Weakly anchoring liquid-crystal alignment agent, liquid-crystal display element, and polymer

Abstract

Provided is a weak anchoring liquid crystal alignment agent which is used for forming a liquid crystal alignment film of a liquid crystal cell that has liquid crystals and the liquid crystal alignment film, and which comprises: at least one polymer (A) that is selected from the group consisting of polyamic acids, polyamic acid esters, polyimides, polyamides, and polyuria; and a polymer (B) that is compatible with the liquid crystals and that exhibits weak anchoring properties, said weak anchoring liquid crystal alignment agent containing a graft copolymer in which the polymer (A) and the polymer (B) are bonded.

Description

Weak anchoring liquid crystal alignment agent, liquid crystal display element, and polymer

[0001] The present invention relates to a liquid crystal display element that can produce an organic film (weak anchoring film) that exhibits weak anchoring properties using an inexpensive method that does not involve complicated processes, thereby achieving even higher brightness and lower driving voltage, as well as a weak anchoring liquid crystal alignment agent and polymer that can be used for such an element.

[0002] In recent years, liquid crystal display elements have been widely used in displays for mobile phones, computers, televisions, and the like. Liquid crystal display elements have characteristics such as thinness, light weight, and low power consumption, and are expected to be applied to further content in the future, such as virtual reality (VR) and ultra-high-definition displays. Various display modes have been proposed for liquid crystal displays, including twisted nematic (TN) mode, in-plane switching (IPS) mode, and vertical alignment (VA) mode, but all display modes use a film (liquid crystal alignment film) that guides liquid crystals into a desired alignment state.

[0003] In particular, the IPS system is preferred for products equipped with touch panels, such as tablet PCs, smartphones, and smart TVs, as it is less likely to distort the display when touched. In recent years, liquid crystal display elements using the FFS (Fringe Field Switching) system and liquid crystal alignment technology using photoalignment methods have been used to improve contrast and viewing angle characteristics.

[0004] However, the FFS method has issues with higher substrate manufacturing costs than the IPS method and the occurrence of a specific display defect called Vcom shift. Furthermore, while the photo-alignment method has advantages over the rubbing alignment method in that it is easier to adapt to the expansion of elements and can significantly improve display characteristics, it also has issues inherent to its principles (display defects caused by decomposition products when using photodegradable materials, image sticking due to insufficient alignment force when using photoisomerization materials, etc.). Currently, LCD element manufacturers and LCD alignment film manufacturers are devising various solutions to solve these issues.

[0005] In recent years, it has been discovered that by forming a compatible interface between the polymer and the liquid crystal (a liquid-liquid interface in a completely wet state) at the contact interface between the liquid crystal and the substrate in liquid crystal cells, a "zero-plane anchoring" state without orientation restricting force in the in-plane direction can be created, and liquid crystal switching devices with no switching threshold and orientation memory properties have been reported (see Patent Document 1).

[0006] A weak-anchoring IPS method has been proposed that utilizes weak-anchoring technology. Compared to conventional IPS methods, this method can achieve improved contrast ratio and significantly lower voltage operation (see Patent Document 2).

[0007] The weak anchoring IPS method is created by using a liquid crystal alignment film with strong anchoring energy on one side of the substrate, and a thin film with no anchoring energy on the other side of the substrate (equipped with electrodes that generate a transverse electric field).

[0008] In recent years, a weak anchoring IPS method has been proposed that uses a method of directly attaching a dense polymer brush to the substrate (see Patent Document 3).

[0009] As an alternative method, a weak anchoring IPS method has been proposed, which involves using a liquid crystal alignment film capable of generating photoradicals and a compound capable of radical polymerization, and then irradiating the liquid crystal with UV light to induce a radical reaction and achieve weak anchoring (see Patent Document 4). This technology enables mass production and achieves improved contrast ratio, low voltage drive, high-speed response, and reduced burn-in.

[0010] Furthermore, as alternative methods, the present inventors have proposed a coating material consisting of a block copolymer having block segments compatible with liquid crystals and block segments insoluble in liquid crystals or insoluble by heating (see Patent Document 5), a coating material consisting of a graft copolymer having branch polymers compatible with liquid crystals and stem polymers insoluble in liquid crystals or insoluble by heating (see Patent Document 6), and a coating material consisting of a polymer alloy of these with polyamic acid, polyamic acid ester, or polyimide (see Patent Document 7). The features of these inventions are that they are completed by coating and firing alone and exhibit good weak anchoring characteristics, and these technologies have realized a weak anchoring technology that is low cost and has a small process load.

[0011] Japanese Patent Publication No. 2006-84536, Japanese Patent Publication No. 2013-231757, Japanese Patent Publication No. 2018-028621, International Publication No. 2019 / 004433, International Publication No. 2022 / 260048, International Publication No. 2023 / 048278, International Publication No. 2024 / 058164

[0012] The method of directly attaching a concentrated polymer brush to a substrate (Patent Document 3) is technically difficult and impractical from a mass production standpoint because it requires a surface treatment step to create reaction sites on the substrate and a step to grow the polymer from the reaction sites on the substrate surface, making the process complex, and because it requires highly advanced deoxygenation conditions, necessitating strict environmental control. Therefore, a method has been proposed to obtain a weakly anchored IPS display element by coating a bottle brush polymer with adhesive sites onto a substrate. However, when manufacturing the bottle brush polymer, macromonomers with polymerization initiation sites are used, and both are manufactured using living radical polymerization, making large-scale supply difficult. In addition, bottle brush polymers have poor solvent selectivity and low solubility in commonly used solvents such as N-methyl-2-pyrrolidone (NMP) and γ-butyrolactone (GBL), which poses a significant challenge in commonly used coating processes. Furthermore, due to their structure, they have poor sealing and adhesion to the substrate, so it is necessary to consider methods that can solve these problems.

[0013] In the method of weak anchoring using photoradical polymerization and radically polymerizable compounds, the evaporation of polymerizable additives in the high vacuum state during liquid crystal injection can lead to variations in properties and poor reproducibility. Furthermore, the need for UV irradiation after liquid crystal element fabrication increases the process load and poses other issues, such as the degradation of the liquid crystal composition due to UV exposure.

[0014] Coating materials (see Patent Document 7) made of a polymer alloy of a block copolymer (see Patent Document 5) or a graft copolymer (see Patent Document 6) with a polyamic acid, a polyamic acid ester, or a polyimide can solve the problems of mass productivity, processability, coatability, etc., as described above. However, since the phase separation between the two components affects the quality of the properties, the coating materials are highly dependent on the baking method and baking temperature, and are thought to deteriorate the process margin.

[0015] Patent Document 4 proposes a weak anchoring liquid crystal display device that utilizes a graft copolymer (called a polymer brush) with a high density of branch polymers obtained by living polymerization. The polymer brush is synthesized using a technique called the "grafting from" method, which requires the use of living polymerization. Attempts have been made to improve adhesion between the substrate and the polymer by introducing groups into the branch polymer that contribute to improved adhesion to the substrate. However, introducing too many groups into the branch polymer may impair the weak anchoring properties. Furthermore, the extremely high density of the branch polymer may hinder solvation with the solvent, potentially impairing its affinity for solvents with high boiling points and relatively high polarity, such as NMP and γ-butyrolactone. The inventors have also investigated weak anchoring liquid crystal alignment agents using block copolymers obtained by living polymerization instead of polymer brushes. However, both experiments resulted in poor solvent selectivity and adhesion strength, which is considered to be a common issue for precisely synthesized polymers, including polymer brushes.

[0016] If these technical challenges can be resolved, panel manufacturers will be able to easily and efficiently produce weakly anchored IPS liquid crystal display elements, which offer advantages such as reduced battery power consumption and improved image quality.

[0017] The present invention has been made to solve the above-mentioned problems, and aims to provide a weak anchoring liquid crystal alignment agent and a liquid crystal display element that can be easily manufactured, have good coatability, have little dependency on the baking method or baking temperature, and can produce a weak anchoring liquid crystal alignment film that can simultaneously achieve low-voltage driving and high-speed response when the voltage is turned off.

[0018] The present inventors conducted extensive research to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved, and completed the present invention having the following gist. That is, the present invention includes the following: [1] A weak anchoring liquid crystal aligning agent used for forming a liquid crystal alignment film of a liquid crystal cell having liquid crystal and the liquid crystal alignment film, the weak anchoring liquid crystal aligning agent containing at least one polymer (A) selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, and a polymer (B) that is compatible with the liquid crystal and exhibits weak anchoring properties, and containing a graft copolymer in which the polymer (A) and the polymer (B) are bonded. [2] The weak anchoring liquid crystal aligning agent according to [1], wherein a grafting ratio of the graft copolymer is 15% or more. [3] The weak anchoring liquid crystal aligning agent according to [1] or [2], wherein the polymer (B) is derived from a polymer (B1) having a group L capable of covalently bonding to the polymer (A), selected from the group consisting of a hydroxy group, a phenol group, an optionally protected amino group, an optionally protected aniline group, an optionally protected thiol group, an optionally protected thiophenol group, an epoxy group, an oxetane group, an allyl group, a vinyl group, a methacryl group, an acrylic group, an oxazoline group, an optionally protected isocyanate group, and an aldehyde group, in a side chain structure. [4] The weak anchoring liquid crystal aligning agent according to any one of [1] to [3], wherein a monomer constituting the polymer (B) includes a monomer selected from the group consisting of the following formulas (1), (2), (3), and (4): (In formula (1), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, X represents a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, or thioether bond, R １represents an alkyl group having 1 to 20 carbon atoms, into which a bonding group may be inserted, and n is an integer of 1 to 2. When n is 2, two X and R １ may be the same or different.) (In formula (2), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, S represents a single bond or a saturated hydrocarbon group of 1 to 6 carbon atoms which may have a bonding group inserted therein, T represents an organic group represented by the following formula (2-T), and n is an integer of 1 to 2. When n is 2, the two Ts may be the same or different. However, when n is 2, S represents a saturated hydrocarbon group of 1 to 6 carbon atoms which may have a bonding group inserted therein.) (In formula (2-T), * indicates a bonding site. X is a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, thioether bond, -Si(R) １ ) (R ２ )-(R １ and R ２ each independently represents an alkyl group bonded to Si.), —Si(R ３ ) (R ４ )-O-(R ３ and R ４ each independently represents an alkyl group bonded to Si. ５ )-(R ５ represents a hydrogen atom or an alkyl group bonded to N; and Cy represents a non-aromatic cyclic group having 6 to 20 members. (In formula (3), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, R １ The 'X' represents an aliphatic hydrocarbon group having a linear or branched structure with 1 to 10 carbon atoms, and each of the three 'X's independently represents a hydrogen atom or the following formula (3-X). However, at least one of the three 'X's represents the formula (3-X). (In formula (3-X), Y represents a single bond, -O-, -S-, or -N(R)- (where R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms bonded to N), and * indicates a bonding site. ２ , R ３ , and R ４each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have a substituent. (In formula (4), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ ~R ３ each independently represents a single bond or an alkylene group having 1 to 6 carbon atoms into which a bonding group may be inserted; Ar represents an aromatic hydrocarbon group which may have a substituent; X １ and X ２ each independently represents a hydrogen atom or an aromatic hydrocarbon group which may have a substituent, R １ X １ and R ２ X ２ and R １ X １ and R ２ X ２ and the carbon atom bonded to R may form a ring together. １ X １ , R ２ X ２ and R ３ The total number of carbon atoms in the formulas (1), (2), (3), and (4) is 1 or more. [5] The weak anchoring liquid crystal aligning agent according to [4], wherein M in the formulas (1), (2), (3), and (4) is each independently any of the structures represented by the following formulas: (In the formula, R １ , and R ２ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, and X, Y, and Z each independently represent an oxygen atom or a sulfur atom. １ and * ２ represents a binding site, * １ and * ２Either of the two may be replaced by a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms. n represents an integer from 1 to 5.) [6] A graft copolymer used for forming the liquid crystal alignment film of a liquid crystal cell having a liquid crystal and a liquid crystal alignment film, comprising at least one polymer (A) selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, and a polymer (B) that is compatible with the liquid crystal and exhibits weak anchoring properties, wherein the polymer (A) and the polymer (B) are bonded together. [7] A liquid crystal display element obtained using the weak anchoring liquid crystal alignment agent described in any of [1] to [5]. [8] The liquid crystal display element described in [7], which is a transverse electric field liquid crystal display element.

[0019] According to the present invention, a stable weakly anchored liquid crystal alignment film can be manufactured using an extremely simple method compared to the conventional technology. This makes it possible to reduce the process load and improve the yield in the actual industrialization of weakly anchored transverse field liquid crystal display elements. Furthermore, by using the materials and methods of the present invention, it is possible to achieve faster response when the voltage is turned off, reduced burn-in, expanded process margins based on firing temperature dependence, and high backlight transmittance and low voltage driving in low-temperature environments compared to the conventional technology. Thus, it is possible to provide materials and transverse field liquid crystal display elements that can stably exhibit excellent characteristics.

[0020] 1 is a schematic cross-sectional view showing an example of a horizontal electric field liquid crystal display element of the present invention, and FIG. 2 is a schematic cross-sectional view showing another example of a horizontal electric field liquid crystal display element of the present invention.

[0021] (Weak anchoring, weakly anchored liquid crystal alignment film) In the present invention, "weak anchoring" means that although it has the force to restrict the orientation of liquid crystal molecules with respect to the substrate in the azimuthal or polar angular direction, it has no anchoring strength (i.e., interfacial elastic energy that maintains the position of liquid crystal molecules or returns them to their original state even if the orientation of liquid crystal molecules changes), or if it does have any strength, it is weaker than the intermolecular forces between liquid crystals, and in the weak anchoring of the present invention, the azimuthal anchoring strength (A ２ ) is 10 －５ [J / m ２This refers to cases where the value is smaller than [ ]. Furthermore, "weakly anchored liquid crystal alignment film" refers to a film that forms a weakly anchored state by contacting liquid crystal, and is not limited to solid films but also includes liquid films that cover solid surfaces.

[0022] (Strong anchoring, strong anchoring liquid crystal alignment film) In the present invention, "strong anchoring" means that the liquid crystal molecules are oriented in a uniaxial direction and can maintain the orientation of the liquid crystal even when external energy is applied, or that the liquid crystal molecules have an anchoring strength that can return them to their original position even if their orientation changes. In the strong anchoring of the present invention, the azimuthal anchoring strength (A ２ ) is 10 －４ [J / m ２ This refers to cases where the value is greater than [ ]. Furthermore, "strongly anchoring liquid crystal alignment film" refers to a film that forms a strongly anchoring state by contacting liquid crystal, and is not limited to solid films but also includes liquid films that cover solid surfaces.

[0023] (Weak Anchoring Liquid Crystal Display Element) A weak anchoring liquid crystal display element can be fabricated by applying the above-defined weak anchoring liquid crystal alignment film and strong anchoring liquid crystal alignment film to substrates with electrodes and laminating them together in pairs. In a weak anchoring liquid crystal display element, the azimuthal anchoring strength of one of the liquid crystal alignment films is extremely small, so that a weak electric field or external field energy can induce a change in the alignment of the liquid crystal, and it is possible to change the alignment of liquid crystal molecules in areas where they normally do not move. Therefore, in display elements using comb-tooth electrodes such as IPS and FFS, even liquid crystal molecules on electrodes with weak electric field strength can be driven, and therefore higher transmittance and lower driving voltage can be achieved compared to liquid crystal display elements in which both alignment films in the pair are composed of strong anchoring liquid crystal alignment films.

[0024] Azimuthal anchoring strength is an index that represents the strength of the interfacial elastic energy between liquid crystal molecules and liquid crystal alignment films in the azimuthal direction. Methods used to calculate azimuthal anchoring strength include the torque balance method, the strong electric field method, the geometry method (external field application method), and the Fredericks transition method.

[0025] (Graft Copolymer) One embodiment of the "graft copolymer" of the present invention is a graft copolymer contained in a weak anchoring liquid crystal aligning agent. The weak anchoring liquid crystal aligning agent is used to form a film that aligns liquid crystals used in liquid crystal display elements, i.e., a liquid crystal alignment film. The weak anchoring liquid crystal aligning agent is also used to form a liquid crystal alignment film for a liquid crystal cell having liquid crystals and a liquid crystal alignment film. The graft copolymer includes at least one polymer (A) selected from the group consisting of polyamic acid esters, polyimides, polyamides, and polyureas, and a polymer (B) that is compatible with the liquid crystal and exhibits weak anchoring properties. In the graft copolymer, the polymer (A) and the polymer (B) are bonded together. The bond here is a covalent bond. The graft copolymer includes a trunk polymer and a branch polymer bonded to the trunk polymer as a side chain of the trunk polymer. The graft copolymer includes, for example, the trunk polymer (A) and the branch polymer (B).

[0026] A graft copolymer refers to a polymer in which different polymers are bonded together by covalent bonds. Examples of different polymers include a combination of at least one polymer (A) selected from the group consisting of polyamic acid esters, polyimides, polyamides, and polyureas, and a polymer (B) obtained by polymerization of polymerizable unsaturated hydrocarbon groups. An example of a graft copolymer is a polymer having a branched structure, which simultaneously has a polymer corresponding to the "stem" and polymers corresponding to the "branches" bonded to the stem as side chains. Another example of a graft copolymer is a polymer obtained by polymerizing a second polymer using the side chains or ends of a first polymer as polymerization initiation ends. In this case, the first polymer is called the "stem polymer" and the second polymer is called the "branch polymer". Another example of a graft copolymer is a polymer obtained by bonding the side chains or ends of a first polymer to the side chains or ends of a second polymer. In this case, in the graft copolymer, the polymer with a larger mass proportion is called the "stem polymer," and the polymer with a smaller mass proportion is called the "branch polymer." The graft copolymer of the present invention comprises, for example, a branch polymer compatible with liquid crystals and a stem polymer selected from polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea. That is, the branch polymer compatible with liquid crystals contributes to the formation of a weak anchoring state by becoming compatible with and swelling with the liquid crystal, while the stem polymer selected from polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, which is not compatible with liquid crystals, prevents the graft copolymer from eluting into the liquid crystal. Furthermore, by adhering to the substrate, crosslinking between polymers, and crosslinking with sealing components, a weak anchoring liquid crystal display element with excellent film hardness and seal adhesion strength can be obtained. Furthermore, the graft copolymer of the present invention comprises a polymer selected from polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea as the core polymer, which is highly reliable and effective in improving various properties such as coatability, seal adhesion, electrical properties, refractive index modulation, and volume resistivity modulation. Therefore, it provides a liquid crystal alignment film with good coatability, good seal adhesion, high reliability, and the ability to modulate refractive index and volume resistivity.The present inventors have also previously disclosed a polymer alloy coating material (see WO 2024 / 058164) that mixes a component that exhibits weak anchoring properties with polyamic acid, polyamic acid ester, polyimide, polyamide, polyurea, or the like. This material is obtained by mixing two or more components that include a component that exhibits weak anchoring properties and an auxiliary component that improves coatability, seal adhesion, reliability, and the like. By their very nature, the weak anchoring properties-exhibiting component is a material system with low polarity and a high thermal expansion coefficient, while the auxiliary component is often a material system with high polarity and a low thermal expansion coefficient. Controlling phase separation (the distribution of the two components in the film) during the formation of a coating film of a liquid crystal alignment agent containing these two components is extremely difficult. Therefore, adjusting the appropriate mixing ratio and solvent system is important from a materials perspective, and a management system such as appropriate temperature control is important from a manufacturing perspective. In contrast, in the graft copolymer of the present invention, the component that exhibits weak anchoring properties and the auxiliary component are connected by a covalent bond, so there is no concept of phase separation between the two components, and even if there is some variation in the baking temperature or time, the properties do not deteriorate, providing a material system with a wide process margin.

[0027] A preferred embodiment of the graft copolymer used in the weak anchoring liquid crystal aligning agent of the present invention is characterized by using a polymerizable compound (hereinafter referred to as a macromonomer), which is an active polymer that chemically reacts with a trunk polymer at a pre-polymerized terminal or side chain structure, to synthesize a graft copolymer with a low branch polymer density (the grafting-to method), and introducing a highly polar or rigid group or crosslinking group, such as polyamic acid, polyamic acid ester, polyimide, polyamide, or polyurea, into the trunk polymer side. Here, it is known that the weak anchoring component responsible for the overall alignment characteristics of a weak anchoring liquid crystal alignment film is highly dependent on the composition of the weak anchoring component (molecular weight, molecular weight distribution, etc.). Therefore, from the viewpoint of material properties and reproducibility, it is most preferable to use a method in which the weak anchoring component is formed in advance and then bonded to an auxiliary component (the grafting-to method). However, since polymers similar to those obtained by the grafting-to method described above can also be synthesized using a technique for forming a trunk polymer using a polymer reaction (the grafting-from method), the synthesis method is not particularly limited.

[0028] In the weakly anchoring liquid crystal alignment agent of the present invention, it is preferable to use the compounds represented by formula (1), formula (2), formula (3), and formula (4), described later, as monomers constituting the branched polymer that exhibits weak anchoring properties by being compatible with liquid crystals.

[0029] The applicant has identified and filed patent applications for radical polymerizable compounds contained in a liquid crystal composition that can stably produce weakly anchored transverse field liquid crystal display elements without generating a pre-tilt angle, and which contribute to the generation of weak anchoring, specifically the compounds represented by formula (1), formula (2), formula (3), and formula (4) described below (WO2022 / 030602, WO2022 / 071286, WO2022 / 196565, WO2019 / 004433. By reference herein, the contents of these applications and publications are incorporated herein to the same extent as if they were fully expressed).

[0030] Furthermore, the applicant has discovered and filed a patent application (WO2022 / 260048) for a transverse electric field liquid crystal display element that provides a weak anchoring liquid crystal alignment agent containing block copolymers or graft copolymers synthesized from the aforementioned radical polymerizable compound, which enables the simpler and more stable production of weak anchoring films compared to conventional methods, and that enables stable low-voltage driving and high-speed response when the voltage is turned off simultaneously without the generation of a pre-tilt angle even in a narrow cell gap, and that reduces burn-in, thereby achieving both high backlight transmittance and low-voltage driving in a low-temperature environment.

[0031] An example of the graft copolymer of the present invention has a branch polymer that is compatible with the liquid crystal and a trunk polymer selected from polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, where the trunk polymer makes the graft copolymer incompatible with the liquid crystal.

[0032] The grafting ratio of the graft copolymer is not particularly limited, but is preferably 15% or more, more preferably 30% or more. The upper limit of the grafting ratio is not particularly limited, but may be, for example, 100% or less, 90% or less, or 80% or less. Here, the grafting ratio is an index indicating the reaction rate between polymer (A) and polymer (B). The grafting ratio is calculated from the following formula (eq2):

[0033] (Peak Intensity Before Grafting) The (peak intensity before grafting) in (eq. 2) is the peak intensity of a 1.0 wt % hexane solution of the polymer (B) used in the synthesis of the graft copolymer, as determined by THF-GPC.

[0034] (Peak intensity after grafting) In (eq. 2), the (peak intensity after grafting) is the residual peak of polymer (B) contained in the reaction solution after grafting. The residual peak intensity of polymer (B) is calculated by the following method. 1.0 g of hexane was added to 1.0 g of the reaction solution after grafting, and the mixture was stirred at room temperature for 1 hour to separate into aggregates containing the residue of the graft copolymer or polymer (A) and a liquid containing the residue of polymer (B) soluble in hexane. Furthermore, this liquid was filtered using a filter with 0.1 μm pores and measured by THF-GPC. The peak intensity at the discharge time corresponding to polymer (B) in the GPC chart was used as (peak intensity after grafting). GPC measurement can be performed by the method described in the Examples.

[0035] (Branch Polymer) In one embodiment, polymer (B), which is a branch polymer of the graft copolymer of the present invention, contributes to the formation of a weak anchoring state by being miscible with the liquid crystal and swelling therewith. The structure of the branch polymer miscible with the liquid crystal is not particularly limited as long as it dissolves in the liquid crystal. For example, the branch polymer can be synthesized using a compound represented by the following formula (1), a compound represented by formula (2), a compound represented by formula (3), and a compound represented by formula (4).

[0036] (In formula (1), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, X represents a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, or thioether bond, R １ represents an alkyl group having 1 to 20 carbon atoms, into which a bonding group may be inserted, and n is an integer of 1 to 2. When n is 2, two X and R １ may be the same or different.) Examples of the linking group in the alkyl group having 1 to 20 carbon atoms into which a linking group may be inserted include an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, a thioether bond, -Si(R １１ ) (R １２ )-(R １１ and R １２ each independently represents an alkyl group bonded to Si.), —Si(R １３ ) (R １４ )-O-(R １３ and R １４ Each of these represents an alkyl group that is independently bonded to Si. ), -N (R １５ )-(R １５ R represents a hydrogen atom or alkyl group bonded to N. １１ ~R １５ Examples of alkyl groups in this context include alkyl groups having 1 to 6 carbon atoms.

[0037] (In formula (2), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, S represents a single bond or a saturated hydrocarbon group of 1 to 6 carbon atoms which may have a bonding group inserted therein, T represents an organic group represented by the following formula (2-T), and n is an integer of 1 to 2. When n is 2, the two Ts may be the same or different. However, when n is 2, S represents a saturated hydrocarbon group of 1 to 6 carbon atoms which may have a bonding group inserted therein.)

[0038] (In formula (2-T), * indicates a bonding site. X is a single bond, ether bond, ester bond, amide bond, urethane bond, urea bond, thioether bond, -Si(R) １ ) (R ２ )-(R １ and R２ each independently represents an alkyl group bonded to Si.), —Si(R ３ ) (R ４ )-O-(R ３ and R ４ each independently represents an alkyl group bonded to Si. ５ )-(R ５ represents a hydrogen atom or an alkyl group bonded to N; and Cy represents a non-aromatic cyclic group having 6 to 20 members.

[0039] The saturated hydrocarbon group for S in formula (2) refers to an (n+1)-valent group formed by removing (n+1) hydrogen atoms from a saturated hydrocarbon (n is the same integer as n in formula (2)). When n is 1, the saturated hydrocarbon group is an alkylene group. For S in formula (2), the saturated hydrocarbon group having 1 to 6 carbon atoms and having a linking group inserted therein means an (n+1)-valent group in which a linking group is inserted between carbon atoms within a saturated hydrocarbon group having 2 to 6 carbon atoms, or a divalent group in which a linking group is inserted between a saturated hydrocarbon group having 1 to 6 carbon atoms and an atom (for example, a carbon atom) bonding thereto. Examples of the linking group for S in formula (2) include a carbon-carbon unsaturated bond, an ether bond (—O—), an ester bond (—COO— or —OCO—), and an amide bond (—CONH— or —NHCO—). Examples of carbon-carbon unsaturated bonds include carbon-carbon double bonds, but it is preferable that the saturated hydrocarbon group having 1 to 6 carbon atoms into which a carbon-carbon double bond has been inserted has the carbon-carbon double bond internally rather than at its terminal. When n is 1, examples of the alkylene group having 1 to 6 carbon atoms into which a bonding group may be inserted include alkylene groups having 1 to 6 carbon atoms and oxyalkylene groups having 1 to 6 carbon atoms. The alkylene group having 1 to 6 carbon atoms may be a linear alkylene group, a branched alkylene group, or a cyclic alkylene group.

[0040] -Si(R) in X in equation (2-T) １ ) (R ２ )-R １ and R ２are each independently an alkyl group bonded to Si, for example, an alkyl group having 1 to 6 carbon atoms. ３ ) (R ４ )-O-'s R ３ and R ４ are each independently an alkyl group bonded to Si, for example, an alkyl group having 1 to 6 carbon atoms. ５ )-R ５ is a hydrogen atom or an alkyl group bonded to N. The alkyl group is, for example, an alkyl group having 1 to 6 carbon atoms.

[0041] In formula (2-T), Cy represents a 6- to 20-membered non-aromatic cyclic group, preferably an 8- to 18-membered non-aromatic cyclic group. Cy may also represent a 12- to 20-membered non-aromatic cyclic group. In formula (2-T), X is bonded to an atom constituting the ring in Cy. Examples of atoms constituting the ring in the non-aromatic cyclic group include carbon atoms, oxygen atoms, nitrogen atoms, and silicon atoms. The bond between atoms constituting the ring may be a single bond, a double bond, or a triple bond, with a single bond being preferred. Examples of rings in non-aromatic cyclic groups include cyclic alkanes, cyclic ethers, and cyclic siloxanes. Examples of cyclic ethers include crown ethers. For example, in 12-crown-4, the atoms constituting the ring are carbon atoms and oxygen atoms, and the ring has 12 members. The ring may be monocyclic or polycyclic. The number of rings in a polycyclic ring may be, for example, 2 to 4. In a polycyclic ring, the rings may be bonded to one another in the following three ways: - Sharing of one atom: For example, a spirocyclic compound - Sharing of two atoms: When two rings share two atoms, as in decalin - Bridged structure: When two rings are considered to share three or more atoms, as in norbornane In the case of a polycyclic ring, the number of atoms constituting the ring is used to indicate the number of ring members. For example, norbornane is a seven-membered ring. Instead of hydrogen atoms, halogen atoms or alkyl groups having 1 to 6 carbon atoms may be bonded to the atoms constituting the ring. Examples of halogen atoms include fluorine atoms and chlorine atoms.

[0042] (In formula (3), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, R １ The 'X' represents an aliphatic hydrocarbon group having a linear or branched structure with 1 to 10 carbon atoms, and each of the three 'X's independently represents a hydrogen atom or the following formula (3-X). However, at least one of the three 'X's represents the formula (3-X).

[0043] (In formula (3-X), Y represents a single bond, -O-, -S-, or -N(R)- (where R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms bonded to N), and * indicates a bonding site. ２ , R ３ , and R ４ each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have a substituent.

[0044] R in equation (3) １ The aliphatic hydrocarbon group in this product has 1 to 10 carbon atoms, and may have 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0045] R in formula (3-X) ２ , R ３ , and R ４ The C1-C6 alkyl group in this expression may, for example, be a C1-C5 alkyl group or a C1-C4 alkyl group. These alkyl groups may have a linear or branched structure.

[0046] R in formula (3-X) ２ , R ３ , and R ４ The aromatic hydrocarbon group in the compound may be unsubstituted, or its hydrogen atoms may be substituted by substituents. Examples of substituents on the aromatic hydrocarbon group that may have substituents include halogen atoms, C1-C4 alkyl groups, C1-C4 alkoxy groups, C1-C4 halogenated alkyl groups, and C1-C4 halogenated alkoxy groups. The halogenation in halogenated alkyl groups and halogenated alkoxy groups may be total halogenation or partial halogenation. Examples of halogen atoms include fluorine atoms and chlorine atoms. Examples of aromatic hydrocarbon groups that may have substituents include phenyl groups and naphthyl groups. The number of substituents on the aromatic hydrocarbon group is not particularly limited.

[0047] In formula (3), there is one or more formulas (3-X), and there may be one, two, or three. In formula (3), the three Xs are independent of each other. Therefore, when there are two or more formulas (3-X) in formula (3), the two or more formulas (3-X) may have the same structure or different structures.

[0048] In formula (3-X), R ２ , R ３ , and R ４ At least one of R may be an aromatic hydrocarbon group which may have a substituent. ２ , R ３ , and R ４ may be an aromatic hydrocarbon group which may have a substituent, or R ２ , R ３ , and R ４ may be an aromatic hydrocarbon group which may have a substituent, and R ２ , R ３ , and R ４ The three groups may be aromatic hydrocarbon groups which may have a substituent.

[0049] (In formula (4), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ ~R ３ each independently represents a single bond or an alkylene group having 1 to 6 carbon atoms into which a bonding group may be inserted; Ar represents an aromatic hydrocarbon group which may have a substituent; X １ and X ２ each independently represents a hydrogen atom or an aromatic hydrocarbon group which may have a substituent, R １ X １ and R ２ X ２ and R １ X １ and R ２ X ２ and the carbon atom bonded to R may form a ring together. １ X １ , R ２ X ２ and R ３The total number of carbon atoms is 1 or more.

[0050] R in formula (4) １ ~R ３ In the above, an alkylene group having 1 to 6 carbon atoms and a linking group inserted therein refers to a divalent group in which a linking group is inserted between carbon atoms within an alkylene group having 1 to 6 carbon atoms, or a divalent group in which a linking group is inserted between an alkylene group having 1 to 6 carbon atoms and the carbon atom bonded thereto. Examples of the linking group include a carbon-carbon unsaturated bond, an ether bond (-O-), an ester bond (-COO- or -OCO-), and an amide bond (-CONH- or -NHCO-). Examples of unsaturated bonds include a carbon-carbon double bond, but it is preferable that the alkylene group having 1 to 6 carbon atoms and a linking group has a carbon-carbon double bond internally rather than at its terminal. Examples of the alkylene group having 1 to 6 carbon atoms and optionally having a linking group inserted therein include an alkylene group having 1 to 6 carbon atoms and an oxyalkylene group having 1 to 6 carbon atoms. In the oxyalkylene group having 1 to 6 carbon atoms, the oxygen atoms are, for example, M and R in formula (4). １ , R ２ , and R ３ It bonds with the carbon atom that is bonded to it. The alkylene group having 1 to 6 carbon atoms may be a linear alkylene group, a branched alkylene group, or a cyclic alkylene group.

[0051] X in equation (4) １ and X ２ Examples of the aromatic hydrocarbon group which may have a substituent in the above formula include a phenyl group which may have a substituent and a naphthyl group which may have a substituent. Examples of the substituent include a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, and a halogenated alkoxy group having 1 to 4 carbon atoms. The halogenation in the halogenated alkyl group and the halogenated alkoxy group may be complete or partial. Examples of the halogen atom include a fluorine atom and a chlorine atom.

[0052] R in formula (4)１ Examples include single bonds and alkylene groups having 1 to 6 carbon atoms. More specifically, examples of alkylene groups having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. R in formula (4) ２ Examples include single bonds and alkylene groups having 1 to 6 carbon atoms. More specifically, examples of alkylene groups having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. R in formula (4) ３ Examples include single bonds and alkylene groups having 1 to 6 carbon atoms. More specifically, examples of alkylene groups having 1 to 6 carbon atoms include linear alkylene groups having 1 to 6 carbon atoms. X in formula (4) １ Examples of X in formula (4) include a hydrogen atom and a phenyl group. ２ Examples of Ar include a hydrogen atom and a phenyl group. Examples of Ar in formula (4) include a phenyl group.

[0053] R in formula (4) １ X １ , R ２ X ２ and R ３ The total number of carbon atoms in R is not particularly limited as long as it is 1 or more, but may be 2 or more. １ , R ２ , and R ３ The total number of carbon atoms in the formula (4) may be, for example, 18 or less, 15 or less, or 10 or less. １ and X ２ When is a hydrogen atom, R １ , R ２ , and R ３ The total number of carbon atoms in X in formula (4) is not particularly limited as long as it is 1 or more, but may be 2 or more. １ and X ２ In the case where at least one of the groups is an aromatic hydrocarbon group which may have a substituent, R １ , R ２ , and R ３ The total number of carbon atoms may be 0.

[0054] In formula (4), R１ X １ and R ２ X ２ and R １ X １ and R ２ X ２ and the carbon atom to which it is bonded, can be exemplified by a hydrocarbon ring having 3 to 13 carbon atoms, into which a bonding group may be inserted. The bonding group is as described above.

[0055] By using the structure of the above compound, it is easy to achieve high-speed response when the voltage is turned off, reduction in burn-in, high backlight transmittance in a low-temperature environment, and low-voltage driving.

[0056] The monomer used for synthesizing the branch polymer may be a single component or a combination of multiple monomers, and may also be used in combination with other radically polymerizable monomers described below.

[0057] In branch polymers, the structure excluding the terminal groups or side chain structures that react with the stem polymer may be a single polymer structure using only one monomer represented by formulas (1), (2), (3), and (4) above, or a copolymer structure combining multiple monomers. When combining multiple monomers, random copolymerization or block copolymerization may be used. When combining monomers represented by formulas (1), (2), (3), and (4) above, the ratio is not particularly limited regardless of the combination method. It is preferable to use these synthesis methods, combined monomers, and combination ratios within a range that yields the desired physical properties, labeling characteristics, electrical properties, etc.

[0058] The polymerizable group having a polymerizable unsaturated hydrocarbon group (for example, M in formulas (1) to (4)) used in the synthesis of the branch polymer preferably has the following structure: (In the formula, R １ , and R ２ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, and X, Y, and Z each independently represent an oxygen atom or a sulfur atom. １ and * ２ represents a binding site, * １ and *２ Either one of the groups may be replaced by a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms. n represents an integer of 1 to 5.

[0059] For example, the macromonomer (polymer (B1)) that is a raw material for forming the branch polymer of the graft copolymer of the present invention has a group L in its terminal or side-chain structure that can be covalently bonded to the stem polymer (polymer (A)). The graft copolymer can be synthesized by grafting the macromonomer (polymer (B1)) to the stem polymer via the group L. In other words, the polymer (B) constituting the graft copolymer is derived from polymer (B1) which has a group L in its terminal or side-chain structure that can be covalently bonded to polymer (A). For example, a graft copolymer can be obtained by bonding a polymer selected from polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea to a macromonomer (polymer (B1)) which has a group L in its terminal or side-chain structure via the group L.

[0060] Examples of group L include groups selected from hydroxyl groups, phenol groups, optionally protected amino groups, optionally protected aniline groups, optionally protected thiol groups, optionally protected thiophenol groups, epoxy groups, oxetane groups, allyl groups, vinyl groups, methacrylic groups, acrylic groups, oxazoline groups, optionally protected isocyanate groups, and aldehyde groups.

[0061] Here, the protecting group in the protected amino (protected aniline) group, the protecting group in the protected thiol (protected thiophenol) group, and the protecting group in the protected isocyanate group refer to groups that are eliminated by heating to generate an amino (aniline) group, a thiol (thiophenol) group, and an isocyanate group, respectively. Examples of the protecting group in the protected amino (protected aniline) group include a tert-butoxycarbonyl group, a benzyloxycarbonyl group, a 9-fluorenylmethyloxycarbonyl group, an allyloxycarbonyl group, a phthaloyl group, a nitrobenzenesulfonyl group, a (2-trimethylsilyl)-ethanesulfonyl group, a 2,2,2-trichloroethoxycarbonyl group, and an azide group. Examples of the protecting group in the protected thiol (protected thiophenol) group include a tert-butoxycarbonyl group, a benzyloxycarbonyl group, a 9-fluorenylmethyloxycarbonyl group, an allyloxycarbonyl group, a phthaloyl group, a nitrobenzenesulfonyl group, a (2-trimethylsilyl)-ethanesulfonyl group, a 2,2,2-trichloroethoxycarbonyl group, an azide group, etc. Examples of the protecting group in the protected isocyanate group (blocked isocyanate group) include a tert-butyl group, a dimethylpyrazole group, a methyl ethyl ketone oxime group, a lactam group, etc.

[0062] Examples of the monomer that provides the group L include compounds represented by the following formula (5). (In formula (5), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, n is an integer of 1 to 2, and Z represents a group represented by the following formula (5-Z). When n is 2, two Zs may be the same or different.) (In formula (5-Z), L represents an amino group which may be protected, an aniline group which may be protected, a hydroxy group which may be protected, a phenol group which may be protected, a thiol group which may be protected, a thiophenol group which may be protected, a carboxy group which may be protected, a benzoic acid group which may be protected, an isocyanate group which may be protected, a cyclic ether group having 2 to 5 carbon atoms, a maleimide group, a carboxylic acid anhydride group, an N-hydroxysuccinimide ester group, an oxazoline group, a trialkoxysilyl group, a vinyl group which may be substituted with an alkyl group having 1 to 16 carbon atoms, an ethynyl group which may be substituted with an alkyl group having 1 to 16 carbon atoms, an allyl group, a styryl group, an α- represents a functional group selected from the group consisting of a hydroxyacetophenone group, an α-aminoalkylphenone group, an oxime ester group, and an acylphosphine oxide group. J represents a single bond or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. K and Q each independently represent a linking group selected from a single bond, an ether bond, an ester bond, an amide bond, a urea bond, a urethane bond, and a thioether bond. P represents a single bond or a phenylene group. R represents a single bond or an alkylene group having 1 to 16 carbon atoms. * represents a bonding site. m is an integer of 1 to 3. When m is 2 or 3, multiple K, P, Q, R, and L may be the same or different. However, when J is a single bond, m is 1.

[0063] Examples of the polymerizable group M in formula (5) include the same as the "polymerizable group having a polymerizable unsaturated hydrocarbon group used in the synthesis of the branch polymer" described above.

[0064] Specific examples of the -RL structure in formula (5-Z) are shown below, but the invention is not limited thereto. (X, Y, and Z each independently represent an oxygen atom or a sulfur atom. R １ , R ２ and R ３ R each independently represents an alkyl group having 1 to 18 carbon atoms. ４ represents a single bond or an alkylene group having 1 to 16 carbon atoms. ５ represents an alkylene group having 1 to 4 carbon atoms. * represents a bonding site, and n represents an integer of 0 to 5.

[0065] From the viewpoint of availability and weak anchoring characteristics, monomers that provide the group L used in the weak anchoring liquid crystal alignment agent of the present invention include monomers represented by the following compounds B-1 to B-12. (Boc represents a tert-butoxycarbonyl group.)

[0066] When a macromonomer contains a group L reactive with the trunk polymer in its side chain, the ratio of the monomer having the side chain structure reactive with the trunk polymer to the monomer represented by the above formulas (1), (2), (3), (4), and (5) that exhibits weak anchoring properties is important. This is due to the presence of multiple reactive sites on both the branch polymers and the trunk polymer that constitute the graft copolymer of the present invention. For example, if the macromonomer that constitutes the branch polymer contains more than necessary of the group L reactive with the trunk polymer, a three-dimensionally crosslinked polymer will be obtained, inducing gelation, while if the amount is less than necessary, the reaction will not proceed sufficiently and the desired effect will not be achieved. Therefore, if the group L reactive with the trunk polymer in the macromonomer is within the desired range, a multi-point reaction with the trunk polymer will not occur, and a uniform graft copolymer will be obtained. In the monomers constituting the branch polymer, the ratio (M1 / M2) of the monomer (M1) having a side chain structure that reacts with the trunk polymer to the monomer (M2) that is compatible with the liquid crystal and exhibits weak anchoring property is preferably 30 / 70 to 1 / 99 (mol / mol), more preferably 20 / 80 to 3 / 97 (mol / mol).

[0067] From the viewpoint of exhibiting better weak anchoring properties, the macromonomer is preferably a block copolymer or a gradient copolymer. The present applicant has found that even when a monomer compatible with liquid crystal and a monomer incompatible with liquid crystal are used in combination, the weak anchoring properties are not impaired by making it a block copolymer or a gradient copolymer. The applicant has found that a weak anchoring liquid crystal aligning agent containing a block copolymer composed of a block segment obtained by polymerizing a monomer compatible with liquid crystal represented by the above formulas (1), (2), (3), and (4) and a block segment obtained by polymerizing a monomer that is not compatible with liquid crystal or becomes incompatible with liquid crystal by baking exhibits good weak anchoring properties, and has filed a patent application (WO2022 / 260048. The contents of this application are incorporated herein by reference to the same extent as if expressly set forth in full). When the macromonomer of the present invention is a block copolymer or a gradient copolymer, the ratio (M1 / M2) of the monomer (M1) having a side chain structure that reacts with the backbone polymer to the monomer (M2) that is compatible with the liquid crystal and exhibits weak anchoring ability is not particularly limited, but is preferably 30 / 70 to 1 / 99 (mol / mol), and more preferably 20 / 80 to 3 / 97 (mol / mol).

[0068] In the graft copolymer used in the weak anchoring liquid crystal aligning agent of the present invention, the branch polymer plays a major role in the expression of weak anchoring properties. Because the physical properties of the weak anchoring film change depending on the molecular weight of the branch polymer, optimizing the molecular weight is important. From the viewpoint of forming a good weak anchoring film, the branch polymer preferably has a weight-average molecular weight of 1,000 to 100,000, more preferably 3,000 to 50,000, and the molecular weight distribution (PDI), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), is preferably 3.0 or less, more preferably 2.0 or less. When the graft copolymer is synthesized by the grafting-to method using a macromonomer, the molecular weight referred to here corresponds to the molecular weight of the macromonomer.

[0069] The macromonomer, which is the raw material for forming the branch polymer of the graft copolymer of the present invention, can be obtained, for example, by a combination of living polymerization, chain transfer polymerization, and polymer end-modification reaction. It has also been reported that continuous bulk polymerization at high temperatures of 200°C or higher can produce polymers having radically polymerizable unsaturated bonds at the end groups (Toagosei Research Annual Report, TREND 2002, No. 5). Living polymerization is a polymerization reaction that does not involve side reactions such as chain transfer reactions and termination reactions during the polymerization reaction, and can produce polymers with narrow molecular weight distributions and highly controlled structures. For example, a method can be used in which stable covalently bonded species called dormant species are introduced into the polymerization active site to suppress deactivation of the active site and prevent side reactions such as chain transfer reactions and termination reactions. Living polymerization can be performed using radicals, cations, or anions as active species, and it is important to select the appropriate method depending on the structure and properties of the monomer used. Although the polymerization method used to obtain the macromonomer serving as the raw material for the graft copolymer used in the weak anchoring liquid crystal alignment film of the present invention does not need to be particularly limited, cationic polymerization and anionic polymerization often use alkali metals, metal complexes, or halogen compounds to generate active species. Since the inclusion of metal residues or halogen compounds in liquid crystal displays can cause image sticking and display defects, radical polymerization that does not use metals or halogen compounds as much as possible is preferred. Examples of living radical polymerization include nitroxide-mediated radical polymerization (NMP) using a nitroxide as a dormant species, atom transfer radical polymerization (ATRP) using a metal complex, reversible addition-fragmentation chain transfer (RAFT) polymerization using a sulfur compound as a dormant, living radical polymerization (TERP) using an organotellurium compound, and reversible transfer catalyst polymerization (RTCP) using an alkyl iodide compound as a dormant species and a phosphorus compound, alcohol, or the like as a catalyst. Preferred polymerization methods include living radical polymerizations such as NMP, RTCP, and RAFT polymerization, with NMP or RAFT polymerization being particularly preferred.

[0070] When NMP is used, examples of the polymerization initiator include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, 1,1'-bis(t-butylperoxy)cyclohexane, and hydrogen peroxide. The proportion of the polymerization initiator used is typically 0.000001 to 0.1 molar parts, and preferably 0.00001 to 0.01 molar parts, per molar part of the monomer used. Examples of nitroxides include compounds represented by the following formulas (N-1) to (N-12). The proportion of the nitroxide used is typically 0.000001 to 0.1 molar parts, and preferably 0.00001 to 0.01 molar parts, per molar part of the monomer used. The reaction temperature in the polymerization is preferably 20 to 200°C, more preferably 40 to 150°C, and the reaction time is preferably 1 to 168 hours, more preferably 8 to 72 hours.

[0071]

[0072] When using RTCP, in addition to low-molecular-weight dormant species that contribute to the development of living properties, it is necessary to use an iodide catalyst or hydride catalyst and a polymerization initiator to promote the reaction. Examples of polymerization initiators that can be used include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, 1,1'-bis(tert-butylperoxy)cyclohexane, and hydrogen peroxide. The proportion of the polymerization initiator used is typically 0.000001 to 0.1 molar parts, preferably 0.00001 to 0.01 molar parts, per molar part of the monomer used. Examples of low-molecular-weight dormant species include compounds represented by the following formulas (Q-1) to (Q-3). The proportion of the low-molecular-weight dormant species used is usually 0.000001 to 0.1 molar parts, preferably 0.00001 to 0.01 molar parts, relative to 1 molar part of the monomer used. Examples of the iodide catalyst include compounds represented by the following formulas (P-1) to (P-4). The proportion of the iodide catalyst used is usually 0.000001 to 0.1 molar parts, preferably 0.00001 to 0.01 molar parts, relative to 1 molar part of the monomer used. Examples of the hydride catalyst include compounds represented by the following formulas (O-1) to (O-6). The proportion of the hydride catalyst used is 0.000001 to 0.1 molar parts, preferably 0.00001 to 0.01 molar parts, relative to 1 molar part of the monomer used. Generally, the reaction temperature in the polymerization is preferably 20 to 200° C., more preferably 40 to 150° C., and the reaction time is preferably 1 to 168 hours, more preferably 8 to 72 hours.

[0073]

[0074] When RAFT polymerization is used, examples of the polymerization initiator used include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, 1,1'-bis(t-butylperoxy)cyclohexane, and hydrogen peroxide. The proportion of the polymerization initiator used is typically 0.000001 to 0.1 molar parts, and preferably 0.00001 to 0.01 molar parts, per molar part of the monomer used. Preferred chain transfer agents (RAFT agents) include trithiocarbonates, dithiobenzoates, dithiocarbamates, and xanthates, and specific examples include compounds represented by the following formulas (R-1) to (R-24). The proportion of the chain transfer agent used is typically 0.000001 to 0.1 molar parts, and preferably 0.00001 to 0.01 molar parts, per molar part of the monomer used. The reaction temperature in the polymerization is preferably 20 to 200° C., more preferably 40 to 150° C., and the reaction time is preferably 1 to 168 hours, more preferably 8 to 72 hours.

[0075]

[0076] Living radical properties are manifested in RAFT polymerization because compounds capable of reversibly deactivating propagating radical species exist, and a rapid equilibrium exists between active and dormant chains, such that the majority of living chains are in the dormant form.

[0077] By using RAFT polymerization, it is possible to control the polymer end, the molecular weight, and the molecular weight distribution to a high degree.

[0078] To precisely synthesize functional polymers using RAFT polymerization, it is necessary to select an appropriate chain transfer agent taking into consideration the reactivity of the monomers.

[0079] In RAFT polymerization, the polymer terminals can be controlled by thermally or chemically modifying the RAFT terminals present at the growing terminals. Thermal modification can convert the terminals to unsaturated hydrocarbon groups by heating the polymer at a temperature above the thermal decomposition temperature of the RAFT agent used. Chemical modification can also convert the terminals to thiol bonds by contacting the polymer with a primary amine, secondary amine, or the like, which involves aminolysis. Furthermore, contacting the polymer with a new monomer and a radical generator can provide a new block segment at the terminal.

[0080] In RAFT polymerization, molecular weight control is possible using the following equation (eq1): Specifically, the number average molecular weight (Mn) changes linearly with the ratio of the molar concentration of the monomer to the molar concentration of the chain transfer agent, making it possible to control the molecular weight.

[0081] (In the above formula (eq1), Mn （ｔｈｅｏｒ） represents the molecular weight of the polymer, and [Monomer] ０ represents the molar concentration of the monomer, and [CTA] ０ represents the molar concentration of the chain transfer agent, M ｍｏｎｏｍｅｒ represents the molecular weight of the monomer, conv. represents the polymerization conversion rate, M ＣＴＡ represents the molecular weight of the chain transfer agent.)

[0082] Major methods for synthesizing the graft copolymer of the present invention include a grafting-to method in which a branch polymer is directly introduced into a trunk polymer, a grafting-from method in which a branch polymer is extended by polymerizing a monomer from a macroinitiator (a trunk polymer having a polymerization active site), and a grafting-through method in which a macromonomer (a polymer having a polymerizable functional group at one end) is polymerized, but any of these methods can be used, and therefore the synthesis method is not limited.

[0083] The method for producing the graft copolymer used in the present invention is not particularly limited, and a general-purpose method used industrially can be used. Specifically, the graft copolymer can be produced by radical polymerization, cationic polymerization, or anionic polymerization using the above-mentioned monomers. Among these, radical polymerization is particularly preferred from the viewpoint of ease of reaction control, etc.

[0084] As the polymerization initiator for radical polymerization, known compounds such as radical polymerization initiators (radical thermal polymerization initiators, radical photopolymerization initiators) and reversible addition-fragmentation chain transfer (RAFT) polymerization reagents can be used.

[0085] The radical thermal polymerization initiator is a compound that generates radicals when heated to a temperature equal to or higher than its decomposition temperature. Examples of such radical thermal polymerization initiators include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), acyl peroxides (acetyl peroxide, benzoyl peroxide, etc.), hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyketals (dibutylperoxycyclohexane, etc.), alkyl peresters (peroxyneodecanoic acid-tert-butyl ester, peroxypivalic acid-tert-butyl ester, peroxy-2-ethylcyclohexanoic acid-tert-amyl ester, etc.), persulfates (potassium persulfate, sodium persulfate, ammonium persulfate, etc.), and azo compounds (azobisisobutyronitrile, 2,2′-di(2-hydroxyethyl)azobisisobutyronitrile, etc.). The radical thermal polymerization initiators may be used alone or in combination of two or more.

[0086] The radical photopolymerization initiator is not particularly limited as long as it is a compound that initiates radical polymerization by irradiation with light. Examples of such radical photopolymerization initiators include benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexylphenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, α, α -diethoxyacetophenone, α,α-dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-di(tert-butylperoxycarbonyl)benzophenone, 3,4,4'-tri(tert-butylperoxycarbonyl)benzophenone, benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxystyryl)- 4,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4'-methoxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-mercaptobenzothiazole, 3,3'-Carbonylbis(7-diethylaminocoumarin), 2-(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 3-(2-methyl-2-dimethylaminopropionyl)carbazole, 3,6-bis(2-methyl-2-morpholinopropionyl)-9-n-dodecylcarbazole, 1-hydroxycyclohexyl phenyl ketone, bis(5-2,4-cyclo pentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetrakis(tert-hexylperoxycarbonyl)benzophenone, 3,3'-bis(methoxycarbonyl)-4,4'-bis(tert-butylperoxycarbonyl)benzophenone, 3,4'-bis( Examples of the radical photopolymerization initiator include 4,4'-bis(methoxycarbonyl)-4,3'-bis(tert-butylperoxycarbonyl)benzophenone, 4,4'-bis(methoxycarbonyl)-3,3'-bis(tert-butylperoxycarbonyl)benzophenone, 2-(3-methyl-3H-benzothiazol-2-ylidene)-1-naphthalen-2-yl-ethanone, and 2-(3-methyl-1,3-benzothiazol-2(3H)-ylidene)-1-(2-benzoyl)ethanone. The radical photopolymerization initiator may be used alone or in combination of two or more.

[0087] The radical polymerization method is not particularly limited, and may be an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, a bulk polymerization method, a solution polymerization method, etc. The organic solvent used in the radical polymerization reaction is not particularly limited as long as it dissolves the produced polymer. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoramide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), propylene glycol, propylene glycol monoacetate, propylene glycol monobutyl ether (butyl cellosolve), propylene glycol monoisopropyl ether ... monomethyl ether, propylene glycol mono-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,Examples of suitable organic solvents include 4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide. These organic solvents may be used alone or in combination of two or more.

[0088] Furthermore, even if the solvent does not dissolve the polymer produced, it may be mixed with the organic solvent described above to the extent that the polymer does not precipitate. Since oxygen in the organic solvent inhibits the polymerization reaction during radical polymerization, it is preferable to use an organic solvent that has been degassed to the greatest extent possible. When the graft copolymer obtained by the above polymerization is dissolved in the reaction solution, the reaction solution may be used directly to prepare the liquid crystal aligning agent, or the graft copolymer contained in the reaction solution may be isolated and then used to prepare the liquid crystal aligning agent. The polymerization temperature during radical polymerization can be selected from any temperature between 30 and 150°C, but is preferably in the range of 50 to 100°C. The reaction can be carried out at any concentration; however, if the concentration is too low, it becomes difficult to obtain a high-molecular-weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high, making uniform stirring difficult. Therefore, the monomer concentration is preferably 1 to 80% by mass, more preferably 10 to 60% by mass. The reaction can be carried out at a high concentration initially, followed by the addition of organic solvent.

[0089] In the above-mentioned radical polymerization reaction, if the ratio of the radical polymerization initiator to the monomer is high, the molecular weight of the obtained polymer will be small, and if the ratio is low, the molecular weight of the obtained polymer will be large, so the ratio of the radical initiator to the monomer to be polymerized is preferably 0.1 to 10 mol %. Furthermore, various monomer components, solvents, initiators, etc. can also be added during polymerization.

[0090] The polymer produced from the reaction solution obtained by the above reaction can be recovered by pouring the reaction solution into a poor solvent and precipitating it, but this reprecipitation treatment is not essential. Examples of poor solvents used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by pouring into a poor solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the impurities in the polymer can be reduced by repeating the procedure of redissolving the recovered polymer in an organic solvent and reprecipitating and recovering it 2 to 10 times. Examples of poor solvents used in this case include alcohols, ketones, and hydrocarbons. Using three or more poor solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0091] In consideration of the strength of the resulting coating film, the workability during coating film formation, and the uniformity of the coating film, the weight average molecular weight of the graft copolymer used in the present invention, as measured by Gel Permeation Chromatography (GPC), is preferably 2,000 to 5,000,000, and more preferably 5,000 to 2,000,000.

[0092] (Backbone Polymer) The backbone polymer is at least one polymer (polymer (A)) selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea. The backbone polymer is mainly responsible for stabilizing the membrane and enhancing its functionality, and contributes to improving coatability, solvent selectivity, mechanical strength, and adhesion to seals and substrates. In particular, by using a polymer selected from the above-mentioned polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea as the backbone polymer, it is possible to solve problems with process margins, including the baking method, baking temperature, and coating method, that may arise in conventional polymer alloy coating materials (see WO 2024 / 058164).

[0093] When a polyamic acid, polyimide, or polyamic acid ester is used as the trunk polymer, the polymer before being introduced as the trunk polymer into the graft copolymer contains a carboxy group formed by the reaction of a tetracarboxylic dianhydride with a diamine and a carboxylic acid (anhydride) or an amino group at the polymer chain end. Therefore, unless the imidization rate is 100%, all polyamic acids and polyimides correspond to polymer (A). However, specific examples include polymers composed of the following diamines and tetracarboxylic dianhydrides:

[0094] Examples of diamine components used in the synthesis of polyamic acid and polyimide include the following diamines: p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, and 4,4'-diaminobiphenyl. , 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'- Diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis(4-aminophenyl)silane, bis( 3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 2,2'-diaminobenzophenone, 2,3'-diaminobenzophenone, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene Phthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene , 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(methylene)]dianiline, 4,4'-[1,3-phenylenebis(methylene)]dianiline, 3,4'-[1,4-phenylenebis(methylene)]dianiline, 3,4'-[1,3-phenylenebis(methylene)]dianiline, 3,3'-[1,4-phenylenebis(methylene)]dianiline 1,4-phenylenebis[(4-aminophenyl)methanone], 1,4-phenylenebis[(3-aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3-phenylenebis[(3-aminophenyl)methanone], 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, N,N'-(1,4-phenylene)bis(4-aminobenzamide), N,N'-(1,3-phenylene)bis(4-aminobenzamide), N,N'-(1,4-phenylene)bis(3-aminobenzamide), N,N'-(1,3-phenylene)bis(3-aminobenzamide), N,N'-bis(4- N,N'-bis(3-aminophenyl)terephthalamide, N,N'-bis(4-aminophenyl)isophthalamide, N,N'-bis(3-aminophenyl)isophthalamide, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoro Propane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, trans-1,4-bis(4-aminophenyl)cyclohexane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4 -aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,Aromatic diamines such as 8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, and 1,12-bis(3-aminophenoxy)dodecane; alicyclic diamines such as bis(4-aminocyclohexyl)methane and bis(4-amino-3-methylcyclohexyl)methane; 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, and 1,7-diaminoheptane, Examples of the diamine include aliphatic diamines such as 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, and 1,12-diaminododecane; diamines having a urea structure such as 1,3-bis[2-(p-aminophenyl)ethyl]urea and 1,3-bis[2-(p-aminophenyl)ethyl]-1-tert-butoxycarbonylurea; diamines having a nitrogen-containing unsaturated heterocyclic structure such as N-p-aminophenyl-4-p-aminophenyl(tert-butoxycarbonyl)aminomethylpiperidine; and diamines having an N-Boc group (Boc represents a tert-butoxycarbonyl group) such as N-tert-butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine. The above diamines can be used alone or in combination of two or more.

[0095] The tetracarboxylic dianhydride to be reacted with the diamine component is not particularly limited. Specific examples include pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl)ether, 3,3',4,4'-benzophenonetetracarboxylic acid, and bis(3,4-dicarboxyphenyl)ether. bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyphenyl)diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenylsulfonetetracarboxylic acid carboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid, oxydiphthaltetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclo tetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid, bicyclo[4.3.0]nonane-2,4,7,9-tetracarboxylic acid, bicyclo[4.4.0]decane-2,4,7,9-tetracarboxylic acid, bicyclo[4.4.0]decane-2,4,8,10-tetracarboxylic acid, tricyclo[6.3.0.0<2,6>]undecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, bicyclo[2.2.2]oct-7-ene-2,3 ,5,6-tetracarboxylic acid, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo[6.2.1.1.0<2,7>]dodeca-4,5,9,10-tetracarboxylic acid, 3,5,6-tricarboxynorbornane-2,3,5,6-tetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and other tetracarboxylic acid dianhydrides. Of course, one type of tetracarboxylic acid dianhydride may be used alone, or two or more types may be used in combination.

[0096] In the synthesis of a polyamic acid ester polymer, the structure of the tetracarboxylic acid dialkyl ester to be reacted with the diamine component is not particularly limited, but specific examples are given below. Specific examples of aliphatic tetracarboxylic acid diesters 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, and 3,4-dicarboxy-1-cyclohexylsuccinic acid dialkyl ester. ter, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid dialkyl ester, 1,2,3,4-butane tetracarboxylic acid dialkyl ester, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid dialkyl ester, 3,3',4,4'-dicyclohexyl tetracarboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentyl acetic 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-dialkyl ester, 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-dialkyl ester, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarbon dialkyl ester, and the like.Examples of aromatic tetracarboxylic acid dialkyl esters include pyromellitic acid dialkyl esters, 3,3',4,4'-biphenyltetracarboxylic acid dialkyl esters, 2,2',3,3'-biphenyltetracarboxylic acid dialkyl esters, 2,3,3',4'-biphenyltetracarboxylic acid dialkyl esters, 3,3',4,4'-benzophenonetetracarboxylic acid dialkyl esters, 2,3,3',4'-benzophenonetetracarboxylic acid dialkyl esters, bis(3,4-dicarboxyphenyl)ether dialkyl esters, bis(3,4-dicarboxyphenyl)sulfone dialkyl esters, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl esters, and 2,3,6,7-naphthalenetetracarboxylic acid dialkyl esters.

[0097] When the polymer used as the trunk polymer is a polyurea, the polymer before being introduced into the graft copolymer as the trunk polymer has an isocyanate group or an amino group at the polymer chain terminal group, so all polyureas fall under the category of polymer (A). A specific example would be a polymer composed of a diamine component and a diisocyanate. Examples of diamine components used in the synthesis of polyurea include the diamine components used in the synthesis of the aforementioned polyamic acid and polyimide. The diisocyanate to be reacted with the diamine component in the synthesis of polyurea is not particularly limited, and can be selected depending on availability, etc. The specific structure of diisocyanate is shown below.

[0098] In the formula R １ , and R ２ represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0099] Aliphatic diisocyanates represented by formulas (K-1) to (K-5) have the advantage of being inferior in reactivity but improving solvent solubility, while aromatic diisocyanates represented by formulas (K-6) to (K-17) are highly reactive and have the effect of improving heat resistance, but have the disadvantage of reducing solvent solubility. In terms of versatility and properties, formulas (K-1), (K-8), (K-9), (K-10), and (K-11) are preferred, while formula (K-14) is preferred from the viewpoint of electrical properties, and formula (K-15) is preferred from the viewpoint of liquid crystal alignment. Two or more diisocyanates can be used in combination, and it is preferable to apply various types depending on the properties desired.

[0100] Furthermore, a portion of the diisocyanate may be replaced with the tetracarboxylic dianhydride described above, and the polyurea may be used in the form of a copolymer of polyamic acid and polyurea, or may be used in the form of a copolymer of polyimide and polyurea obtained by chemical imidization. In this specification, such copolymers are also included in the scope of polyurea.

[0101] When the polymer used as the trunk polymer is a polyamide, the polymer before being introduced into the graft copolymer as the trunk polymer has a carboxy group or an amino group at the polymer chain end group, and therefore all polyamides fall under the category of polymer (A), but specific examples are as follows: Aliphatic dicarboxylic acids used in the synthesis of polyamides include dicarboxylic acids such as malonic acid, oxalic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, muconic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, and suberic acid. Examples of alicyclic dicarboxylic acids include 1,1-cyclopropanedicarboxylic acid, 1,2-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 3,4-diphenyl-1,2-cyclobutanedicarboxylic acid, 2,4-diphenyl-1,3-cyclobutanedicarboxylic acid, 1-cyclobutene-1,2-dicarboxylic acid, 1-cyclobutene-3,4-dicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexane ...3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, Examples of the dicarboxylic acid include cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-(2-norbornene)dicarboxylic acid, norbornene-2,3-dicarboxylic acid, bicyclo[2.2.2]octane-1,4-dicarboxylic acid, bicyclo[2.2.2]octane-2,3-dicarboxylic acid, 2,5-dioxo-1,4-bicyclo[2.2.2]octanedicarboxylic acid, 1,3-adamantanedicarboxylic acid, 4,8-dioxo-1,3-adamantanedicarboxylic acid, 2,6-spiro[3.3]heptanedicarboxylic acid, 1,3-adamantanediacetic acid, and camphoric acid.Examples of aromatic dicarboxylic acids include o-phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-tert-butylisophthalic acid, 5-aminoisophthalic acid, 5-hydroxyisophthalic acid, 2,5-dimethylterephthalic acid, tetramethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-anthracenedicarboxylic acid, 1,4-anthraquinonedicarboxylic acid, 2,5-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,5-biphenylenedicarboxylic acid, 4,4"-terphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenyl Hexafluoropropanedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-bibenzyldicarboxylic acid, 4,4'-stilbene dicarboxylic acid, 4,4'-transicarboxylic acid, 4,4'-carbonyldibenzoic acid, 4,4'-sulfonyldibenzoic acid, 4,4'-dithiodibenzoic acid, p-phenylenediacetic acid, 3,3'-p-phenylenedipropionic acid, 4-carboxycinnamic acid, p- Examples of dicarboxylic acids include phenylenediacrylic acid, 3,3'-[4,4'-(methylenedi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dibutyric acid, (isopropylidenedi-p-phenylenedioxy)dibutyric acid, and bis(p-carboxyphenyl)dimethylsilane. Examples of dicarboxylic acids containing a heterocycle include 1,5-(9-oxofluorene)dicarboxylic acid, 3,4-furandicarboxylic acid, 4,5-thiazoledicarboxylic acid, 2-phenyl-4,5-thiazoledicarboxylic acid, 1,2,5-thiadiazole-3,4-dicarboxylic acid, 1,2,5-oxadiazole-3,4-dicarboxylic acid, 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, and 3,5-pyridinedicarboxylic acid.

[0102] The various dicarboxylic acids mentioned above may have an acid dihalide or anhydride structure. These dicarboxylic acids are preferably capable of producing polyamides with a linear structure, in order to maintain the alignment of liquid crystal molecules. Among these, terephthalic acid, isoterephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 2,2-bis(phenyl)propanedicarboxylic acid, 4,4-terphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,5-pyridinedicarboxylic acid, or acid dihalides thereof are preferably used. Some of these compounds have isomers, and mixtures containing these isomers may be used. Two or more compounds may also be used in combination. The dicarboxylic acids used in the present invention are not limited to the above-mentioned exemplary compounds.

[0103] A known synthesis method can be used to obtain polyamic acid, polyamic acid ester, polyurea, or polyamide by reacting a raw material diamine (also referred to as a "diamine component") with a raw material tetracarboxylic dianhydride (also referred to as a "tetracarboxylic dianhydride component"), a tetracarboxylic acid diester, a diisocyanate, and a dicarboxylic acid. Generally, this method involves reacting a diamine component with one or more components selected from a tetracarboxylic dianhydride component, a tetracarboxylic acid diester, a diisocyanate, and a dicarboxylic acid in an organic solvent.

[0104] Even if the monomer does not have a group reactive with the branch polymer in advance, it is possible to give the group reactive with the branch polymer in a polymer reaction after polymerization.

[0105] An example of the graft copolymer of the present invention has a branch polymer that is compatible with liquid crystal and a trunk polymer selected from polymers incompatible with liquid crystal, selected from polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, which are grafted by a synthesis method (grafting-to method) through a polymer reaction from two or more pre-synthesized polymers, thereby achieving improved coatability, solvent selectivity, mechanical strength, adhesion to seals and substrates, and process margins.

[0106] To achieve a balance between the coatability, solvent selectivity, mechanical strength, adhesion to seals and substrates, process margin, and weak anchoring properties of the weak anchoring liquid crystal alignment film, the ratio of branch polymer to trunk polymer introduced is also an important factor. For example, branch polymers play an important role in achieving weak anchoring properties, and a high ratio of branch polymer introduced can impair film strength and inhibit thermal curing, etc., so it is necessary to consider an appropriate amount of branch polymer introduced. On the other hand, the amount and molecular weight of the trunk polymer introduced do not affect (are small) the weak anchoring properties, so to achieve a balance between the above-mentioned properties, it is preferable to reduce the ratio of branch polymer to trunk polymer. The preferred ratio of branch polymer introduced (branch polymer / trunk polymer) is 1 / 99 to 50 / 50 (mass% / mass%), and more preferably 5 / 95 to 40 / 60 (mass% / mass%).

[0107] (Weak Anchoring Liquid Crystal Aligner) In the liquid crystal aligning agent containing the graft copolymer of the present invention, the component constituting the alignment film may be the graft copolymer alone or a composite material. The composite component other than the graft copolymer may be a monomer or a polymer. When a polymer is selected as the composite component, a mixture of multiple polymers can be used. Furthermore, the composite polymer may contain a polymer component such as polyamic acid, polyimide, polyamic acid ester, polyamide, polyester, polyurea, poly(meth)acrylate, or polyorganosiloxane, or may contain a silane coupling agent or other additives. From the viewpoint of improving electrical properties and reliability, it is preferable to use the graft copolymer in combination with a component other than the graft copolymer, and in particular, a combination of polyamic acid or polyimide is preferable. The composite ratio of the polymer to be composited with the graft copolymer is not particularly limited, but from the viewpoint of optical properties and processability, a preferred composite ratio (the proportion of the composite component relative to the total of the graft copolymer and the composite component) is 99% by mass or less, more preferably 70% by mass or less. The amount of additives added is also not particularly limited. When selecting a monomer as a composite component, a mixture of multiple monomers can be used. Furthermore, the composite monomer is preferably a thermally curable monomer such as a polyfunctional (meth)acrylate, a polyfunctional epoxide, or a polyfunctional ethylene, and a thermal acid generator, a thermal base generator, or a thermal radical generator may also be used in combination. The composite ratio of the monomer to be composited with the graft copolymer is not particularly limited, but from the viewpoint of optical properties and processability, a preferred composite ratio (the ratio of the composite component to the total of the graft copolymer and the composite component) is 99% by mass or less, and more preferably 70% by mass or less.

[0108] When polyamic acid, polyamic acid ester, polyimide, polyamide, or polyurea is used as the composite component, the polymers that can be used for the backbone polymer can be used.

[0109] One preferred embodiment of the poly(meth)acrylate as the composite component is a poly(meth)acrylate that is not the graft copolymer of the present invention described above, such as a polymer obtained by polymerizing industrially available radically polymerizable monomers using a general radical generator.

[0110] Specific examples of industrially available radically polymerizable monomers include unsaturated carboxylic acids, acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds.

[0111] Specific examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid.

[0112] Examples of acrylic acid ester compounds include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthrylmethyl 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, and 8-ethyl-8-tricyclodecyl acrylate. Acrylate compounds having a cyclic ether group, such as glycidyl acrylate, (3-methyl-3-oxetanyl)methyl acrylate, and (3-ethyl-3-oxetanyl)methyl acrylate, can also be used.

[0113] Examples of methacrylic acid ester compounds include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthrylmethyl 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-methyl-8-tricyclodecyl methacrylate, and 8-ethyl-8-tricyclodecyl methacrylate. Methacrylate compounds having a cyclic ether group, such as glycidyl methacrylate, (3-methyl-3-oxetanyl)methyl methacrylate, and (3-ethyl-3-oxetanyl)methyl methacrylate, can also be used.

[0114] Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

[0115] Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, and bromostyrene.

[0116] Examples of the maleimide compound include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

[0117] In addition to the above industrially available radically polymerizable monomers, side chain polymers using monomers having a liquid crystalline side chain structure (hereinafter referred to as liquid crystalline side chain monomers) and photosensitive monomers having a photosensitive group (hereinafter referred to as photoreactive side chain monomers) can also be used.

[0118] The liquid crystalline side chain monomer is a monomer that allows a polymer derived from the monomer to exhibit liquid crystallinity and that can form a mesogenic group at the side chain site. Specific examples of the liquid crystalline side chain monomer are preferably those having a structure that includes a polymerizable group composed of at least one radically polymerizable group selected from the group consisting of hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrenes, vinyls, maleimides, norbornenes, and a side chain having at least one of the "mesogenic groups of liquid crystalline side chains."

[0119] The liquid crystalline side chain monomer is preferably a monomer in which a liquid crystalline side chain selected from the following formulae (LS-1) to (LS-13) is bonded to a radically polymerizable polymerizable group. Examples of the radically polymerizable polymerizable group include the polymerizable groups having a polymerizable unsaturated hydrocarbon group exemplified in the description of the graft copolymer of the present invention. (In formulas (LS-1) to (LS-13), A １ and A ２ are each independently a single bond, —O—, or —CH ２ -, -C(=O)-O-, -OC(=O)-, -C(=O)NH-, -NHC(=O)-, -CH=CH-C(=O)O-, or -OC(=O)-CH=CH-; R １１ Ha-NO ２ , —CN, a halogen atom, a phenyl group, a naphthyl group, a biphenylyl group, a furanyl group, a monovalent nitrogen-containing heterocyclic group, a monovalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms; R １２ represents a group selected from the group consisting of a phenyl group, a naphthyl group, a biphenylyl group, a furanyl group, a monovalent nitrogen-containing heterocyclic group, a monovalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and a group obtained by combining any of these; R １１ and R １２ In the above, the hydrogen atoms bonded to these are -NO ２ , —CN, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; １３ is a hydrogen atom, -NO２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen atom, a phenyl group, a naphthyl group, a biphenylyl group, a furanyl group, a monovalent nitrogen-containing heterocyclic group, a monovalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms; E represents -C(=O)O- or -OC(=O)-; d represents an integer of 1 to 12; k1 to k5 are each independently an integer of 0 to 2, but the sum of k1 to k5 in each formula is 2 or more; k6 and k7 are each independently an integer of 0 to 2, but the sum of k6 and k7 in each formula is 1 or more; m1, m2, and m3 are each independently an integer of 1 to 3; n is 0 or 1; Z １ and Z ２ are each independently a single bond, —C(═O)—, or —CH ２ O—, —CH═N—, or —CF ２ -. Dashed lines represent bonds.)

[0120] In a photoreactive side chain monomer, a photosensitive side chain is attached to the main chain, and the photoreactive side chain monomer is a monomer having a side chain that can undergo a crosslinking reaction, an isomerization reaction, or a photo-induced Fries rearrangement in response to light. The structure of the photosensitive side chain is not particularly limited, but a structure that undergoes a crosslinking reaction or a photo-induced Fries rearrangement in response to light is desirable, and a structure that undergoes a crosslinking reaction is even more desirable. In this case, the realized alignment control ability can be stably maintained for a long period of time even when exposed to external stress such as heat. The structure of the photosensitive side chain acrylic polymer film that can exhibit liquid crystallinity is not particularly limited as long as it satisfies these properties, but it is preferable that the side chain structure has a rigid mesogen component.

[0121] The acrylic polymer may have a structure having, for example, a main chain and side chains bonded thereto, the side chains having a mesogen component such as a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenylbenzoate group, or an azobenzene group, and a photosensitive group bonded to the tip that undergoes a crosslinking reaction or an isomerization reaction in response to light; or a structure having a main chain and side chains bonded thereto, the side chains also serving as mesogen components and having phenylbenzoate groups that undergo a photo-induced Fries rearrangement reaction.

[0122] More specific examples of the structure of the photosensitive side-chain acrylic polymer that can exhibit liquid crystallinity within a predetermined temperature range preferably have a main chain composed of at least one radically polymerizable group selected from the group consisting of hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrenes, vinyls, maleimides, norbornenes, and the like, and a side chain composed of at least one of the following formulas (31) to (35): In the formula, Ar １ and Ar ２ each independently represents a divalent organic group obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring; one of q1 and q2 is 1 and the other is 0; Y １ -Y ２ represents CH═CH, CH═N, N═CH or C—C (wherein the carbon-carbon bond is a triple bond), and S １ and S ２ each independently represents a single bond, a linear or branched alkylene having 1 to 18 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a phenylene group, or a biphenylylene group; or represents one or more bonds selected from a single bond, an ether bond, an ester bond, an amide bond, a urea bond, a urethane bond, -NR- (R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms), and a carbonyl group, or a combination thereof; or a structure in which 2 to 10 moieties selected from a linear or branched alkylene having 1 to 18 carbon atoms, a cycloalkylene having 5 to 8 carbon atoms, phenylene, biphenylylene, or a combination thereof are bonded via the one or more bonds;１ and Ar ２ may have a structure in which a plurality of each of the groups are linked via the bond, R represents a hydrogen atom, a hydroxy group, a mercapto group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylamino group having 1 to 8 carbon atoms, or a dialkylamino group having 2 to 16 carbon atoms, Ar １ , Ar ２ , S １ and S ２ The benzene ring and / or naphthalene ring in the formula (I) may be substituted with one or more identical or different substituents selected from a halogen atom, a cyano group, a nitro group, a carboxy group, and an alkoxycarbonyl group having 2 to 11 carbon atoms. In this case, the alkyl group having 1 to 10 carbon atoms in the alkoxycarbonyl group having 2 to 11 carbon atoms may be linear, branched, or cyclic, or may have a structure combining these, and a hydrogen atom in the alkyl group having 1 to 10 carbon atoms may be substituted with a halogen atom.

[0123] The method for producing the polyacrylate is not particularly limited, and a general-purpose method used industrially can be used. Specifically, the polyacrylate can be produced by cationic polymerization, radical polymerization, or anionic polymerization using the vinyl group of a liquid crystalline side chain monomer or a photoreactive side chain monomer. Among these, radical polymerization is particularly preferred from the viewpoint of ease of reaction control.

[0124] As the polymerization initiator for radical polymerization, known radical polymerization initiators such as AIBN (azobisisobutyronitrile) and known compounds such as reversible addition-fragmentation chain transfer (RAFT) polymerization reagents can be used.

[0125] The radical polymerization method is not particularly limited, and may be an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, a bulk polymerization method, a solution polymerization method, or the like.

[0126] The organic solvent used in the polymerization reaction of a photosensitive side-chain acrylic polymer capable of exhibiting liquid crystallinity within a predetermined temperature range is not particularly limited as long as it dissolves the produced polymer. Specific examples are listed below. N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoramide, γ-butyrolactone, isopropyl alcohol, methoxymethyl pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, Propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,Examples of the organic solvent include 4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide. These organic solvents may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polymer to be produced, it may be mixed with the organic solvent as long as the polymer does not precipitate. In addition, since oxygen in the organic solvent inhibits the polymerization reaction in radical polymerization, it is preferable to use an organic solvent that has been degassed to the greatest extent possible.

[0127] The polymerization temperature during radical polymerization can be selected from any temperature between 30 and 150°C, but is preferably between 50 and 100°C. The reaction can be carried out at any concentration; however, if the concentration is too low, it becomes difficult to obtain a high-molecular-weight polymer, and if the concentration is too high, the reaction solution becomes too viscous, making uniform stirring difficult. Therefore, the monomer concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration initially, and then an organic solvent can be added. In the above-mentioned radical polymerization reaction, if the ratio of radical polymerization initiator to monomer is high, the molecular weight of the resulting polymer will be low; if the ratio is low, the molecular weight of the resulting polymer will be high. Therefore, the ratio of radical initiator to monomer to be polymerized is preferably 0.1 to 10 mol%. Various monomer components, solvents, initiators, etc. can also be added during polymerization.

[0128] To recover the resulting polymer from the reaction solution of a photosensitive side-chain polymer capable of exhibiting liquid crystallinity obtained by the above reaction, the reaction solution may be poured into a poor solvent to precipitate the polymer. Examples of poor solvents used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by pouring into the poor solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the precipitated polymer can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of poor solvents include alcohols, ketones, and hydrocarbons. Using three or more poor solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0129] The molecular weight of the photosensitive side-chain acrylic polymer capable of exhibiting liquid crystallinity within a predetermined temperature range is preferably 2,000 to 1,000,000, more preferably 5,000 to 100,000, in terms of weight average molecular weight measured by GPC, taking into consideration the strength of the resulting coating film, workability during coating film formation, and uniformity of the coating film.

[0130] Examples of organic solvents used in liquid crystal aligning agents include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoramide, γ-butyrolactone, isopropyl alcohol, and methoxymethyl Pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane,Examples of the organic solvent include n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and 2-ethyl-1-hexanol. These organic solvents may be used alone or in combination.

[0131] It is also preferable to use a solvent that improves the uniformity and smoothness of the coating film by mixing it with an organic solvent in which it has high solubility.

[0132] Examples of solvents that improve the uniformity and smoothness of the coating film include isopropyl alcohol, methoxymethyl pentanol, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexyl ethanol, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol,Examples of suitable solvents include 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, and 2-ethyl-1-hexanol. These solvents may be mixed in combination. When these solvents are used, their content is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, of the total solvent contained in the liquid crystal aligning agent.

[0133] The weak anchoring liquid crystal aligning agent of the present invention may contain components other than those described above. Examples thereof include a compound that improves the film thickness uniformity and surface smoothness when the composition contained in the weak anchoring liquid crystal aligning agent is applied, a compound that improves the adhesion between the composition contained in the weak anchoring liquid crystal aligning agent and the substrate, and a compound that further improves the film strength of the composition contained in the weak anchoring liquid crystal aligning agent.

[0134] Compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specific examples include Eftop EF301, EF303, and EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Megafac F171, F173, and R-30 (manufactured by DIC Corporation), Fluorad FC430 and FC431 (manufactured by 3M), and Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by AGC). When using these surfactants, the proportion used is preferably 0.01 to 2 parts by mass, and more preferably 0.01 to 1 part by mass, per 100 parts by mass of the total amount of polymers contained in the composition contained in the weak anchoring liquid crystal aligning agent.

[0135] Specific examples of compounds contained in the weak anchoring liquid crystal aligning agent that improve the adhesion between the composition 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-ethoxycarbonyl-3-aminopropyltriethoxysilane silane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N- Phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, 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, glycol Examples of suitable glycidyl ethers include serine diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 3-(N-allyl-N-glycidyl)aminopropyltrimethoxysilane, and 3-(N,N-diglycidyl)aminopropyltrimethoxysilane.

[0136] Furthermore, in order to further increase the film strength of the weak anchoring liquid crystal alignment film, phenolic compounds such as 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane and tetra(methoxymethyl)bisphenol may be added. When using these compounds, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the total amount of polymers contained in the weak anchoring liquid crystal alignment agent. Furthermore, in addition to the above, a dielectric or conductive substance may be added to the composition contained in the weak anchoring liquid crystal alignment agent in order to change the electrical properties, such as the dielectric constant and conductivity, of the weak anchoring liquid crystal alignment film, as long as the effects of the present invention are not impaired.

[0137] (Strong anchoring horizontal alignment film) A strong anchoring horizontal alignment film must be provided on the substrate opposite to the substrate provided with a weak anchoring liquid crystal alignment film. The strong anchoring horizontal alignment film described here is a liquid crystal alignment film that can align liquid crystals uniformly in the horizontal direction and has a sufficiently strong force to maintain the aligned liquid crystals, i.e., interfacial anchoring energy.

[0138] A strong anchoring horizontal alignment film can be obtained by uniaxially aligning the above-described polyamic acid, polyimide, polyamic acid ester, polyamide, polyester, polyacrylate, etc., by rubbing treatment, photoalignment treatment, etc. A strong anchoring horizontal alignment film can be obtained by combining the above-described monomers.

[0139] (Weak anchoring liquid crystal alignment film and strong anchoring horizontal alignment film) The weak anchoring liquid crystal alignment film of the present invention can be obtained by using the weak anchoring liquid crystal alignment agent described above. For example, the weak anchoring liquid crystal alignment agent used in the present invention can be applied to a substrate, followed by drying and baking to obtain a cured film, which can be used as is as a weak anchoring liquid crystal alignment film. In addition, this cured film can be subjected to alignment treatment by rubbing, irradiation with polarized light or light of a specific wavelength, or treatment with an ion beam, and it is also possible to irradiate the liquid crystal display element with UV light after filling with liquid crystal.

[0140] Similarly, a strong anchoring horizontal alignment film can be obtained by applying a strong anchoring liquid crystal alignment agent to a substrate, followed by drying and baking to obtain a cured film, and then performing an alignment treatment on the cured film.

[0141] In the present invention, the first substrate may be a substrate having a comb-teeth electrode, and the second substrate may be a counter substrate. Also, in the present invention, the second substrate may be a substrate having a comb-teeth electrode, and the first substrate may be a counter substrate. The substrates on which each liquid crystal alignment film is applied are not particularly limited as long as they are highly transparent, but substrates on which transparent electrodes for driving liquid crystals are formed are preferred.

[0142] Specific examples include substrates on which transparent electrodes are formed, such as glass plates, and plastic plates such as polycarbonate, poly(meth)acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth)acrylonitrile, triacetyl cellulose, diacetyl cellulose, and acetate butyrate cellulose. Substrates that can be used in IPS-mode liquid crystal display elements include electrode patterns such as standard IPS comb electrodes and PSA (Polymer-Stabilized Alignment) fishbone electrodes, and protrusion patterns such as MVA (Multi-domain Vertical Alignment).

[0143] Furthermore, in a highly functional element such as a TFT (Thin-Film-Transistor) type element, an element such as a transistor is formed between an electrode for driving the liquid crystal and a substrate.

[0144] When a transmissive liquid crystal display element is intended, the above-mentioned substrates are generally used. However, when a reflective liquid crystal display element is intended, an opaque substrate such as a silicon wafer can be used for only one of the substrates. In this case, a light-reflecting material such as aluminum can also be used for the electrode formed on the substrate. Methods for applying the weak anchoring liquid crystal alignment agent include spin coating, printing, inkjet printing, spraying, and roll coating. However, transfer printing is widely used industrially from the standpoint of productivity and is also preferably used in the present invention.

[0145] A drying step after application of the liquid crystal aligning agent is not necessarily required, but it is preferable to include a drying step when the time from application to baking is not consistent for each substrate, or when baking is not performed immediately after application. This drying step is sufficient as long as the solvent is removed to an extent that the coating film shape does not deform during transport of the substrate, and the drying method is not particularly limited. Preferred conditions for the drying step include drying on a hot plate at a temperature of 40 to 150°C, more preferably 60 to 100°C, for 0.5 to 30 minutes, more preferably 1 to 5 minutes. When the block segment that is incompatible with the liquid crystal is composed of a thermosetting compound, the baking step is preferably performed at a temperature above the curing temperature and below the thermal decomposition temperature of the polymer. Preferred conditions for the baking step include baking on a hot plate or heat circulation oven at a temperature of 80 to 250°C, more preferably 100 to 230°C, for 1 to 120 minutes, more preferably 5 to 30 minutes.

[0146] The thickness of the cured film can be selected as needed, but is preferably 5 nm or more, more preferably 10 nm or more, since this improves the reliability of the liquid crystal display element. Also, the thickness of the cured film is preferably 300 nm or less, more preferably 150 nm or less, since this prevents the power consumption of the liquid crystal display element from becoming extremely large.

[0147] In this way, a first substrate having a weakly anchoring liquid crystal alignment film and a second substrate having a strongly anchoring horizontal alignment film can be obtained. Methods for performing uniaxial alignment treatment include photo-alignment, oblique evaporation, rubbing, and uniaxial alignment treatment using a magnetic field.

[0148] When performing alignment treatment by unidirectional rubbing, for example, a rubbing roller wrapped with a rubbing cloth is rotated while the substrate is moved so that the rubbing cloth comes into contact with the film. When using a photoalignment method, alignment treatment can be performed by irradiating the entire film with polarized UV of a specific wavelength and heating it as necessary. In the case of the first substrate of the present invention on which comb-tooth electrodes are formed, the direction is selected depending on the electrical properties of the liquid crystal, but when using a liquid crystal with positive dielectric anisotropy, it is preferable that the rubbing direction be approximately the same as the direction in which the comb-tooth electrodes extend.

[0149] [Liquid Crystal Cell] The liquid crystal cell of the present invention can be obtained by arranging a substrate (e.g., a first substrate) having a weakly anchoring liquid crystal alignment film obtained using the liquid crystal aligning agent of the present invention by the above-described method and a substrate (e.g., a second substrate) having a known strongly anchoring liquid crystal alignment film so that the weakly anchoring liquid crystal alignment film faces the strongly anchoring liquid crystal alignment film, sandwiching a spacer between them, fixing them with a sealant, and injecting and sealing the liquid crystal. The size of the spacer used here is typically 1 to 30 μm, but preferably 2 to 10 μm. Furthermore, by arranging the rubbing directions of the first substrate and the second substrate parallel to each other, the cell can be used in an IPS mode or FFS mode. By arranging the rubbing directions perpendicular to each other, the cell can be used in a TN mode. An IPS substrate, which is a comb-shaped electrode substrate used in an IPS mode, comprises a substrate, a plurality of linear electrodes formed on the substrate and arranged in a comb-like pattern, and a liquid crystal alignment film formed on the substrate so as to cover the linear electrodes. The FFS substrate, which is a comb-tooth electrode substrate used in the FFS method, has a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-tooth shape, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0150] (Liquid Crystal Display Element) A liquid crystal display element has, for example, a first substrate, a second substrate disposed opposite the first substrate, and liquid crystal filled between the first and second substrates. The liquid crystal display element is fabricated using a first or second substrate provided with a weakly anchoring liquid crystal alignment film formed by applying the weakly anchoring liquid crystal aligning agent of the present invention, and a second or first substrate provided with a strongly anchoring horizontal alignment film. The liquid crystal display element can be made into a reflective liquid crystal display element by, for example, providing a liquid crystal cell with a reflective electrode, a transparent electrode, a λ / 4 plate, a polarizing film, a color filter layer, and the like, as needed, according to conventional methods. Furthermore, the liquid crystal display element can be made into a transmissive liquid crystal display element by providing a backlight, a polarizing plate, a λ / 4 plate, a transparent electrode, a polarizing film, a color filter layer, and the like, as needed, according to conventional methods.

[0151] FIG. 1 is a schematic cross-sectional view showing an example of an in-plane switching liquid crystal display element of the present invention, which is an example of an IPS-mode liquid crystal display element. In the in-plane switching liquid crystal display element 1 shown in FIG. 1, liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes a base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-like pattern, and a liquid crystal alignment film 2c formed on the base material 2a to cover the linear electrodes 2b. The counter substrate 4 includes a base material 4b and a weak anchoring liquid crystal alignment film or a strong anchoring horizontal alignment film (liquid crystal alignment film 4a) formed on the base material 4b. The liquid crystal alignment film 2c is, for example, the weak anchoring liquid crystal alignment film or the strong anchoring horizontal alignment film of the present invention. The liquid crystal alignment films on the opposing substrates are each fabricated by combining a strong anchoring horizontal alignment film and a weak anchoring liquid crystal alignment film. In this IPS LCD element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as indicated by electric force lines L.

[0152] FIG. 2 is a schematic cross-sectional view showing another example of an in-plane switching liquid crystal display element of the present invention, which is an example of an FFS-mode liquid crystal display element. In the in-plane switching liquid crystal display element 1 shown in FIG. 2, liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes a base material 2d, a surface electrode 2e formed on the base material 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-like pattern, and a liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 includes a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 4a is the same as the liquid crystal alignment film 4a in FIG. 1 described above. The liquid crystal alignment film 2h is the same as the liquid crystal alignment film 2c in FIG. 1 described above. In this IPS LCD element 1, when a voltage is applied to the surface electrodes 2e and the linear electrodes 2g, an electric field is generated between the surface electrodes 2e and the linear electrodes 2g as indicated by electric force lines L.

[0153] The present invention will be specifically described below with reference to examples, but the present invention should not be construed as being limited to these examples. The abbreviations of the compounds and the methods for measuring the respective properties are as follows.

[0154] (Radical polymerizable monomer that is compatible with liquid crystal and exhibits weak anchoring properties)

[0155] (Radical polymerizable monomer having a group reactive with polymer (A)) (Boc represents a tert-butoxycarbonyl group.)

[0156] (RAFT agent)

[0157] (Thermal polymerization initiator)

[0158] (RAFT removal agent)

[0159] (Grafting catalyst)

[0160] (Carboxylic Acid Capping Agent)

[0161] (diamine)

[0162] (Diisocyanate)

[0163] (Tetracarboxylic acid dianhydride)

[0164] (Additives)

[0165] (Reagents used for deprotection) TFA: trifluoroacetic acid TEA: triethylamine

[0166] (Solvent) THF: Tetrahydrofuran NMP: N-methyl-2-pyrrolidone DEAc: N,N-diethylacetamide MPA: 3-methoxy-N,N-dimethylpropanamide PGMEA: 2-methoxy-1-methylethyl acetate PGME: Propylene glycol monomethyl ether BCA: Ethylene glycol monobutyl ether acetate PB: Propylene glycol monobutyl ether

[0167] (Viscosity Measurement) The viscosity of the polyamic acid solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample amount of 1.1 mL (milliliters), a cone rotor TE-1 (1°34', R24), and a temperature of 25°C.

[0168] (Molecular Weight Measurement) (THF-GPC) The molecular weights of synthetic polymers other than polyimide precursors and polyimides were measured using a room temperature gel permeation chromatography (GPC) apparatus (CBM-20A) (Shimadzu Corporation) and a column (Shodex (registered trademark) KF-804L and KF-803L in series) (Resonac Corporation) as follows: Column temperature: 40°C Eluent: tetrahydrofuran Flow rate: 1.0 mL / min Standard sample for preparing a calibration curve: standard polystyrene (molecular weights: 197,000, 55,100, 12,800, 3,950, 1,260) (Tosoh Corporation).

[0169] (DMF-GPC) The molecular weights of the polyimide precursor and polyimide were measured using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Resonac Corporation) and columns (GPC KD-803 and GPC KD-805 in series) (manufactured by Resonac Corporation) as follows: Column temperature: 50°C Eluent: N,N-dimethylformamide (containing lithium bromide monohydrate (LiBr.H) as an additive). ２ o-Phosphoric acid) at 30 mmol / L (liter), anhydrous crystalline phosphoric acid (o-phosphoric acid) at 30 mmol / L, tetrahydrofuran (THF) at 10 mL / L) Flow rate: 1.0 mL / min Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0170] <Measurement of imidization rate> 20 mg of polyimide powder was placed in an NMR sample tube (NMR sampling tube standard, φ5 (Kusano Scientific Co., Ltd.)) and ６ 1.0 mL of a mixture of 1-dimethylethyl methyl silane (DMSO) and 0.05% tetramethylsilane (TMS) was added and sonicated to completely dissolve the solution. This solution was subjected to 500 MHz proton NMR measurement using a Fourier transform superconducting nuclear magnetic resonance (FT-NMR) "AVANCE III" (manufactured by BRUKER). The (chemical) imidization ratio was determined by determining a proton derived from a structure that remains unchanged before and after imidization as the reference proton, and using the integrated peak value of this proton and the integrated peak value of a proton derived from the NH group of the amic acid appearing around 9.5 to 10.0 ppm according to the following formula. In the formula, x represents the integrated peak value of the proton derived from the NH group of the amic acid, y represents the integrated peak value of the reference proton, and α represents the ratio of the number of reference protons to one proton of the NH group of the amic acid in the case of polyamic acid (with an imidization ratio of 0%). Imidization rate (%) = (1 - α x / y) x 100

[0171] Synthesis of Monoblock Polymers (Synthesis Example 1-1) A-1 (10.0 g, 70.3 mmol), R-3 (454.2 mg, 1.13 mmol), and AIBN (92.4 mg, 0.563 mmol) were weighed into a 100 ml recovery flask equipped with a stirrer and a nitrogen inlet tube, and THF (10.5 g) was added. After stirring at room temperature to dissolve, the system was purged with nitrogen and heated and stirred in an oil bath set to 60°C for 24 hours. After heating and stirring, the reaction solution was gently poured into cold methanol (30.0 g) while stirring to precipitate a solid, and the mixture was stirred for 30 minutes. The precipitate was separated by filtration and again subjected to slurry washing with cold methanol (30.0 g) for 30 minutes twice, and the solid was vacuum dried at 50°C to obtain monoblock polymer p(A-1). GPC measurement results showed Mn: 7,700 and Mw: 8,300.

[0172] (Synthesis Examples 1-2 to 1-7) Monoblock polymers p(A-2) to p(A-1 / A-3) shown in Table 1 below were obtained by carrying out the same procedure as in Synthesis Example 1-1, except that the types, amounts of raw materials (monomers) used, and ratios of control agent to raw materials were replaced with those shown in Table 1 below.

[0173] Synthesis of Diblock Polymers (Synthesis Example 2-1) In a 100 ml recovery flask equipped with a stirrer and a nitrogen inlet tube, p(A-1) (7.35 g, 0.955 mmol), B-1 (3.00 g, 11.9 mmol), and AIBN (78.4 mg, 0.478 mmol) were weighed out, and THF (10.4 g) was added. After stirring at room temperature to dissolve, the system was purged with nitrogen and heated and stirred in an oil bath set to 60°C for 12 hours. After heating and stirring, the reaction solution was gently poured into cold methanol (30.0 g) while stirring to precipitate a solid, and the mixture was stirred for 30 minutes. The precipitate was separated by filtration and again subjected to slurry washing with cold methanol (30.0 g) for 30 minutes twice, and the solid was vacuum dried at 50°C to obtain diblock polymer p(A-1)-(B-1). As a result of GPC measurement, Mn was 10,200 and Mw was 11,800.

[0174] Synthesis Examples 2-2 to 2-12 Diblock polymers p(A-2)-(B-1) to p(A-2)-(B-4 / B-5) shown in Table 2 below were obtained by performing the same procedure as in Synthesis Example 2-1, except that the types, amounts, and polymerization concentrations of the raw materials (polymers and monomers) used were replaced with those shown in Table 2 below.

[0175]

[0176] <Conversion of Terminal Functional Groups of Monoblock Polymer> (Synthesis Example 2-13) p(A-2) (5.00 g, 0.555 mmol) obtained in Synthesis Example 1-2 was weighed into a 100 ml recovery flask equipped with a stirrer and a nitrogen inlet tube, and THF (5.00 g) was added. The mixture was stirred and diluted at room temperature. The atmosphere in the system was replaced with nitrogen, and AM-1 (144.7 mg, 2.407 mmol) was added, followed by stirring at 50°C for 6 hours. After confirming that the reaction solution had become transparent, the reaction solution was gently poured into cold methanol (40 g) while stirring to precipitate a solid, and the mixture was stirred for 30 minutes. The precipitate was separated by filtration and again subjected to slurry washing twice with cold methanol (40 g) for 30 minutes. The solid was then vacuum dried at 50°C to obtain monoblock polymer p(A-2)SH. The number average molecular weight (Mn): 9,000, and the weight average molecular weight (Mw): 9,500.

[0177] <Deprotection of Diblock Polymer> (Synthesis Example 2-14) In a 100 ml recovery flask equipped with a stirrer and a nitrogen inlet tube, p(A-2)-(B-2) (5.00 g, 0.442 mmol) obtained in Synthesis Example 2-8 was weighed out, THF (5.00 g) was added, and the mixture was stirred and diluted at room temperature. TFA (0.894 g, 7.84 mmol) was gently added in an ice bath, and the mixture was heated and stirred at 50°C for 6 hours. After heating and stirring, TEA was added to the reaction solution to neutralize it, and the reaction solution was gently poured into cold methanol (40 g) while stirring to precipitate a solid, and the mixture was stirred for 30 minutes. The precipitate was separated by filtration and again subjected to slurry washing with cold methanol (40 g) for 30 minutes twice, and the solid was vacuum dried at 50°C to obtain diblock polymer p(A-2)-(B-7). The number average molecular weight (Mn): 10,100, and the weight average molecular weight (Mw): 12,800.

[0178] Synthesis Example 2-15: In a 100 ml recovery flask equipped with a stirrer and a nitrogen inlet tube, p(A-2)-(B-3) (5.00 g, 0.436 mmol) obtained in Synthesis Example 2-9 was weighed out, and THF (5.00 g) was added. The mixture was stirred and diluted at room temperature. TFA (0.878 g, 7.70 mmol) was gently added in an ice bath, and the mixture was heated and stirred at 50°C for 6 hours. The reaction solution was then gently poured into cold methanol (40 g) with stirring to precipitate a solid, and the mixture was stirred for 30 minutes. The precipitate was separated by filtration and again subjected to slurry washing twice with cold methanol (40 g) for 30 minutes. The solid was then vacuum dried at 50°C to obtain diblock polymer p(A-2)-(B-8). The number average molecular weight (Mn): 10,600, and the weight average molecular weight (Mw): 11,900.

[0179] Synthesis of Polyamic Acid / Polyimide (Synthesis Example 3-1) DA-2 (4.49 g, 18.4 mmol) and DA-4 (1.35 g, 4.60 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (57.9 g) was added. The mixture was stirred and dissolved under a nitrogen atmosphere. TC-1 (4.38 g, 22.3 mmol) was then added while maintaining the temperature at 10°C or below in an ice bath, and the mixture was heated and stirred at room temperature under a nitrogen atmosphere for 18 hours to obtain a solution of polyamic acid (PAA-1) with a viscosity of approximately 760 mPa s and a solids concentration of 15% by mass. The molecular weight of this polyamic acid was Mn: 11,300, Mw: 32,800.

[0180] Synthesis Example 3-2: DA-1 (0.779 g, 7.20 mmol), DA-2 (2.93 g, 12.0 mmol), and DA-4 (1.40 g, 4.80 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (41.7 g) was added. The mixture was stirred and dissolved under a nitrogen atmosphere. TC-2 (5.30 g, 23.6 mmol) was then added while maintaining the temperature at 10°C or below in an ice bath, and the mixture was heated and stirred at room temperature under a nitrogen atmosphere for 18 hours to obtain a solution of polyamic acid (PAA-2) with a viscosity of approximately 1460 mPa s and a solids concentration of 20% by mass. The molecular weight of this polyamic acid was Mn: 13,400, Mw: 33,600.

[0181] Synthesis Example 3-3: DA-3 (4.81 g, 16.8 mmol) and DA-4 (1.23 g, 4.20 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (24.2 g) was added. After stirring and dissolution under a nitrogen atmosphere, TC-3 (2.63 g, 10.5 mmol) was added while maintaining the temperature below 10°C in an ice bath, and the mixture was allowed to react for 6 hours at 50°C under a nitrogen atmosphere. After returning the temperature to room temperature, TC-1 (2.04 g, 10.4 mmol) and DEAc (10.5 g) were added, and the mixture was heated and stirred at room temperature for 18 hours to obtain a solution of polyamic acid (PAA-3) with a viscosity of approximately 1620 mPa s and a solids concentration of 20% by mass. The molecular weight of this polyamic acid was Mn: 10,200, Mw: 29,700.

[0182] Synthesis Example 3-4: The polyamic acid (PAA-3) solution (40.0 g) obtained above was weighed into a 300 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, and NMP (74.3 g) was added and stirred at room temperature for a while. After that, acetic anhydride (5.61 g, 55.0 mmol) and pyridine (2.90 g, 36.7 mmol) were added and stirred at room temperature for 30 minutes under a nitrogen atmosphere, followed by heating and stirring at 50 ° C. under a nitrogen atmosphere for 3 hours. The reaction solution was then slowly poured into methanol (500 mL) cooled to below 10 ° C. with stirring to precipitate a solid, and the mixture was stirred for 10 minutes. The precipitate was separated by filtration and again subjected to slurry washing with methanol (200 mL) for 30 minutes twice, and the solid was vacuum dried at 80 ° C. to obtain the desired polyimide powder (SPI-1) (7.04 g, yield 88%). The imidization rate of this polyimide was 48%, and the molecular weights thereof were Mn: 9,800 and Mw: 28,800.

[0183] Synthesis Example 3-5 DA-3 (6.01 g, 21.0 mmol) was weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (60.0 g) was added. The mixture was stirred and dissolved under a nitrogen atmosphere. TC-4 (4.57 g, 20.4 mmol) was then added while maintaining the temperature at 10°C or below in an ice bath, and the mixture was heated and stirred at 50°C for 24 hours to obtain a solution of polyamic acid (PAA-4) with a viscosity of approximately 620 mPa s and a solids concentration of 15% by mass. The molecular weight of this polyamic acid was Mn: 14,400, Mw: 36,500.

[0184] Synthesis Example 3-6 DA-5 (3.83 g, 19.2 mmol) and DA-4 (1.40 g, 4.80 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (59.1 g) was added. The mixture was stirred and dissolved under a nitrogen atmosphere. TC-4 (5.19 g, 23.2 mmol) was then added while maintaining the temperature at 10°C or below in an ice bath, and the mixture was heated and stirred at 50°C for 24 hours to obtain a solution of polyamic acid (PAA-5) with a viscosity of approximately 650 mPa s and a solids concentration of 15% by mass. The molecular weight of this polyamic acid was Mn: 13,700, Mw: 36,600.

[0185] Synthesis Example 3-7 DA-6 (4.69 g, 19.2 mmol) and DA-4 (1.40 g, 4.80 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (63.8 g) was added. The mixture was stirred and dissolved under a nitrogen atmosphere. TC-4 (5.16 g, 23.0 mmol) was then added while maintaining the temperature at 10°C or below in an ice bath, and the mixture was heated and stirred at 50°C for 24 hours to obtain a solution of polyamic acid (PAA-6) with a viscosity of approximately 7100 mPa s and a solids concentration of 15% by mass. The molecular weight of this polyamic acid was Mn: 12,300, Mw: 33,300.

[0186] The polyamic acids and polyimides synthesized above are shown in Table 3.

[0187]

[0188] Synthesis of Polyurea (Synthesis Example 4-1) DA-6 (4.69 g, 19.2 mmol) and DA-4 (1.40 g, 4.80 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (18.1 g) was added. The mixture was stirred and dissolved under a nitrogen atmosphere, and then DI-1 (5.94 g, 23.8 mmol) was added while maintaining the temperature at 10°C or less in an ice bath. The mixture was heated and stirred at 40°C under a nitrogen atmosphere for 18 hours to obtain a solution of polyurea (PU-1) with a viscosity of approximately 670 mPa s and a solids concentration of 40% by mass. The molecular weight of this polyurea was Mn: 6,900, Mw: 14,300.

[0189] Synthesis Example 4-2 DA-6 (4.69 g, 19.2 mmol) and DA-4 (1.40 g, 4.80 mmol) were weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, and DEAc (17.1 g) was added. The mixture was stirred and dissolved under a nitrogen atmosphere, and then DI-2 (5.28 g, 23.8 mmol) was added while maintaining the temperature at 10° C. or less in an ice bath. The mixture was heated and stirred at 40° C. for 18 hours under a nitrogen atmosphere to obtain a solution of polyurea (PU-2) with a viscosity of approximately 610 mPa s and a solids concentration of 40% by mass. The molecular weight of this polyurea was Mn: 7,200, Mw: 14,400.

[0190] (Synthesis Example 4-3) DA-3 (6.87 g, 24.0 mmol) was weighed into a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, DEAc (14.8 g) was added, and the mixture was stirred and dissolved under a nitrogen atmosphere. TC-3 (3.00 g, 12.0 mmol) was added while maintaining the temperature at 10 ° C. or less in an ice bath, and the mixture was heated and stirred at 50 ° C. for 6 hours under a nitrogen atmosphere. The reaction solution was then cooled to 10 ° C. or less in an ice bath, DI-1 (2.97 g, 11.9 mmol) and DEAc (4.5 g) were added, and the mixture was heated and stirred at 50 ° C. for 6 hours under a nitrogen atmosphere to obtain a solution of polyurea (PU-3) with a viscosity of approximately 760 mPa s and a solids concentration of 40% by mass. The molecular weight of this polyurea was Mn: 10,100, Mw: 26,700.

[0191]

[0192] <Synthesis of Graft Polymer> (Synthesis Example 5-1) Into a 30 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube, p(A-1)-(B-1) (0.100 g) obtained in Synthesis Example 2-1 and the 15 wt % PAA-1 solution obtained in Synthesis Example 3-1 (2.67 g: polymer PAA-1 was 0.4 g) were weighed out, and DEAc (2.23 g) was added and stirred at room temperature to dissolve. Thereafter, the mixture was heated and stirred at 100°C for 12 hours to synthesize graft p. 1. The grafting rate of this graft polymer was 68.2%, and the molecular weight was Mn: 26,200, Mw: 467,600.

[0193] (Synthesis Examples 5-2 to 5-28) Graftp. 2 to 28 shown in Tables 5-1 and 5-2 were obtained by carrying out the same procedure as in Synthesis Example 5-1, except that the types of raw materials (polymers) used, the amounts of the catalysts and the amounts thereof, the heating temperature, and the heating time were replaced with those shown in Tables 5-1 and 5-2 below.

[0194] (Measurement of Graft Ratio) The graft ratio of a graft copolymer is an important index that can roughly estimate the reaction rate between polymer (A) and polymer (B) and evaluate the precision of the produced graft copolymer. The graft ratio is measured by THF-GPC based on the consumption rate of polymer (B) before and after grafting. The graft ratio is calculated using the following equation (eq2):

[0195]

[0196] (Peak Intensity Before Grafting) In (eq. 2), (Peak Intensity Before Grafting) is the peak intensity of a 1.0 wt % hexane solution of the polymer (B) used in the synthesis of the graft copolymer, as determined by THF-GPC.

[0197] (Peak intensity after grafting) For (peak intensity after grafting) in (eq2), the residual peak of polymer (B) contained in the reaction solution after grafting was used. The residual peak intensity of polymer (B) was calculated by the following method. 1.0 g of hexane was added to 1.0 g of the reaction solution after grafting, and the mixture was stirred at room temperature for 1 hour to separate into aggregates containing the residue of the graft copolymer or polymer (A) and a liquid containing the residue of polymer (B) soluble in hexane. Furthermore, this liquid was filtered using a filter with 0.1 μm pores and measured by THF-GPC. The peak intensity at the discharge time corresponding to polymer (B) in the GPC chart was used as (peak intensity after grafting).

[0198] The evaluation was carried out by the above-mentioned method except for graft p. 12, 13, and 18. For graft p. 12, the peak intensity of a 2.0 wt % hexane solution of polymer (B) measured by THF-GPC was used as the peak intensity before grafting, and for graft p. 13 and 18, the peak intensity of a 0.5 wt % hexane solution of polymer (B) measured by THF-GPC was used as the peak intensity before grafting.

[0199] (Measurement of Molecular Weight of Graft Copolymer) The molecular weight of the graft copolymer, like the grafting rate, is an important index for evaluating the production of the graft copolymer of the present invention. As the grafting reaction progresses, the molecular weight of the graft copolymer increases compared to the raw materials, polymer (A) and polymer (B). All of the molecular weight data listed in Tables 5-1 and 5-2 were measured by THF-GPC on polyamic acid (PAA), polyimide (SPI), or polyurethane (PAU) solubilized in THF by chemically modifying the carboxylic acid residue or hydroxyl group residue. The chemical modification of the carboxylic acid was carried out by adding 0.115 g of the carboxylic acid capping agent DBSA to 1.00 g of a DEAc solution containing 10 wt % of the graft copolymer obtained in Synthesis Example 5-1 and stirring at room temperature for 1 hour. This makes it possible to measure graft copolymers containing PAA, SPI, or PAU by THF-GPC.

[0200]

[0201] Regarding raw material 2 of the synthesis examples shown in Tables 5-1 and 5-2, the blending amount of the polymer solution is shown for PAA-1 to PAA-6 and PU-1 to PU-3. The blending amount of the polymer itself is shown for SPI-1 and the diblock polymer.

[0202] The graft copolymer of the present invention is characterized by the grafting of a polymer (A) selected from polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, and a polymer (B) that is compatible with liquid crystal and exhibits weak anchoring properties. Synthesis Examples 5-12 and Reference Examples 1 and 2 show that the amount of p(A-2)-(B-1) detected in the reaction solution was reduced by grafting, and the grafting rate reached 55.9% (Synthesis Example 5-12). Furthermore, the molecular weight of the graft copolymer was significantly increased compared with the molecular weights of the raw materials p(A-2)-(B-1) and PAA-4, clearly demonstrating that grafting had progressed. Note that, in the above-mentioned calculation method for the grafting rate, even if the grafting rate was 0%, the grafting rate would not be 0% due to the influence of adsorption to the polymer (A).

[0203] <Preparation of Weak Anchoring Liquid Crystal Alignment Agent> (Preparation Example 1) Into a 20 mL vial equipped with a stirrer, 2.5 g of the graft copolymer solution graft p.1 obtained in Synthesis Example 5-1 was weighed out, 1.5 g of DEAc and 1.0 g of PB were added, and the mixture was stirred at room temperature for 1 hour to obtain a weak anchoring liquid crystal aligner (WAS-1).

[0204] (Preparation Examples 2 to 31) Weak anchoring liquid crystal aligning agents (WAS-2) to (WAS-31) shown in Table 6 were obtained by carrying out the same procedure as in Preparation Example 1, except that the polymer used was replaced with one shown in Table 6. Note that (WAS-30) and (WAS-31) are comparative examples.

[0205]

[0206] (Fabrication of Liquid Crystal Display Element) The fabrication method of a liquid crystal cell for evaluating the liquid crystal alignment and electro-optical response is described below. First, a substrate with electrodes was prepared. The substrate was a non-alkali glass substrate measuring 30 mm x 35 mm and 0.7 mm thick. On the substrate, ITO (indium tin oxide) electrodes with a comb-shaped pattern were formed, with an electrode width of 3 μm, an electrode spacing of 6 μm, and an angle of 10° with respect to the long side of the substrate, forming pixels. The size of each pixel was 10 mm long and approximately 5 mm wide. Hereinafter, this will be referred to as an IPS substrate. Next, the weak anchoring liquid crystal alignment agents (WAS-1 to WAS-31) obtained by the above method and the liquid crystal alignment agent for horizontal alignment (SE-6414, NRB-U973 (Nissan Chemical Industries, Ltd.)) were each filtered through a filter with a pore size of 1.0 mm, and then applied and formed into a film by spin coating on the prepared IPS substrate and a glass substrate (hereinafter referred to as the counter substrate) having an ITO film formed on the back surface and columnar spacers 3.0 μm in height. Next, after drying for 2 minutes on a hot plate at 80 ° C, it was baked for 30 minutes in a far-infrared heating furnace (IR furnace) at 230 ° C to obtain a coating film with a thickness of 100 nm. The coating film on the IPS substrate was subjected to an alignment treatment in the direction along the comb-tooth direction, and the coating film on the counter substrate was subjected to an alignment treatment in the direction perpendicular to the comb-tooth electrode. In the alignment treatment, a rubbing method was used for SE-6414, a photo-alignment method was used for NRB-U973, and no alignment treatment was performed for WAS-1 to WAS-31, and the baked substrate was used as is. The rubbing method was performed using a rubbing device manufactured by Iinuma Gauge Co., Ltd., a rubbing cloth (YA-20R) manufactured by Yoshikawa Kako Co., Ltd., a rubbing roller (diameter 10.0 cm), a stage feed speed of 30 mm / s, a roller rotation speed of 700 rpm, and a pressing pressure of 0.3 mm. The photo-alignment method was performed using a UV exposure device manufactured by Ushio Inc., and linearly polarized UV with an extinction ratio of approximately 26:1 was irradiated at a dose of 300 mJ / cm based on a wavelength of 254 nm. ２The substrate was then irradiated with polarized UV light until the alignment angle was 100°C, followed by heating in a far-infrared heating furnace (IR furnace) at 230°C for 30 minutes to perform an alignment treatment. The two substrates described above were then combined in the combinations shown in Tables 7 to 10 below so that the alignment directions were parallel. The periphery was sealed (sealant: XN-1500T (Mitsui Chemicals)), leaving a liquid crystal injection port, to prepare an empty cell with a cell gap of approximately 3.0 μm. Liquid crystal (MLC-3019 (Merck)) was injected into this empty cell under vacuum at room temperature, and the injection port was then sealed to form a liquid crystal cell with antiparallel alignment. The resulting liquid crystal cell constitutes an IPS-mode liquid crystal display element. The resulting liquid crystal cell was then heat-treated at 120°C for 10 minutes to obtain a liquid crystal display element.

[0207] (Evaluation of Initial Alignment) Using a polarizing microscope, the polarizing plates were set to crossed Nicols, and the liquid crystal cell was fixed in a state where the brightness of the liquid crystal cell was minimum. The liquid crystal cell was then rotated by 1° from there, and the alignment state of the liquid crystal was observed. When alignment defects such as unevenness or domains were not observed or were very slight, the result was rated as "good", and when they were clearly observed, the result was rated as "bad".

[0208] (Measurement of V-T curve and evaluation of driving threshold voltage, maximum brightness voltage, and transmittance) A white LED backlight and a brightness meter were set so that their optical axes were aligned, and a liquid crystal cell (liquid crystal display element) with a polarizer attached was set between them so that the brightness was minimized. A voltage was applied up to 8 V in 1 V intervals, and the brightness at each voltage was measured to measure the V-T curve. The voltage (Vmax) at which the brightness was maximized was estimated from the obtained V-T curve. Furthermore, the maximum transmittance (Tmax) was estimated by comparing the maximum transmission brightness in the V-T curve with the transmission brightness in a parallel Nicol state, which was set to 100%, through the liquid crystal cell with no voltage applied.

[0209] (Measurement of response time (Ton, Toff)) Using the same device as used in the measurement of the V-T curve above, a luminance meter was connected to an oscilloscope to measure the response speed (Ton) when a voltage that resulted in maximum luminance was applied and the response speed (Toff) when the voltage was returned to 0 V.

[0210] (Azimuthal anchoring strength (A ２Measurement of the azimuthal anchoring strength A of the strong anchoring liquid crystal alignment films SE-6414 and NRB-U973 ２ , ＳＡ The azimuthal anchoring strength A of the weak anchoring liquid crystal alignment film was measured separately by a torque balance method. ２，ＷＡ was calculated from the following equations (eq3) and (eq4) using the driving threshold voltage (Vth) obtained from the V-T curve measurement of the liquid crystal cell prepared above. －５ [J / m ２ ] is a weak anchoring liquid crystal alignment film, －４ [J / m ２ ] is a strong anchoring liquid crystal alignment film.

[0211]

[0212]

[0213] Here, V ｔｈ，ＳＡ is the driving threshold voltage of the strong anchoring liquid crystal cell, V ｔｈ，ＷＡ represents the driving threshold voltage of the weak anchoring liquid crystal cell, l is the distance between the comb electrodes, d is the cell gap, and K ２ is the twist elastic constant of the liquid crystal, ε ０ is the dielectric constant of the liquid crystal in a vacuum, and Δε is the dielectric anisotropy of the liquid crystal. The above equation eq4 is originally a calculation formula when weak anchoring liquid crystal alignment films are used on both substrates, so it cannot calculate the exact azimuthal anchoring strength of the weak anchoring liquid crystal alignment film, but it is used as an approximation of the azimuthal anchoring strength of the weak anchoring liquid crystal alignment film.

[0214] <Evaluation of Cell Characteristics Using Photo-Alignment> (Evaluation Results of Weak Anchoring IPS Characteristics) The evaluation results are shown in Table 7. Table 7 shows the azimuthal anchoring strength (A ２ ) measurement results are also shown.

[0215]

[0216] By using the graft copolymers of the present invention (Examples 1 to 30), it was confirmed that the transmittance was improved by about 20% to 30% and the driving voltage was reduced compared to the strong anchoring alignment agent (Comparative Example 3). In addition, the azimuthal anchoring energy was 2.7 × 10 －６ This demonstrates that the use of the graft copolymer of the present invention results in the development of favorable weak anchoring properties.

[0217] The graft copolymers of the present invention (Examples 1-30) were confirmed to have lower Vth and Vmax and slightly faster response speeds when the voltage was turned off compared to a polymer alloy-type weak anchoring material (Comparative Example 1, see WO 2024 / 058164) that was a mixture of polymer (A) and polymer (B) that were not graft copolymers. This indicates that the graft copolymers of the present invention exhibit better weak anchoring properties than conventional materials. Furthermore, the polymer alloy-type weak anchoring material (Comparative Example 1) exhibited higher Vth and Vmax and slightly slower response speeds when the voltage was turned off compared to a material made of polymer (B) alone (Comparative Example 2) due to the incorporation of two poorly compatible polymer components. However, the graft copolymers of the present invention did not exhibit any deterioration in properties despite using the two poorly compatible polymer components as raw materials. This is thought to be because the two poorly compatible polymer components were combined into a single component through the grafting reaction, making them less susceptible to the effects of phase separation. As a result, the graft copolymer of the present invention can simultaneously exhibit the excellent weak anchoring properties derived from polymer (B) and the coatability, solvent selectivity, mechanical strength, volume resistivity control, and refractive index control derived from polymer (A).

[0218] As mentioned above, the graft copolymer of the present invention does not suffer from deterioration in properties even when two poorly compatible components are mixed. However, if a sufficient grafting rate is not obtained (Example 9), deterioration in properties may be observed within an acceptable range. This is because, if a sufficient grafting rate is not obtained, unreacted polymer (A) and polymer (B) account for the majority of the polymer, resulting in deterioration of the coating properties and phase separation properties. For this reason, the graft copolymer of the present invention must have a grafting rate of at least a certain level. A grafting rate of 15% or more is preferred, and a grafting rate of 30% or more is more preferred, as measured based on the amount of polymer (B) remaining before and after the grafting reaction.

[0219] The graft copolymers of the present invention (Examples 1 to 30) are characterized in that polymer (A) and polymer (B) are thermally grafted by thermosetting, but the method is not limited to this as long as a predetermined grafting rate is obtained. Furthermore, the graft copolymers of the present invention employ a method of grafting polymer (A) and polymer (B) by a thermal chemical reaction, but methods using radical reactions other than thermal methods can also be applied.

[0220] The graft copolymers of the present invention (Examples 1 to 30) exhibit excellent weak anchoring properties, an effect attributable to polymer (B) constituting the graft copolymer. In particular, segments A-1 to A-6 in polymer (B) that are compatible with liquid crystals contribute to the development of weak anchoring properties. The present inventors have previously reported weak anchoring liquid crystal alignment films using coating materials composed of block copolymers having block segments compatible with liquid crystals and block segments that are insoluble in liquid crystals or that become insolubilized by heating (see WO 2022 / 260048) and coating materials composed of graft copolymers having branch polymers compatible with liquid crystals and trunk polymers that are insoluble in liquid crystals or that become insolubilized by heating (see WO 2023 / 048278). Similar compound types and molecular weights can also be used in the graft copolymers of the present invention.

[0221] The graft copolymers of the present invention (Examples 2, 7-8, 11, 14-16, and 24-26) all exhibited favorable weak anchoring properties, indicating that the ideal grafting rate is achieved regardless of the composition or type of polymer (A). In the graft copolymer, polymer (A) is particularly responsible for maintaining coatability, solvent selectivity, seal adhesion, and mechanical strength, and the structure of polymer (A) does not significantly affect the weak anchoring properties.

[0222] The graft copolymers (Examples 11 to 13) with different ratios of polymer (A) and polymer (B) all achieved low-voltage operation, high transmittance, and good alignment quality and high-speed response. This demonstrates that good weak anchoring properties can be obtained regardless of the ratio of polymer (A) to polymer (B) constituting the graft copolymer, as long as it is within an appropriate range. A low ratio of polymer (B) deteriorates the weak anchoring properties, while a high ratio raises concerns about elution into the liquid crystal and deterioration of mechanical strength and seal adhesion. Therefore, the preferred ratio of polymer (A) to polymer (B) (weight ratio (A) / (B)) is 5.0 / 95.0 to 70 / 30, and more preferably 10 / 90 to 50 / 50.

[0223] As shown in Examples 1, 11, and 29, the graft copolymer of the present invention can provide good weak anchoring properties whether used alone or in combination with multiple graft copolymers. Therefore, the graft copolymer of the present invention can be used alone or in combination with multiple polymers. However, as mentioned above, caution is required as using the graft copolymer in combination with a polymer that is poorly compatible with the graft copolymer may result in deterioration of properties.

[0224] Examples 11 and 29 show that providing the graft copolymer of the present invention on the opposing substrate resulted in higher transmittance. This suggests that providing the graft copolymer on the opposing substrate results in a higher phase difference change before and after driving the liquid crystal, and is due to the increased effective film thickness of the drivable liquid crystal. Therefore, to achieve high transmittance, the liquid crystal or cell gap is typically designed so that the product of the birefringence difference (Δn) of the liquid crystal and the cell gap (D) is approximately 300 nm. However, since high transmittance can be achieved even when this value is 300 nm or less, it is possible to achieve even faster response times and furthermore, it can be inferred that this is effective in preventing image sticking and improving contrast.

[0225] (Image-sticking evaluation) Image-sticking properties were evaluated by measuring the luminance ratio before and after image-sticking using a weak anchoring liquid crystal alignment agent containing the graft copolymer. The film-forming process of the weak anchoring liquid crystal alignment agents (WAS-1 to 31) on a glass substrate was performed under the following two conditions: Process 1 (normal conditions) and Process 2 (harsh conditions). A liquid crystal cell was otherwise prepared in the same manner as described above. Image-sticking properties were evaluated by measuring the ratio of transmittance before and after image-sticking, using the same device as used for measuring the V-T curve, based on the driving voltage corresponding to the 32 gradations before image-sticking. The results are shown in Tables 8 and 10. Process 1: Spin-coating, 80°C hot plate baking (2 minutes), 230°C far-infrared heating oven (30 minutes). Process 2: Spin-coating, 100°C hot plate baking (2 minutes), 230°C hot plate baking (30 minutes).

[0226]

[0227] The graft copolymers of the present invention (Examples 31 to 60) exhibited good image-sticking properties regardless of Step 1 or Step 2. On the other hand, a polymer alloy-type weak anchoring material (Comparative Example 4, see WO 2024 / 058164) that was a mixture of polymer (A) and polymer (B) that was not a graft copolymer exhibited significantly worse image-sticking properties in Step 2 than in Step 1. Therefore, the graft copolymers of the present invention exhibit good image-sticking properties regardless of the film-forming process, and can therefore be said to be materials with a wider process margin. Based on the above results and the fact that the weak anchoring liquid crystal aligning agent (Comparative Example 5) consisting only of polymer (B) exhibited good image-sticking properties regardless of the process, it can be understood that the quality of the image-sticking properties in this system is largely influenced by the phase separation behavior of the poorly compatible polymer (A) and polymer (B). In particular, it can be understood that the polymer alloy-type weak anchoring material exhibits significant process dependency because the separation and aggregation behavior of each agent changes significantly depending on the drying and baking processes. In other words, since the graft copolymer of the present invention is composed of a polymer in which polymer (A) and polymer (B) are bonded together by a covalent bond, it can be said that the influence of the process is reduced.

[0228] <Evaluation of Cell Characteristics Using Rubbing Alignment> (Evaluation Results of Weak Anchoring IPS Characteristics) The evaluation results are shown in Table 9. Table 9 shows the azimuthal anchoring strength (A ２ ) measurement results are also shown.

[0229]

[0230] By using the graft copolymers of the present invention (Examples 61 to 90), it was confirmed that the transmittance was improved by about 20% to 30% and the driving voltage was reduced compared to the strong anchoring alignment agent (Comparative Example 9). In addition, the azimuthal anchoring energy was 2.7 × 10 －６ This indicates that the use of the graft copolymer of the present invention results in favorable weak anchoring properties. This is the same result as when a photo-alignment film is used on the opposing substrate side. This indicates that the graft copolymer of the present invention can exhibit favorable weak anchoring properties regardless of the alignment treatment method used for the opposing substrate.

[0231]

[0232] The graft copolymers of the present invention (Examples 91 to 120) exhibited good image sticking properties regardless of Step 1 or Step 2. This indicates that by using the graft copolymers of the present invention, it is possible to form a weakly anchoring liquid crystal alignment film with a wide process margin regardless of the alignment treatment method.

[0233] (Evaluation of Coatability and Solvent Selectivity) The polymers obtained in the above synthesis examples were each placed in a 15 mL vial, diluted with a mixed solvent of NMP / PB = 8 / 2 (mass ratio), a mixed solvent of MPA / PB = 8 / 2 (mass ratio), or a mixed solvent of DEAc / PB = 8 / 2 (mass ratio) to a solids concentration of 5 mass%, and stirred at room temperature (25°C) for 12 hours. The resulting diluted solution was applied to an alkali-free glass substrate by spin coating, and then dried on a hot plate at 100°C for 2 minutes. The state of the organic film was then observed to evaluate coatability. The evaluation criteria were as follows: "X" indicates that numerous defects, whitening, or striations were present; "△" indicates that the film could be uniformly applied but with slight defects; and "◯" indicates that the film could be uniformly applied without defects. The results are shown in Table 11.

[0234]

[0235] Examples 121 to 138 show that the graft copolymer of the present invention exhibits better coatability than a polymer alloy-type weak anchoring material (see Comparative Example 13, WO 2024 / 058164) that is a mixture of polymer (A) and polymer (B) that are not graft copolymers. Furthermore, the graft copolymer of the present invention exhibits relatively good coatability even when using solvents such as NMP and MPA, which are incompatible with weak anchoring liquid crystal aligners, suggesting that the solvent selectivity has been expanded. While the main cause of coating defects is the separation and aggregation of the two incompatible polymers (A) and (B) during the later stages of drying, it is presumed that defects do not occur in the graft copolymer of the present invention because the two polymers are covalently bonded together.

[0236] According to the present invention, a stable weak anchoring film can be manufactured by a method much simpler than conventional techniques, which enables a reduction in the process load and an improvement in yield in the actual industrial production of weak anchoring IPS. Furthermore, by using the material and method of the present invention, it is possible to suppress the occurrence of a pretilt angle associated with a narrow cell gap, while achieving faster response when the voltage is turned off, less burn-in, and higher backlight transmittance and lower voltage driving in a low-temperature environment than conventional techniques, thereby providing a material and an in-plane switching liquid crystal display element that can stably exhibit excellent characteristics.

[0237] REFERENCE SIGNS LIST 1 IPS LCD element 2 Comb-tooth electrode substrate 2a Base material 2b Linear electrode 2c Liquid crystal alignment film 2d Base material 2e Planar electrode 2f Insulating film 2g Linear electrode 2h Liquid crystal alignment film 3 Liquid crystal 4 Counter substrate 4a Liquid crystal alignment film 4b Base material L Electric field lines

Claims

1. A weak anchoring liquid crystal alignment agent used for forming a liquid crystal alignment film of a liquid crystal cell having the liquid crystal and the liquid crystal alignment film, which comprises at least one polymer (A) selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, and a polymer (B) that is compatible with the liquid crystal and exhibits weak anchoring properties, and which contains a graft copolymer in which the polymer (A) and the polymer (B) are bonded.

2. The weak anchoring liquid crystal aligning agent according to claim 1, wherein the grafting ratio of the graft copolymer is 15% or more.

3. The weak anchoring liquid crystal aligning agent according to claim 1, wherein the polymer (B) is derived from a polymer (B1) having, in its side chain structure, a group L capable of covalently bonding to the polymer (A), the group L being selected from the group consisting of a hydroxy group, a phenol group, an amino group which may be protected, an aniline group which may be protected, a thiol group which may be protected, a thiophenol group which may be protected, an epoxy group, an oxetane group, an allyl group, a vinyl group, a methacryl group, an acrylic group, an oxazoline group, an isocyanate group which may be protected, and an aldehyde group.

4. The weak anchoring liquid crystal aligning agent according to claim 1, wherein the monomer constituting the polymer (B) includes a monomer selected from the group consisting of the following formulas (1), (2), (3) and (4): (In formula (1), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, X represents a single bond, an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, or a thioether bond, and R １ represents an alkyl group having 1 to 20 carbon atoms, into which a bonding group may be inserted, and n is an integer of 1 to 2. When n is 2, two X and R １ may be the same or different.) (In formula (2), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, S represents a single bond or a saturated hydrocarbon group of 1 to 6 carbon atoms which may have a bonding group inserted therein, T represents an organic group represented by the following formula (2-T), and n is an integer of 1 to 2. When n is 2, the two Ts may be the same or different. However, when n is 2, S represents a saturated hydrocarbon group of 1 to 6 carbon atoms which may have a bonding group inserted therein.) (In formula (2-T), * represents a bonding site. X represents a single bond, an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, a thioether bond, or —Si(R １ ) (R ２ )-(R １ and R ２ each independently represents an alkyl group bonded to Si.), —Si(R ３ ) (R ４ )-O-(R ３ and R ４ each independently represents an alkyl group bonded to Si. ５ )-(R ５ represents a hydrogen atom or an alkyl group bonded to N; and Cy represents a non-aromatic cyclic group having 6 to 20 members. (In formula (3), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, R １ represents an aliphatic hydrocarbon group having a linear or branched structure and having 1 to 10 carbon atoms, and three Xs each independently represent a hydrogen atom or the following formula (3-X), provided that at least one of the three Xs represents formula (3-X): In formula (3-X), Y represents a single bond, -O-, -S-, or -N(R)- (R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms bonded to N), and * represents the bonding site. ２ , R ３ , and R ４ each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group which may have a substituent. (In formula (4), M represents a polymerizable group having a polymerizable unsaturated hydrocarbon group, and R １ ~R ３ each independently represents a single bond or an alkylene group having 1 to 6 carbon atoms into which a bonding group may be inserted; Ar represents an aromatic hydrocarbon group which may have a substituent; X １ and X ２ each independently represents a hydrogen atom or an aromatic hydrocarbon group which may have a substituent, R １ X １ and R ２ X ２ and R １ X １ and R ２ X ２ and the carbon atom bonded to R may form a ring together. １ X １ , R ２ X ２ and R ３ The total number of carbon atoms is 1 or more.) 5. The weak anchoring liquid crystal aligning agent according to claim 4, wherein M in the formulae (1), (2), (3), and (4) is each independently any of the structures represented by the following formulae: (In the formula, R １ , and R ２ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, and X, Y, and Z each independently represent an oxygen atom or a sulfur atom. １ and * ２ represents a binding site, * １ and * ２ Either one of the groups may be replaced by a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms. n represents an integer of 1 to 5.

6. A graft copolymer used to form a liquid crystal alignment film of a liquid crystal cell having a liquid crystal and the liquid crystal alignment film, comprising at least one polymer (A) selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, and polyurea, and a polymer (B) that is compatible with the liquid crystal and exhibits weak anchoring properties, wherein the polymer (A) and the polymer (B) are bonded together.

7. A liquid crystal display device obtained by using the weak anchoring liquid crystal aligning agent according to any one of claims 1 to 5.

8. The liquid crystal display element according to claim 7, which is a horizontal electric field liquid crystal display element.

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