WO2015053232A1

WO2015053232A1 - Liquid-crystal alignment agent, liquid-crystal alignment film, and liquid-crystal display element

Info

Publication number: WO2015053232A1
Application number: PCT/JP2014/076725
Authority: WO
Inventors: 亮一芦澤; 耕平後藤; 悟志南; 正人森内; 勇太川野
Original assignee: 日産化学工業株式会社
Priority date: 2013-10-07
Filing date: 2014-10-06
Publication date: 2015-04-16
Also published as: KR102351459B1; JPWO2015053232A1; JP6418401B2; TW201529726A; CN105814478A; CN105814478B; TWI659063B; KR20160067156A

Abstract

This liquid-crystal alignment agent contains a polymer, a polymerizable compound, and a solvent. The polymerizable compound has a polymerizable unsaturated bonding group, a functional group that forms a hydrogen bond, and at least one aromatic ring near said functional group. The functional group forms intermolecular hydrogen bonds so as to form a mesogenic structure.

Description

Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

The present invention relates to a liquid crystal alignment agent used when producing a liquid crystal alignment film, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element.

Liquid crystal display elements used for liquid crystal televisions, liquid crystal displays, and the like are usually provided with a liquid crystal alignment film for controlling the alignment state of the liquid crystals.

At present, according to the most widespread industrial method, the liquid crystal alignment film is made of a polyamic acid formed on an electrode substrate and / or a surface of a film made of polyimide obtained by imidizing this with cotton, nylon, polyester. The film is rubbed in one direction with a cloth such as a so-called rubbing process, and the alignment is imparted to the liquid crystal alignment film by the rubbing process.

However, the demand for higher performance, higher definition, and larger size of liquid crystal display elements is increasing, and the surface of the liquid crystal alignment film caused by rubbing treatment, dust generation, the influence of mechanical force and static electricity, Various problems such as non-uniformity in the orientation processing surface have been revealed.

A photo-alignment method is known as one of the techniques that do not perform rubbing treatment (see, for example, Patent Document 1). The photo-alignment method irradiates the liquid crystal alignment film with polarized ultraviolet rays to cause a polymer contained in the liquid crystal alignment film to undergo a photoisomerization reaction, a photodimerization reaction, and the like, thereby imparting an alignment ability to the liquid crystal alignment film. Is. The optical alignment method is applied to liquid crystal display elements of IPS (In-Plane Switching) and FFS (Fringe Field Switching) as demands for higher definition and higher quality of liquid crystal display elements increase. (For example, refer to Patent Document 2). As for the IPS system, in recent years, a technique combined with a PSA system (Polymer Sustained Alignment) using a liquid crystal containing a polymerizable compound has been developed in order to further improve the alignment ability.

On the other hand, the VA (vertical) method is known as another technique that does not perform the rubbing process. The VA method includes an MVA (Multi Vertical Alignment) method in which protrusions for controlling the direction in which the liquid crystal is tilted are formed on the TFT substrate or the color filter substrate, and a direction in which the liquid crystal is tilted by forming an slit in the ITO electrode of the substrate. A PVA (Patterned Vertical Alignment) method and a PSA method to be controlled are known. Among VA systems, the PSA system is a technology that has attracted attention in recent years.

In the PSA method, a polymerizable compound that is polymerized by light or heat is added to a liquid crystal, and after the liquid crystal cell is produced, UV is irradiated in a state where the liquid crystal is tilted while applying an electric field. Thereby, the polymerizable compound is polymerized or crosslinked, and the liquid crystal is aligned in the tilt direction. According to this PSA method, it is possible to operate even in a structure in which a slit is formed in one electrode constituting a liquid crystal cell, and a protrusion such as MVA or a slit such as PVA is not provided in the opposite electrode pattern ( For example, see Patent Document 3).
In addition, it has been reported that the response speed of the liquid crystal display device is increased by adding the polymerizable compound to the liquid crystal alignment film instead of the liquid crystal composition (see, for example, Non-Patent Document 1).

However, the solubility of the polymerizable compound added to the liquid crystal aligning agent is low, and there is a problem in storage stability such that the polymerizable compound is precipitated during storage of the liquid crystal aligning agent.
In addition, if unreacted polymerizable compounds remain as impurities in the liquid crystal display element, seizure or the like is likely to occur, and if the amount of UV irradiation is increased in order to reduce the unreacted polymerizable compounds, the liquid crystals and members caused by the ultraviolet rays are increased. There is also a problem that damage is increased and the reliability of the liquid crystal display element is lowered. For this reason, in order to increase the sensitivity of light, it is necessary to increase the conjugation of the polymerizable compound to increase the absorption to the long wavelength side of ultraviolet light, resulting in a larger mesogenic structure or a ring structure. As a result, the problem that the solubility in the liquid crystal aligning agent is further reduced arises.

JP 2004-163646 A JP 2013-080193 A JP 2004-302061 A

In view of such circumstances, the present invention provides a liquid crystal aligning agent having improved solubility of a polymerizable compound and a highly sensitive alignment fixing ability, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element. For the purpose.

As a result of earnest research, the present inventor has a polymerizable unsaturated bond group, a functional group capable of hydrogen bonding, and at least one aromatic ring in the vicinity of the functional group, and the functional group is hydrogenated between molecules. The present inventors have found that a liquid crystal aligning agent containing a polymerizable compound that forms a mesogen structure by forming a bond is extremely effective for achieving the above object, and has completed the present invention.

The gist of the present invention is as follows.

(1) A polymer, a polymerizable compound, and a solvent, wherein the polymerizable compound includes a polymerizable unsaturated bond group, a hydrogen-bonding functional group, and at least one fragrance in the vicinity of the functional group. A liquid crystal aligning agent comprising a ring, wherein the functional group forms a mesogen structure by forming a hydrogen bond between molecules.

(2) The liquid crystal aligning agent according to (1), wherein the functional group is a carboxyl group.

(3) The liquid crystal aligning agent according to the above (1) or (2), wherein the polymerizable compound is at least one selected from the following formulas [1-1] to [1-4] .

(T is an ether, ester, amide bond, S is an alkylene group having 2 to 11 carbon atoms, R is a hydrogen atom or a methyl group, n = 1 or 2)

(4) The liquid crystal according to any one of (1) to (3), wherein the polymerizable compound is at least one selected from the following formulas [2-1] to [2-6] Alignment agent.

(5) The liquid crystal aligning agent according to any one of the above (1) to (4), wherein the polymer has a group for vertically aligning liquid crystals in a side chain.

(6) The liquid crystal aligning agent according to (5), wherein the polymer further has a photopolymerizable group in a side chain.

(7) The liquid crystal aligning agent according to the above (6), wherein the photopolymerizable group is at least one selected from the following formulas [3-1] to [3-7].

(In the formula, Me represents a methyl group.)

(8) The liquid crystal aligning agent according to any one of the above (1) to (4), wherein the polymer has a photoreactive group.

(9) The liquid crystal aligning agent as described in (8) above, wherein the photoreactive group is at least one selected from the following formulas [4-1] to [4-5].

(10) The above polymer (1) to (9), wherein the polymer contains at least one selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor, polysiloxane or poly (meth) acrylate. The liquid crystal aligning agent in any one of.

(11) A liquid crystal alignment film produced using the liquid crystal aligning agent according to any one of (5) to (7), and obtained through a step of irradiating ultraviolet rays while applying a voltage.

(12) A liquid crystal display device comprising the liquid crystal alignment film according to (11).

(13) A liquid crystal alignment film produced using the liquid crystal aligning agent according to (8) or (9) and obtained through a step of irradiating polarized ultraviolet rays.

(14) A liquid crystal display device comprising the liquid crystal alignment film according to (13).

According to the present invention, by containing a polymerizable compound having a functional group that forms a mesogen structure by hydrogen bonding, the solubility of the polymerizable compound is improved, and a liquid crystal aligning agent having a highly sensitive alignment fixing ability, A liquid crystal alignment film and a liquid crystal display element obtained from the liquid crystal aligning agent are realized.

Hereinafter, the present invention will be described in detail.

<Polymerizable compound>
The liquid crystal aligning agent of this invention contains a polymeric compound. The polymerizable compound has a polymerizable unsaturated bond group, a hydrogen bonding functional group, and at least one aromatic ring in the vicinity of the functional group, and the hydrogen bonding functional group forms a hydrogen bond between molecules. This forms a mesogenic structure.

The polymerizable unsaturated bond group refers to an ethylenically unsaturated double bond group that contributes to photopolymerization or photocrosslinking reaction by stimulation with heat, ultraviolet rays or the like. Specific examples include radical polymerizable groups such as vinyl group, (meth) acryloyl group and isopropenyl group, allyl group, styryl group, and α-methylene-γ-butyllactone group.

In addition, the hydrogen bond according to the present invention is a solvent for a liquid crystal aligning agent because of a bias of electrons caused by a difference in electronegativity between a hydrogen atom in a functional group and an atom having high electronegativity adjacent to the hydrogen atom. A bond in which hydrogen atoms cause attractive interaction with other atoms having a high electronegativity in a liquid crystal alignment film or in a liquid crystal alignment film and are formed through hydrogen atoms between molecules. The functional group capable of hydrogen bonding refers to a group that forms hydrogen bonds between molecules in a liquid crystal alignment film or in a solvent of a liquid crystal alignment agent. Such a functional group capable of hydrogen bonding mainly forms a dimer between molecules in a liquid crystal alignment film or a solvent of a liquid crystal alignment agent. Since such a polymerizable compound has a highly polar group such as a carboxyl group and a hydroxyl group, the solubility is very high as compared with a normal polymerizable compound. For this reason, the solubility of the polymerizable compound in the solvent is improved, and precipitation of the polymerizable compound hardly occurs even when the liquid crystal aligning agent is stored (for example, frozen storage).

Furthermore, the functional group capable of hydrogen bonding forms a mesogenic structure by forming a hydrogen bond between molecules. The mesogenic structure means a rigid structure for exhibiting liquid crystallinity. By forming such a mesogen structure via a hydrogen bond, that is, formation of a rigid structure, the sensitivity of the liquid crystal alignment film to light is increased and the alignment fixing ability of the liquid crystal alignment film is improved.

The functional group capable of hydrogen bonding is not particularly limited, and examples thereof include a carboxyl group, a hydroxyl group, a urea group, an amide group, and an imide group. Among these, a carboxyl group is preferable in view of easy formation of a dimer.

Further, since at least one or more aromatic rings of the polymerizable compound are rigid, the mesogenic structure is formed together with the functional group by being positioned in the vicinity of the functional group to be hydrogen bonded. Since these mesogenic structures have pseudo-huge mesogenic structures, conjugation is widened, and absorption is performed up to the ultraviolet region (for example, up to 365 nm) on the long wavelength side. For this reason, the sensitivity becomes high even for ultraviolet irradiation with a long wavelength, and the alignment can be fixed even with ultraviolet irradiation with weak energy. Examples of the aromatic ring include hydrocarbon aromatic rings such as benzene ring, naphthalene ring and anthracene ring, and heteroaromatic rings such as pyridine ring, pyrazine ring and pyrrole ring. The number of aromatic rings is not particularly limited and is preferably 1 to 4. These aromatic rings may have a substituent.

Examples of the polymerizable compound described above include polymerizable compounds having a carboxyl group and represented by the above formulas [1-1] to [1-4] and the above formulas [2-1] to [2-6]. Is mentioned. Since the difference in electronegativity between the hydrogen atom of the carboxyl group and the oxygen atom adjacent to this hydrogen atom is large, by using these polymerizable compounds, a dimer is formed through a stronger hydrogen bond between molecules. Is formed. Since the molecule of such a polymerizable compound is very small, each molecule of the dimer is also very small. Thereby, the solubility of the polymerizable compound in the solvent is further improved, and the sensitivity of the liquid crystal alignment film to light is further increased. Further, the polymerizable compounds represented by the above formulas [1-1] to [1-4] and the above formulas [2-1] to [2-6] have a mesogenic structure in the vicinity of the carboxyl group together with the carboxyl group. Having two or more aromatic rings. Thereby, the sensitivity with respect to the light of a liquid crystal aligning film becomes still higher, and alignment fixing ability improves more.

Note that the addition ratio of the polymerizable compound added to the liquid crystal aligning agent may be, for example, 0.1 to 30 (mass)% of the polymerizable compound with respect to the liquid crystal aligning agent.

<Liquid crystal aligning agent>
A liquid crystal aligning agent is used in order to produce a liquid crystal aligning film, and contains the said polymeric compound, a polymer, and a solvent. The liquid crystal aligning agent of the present invention is 1) a vertical alignment type produced by irradiating ultraviolet rays while applying a voltage to a liquid crystal cell, that is, a liquid crystal display element of a vertical electric field driving type, or 2) polarized ultraviolet rays ( After passing through the step of irradiating polarized ultraviolet rays, a liquid crystal cell is produced, and the liquid crystal cell is produced by irradiating the ultraviolet rays with an IPS method (In-Plane Switching) or FFS method (Fringe Field Switching). It is used for a liquid crystal display element of a system, that is, a horizontal electric field drive system.

A liquid crystal aligning agent used in a vertical alignment type liquid crystal display element contains a polymer having a side chain having a group for vertically aligning a liquid crystal as a polymer. Further, these polymers may have a photoreactive group or a photoradical generating group in the side chain. When a polymer having such a photoreactive group or photoradical generating group in the side chain is used, photopolymerization or photocrosslinking reaction due to ultraviolet irradiation is more likely to occur, and the alignment and fixing ability is improved.

The liquid crystal aligning agent when used in a horizontal alignment type liquid crystal display element may have a photoreactive group as a polymer. By having a photoreactive group, a photoreaction such as a photoisomerization reaction caused by irradiation with polarized ultraviolet rays occurs, and the liquid crystal alignment film is imparted with a horizontal alignment ability even without a rubbing treatment (so-called photoalignment). Hereinafter, a group for vertically aligning the liquid crystal, a photopolymerizable group, and a photoreactive group will be described.

<Group for aligning liquid crystal vertically>
When the liquid crystal display element is of a vertical alignment type, the polymer contained in the liquid crystal aligning agent has a group for vertically aligning the liquid crystal in the side chain. The group for aligning the liquid crystal vertically is a group having the ability to align liquid crystal molecules vertically with respect to the substrate, and the structure is not particularly limited as long as it has this ability. Examples of the group for vertically aligning the liquid crystal include a linear alkyl group, a linear fluoroalkyl group, a cyclic group having an alkyl group or a fluoroalkyl group at the terminal, and a steroid group. Specific examples include groups represented by the following formula [5].

R ¹ represents an alkylene group having 2 to 6, preferably 2 to 4 carbon atoms, —O—, —COO—, —OCO—, —NHCO—, —CONH—, or an alkylene-ether group having 1 to 3 carbon atoms. (—C—C—O—) is represented. Among these, from the viewpoint of easy synthesis, —O—, —COO—, —CONH—, or an alkylene-ether group having 1 to 3 carbon atoms is preferable. R ² , R ³ and R ⁴ each independently represent a phenylene group or a cycloalkylene group. The combination of a, b, c, R ² , R ³ and R ⁴ shown in Table 1 is preferable from the viewpoint of ease of synthesis and ability to orient the liquid crystal vertically.

R ⁵ represents a hydrogen atom, an alkyl group having 2 to 24 carbon atoms, preferably 5 to 8 carbon atoms or a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic group composed of these. When at least one of a, b and c is 1, the structure of R ⁵ is preferably a hydrogen atom, an alkyl group having 2 to 14 carbon atoms, or a fluorine-containing alkyl group having 2 to 14 carbon atoms, and more It preferably represents a hydrogen atom, an alkyl group having 2 to 12 carbon atoms, preferably 2 to 10 carbon atoms, or a fluorine-containing alkyl group.

When a, b and c are all 0, the structure of R ⁵ is preferably an alkyl group or a fluorine-containing alkyl group having 12 to 22 carbon atoms, preferably 12 to 20 carbon atoms, an aromatic ring, an aliphatic ring, a hetero ring. A ring or a macrocyclic group composed of these, more preferably an alkyl group having 12 to 20 carbon atoms, preferably 12 to 18 carbon atoms, or a fluorine-containing alkyl group.

The side chain of the group that orients the liquid crystal vertically may be directly bonded to the main chain of the polymer, or may be bonded through an appropriate bonding group. Thus, the method for introducing the group for vertically aligning the liquid crystal into the side chain is not particularly limited.

In addition, the amount of the group that vertically aligns the liquid crystal is preferably within a range in which the alignment can be fixed, and other characteristics are not affected in order to further improve the sensitivity to light and the alignment fixing ability. In the range, as much as possible is preferable.

<Photopolymerizable group>
The polymer contained in the liquid crystal aligning agent of the present invention may further have a photopolymerizable group in the side chain. The photopolymerizable group is a group that undergoes a polymerization reaction by light such as ultraviolet rays, for example, a group that is polymerized by light such as ultraviolet rays (hereinafter also referred to as a photopolymerizable group) or a photocrosslinkable group (hereinafter also referred to as a photocrosslinkable group). In particular, at least one selected from the photopolymerizable groups represented by the above formulas [3-1] to [3-7] is preferably used.

A liquid crystal aligning film obtained using a liquid crystal aligning agent containing such a polymer contains a photopolymerizable group. When a liquid crystal display element containing a photopolymerizable group in the liquid crystal alignment film is irradiated with light such as ultraviolet rays, the photopolymerizable group located on the surface where the liquid crystal alignment film and the liquid crystal are in contact with each other, or the polymerizable property of the above-described polymerizable compound The unsaturated bonding group causes photopolymerization or photocrosslinking reaction, and the alignment of the liquid crystal positioned on the surface of the liquid crystal alignment film is more efficiently fixed.

The photopolymerizable group introduced into the side chain of the polymer (hereinafter also referred to as photopolymerizable side chain) is a methacryl group, an acrylic group, a vinyl group, an allyl group, a styryl group, or an α-methylene-γ-butyrolactone group. A side chain containing at least one selected from is preferred.

Such a photopolymerizable side chain may be directly bonded to the main chain of the polymer, or may be bonded through an appropriate bonding group. Thus, the method for introducing the photopolymerizable side chain is not particularly limited. Examples of the photopolymerizable side chain include those represented by the following formula [6].

In the formula [6], R ⁶ represents a single bond or —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N ( CH ₃ ) —, —CON (CH ₃ ) —, —N (CH ₃ ) CO—, wherein R ⁷ is a single bond, unsubstituted or substituted with a fluorine atom, having 1 to 20 represents an alkylene group, and —CH ₂ — in the alkylene group may be optionally replaced by —CF ₂ — or —CH═CH—, and when any of the following groups is not adjacent to each other: These groups may be substituted; —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, a divalent carbocycle, and a divalent heterocycle. R ⁸ represents a methacryl group, an acryl group, a vinyl group, an allyl group, a styryl group, and an α-methylene-γ-butyrolactone group.

R ⁶ in the above formula [6] can be formed by a general organic synthetic method, but from the viewpoint of ease of synthesis, —CH ₂ —, —O—, —COO—, —NHCO —, —NH— and —CH ₂ O— are preferred.

Specific examples of the divalent carbocycle or divalent heterocycle carbocycle or heterocycle for replacing any —CH ₂ — in R ⁷ include the following structures, but are not limited thereto. Is not to be done.

R ⁸ is preferably a methacryl group, an acryl group, a vinyl group or an α-methylene-γ-butyrolactone group from the viewpoint of photopolymerization.

The abundance of the photopolymerizable side chain is preferably within a range where the alignment can be fixed by reacting with irradiation of light such as ultraviolet rays to form a covalent bond, and the sensitivity to light and the alignment fixing ability are further improved. In order to achieve this, as much as possible is preferable as long as other characteristics are not affected.

<Photoreactive group>
In the case of a horizontal alignment method such as an IPS method or an FFS method in which a liquid crystal display element is irradiated with polarized ultraviolet rays, the polymer containing the liquid crystal aligning agent is a photoreaction that exhibits liquid crystal alignment ability by using polarized ultraviolet rays. It is preferable that a sex group is introduced.

By irradiating polarized ultraviolet rays to a liquid crystal alignment film obtained from a liquid crystal aligning agent containing a polymer having a photoreactive group introduced, a photoreaction progresses and is the same as the polarization direction or perpendicular to the polarization direction. Anisotropy is imparted in the direction, and the liquid crystal is aligned. Photoreaction includes photodimerization and photoisomerization. As the photoreactive group, those having an unsaturated bond, particularly a double bond, are preferable, and examples thereof include an acrylic group, a vinyl group, a methacryl group, an anthracenyl group, a calconyl group, a coumarin group, a stilbene group, a maleimide group, and a cinnamoyl group. It is done.

As a specific example, examples of the structure in which the photodimerization reaction proceeds include structures represented by the above formulas [4-1] to [4-3]. Examples of the structure in which the photoisomerization reaction proceeds include structures represented by the above formulas [4-4] and [4-5]. The photoreactive group having a structure selected from the above formulas [4-1] to [4-5] refers to any number of H from the structures of the formulas [4-1] to [4-5]. A group in which O is a bond in the above formula [4-1], or a group in which these structures are bonded to other structures (such as an alkylene group).

Such a photoreactive group may be introduced into the main chain of the polymer or may be introduced into the side chain. Thus, the method for introducing the photoreactive group is not particularly limited. Further, the polymer may have a group that vertically aligns the liquid crystal together with the photoreactive group.

The abundance of the photoreactive group is preferably within a range where the photoreaction can be caused and the orientation can be fixed. In order to further improve the sensitivity to light and the ability to fix the orientation, other properties are affected. As much as possible is preferable as long as it does not come out.

<Polymer>
As the polymer contained in the liquid crystal aligning agent of the present invention, polysiloxane and poly (meth) acrylate are preferably used in addition to a polyimide precursor and a polyimide obtained by imidizing it. Here, the polyimide precursor refers to polyamic acid (also referred to as polyamic acid) or polyamic acid ester. In addition, these different polymers may be simultaneously contained in the liquid crystal aligning agent, and the content ratio thereof is variously selected according to the characteristics of the liquid crystal display element. The total amount of the polymer contained in the liquid crystal aligning agent is preferably 0.1 to 20 (mass)%. The polyimide precursor, polyimide, polymer such as polysiloxane and poly (meth) acrylate contained in the liquid crystal aligning agent of the present invention needs to be soluble in the solvent contained in the liquid crystal aligning agent. Each polymer will be described below.

<Polyimide precursor and polyimide obtained by imidizing it>
When the polymer which the liquid crystal aligning agent of this invention contains a polyimide precursor, a polyimide precursor has a repeating unit (structural unit) represented, for example by following formula [7].

In the formula [7], R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. From the viewpoint of ease of imidization by heating, a hydrogen atom or a methyl group is particularly preferable. X ₂ is a tetravalent organic group, and its structure is not particularly limited. Specific examples include the following formulas [X-1] to [X-43]. From the viewpoint of liquid crystal orientation, X ₂ is preferably [X-1] to [X-10], [X-26] to [X-28], or [X-31] to [X-37].

In the formula [X-1], R ₂ , R ₃ , R ₄ , and R ₅ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms. , An alkenyl group, or a phenyl group. From the viewpoint of liquid crystal orientation, R ₂ , R ₃ , R ₄ and R ₅ are preferably a hydrogen atom, a halogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group, and still more preferably At least one selected from the group consisting of structures represented by [X1-1] to [X1-2].

When the liquid crystal aligning agent of the present invention is used in a liquid crystal display device produced by irradiating polarized ultraviolet rays, preferred structures of X ₂ include [X1-1], [X1-2], [X-2] , [X-3], [X-5], [X-6], [X-7], [X-8], [X-9], [X-10], and [X1-1] ], [X1-2] and [X-6] are particularly preferred.

In the formula [7], Y ₂ is a divalent organic group, the structure thereof is not particularly limited. Specific examples of Y ₂ include the following formulas [Y-1] to [Y-73].

(In the formula, Me represents a methyl group.)

Since improvement in solubility in organic solvents such as polyimide precursor and polyimide can be expected, [Y-8], [Y-20], [Y-21], [Y-22], [Y-28], [Y It is preferable to have a structural unit having a structure of Y-29] or [Y-30].

The polyimide precursor contained in the liquid crystal aligning agent of the present invention has a diamine component (for example, a diamine having a side chain for vertically aligning a liquid crystal described later, a diamine having a photopolymerizable side chain, or a photoreactive group. A diamine such as a diamine) and a tetracarboxylic dianhydride component (for example, tetracarboxylic dianhydride, tetracarboxylic diester dichloride, tetracarboxylic diester, etc. described later). Examples of the polyimide precursor include polyamic acid and polyamic acid ester. Specifically, a polyamic acid is obtained by reaction of a diamine component and tetracarboxylic dianhydride. The polyamic acid ester can be obtained by reacting the diamine component and tetracarboxylic acid diester dichloride in the presence of a base, or reacting the diamine component and tetracarboxylic acid diester in the presence of a suitable condensing agent or base. Polyimide can be obtained by dehydrating and ring-closing this polyamic acid or by heating and ring-closing the polyamic acid ester. Any of such polyamic acid, polyamic acid ester, and polyimide is useful as a polymer for obtaining a liquid crystal alignment film.

<Diamines with side chains that align liquid crystals vertically>
Examples of the diamine having a side chain for vertically aligning the liquid crystal include a long chain alkyl group, a group having a ring structure or a branched structure in the middle of the long chain alkyl group, a hydrocarbon group such as a steroid group, and the hydrogen of these groups. A diamine having a group in which a part or all of the atoms are replaced with fluorine atoms as a side chain, for example, a diamine having a side chain represented by the above formula [5] can be mentioned. More specifically, for example, diamines having a hydrocarbon group having 8 to 30 carbon atoms, in which hydrogen atoms may be substituted with fluorine, and diamines represented by the following formulas [8] to [11] are exemplified. However, the present invention is not limited to this.

(The definitions of a, b, c, and R ¹ to R ⁵ in Formula [8] are the same as in Formula [5] above.)

(In Formula [9] and Formula [10], A ₁₀ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. , A ₁₁ represents a single bond or a phenylene group, a ₁₀ represents the same structure as the side chain for vertically aligning the liquid crystal represented by the above formula [5], and a ₁₀ ′ represents the above formula [5]. (This represents a divalent group having a structure in which one element such as hydrogen is removed from the same structure as the side chain for vertically aligning the liquid crystal.)

(In the formula [11], A ₁₄ is an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and A ₁₅ is a 1,4-cyclohexylene group, or 1,4- A phenylene group, A ₁₆ is an oxygen atom or —COO— * (where a bond marked with “*” is bonded to A ₁₅ ), and A ₁₇ is an oxygen atom or —COO — * ( However, bond marked with "*" is _(CH 2) binds to _{a 2.)} is. in addition, _{a 1} is 0, or an integer 1, _{a 2} is an integer from 2 to 10, a ₃ is 0 or an integer of 1.

The bonding position of the two amino groups (—NH ₂ ) in the formula [8] is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

Specific examples of the structure of the formula [8] include diamines represented by the following formulas [A-1] to [A-24], but are not limited thereto.

(In the formulas [A-1] to [A-5], A ₁ is an alkyl group having 2 to 24 carbon atoms or a fluorine-containing alkyl group.)

(In Formula [A-6] and Formula [A-7], A ₂ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and ₃ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

(In the formulas [A-8] to [A-10], A ₄ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, or —CH ₂ —, and A ₅ represents an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

(In Formula [A-11] and Formula [A-12], A ₆ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ —, —O—, or —NH—, and A ₇ represents fluorine group, cyano group, trifluoromethane group, nitro group, azo group, formyl group, acetyl group, acetoxy Group or hydroxyl group.)

(In Formula [A-13] and Formula [A-14], A ₈ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. .)

(In the formulas [A-15] and [A-16], A ₉ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. .)

Specific examples of the diamine represented by the formula [9] include diamines represented by the following formulas [A-25] to [A-30], but are not limited thereto.

(In the formulas [A-25] to [A-30], A ₁₂ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—, and A ₁₃ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

Specific examples of the diamine represented by the formula [10] include diamines represented by the following formulas [A-31] to [A-32], but are not limited thereto.

Among these, [A-1], [A-2], [A-3], [A-4], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5] The diamines of A-25], [A-26], [A-27], [A-28], [A-29], and [A-30] are preferred.

The above-mentioned diamines can be used alone or in combination of two or more depending on the properties such as liquid crystal orientation, pretilt angle, voltage holding property, and accumulated charge when the liquid crystal alignment film is used.

<Diamine having photopolymerizable side chain>
When the liquid crystal aligning agent of this invention is used for the liquid crystal display element of a vertical alignment system, the photopolymerizable side chain may be introduce | transduced into the diamine component used as the raw material of the polyimide precursor which a liquid crystal aligning agent contains. preferable. The diamine having a photopolymerizable side chain includes at least one selected from a methacryl group, an acryl group, a vinyl group, an allyl group, a styryl group, and an α-methylene-γ-butyrolactone group, and includes, for example, the above formula [6] A diamine having a side chain represented by More specifically, for example, diamines represented by the following general formula [12] can be exemplified, but the invention is not limited thereto.

(The definitions of R ⁶ , R ⁷ and R ⁸ in Formula [12] are the same as in Formula [6] above.)

The bonding position of the two amino groups (—NH ₂ ) in the formula [12] is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

Specific examples of the diamine having a photopolymerizable side chain containing at least one selected from a methacryl group, an acryl group, a vinyl group, an allyl group, a styryl group, and an α-methylene-γ-butyrolactone group are as follows. However, it is not limited to this.

(Wherein R ₆ represents a group selected from —CH ₂ —, —O—, —CONH—, —NHCO—, —COO—, —OCO—, —NH—, —CO—. R ₇ represents An alkylene group having 1 to 30 carbon atoms, a divalent carbocycle or a heterocycle, and one or more hydrogen atoms of the alkylene group, divalent carbocycle or heterocycle are a fluorine atom or . may be replaced by an organic radical addition, R ₇ is in the if any of the following groups not adjacent to each other, -CH 2 _- may be replaced by these groups; -O- , —NHCO—, —CONH—, —COO—, —OCO—, —NH—, —NHCONH—, —CO—, R ₈ represents —CH ₂ —, —O—, —CONH—, —NHCO—, —COO—, —OCO—, —NH—, —CO—, R ₉ represents a single bond, R ₉ represents a cinnamoyl group, R ₁₀ represents a single bond, an alkylene group having 1 to 30 carbon atoms, a divalent carbocyclic ring or a heterocyclic ring, One or more hydrogen atoms of the alkylene group, divalent carbocycle or heterocyclic ring may be replaced with a fluorine atom or an organic group, and R ₁₀ may be any of the following groups adjacent to each other: In this case, —CH ₂ — may be replaced by these groups; —O—, —NHCO—, —CONH—, —COO—, —OCO—, —NH—, —NHCONH—, — CO— R ₁₁ represents a photopolymerizable group selected from an acrylic group and a methacryl group.)

(X is a single bond, or a bonding group selected from —O—, —COO—, —NHCO—, —NH—, Y is a single bond, unsubstituted or substituted with a fluorine atom, Represents 20 alkylene groups.)

The diamine having a photopolymerizable side chain containing at least one selected from the methacryl group, acryl group, vinyl group, allyl group, styryl group and α-methylene-γ-butyrolactone group is a liquid crystal alignment film. Depending on the liquid crystal orientation, sensitivity to light, pretilt angle, voltage holding characteristics, accumulated charge characteristics, liquid crystal display response speed, etc. You can also.

Further, such a diamine having a photopolymerizable side chain containing at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a styryl group, and an α-methylene-γ-butyrolactone group is a polyamic acid. It is preferable to use an amount that is 10 to 70 mol% of the total amount of diamine components used in the synthesis, more preferably 20 to 60 mol%, and particularly preferably 30 to 50 mol%.

<Diamine having photoreactive group>
When the liquid crystal aligning agent of the present invention is used in a liquid crystal display device produced by irradiating polarized ultraviolet rays, a photoreactive group is introduced into the diamine component that is a raw material for the polyimide precursor contained in the liquid crystal aligning agent. It is preferable.

In the case of using an orientation treatment method in which photodimerization reaction or photoisomerization reaction proceeds by irradiation with polarized ultraviolet rays and anisotropy is generated, the structure of the above formulas [4-1] to [4-5] It may be introduced into the main chain or side chain.

When using a polyimide precursor and a polyimide obtained by imidizing it as a polymer to be contained in the liquid crystal aligning agent, the structure of the above formulas [4-1] to [4-5] is contained in the main chain or side chain. Although there is a method using tetracarboxylic dianhydride or diamine, it is preferable to use a diamine containing the structure of the above formulas [4-1] to [4-5] in the side chain from the viewpoint of ease of synthesis. . The side chain of diamine is a structure branched from a structure connecting two amino groups of diamine. Specific examples of such diamines include, but are not limited to, compounds represented by the following formula.

(Wherein X is a single bond or a linking group selected from —O—, —COO—, —NHCO—, —NH—, Y is a single bond, or carbon that is unsubstituted or substituted by a fluorine atom. Represents an alkylene group having a number of 1 to 20. R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms which is unsubstituted or substituted by a fluorine atom, or an alkyl ether group.

<Tetracarboxylic dianhydride>
In order to obtain the polyamic acid which is a polyimide precursor contained in the liquid crystal aligning agent of this invention, the tetracarboxylic dianhydride made to react with a diamine component is not specifically limited. Specific examples are given below.

Examples of the tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic Acid dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 1, , 3,4-Butanetetracarboxylic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetra Carboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride , Tricyclo [4.2.1.0 ^2,5 ] nonane-3,4,7,8-tetracarboxylic acid-3,4: 7,8-dianhydride, hexacyclo [6.6.0.1 ^{2 , 7} . 0 ^3,6 . 1 ^9,14 . 0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid-4,5: 11,12-dianhydride, 4- (2,5-di-oxo-tetrahydrofuran-3-yl) -1,2 3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride and the like.

Furthermore, when an aromatic tetracarboxylic dianhydride is used in addition to the tetracyclic dianhydride having the alicyclic structure or aliphatic structure, the liquid crystal alignment is improved and the accumulated charge of the liquid crystal cell is reduced. Since it can reduce, it is preferable. Aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic acid Dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′, 4-benzophenonetetra Carboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride And 2,3,6,7-naphthalenetetracarboxylic dianhydride and the like.

Tetracarboxylic dianhydride can be used singly or in combination of two or more according to properties such as liquid crystal orientation, sensitivity to light, pretilt angle, voltage holding characteristics, accumulated charge, etc. when a liquid crystal alignment film is formed. .

The tetracarboxylic acid dialkyl ester that is reacted with the diamine component in order to obtain a polyamic acid ester that is a polyimide precursor contained in the liquid crystal aligning agent of the present invention is not particularly limited. Specific examples are given below.

Specific examples of the aliphatic tetracarboxylic acid diester include 1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1 , 3-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2, 3,4-cyclopentanetetracarboxylic acid dialkyl ester, 2,3,4,5-tetrahydrofurantetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl ester, 3,4-dicarboxy-1 -Cyclohexyl succinic acid dialkyl ester, 3,4-dicarboxy- , 2,3,4-Tetrahydro-1-naphthalene succinic acid dialkyl ester, 1,2,3,4-butanetetracarboxylic acid dialkyl ester, bicyclo [3,3,0] octane-2,4,6,8- Tetracarboxylic acid dialkyl ester, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentylacetic acid dialkyl ester, cis-3,7-dibutylcycloocta-1,5- Diene-1,2,5,6-tetracarboxylic acid dialkyl ester, tricyclo [4.2.1.0 ^2,5 ] nonane-3,4,7,8-tetracarboxylic acid-3, 4: 7,8 A dialkyl ester, hexacyclo [6.6. ^{12, 7} . 0 ^3,6 . 1 ^9,14 . 0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid-4,5: 11,12-dialkyl ester, 4- (2,5-di-oxo-tetrahydrofuran-3-yl) -1,2, Examples include 3,4-tetrahydronaphthalene-1,2-dicarboxylic dialkyl ester.

Examples of the aromatic tetracarboxylic acid dialkyl ester include pyromellitic acid dialkyl ester, 3,3 ′, 4,4′-biphenyltetracarboxylic acid dialkyl ester, 2,2 ′, 3,3′-biphenyltetracarboxylic acid dialkyl ester, 2,3,3 ′, 4-biphenyltetracarboxylic acid dialkyl ester, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dialkyl ester, 2,3,3 ′, 4-benzophenone tetracarboxylic acid dialkyl ester, bis (3,4-dicarboxyphenyl) ether dialkyl ester, bis (3,4-dicarboxyphenyl) sulfone dialkyl ester, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl ester, 2,3,6,7- Naphthalenetetracarboxylic acid dialkyl es Le and the like.

<Polysiloxane>
When the polymer contained in the liquid crystal aligning agent contains polysiloxane, the polysiloxane can be obtained by reacting an alkoxysilane component in an organic solvent (for example, polycondensation reaction). The alkoxysilane component refers to an alkoxysilane having 1 to 4 alkoxy groups in the molecule. For example, polysiloxane can be obtained by reacting an alkoxysilane component represented by the following formula [14].

In the formula [14], R ¹¹ represents a monovalent organic group, and R ¹² is alkyl having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms. More preferably, R ¹² is a methyl group or an ethyl group.

<Alkoxysilane having a vertical alignment side chain>
The alkoxysilane having a side chain to align the liquid crystal vertically, Equation [14] in the alkyl group for R ¹¹ is a long chain, groups having a middle ring structure or branched structure of the long-chain alkyl group, such as a steroid group Examples include hydrocarbon silanes and alkoxysilanes having groups in which some or all of the hydrogen atoms in these groups are replaced by fluorine atoms as side chains, such as diamines having side chains represented by the above formula [5]. it can. More specifically, for example, a diamine having a hydrocarbon group having 8 to 30 carbon atoms in which a hydrogen atom may be substituted with fluorine, or an alkoxysilane represented by the following formula [15] can be given. However, the present invention is not limited to this.

(The definitions of a, b, c, and R ¹ to R ⁵ in Formula [15] are the same as those in Formula [5]. In Formula [15], R ⁹ is a single bond or — (CH ₂ ) _n. O— (n is an alkyl group having 0 to 5 carbon atoms), R ¹² represents an alkyl having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms.)

Here, specific examples of the alkoxysilane having a vertical alignment side chain structure represented by the formula [14] include the formulas [14-1] to [14-13], but are not limited thereto. is not. Incidentally, ^{R 12} in the formula [14-1] - [14-13] is the same as ^{R 12} in the formula [14], R ⁹ is the same as R ⁹ in the formula [15].

(In the formulas [14-7] to [14-9], R ¹³ represents an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.)

(In the formulas [14-10] and [14-11], R ¹⁴ represents a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group.)

(In the formulas [14-12] and [14-13], R ¹⁵ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. )

The alkoxysilane represented by the formula [14] is soluble in a solvent when used as a siloxane polymer (polysiloxane), liquid crystal alignment when used as a liquid crystal alignment film, sensitivity to light, pretilt angle, voltage holding characteristics, One type or a mixture of two or more types can also be used depending on characteristics such as accumulated charge and the response speed of liquid crystal when a liquid crystal display element is used. Further, it can be used in combination with an alkoxysilane containing a long-chain alkyl group having 10 to 18 carbon atoms.

Thus, the alkoxysilane represented by the formula [14] can be produced by a known method as described in, for example, JP-A-61-286393.

<Alkoxysilane having a photopolymerizable side chain>
Moreover, as an alkoxysilane component used for obtaining polysiloxane, for example, an alkoxysilane having a photopolymerizable group represented by the following formula [16] can also be used.

In the formula [16], R ²¹ is an alkyl group in which a hydrogen atom is substituted with an acryl group, an acryloxy group, a methacryl group, a methacryloxy group, or a styryl group. The number of substituted hydrogen atoms is one or more, preferably one. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms. More preferably, it is 1-10. R ²² is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and particularly preferably 1 to 2 carbon atoms.

Although the specific example of the alkoxysilane represented by Formula [16] is given, it is not limited to these. For example, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxymethyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxy Silane, acryloxyethyltrimethoxysilane, acryloxyethyltriethoxysilane, styrylethyltrimethoxysilane, styrylethyltriethoxysilane, and 3- (N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane.

<Other alkoxysilanes>
Furthermore, as an alkoxysilane component used for obtaining polysiloxane, for example, an alkoxysilane represented by the following formula [17] can also be used.

R ²³ of the alkoxysilane represented by the formula [17] may be a hydrogen atom, or the hydrogen atom may be substituted with a hetero atom, a halogen atom, an amino group, a glycidoxy group, a mercapto group, an isocyanate group, or a ureido group. A hydrocarbon group having 1 to 10 carbon atoms, preferably an amino group, a glycid group, or a ureido group. R ²⁴ represents an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and n2 represents an integer of 0 to 3, preferably 0 to 2.

Specific examples of the alkoxysilane represented by the formula [17] are listed below, but are not limited thereto. For example, 3- (2-aminoethylaminopropyl) trimethoxysilane, 3- (2-aminoethylaminopropyl) triethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, 2- (2-aminoethylthioethyl) Triethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, vinyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, chloropropyltriethoxysilane, bromopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, diphenyl Diethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane and γ-ureidopropyltri And propoxysilane.

In the alkoxysilane represented by the formula [17], the alkoxysilane in which n2 is 0 is tetraalkoxysilane. Tetraalkoxysilane is preferable for obtaining a polysiloxane because it easily undergoes a polycondensation reaction with the alkoxysilane represented by the above formulas [14] to [16].

As such an alkoxysilane having n2 of 0 in the formula [17], tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane or tetrabutoxysilane is more preferable, and tetramethoxysilane or tetraethoxysilane is particularly preferable.

The method for obtaining the polysiloxane contained in the liquid crystal aligning agent is not particularly limited. For example, the alkoxysilane component containing the alkoxysilane represented by the above formulas [14] to [17] is reacted in an organic solvent (for example, (Polycondensation reaction). Usually, polysiloxane is obtained as a solution in which such an alkoxysilane component is polycondensed and uniformly dissolved in an organic solvent. The mixing ratio of the alkoxysilane in the alkoxysilane component containing the alkoxysilane such as the above formulas [14] to [17] is not particularly limited.

Examples of the method of polycondensing alkoxysilane to obtain polysiloxane include a method of hydrolyzing and condensing alkoxysilane in an organic solvent such as alcohol or glycol. At that time, the hydrolysis / condensation reaction may be either partial hydrolysis or complete hydrolysis.

When the liquid crystal aligning agent is used in a vertical alignment type liquid crystal display element, the polysiloxane described above has a group for vertically aligning liquid crystals in the side chain and further has a photopolymerizable group in the side chain. May be. Moreover, when a liquid crystal aligning agent is used for the liquid crystal display element of a horizontal alignment system, you may have a photoreactive group. For this reason, it is preferable that the alkoxysilane component which is a monomer has a group or photopolymerizable group for vertically aligning the liquid crystal introduced in the side chain and a photoreactive group introduced in the main chain or side chain. Such a polysiloxane having a group for vertically aligning a liquid crystal, a photopolymerizable group or a photoreactive group is useful as a polymer for obtaining a liquid crystal alignment film exhibiting the ability to fix the alignment of liquid crystals.

<Poly (meth) acrylate>
When the polymer contained in the liquid crystal aligning agent contains poly (meth) acrylate, the poly (meth) acrylate is caused to undergo a polymerization reaction between a monomer such as an acrylic ester compound or a methacrylic ester compound and a polymerization initiator. Is obtained.

Examples of the acrylic ester compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butyl. Acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2- Propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate Such as beauty 8-ethyl-8-tricyclodecyl acrylate.

Examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl. Methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2- Propyl-2-adamantyl methacrylate, 8-me Le -8- tricyclodecylacrylate methacrylate and 8-ethyl-8-tricyclodecyl methacrylate, and the like.

When the liquid crystal aligning agent is used in a vertical alignment type liquid crystal display element, the poly (meth) acrylate described above has a group for vertically aligning liquid crystals in the side chain, and further has a photopolymerizable group in the side chain. You may have. Moreover, when a liquid crystal aligning agent is used for the liquid crystal display element of a horizontal alignment system, you may have a photoreactive group. For this reason, acrylic acid ester compounds and methacrylic acid ester compounds, which are monomers, have a group or photopolymerizable group for vertically aligning liquid crystals introduced into the side chain and a photoreactive group introduced into the main chain or side chain. It is preferable. Such a poly (meth) acrylate having a group for vertically aligning a liquid crystal, a photopolymerizable group or a photoreactive group is useful as a polymer for obtaining a liquid crystal alignment film exhibiting the ability to fix the alignment of liquid crystals. is there.

Here, examples of the acrylate compound having a side chain and the methacrylic acid ester compound include an acrylate compound having a side chain represented by the above formula [5] and a methacrylic acid ester compound. . More specifically, examples include acrylic ester compounds and methacrylic ester compounds represented by the following formula [18] and the following formulas [19-1] to [19-3], but are not limited thereto. Is not to be done.

(Definition of a, b, c and R ¹ to R ^{5 in} the formula [18] is the same as in the above formula [5]. R is a hydrogen atom or a methyl group, and S is an alkylene having 2 to 11 carbon atoms. Group.)

(R is a hydrogen atom or a methyl group, S is an alkylene group having 2 to 11 carbon atoms, X is an ether, ester or amide bond, R ¹⁰ is a hydrogen atom, or an unsubstituted or substituted carbon atom having 1 carbon atom. ˜5 alkyl groups.)

<Solvent>
The solvent which the liquid crystal aligning agent of this invention contains will not be specifically limited if the said polymer and the said polymeric compound which a liquid crystal aligning agent contain melt | dissolve uniformly. Specific examples thereof include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, when a polyimide precursor or polyimide is used as the polymer. N-ethyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, 3-methoxy-N , N-dimethylpropanamide and the like. Further, when polysiloxane is used as the polymer, examples thereof include polyhydric alcohol compounds such as ethylene glycol and 1,2-propylene glycol, amide compounds such as N-methylformamide and N, N-dimethylformamide, and the like. Can do. Moreover, when using poly (meth) acrylate as a polymer, an alcohol compound, a ketone compound, an amide compound, an ester compound, or another aprotic compound can be mentioned, for example. You may use these 1 type or in mixture of 2 or more types. Moreover, even if it is a solvent which cannot melt | dissolve a polymer and a polymeric compound uniformly by itself, as long as a polymer and a polymeric compound do not precipitate, you may mix with said organic solvent.

The liquid crystal aligning agent of this invention may contain the solvent for improving the coating-film uniformity at the time of apply | coating a liquid crystal aligning agent to a board | substrate other than the solvent for dissolving a polymer and a polymeric compound. . As such a solvent, a solvent having a surface tension lower than that of the organic solvent is generally used. Specific examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2 -Propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, butyl cellosolve acetate, di Propylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactic acid Isoamyl ester, and the like. Two or more of these solvents may be used in combination.

In the liquid crystal aligning agent of the present invention, in addition to the above, as long as the effects of the present invention are not impaired, polymers other than the above-mentioned polymers, and the electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film are changed. Target dielectric material or conductive material, silane coupling agent for improving adhesion between liquid crystal alignment film and substrate, compound for improving film thickness uniformity and surface smoothness when liquid crystal alignment agent is applied, liquid crystal Addition of a crosslinkable compound for the purpose of increasing the hardness and density of the film when it is made into an alignment film, and an imidization accelerator for the purpose of efficiently progressing imidation of the polyimide precursor when the coating film is baked. May be.

Examples of compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.) and the like. When these surfactants are used, the ratio of use thereof is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the total amount of polymers contained in the liquid crystal aligning agent. 1 part by mass.

Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds and epoxy group-containing compounds. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether , Polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetra Glycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N′-tetraglycidyl-4, 4′-diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, etc. . In order to further increase the film strength of the liquid crystal alignment film, a phenol compound such as 2,2′-bis (4-hydroxy-3,5-dihydroxymethylphenyl) propane or tetra (methoxymethyl) bisphenol may be added. When these compounds are used, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent.

<Liquid crystal alignment film>
The liquid crystal alignment film used for the liquid crystal display element of the present invention is obtained by applying the liquid crystal aligning agent to a substrate, drying it as necessary, and then performing an alignment treatment on the coating surface obtained by baking. .

The substrate on which the liquid crystal aligning agent is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, and the like can be used. Use of a substrate on which an ITO (Indium Tin Oxide) electrode or the like is formed is preferable from the viewpoint of simplification of the process. In the reflective liquid crystal display element, an opaque object such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light, such as aluminum, can be used.

The application method of the liquid crystal aligning agent is not particularly limited, but industrially, a method performed by screen printing, offset printing, touch basic printing, an inkjet method, or the like is common. Other coating methods include a dipping method, a roll coater method, a slit coater method, a spinner method, and a spray method, and these may be used depending on the purpose.

After the liquid crystal aligning agent is applied on the substrate, the heating means such as a hot plate, a thermal circulation oven or an IR (infrared) oven is used, depending on the solvent used for the liquid crystal aligning agent, 30 to 300 ° C., preferably 30 The liquid crystal alignment film can be obtained by evaporating the solvent at a temperature of ˜250 ° C. If the thickness of the liquid crystal alignment film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. Is 10 to 100 nm.

<Vertical alignment type liquid crystal display element>
The liquid crystal display element of the vertical alignment system of the present invention can be obtained by preparing a liquid crystal cell by a known method after obtaining a substrate with a liquid crystal alignment film containing a polymerizable compound. Specifically, a liquid crystal alignment film is formed by applying and baking a liquid crystal alignment agent on two substrates, and the two substrates are arranged so that the liquid crystal alignment films face each other. A liquid crystal composition containing liquid crystal is injected between the substrates to form a liquid crystal layer. A vertical alignment type liquid crystal display element having a liquid crystal cell is obtained by irradiating ultraviolet rays while applying a voltage to the liquid crystal layer and the liquid crystal alignment film. The liquid crystal composition may contain a polymerizable compound.

In the step of irradiating ultraviolet rays while applying a voltage, the polymerizable unsaturated bond group of the polymerizable compound undergoes photopolymerization or photocrosslinking reaction, and the molecular alignment state of the liquid crystal layer is controlled. Thereby, the alignment of the liquid crystal positioned on the surface of the liquid crystal alignment film is fixed while being slightly inclined from the vertical direction without performing the rubbing treatment.

<Horizontal alignment type liquid crystal display element>
A horizontal alignment liquid crystal display element is a liquid crystal display element that switches liquid crystal molecules by applying an electric field in a horizontal direction (lateral direction) with respect to a substrate. The liquid crystal display element of a horizontal alignment method such as the IPS method or the FFS method of the present invention can be obtained by preparing a liquid crystal cell by a known method after obtaining a substrate with a liquid crystal alignment film containing a polymer compound. . Specifically, the liquid crystal aligning agent is applied onto two substrates and baked, and a rubbing treatment is performed as necessary, and then a liquid crystal alignment film is formed by irradiating polarized ultraviolet rays. Next, two substrates are arranged so that the liquid crystal alignment films face each other, and a liquid crystal composition containing liquid crystal is injected between the two substrates to form a liquid crystal layer. Then, the liquid crystal layer and the liquid crystal alignment film are irradiated with polarized ultraviolet rays to obtain a horizontal alignment type liquid crystal display device having a liquid crystal cell. The liquid crystal composition may contain a polymerizable compound.

The process of irradiating the liquid crystal layer and the liquid crystal alignment film with ultraviolet rays, that is, the step of irradiating ultraviolet rays from the outside of the device after the device is fabricated, causes the polymerizable unsaturated bond group of the polymerizable compound to undergo a photoreaction such as photopolymerization or photocrosslinking. Wake up. Thereby, the liquid crystal located on the surface of the liquid crystal alignment film is fixed while being aligned in the horizontal direction.

The liquid crystal display element of the vertical alignment method or horizontal alignment method of the present invention described above includes a liquid crystal alignment film obtained from a liquid crystal aligning agent containing a polymerizable compound. Since the polymerizable compound in the liquid crystal aligning agent has a functional group capable of hydrogen bonding as described above, it forms a dimer in the liquid crystal alignment film or in the liquid crystal aligning agent through hydrogen bonding. Furthermore, since the polymerizable compound used in the present invention has a rigid aromatic ring, the functional group capable of hydrogen bonding forms a mesogenic structure via the hydrogen bond. This mesogenic structure becomes a pseudo-large mesogenic structure due to hydrogen bonding, and has absorption on the long wavelength side in the ultraviolet region, so that sensitivity to light is improved. Accordingly, a liquid crystal display device having such a liquid crystal alignment film has improved sensitivity to light, a sufficiently high response speed even with ultraviolet light on the long wavelength side, and an alignment fixing ability as shown in the examples described later. It will be excellent.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

The abbreviations used in the preparation of the following liquid crystal aligning agents are as follows.
<Preparation of liquid crystal aligning agent>
BODA: Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride DBA: 3.5-diamino Benzoic acid m-PCH7: 1,3-diamino-5-((4- (4-heptylcyclohexyl) phenoxy) methyl) benzene represented by the following formula

PCH7: 1,3-diamino-4- [4- (4-heptylcyclohexyl) phenoxy] benzene represented by the following formula

BEM-S: 2- (methacryloyloxy) ethyl 3,5-diaminobenzoate represented by the following formula

NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve

<Additives>
3AMP: 3-picolylamine

<Polymerizable compound>
The polymerizable compounds [RM1] to [RM7] added to the liquid crystal aligning agent have the following structure. The polymerizable compounds [RM1] to [RM6] are the same as the polymerizable compounds of the above formulas [2-1] to [2-6].

<Synthesis Example 1>
Synthesis of polymerizable compound [RM1]

In a 3 L four-necked flask, 4-bromo-4′-hydroxybiphenyl [A] (150 g, 0.60 mol), tert-butyl acrylate [B] (162 g, 1.3 mol), palladium acetate (2.7 g, 12 mmol), tri (o-tolyl) phosphine (7.3 g, 24 mmol), tributylamine (334 g, 1.8 mol), N, N-dimethylacetamide (hereinafter abbreviated as DMAc) (750 g) at 100 ° C. Heating and stirring were performed. The reaction was traced by HPLC, and after confirming the completion of the reaction, the reaction solution was cooled to near room temperature, and 1.8 L of 1M hydrochloric acid aqueous solution was poured. Ethyl acetate (1 L) was added thereto, and the aqueous layer was removed by a liquid separation operation. The organic layer was washed twice with 1 L of a 10% aqueous hydrochloric acid solution and three times with 1 L of saturated brine, and then dried over magnesium sulfate. Thereafter, filtration and evaporation of the solvent with an evaporator gave 174 g of Compound [C] as an oily compound (yield 98%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [C] was as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 9.68 (1H, s), 7.72 (2H, d), 7.63 (2H, d), 7.59-7.55 (9H M), 6.87-6.85 (2H, m), 1.44 (9H, s).

In a 2 L four-necked flask equipped with a mechanical stirrer and a stirring blade, the compound [C] obtained above (174 g, 0.59 mol), 6-chloro-1-hexanol (96.7 g, 0.71 mol), potassium carbonate ( 163 g, 1.2 mol), potassium iodide (9.8 g, 59 mmol), N, N-dimethylformamide (hereinafter abbreviated as DMF) (1600 g) were added, and the mixture was heated and stirred at 80 ° C. The reaction was traced by HPLC, and after confirming the completion of the reaction, the reaction solution was cooled to near room temperature, and 2 L of distilled water was poured into the reaction solution. The precipitated solid was filtered off, poured into a methanol / distilled water (1: 1) solution, and filtered again. The obtained solid was dried under reduced pressure to obtain 221 g of compound [D] (yield 95%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [D] was as follows.
¹ H-NMR (400 MHz, CDCl ₃ , δ ppm): 7.61 (1H, d), 7.56-7.52 (6H, m), 6.98-6.95 (2H, m), 6. 38 (1H, d), 4.02 (2H, t), 3.67 (2H, t), 1.84-1.44 (17H, m).

The compound [D] obtained above (221 g, 0.56 mol), triethylamine (67.7 g, 0.67 mol), tetrahydrofuran (hereinafter abbreviated as THF) (1800 g) was added to a 3 L four-necked flask, and the reaction solution was added. Cooled down. A solution of methacrylic acid chloride (70.0 g, 0.67 mmol) in THF (200 g) was added dropwise thereto with care so that the internal temperature did not exceed 10 ° C. After completion of the dropwise addition, the reaction solution was brought to 23 ° C. for further reaction. Reaction tracking was performed by HPLC, and after confirming the completion of the reaction, 6 L of distilled water was poured into the reaction solution, 2 L of ethyl acetate was added, and the aqueous layer was removed by a liquid separation operation. Thereafter, the organic layer was washed successively with 5% aqueous potassium hydroxide solution, 1M aqueous hydrochloric acid solution and saturated brine, and the organic layer was dried over magnesium sulfate. Thereafter, filtration and evaporation of the solvent with an evaporator gave a crude product. The obtained crude product was washed with 100 g of 2-propanol (hereinafter abbreviated as IPA), filtered and dried to obtain 127 g of Compound [E] (yield 49%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [E] was as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 7.73 (2H, d), 7.70-7.63 (4H, m), 7.58 (1H, d), 7.02-7 .00 (2H, m), 6.53 (1H, d), 6.03-6.02 (1H, m), 5.67-5.66 (1H, m), 4.11 (2H, t ), 4.00 (2H, t), 1.88-1.87 (3H, m), 1.79-1.25 (17H, m).

The compound [E] obtained above (81 g, 0.17 mol) and formic acid (400 g) were added to a 1 L four-necked flask, and the mixture was heated and stirred at 40 ° C. The reaction was traced by HPLC, and after confirming the completion of the reaction, 3 L of distilled water was poured into the reaction solution and filtered. The obtained solid was washed with 200 g of methanol and dried to obtain 56 g of a polymerizable compound [RM1] (yield 79%).

The measurement result of the nuclear magnetic resonance (NMR) of the polymerizable compound [RM1] was as follows.
¹ H-NMR (400 MHz, CDCl ₃ , δ ppm): 7.81 (1H, d), 7.60 (4H, s), 7.55 (2H, d), 6.97 (2H, d), 6 .47 (2H, d), 6.11-6.10 (1H, m), 5.56-5.52 (1H, m), 4.17 (2H, t), 4.00 (2H, t ), 1.95-1.94 (2H, m), 1.85-1.82 (3H, m), 1.75-1.71 (2H, m), 1.55-1.48 (4H) , M).

<Synthesis Example 2>
Synthesis of polymerizable compound [RM2]

The same procedure as in Example 1 was performed except that 6-chloro-1-hexanol used in the synthesis of compound [D], which was an intermediate of polymerizable compound [RM1], was changed to 8-chloro-1-hexanol. And 40.82 g of polymerizable compound [RM2] was obtained.

The measurement result of the nuclear magnetic resonance (NMR) of the polymerizable compound [RM2] was as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 7.70-7.56 (7H, m), 6.97 (2H, d), 6.51 (1H, d), 5.98 (1H , S), 5.62 (1H, s), 4.04 (2H, t), 3.94 (2H, t), 1.83 (3H, s), 1.70-1.10 (12H) .

<Synthesis Example 3>
Synthesis of polymerizable compound [RM3]

In a 2 L four-necked flask, 6-bromo-2-naphthol [H] (150 g, 672 mol), tert-butyl acrylate [B] (103.4 g, 807 mmol), palladium acetate (3.02 g, 13.5 mmol) , Tri (o-tolyl) phosphine (8.19 g, 26.9 mmol), tripropylamine (289.0 g, 2.02 mol), and DMAc (700 g) were added, and the mixture was heated and stirred at 100 ° C. The reaction was traced by HPLC, and after confirming the completion of the reaction, the reaction solution was cooled to around room temperature and poured into 3 L of 1M aqueous hydrochloric acid. Ethyl acetate (2 L) was added thereto, and the aqueous layer was removed by a liquid separation operation. The organic layer was washed twice with 1 L of a 10% aqueous hydrochloric acid solution and three times with 1 L of saturated brine, and then dried over magnesium sulfate. Then, 181g of compound [I] was obtained by filtering and distilling a solvent off by the evaporator (yield 99%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [I] was as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 10.1 (1H, s), 8.04 (1H, s), 7.81-7.74 (2H, m), 7.70-7 63 (2H, m), 7.14-7.10 (2H, m), 6.54 (1H, d), 1.51-1.48 (9H, m).
In a 2 L four-necked flask equipped with a mechanical stirrer and a stirring blade, the compound [I] obtained above (181 g, 672 mmol), 6-chloro-1-hexanol (110.2 g, 806 mol), potassium carbonate (111.5 g, 806 mmol), potassium iodide (1.12 g, 6.7 mmol), and DMF (900 g) were added, and the mixture was heated and stirred at 80 ° C. Reaction tracking was performed by HPLC, and after confirming the completion of the reaction, 2 L of distilled water was poured into the reaction solution, ethyl acetate (2 L) was added, and the aqueous layer was removed by a liquid separation operation. Thereafter, the organic layer was washed twice with saturated brine (1 L), the organic layer was dried over magnesium sulfate, filtered, and then the solvent was distilled off to obtain a crude product. The obtained crude product was recrystallized with a mixed solvent of ethyl acetate / hexane to obtain 185 g of Compound [J] (yield 74%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [J] was as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 8.06 (1H, s), 7.80 (1H, d), 7.77-7.76 (2H, m), 7.62 (1H , D), 7.34 (1H, d), 7.15 (1H, dd), 6.53 (1H, d), 4.34 (1H, t), 4.05 (2H, t), 3 39-3.33 (2H, m), 1.73 (2H, t), 1.46-1.31 (15H, m).

The compound [J] obtained above (130.5 g, 352 mmol), triethylamine (42.76 g, 423 mmol), and THF (950 g) were added to a 3 L four-necked flask, and the reaction solution was cooled. A solution of methacrylic acid chloride (44.2 g, 423 mmol) in THF (100 g) was added dropwise thereto with care so that the internal temperature did not exceed 10 ° C. After completion of the dropwise addition, the reaction solution was brought to 23 ° C. for further reaction. Reaction tracking was performed by HPLC, and after confirming the completion of the reaction, 6 L of distilled water was poured into the reaction solution, 2 L of ethyl acetate was added, and the aqueous layer was removed by a liquid separation operation. Thereafter, the organic layer was washed successively with 5% aqueous potassium hydroxide solution, 1M aqueous hydrochloric acid solution and saturated brine, and the organic layer was dried over magnesium sulfate. Thereafter, filtration and evaporation of the solvent with an evaporator gave 140.9 g of Compound [K] (yield 92%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [K] was as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 8.09 (1H, s), 7.83 (1H, d), 7.80-7.79 (2H, m), 7.66 (1H , d), 7.33 (1H, d), 7.18 (1H, dd), 6.57 (1H, d), 6.02-6.01 (1H, m), 5.66-5. 65 (1H, m), 4.12-4.06 (4H, m), 1.88-1.87 (3H, m), 1.84-1.42 (15H, m).

The compound [K] obtained above (140.9 g, 321 mmol) and formic acid (700 g) were added to a 3 L four-necked flask, and the mixture was heated and stirred at 40 ° C. Reaction tracking was performed by HPLC, and after confirming the completion of the reaction, 4.5 L of distilled water was poured into the reaction solution and filtered. The obtained solid was washed with an IPA / hexane mixed solvent, and the solid was dried to obtain 95.9 g of a polymerizable compound [RM3] (yield 78%).

The measurement result of the nuclear magnetic resonance (NMR) of the polymerizable compound [RM3] was as follows.
^{1 H-NMR (400MHz, DMSO} -d6, δppm): 12.4 (1H, brs), 8.10 (1H, s), 7.84 (1H, d), 7.81-7.80 (2H M), 7.70 (1H, d), 7.35 (1H, d), 7.19 (1H, dd), 6.59 (1H, d), 6.03-6.02 (1H, m), 5.67-5.65 (1H, m), 4.13-4.07 (4H, m), 1.88-1.87 (3H, m), 1.83-1.41 ( 8H, m).

<Synthesis Example 4>
Synthesis of polymerizable compound [RM4]

The same procedure as in Example 1 was performed except that 6-chloro-1-hexanol used in the synthesis of compound [J], which was an intermediate of polymerizable compound [RM3], was changed to 8-chloro-1-hexanol. And 171 g of multi-layer compound [RM4] was obtained.

The measurement results of the nuclear magnetic resonance (NMR) of the polymerizable compound [RM4] were as follows.
¹ H-NMR (400 MHz, CDCl 3, δ ppm): 12.4 (1H, brs), 7.94-7.88 (2H, m), 7.77-7.71 (2H, m), 7.70 -7.63 (1H, m), 7.17 (1H, dd), 7.12-7.11 (1H, m), 6.51 (1H, d), 6.11-6.10 (1H M), 5.55-5.54 (1H, m), 4.17-4.06 (4H, m), 1.95-1.94 (3Hm), 1.87-1.40 (12H , M).

<Synthesis Example 5>
A known polymerizable compound represented by the following formula was designated as a polymerizable compound [RM5].

<Synthesis Example 6>
Synthesis of polymerizable compound [RM6]

To a 2 L four-necked flask, add 6-hydroxy-2-naphthalenecarboxylic acid [N] (300 g, 1.59 mol), potassium hydroxide (205 g, 3.66 mol), and distilled water (1200 g), and heat at 100 ° C. Stirring was performed. 6-Chloro-1-hexanol (261 g, 1.91 mol) was added dropwise thereto. After completion of the dropwise addition, the reaction was monitored by HPLC. After confirming the completion of the reaction, the reaction solution was cooled to near room temperature, poured into ice water (3 L), and neutralized by adding 35% hydrochloric acid. Thereafter, the precipitated solid was filtered and washed with distilled water, and then the solid was dried under reduced pressure to obtain 275 g of Compound [O] (yield 60%).

The measurement results of nuclear magnetic resonance (NMR) of the compound [O] were as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 8.53-8.52 (1H, m), 8.06-7.87 (3H, m), 7.40 (1H, d), 7 .27-7.23 (1H, m), 4.32 (1H, t), 4.12 (2H, m), 3.44 -3.33 (2H, m), 1.82-1.76 (2H, m), 1.51-1.3 (6H).

To the 2 L four-necked flask was added the compound [O] obtained above (50.00 g, 173 mmol), dimethylaminophenol (46.23 g, 382 mmol), nitrobenzene (2.13 g, 17.3 mmol), and THF (500 g). After purging with nitrogen, the mixture was stirred with heating under reflux. A THF (100 g) solution of methacrylic acid chloride (38.1 g, 361 mmol) was gradually added dropwise thereto. After completion of the dropwise addition, the reaction was traced by HPLC. After confirming the completion of the reaction, the reaction solution was cooled to room temperature. Thereafter, the reaction solution was poured into 3 L of 1M aqueous hydrochloric acid, and the precipitated solid was filtered to obtain a crude product. Next, the obtained crude product was washed with an ethanol / hexane mixed solvent and then with acetone and then dried under reduced pressure to obtain 38.4 g of a polymerizable compound [RM6] (yield 62%).

The measurement result of the nuclear magnetic resonance (NMR) of the polymerizable compound [RM6] was as follows.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 8.63 (1H, s), 8.08 (1H, dd), 7.87 (1H, d), 7.76 (1H, d), 7.22-7.19 (1H, m), 7.16-7.15 (1H, m), 6.11-6.10 (1H, m), 5.56-5.54 (1H, m ), 4.20-4.10 (4H, m), 1.97-1.95 (3H, m), 1.92-1.85 (2H, m), 1.78-1.71 (2H) , M), 1.60-1.47 (4HH, m).

<Synthesis Example 7>
Synthesis of polymerizable compound [RM7] In a 500 ml eggplant flask equipped with a cooling tube, 14.9 g (80.0 mmol) of biphenol, 35 g (167.0 mmol) of 5-bromopentyl acetate, 41.5 g (300 mmol) of potassium carbonate, and 250 ml of acetone Was added to form a mixture, which was reacted at a temperature of 60 ° C. with stirring for 48 hours. After completion of the reaction, the reaction solution was poured into 600 ml of pure water to obtain 33.6 g of white solid compound [P] (yield 95%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [P] was as follows.
¹ H-NMR (CDCl ₃ ) δ: 1.57 (m, 4H), 1.74 (m, 4H), 1.86 (m, 4H), 2.06 (s, 6H), 4.02 ( t, 4H), 4.12 (t, 4H), 6.95 (d, 4H), 7.47 (d, 4H).

To a 1-liter eggplant flask equipped with a condenser tube, 250 ml of ethanol, 18.0 g (41 mmol) of the compound [P] obtained above, and 100 ml of 10% aqueous sodium hydroxide solution were added to form a mixture, and the mixture was stirred at a temperature of 85 ° C. for 5 hours. Reacted. After completion of the reaction, 500 ml of water and the reaction solution were added to a 1000 ml beaker and stirred for 30 minutes at room temperature, and then 80 ml of 10% HCl aqueous solution was added dropwise, followed by filtration to obtain 12.2 g of compound [Q] as a white solid. (Yield 83%).

The measurement result of the nuclear magnetic resonance (NMR) of the compound [Q] was as follows.
¹ H-NMR (DMSO-d6) δ: 1.46 (m, 8H), 1.71 (m, 4H), 3.41 (m, 4H), 3.98 (m, 4H), 4.39 (m, 2H), 6.96 (m, 4H), 7.51 (m, 4H).

Compound [Q] (5.0 g, 14.0 mmol) obtained above was dissolved in 30 ml of THF together with 3.2 g of triethylamine and a small amount of 2,6-di-tert-butyl-p-cresol (BHT) at room temperature. The mixture was stirred and a solution prepared by dissolving 3.3 g (32 mmol) of methacryloyl chloride in 20 ml of THF was added dropwise over 15 minutes while cooling with a water bath. After dropping, the mixture was stirred for 30 minutes, and the water bath was removed and stirring was continued overnight while returning to room temperature. After completion of the reaction, the reaction solution was poured into 200 ml of pure water and filtered to obtain a white solid. This solid was dissolved in chloroform and precipitated with hexane (hexane / chloroform = 2/1) to obtain 2.6 g of a white solid polymerizable compound [RM7] (yield 38%).

The measurement results of the nuclear magnetic resonance (NMR) of the polymerizable compound [RM7] were as follows.
¹ H-NMR (CDCl ₃ ) δ: 1.56 (m, 4H), 1.74 (m, 4H), 1.82 (m, 4H), 1.97 (s, 6H), 4.03 ( m, 4H), 4.20 (m, 4H), 5.55 (m, 2H), 6.10 (m, 2H), 6.94 (d, 4H), 7.45 (d, 4H).

<Measurement of molecular weight of polyimide>
The molecular weight measurement conditions for polyimide are as follows.
Apparatus: Room temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by Senshu Scientific Co., Ltd.
Column: Column made by Shodex (KD-803, KD-805)
Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, Tetrahydrofuran (THF) 10ml / L
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight of about 9,000,150,000, 100,000, 30,000) manufactured by Tosoh Corporation and polyethylene glycol (manufactured by Polymer Laboratories) Molecular weight about 12,000, 4,000, 1,000).

Moreover, the imidation ratio of polyimide was measured as follows. Add 20 mg of polyimide powder to an NMR sample tube (NMR sampling tube standard φ5 by Kusano Kagaku Co., Ltd.), add 1.0 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS mixture), and apply ultrasonic waves. To dissolve completely. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNW-ECA500) manufactured by JEOL Datum. The imidation rate is determined based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid appearing in the vicinity of 9.5 to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value. In the following formula, x is the proton peak integrated value derived from the NH group of the amic acid, y is the peak integrated value of the reference proton, and α is the proton of the NH group of the amic acid in the case of polyamic acid (imidation rate is 0%). This is the ratio of the number of reference protons to one.
Imidization rate (%) = (1−α · x / y) × 100

Example 1
BODA (10.0 g, 40.0 mmol), DBA (6.09 g, 40.0 mmol), PCH7 (11.5 g, 30.0 mmol), BEM-S (7.93 g, 30.0 mmol) were added to NMP (140. 7 g), and after reacting at 60 ° C. for 5 hours, CBDA (11.37 g, 58.0 mmol) and NMP (46.9 g) were added and reacted at 40 ° C. for 10 hours to obtain a polyamic acid solution. . After adding NMP to this polyamic acid solution (200 g) and diluting to 6% by mass, acetic anhydride (17.4 g) and pyridine (67.6 g) were added as an imidization catalyst, and the mixture was reacted at 50 ° C. for 3 hours. This reaction solution was poured into methanol (3000 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (A). The imidation ratio of this polyimide was 60%, the number average molecular weight was 12,000, and the weight average molecular weight was 26,000.

NMP (44.0 g) was added to the obtained polyimide powder (A) (6.0 g), and the mixture was dissolved by stirring at 50 ° C. for 5 hours. 3AMP (1 wt% NMP solution) 6.0g, NMP (14.0g), and BCS (30.0g) were added to this solution, and the liquid crystal aligning composition (B) was obtained by stirring at room temperature for 5 hours.

Further, 0.06 g (10% by mass with respect to the solid content) of the polymerizable compound RM1 obtained in Synthesis Example 1 was added to 10.0 g of the liquid crystal alignment composition (B), and the mixture was stirred at room temperature for 3 hours. And dissolved to prepare a liquid crystal aligning agent (B1).

(Example 2)
The liquid crystal aligning agent (B2) was subjected to the same operation as in Example 1 except that [RM2] obtained in Synthesis Example 2 was used instead of the polymerizable compound [RM1]. ) Was prepared.

Example 3
The liquid crystal aligning agent (B3) was subjected to the same operation as in Example 1 except that [RM3] obtained in Synthesis Example 3 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (B). ) Was prepared.

Example 4
The liquid crystal aligning agent (B4) was subjected to the same operation as in Example 1 except that [RM4] obtained in Synthesis Example 4 was used instead of the polymerizable compound [RM1]. ) Was prepared.

(Example 5)
The liquid crystal aligning agent (B5) was subjected to the same operation as in Example 1 except that [RM5] obtained in Synthesis Example 5 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (B). ) Was prepared.

(Example 6)
A liquid crystal aligning agent (B6) was prepared in the same manner as in Example 1 except that [RM6] obtained in Synthesis Example 6 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (B). ) Was prepared.

(Comparative Example 1)
The liquid crystal aligning agent (B7) was subjected to the same operation as in Example 1 except that [RM7] obtained in Synthesis Example 7 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (B). ) Was prepared.

(Example 7)
BODA (10.0 g, 40.0 mmol), DBA (5.3 g, 35.0 mmol), m-PCH7 (12.0 g, 30.0 mmol), BEM-S (9.2 g, 35.0 mmol) were added to NMP ( 144.5 g), and after reacting at 60 ° C. for 5 hours, CBDA (11.5 g, 58.5 mmol) and NMP (48.2 g) were added and reacted at 40 ° C. for 10 hours to obtain a polyamic acid solution. Obtained. After adding NMP to this polyamic acid solution (200 g) and diluting to 6% by mass, acetic anhydride (17.0 g) and pyridine (65.8 g) were added as imidization catalysts, and the mixture was reacted at 50 ° C. for 3 hours. This reaction solution was poured into methanol (3000 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (C). The imidation ratio of this polyimide was 60%, the number average molecular weight was 14,000, and the weight average molecular weight was 47,000.

NMP (44.0 g) was added to the obtained polyimide powder (C) (6.0 g), and the mixture was dissolved by stirring at 50 ° C. for 5 hours. 3AMP (1 wt% NMP solution) 6.0g, NMP (14.0g), and BCS (30.0g) were added to this solution, and the liquid crystal aligning composition (D) was obtained by stirring at room temperature for 5 hours.

In addition, 0.06 g (10% by mass with respect to the solid content) of the polymerizable compound [RM1] obtained in Synthesis Example 1 was added to 10.0 g of the above liquid crystal alignment composition (D), and 3 at room temperature. The liquid crystal aligning agent (D1) was prepared by stirring for a time and dissolving.

(Example 8)
The liquid crystal aligning agent (D2) was subjected to the same operation as in Example 7 except that [RM2] obtained in Synthesis Example 2 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (D). ) Was prepared.

Example 9
The liquid crystal aligning agent (D3) was subjected to the same operation as in Example 7 except that [RM3] obtained in Synthesis Example 3 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (D). ) Was prepared.

(Example 10)
The liquid crystal aligning agent (D4) was subjected to the same operation as in Example 7 except that [RM4] obtained in Synthesis Example 4 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (D). ) Was prepared.

(Comparative Example 2)
The liquid crystal aligning agent (D5) was subjected to the same operation as in Example 7 except that [RM7] obtained in Synthesis Example 7 was used instead of the polymerizable compound [RM1] for the liquid crystal aligning composition (D). ) Was prepared.

<Storage stability test>
The liquid crystal aligning agents obtained in Examples 1 to 10 and Comparative Examples 1 and 2 were stored in a freezer at −20 ° C. for 1 week, and then visually checked for precipitates and the like. Those having no precipitates were considered to have good storage stability. Table 2 shows the composition of the liquid crystal aligning agent and the results of the storage stability test.

As shown in Table 2, the liquid crystal alignment agents (B1) to (B6) of Examples 1 to 6 containing the polymerizable compounds [RM1] to [RM6] in the liquid crystal alignment composition (B) were precipitated. Since there was no thing etc., it turned out that storage stability is favorable. On the other hand, precipitates were generated in the liquid crystal aligning agent (B7) of Comparative Example 1 containing the polymerizable compound [RM7] in the liquid crystal aligning composition (B).

Similarly, the liquid crystal alignment agents (D1) to (D4) of Examples 7 to 10 containing the polymerizable compounds [RM1] to [RM4] in the liquid crystal alignment composition (D) are completely free of precipitates and the like. Although it was not, the deposit generate | occur | produced in the liquid crystal aligning agent (D5) of the comparative example 2 which contained polymeric compound [RM7] in the liquid crystal aligning agent (D).

From the above results, the liquid crystal aligning agents of Examples 1 to 10 contain polymerizable compounds [RM1] to [RM6] having functional groups capable of hydrogen bonding, that is, carboxyl groups, and thus have solubility in solvents. It is considered that no precipitates were generated even after being stored in a freezer at −20 ° C. for 1 week. Therefore, it was found that the storage stability of the liquid crystal aligning agent can be improved by making the polymerizable compound used for the liquid crystal aligning agent a polymerizable compound having a hydrogen-bonding functional group such as a carboxyl group.

In addition, the polymerizable compounds [RM1] to [RM6] having a carboxyl group form a hydrogen bond between molecules and form a huge mesogen structure, so that absorption extends to the long wavelength side of the ultraviolet region, and sensitivity to ultraviolet rays. Therefore, it is considered that the response speed was increased in the response speed measurement described later.

<Production of liquid crystal cell>
(Example 11)
Using the liquid crystal aligning agent (B1) obtained in Example 1, a liquid crystal cell was prepared according to the procedure shown below.

The liquid crystal aligning agent (B1) obtained in Example 1 was spin-coated on the ITO surface of an ITO electrode substrate on which an ITO electrode pattern having a pixel size of 100 μm × 300 μm and a line / space of 5 μm was formed, After drying for 90 seconds on this hot plate, baking was performed in a hot air circulation oven at 200 ° C. for 30 minutes to form a liquid crystal alignment film having a thickness of 100 nm.

Moreover, after spin-coating the liquid crystal aligning agent (B1) on the ITO surface in which the electrode pattern is not formed and drying for 90 seconds on a hot plate at 80 ° C., baking is performed in a hot air circulation oven at 200 ° C. for 30 minutes, A liquid crystal alignment film having a thickness of 100 nm was formed.

After spraying a 4 μm bead spacer on the liquid crystal alignment film of one of the two substrates, a sealant (solvent type thermosetting epoxy resin) was printed thereon. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was faced inward and bonded to the previous substrate, and then the sealing agent was cured to produce an empty cell. Liquid crystal MLC-6608 (trade name, manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method to produce a liquid crystal cell.

Example 12
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (B2) was used instead of the liquid crystal aligning agent (B1).

(Example 13)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (B3) was used instead of the liquid crystal aligning agent (B1).

(Example 14)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (B4) was used instead of the liquid crystal aligning agent (B1).

(Example 15)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (B5) was used instead of the liquid crystal aligning agent (B1).

(Example 16)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (B6) was used instead of the liquid crystal aligning agent (B1).

(Example 17)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (D1) was used instead of the liquid crystal aligning agent (B1).

(Example 18)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (D2) was used instead of the liquid crystal aligning agent (B1).

(Example 19)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (D3) was used instead of the liquid crystal aligning agent (B1).

(Example 20)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (D4) was used instead of the liquid crystal aligning agent (B1).

(Comparative Example 3)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (B7) was used instead of the liquid crystal aligning agent (B1).

(Comparative Example 4)
A liquid crystal cell was produced in the same manner as in Example 11 except that the liquid crystal aligning agent (D5) was used instead of the liquid crystal aligning agent (B1).

<Measurement method of response speed>
The response speed of the liquid crystal cells obtained in Examples 11 to 20, Comparative Example 3 and Comparative Example 4 to UV irradiation was measured by the following method.

First, a liquid crystal cell was placed between a pair of polarizing plates in a measuring device configured in the order of a backlight, a pair of polarizing plates in a crossed Nicol state, and a light quantity detector. At this time, the ITO electrode pattern in which the line / space was formed was at an angle of 45 ° with respect to the crossed Nicols. Then, a rectangular wave having a voltage of ± 6 V and a frequency of 1 KHz is applied to the liquid crystal cell, and the change until the luminance observed by the light amount detector is saturated is captured by an oscilloscope, and the luminance when no voltage is applied is obtained. A voltage of 0% and ± 4 V was applied, the saturated luminance value was set to 100%, and the time taken for the luminance to change from 10% to 90% was defined as the response speed.

Thereafter, with a DC voltage of 10 V applied to the liquid crystal cell, 10 J UV irradiation through a 365 nm band pass filter was applied from the outside of the liquid crystal cell. Thereafter, the response speed was measured again, and the response speed before and after UV irradiation was compared. Table 3 shows the response speed measurement results.

<Measurement of pretilt angle>
For the liquid crystal cells obtained in Examples 11 to 20, Comparative Example 3 and Comparative Example 4, the pretilt angle of the pixel portion after UV irradiation was measured. As a measuring apparatus, an LCD analyzer LCA-LUV42A manufactured by Meiryo Technica was used. Table 3 shows the measurement results of the pretilt angle.

As shown in Table 3, the liquid crystal cells of Examples 11 to 20 were obtained from liquid crystal aligning agents containing polymerizable compounds [RM1] to [RM6] having functional groups capable of hydrogen bonding, that is, carboxyl groups. It is a thing. In these liquid crystal cells, it is considered that a huge mesogen structure was formed in the liquid crystal alignment film due to hydrogen bonding caused by the carboxyl group. The liquid crystal cells of Examples 11 to 20 are sensitive to ultraviolet light (365 nm) on the long wavelength side due to the influence of this huge mesogen structure, and sufficiently fast response speed (17 to 35 msec) even when irradiated with 365 nm ultraviolet light. ) Was achieved. Further, since the liquid crystal cells of Examples 11 to 20 obtained a high pretilt angle, it was found that the liquid crystal aligning agent used in the production of these liquid crystal cells can impart excellent alignment fixing ability. .

On the other hand, the liquid crystal cells of Comparative Example 3 and Comparative Example 4 were obtained from a liquid crystal aligning agent to which a polymerizable compound [RM7] having no functional group capable of hydrogen bonding was added. These liquid crystal cells have a simple biphenyl structure in the mesogen portion of the liquid crystal alignment film, so there is almost no sensitivity to ultraviolet light (365 nm) on the long wavelength side, and a sufficient response speed can be obtained by irradiation with 365 nm ultraviolet light. I could not.

Furthermore, since the polymerizable compound [RM7] does not have a functional group capable of hydrogen bonding in the molecule, the solubility in a solvent is low, and the polymerizable compound [RM7] was precipitated during freezing.

From the above results, by containing the polymerizable compounds [RM1] to [RM6] having a carboxyl group, a sufficiently fast response speed can be achieved even with ultraviolet light on the long wavelength side, and excellent alignment fixing ability is imparted. It was found that a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element that can be realized are realized.

Furthermore, since the polymerizable compounds [RM1] to [RM6] having a carboxyl group do not remain in the solvent, the storage stability of the liquid crystal aligning agent can be improved by containing these polymerizable compounds. It was found that the sensitivity to ultraviolet rays can be improved.

Since the liquid crystal aligning agent of the present invention contains a highly soluble polymerizable compound, it is possible to obtain a liquid crystal aligning film having an alignment fixing ability excellent in light sensitivity. Therefore, the liquid crystal display element having the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention has excellent reliability, can be suitably used for a large-screen, high-definition liquid crystal television, etc. VA mode, TN mode, OCB mode, etc.) and various liquid crystal display elements adopting a horizontal electric field drive mode (IPS mode, FFS mode). In particular, it is useful for a liquid crystal display element having a liquid crystal alignment film that controls the alignment of liquid crystal by irradiating ultraviolet rays or polarized ultraviolet rays.

Claims

Containing a polymer, a polymerizable compound, and a solvent;
The polymerizable compound has a polymerizable unsaturated bond group, a functional group that forms a hydrogen bond, and at least one aromatic ring in the vicinity of the functional group, and the functional group forms a hydrogen bond between molecules. A liquid crystal aligning agent characterized by forming a mesogenic structure.
The liquid crystal aligning agent according to claim 1, wherein the functional group is a carboxyl group.
3. The liquid crystal aligning agent according to claim 1, wherein the polymerizable compound is at least one selected from the following formulas [1-1] to [1-4].

(T is an ether, ester, amide bond, S is an alkylene group having 2 to 11 carbon atoms, R is a hydrogen atom or a methyl group, n = 1 or 2)
The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the polymerizable compound is at least one selected from the following formulas [2-1] to [2-6].
The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the polymer has a group in the side chain that vertically aligns the liquid crystal.
The liquid crystal aligning agent according to claim 5, wherein the polymer further has a photopolymerizable group in a side chain.
7. The liquid crystal aligning agent according to claim 6, wherein the photopolymerizable group is at least one selected from the following formulas [3-1] to [3-7].

(In the formula, Me represents a methyl group.)
The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the polymer has a photoreactive group.
9. The liquid crystal aligning agent according to claim 8, wherein the photoreactive group is at least one selected from the following formulas [4-1] to [4-5].
The polymer according to any one of claims 1 to 9, wherein the polymer contains at least one selected from a polyimide precursor and a polyimide obtained by imidization thereof, polysiloxane or poly (meth) acrylate. The liquid crystal aligning agent of description.
A liquid crystal alignment film produced using the liquid crystal aligning agent according to any one of claims 5 to 7 and obtained through a step of irradiating ultraviolet rays while applying a voltage.
A liquid crystal display element comprising the liquid crystal alignment film according to claim 11.
A liquid crystal alignment film produced using the liquid crystal aligning agent according to claim 8 or 9 and obtained through a step of irradiating polarized ultraviolet rays.
A liquid crystal display element comprising the liquid crystal alignment film according to claim 13.