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

Abstract

To provide a liquid crystal alignment agent by which a liquid crystal element exhibiting excellent liquid crystal alignment property and alignment uniformity and excellent in voltage holding characteristics can be obtained.SOLUTION: Liquid crystal alignment agent contains polymer [A] having partial structure (a) expressed by formula (1) as main chain. In the formula, An1 is divalent group having specific condensation ring structure. X1 and X2 are each divalent group of -S-, -NR1-, -C(=O)-, -NR1-C(=O)-, -NR1-C(=O)-NR2-, substituted or unsubstituted alkanediyl group with carbon number 1-18, or divalent group obtained by substituting some of methylene groups of substituted or unsubstituted alkanediyl group with carbon number 2-18 with -O-, -S-, -NR1-, -C(=O)-, -NR1-C(=O)-, or -NR1-C(=O)-NR2-. Ar1 and Ar2 are each divalent aromatic ring group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal element, and a polymer. [Background technology]

[0002] In recent years, with the demand for higher definition and versatility in liquid crystal elements, there has been a demand not only for further improvements in voltage retention characteristics and display quality, but also for suppression of variations in the orientation of liquid crystal within pixels that occur due to variations in the manufacturing process, etc. Variations in the orientation of liquid crystal cause variations in brightness within the plane when displaying black, which can result in a decrease in contrast in liquid crystal elements.

[0003] In order to suppress the above-mentioned decrease in contrast, it has been disclosed that a polyamic acid or polyimide obtained by using a diamine having a triple bond in the main chain and a diamine having a naphthalene ring is contained in a liquid crystal alignment agent (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 140034 Summary of the Invention [Problem to be solved by the invention]

[0005] To prevent contrast degradation in liquid crystal devices, a relatively flexible skeleton is introduced into the main chain of the polymer component of the liquid crystal alignment film. This improves the stretchability of liquid crystal alignment films formed by rubbing and the thermal reorientation of photo-aligned films. However, introducing a highly flexible skeleton into the main chain of the polymer constituting the liquid crystal alignment film is likely to reduce film density and voltage retention. Therefore, it is not yet possible to achieve both low in-plane variation in the liquid crystal alignment orientation (hereinafter referred to as "alignment uniformity") and voltage retention characteristics at the currently required display quality level, and further improvement is required. Furthermore, liquid crystal devices are also required to be resistant to stress-induced deviations in the liquid crystal alignment orientation and to have good liquid crystal alignment properties.

[0006] The present invention has been made in consideration of the above problems, and its main object is to provide a liquid crystal aligning agent that exhibits excellent liquid crystal alignment properties and alignment uniformity and is capable of obtaining a liquid crystal element having excellent voltage retention characteristics. [Means for solving the problem]

[0007] The present inventors have conducted extensive research and have found that the above-mentioned problems can be solved by forming a liquid crystal alignment film using a polymer having a specific fused ring structure in the main chain.

[0008] [1] A liquid crystal aligning agent containing a polymer [A] having a partial structure (a) represented by the following formula (1) in its main chain: [ka] (In formula (1), An 1 is a divalent group having a substituted or unsubstituted fused ring structure comprising a plurality of aromatic monocyclic rings, wherein one hydrogen atom is removed from each of two different rings among the plurality of aromatic monocyclic rings constituting the fused ring, or one hydrogen atom is removed from each of two different rings among the plurality of aromatic monocyclic rings contained in a substituent of the fused ring structure. 1 and X 2are each independently -S-, -NR 1 -, -C(=O)-, -NR 1 -C(=O)-, -NR 1 -C(=O)-NR 2 -, a substituted or unsubstituted alkanediyl group having 1 to 18 carbon atoms, or a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms in which some methylene groups are -O-, -S-, or -NR 1 -, -C(=O)-, -NR 1 -C(=O)- or -NR 1 -C(=O)-NR 2 -substituted divalent radicals (except An 1 When X in formula (1) has a fluorene structure, 1 and X 2 At the same time -NR 1 -If, and, An 1 When X in formula (1) has a carbazole structure, 1 and X 2 At the same time -NR 1 -C(=O)- except for the case where X 1 An is bonded to 1 Aromatic monocyclic ring in X 2 An is bonded to 1 It is different from the aromatic monocyclic ring in R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group. 1 and Ar 2 are each independently a divalent aromatic ring group. "*" represents a bond.

[0009] [2] A liquid crystal alignment film formed using the liquid crystal alignment agent according to [1] above. [3] A liquid crystal element comprising the liquid crystal alignment film of [3] above. [4] A polymer which is a polyamic acid, a polyamic acid ester, or a polyimide and has a partial structure represented by the above formula (1) in its main chain. [Effects of the Invention]

[0010] According to the liquid crystal aligning agent of the present invention, a liquid crystal device can be obtained which not only exhibits excellent liquid crystal alignment and alignment uniformity, but also has excellent voltage retention characteristics. DETAILED DESCRIPTION OF THE INVENTION

[0011] Liquid crystal alignment agent The liquid crystal aligning agent of the present disclosure contains a polymer [A] having a specific fused ring structure in the main chain. Below, each component contained in the liquid crystal aligning agent of the present disclosure and other components that are optionally blended as needed will be described. Unless otherwise specified, each component may be used alone or in combination of two or more.

[0012] In this specification, the term "hydrocarbon group" includes chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. The term "chain hydrocarbon group" refers to a linear hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure in the main chain and is composed solely of a chain structure. The chain hydrocarbon group may be saturated or unsaturated. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. The term "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure. The term "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure. The term "aromatic ring" refers to an aromatic hydrocarbon ring and an aromatic heterocyclic ring. The term "organic group" refers to an atomic group formed by removing any hydrogen atom from a carbon-containing compound (i.e., an organic compound).

[0013] The "main chain" of a polymer refers to the "trunk" portion of the polymer, which is the longest chain of atoms. It is permissible for this "trunk" portion to contain a ring structure. For example, "having a specific structure in the main chain" means that the specific structure constitutes a part of the main chain. A "side chain" refers to a portion branched from the "trunk" portion of the polymer. "(Meth)acrylo" is a term that includes acrylo and methacrylo, and "(meth)acrylate" is a term that includes acrylate and methacrylate.

[0014] <Polymer [A]> The polymer [A] has a partial structure (a) represented by the following formula (1) in its main chain. [ka] (In formula (1), An 1 is a divalent group having a substituted or unsubstituted fused ring structure comprising a plurality of aromatic monocyclic rings, wherein one hydrogen atom is removed from each of two different rings among the plurality of aromatic monocyclic rings constituting the fused ring, or one hydrogen atom is removed from each of two different rings among the plurality of aromatic monocyclic rings contained in a substituent of the fused ring structure. 1 and X 2 are each independently -S-, -NR 1 -, -C(=O)-, -NR 1 -C(=O)-, -NR 1 -C(=O)-NR 2 -, a substituted or unsubstituted alkanediyl group having 1 to 18 carbon atoms, or a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms in which some methylene groups are -O-, -S-, or -NR 1 -, -C(=O)-, -NR 1 -C(=O)- or -NR 1 -C(=O)-NR 2 -substituted divalent radicals (except An 1 When X in formula (1) has a fluorene structure, 1 and X 2 At the same time -NR 1 -If, and, An 1 When X in formula (1) has a carbazole structure,1 and X 2 At the same time -NR 1 -C(=O)- except for the case where X 1 An is bonded to 1 Aromatic monocyclic ring in X 2 An is bonded to 1 It is different from the aromatic monocyclic ring in R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group. 1 and Ar 2 are each independently a divalent aromatic ring group. "*" represents a bond.

[0015] In the above formula (1), An 1 The fused ring structure of the formula (I) is not particularly limited as long as it is a polycyclic structure containing a plurality of aromatic monocyclic rings. The aromatic monocyclic ring constituting the fused ring structure may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. Among them, the aromatic monocyclic ring constituting the fused ring structure is preferably a benzene ring or a pyridine ring. From the viewpoints of affinity and solubility with liquid crystal and ease of material availability, the number of aromatic monocyclic rings in the fused ring structure is preferably 2 or 3. When the number of aromatic monocyclic rings in the fused ring structure is two, specific examples of the fused ring structure include a naphthalene ring structure, a quinoline structure, an isoquinoline structure, a 1,8-naphthyridine structure, a fluorene structure, a carbazole structure, a dibenzofuran structure, a dibenzothiophene structure, and a dibenzothiophene-5,5-dioxide structure. 1 Specific examples of the compound having three aromatic monocyclic rings in the fused ring structure include an anthracene structure and an acridine structure.

[0016] An 1 When the fused ring structure has a substituent, examples of the substituent include a hydrocarbon group, a halogenated hydrocarbon group, an alkoxy group, a halogenated alkoxy group, an alkoxyalkyl group, an alkoxyalkoxyalkyl group, a halogen atom, and a hydroxyl group.

[0017] An 1From the viewpoint of affinity and solubility with liquid crystal, it is preferable that the compound has a substituted or unsubstituted fused ring structure containing two aromatic monocyclic rings, and specific examples thereof include divalent groups obtained by removing one hydrogen atom from each of two different rings among two or more aromatic monocyclic rings contained in a structure represented by the following formula (an-1): [ka] (In formula (an-1), B 1 and B 2 Each of X independently represents an aromatic monocycle. 3 is -C(R 3 )(R 4 )-, -O-, -S-, -NR 5 - or -SO2-. R 3 and R 4 R are each independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. 5 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a thermally detachable group. a represents an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogenated alkoxy group having 1 to 5 carbon atoms, an alkoxyalkyl group having 1 to 5 carbon atoms, an alkoxyalkoxyalkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydroxyl group. r is an integer of 0 to 6. m is 0 or 1.

[0018] In the above formula (an-1), B 1 , B 2 is preferably a benzene ring or a pyridine ring. X 3 -C(R 3 )(R 4 )-, R 3 and R 4The monovalent hydrocarbon group represented by the formula (I) is preferably an alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The alkyl group having 1 to 5 carbon atoms may be linear or branched, and examples thereof include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Examples of cycloalkyl groups having 3 to 12 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and groups in which an alkyl group is bonded to the ring of these groups. Examples of aryl groups having 6 to 12 carbon atoms include a phenyl group, a naphthyl group, and groups in which an alkyl group is bonded to the ring of these groups. R 3 and R 4 When is a substituted monovalent hydrocarbon group, examples of the substituent include an alkoxy group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogenated alkoxy group having 1 to 5 carbon atoms, an alkoxyalkyl group having 1 to 5 carbon atoms, an alkoxyalkoxyalkyl group having 1 to 5 carbon atoms, a halogen atom, and a hydroxyl group.

[0019] R 5 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a thermally detachable group. Examples of the thermally detachable group include a tert-butoxycarbonyl group (Boc group), a benzyloxycarbonyl group, a 1,1-dimethyl-2-haloethyloxycarbonyl group, an allyloxycarbonyl group, a 2-(trimethylsilyl)ethoxycarbonyl group, and a 9-fluorenylmethyloxycarbonyl group. Among these, the Boc group is particularly preferred because it has excellent thermal detachment properties and can reduce the amount of the detached structure remaining in the film.

[0020] Among the two or more aromatic monocyclic rings contained in the structure represented by the above formula (an-1), X 1 Rings and X bonded to 2 The rings bonded to X are not particularly limited as long as they are different from each other. Specifically, when m is 0 or when m is 1, X 3 -O-, -S-, -NR 5 - or -SO2-, X is present in one of the two aromatic monocyclic rings constituting the fused ring in the above formula (an-1). 1is bonded to the other aromatic monocyclic ring, and X 2 m is 1 and X 3 -C(R 3 )(R 4 )-, at least one of the two aromatic monocyclic rings constituting the fused ring in the above formula (an-1) has X 1 or X 2 may be bonded to R 3 and R 4 At least one of R is an aryl group, 3 or R 4 X in the aromatic monocyclic ring 1 or X 2 may be bonded.

[0021] Y in the above formula (an-1) a An 1 For example, when the aromatic ring structure in the above formula (an-1) is a naphthalene ring structure, Y a The monovalent group represented by X 1 may be bonded to the benzene ring on the side bonded to X 2 In addition, when the aromatic ring structure in the above formula (an-1) is a naphthalene ring structure and r is 2 or greater, only one of the benzene rings may have a substituent, or both of the benzene rings may have a substituent. r is preferably 0 to 4, and more preferably 0 to 2.

[0022] An 1 Preferred specific examples of the formula (an-1-1) include groups represented by the following formula (an-1-1), formula (an-1-2), formula (an-1-3) or formula (an-1-4). The following formula (an-1-1) and formula (an-1-2) correspond to the case where m is 0 in the above formula (an-1). The following formula (an-1-3) corresponds to the case where m is 1 in the above formula (an-1) and one of the two benzene rings constituting the fused ring has X in it. 1 is bonded to the other benzene ring, and X 2The following formula (an-1-4) corresponds to the case where m is 1 and X is bonded in the above formula (an-1). 3 -C(R 3 )(R 4 )-, R 3 and R 4 is a substituted or unsubstituted phenyl group, and R 3 X on the benzene ring 1 is bonded, and R 4 X on the benzene ring 2 This corresponds to the case where [ka] (In formula (an-1-1), formula (an-1-2), formula (an-1-3) and formula (an-1-4), Y 1 ~Y 6 are each independently an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogenated alkoxy group having 1 to 5 carbon atoms, an alkoxyalkyl group having 1 to 5 carbon atoms, an alkoxyalkoxyalkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydroxyl group. r1 to r4 are each independently an integer of 0 to 6. r5 and r6 are each independently an integer of 0 to 4. X 4 is -C(R 6 )(R 7 )-, -O-, -S-, -NR 8 - or -SO2-. R 6 and R 7 R are each independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. 8 is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a thermally detachable group. 1 " is X in formula (1) 1 and X 2 represents a bond with one of the two, and "* 2 " indicates a bond with the other.)

[0023] In the above formulas (an-1-1) to (an-1-4), R 6 or R 7 The substituted or unsubstituted monovalent hydrocarbon group represented by R 3 and R4 Specific examples of include the same groups as those exemplified above. R 8 Examples of the thermally eliminable group represented by the formula 5 When is a thermally detachable group, specific examples include the same groups as those exemplified above. r1 to r4 are preferably 0 to 4, and more preferably 0 to 2. r5 and r6 are preferably 0 to 2, and more preferably 0 or 1.

[0024] Further specific examples of the group represented by the above formula (an-1-1), formula (an-1-2), formula (an-1-3) or formula (an-1-4) include groups represented by each of the following formulas (g-1) to (g-22). [ka] (In formulas (g-1) to (g-22), "*" represents a bond.)

[0025] An 1 From the viewpoint of improving the liquid crystal alignment property in a liquid crystal element, is preferably a group having a naphthalene ring structure among the above, and specifically is preferably a group represented by the above formula (an-1-1).

[0026] An 1 When has a naphthalene ring structure, An 1 An 1 One of the two benzene rings that make up the naphthalene ring in 1 and the other is X 2 It is sufficient to bond to An 1 The benzene ring in 1 or X 2 The bonding position with An is not particularly limited. 1From the viewpoint of obtaining a liquid crystal device exhibiting good liquid crystal alignment properties and alignment uniformity, the naphthalene diyl group represented by the formula (g-3) is preferably a naphthalene-1,5-diyl group (a group represented by the formula (g-3)), a naphthalene-2,6-diyl group (a group represented by the formula (g-2)), or a naphthalene-3,7-diyl group (a group represented by the formula (g-1)). Among these, the naphthalene-2,6-diyl group or the naphthalene-3,7-diyl group is more preferred, and the naphthalene-3,7-diyl group is even more preferred, in terms of being able to enhance the effect of improving liquid crystal alignment properties.

[0027] X 1 and X 2 In R 1 and R 2 Examples of the monovalent organic group represented by R include a monovalent hydrocarbon group having 1 to 10 carbon atoms and a monovalent thermally detachable group. 1 and R 2 When is a monovalent hydrocarbon group having 1 to 10 carbon atoms, examples of the hydrocarbon group include an alkyl group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, and a monovalent aromatic hydrocarbon group having 5 to 10 carbon atoms. Of these, an alkyl group having 1 to 5 carbon atoms, a cyclohexyl group, or a phenyl group is preferred, and an alkyl group having 1 to 3 carbon atoms is more preferred.

[0028] The monovalent thermally detachable group is R 5 Specific examples of the thermally detachable group include the same groups as those exemplified above. Among these, the Boc group is particularly preferred because it has excellent thermal detachment properties and can reduce the amount of the detached structure remaining in the film.

[0029] R 1 and R 2 Among these, is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a monovalent thermally detachable group, and more preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a Boc group.

[0030] X 1 ,X 2 When X is an alkanediyl group having 1 to 18 carbon atoms, the alkanediyl group may be linear or branched. 1,X 2 Specific examples of when X is an alkanediyl group having 1 to 18 carbon atoms include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a propane-1,1-diyl group, a butane-1,4-diyl group, a butane-1,2-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, and a dodecane-1,12-diyl group. From the viewpoint of improving the liquid crystal alignment property and alignment uniformity of a liquid crystal element and obtaining a liquid crystal alignment film having high adhesion to a substrate, among these, X 1 ,X 2 The alkanediyl group having 1 to 18 carbon atoms represented by the following formula is preferably linear, and more preferably a linear alkanediyl group having 2 to 18 carbon atoms.

[0031] In addition, in order to suppress the decrease in the voltage holding ratio in the liquid crystal element, X 1 ,X 2 The number of carbon atoms in the alkanediyl group represented by X is preferably 15 or less, more preferably 10 or less, and even more preferably 5 or less. 1 ,X 2 When is a substituted alkanediyl group having 1 to 18 carbon atoms, examples of the substituent include a halogen atom (such as a fluorine atom, a chlorine atom, an iodine atom, or a bromine atom), a hydroxyl group, and the like.

[0032] X 1 ,X 2 represents a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms in which some methylene groups are -O-, -S-, or -NR 1 -, -C(=O)-, -NR 1 -C(=O)- or -NR 1 -C(=O)-NR 2 -substituted divalent group (hereinafter referred to as "divalent group F 1 "). The divalent group F 1 In the formula, the methylene groups are replaced with the heteroatom-containing groups described above, provided that they are not adjacent to each other. 1 ,X 2 is a divalent group F 1In this case, the number of methylene groups replaced by the heteroatom-containing group is not particularly limited, and may be one or more.

[0033] Divalent group F 1 In the formula, the substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms may be linear or branched. From the viewpoint of improving the liquid crystal alignment property and alignment uniformity of the liquid crystal element and obtaining a liquid crystal alignment film having high adhesion to the substrate, the divalent group F 1 The alkanediyl group in the formula (I) is preferably linear. Examples of the substituent include a halogen atom (such as a fluorine atom, a chlorine atom, an iodine atom, or a bromine atom), a hydroxyl group, and the like.

[0034] X 1 ,X 2 is a divalent group F 1 When the divalent group F 1 represents a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms in which some methylene groups are -O-, -NR 1 -or-NR 1 A group substituted with -C(=O)- is preferred.

[0035] In order to improve the liquid crystal alignment and alignment uniformity in the liquid crystal element, X 1 ,X 2 is a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms or a divalent group F 1 is preferably a divalent group F 1 It is more preferable that some of the methylene groups in the substituted or unsubstituted alkanediyl group having 4 to 18 carbon atoms are -O-, -S-, -NR 1 -, -C(=O)-, -NR 1 -C(=O)- or -NR 1 -C(=O)-NR 2 Further, from the viewpoint of suppressing a decrease in voltage holding ratio and enhancing the liquid crystal alignment property and alignment uniformity in a liquid crystal element, X 1 and X 2 One or both of the groups are -O-, -S-, or -NR 1 - or -C(=O)- and An1 Preferably, X is bonded to an aromatic monocyclic ring in 1 and X 2 Both -O-, -S-, and -NR 1 - or -C(=O)- and An 1 It is more preferable that the aromatic ring is bonded to the aromatic monocyclic ring.

[0036] In addition, X 1 ,X 2 Ga-NR 1 -An 1 When attached to an aromatic monocyclic ring in 1 - is "-NR 1 -NR in -C(=O)- 1 - may be "-NR 1 -C(=O)-NR 2 -NR in - 1 - may also be X 1 ,X 2 is -C(=O)- and An 1 When the aromatic ring is bonded to the -C(=O)-, it is expressed as "-NR 1 -C(=O)-" may be -C(=O)-.

[0037] X 1 ,X 2 Preferably, X has an alkylene chain having two or more carbon atoms, which can improve the adhesion of the liquid crystal alignment film to the substrate while maintaining the liquid crystal alignment property and alignment uniformity in the liquid crystal element. The alkylene chain preferably has 2 to 10 carbon atoms, from the viewpoint of suppressing a decrease in the voltage holding ratio. 1 ,X 2 When X has an alkylene chain having two or more carbon atoms, 1 ,X 2 may be a substituted or unsubstituted alkanediyl group, and the divalent group F 1 may be.

[0038] From the viewpoint of improving the liquid crystal alignment and alignment uniformity in the liquid crystal element, and from the viewpoint of improving the adhesion of the liquid crystal alignment film to the substrate, X 1 ,X 2is a divalent group F having an alkylene chain having two or more carbon atoms among the above. 1 Preferably, X 1 and X 2 Both -O-, -S-, and -NR 1 - or -C(=O)- and An 1 It is more preferable that the aromatic ring is bonded to the aromatic monocyclic ring.

[0039] X 1 and X 2 Specific examples of the group include groups represented by the following formulae (x-1) to (x-46). [ka] [ka] [ka]

[0040] Ar 1 and Ar 2 The divalent aromatic ring group represented by the formula (an-1) is a group in which two hydrogen atoms have been removed from the ring portion of a substituted or unsubstituted aromatic ring. Examples of the aromatic ring include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, and an anthracene ring; nitrogen-containing aromatic heterocycles such as a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and an imidazole ring; and sulfur-containing aromatic heterocycles such as a thiophene ring. When the aromatic ring has a substituent, the substituent can be selected from the group consisting of Y in the above formula (an-1). a Examples of the groups include the same groups as those represented by the following formula:

[0041] From the viewpoint of improving the liquid crystal alignment and voltage retention characteristics, Ar 1 and Ar 2 Preferably, Ar has a ring structure selected from the group consisting of a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and an imidazole ring. 1 and Ar 2Preferred specific examples of the group include groups represented by the following formulae (a-1) to (a-11). [ka] (In the formula, "*" represents a bond.)

[0042] Ar is a material that can form a liquid crystal alignment film with excellent liquid crystal alignment and voltage retention properties. 1 and Ar 2 Among the above, groups represented by formula (a-1) to formula (a-6) are preferred, and groups represented by formula (a-1) or formula (a-6) are more preferred.

[0043] The main skeleton of the polymer [A] is not particularly limited. From the viewpoints of affinity with liquid crystal molecules, mechanical strength, liquid crystal alignment, and ease of introduction of the partial structure (a) into the main chain, the polymer [A] is preferably a polymer containing a structural unit derived from a diamine having the partial structure (a). Specific examples of such a polymer [A] include polyamic acid, polyamic acid ester, polyimide, polyamide, polyenamine, etc. Among these, the polymer [A] is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

[0044] The methods for producing the polyamic acid, polyamic acid ester, and polyimide as the polymer [A] are not particularly limited, and they can be produced by appropriately combining standard methods in organic chemistry. The polyamic acid, polyamic acid ester, and polyimide as the polymer [A] will be described in detail below.

[0045] [Polyamic acid] The polyamic acid as the polymer [A] (hereinafter also referred to as "polyamic acid (A)") can be obtained, for example, by reacting a tetracarboxylic dianhydride with a diamine.

[0046] (Tetracarboxylic acid dianhydride) Examples of the tetracarboxylic acid dianhydride used in the synthesis of the polyamic acid (A) include aliphatic tetracarboxylic acid dianhydrides and aromatic tetracarboxylic acid dianhydrides. The aliphatic tetracarboxylic acid dianhydrides include chain tetracarboxylic acid dianhydrides and alicyclic tetracarboxylic acid dianhydrides.

[0047] Specific examples of the chain tetracarboxylic dianhydride include butane tetracarboxylic dianhydride, etc. Specific examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 3-oxabicyclo[3.2.1]octane-2,4-dione, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,3,5-tricarboxycyclopentylacetic dianhydride ... 6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0]octane-2,4,6,8-tetracarboxylic acid 2:3,5:6-dianhydride 2,6 ]undecane-3,5,8,10-tetraone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic dianhydride, cyclopentanetetracarboxylic dianhydride, and the like.

[0048] Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, p-phenylene bis(trimellitic monoester anhydride), ethylene glycol bis(anhydrotrimellitate), 1,3-propylene glycol bis(anhydrotrimellitate), 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 4,4'-biphthalic dianhydride, etc. In addition to the above, the tetracarboxylic dianhydrides described in JP-A-2010-97188 can also be used as the tetracarboxylic dianhydride used in the synthesis of the polyamic acid (A).

[0049] When imparting liquid crystal alignment ability to a coating film by photoalignment treatment, it is preferable to use a substituted cyclobutanetetracarboxylic dianhydride in synthesizing the polyamic acid (A), since the photoreactivity of the coating film can be increased in combination with a specific diamine. Specific examples of the substituted cyclobutanetetracarboxylic dianhydride include the compounds represented by the following formulas (t-1) to (t-6). [ka]

[0050] When a substituted cyclobutanetetracarboxylic dianhydride is used in the synthesis of polyamic acid (A), the proportion of the substituted cyclobutanetetracarboxylic dianhydride used is preferably 10 mol % or more, more preferably 30 mol % or more, and even more preferably 50 mol % or more, based on the total amount of tetracarboxylic dianhydride used in the synthesis, from the viewpoint of sufficiently increasing the photoreactivity of the coating film.

[0051] (Diamine compounds) In synthesizing the polyamic acid (A), a diamine having the partial structure (a) (hereinafter also referred to as "specific diamine") can be preferably used. The specific diamine is only required to have the partial structure represented by the above formula (1), and other structures are not particularly limited. A preferred specific example of the specific diamine is a compound represented by the following formula (2). [ka] (In formula (2), Ar 1 , X 1 , An 1 , X 2 and Ar 2 is the same as the above formula (1).

[0052] Ar in the above formula (2) 1 , X 1 , An 1 , X 2 and Ar 2 For specific examples and preferred examples of the formula (1), the explanation for the formula (1) above applies.

[0053] Specific examples of the specific diamine include the Ar 1 , X 1 , An 1 , X 2 and Ar 2 Examples of the specific diamine include compounds in which the specific examples above are combined in any order. Examples of the specific diamine include compounds represented by the following formulas (d-1) to (d-22), and compounds in which the naphthalenediyl group in the compounds represented by the following formulas (d-1) to (d-22) is replaced with a group represented by the above formulas (g-4) to (g-22). Note that "Boc" in the structural formula represents a tert-butoxycarbonyl group (the same applies hereinafter). [ka] [ka] [ka]

[0054] Among these, the specific diamine is preferably a compound having a naphthalenediyl group, since it can provide a liquid crystal device with excellent liquid crystal alignment properties. Furthermore, among the compounds represented by the above formulas (d-1) to (d-22), the compounds represented by the formulas (d-1) to (d-8) and (d-13) to (d-17) are particularly preferred, and the compounds represented by the formulas (d-1) to (d-8) and (d-13) to (d-15) are more preferred.

[0055] The diamine compound used in the synthesis of the polyamic acid (A) may be the specific diamine alone, or the specific diamine may be used in combination with a diamine not having the partial structure represented by the above formula (1) (hereinafter also referred to as "other diamines").

[0056] Examples of other diamines include aliphatic diamines, aromatic diamines, diaminoorganosiloxanes, etc. Aliphatic diamines include chain diamines and alicyclic diamines.

[0057] Specific examples of other diamines include chain diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and 1,3-bis(aminomethyl)cyclohexane; alicyclic diamines such as 1,4-diaminocyclohexane and 4,4'-methylenebis(cyclohexylamine); Examples of aromatic diamines include dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene, cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostannyl diaminobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 1 ,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, N-(2,4-diaminophenyl)-4-(4-heptylcyclohexyl)benzamide, the following formula (E-1): [ka] (In formula (E-1), X I and X II are each independently a single bond, -O-, *-COO-, or *-OCO- (where * represents a bond to the diaminophenyl group). I is an alkanediyl group having 1 to 3 carbon atoms. II R is a single bond or an alkanediyl group having 1 to 3 carbon atoms. III is an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 1 to 20 carbon atoms. a is 0 or 1. b is an integer of 0 to 3. c is an integer of 0 to 2. d is 0 or 1, provided that 1≦a+b+c≦3. Directing group-containing diamines such as compounds represented by the formula: paraphenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl-4'-aminobenzoate, 4,4'-diaminoazobenzene, 1,2-bis(4-aminophenoxy)ethane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,5-bis(4-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy) ) Heptane, Bis[2-(4-aminophenyl)ethyl]hexanedioic acid, N,N-bis(4-aminophenyl)methylamine, N,N'-di(5-amino-2-pyridyl)-N,N'-di(tert-butoxycarbonyl)ethylenediamine, 4,4'-(2,2'-oxybis(ethane-2,1-diyl)bis(oxy))dianiline, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 3,6- Diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, 1,4-bis-(4-aminophenyl)-piperazine, 3,5-diaminobenzoic acid, 1-(4-aminophenoxy)-2-(4-(4'-aminophenyl)phenoxy)ethane, 3,5-diamino-N,N-bis(pyridin-3-ylmethyl)benzamide, and compounds represented by the following formulas (f-1) to (f-33): [ka] [ka] [ka] Diamines represented by the following formula: Examples of diaminoorganosiloxanes include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, and the diamines described in JP-A-2010-97188 can also be used. As other diamines used in the synthesis of the polyamic acid (A), one type can be used alone, or two or more types can be appropriately selected and used.

[0058] In the above formula (E-1), "-X I -(R I -X II ) d The divalent group represented by "-" is preferably an alkanediyl group having 1 to 3 carbon atoms, *-O-, *-COO-, or *-O-C2H4-O- (wherein the bond marked with "*" is bonded to a diaminophenyl group). III The group represented by the formula (I) is preferably linear. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or the 3,5-position relative to the other group.

[0059] Specific examples of the compound represented by the above formula (E-1) include compounds represented by the following formulas (E-1-1) to (E-1-4). [ka]

[0060] In synthesizing the polyamic acid (A), the proportion of the specific diamine used is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on the total amount of diamine compounds used in synthesizing the polyamic acid (A). A proportion of the specific diamine used within the above range is advantageous in that it is possible to sufficiently achieve both liquid crystal alignment and alignment uniformity as well as voltage retention characteristics in a liquid crystal element. Furthermore, in synthesizing the polyamic acid (A), the proportion of the specific diamine used may be 100 mol% or less, based on the total amount of diamine compounds used in synthesizing the polyamic acid (A). When other diamines are used to impart desired properties, the proportion of the specific diamine used is preferably 90 mol% or less, more preferably 80 mol% or less, based on the total amount of diamine compounds used in synthesizing the polyamic acid (A).

[0061] (Synthesis of polyamic acid) The polyamic acid (A) can be obtained by reacting the above-mentioned tetracarboxylic dianhydride with a diamine compound, optionally together with a molecular weight modifier. The ratio of the tetracarboxylic dianhydride and the diamine compound used in the synthesis reaction of the polyamic acid (A) is preferably such that 0.2 to 2 equivalents, and more preferably 0.3 to 1.2 equivalents, of the acid anhydride group of the tetracarboxylic dianhydride are used per equivalent of the amino group of the diamine compound.

[0062] Examples of molecular weight modifiers include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. The proportion of the molecular weight modifier used is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the total of the tetracarboxylic dianhydride and diamine compounds used.

[0063] The synthesis reaction of the polyamic acid (A) is preferably carried out in an organic solvent, at a reaction temperature of preferably −20° C. to 150° C., more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

[0064] Examples of organic solvents used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Among these organic solvents, it is preferable to use one or more selected from the group consisting of aprotic polar solvents and phenolic solvents (Group 1 organic solvents), or a mixture of one or more selected from Group 1 organic solvents with one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (Group 2 organic solvents). In the latter case, the proportion of the Group 2 organic solvent used is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on the total amount of the Group 1 organic solvents and the Group 2 organic solvents.

[0065] Particularly preferred organic solvents are one or more selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol, and halogenated phenols, or a mixture of one or more of these with other organic solvents in the above-mentioned proportions. The amount (x) of the organic solvent used is preferably an amount such that the total amount (y) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 50 mass% relative to the total amount (x+y) of the reaction solution.

[0066] In this manner, a reaction solution containing the polyamic acid (A) dissolved therein is obtained. This reaction solution may be used directly for the preparation of a liquid crystal aligning agent, or the polyamic acid (A) contained in the reaction solution may be isolated and then used for the preparation of a liquid crystal aligning agent, or the isolated polyamic acid (A) may be purified and then used for the preparation of a liquid crystal aligning agent. When the polyamic acid (A) is subjected to dehydration and cyclization to form a polyimide, the reaction solution may be used directly for the dehydration and cyclization reaction, or the polyamic acid (A) contained in the reaction solution may be isolated and then used for the dehydration and cyclization reaction, or the isolated polyamic acid (A) may be purified and then used for the dehydration and cyclization reaction. The isolation and purification of the polyamic acid (A) can be carried out according to known methods.

[0067] [Polyamic acid ester] The polyamic acid ester as the polymer [A] can be obtained, for example, by [I] a method of reacting the polyamic acid (A) obtained by the above synthesis reaction with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine compound, or [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine compound.

[0068] In this specification, "tetracarboxylic acid diester" means a compound in which two of the four carboxy groups in a tetracarboxylic acid are esterified and the remaining two are carboxy groups. "Tetracarboxylic acid diester dihalide" means a compound in which two of the four carboxy groups in a tetracarboxylic acid are esterified and the remaining two are halogenated.

[0069] Examples of the esterifying agent used in the method [I] include hydroxyl group-containing compounds, acetal compounds, halides, epoxy group-containing compounds, etc. Specific examples of these include hydroxyl group-containing compounds such as alcohols (e.g., methanol, ethanol, propanol, etc.), and phenols (e.g., phenol, cresol, etc.); acetal compounds such as N,N-dimethylformamide diethyl acetal, N,N-diethylformamide diethyl acetal; halides such as methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane, etc.; and epoxy group-containing compounds such as propylene oxide, etc.

[0070] The tetracarboxylic acid diester used in Method [II] can be obtained by ring-opening the tetracarboxylic acid dianhydride exemplified in the description of the synthesis of polyamic acid (A) using an alcohol such as methanol or ethanol. The tetracarboxylic acid derivative used in Method [II] may be a tetracarboxylic acid diester alone, or may be used in combination with a tetracarboxylic acid dianhydride. Regarding the diamine compound, the specific diamine exemplified in the synthesis of polyamic acid may be used alone, or may be used in combination with other diamines.

[0071] The reaction in method [II] is preferably carried out in an organic solvent in the presence of a suitable dehydration catalyst. Examples of the organic solvent include those exemplified as those used in the synthesis of polyamic acid (A). Examples of the dehydration catalyst include 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium halide, carbonylimidazole, and phosphorus-based condensing agents. The reaction temperature is preferably −20 to 150° C., more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

[0072] The tetracarboxylic acid diester dihalide used in Method [III] can be obtained, for example, by reacting the tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as thionyl chloride. The tetracarboxylic acid derivative used in Method [III] may be the tetracarboxylic acid diester dihalide alone, or may be used in combination with a tetracarboxylic acid dianhydride. Regarding the diamine compound, the specific diamines exemplified in the description of the synthesis of polyamic acid (A) may be used alone or in combination with other diamines.

[0073] The reaction in method [III] is preferably carried out in an organic solvent in the presence of a suitable base. Examples of the organic solvent include those exemplified as those used in the synthesis of polyamic acid (A). Examples of the base that can be preferably used include tertiary amines such as pyridine and triethylamine; and alkali metals such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium, and potassium. The reaction temperature is preferably −20 to 150° C., more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

[0074] The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. The reaction solution in which the polyamic acid ester is dissolved may be used for preparing the liquid crystal aligning agent as is, or the polyamic acid ester contained in the reaction solution may be isolated and then used for preparing the liquid crystal aligning agent, or the isolated polyamic acid ester may be purified and then used for preparing the liquid crystal aligning agent. The isolation and purification of the polyamic acid ester may be carried out according to a known method.

[0075] [Polyimide] The polyimide as the polymer [A] can be obtained, for example, by imidizing the polyamic acid (A) synthesized as described above by dehydration and ring closure.

[0076] The polyimide may be a fully imidized product in which all amic acid structures contained in its precursor polyamic acid have been dehydrated and cyclized, or a partially imidized product in which only a portion of the amic acid structures have been dehydrated and cyclized, resulting in both amic acid structures and imide ring structures. The polyimide used in the reaction preferably has an imidization rate of 20% or more, more preferably 30 to 99%, and even more preferably 40 to 99%. This imidization rate is the ratio, expressed as a percentage, of the number of imide ring structures to the total number of amic acid structures and imide ring structures in the polyimide. Here, some of the imide rings may be isoimide rings.

[0077] The dehydration ring closure of the polyamic acid is preferably carried out by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution, and optionally heating the solution.

[0078] In the method of adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of polyamic acid, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per mol of the amic acid structure of the polyamic acid. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per mol of the dehydrating agent used. Examples of organic solvents used in the dehydration ring-closing reaction include the organic solvents exemplified for use in the synthesis of polyamic acid. The reaction temperature for the dehydration ring-closing reaction is preferably 0 to 180°C, more preferably 10 to 150°C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

[0079] In this way, a reaction solution containing a polyimide is obtained. This reaction solution may be used directly for the preparation of a liquid crystal aligning agent, or may be used for the preparation of a liquid crystal aligning agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, or may be used for the preparation of a liquid crystal aligning agent after isolating the polyimide, or may be used for the preparation of a liquid crystal aligning agent after purifying the isolated polyimide. These purification operations can be performed according to known methods. Alternatively, polyimide can also be obtained by imidizing a polyamic acid ester.

[0080] The polymer [A] obtained as described above preferably has a solution viscosity of 20 to 1,800 mPa·s, and more preferably 50 to 1,500 mPa·s, when made into a 15% by mass solution. The solution viscosity (mPa·s) of the polymer is a value measured at 25°C using an E-type rotational viscometer for a 15% by mass polymer solution prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0081] The weight-average molecular weight (Mw) of the polymer [A] measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn) of the polymer [A], expressed as the ratio of Mw to the number-average molecular weight (Mn) measured by GPC in terms of polystyrene, is preferably 8 or less, more preferably 6 or less. When the Mw and Mw / Mn of the polymer [A] are within the above ranges, good liquid crystal alignment properties of the liquid crystal device can be ensured.

[0082] The content ratio of the polymer [A] in the liquid crystal aligning agent of the present disclosure is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of the solid content (components other than the solvent of the liquid crystal aligning agent) contained in the liquid crystal aligning agent.

[0083] <Other ingredients> The liquid crystal aligning agent of the present disclosure may contain components (other components) other than the polymer [A]. Examples of other components include a polymer not having the partial structure represented by the above formula (1) in its main chain (hereinafter also referred to as "polymer [B]"), a crosslinking agent, a functional silane compound, an antioxidant, a metal chelate compound, a curing accelerator, a surfactant, a filler, a dispersant, a photosensitizer, an acid generator, a base generator, and a radical generator. The blending ratio of these components can be appropriately selected depending on each compound, as long as the effects of the present disclosure are not impaired.

[0084] (Polymer [B]) The polymer [B] is used, for example, for the purpose of suppressing a decrease in voltage holding ratio or improving liquid crystal alignment. The main skeleton of the polymer [B] is not particularly limited, but examples include polymers having a main skeleton of polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane, polyester, cellulose derivative, polyacetal, or addition polymer. The addition polymer is a polymer containing a structural unit derived from a monomer having a polymerizable unsaturated carbon-carbon bond, such as a styrene-based polymer, a (meth)acrylic polymer, a maleimide-based polymer, or a styrene-maleimide copolymer. Of these, the polymer [B] is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and addition polymer.

[0085] In addition, when the liquid crystal alignment agent is used for photo-alignment treatment, the polymer [A] may contain a photosensitive polymer and the polymer [B] may contain a non-photosensitive polymer. Alternatively, the polymer [A] may contain a non-photosensitive polymer and the polymer [B] may contain a photosensitive polymer. Furthermore, both the polymer [A] and the polymer [B] may contain photosensitive polymers.

[0086] When polymer [B] is contained in the liquid crystal alignment agent, the content ratio of polymer [B] is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, per 100 parts by mass of the polymer components contained in the liquid crystal alignment agent (i.e., the total amount of polymer [A] and polymer [B]).

[0087] (solvent) The liquid crystal aligning agent of the present disclosure is prepared as a liquid composition obtained by dispersing or dissolving the polymer [A] and components used as needed, preferably in a suitable solvent.

[0088] Examples of the organic solvent to be used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, and ethylene glycol-n-butyl ether ( butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. These can be used alone or in combination of two or more.

[0089] The solid content concentration in the liquid crystal aligning agent (the proportion of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected taking into consideration viscosity, volatility, etc., but is preferably in the range of 1 to 10 mass %. That is, the liquid crystal aligning agent is applied to the surface of a substrate as described below, and preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that will become a liquid crystal alignment film. In this case, if the solid content concentration is 1 mass % or more, the coating film can have a sufficient thickness, and a good liquid crystal alignment film tends to be easily obtained. If the solid content concentration is 10 mass % or less, the coating film thickness does not become too large, and an increase in the viscosity of the liquid crystal aligning agent can be suppressed, tending to improve the coatability.

[0090] The particularly preferred range of solid content varies depending on the application of the liquid crystal aligning agent and the method used to apply the liquid crystal aligning agent to a substrate. For example, when applying a liquid crystal aligning agent for a liquid crystal display device to a substrate by a spinner method, the solid content (the ratio of the total mass of all components in the liquid crystal aligning agent other than the solvent to the total mass of the liquid crystal aligning agent) is particularly preferably in the range of 1.5 to 4.5 mass%. When using a printing method, the solid content is particularly preferably in the range of 3 to 9 mass%, thereby adjusting the solution viscosity to a range of 12 to 50 mPa·s. When using an inkjet method, the solid content is particularly preferably in the range of 1 to 5 mass%, thereby adjusting the solution viscosity to a range of 3 to 15 mPa·s. The temperature when preparing the liquid crystal aligning agent is preferably 10 to 50°C, more preferably 20 to 30°C. Furthermore, with regard to the liquid crystal aligning agent for the retardation film, from the viewpoint of the applicability of the liquid crystal aligning agent and the thickness of the coating film to be formed being appropriate, the solid content concentration of the liquid crystal aligning agent is preferably in the range of 0.2 to 10 mass %, more preferably in the range of 3 to 10 mass %.

[0091] <Liquid crystal alignment film and liquid crystal element> The liquid crystal alignment film of the present disclosure is formed using the liquid crystal alignment agent prepared as described above. Furthermore, the liquid crystal element of the present disclosure includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and various modes such as TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment) (including VA-MVA, VA-PVA, etc.), IPS (In-Plane Switching), FFS (Fringe Field Switching), OCB (Optically Compensated Bend), and PSA (Polymer Sustained Alignment) can be applied. The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. In step 1, different substrates are used depending on the desired operation mode. Steps 2 and 3 are common to all operation modes.

[0092] (Step 1: Formation of coating film) First, a liquid crystal alignment agent is applied to a substrate, and the coated surface is preferably heated to form a coating film on the substrate. The substrate may be a transparent substrate made of glass such as float glass or soda glass, or plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly(alicyclic olefin). The transparent conductive film provided on one side of the substrate may be a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO2), or an ITO film made of indium oxide-tin oxide (In2O3-SnO2). When manufacturing a TN-, STN-, VA-, or PSA-type liquid crystal device, two substrates each having a patterned transparent conductive film are used. On the other hand, when manufacturing an IPS- or FFS-type liquid crystal device, one substrate has an electrode made of a transparent conductive film or metal film patterned into a comb-tooth shape, and another substrate has no electrode. The metal film may be a film made of a metal such as chromium. The liquid crystal alignment agent is preferably applied to the electrode-forming surface of the substrate by offset printing, spin coating, roll coating, or inkjet printing.

[0093] After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably carried out to prevent dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30 to 200°C, and the pre-baking time is preferably 0.25 to 10 minutes. Thereafter, if necessary, a baking (post-baking) step is carried out to completely remove the solvent or thermally imidize the amic acid structure present in the polymer. The baking temperature (post-baking temperature) at this time is preferably 80 to 300°C, and the post-baking time is preferably 5 to 200 minutes. The film thus formed preferably has a thickness of 0.001 to 1 μm. After applying the liquid crystal aligning agent to the substrate, the organic solvent is removed to form a liquid crystal alignment film or a coating film that will become a liquid crystal alignment film.

[0094] (Step 2: Alignment treatment) When producing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal device, the coating film formed in step 1 is subjected to a treatment (alignment treatment) to impart liquid crystal alignment ability. This imparts the ability to align liquid crystal molecules to the coating film, resulting in a liquid crystal alignment film. Examples of alignment treatments include a rubbing treatment in which the surface of the coating film formed on the substrate is rubbed with cotton or the like, and a photo-alignment treatment in which the coating film is irradiated with light to impart liquid crystal alignment ability. In particular, the liquid crystal aligning agent of the present disclosure is preferably used as a photo-alignment agent in which a coating film formed using the liquid crystal aligning agent is subjected to a photo-irradiation treatment to impart liquid crystal alignment ability. On the other hand, when producing a vertical alignment type (VA type) liquid crystal device, the coating film formed in step 1 can be used as a liquid crystal alignment film as is, or the coating film may be subjected to an alignment treatment. A liquid crystal alignment film suitable for a vertical alignment type liquid crystal device can also be preferably used for a PSA type liquid crystal device.

[0095] The light irradiation in the photo-alignment treatment can be performed by irradiating the coating film after the post-bake step, irradiating the coating film after the pre-bake step but before the post-bake step, or irradiating the coating film while it is being heated in at least one of the pre-bake and post-bake steps. In the photo-alignment treatment, the radiation to be irradiated to the coating film can be, for example, ultraviolet light and visible light containing light with a wavelength of 150 to 800 nm. Preferably, ultraviolet light containing light with a wavelength of 200 to 400 nm is used. When the radiation is polarized, it may be linearly polarized or partially polarized. Furthermore, when the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these. When irradiating with unpolarized radiation, the irradiation direction is an oblique direction.

[0096] The light source used may be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, or a meta Examples of the radiation that can be used include an argon resonance lamp, a xenon lamp, and an excimer laser. The radiation dose is preferably 400 to 20,000 J / m 2 and more preferably 1,000 to 5,000 J / m2 The coating film may be irradiated with light while being heated in order to enhance the reactivity.

[0097] In producing a liquid crystal alignment film, the coating film that has been subjected to light irradiation treatment may be heated within a temperature range of 120°C or higher and 280°C or lower. Such a heat treatment is preferable in that it further improves the liquid crystal alignment (thermal realignment) and results in a liquid crystal device with improved display quality. This heating may be post-baking, or may be a heat treatment that is performed separately from post-baking and after post-baking. In the heat treatment of the coating film that has been subjected to light irradiation treatment, the heating temperature is preferably 140°C or higher, more preferably 150°C to 250°C, from the viewpoint of promoting realignment of molecular chains by heating. The heating time is preferably 5 to 200 minutes, more preferably 10 to 60 minutes.

[0098] The production of a liquid crystal alignment film may further include a step of contacting the light-irradiated coating film with water, a water-soluble organic solvent, or a mixed solvent of water and a water-soluble organic solvent. Examples of water-soluble organic solvents include methanol, ethanol, 1-propanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone. Among these, water, isopropanol, and mixtures thereof are preferred as the solvent used in this step. Examples of methods for contacting the coating film with the solvent include, but are not limited to, spraying, showering, immersion, and puddling. The contact time between the coating film and the solvent is not particularly limited, but is, for example, 5 seconds to 15 minutes. After contact with the solvent, the coating film may be subjected to a heat treatment.

[0099] (Step 3: Construction of liquid crystal cell) Two substrates with liquid crystal alignment films formed thereon are prepared as described above, and a liquid crystal cell is fabricated by placing a liquid crystal between the two substrates facing each other. Examples of methods for fabricating a liquid crystal cell include: (1) placing the two substrates facing each other with a spacer between them so that the liquid crystal alignment films face each other, bonding the peripheries of the two substrates together with a sealant, injecting liquid crystal into the substrate surfaces and the cell gap defined by the sealant, and then sealing the injection hole; and (2) applying a sealant to a predetermined location on one substrate with a liquid crystal alignment film, dropping liquid crystal at several predetermined locations on the liquid crystal alignment film, and then bonding the other substrate so that the liquid crystal alignment film faces each other, and spreading the liquid crystal over the entire surface of the substrate (ODF method). The fabricated liquid crystal cell is preferably further heated to a temperature at which the liquid crystal used assumes an isotropic phase and then slowly cooled to room temperature to remove the flow alignment that occurred during liquid crystal filling.

[0100] Examples of sealing agents that can be used include epoxy resins containing a curing agent and aluminum oxide spheres as spacers. Examples of spacers that can be used include photospacers and bead spacers. Examples of liquid crystals that can be used include nematic liquid crystals and smectic liquid crystals. Among these, nematic liquid crystals are preferred, and examples that can be used include Schiff-based liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, and cubane liquid crystals. Furthermore, cholesteric liquid crystals, chiral agents, ferroelectric liquid crystals, and the like may be added to these liquid crystals.

[0101] In the PSA mode, a polymerizable compound (e.g., a polyfunctional (meth)acrylate compound) is filled into the cell gap together with the liquid crystal, and after the liquid crystal cell is constructed, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates. In producing a PSA liquid crystal element, the proportion of the polymerizable compound used is, for example, 0.01 to 3 parts by mass, preferably 0.05 to 1 part by mass, per 100 parts by mass of the total liquid crystal.

[0102] Next, if necessary, a polarizing plate is attached to the outer surface of the liquid crystal cell. Examples of polarizing plates include a polarizing film called an "H film" made by stretching and aligning polyvinyl alcohol and absorbing iodine, sandwiched between cellulose acetate protective films, or a polarizing plate made of the H film itself. This produces a liquid crystal device.

[0103] The liquid crystal element of the present disclosure can be effectively applied to various uses, for example, various display devices such as watches, portable game machines, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, and information displays, as well as light control films, etc. Furthermore, a liquid crystal element formed using the liquid crystal aligning agent of the present disclosure can also be applied to a retardation film.

[0104] According to the present disclosure described above, the following means are provided. [Means 1] A liquid crystal aligning agent containing a polymer [A] having a partial structure (a) represented by the above formula (1) in its main chain. [Means 2] The liquid crystal aligning agent according to [Means 1], wherein the polymer [A] contains a structural unit derived from a diamine having the partial structure (a). [Means 3] Said X 1 and X 2 One or both of the groups are -O-, -S-, or -NR 1 - or -C(=O)-, 1 The liquid crystal aligning agent according to [Means 1] or [Means 2], wherein the aromatic monocyclic ring is bonded to the aromatic monocyclic ring. [Means 4] The liquid crystal aligning agent according to any one of [Means 1] to [Means 3], wherein the polymer [A] is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide. [Means 5] The above-mentioned An 1 is represented by the above formula (an-1-1), formula (an-1-2), formula (an-1-3) or formula (an-1-4), the liquid crystal aligning agent according to any one of [Means 1] to [Means 4]. [Means 6] The An1 The liquid crystal aligning agent according to any one of [Means 1] to [Means 5], wherein is a substituted or unsubstituted naphthalene-2,6-diyl group or naphthalene-3,7-diyl group. [Means 7] The liquid crystal aligning agent according to any one of [Means 1] to [Means 6], further comprising a polymer [B] that does not have the partial structure (a) in its main chain. [Means 8] The liquid crystal aligning agent according to [Means 7], wherein the polymer [B] is at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and addition polymer. [Means 9] A liquid crystal alignment film formed using the liquid crystal aligning agent according to any one of [Means 1] to [Means 8]. [Means 10] A liquid crystal device comprising the liquid crystal alignment film according to [Means 9]. [Means 11] A polymer which is a polyamic acid, a polyamic acid ester or a polyimide and has a partial structure represented by the above formula (1) in its main chain. [Example]

[0105] The present invention will be explained in more detail below with reference to examples, but the present invention should not be construed as being limited by these examples.

[0106] In the following examples, the imidization rate of polyimide in a polymer solution was measured by the following method. [Imidization rate of polyimide] The polyimide solution was poured into pure water, and the resulting precipitate was thoroughly dried under reduced pressure at room temperature. After that, it was dissolved in deuterated dimethyl sulfoxide and measured at room temperature using tetramethylsilane as a standard substance. 1 H-NMR measurement was carried out. 1 The imidization rate [%] was calculated from the H-NMR spectrum using the following formula (1). Imidization rate [%] = (1 - (A 1 / (A 2 ×α)))×100 …(1) (In formula (1), A 1 is the peak area due to the proton of the NH group, which appears at a chemical shift of around 10 ppm. 2is the peak area due to other protons. α is the ratio of the number of other protons to one proton of the NH group in the polymer precursor (polyamic acid).

[0107] The required amounts of raw material compounds and polymers used in the following examples were ensured by repeating synthesis on a synthesis scale as necessary, as shown in the following synthesis examples. In the examples and comparative examples, "parts" and "%" are by mass unless otherwise specified.

[0108] The abbreviations for the compounds are as follows: In the following, the compound represented by formula (X) may be simply referred to as "compound (X)".

[0109] (Tetracarboxylic acid dianhydride) [ka]

[0110] (Diamine compounds) [ka] [ka]

[0111] [ka] [ka]

[0112] (Other compounds) [ka]

[0113] <Polymer synthesis> 1. Synthesis of polyamic acid [Synthesis Example 1] 100 parts by mole of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride (compound (TB-1)) as a tetracarboxylic dianhydride, and 40 parts by mole of compound (DA-1), 10 parts by mole of compound (DB-1), and 50 parts by mole of compound (DB-5) as diamine compounds were dissolved in N-methyl-2-pyrrolidone (NMP), and the reaction was carried out at 40°C for 6 hours to obtain a solution containing 15% by mass of polyamic acid (referred to as polymer (PAA-1)).

[0114] [Synthesis Examples 2 to 39] Polyamic acids (polymers (PAA-2) to (PAA-28) and polymers (paa-1) to (paa-11)) were obtained by the same procedure as in Synthesis Example 1, except that the types and amounts of the tetracarboxylic dianhydrides and diamine compounds used were changed as shown in Table 1. In Table 1, the numerical values ​​for the tetracarboxylic dianhydrides (acid dianhydrides 1 to 3) represent the ratio (molar ratio) of each compound to 100 parts by mole of the total amount of the tetracarboxylic dianhydrides used in the synthesis of the polyamic acid. The numerical values ​​for the diamine compounds (diamines 1 to 4) represent the ratio (molar ratio) of each compound to 100 parts by mole of the total amount of the diamine compounds used in the synthesis of the polyamic acid.

[0115] [Table 1]

[0116] 2. Polyimide Synthesis [Synthesis Example 40] 100 moles of compound (TB-1) as a tetracarboxylic dianhydride, 10 moles of compound (DA-1), 50 moles of compound (DB-5), 20 moles of compound (DB-8), and 20 moles of compound (DB-9) as diamine compounds were dissolved in NMP and reacted at 40°C for 6 hours to obtain a solution containing 15% by mass of polyamic acid. Next, NMP was added to the resulting polyamic acid solution to obtain a solution with a polyamic acid concentration of 10% by mass, and pyridine and acetic anhydride were added, followed by a dehydration ring-closing reaction at 60°C for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with fresh NMP to obtain a solution containing 15% by mass of polyimide (referred to as polymer (PI-1)) with an imidization rate of approximately 60%.

[0117] [Synthesis Examples 41 to 51] Polyimides (polymers (PI-2) to (PI-9) and (PI-1) to (PI-3)) were obtained by the same procedure as in Synthesis Example 40, except that the types and amounts of the tetracarboxylic dianhydrides and diamine compounds used were changed as shown in Table 2. In Table 2, the values ​​for the tetracarboxylic dianhydrides (acid dianhydrides 1 and 2) represent the ratio (molar ratio) of each compound to 100 parts by mole of the total amount of the tetracarboxylic dianhydrides used in the synthesis of the polyimides. The values ​​for the diamine compounds (diamines 1 to 4) represent the ratio (molar ratio) of each compound to 100 parts by mole of the total amount of the diamine compounds used in the synthesis of the polyimides.

[0118] [Table 2]

[0119] 3. Synthesis of polyorganosiloxane [Synthesis Example 52] A 1000 mL three-neck flask was charged with 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (compound (s-1)), 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine and mixed at room temperature. Next, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the mixture was stirred under reflux while reacting at 80°C for 6 hours. After the reaction was completed, the organic layer was removed and washed with a 0.2% by weight aqueous solution of ammonium nitrate until the water after washing was neutral. The solvent and water were then distilled off under reduced pressure. An appropriate amount of methyl isobutyl ketone was added to obtain a 50% by weight solution of polymer (ESSQ-1), a polyorganosiloxane having epoxy groups. In a 500 mL three-neck flask, 3.10 g of compound (c-1) (20 mol% relative to the amount of epoxy groups in the polymer (ESSQ-1)), 3.24 g of compound (c-2) (10 mol% relative to the amount of epoxy groups in the polymer (ESSQ-1)), 1.00 g of tetrabutylammonium bromide, 20.0 g of a solution containing the polymer (ESSQ-1), and 290.0 g of methyl isobutyl ketone were added and stirred at 90 ° C. for 18 hours. After cooling to room temperature, the separation and washing operation with distilled water was repeated 10 times. The organic layer was then recovered, concentrated using a rotary evaporator, and diluted with NMP twice. The solids concentration was then adjusted to 10% by mass using NMP to obtain an NMP solution of polyorganosiloxane (referred to as polymer (PSQ-1)).

[0120] 4. Synthesis of styrene-maleimide copolymer [Synthesis Example 53] Under nitrogen, 5.00 g of compound (M-1), 1.05 g of compound (M-2), 4.80 g of compound (M-3), and 2.26 g of compound (M-4) were added to a 100 mL two-neck flask as polymerization monomers, 0.39 g of 2,2'-azobis(2,4-dimethylvaleronitrile) as a radical polymerization initiator, 0.39 g of 2,4-diphenyl-4-methyl-1-pentene as a chain transfer agent, and 52.5 mL of N-methyl-2-pyrrolidone (NMP) as a solvent, and the mixture was polymerized at 70 °C for 6 hours. After reprecipitation in methanol, the precipitate was filtered and dried under vacuum at room temperature for 8 hours to obtain the target polymer (referred to as polymer (MI-1)).

[0121] <Preparation and Evaluation of Liquid Crystal Alignment Agent> [Example 1: Optical FFS type liquid crystal display element] 1. Preparation of Liquid Crystal Alignment Agent The solution containing the polymer (PAA-1) obtained in Synthesis Example 1 was diluted with NMP and BC to obtain a solution with a solvent composition of NMP / BC=80 / 20 (mass ratio) and a solid content concentration of 3.5 mass %. This solution was filtered through a filter with a pore size of 0.2 μm to prepare a liquid crystal alignment agent (AL-1).

[0122] 2. Fabrication of FFS-type LCD elements using the photoalignment method A glass substrate (referred to as the first substrate) with a flat electrode (bottom electrode), an insulating layer, and a comb-shaped electrode (top electrode) laminated in this order on one side, and a glass substrate (referred to as the second substrate) without an electrode were prepared. Next, a liquid crystal alignment agent (AL-1) was applied to the electrode-forming surface of the first substrate and one substrate surface of the second substrate using a spinner, and heated (pre-baked) on a hot plate at 80°C for 1 minute. This was followed by drying (post-baking) for 30 minutes in an oven at 230°C with the interior substituted with nitrogen, forming a coating film with an average thickness of 0.1 μm. The resulting coating film was irradiated with 1,000 J / m of linearly polarized ultraviolet light containing a 254 nm emission line using an Hg-Xe lamp. 2The coating film was then irradiated with light from the normal direction of the substrate to perform a photo-alignment treatment. The irradiation dose was measured using an actinometer measuring at a wavelength of 254 nm. The photo-aligned coating film was then heat-treated in a clean oven at 230°C for 30 minutes to form a liquid crystal alignment film. Next, an epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was applied by screen printing to the outer edge of the surface of one of the pair of substrates on which the liquid crystal alignment film was formed. The substrates were then superimposed and pressed together so that the projection directions of the polarization axes on the substrate surfaces during light irradiation were antiparallel, and the adhesive was thermally cured at 150°C for 1 hour. Next, a negative liquid crystal (MLC-6608, manufactured by Merck) was filled between the pair of substrates through the liquid crystal injection port, which was then sealed with an epoxy adhesive to obtain a liquid crystal cell. Furthermore, to eliminate flow alignment during liquid crystal injection, the cell was heated at 120°C and then slowly cooled to room temperature. The above series of operations was also performed with a post-baking UV irradiation dose of 100 to 10,000 J / m. 2 Three or more liquid crystal cells with different UV exposure doses were manufactured by changing the exposure dose within the range of , and the liquid crystal cell with the exposure dose that showed the best alignment characteristics (optimum exposure dose) was used for the evaluation of liquid crystal alignment, alignment uniformity, and VHR reliability described below.

[0123] 3. Evaluation of liquid crystal alignment The liquid crystal cell manufactured in 2 above was set to a 27,000 cd / m 2 The cells were left standing for 500 hours in front of a high-brightness backlight, and the liquid crystal alignment was evaluated by the rate of change in retardation before and after backlight irradiation. First, the retardation of the liquid crystal cell manufactured in 2 above was measured using an Axoscan manufactured by Optoscience, and the rate of change α in retardation before and after backlight irradiation was calculated using the following formula (z-1). The smaller the rate of change α, the better the liquid crystal alignment. A rate of change α of 1% or less was evaluated as "good (○)", a rate of change α of more than 1% and less than 2% was evaluated as "fair (△)", and a rate of change α of more than 2% was evaluated as "poor (×)". α=Δθ / θ1 …(z-1) (In formula (z-1), Δθ represents the difference in retardation before and after irradiation, and θ1 represents the retardation value before irradiation.) As a result, the liquid crystal alignment property of this example was evaluated as "good (◯)".

[0124] 4. Evaluation of alignment uniformity For the liquid crystal cell manufactured in 2. above, the retardation was measured at 20 points within one pixel plane using an Axoscan manufactured by Optoscience, and the standard deviation was calculated. The retardation standard deviation was evaluated as "good (○)" when it was 0.05 or less, "fair (△)" when it was greater than 0.05 and less than 0.07, and "poor (×)" when it was greater than 0.07. As a result, the alignment uniformity of this example was evaluated as "good (○)."

[0125] 5. Evaluation of VHR reliability The liquid crystal cell manufactured in 2 above was evaluated for reliability in terms of voltage holding ratio. The evaluation was performed as follows. First, a voltage of 1 V was applied to the liquid crystal cell for 60 microseconds, and then the voltage holding ratio (VHR1) was measured 1670 milliseconds after the application was removed. Next, the liquid crystal cell was irradiated with CCFL (backlight) at 60°C for one week, and then left to cool naturally at room temperature. After cooling, a voltage of 1 V was applied to the liquid crystal cell for 60 microseconds, and then the voltage holding ratio (VHR2) was measured 1670 milliseconds after the application was removed. The measurement device used was a VHR measuring device "VHR-1" manufactured by Toyo Corporation. The rate of change in VHR (ΔVHR) at this time was calculated as the difference between VHR1 and VHR2 (ΔVHR = VHR1 - VHR2), and VHR reliability was evaluated based on ΔVHR. If ΔVHR was less than 15%, it was judged as "good (○)", if it was between 15% and 20% it was judged as "fair (△)", and if it was more than 20%, it was judged as "poor (×)". As a result, in this example, the VHR reliability was "good (○)".

[0126] 6. Evaluation of adhesion to substrate The liquid crystal alignment agent (AL-1) was applied to a glass substrate using a spinner, pre-baked on a hot plate at 80°C for 2 minutes, and then heated (post-baked) for 30 minutes in an oven at 230°C with the interior replaced with nitrogen, forming a coating film with an average thickness of 0.10 μm. By repeating the same procedure, two glass substrates with coating films were produced. On the coating film of one glass substrate with a coating film formed, ODF sealant (S-WB42, manufactured by Sekisui Chemical Co., Ltd.) was applied to a width of 1 mm, and the other glass substrate was bonded so that the coating film and ODF sealant were in contact. After that, a metal halide lamp was used to apply 30,000 J / m 2 After irradiating the film with light (equivalent to 365 nm), the film was heated in an oven at 120°C for 1 hour. After heating, the adhesion strength was measured using a tension and compression tester (model number: SDWS-0201-100SL) manufactured by Imada Seisakusho, and the adhesion of the film to the substrate was evaluated. The evaluation was conducted when the adhesion strength was 200 N / cm 2 If it is above 100N / cm, it is considered "Good (○)" 2 More than 200N / cm 2 If it is less than 100N / cm, it is "Fair (△)". 2 If the adhesive strength was less than 212 N / cm, it was rated as "poor (x)". 2 The adhesion was evaluated as "good (○)."

[0127] [Examples 2 to 17 and Comparative Examples 1 to 7] A liquid crystal alignment agent was prepared in the same manner as in Example 1, except that the composition of the liquid crystal alignment agent was changed as shown in Table 3. Furthermore, using the obtained liquid crystal alignment agent, an FFS-type liquid crystal cell was produced by a photoalignment method in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 3. In Examples 11 to 14, 16, and 17 and Comparative Examples 2, 3, and 5 to 7, two types of polymers were used as the polymer component. In Table 3, the numerical values ​​in the polymer column represent the blending ratio (parts by mass) of the solid content of each polymer relative to 100 parts by mass of the total amount of the solid content (polymer component) used in preparing the liquid crystal alignment agent.

[0128] [Table 3]

[0129] As shown in Table 3, in Examples 1 to 17, which used a liquid crystal alignment agent containing a polymer [A] having a partial structure (a), the liquid crystal alignment property, alignment uniformity, and VHR reliability were improved in a well-balanced manner compared to Comparative Examples 1 to 7, which used a liquid crystal alignment agent not containing the polymer [A]. In addition, in Examples 1 to 17, the adhesion to the substrate was also evaluated as "good" or "fair."

[0130] Among these, in Examples 1 to 17, Examples 1 to 5, 9 to 13, and 15 to 17 were evaluated as "good (◯)" for the liquid crystal alignment and adhesion, indicating that the film adhesion could be improved while maintaining the liquid crystal alignment. This is thought to be because the liquid crystal alignment was further improved by having a naphthalene-2,6-diyl group or a naphthalene-3,7-diyl group in the partial structure (a), and the film adhesion could be improved while maintaining the liquid crystal alignment by including an alkylene chain having two or more carbon atoms in the partial structure (a). Note that in Comparative Example 7, although a naphthalene ring structure was introduced into the polymer by using compound (DB-22) as part of the diamine compound, the results were inferior to those of Examples 1 to 16. This is because when a structural unit derived from compound (DB-22) was introduced into the polymer main chain, the molecular chain was bent, resulting in insufficient VHR reliability, and the X 2 It is presumed that the evaluation of the liquid crystal alignment property and adhesion was "fair (△)" because the film does not have a structure corresponding to the above.

[0131] [Example 18: Rubbed FFS-type liquid crystal display element] 1. Preparation of Liquid Crystal Alignment Agent The solution of the polymer (PAA-14) obtained in Synthesis Example 14 was diluted with NMP and butyl cellosolve (BC) to obtain a solution with a solvent composition of NMP / BC=80 / 20 (mass ratio) and a solid content of 3.5 mass %. This solution was filtered through a filter with a pore size of 0.2 μm to prepare a liquid crystal alignment agent (AL-25).

[0132] 2. Fabrication of FFS-type LCD elements using the rubbing method A glass substrate (referred to as the first substrate) with a flat electrode (bottom electrode), an insulating layer, and a comb-shaped electrode (top electrode) laminated in this order on one side thereof, and a glass substrate (referred to as the second substrate) without an electrode, were prepared. Next, a liquid crystal alignment agent (AL-25) was applied to the electrode-formed surface of the first substrate and one side of the second substrate using a spinner and heated (pre-baked) on a hot plate at 110°C for 3 minutes. This was followed by drying (post-baking) for 30 minutes in a nitrogen-purged oven at 230°C to form a coating film with an average thickness of 0.08 μm. The coating film surface was then rubbed using a rubbing machine equipped with a roll wrapped around a rayon cloth at a roll rotation speed of 1000 rpm, a stage movement speed of 3 cm / sec, and a pile depth of 0.3 mm. This was followed by ultrasonic cleaning in ultrapure water for 1 minute and then drying in a clean oven at 100°C for 10 minutes to obtain a pair of substrates with liquid crystal alignment films. Next, a pair of substrates with liquid crystal alignment films were screen-printed with an epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres, leaving a liquid crystal injection port at the edge of the surface where the liquid crystal alignment film was formed. The substrates were then stacked and pressed together, and the adhesive was thermally cured at 150°C for 1 hour. Next, negative liquid crystal (MLC-6608, manufactured by Merck) was injected into the gap between the pair of substrates through the liquid crystal injection port, and the liquid crystal injection port was then sealed with an epoxy adhesive. To eliminate flow alignment during liquid crystal injection, the substrates were heated to 120°C and then slowly cooled to room temperature to produce a liquid crystal cell. When stacking the pair of substrates, the rubbing directions of each substrate were antiparallel.

[0133] 3. Evaluation The liquid crystal cells manufactured in 2 above were evaluated for liquid crystal alignment, alignment uniformity, and VHR reliability in the same manner as in Example 1. In addition, the liquid crystal alignment agent (AL-25) was used to evaluate adhesion in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0134] [Examples 19 to 37 and Comparative Examples 8 to 11] A liquid crystal alignment agent was prepared in the same manner as in Example 18, except that the composition of the liquid crystal alignment agent was changed as shown in Table 4. Furthermore, using the obtained liquid crystal alignment agent, an FFS-type liquid crystal cell was produced by a rubbing method in the same manner as in Example 18, and various evaluations were carried out. The results are shown in Table 4. In Examples 28 to 30 and Comparative Example 10, two types of polymers were used as the polymer component. In Table 4, the numerical values ​​in the polymer column represent the blending ratio (parts by mass) of the solid content of each polymer relative to 100 parts by mass of the total amount of the polymer components used in preparing the liquid crystal alignment agent.

[0135] [Table 4]

[0136] As shown in Table 4, Examples 18 to 37, which used a liquid crystal alignment agent containing the polymer [A] having the partial structure (a), showed better results in alignment uniformity and VHR reliability than Comparative Examples 8 to 11, which used a liquid crystal alignment agent not containing the polymer [A]. Furthermore, Examples 18, 21, 23, and 27 to 30 also showed good liquid crystal alignment properties and adhesion to the substrate.

[0137] In Comparative Example 11, although a naphthalene ring structure (naphthalene-1,4-diyl group) was introduced into the polymer by using compound (DB-23) as part of the diamine compound, the liquid crystal alignment was "poor (×)" and the alignment uniformity was "fair (△)".

[0138] [Example 38: PSA type liquid crystal display element] 1. Preparation of Liquid Crystal Alignment Agent A solution containing 5 parts by mass of the polymer (PSQ-1) obtained in Synthesis Example 52 and a solution containing 95 parts by mass of the polymer (PI-7) obtained in Synthesis Example 46 were mixed and diluted with NMP and BC to obtain a solution with a solvent composition of NMP / BC=50 / 50 (mass ratio) and a solids concentration of 3.5% by mass. This solution was filtered through a filter with a pore size of 0.2 μm to prepare a liquid crystal aligning agent (AL-49).

[0139] 2. Preparation of Liquid Crystal Composition 5% by mass of a liquid crystal compound represented by the following formula (L1-1) and 0.3% by mass of a photopolymerizable compound represented by the following formula (L2-1) were added to 10 g of nematic liquid crystal (MLC-6608, manufactured by Merck) and mixed to obtain liquid crystal composition LC1. [ka]

[0140] 3. Manufacturing of PSA type liquid crystal display elements The liquid crystal alignment agent (AL-49) prepared above was applied to the transparent electrode surface of a glass substrate with an ITO transparent electrode using a spinner. The substrate was prebaked on a hot plate at 80°C for 1 minute, and then heated in a nitrogen-purged oven at 200°C for 1 hour to remove the solvent, forming a 0.08 μm-thick coating (liquid crystal alignment film). This coating film was then rubbed using a rubbing machine equipped with a roll wrapped around a rayon cloth at a roll rotation speed of 400 rpm, a stage movement speed of 3 cm / sec, and a pile depth of 0.1 mm. The substrate was then ultrasonically cleaned in ultrapure water for 1 minute and then dried in a clean oven at 100°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. This process was repeated to obtain a pair (two substrates) with a liquid crystal alignment film. Note that this rubbing treatment was weak, intended to suppress liquid crystal collapse and facilitate alignment division. An epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was applied by screen printing to the outer periphery of the surface of one of the substrates bearing the liquid crystal alignment film, and then the liquid crystal alignment film surfaces of the pair of substrates were placed facing each other, overlapped, and pressed together, followed by heating at 150°C for 1 hour to thermally cure the adhesive. Next, liquid crystal composition LC1 was filled into the gap between the substrates through the liquid crystal injection port, which was then sealed with an epoxy adhesive. To prevent flow alignment during liquid crystal injection, the resulting mixture was heated at 150°C for 10 minutes and then slowly cooled to room temperature. Next, an AC voltage of 10 V at a frequency of 60 Hz was applied between the electrodes of the obtained liquid crystal cell, and while the liquid crystal was in a driving state, ultraviolet rays of 50,000 J / m were irradiated using an ultraviolet irradiation device that used a metal halide lamp as a light source. 2The irradiation amount was measured using an actinometer measuring at a wavelength of 365 nm as a reference. A PSA liquid crystal cell was thus produced.

[0141] 4. Evaluation The liquid crystal cells produced in 3 above were evaluated for liquid crystal alignment, alignment uniformity, VHR reliability, and adhesion in the same manner as in Example 1. Table 5 shows the evaluation results.

[0142] [Examples 39 to 41 and Comparative Examples 12 and 13] A liquid crystal alignment agent was prepared in the same manner as in Example 38, except that the composition of the liquid crystal alignment agent was changed as shown in Table 5. In addition, a PSA-type liquid crystal cell was produced using the obtained liquid crystal alignment agent in the same manner as in Example 38, and various evaluations were performed. The evaluation results are shown in Table 5. In Table 5, the numerical values ​​in the polymer column represent the blending ratio (parts by mass) of the solid content of each polymer relative to 100 parts by mass of the total amount of the polymer components used in preparing the liquid crystal alignment agent.

[0143] [Table 5]

[0144] As shown in Table 5, Examples 38 to 41, which used a liquid crystal alignment agent containing polymer [A], were all rated as good in alignment uniformity, VHR reliability, and adhesion. Among these, Example 38, which used a liquid crystal alignment agent containing polymer (PI-7) having a naphthalene ring structure in the partial structure (a), was also rated as good in liquid crystal alignment. In contrast, Comparative Examples 12 and 13, which used a liquid crystal alignment agent not containing polymer [A], were rated as "fair (△)" for alignment uniformity and "poor (×)" for VHR reliability, and Comparative Example 13 was also rated as "poor (×)" for adhesion.

[0145] [Example 42: Optical VA type liquid crystal display element] 1. Preparation of Liquid Crystal Alignment Agent A solution containing 30 parts by mass of the polymer (MI-1) obtained in Synthesis Example 53 and 70 parts by mass of the polymer (PAA-14) obtained in Synthesis Example 14 was mixed and diluted with NMP and BC to obtain a solution with a solvent composition of NMP / BC = 80 / 20 (mass ratio) and a solids concentration of 3.5 mass%. This solution was filtered through a filter with a pore size of 0.2 μm to prepare a liquid crystal aligning agent (AL-55).

[0146] 2. Fabrication of VA-type LCD elements using the photoalignment method The liquid crystal alignment agent (AL-55) prepared above was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a spinner, and pre-baked on a hot plate at 80°C for 1 minute. It was then heated at 230°C for 1 hour in an oven with the interior replaced with nitrogen, forming a coating film with a thickness of 0.1 μm. Next, the surface of this coating film was irradiated with polarized ultraviolet light at 1,000 J / m², including a 313 nm emission line, using an Hg-Xe lamp and a Glan-Taylor prism. 2 The substrate was irradiated with light from a direction tilted by 40° from the normal to the substrate to impart liquid crystal alignment ability. The same procedure was repeated to prepare a pair (two substrates) having a liquid crystal alignment film. An epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was screen-printed onto the outer periphery of the surface of one of the substrates bearing the liquid crystal alignment film. The pair of substrates were then placed with the liquid crystal alignment film surfaces facing each other and pressed together so that the UV light axes of the substrates were antiparallel to each other. The adhesive was then thermally cured at 150°C for 1 hour. Next, negative liquid crystal (MLC-6608, manufactured by Merck) was injected into the gap between the substrates through the liquid crystal injection port, which was then sealed with an epoxy adhesive. To eliminate flow alignment during liquid crystal injection, the substrate was heated to 130°C and then slowly cooled to room temperature.

[0147] 3. Evaluation The liquid crystal cells produced in 2 above were evaluated for liquid crystal alignment, alignment uniformity, VHR reliability, and adhesion in the same manner as in Example 1. Table 6 shows the evaluation results.

[0148] [Comparative Example 14] A liquid crystal alignment agent was prepared in the same manner as in Example 42, except that the composition of the liquid crystal alignment agent was changed as shown in Table 6. In addition, an optical VA-type liquid crystal cell was produced using the obtained liquid crystal alignment agent in the same manner as in Example 42, and various evaluations were performed. The results are shown in Table 6. In Table 6, the numerical values ​​in the polymer column represent the blending ratio (parts by mass) of the solid content of each polymer relative to 100 parts by mass of the total amount of the polymer components used in preparing the liquid crystal alignment agent.

[0149] [Table 6]

[0150] As shown in Table 6, Example 42, which used a liquid crystal alignment agent containing polymer [A], was evaluated as good in liquid crystal alignment, alignment uniformity, VHR reliability, and adhesion. In contrast, Comparative Example 14, which used a liquid crystal alignment agent not containing polymer [A], was evaluated as "fair (△)" in alignment uniformity and "poor (×)" in VHR reliability.

[0151] From the above results, it was revealed that a liquid crystal alignment agent containing a polymer [A] having a partial structure (a) can be used to obtain liquid crystal elements with excellent liquid crystal alignment properties, alignment uniformity, and VHR reliability, and can also form a liquid crystal alignment film with excellent adhesion to the substrate.

Claims

1. A liquid crystal aligning agent comprising a polymer [A] having a partial structure (a) represented by the following formula (1) (excluding the partial structure represented by the following formula (DA-6E)) in its main chain: 【Chemistry 1】 (In formula (1), An １ X is a divalent group having a substituted or unsubstituted fused ring structure comprising a plurality of aromatic monocyclic rings, and is obtained by removing one hydrogen atom each from two different rings among the plurality of aromatic monocyclic rings constituting the fused ring, or by removing one hydrogen atom each from two different rings among the plurality of aromatic monocyclic rings contained in a substituent of the fused ring structure. １ and X ２ are each independently a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms, or a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms in which some methylene groups are -O-, -S-, or -NR １ -, -C(=O)-, -NR １ —C(═O)— or —NR １ —C(═O)—NR ２ - is a divalent group substituted with -. １ An to which １ and an aromatic monocyclic ring in X ２ An to which １ It is different from the aromatic monocyclic ring in R. １ and R ２ are each independently a hydrogen atom or a monovalent organic group. １ and Ar ２ are each independently a divalent aromatic ring group. "*" represents a bond. 【Chemistry 4】 (In formula (DA-6E), "*" represents a bond.)

2. The liquid crystal aligning agent according to claim 1 , wherein the polymer [A] contains a structural unit derived from a diamine having the partial structure (a).

3. The X １ and X ２ or both of which are —O—, —S—, —NR １ - or -C(=O)-, and the An １ The liquid crystal aligning agent according to claim 1, wherein the aromatic ring is bonded to the aromatic ring.

4. The liquid crystal aligning agent according to claim 1 , wherein the polymer [A] is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

5. The An １ The liquid crystal aligning agent according to claim 1, wherein is represented by the following formula (an-1-1), formula (an-1-2), formula (an-1-3) or formula (an-1-4): 【Chemistry 2】 (In formula (an-1-1), formula (an-1-2), formula (an-1-3) and formula (an-1-4), Y １ ~Y ６ are each independently an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogenated alkoxy group having 1 to 5 carbon atoms, an alkoxyalkyl group having 1 to 5 carbon atoms, an alkoxyalkoxyalkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydroxyl group. r1 to r4 are each independently an integer of 0 to 6. r5 and r6 are each independently an integer of 0 to 4. X ４ is -C(R ６ ) (R ７ )-, -O-, -S-, -NR ８ -or-SO ２ - is. R ６ and R ７ R are each independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. ８ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a thermally detachable group. １ " is X in formula (1) １ and X ２ represents a bond with one of the two, and "* ２ " indicates a bond with the other atom.)

6. The An １ The liquid crystal aligning agent according to claim 1, wherein is a substituted or unsubstituted naphthalene-2,6-diyl group or naphthalene-3,7-diyl group.

7. A partial structure represented by the above formula (1) (wherein X 1 and X 2 in formula (1) each independently represent -S-, -NR 1 -, -C(═O)-, -NR 1 -C(═O)-, -NR 1 -C(═O)-NR 2 -, a substituted or unsubstituted alkanediyl group having 1 to 18 carbon atoms, or a divalent group in which some methylene groups in a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms are replaced by -O-, -S-, -NR 1 -, -C(═O)-, -NR 1 -C(═O)- or -NR 1 -C(═O)-NR 2 - (wherein when An 1 has a fluorene structure, X 1 and X 2 in formula (1) are simultaneously -NR 1 -, and when An 1 The liquid crystal aligning agent according to claim 1, further comprising a polymer [B] having no —NR 1 —C(═O)— in the main chain, except that when X 1 and X 2 in formula (1) have a carbazole structure, —NR 1 —C(═O)— in the main chain.

8. The liquid crystal aligning agent according to claim 7, wherein the polymer [B] is at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and addition polymer.

9. A liquid crystal alignment film formed by the liquid crystal aligning agent according to any one of claims 1 to 8.

10. A liquid crystal device comprising the liquid crystal alignment film according to claim 9 .

11. A polymer which is a polyamic acid, a polyamic acid ester, or a polyimide and has a partial structure represented by the following formula (1) (excluding the partial structure represented by the following formula (DA-6E)) in its main chain. 【Transformation 3】 (In formula (1), An １ X is a divalent group having a substituted or unsubstituted fused ring structure comprising a plurality of aromatic monocyclic rings, and is obtained by removing one hydrogen atom each from two different rings among the plurality of aromatic monocyclic rings constituting the fused ring, or by removing one hydrogen atom each from two different rings among the plurality of aromatic monocyclic rings contained in a substituent of the fused ring structure. １ and X ２ are each independently a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms, or a substituted or unsubstituted alkanediyl group having 2 to 18 carbon atoms in which some methylene groups are -O-, -S-, or -NR １ -, -C(=O)-, -NR １ —C(═O)— or —NR １ —C(═O)—NR ２ - is a divalent group substituted with -. １ An to which １ and an aromatic monocyclic ring in X ２ An to which １ It is different from the aromatic monocyclic ring in R. １ and R ２ are each independently a hydrogen atom or a monovalent organic group. １ and Ar ２ are each independently a divalent aromatic ring group. "*" represents a bond. 【Transformation 5】 (In formula (DA-6E), "*" represents a bond.)

Images