for the optically anisotropic layer. A conductive layer was prepared.

[Comparative Examples 1-4]
Optical anisotropy of Comparative Examples 1 to 4, respectively, in the same manner as in Example 1 except that the coating liquid C-1 for the optically anisotropic layer was replaced with the coating liquids C-R1 to R4 for the optically anisotropic layer. A conductive layer was prepared.

(Phase difference measurement)
By a parallel Nicol method using a fiber type spectrometer (KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments)), an in-plane retardation Re (550) at a measurement wavelength λ = 550 nm and a slow axis as a rotation axis ± The retardation when the 40-degree sample was tilted was measured, Rth (550) was calculated, and the Nz value was also determined.
The retardation of the optically anisotropic film was calibrated with the transmittance data of the substrate without the optically anisotropic film measured in advance, so that only the retardation of the optically anisotropic film was obtained. Table 2 shows the measurement results of the phase difference.
The degree of expression of biaxiality of the optically anisotropic film is evaluated from the Nz value and listed in Table 2.
A: Very preferable as a biaxial film. Nz value = 2.0 to 7.0
○: Preferred as a biaxial film. Nz value = 1.5-8.0
Δ: Insufficient as a biaxial film. Nz value = 1.0-10.0
×: Almost no function as a biaxial film. Nz value = outside the above range

(Heat resistance test)
The Re holding ratio before and after performing the heat treatment at 230 ° C. for 3 hours was determined for the formed optically anisotropic film, and the heat resistance was evaluated. The results are listed in Table 2.
A: Excellent heat resistance. Re retention ratio = 90% or more ○: Excellent heat resistance. Re retention ratio = 75% or more Δ: Heat resistance comparable to that of a general retardation film. Re retention ratio = 60% or more x: Heat resistance is inferior. Re retention rate = less than 60%

Examples 1, 6 and 7 show that when an oxadiazole compound is used as a photopolymerization initiator, an optically anisotropic film exhibiting biaxiality and excellent in heat resistance can be obtained.
From Examples 1 to 5, it can be seen that, when the ratio of the bifunctional liquid crystal compound LC242 having two polymerizable groups in the liquid crystal compound is decreased, the developed biaxiality increases. However, it is also confirmed that the Re retention rate indicating heat resistance is lowered. From the viewpoint of heat resistance, it is understood that the ratio of the bifunctional liquid crystal compound in the liquid crystal compound is preferably 75% or more, and more preferably 80% or more.
In Comparative Examples 1 and 2, it can be seen that although the heat resistance is good, the degree of expression of biaxiality is very low.
In Comparative Example 3, the biaxial expression is higher than Comparative Examples 1 and 2, but it is still an insufficient value. Further, as described in the footnotes in the table, since the curing is slightly insufficient under the polarized UV irradiation conditions in this example, the heat resistance is also a low value.
It can be seen that Comparative Example 4 was not even cured under the polarized UV irradiation conditions in this example.

[Example 8]
Example 1 was carried out in the same manner as in Example 1 except that the coating liquid C-1 for optically anisotropic layer was used and a nitrogen purge step was added so that the oxygen concentration when irradiated with polarized UV was 10%. 8 optically anisotropic layers were prepared. The obtained optical anisotropic film was similarly subjected to retardation measurement and heat resistance test. Each result is shown in Table 3.

[Example 9]
Example 1 was carried out in the same manner as in Example 1 except that the coating liquid C-1 for optically anisotropic layer was used and a nitrogen purge step was added so that the oxygen concentration when irradiated with polarized UV was 5%. 9 optically anisotropic layers were prepared. The obtained optical anisotropic film was similarly subjected to retardation measurement and heat resistance test. Each result is shown in Table 3.

[Example 10]
Except for using the optically anisotropic layer coating liquid C-1 and adding a nitrogen purge step so that the oxygen concentration when irradiated with polarized UV was 0.1%, the same as in Example 1, The optically anisotropic layer of Example 10 was produced. The obtained optical anisotropic film was similarly subjected to retardation measurement and heat resistance test. Each result is shown in Table 3.

  From Examples 8 to 10, it can be seen that the heat resistance is improved when the oxygen concentration is lowered from the atmospheric environment. However, it is also confirmed that the developed biaxiality is reduced. From the viewpoint of the biaxiality that is manifested, it is understood that the oxygen concentration when irradiated with polarized UV is preferably 10% or more.

[Examples 11 to 16]
Example 11 to Example 16 were carried out in the same manner as Example 1 except that the following C-8 to C-11 were used instead of C-1 as the coating solution for the optically anisotropic layer. An optically anisotropic layer was produced. For the obtained optically anisotropic film, the phase difference was measured in the same manner. Moreover, the transparency test by visual observation was done. Each result is shown in Table 44.

(Preparation of coating liquid C-8 for optically anisotropic layer)
After preparing the following composition, it filtered with the filter made from a polypropylene with the hole diameter of 0.2 micrometer, and used as the coating liquid C-8 for optically anisotropic layers.
───────────────────────────────────
Composition of coating liquid C-8 for optically anisotropic layer (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
16.91
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
1.54
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

(Preparation of coating liquid C-9 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid C-9 for an optically anisotropic layer.
───────────────────────────────────
Optically anisotropic layer coating liquid C-9 composition (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
16.91
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
1.86
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

(Preparation of coating liquid C-10 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid C-10 for an optically anisotropic layer.
───────────────────────────────────
Optically anisotropic layer coating liquid C-10 composition (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
16.61
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
2.16
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

(Preparation of coating liquid C-11 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as the coating liquid C-11 for an optically anisotropic layer.
───────────────────────────────────
Composition for coating liquid C-11 for optically anisotropic layer (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
16.04
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
2.73
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

(Preparation of coating liquid C-12 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid C-12 for an optically anisotropic layer.
───────────────────────────────────
Composition of coating liquid C-12 for optically anisotropic layer (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
15.26
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
3.51
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

(Preparation of coating liquid C-13 for optically anisotropic layer)
After preparing the following composition, it filtered with the polypropylene filter with the hole diameter of 0.2 micrometer, and used as the coating liquid C-13 for optical anisotropic layers.
───────────────────────────────────
Composition for coating liquid C-13 for optically anisotropic layer (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
15.26
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
4.10
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

[Comparative Examples 5-6]
Optical anisotropy of Comparative Examples 5 to 6 was performed in the same manner as in Example 1 except that the coating liquid C-1 for optically anisotropic layer was replaced with coating liquids C-R5 to R6 for optically anisotropic layer. A conductive layer was prepared.

(Preparation of coating liquid LC-R5 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid LC-R5 for an optically anisotropic layer.
───────────────────────────────────
Composition for coating LC-R5 for optically anisotropic layer (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
17.54
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
1.23
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

(Preparation of coating liquid LC-R6 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid LC-R6 for an optically anisotropic layer.
───────────────────────────────────
Composition for coating LC-R6 for optically anisotropic layer (mass%)
───────────────────────────────────
Bar-shaped liquid crystal compound (Palicolor LC242, manufactured by BASF Japan)
13.80
Chiral agent (Paliocolor LC756, manufactured by BASF Japan)
4.87
Photopolymerization initiator (triazine compound compound 1-5) 1.20
Orienting agent (W-1) 0.01
Ultraviolet absorber (UV-1) 0.02
Methyl ethyl ketone 30.00
───────────────────────────────────

二軸性評価
◎：二軸性フィルムとして非常に好ましい．Ｎｚ値＝２．０〜７．０
○：二軸性フィルムとして好ましい．Ｎｚ値＝１．５〜８．０
△：二軸性フィルムとしては不十分．Ｎｚ値＝１．０〜１０．０
×：二軸性フィルムとしてはほとんど機能しない．Ｎｚ値＝上記範囲外
透明性評価
〇：選択反射による着色および結晶の析出などが観察されず、無色透明な膜を形成し ている。
×：選択反射により着色がみられる、あるいは析出物が観察され不透明である。

Biaxiality evaluation A: Very preferable as a biaxial film. Nz value = 2.0 to 7.0
○: Preferred as a biaxial film. Nz value = 1.5-8.0
Δ: Insufficient as a biaxial film. Nz value = 1.0-10.0
×: Almost no function as a biaxial film. Nz value = Transparency evaluation outside the above range O: Coloring due to selective reflection and precipitation of crystals are not observed, and a colorless transparent film is formed.
X: Coloring is observed by selective reflection, or precipitates are observed and opaque.

  From Comparative Examples 5 to 6, it can be seen that selective reflection occurs and coloring occurs when the cholesteric pitch increases. Further, it is understood that when the amount of the chiral agent added is increased in order to reduce the cholesteric pitch, precipitation occurs and there is a limit to reducing the cholesteric pitch. From the above results, it is understood that the cholesteric pitch is preferably 80 nm or more and 230 nm or less.

(Preparation of liquid crystal cell substrate)
A substrate having a black matrix formed on an alkali-free glass substrate was prepared.
(Color filter composition)
Each RGB pixel composition having the composition shown in Table 5 was prepared.

The composition of the composition in Table 5 is as follows.
────────────────────────────────── ――――――
R pigment dispersion-1 (mass%)
────────────────────────────────── ――――――
C. I. Pigment Red 254 8.0
5- [3-oxo-2- [4- [3,5-bis (3-diethylaminopropylaminocarbonyl) phenyl] aminocarbonyl] phenylazo] -butyroylaminobenzimidazolone 0.8
Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio (weight average molecular weight 37,000) 8.0
Propylene glycol monomethyl ether acetate 83.2
────────────────────────────────── ――――――

────────────────────────────────── ――――――
R pigment dispersion-2 composition (% by mass)
────────────────────────────────── ――――――
C. I. Pigment Red 177 18.0
Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio (weight average molecular weight 37,000) 12.0
Propylene glycol monomethyl ether acetate 70.0
────────────────────────────────── ――――――

────────────────────────────────── ――――――
G pigment dispersion composition (mass%)
────────────────────────────────── ――――――
C. I. Pigment Green 36 18.0
Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio (weight average molecular weight 37,000) 12.0
Cyclohexanone 35.0
Propylene glycol monomethyl ether acetate 35.0
────────────────────────────────── ――――――

────────────────────────────────── ――――――
Binder 1 composition (mass%)
────────────────────────────────── ――――――
Random copolymer of benzyl methacrylate / methacrylic acid = 78/22 molar ratio (weight average molecular weight 40,000) 27.0
Propylene glycol monomethyl ether acetate 73.0
────────────────────────────────── ――――――

───────────────────────────────────
Binder 2 composition (mass%)
───────────────────────────────────
Benzyl methacrylate / methacrylic acid / methyl methacrylate = 38/25
Random copolymer of 37 molar ratio (weight average molecular weight 30,000) 27.0
Propylene glycol monomethyl ether acetate 73.0
───────────────────────────────────

────────────────────────────────── ――――――
Binder 3 composition (mass%)
────────────────────────────────── ――――――
Random copolymer of benzyl methacrylate / methacrylic acid / methyl methacrylate = 36/22/42 molar ratio (weight average molecular weight 30,000) 27.0
Propylene glycol monomethyl ether acetate 73.0
────────────────────────────────── ――――――

───────────────────────────────────
DPHA composition (mass%)
───────────────────────────────────
KAYARAD DPHA (Nippon Kayaku Co., Ltd.) 76.0
Propylene glycol monomethyl ether acetate 24.0
───────────────────────────────────

(Preparation of R-layer forming solution PP-R1)
The R layer forming liquid PP-R1 is first weighed in the amounts of R pigment dispersion 1, R pigment dispersion 2, and propylene glycol monomethyl ether acetate in the amounts shown in Table 5 and mixed at a temperature of 24 ° C. (± 2 ° C.). And then stirred at 150 rpm for 10 minutes, then the amounts of methyl ethyl ketone, binder 2, DPHA solution, 2-trichloromethyl-5- (p-styrylmethyl) -1,3,4-oxadiazole, 2 , 4-Bis (trichloromethyl) -6- [4- (N, N-diethoxycarbonylmethyl) -3-bromophenyl] -s-triazine and phenothiazine were weighed and this was measured at a temperature of 24 ° C. (± 2 ° C.). Add in order and stir at 150 rpm for 10 minutes, then weigh out the amount of ED152 listed in the table above, mix at a temperature of 24 ° C. (± 2 ° C.) and stir at 150 rpm for 20 minutes And, further, weighed amounts of Megafac F-176PF according to Table 5 and stirred 30rpm30 minutes was added at a temperature 24 ℃ (± 2 ℃), was obtained by filtering with a nylon mesh # 200.

(Preparation of G-layer forming solution PP-G1)
The G-layer forming liquid PP-G1 was first weighed in the amounts of G pigment dispersion, CF yellow EX3393, and propylene glycol monomethyl ether acetate listed in Table 5, mixed at a temperature of 24 ° C. (± 2 ° C.) and 150 rpm for 10 minutes. Stirring and then the amounts of methyl ethyl ketone, cyclohexanone, binder 1, DPHA solution, 2-trichloromethyl-5- (p-styrylmethyl) -1,3,4-oxadiazole, 2,4- Bis (trichloromethyl) -6- [4- (N, N-diethoxycarbonylmethyl) -3-bromophenyl] -s-triazine and phenothiazine are weighed out and added in this order at a temperature of 24 ° C. (± 2 ° C.). And stirred at 150 rpm for 30 minutes, and further weighed out the amount of Megafac F-176PF shown in Table 5 to a temperature of 24 ° C. (± 2 ) Was added with stirring 30rpm5 minutes, and filtering the mixture through a nylon mesh # 200.

(Preparation of B-layer forming solution PP-B1)
The B-layer forming solution PP-B1 is first weighed in amounts of CF Blue EX3357, CF Blue EX3383 and propylene glycol monomethyl ether acetate listed in Table 5, mixed at a temperature of 24 ° C. (± 2 ° C.), and stirred at 150 rpm for 10 minutes. Then, the amounts of methyl ethyl ketone, binder 3, DPHA solution, 2-trichloromethyl-5- (p-styrylmethyl) -1,3,4-oxadiazole, and phenothiazine in the amounts shown in Table 5 were weighed and the temperature was 25 At a temperature of 40 ° C. (± 2 ° C.) and stirred at 150 rpm for 30 minutes, and the amount of Megafac F-176PF shown in Table 5 was weighed out and the temperature was 24 It was obtained by adding at 0 ° C. (± 2 ° C.), stirring at 30 rpm for 5 minutes, and filtering through nylon mesh # 200.

(Preparation of optically anisotropic film)
As the optically anisotropic film R-1 for R, the optically anisotropic layer coating liquid C-4 obtained in the above example was surrounded by a black matrix (light-shielding partition) using a piezoelectric head. The droplets were deposited in the recesses where the layer was to be formed, and dried by heating at 140 ° C. for 2 minutes. Further, after aging for 2 minutes at a temperature of 65 ° C., this layer was immediately irradiated with polarized UV (illuminance: 100 mW / cm ² , irradiation amount: 1000 mJ / cm ² ), and then heated and aged at 130 ° C. to a thickness of 3.8 μm. An optically anisotropic film R-1 was formed.
Similarly, the optically anisotropic films G-1 and B-1 for the G layer and the B layer were formed in fine regions where the G layer and the B layer were to be formed, respectively. As the coating liquid for the optically anisotropic layer, the coating liquids C-3 and C-1 for the optically anisotropic layer obtained in the above examples were used, respectively.
In this embodiment, the conveyance speed and the driving frequency are controlled in the portions corresponding to the R, G, and B pixels, and the coating liquid for each optical anisotropic film is formed in the concave portions corresponding to the desired R, G, and B. Struck.

(Preparation of color filter layer)
PP-R1, PP-G1, and PP-B1, which are liquids for forming the R, G, and B layers obtained above, are determined in advance by using a piezo-type head in a recess surrounded by a light-shielding partition. The droplets were ejected at the positions, and R layer, G layer and B layer were formed respectively.
In this embodiment, the conveyance speed and the driving frequency are controlled for the portions corresponding to the R, G, and B pixels, respectively, and the R, G, and B are respectively set in the concave portions corresponding to the desired R, G, and B. And B-layer forming liquids PP-R1, PP-G1 and PP-B1 were ejected.
Thereafter, drying was performed at a temperature of 100 ° C., and heat treatment was further performed at a temperature of 200 ° C. for 1 hour to form a color filter pixel on the optically anisotropic film.

(Formation of transparent electrode)
A transparent electrode film (having a thickness of 2000 mm) was formed on the produced color filter by sputtering of ITO.

(Formation of alignment layer and liquid crystal cell formation)
Further, a polyimide alignment film was provided thereon. Next, glass beads having a particle diameter of 5 μm were sprayed. Further, an epoxy resin sealant containing spacer particles is printed at a position corresponding to the outer frame of the black matrix provided around the pixel group of the color filter, and the color filter substrate and the counter substrate are pressed at a pressure of 10 kg / cm. Pasted together. Next, the bonded glass substrate was heat-treated at a temperature of 150 ° C. for 90 minutes to cure the sealing agent, thereby obtaining a laminate of two glass substrates. This glass substrate laminate was degassed under vacuum, then returned to atmospheric pressure, and liquid crystal was injected into the gap between the two glass substrates to obtain a liquid crystal cell. A polarizing plate HLC2-2518 manufactured by Sanlitz Co., Ltd. was attached to both surfaces of the liquid crystal cell.

(Production of VA-LCD)
As a cold-cathode tube backlight for a color liquid crystal display device, a phosphor obtained by mixing BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn and LaPO ₄ : Ce, Tb at a mass ratio of 50:50 is green (G), Y ₂ O ₃ : Eu was red (R) and BaMgAl ₁₀ O ₁₇ : Eu was blue (B) to produce a white three-wavelength fluorescent lamp having an arbitrary color tone. A liquid crystal cell provided with the above polarizing plate was placed on the backlight to produce a VA-LCD.

(Evaluation of VA-LCD)
In the fabricated VA-LCD, the black display in the azimuth angle of 45 degrees and the polar angle in the direction of 60 degrees and the color shift between the azimuth angle of 45 degrees and the azimuth angle of 180 degrees and the polar angle of 60 degrees were observed. .
As a result of observing the manufactured VA-LCD, it was confirmed that neutral black display was realized in both the front direction and the viewing angle direction.

11 Transparent substrate 12 Black matrix
13 Optical Anisotropy Film 14 Color Filter Layer 21 Transfer Substrate 22 Black Matrix (Partition Wall)
23 Color filter layer 24 Solid optical anisotropic film 25 Transparent electrode layer 26 Alignment layer 27 Patterning optical anisotropic film 31 Liquid crystal 32 TFT
33 Polarizing layer 34 Cellulose acetate film (polarizing plate protective film)
35 Cellulose acetate film or optical compensation sheet 36 Polarizing plate 37 Liquid crystal cell

Claims (13)

A liquid crystal composition comprising a polymerizable liquid crystal compound and a polymerization initiator containing an oxadiazole compound represented by the following general formula (1) for producing a deformed twisted spiral biaxial optically anisotropic film :

In the formula, X ¹ represents a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a cyano group, a monohalomethyl group, a dihalomethyl group, and a trihalomethyl group, and Y ¹ and Y ² are each independently And the following groups:

Represents a divalent linking group selected from: B ¹ and B ² each independently represents an optionally substituted aromatic ring; l, m and n are each independently 0, 1 and 2 Represents any integer selected. 2. The liquid crystal composition according to claim 1, comprising at least one polymerizable liquid crystal compound having two or more polymerizable groups. The liquid crystal composition according to claim 2, wherein a ratio of the polymerizable liquid crystal compound having two or more polymerizable groups to the total mass of the liquid crystal compound is 75% by mass or more. An optically anisotropic film formed by irradiating polarized light to the liquid crystal composition according to claim 1. The optically anisotropic film according to claim 4, wherein the cholesteric pitch of the helical structure is 80 nm or more and 230 nm or less. A color filter substrate comprising a substrate and the optically anisotropic film according to claim 4. A liquid crystal cell substrate comprising a substrate and the optically anisotropic film according to claim 4. A liquid crystal display device comprising the optically anisotropic film according to claim 4. The liquid crystal display device according to claim 8, which is a VA mode liquid crystal display device. The liquid crystal display device according to claim 8, wherein the liquid crystal cell has an optically anisotropic film. The liquid crystal display device according to claim 10, wherein the optically anisotropic film is disposed in each region corresponding to each pixel in the liquid crystal cell. A method for producing a biaxial optically anisotropic film, wherein the liquid crystal composition according to any one of claims 1 to 3 is applied to a support, the liquid crystal composition is cholesterically aligned, and Then, the manufacturing method of the optically anisotropic film | membrane characterized by including the process of irradiating polarized light to this liquid-crystal composition, and not including the process of irradiating non-polarized light before the process of irradiating the said polarized light. The manufacturing method according to claim 12, wherein the oxygen concentration in the step of irradiating polarized light is 10% or more and 21% or less.

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