JP2010117684A - Liquid crystal aligning agent, liquid crystal alignment layer and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent, capable of giving a liquid crystal alignment layer which shows excellent liquid crystal alignment restraining force (pretilt angle developing property) and has improved burn-in property and high reliability, and on which the accumulation of residual DC voltage after long-term application of thermal stress is suppressed. <P>SOLUTION: The liquid crystal aligning agent contains a polymer, having a specific repeating unit typified by a structure represented by formula (1-1) and at least one polymer selected from a polyamic acid obtained, by mamking a tetracarboxylic acid dianhydride react with a diamine and an imidized polymer thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element. More specifically, a liquid crystal aligning agent that provides a liquid crystal alignment film that exhibits excellent liquid crystal alignment regulating power (pretilt angle expression), has a high voltage holding ratio and reliability, and has suppressed seizure after long-term thermal stress application, The present invention relates to a liquid crystal alignment film formed from a liquid crystal alignment agent and a liquid crystal display element containing the liquid crystal alignment film.

Since LCD calculators were mass-produced for the first time, liquid crystal display devices have been developed from the viewpoint of space saving and low power consumption, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, personal digital assistants, digital cameras, Applications in various fields such as mobile phones and various monitors are advancing, and active development is continuing.
As the liquid crystal display element, a nematic liquid crystal is used, and a TN (twisted nematic) type liquid crystal display element or TN type in which the major axis of liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other substrate. STN (Super Twisted Nematic) type liquid crystal display elements that have a higher contrast than liquid crystal display elements have been widely used. In order to further improve the display quality of the liquid crystal display, a VA (Vertical Alignment) type liquid crystal display element having a small viewing angle dependency, an IPS (In Plane Switching) type liquid crystal display element, a small viewing angle dependency and a high-speed video screen. Optically compensated bend (Optical Compensated Birefringence = OCB) type liquid crystal display elements having excellent responsiveness have been developed.

In a liquid crystal display element, a liquid crystal alignment film is used to control the alignment of liquid crystal molecules. A liquid crystal alignment film is generally formed by applying a so-called “rubbing process” in which a liquid crystal aligning agent containing an organic resin is applied to a substrate, then the solvent is removed to form a coating film, and the coating film is rubbed in a certain direction. Has been. Since the liquid crystal alignment film is a member in direct contact with the liquid crystal molecules, it is known that the electrical characteristics of the liquid crystal alignment film have a very large influence on the image sticking (charge accumulation) and voltage holding ratio of the liquid crystal panel. Therefore, it is expected to improve the seizure resistance of the liquid crystal panel by improving the liquid crystal alignment film. For example, Patent Documents 1 and 2 propose a technique for facilitating diffusion of accumulated charges (reducing the afterimage erasing time) by changing the composition of the liquid crystal alignment film.
In recent years, liquid crystal display elements have come to be applied to high-quality monitors, and development of liquid crystal television applications in particular has been active. In addition to the vividness of the display screen and high response speed, the liquid crystal display element used for the liquid crystal television application is required to have long-term durability comparable to that of a cathode ray tube television. Such long-term durability is unthinkable from the mode of use of conventional liquid crystal display elements, and the techniques described in Patent Documents 1 and 2 also apply thermal stress over a long period at a level required for television applications. Later improvement of seizure is not assumed.
JP 2003-295194 A JP 2004-94179 A JP 2002-327058 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544

The present invention has been made based on the above circumstances, and its purpose is to exhibit excellent liquid crystal alignment regulating power (pretilt angle expression), improved image sticking characteristics, and high reliability. And a liquid crystal alignment agent capable of providing a liquid crystal alignment film in which the accumulation of residual DC voltage after application of thermal stress over a long period of time is suppressed, a liquid crystal alignment film having the above characteristics, and a liquid crystal excellent in seizure resistance after long-term thermal stress It is to provide a display element.
Other objects and advantages of the present invention will become apparent from the following description.

In accordance with the present invention, the above objects and advantages of the present invention are primarily as follows:
Following formula (1)

(In the formula (1), R ^I is a hydrogen atom or a methyl group, A ¹ is a single bond, a methylene group, an alkylene group having 2 to 10 carbon atoms, or the following formula (2)

(In Formula (2), n is an integer of 5-150.)
In the case where A ¹ is a single bond, a methylene group or an alkylene group having 2 to 10 carbon atoms, B ¹ is a fluoroalkyl group having 1 to 10 carbon atoms, and A 1 ^{When 1} is a divalent group represented by the above formula (2), B ¹ is an alkyl group having 1 to 10 carbon atoms or a fluoroalkyl group having 1 to 10 carbon atoms. )
A polymer having a repeating unit represented by:
This is achieved by a liquid crystal aligning agent containing a polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and at least one polymer selected from the group consisting of imidized polymers thereof.
The above objects and advantages of the present invention are, secondly,
Achieved by a liquid crystal alignment film formed from the above liquid crystal aligning agent,
This is achieved by a liquid crystal display device comprising the above liquid crystal alignment film.

  According to the present invention, it exhibits excellent liquid crystal alignment regulating power (pretilt angle expression), has improved seizure characteristics, and has high reliability, particularly accumulation of residual DC voltage after long-term thermal stress application. A liquid crystal aligning agent capable of providing a suppressed liquid crystal aligning film, a liquid crystal aligning film having the above characteristics, and a liquid crystal display element excellent in seizure resistance after long-term thermal stress are provided.

Hereinafter, the present invention will be described in detail.
The liquid crystal aligning agent of this invention reacts the polymer (henceforth "polymer (1)") which has a repeating unit represented by the said Formula (1), tetracarboxylic dianhydride, and diamine. It contains at least one polymer selected from the group consisting of the resulting polyamic acid and its imidized polymer.
In the divalent group represented by the above formula (2) of A ¹ in the above formula (1), n is an integer of 5 to 150, and this value is preferably 7 to 15.
Examples of the fluoroalkyl group having 1 to 10 carbon atoms of B ¹ in the above formula (1) include a trifluoromethyl group, 1,1,2,2-tetrafluoroethyl group, 1,1,2,2,2- A pentafluoroethyl group, a perfluoro-5-methylhexyl group, a perfluorooctyl group, a perfluorodecyl group, a 2- (perfluorooctyl) ethyl group, and the like can be given.
Specific examples of the repeating unit represented by the above formula (1) include, for example, the following formulas (1-1) to (1-10):

(In formulas (1-5) and (1-10), n has the same meaning as in formula (2) above.)
The repeating unit represented by each of these can be mentioned. Among these, the repeating unit represented by the above formula (1-6) is preferable in that a liquid crystal alignment film having particularly excellent electrical characteristics can be provided.
In addition to the repeating unit represented by the above formula (1), the polymer (1) is further represented by the following formula (3):

(In Formula (3), R ^II is a hydrogen atom or a methyl group, A ² is a single bond, a methylene group or an alkylene group having 2 to 10 carbon atoms, and B ² is a cyclic ether structure having 2 to 10 carbon atoms. A group having
A repeating unit represented by the following formula (4):

(In Formula (4), R ^III is a hydrogen atom or a methyl group, A ³ is a single bond, a phenylene group, or the following formulas (A ³ -1) to (A ³ -6).

_{^{- (CH 2) k -O- *}} (A 3 -5)
_{^{- (CH 2) m -COO- *}} (A 3 -6)
(I in the above formula is 0 or 2, respectively, j is 0 or 1, respectively, k and m are each an integer of 1 to 6, and "*" bond marked with indicates that binds to B ^3.)
B ³ is a monovalent organic group having 17 to 30 carbon atoms having a steroid skeleton, an alkylcyclohexyl group having an alkyl group having 4 to 8 carbon atoms, or 3 carbon atoms. -30 alkyl groups, difluorophenyl groups, trifluoromethylphenyl groups or trifluoromethoxyphenyl groups. )
A repeating unit represented by the following formula (5):

(In Formula (5), R ^IV is a hydrogen atom, a methyl group or a carboxymethyl group, B ⁴ is a hydrogen atom, a methyl group or a carboxyl group, provided that when R ^IV is a carboxymethyl group, B ⁴ is It is not a carboxyl group.)
A repeating unit represented by the following formula (6):

(In the formula (6), A ⁵ is a divalent group comprising a single bond, or an oxygen atom or a sulfur atom, or an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom, B ⁵ is 6 carbon atoms 30 aryl groups or alicyclic groups having 4 to 10 carbon atoms.)
A repeating unit represented by formula (7):

(In the formula (7), R ^V is a hydrogen atom or a methyl group, A ⁶ is a single bond, an oxygen atom or a sulfur atom, or a divalent atom containing an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. B ⁶ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms.)
And a repeating unit represented by the following formula (8)

(In Formula (8), R ^VI is a hydrogen atom or a methyl group, A ⁷ is a single bond or —COO— ^* (where “*” indicates that the bond attached thereto is bonded to B ^7. And B ⁷ is an alkylene group having 2 to 10 carbon atoms, an arylene group having 6 to 30 carbon atoms, or a divalent alicyclic group having 4 to 10 carbon atoms.)
It may have at least one repeating unit selected from the group consisting of repeating units represented by:
The cyclic ether structure contained in the repeating unit represented by the above formula (3) is subjected to a thermal crosslinking reaction by applying a liquid crystal aligning agent of the present invention to form a coating film, followed by heat treatment (post-baking), Thereby, the heat resistance, liquid crystal resistance (solvent resistance) and film density of the liquid crystal alignment film obtained can be further improved, and the diffusion of impurity ions contained in the liquid crystal into the liquid crystal alignment film can be further reduced. Due to these effects, even if thermal stress is applied to the resulting liquid crystal display element or the liquid crystal panel is driven for a long period of time, the problem of the decrease in voltage holding ratio and burn-in can be solved more reliably. A liquid crystal aligning agent that provides an alignment film can be obtained. In addition, the liquid crystal orientation can be further improved by the repeating unit represented by the above formula (4). For these reasons, the polymer (1) preferably has a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (3) and a repeating unit represented by (4).

Therefore, as the cyclic ether structure having 2 to 10 carbon atoms of B ² in the formula (3), a 1,2-epoxy structure or a 1,3-epoxy structure having thermal crosslinking reactivity is preferable, and the reactivity is excellent. And a 1,2-epoxy structure is more preferable. As the repeating unit represented by the above formula (3), in the above formula (3), A ² is a methylene group or an alkylene group having 2 to 10 carbon atoms, and B ² is a group having a 1,2-epoxy structure. A certain repeating unit is preferable, and a repeating unit in which A ² is a methylene group or an alkylene group having 2 or 5 carbon atoms and B ² is a group having a 1,2-epoxy structure is more preferable.
The repeating unit represented by the above formula (4) can be contained in the polymer (1) in order to improve the liquid crystal alignment properties of the obtained liquid crystal alignment film and further electrical properties. B ³ in the above formula (4) is a monovalent organic group having 17 to 30 carbon atoms having a steroid skeleton, an alkylcyclohexyl group having an alkyl group having 4 to 8 carbon atoms, an alkyl group having 3 to 30 carbon atoms, Examples thereof include a difluorophenyl group, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and the like, and in particular, an alkyl having a steroid skeleton having 17 to 30 carbon atoms or an alkyl group having 4 to 8 carbon atoms. A cyclohexyl group is preferred. Here, examples of the monovalent organic group having 17 to 30 carbon atoms having a steroid skeleton include a cholestane-3-yl group, a cholesta-5-en-3-yl group, and a cholesta-24-en-3-yl group. And cholesta-5,24-dien-3-yl group, lanostane-3-yl group, and the like.

The repeating unit represented by the above formula (5) improves the compatibility between the polymer (1) and at least one polymer selected from the group consisting of polyamic acid and its imidized polymer. When the compound (1) has a repeating unit represented by the above formula (3), it can be included in the polymer (1) for the purpose of promoting the crosslinking reaction of the cyclic ether structure.
The repeating unit represented by the above formula (6) and the repeating unit represented by the above formula (7) are each included in the polymer (1) in order to further improve the heat resistance of the obtained liquid crystal alignment film. Can do.
A ⁵ in the above formula (6) is preferably a single bond. Examples of the aryl group having 6 to 30 carbon atoms of B ⁵ in the formula (6) include, for example, a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, etc .; For example, a cyclopentyl group, a cyclohexyl group, etc. can be mentioned, respectively, and especially a phenyl group or a cyclohexyl group is preferable.
A ⁶ in the above formula (7) is preferably a single bond. Examples of the alkyl group having 1 to 20 carbon atoms of B ⁶ in the above formula (7) include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, and n-to. Examples of the aryl group having 6 to 30 carbon atoms include a phenyl group, a 4-biphenyl group, a 2-biphenyl group, a 1-naphthalenyl group, and a 2-naphthalenyl group. Of these, a phenyl group is preferred.
The repeating unit represented by the above formula (8) is for the purpose of improving the compatibility between the polymer (1) and at least one polymer selected from the group consisting of polyamic acid and imidized polymer thereof. It can be included in the polymer (1).
Examples of the alkylene group having 2 to 10 carbon atoms of B ⁷ in the formula (8) include an ethylene group and a 1,4-butylene group; and examples of the arylene group having 6 to 30 carbon atoms include a phenylene group; Examples of the divalent alicyclic group having 4 to 10 carbon atoms include a cyclohexane-1,4-diyl group.

The content ratio of the repeating unit represented by the above formula (1) in the polymer (1) is preferably 1% by weight or more based on the total weight of the polymer (1), and more preferably 1 to 50%. % By weight, more preferably 1 to 30% by weight, and particularly preferably 1 to 20% by weight. By setting the content ratio of the repeating unit represented by the above formula (1) within this range, good electrical characteristics can be imparted to the obtained liquid crystal alignment film.
The content of the repeating unit represented by the above formula (3) is preferably 50% by weight or less, more preferably 5 to 50% by weight, based on the total weight of the polymer (1). Preferably it is 15 to 45 weight%, and it is especially preferable that it is 20 to 40 weight%. By setting the content ratio of the repeating unit represented by the above formula (3) within this range, the film density of the obtained liquid crystal alignment film can be further improved, whereby the liquid crystal alignment of impurity ions contained in the liquid crystal Diffusion into the film can be further reduced, and image sticking of the liquid crystal display element can be further suppressed.
The content ratio of the repeating unit represented by the above formula (4) is preferably 60% by weight or less, more preferably 1 to 60% by weight, further preferably based on the total weight of the polymer (1). Is 2 to 40% by weight, and preferably 3 to 30% by weight. By setting the content ratio of the repeating unit represented by the above formula (4) within this range, it is possible to impart good pretilt angle developability to the obtained liquid crystal alignment film.
The content ratio of the repeating unit represented by the above formula (5) is preferably 50% by weight or less, more preferably 1 to 50% by weight, further preferably based on the total weight of the polymer (1). Is 1 to 45% by weight, particularly preferably 1 to 40% by weight.
The content ratio of the repeating unit represented by the above formula (6) is preferably 20% by weight or less, more preferably 1 to 20% by weight, further preferably based on the total weight of the polymer (1). Is 1 to 10% by weight.
The content ratio of the repeating unit represented by the formula (7) is preferably 20% by weight or less, more preferably 1 to 20% by weight, and still more preferably based on the total weight of the polymer (1). Is 1 to 10% by weight.
The content ratio of the repeating unit represented by the above formula (8) is preferably 50% by weight or less, more preferably 1 to 50% by weight, further preferably, based on the total weight of the polymer (1). Is 1 to 45% by weight, particularly preferably 1 to 40% by weight.

The polystyrene-converted weight average molecular weight (hereinafter referred to as “Mw”) measured using gel permeation chromatography (GPC) for the polymer (1) is preferably 2 × 10 ³ to 1 × 10 ⁶ , more preferably. Is 5 × 10 ^{3 to} 5 × 10 ⁵ , particularly preferably 1 × 10 ⁴ to 4 × 10 ⁵ . If the Mw is less than 2 × 10 ³ , panel characteristics may be deteriorated due to elution of low molecular components (causing a decrease in voltage holding ratio or panel seizure). On the other hand, when it exceeds 1 × 10 ⁶ , the solution viscosity of the obtained liquid crystal aligning agent becomes too high, which may cause a problem in coating properties. The molecular weight distribution (hereinafter referred to as “Mw / Mn”. Mn is the number average molecular weight in terms of polystyrene measured using GPC) is preferably 20.0 or less, more preferably 15.0 or less. Especially preferably, it is 10.0 or less. By reducing Mw / Mn, it becomes easy to obtain a liquid crystal aligning agent that has excellent coating properties and does not cause the problem of deterioration in panel characteristics due to elution of the low molecular components described above.
The polymer (1) as described above is, for example, the following formula (1 ′)

(In formula (1 ′), R ^I , A ¹ and B ¹ have the same meanings as in formula (1)).
(Hereinafter referred to as “monomer (1 ′)”) or monomer (1 ′) and the following formula (3 ′)

(In the formula (3 ′), R ^II , A ² and B ² have the same meanings as in the above formula (3).)
(Hereinafter referred to as “monomer (3 ′)”), the following formula (4 ′)

(In formula (4 ′), R ^III , A ³ and B ³ each have the same meaning as in formula (4) above.)
(Hereinafter referred to as “monomer (4 ′)”), the following formula (5 ′)

(In the formula (5 ′), R ^IV and B ⁴ have the same meanings as in the above formula (5).)
(Hereinafter referred to as “monomer (5 ′)”), the following formula (6 ′)

(In formula (6 ′), A ⁵ and B ⁵ have the same meanings as in formula (6) above.)
(Hereinafter referred to as “monomer (6 ′)”), the following formula (7 ′)

(In the formula (7 ′), R ^V , A ⁶ and B ⁶ have the same meaning as in the above formula (7).)
(Hereinafter referred to as “monomer (7 ′)”) and the following formula (8 ′)

（上式中、ｐは繰り返し単位数であり、好ましくは７〜１５の整数である。）
で表される二価の基である。
単量体（３’）は、上記式（３）で表される繰り返し単位を導く単量体であり、その具体例としては、例えばアクリル酸グリシジル、メタクリル酸グリシジル、アクリル酸−３，４−エポキシブチル、メタクリル酸−３，４−エポキシブチル、アクリル酸−６，７−エポキシヘプチル、メタクリル酸−６，７−エポキシヘプチル、α−エチルアクリル酸−６，７−エポキシヘプチルなどを挙げることができる。これらのうち、得られる液晶配向膜の膜密度が高く、優れた電気特性、電気特性の信頼性を発現しうる点で、アクリル酸グリシジルまたはメタクリル酸グリシジルが好ましい。 (In the formula (8 ′), R ^VI , A ⁷ and B ⁷ have the same meanings as in the above formula (8).)
And at least one selected from the group consisting of compounds represented by the following (hereinafter referred to as “monomer (8 ′)”), preferably in a suitable solvent in the presence of a suitable polymerization initiator. Can be synthesized.
The monomer (1 ′) is a monomer that leads to the repeating unit represented by the above formula (1). Preferable specific examples of the monomer (1 ′) include, for example, acrylic acid-2,2,2-trifluoroethyl, acrylic acid-3,3,4,4-tetrafluorobutyl, acrylic acid-3,3, 4,4,4-pentafluorobutyl, 2- (perfluorooctyl) ethyl acrylate, acrylic acid (trifluoromethyl) polydimethylsiloxane, acrylic acid (perfluorooethyl) polydimethylsiloxane, acrylic acid (perfluoro) Octyl) polydimethylsiloxane, 2,2,2-trifluoroethyl methacrylate, 3,4,4-tetrafluorobutyl methacrylate, 3,3,4,4,4-pentafluorobutyl methacrylate , Methacrylic acid-2- (perfluorooctyl) ethyl, Methacrylic acid (trifluoromethyl) polydimethylsilo Mention may be made of xylene, methacrylic acid (perfluorooctyl) polydimethylsiloxane, methacrylic acid (perfluorooctyl) polydimethylsiloxane. Of these, acrylic acid-2,2,2-trifluoroethyl, acrylic acid (trifluoromethyl) polydimethylsiloxane, and methacrylic acid-2,2,2-trifluoroethyl are preferred in that they can exhibit excellent electrical characteristics. And methacrylic acid (trifluoromethyl) polydimethylsiloxane. "Polydimethylsiloxane" in the above compound means the following formula

(In the above formula, p is the number of repeating units, preferably an integer of 7 to 15.)
It is a bivalent group represented by these.
The monomer (3 ′) is a monomer that leads to the repeating unit represented by the above formula (3), and specific examples thereof include, for example, glycidyl acrylate, glycidyl methacrylate, acrylic acid-3,4- Examples include epoxybutyl, methacrylic acid-3,4-epoxybutyl, acrylic acid-6,7-epoxyheptyl, methacrylic acid-6,7-epoxyheptyl, and α-ethylacrylic acid-6,7-epoxyheptyl. it can. Among these, glycidyl acrylate or glycidyl methacrylate is preferable in that the obtained liquid crystal alignment film has a high film density and can exhibit excellent electrical characteristics and reliability of electrical characteristics.

The monomer (4 ′) is a monomer that leads to a repeating unit represented by the above formula (4).
Specific examples of the monomer (4 ′) include cholestanyl methacrylate, 4- (4′-pentylbicyclohexyl-4-yl) phenyl methacrylate, and tocopherol methacrylate. Such a monomer (4 ′) can be obtained, for example, by reacting a halogenated (meth) acryloyl with the compound B ¹ -A ¹ -OH according to a known esterification reaction.
The monomer (5 ′) is a monomer that leads to the repeating unit represented by the above formula (5). Specific examples thereof include maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, Examples include acrylic acid, methacrylic acid, and crotonic acid. Among these, the compatibility between the polymer (1) and the polyamic acid and its imidized polymer is good, and the obtained liquid crystal alignment film has a high film density and exhibits high reliability in electrical characteristics and electrical characteristics. Acrylic acid or methacrylic acid is preferred.
The monomer (6 ′) is a monomer that leads to the repeating unit represented by the above formula (6). Specific examples thereof include N-phenylmaleimide, N-naphthylmaleimide, and N-anthracenylmaleimide. , N-fluorenylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide and the like. Among these, N-phenylmaleimide or N-cyclohexylmaleimide is preferable.
The monomer (7 ′) is a monomer that leads to the repeating unit represented by the above formula (7), and specific examples thereof include, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, Examples include α-olefins such as 1-heptene, 1-octene, 1-nonene, 1-decene, and styrene, 4-vinylbiphenyl, 2-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, α-methylstyrene, etc. Of these, styrene is preferred.
The monomer (8 ′) is a monomer that leads to the repeating unit represented by the above formula (8), and specific examples thereof include, for example, isopropenylphenol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, Examples thereof include 4-hydroxybutyl acrylate and 1,4-cyclohexanedimethanol monoacrylate.

The use ratio (copolymerization ratio) of the monomers (1 ′) to (8 ′) in synthesizing the polymer (1) can be appropriately set depending on the composition of the desired polymer (1).
Therefore, the copolymerization ratio of the monomer (1 ′) is preferably 1% by weight or more based on the total weight of the monomers, more preferably 1 to 50% by weight, and even more preferably 1 -30% by weight, particularly preferably 1-20% by weight.
The copolymerization ratio of the monomer (3 ′) is preferably 50% by weight or less, more preferably 5 to 50% by weight, and further preferably 15 to 45% based on the total weight of the monomers. % By weight, particularly preferably 20 to 40% by weight.
The copolymerization ratio of the monomer (4 ′) is preferably 60% by weight or less, more preferably 1 to 60% by weight, and further preferably 2 to 40% by weight based on the total weight of the monomers. %, Particularly preferably 3 to 30% by weight.
The copolymerization ratio of the monomer (5 ′) is preferably 50% by weight or less, more preferably 1 to 50% by weight, and further preferably 1 to 45% by weight based on the total weight of the monomers. %, Particularly preferably 1 to 40% by weight.
The copolymerization ratio of the monomer (6 ′) is preferably 20% by weight or less, more preferably 1 to 20% by weight, and further preferably 1 to 10% by weight based on the total weight of the monomers. %.
The copolymerization ratio of the monomer (7 ′) is preferably 20% by weight or less, more preferably 1 to 20% by weight, and further preferably 1 to 10% by weight based on the total weight of the monomers. %.
The copolymerization ratio of the monomer (8 ′) is preferably 50% by weight or less, more preferably 1 to 50% by weight, and further preferably 1 to 45% by weight based on the total weight of the monomers. %, Particularly preferably 1 to 40% by weight.

Examples of the solvent used for the synthesis of the polymer (1) include alcohol, ether, glycol ether, ethylene glycol alkyl ether acetate, diethylene glycol alkyl ether, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, propylene glycol alkyl ether propio. Nates, aromatic hydrocarbons, ketones, esters and the like.
Specific examples thereof include alcohols such as methanol, ethanol, benzyl alcohol, 2-phenylethyl alcohol, and 3-phenyl-1-propanol;
Tetrahydrofuran, di-n-amyl ether, etc. as ether; Glycol ether, eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc .; Ethylene glycol alkyl ether acetate, eg, methyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether acetate , Ethylene glycol monoethyl ether acetate, etc .;
Diethylene glycol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether and the like; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol mono Propyl ether, propylene glycol monobutyl ether, etc .;
As propylene glycol alkyl ether propionate, for example, propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, propylene glycol butyl ether propionate, etc .;
Examples of propylene glycol alkyl ether acetates include propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate;
Aromatic hydrocarbons such as toluene, xylene, etc .;
Examples of ketones include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diisobutyl ketone and the like;

Examples of esters include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, hydroxy Ethyl acetate, hydroxybutyl acetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, 2-hydroxy -3-methylbutanoate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, propoxy Methyl acetate, ethyl propoxyacetate, propyl propoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propyl butoxyacetate, butylbutoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, 2-methoxypropionic acid Propyl, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl 2-butoxypropionate Propyl 2-butoxypropionate, butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, 3-methoxypropyl Butyl pionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl 3-propoxypropionate, 3-propoxypropionate Examples thereof include propyl acid, butyl 3-propoxypropionate, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, butyl 3-butoxypropionate, and the like.

Of these, ethylene glycol alkyl ether acetate, diethylene glycol alkyl ether, propylene glycol monoalkyl ether, and propylene glycol alkyl ether acetate are preferable. Particularly, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol. Methyl ether acetate or methyl 3-methoxypropionate is preferred.
As the polymerization initiator used for the synthesis of the polymer (1), those generally known as radical polymerization initiators can be used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile) Azo compounds such as; benzoyl peroxide, lauroyl peroxide, t-butyl peroxypivalate, organic peroxides such as 1,1′-bis- (t-butylperoxy) cyclohexane; and hydrogen peroxide. When a peroxide is used as the radical polymerization initiator, the peroxide may be used together with a reducing agent to form a redox initiator.
In the synthesis of the polymer (1), a molecular weight modifier can be used to adjust the molecular weight of the polymer (1). Specific examples thereof include halogenated hydrocarbons such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan and thioglycolic acid; dimethylxanthogen sulfide, Xanthogens such as diisopropylxanthogen disulfide; terpinolene, α-methylstyrene dimer and the like.

In the synthesis of the polymer (1), the polymerization conditions (solvent species, charge ratio of solvent and monomer, polymerization temperature, initiator species and amount added, type of molecular weight modifier and amount added, etc.) are appropriately selected. It is preferable to control the molecular weight range by adjusting. Appropriate polymerization conditions for realizing the above molecular weight range can be easily estimated by a person skilled in the art by performing a few preliminary experiments.
A polymer solution containing the polymer (1) is obtained as described above. This polymer solution may be used as it is for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after the polymer (1) contained in the polymer solution is isolated or isolated. You may use for preparation of a liquid crystal aligning agent, after refine | purifying a polymer (1). The polymer (1) is isolated by pouring the polymer solution into a large amount of a poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or distilling the polymer solution under reduced pressure using an evaporator. It can be done by a method. Further, the polymer (1) can be obtained by dissolving the isolated polymer (1) again in an organic solvent and then precipitating with a poor solvent, or by performing the step of evaporating under reduced pressure with an evaporator once or several times. Can be purified.

<Polyamic acid>
The polyamic acid in this invention can be obtained by making tetracarboxylic dianhydride and diamine react.
[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4- Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclo Ntylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b -Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 5-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -7-methyl-5- (tetrahydro-2,5 -Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5- (tetrahydro-2, 5-Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2 , 5-Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- ] -Furan-1,3-dione, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2] -oct -7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-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-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, Formulas (TI) and (T-II)

(In formulas (TI) and (T-II), R ¹ and R ³ are each a divalent organic group having an aromatic ring, and R ² and R ⁴ are each a hydrogen atom or an alkyl group. And a plurality of R ² and R ⁴ may be the same or different.)
An aliphatic or alicyclic tetracarboxylic dianhydride such as a compound represented by each of the following:
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2 , 2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis ( Triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate) Retate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), the following formulas (T-1) to (T-3)

And aromatic tetracarboxylic dianhydrides such as compounds represented by each of the above. These may be used alone or in combination of two or more.
Among tetracarboxylic dianhydrides used in the synthesis of polyamic acid, among the above, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl- 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3 , 3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4 , 5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4 , 5,9b- Xahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2] -oct -7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-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-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, pyro Mellitic dianhydride 3,3 ', 4,4'-benzofu Non-tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 2,3 ′, 2,3′-biphenyltetracarboxylic dianhydride, 1,4,5 , 8-Naphthalenetetracarboxylic dianhydride, among the compounds represented by the above formula (TI), the following formulas (T-4) to (T-6)

And the following formula (T-7) among the compounds represented by formula (T-II):

The viewpoint that it is possible to develop good liquid crystal alignment, including at least one selected from the group consisting of compounds represented by (hereinafter referred to as “specific tetracarboxylic dianhydride (1)”). To preferred. Particularly preferred specific tetracarboxylic dianhydrides (1) are 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl- 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-Dioxotetra Dro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, It is at least one selected from the group consisting of 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone and pyromellitic dianhydride.
The tetracarboxylic dianhydride used for the synthesis of polyamic acid should contain 30 mol% or more of the specific tetracarboxylic dianhydride (1) as described above with respect to the total tetracarboxylic dianhydride. Preferably, it contains 50 mol% or more.

  Examples of the diamine used for the synthesis of the polyamic acid include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4 , 4′-diaminodiphenylsulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2 '-Dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 3,3'-ditri Fluoromethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophen ) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl ] Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4 Aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′- Bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoro) Romechiru) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] - aromatic diamines such as octafluoro biphenyl;

2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-di (4-aminophenyl) -benzidine, the following formula (DI)

(In the formula (DI), R ⁵ is a monovalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ is a divalent organic group. R ⁶ is an alkyl group having 1 to 4 carbon atoms, and a1 is an integer of 0 to 3.)
A compound represented by formula (D-II):

(In formula (D-II), R ⁷ is a divalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² is A plurality of X ² may be the same or different, R ⁸ is an alkyl group having 1 to 4 carbon atoms, and a2 is an integer of 0 to 4 respectively. .)
A diamine having two primary amino groups and a nitrogen atom other than the primary amino group in the molecule, such as a compound represented by:
1,3-bis (aminomethyl) cyclohexane, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 1,4-diaminocyclohexane, isophorone Diamine, Tetrahydrodicyclopentadienylenediamine, Hexahydro-4,7-methanoindanylene methylene diamine, Tricyclo [6.2.1.0 ^2,7 ] -Undecylenedimethyl diamine, 4,4'-methylene bis (cyclohexyl) An aliphatic or cycloaliphatic diamine;
The following formula (D-III)

(In Formula (D-III), R ⁹ is a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁹ may be the same or different, and s is 1 to 3 respectively. And t is an integer of 1 to 20.)
And diaminoorganosiloxanes such as compounds represented by the formula: These diamines may be used alone or in combination of two or more.
The benzene ring of the aromatic diamine may be substituted with one or two or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group). R ⁶ and R ⁸ in the above formulas (DI) and (D-II) are each preferably a methyl group, and a1 and a2 are each preferably 0 or 1, and are preferably 0 It is more preferable.
Among the above-mentioned diamines used for the synthesis of the polyamic acid in the present invention, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7 -Diaminofluorene, 4,4'-diaminodiphenyl ether, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4 -(4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4- Aminophenoxy) biphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4 4′-diamino-2,2′-dimethylbiphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, represented by the above formula (DI) Of the compounds to be produced, the following formula (D-1)

Of the compounds represented by formula (D-II), the following formula (D-2)

Of the compound represented by the formula 1,3-bis (aminomethyl) cyclohexane, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), and the compound represented by the above formula (D-III) The following formula (D-3)

3,3 ′-(tetramethyldisiloxane-1,3-diyl) bis (propylamine), 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3 , 6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole and at least one selected from the group consisting of N, N′-di (4-aminophenyl) -benzidine (hereinafter referred to as “specific diamine”). Is preferred.
Particularly preferred specific diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 4,4′-diamino-2,2′-dimethylbiphenyl and It is at least one selected from the group consisting of 1,3-bis (aminomethyl) cyclohexane.
As the diamine used for the synthesis of the polyamic acid, the specific diamine as described above is preferably contained in an amount of 1 mol% or more, more preferably 10 mol% or more, based on the total diamine.

The liquid crystal aligning agent of this invention expresses a desired pretilt angle by adjusting the composition of said polymer (1) and the content rate of the polymer (1) in a liquid crystal aligning agent to an appropriate range. However, when the liquid crystal aligning agent of the present invention is used in a TN type, STN type, OCB type or VA type liquid crystal display element, it is used for the synthesis of polyamic acid contained in the liquid crystal aligning agent or an imidized polymer thereof. It is also possible to control the pretilt angle of the obtained liquid crystal alignment film by using a diamine having a pretilt angle-expressing site as the diamine to be used.
Examples of the diamine having such a pretilt angle expression site include the following formula (D-IV):

(In Formula (D-IV), R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a methyl group, R ¹² is a linear or branched alkyl group having 1 to 20 carbon atoms, R ¹³ and R ¹⁴ are each independently a divalent organic group.)
A compound represented by the following formula (D-V)

(In the formula (D-V), R ¹⁵ represents an oxygen atom, a sulfur atom, —CO—, —COO—, —OCO—, —NHCO—, —CONH— or a methylene group, and R ¹⁶ represents a cholestanyl skeleton or cholestenyl. A monovalent group having a skeleton, a monovalent group having a trifluoromethylphenyl group or a trifluoromethoxyphenyl group, or an alkyl group having 1 to 22 carbon atoms, and R ¹⁷ is an alkyl group having 1 to 4 carbon atoms. , A3 is an integer of 0-3.)
The compound etc. which are represented by these can be mentioned. These diamine compounds having a pretilt angle-expressing site are used singly or in combination of two or more.
As the monovalent group having a cholestanyl skeleton or cholestenyl skeleton of R ^{16 in} the above formula (D-V), those having 17 to 30 carbon atoms are preferable, and examples thereof include a 3-cholestanyl group and a 3-cholestenyl group. it can. R ¹⁷ is preferably a methyl group, and a3 is preferably 0 or 1, more preferably 0.
Specific examples of the compound represented by the above formula (D-IV) include, for example, the following formulas (D-4) and (D-5):

Specific examples of the compound represented by the above formula (D-V) include, for example, the following formulas (D-6) to (D-10):

The compounds represented by each of the above can be mentioned.
When the liquid crystal aligning agent of the present invention is used for a VA type liquid crystal display element, the liquid crystal aligning agent exhibits excellent vertical alignment properties of liquid crystal. It is preferable to use the compound represented, It is more preferable to use at least 1 type selected from the compounds represented by each of said formula (D-6)-(D-10), and especially said formula ( It is preferable to use at least one of the compound represented by D-6) and the compound represented by the above formula (D-7).
The ratio of the diamine having a pretilt angle-expressing site is preferably 8 to 60 mol%, more preferably 9 to 50 mol%, and particularly preferably 10 to 40 mol%, based on the total diamine. In this case, the diamine having a pretilt angle expression site and the above-mentioned specific diamine may be used in combination, and the use ratio of the above-mentioned specific diamine in such a case is preferably 1 to 90 mol% with respect to the total diamine. Preferably it is 10-90 mol%.

[Synthesis of polyamic acid]
The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 with respect to 1 equivalent of the amino group contained in the diamine. The ratio which becomes -2 equivalent is preferable, More preferably, it is the ratio which becomes 0.3-1.2 equivalent.
The polyamic acid synthesis reaction is preferably carried out in an organic solvent under a temperature condition of preferably -20 to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 100 hours, more preferably 1 to 50 hours.
The organic solvent that can be used here is not particularly limited as long as it can dissolve the produced polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide And aprotic polar solvents such as dimethyl sulfoxide, γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight based on the total amount (a + b) of the reaction solution. It is preferable that Here, when the organic solvent is used in combination with the poor solvent described below, the amount of the organic solvent used (a) should be understood as meaning the total amount of the organic solvent and the poor solvent. is there.

For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, etc., which are generally believed to be poor solvents for polyamic acid, may be used in combination as long as the resulting polyamic acid does not precipitate. it can. Specific examples of the poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene Glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n- Chill ether, 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, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1 , 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, diisopentyl ether and the like.
When using the poor solvent as described above together with the organic solvent, the use ratio of the poor solvent can be appropriately set within a range in which the generated polyamic acid does not precipitate, but is preferably 70% by weight or less with respect to the total solvent. More preferably, it is 50% by weight or less.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. Polyamic acid can be isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling the reaction solution under reduced pressure using an evaporator. it can. The polyamic acid can be purified by a method of dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent, or a method of performing the step of evaporating under reduced pressure with an evaporator once or several times.

<Imidized polymer>
The imidized polymer of polyamic acid in the present invention can be obtained by dehydrating and ring-closing the polyamic acid obtained as described above. The imidized polymer referred to here is a concept including a partially imidized product obtained by partially imidizing the polyamic acid and a completely imidized product obtained by imidizing 100%. It is called "union".
[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for the synthesis of the imidized polymer include the same compounds as the tetracarboxylic dianhydride used for the synthesis of the polyamic acid described above.
The tetracarboxylic dianhydride used for the synthesis of the imidized polymer contained in the liquid crystal aligning agent of the present invention is selected from the group consisting of alicyclic tetracarboxylic dianhydrides and pyromellitic dianhydrides. A tetracarboxylic dianhydride containing at least one (hereinafter referred to as “specific tetracarboxylic dianhydride (2)”) is preferred.
Particularly preferred specific tetracarboxylic dianhydrides (2) are 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5 -Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5 -Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-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-carboxy Ruborunan -2: 3,5: selected from 6-dianhydride and 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10- tetraone group consisting Is at least one kind.
The tetracarboxylic dianhydride used in the synthesis of the imidized polymer contains the specific tetracarboxylic dianhydride (2) in an amount of 30 mol% or more based on the total tetracarboxylic dianhydride. It is preferable that the content is 50 mol% or more.
[Diamine]
Examples of the diamine used for the synthesis of the imidized polymer include the same diamine as that used for the synthesis of the polyamic acid described above.

[Method for synthesizing imidized polymer]
The dehydration ring closure reaction of polyamic acid can be carried out by (i) heating the polyamic acid or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring closure catalyst to this solution, and heating if necessary. It is done by the method to do.
The reaction temperature in the method (i) of heating the polyamic acid is preferably 50 to 300 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 300 ° C., the molecular weight of the imidized polymer obtained may decrease. The reaction time is preferably 2 to 24 hours, more preferably 3 to 10 hours.
On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of amic acid structures of a polyamic acid. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. And the reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC, Reaction time becomes like this. Preferably it is 2-8 hours, More preferably, it is 3-6 hours.

  The imidized polymer obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained imidized polymer. . On the other hand, in the method (ii), a reaction solution containing an imidized polymer is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. After separating, it may be used for preparing a liquid crystal aligning agent, or the isolated imidized polymer may be purified and then used for preparing a liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. Isolation and purification of the imidized polymer can be performed by performing the same operations as described above as the method for isolating and purifying the polyamic acid.

-Imidization rate of imidized polymer-
The imidation ratio in the imidized polymer used in the present invention is preferably 10 to 99%, more preferably 20 to 99%, and particularly preferably 45 to 99%. Here, the “imidization rate” is a numerical value representing the ratio of the number of imide ring structures as a percentage of the total number of amic acid structures and the number of imide ring structures in the imidized polymer. At this time, what is part of the imide ring is an isoimide ring is also included in the number of imide ring structures. Such imidization ratio, the imidized polymer, after preferably sufficiently dried, dissolved in a suitable deuterated solvent (e.g. deuterated dimethyl sulfoxide), at room temperature with tetramethylsilane as a reference substance ¹ H- It can obtain | require by the following numerical formula (A) from the result of having measured NMR.

Imidization rate (%) = (1-A ¹ / A ² × α) × 100 (A)

A ¹ : Peak area derived from protons of NH group appearing in the vicinity of 10 ppm A ² : Peak area derived from other protons α: Other protons relative to one proton of NH group in the precursor (polyamic acid) of imidized polymer Number ratio

-End-modified polymer-
The polyamic acid and the imidized polymer contained in the liquid crystal aligning agent of the present invention may each be a terminal-modified type having a controlled molecular weight. By using the terminal-modified polymer, the coating properties of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention. Such a terminal-modified polymer can be obtained by adding a molecular weight modifier to a polymerization reaction system when synthesizing a polyamic acid. Examples of molecular weight regulators include acid monoanhydrides, monoamine compounds, monoisocyanate compounds, and the like.
Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n -Hexadecyl succinic acid anhydride etc. can be mentioned. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. it can. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
In the case of acid monoanhydride, the molecular weight regulator is used in the ratio of all tetracarboxylic dianhydrides used for synthesizing polyamic acid, and in the case of monoamine compound, the total amount used for synthesizing polyamic acid. In the case of a monoisocyanate compound with respect to diamine, it is preferably 5 mol% or less, more preferably 2 mol% or less, respectively, based on the total tetracarboxylic dianhydride used when synthesizing a polyamic acid. .

-Solution viscosity-
The polyamic acid or its imidized polymer obtained as described above preferably has a solution viscosity of 500 to 10,000 mPa · s when it is made into a solution having a concentration of 20% by weight. More preferably, it has a solution viscosity of ˜7,000 mPa · s.
The solution viscosity (mPa · s) of the above polymer is E for a polymer solution having a concentration of 20% by weight prepared using a good solvent for the polymer (for example, N-methyl-2-pyrrolidone, γ-butyrolactone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.
[Use ratio of polyamic acid and imidized polymer]
The use ratio of at least one polymer selected from the group consisting of polyamic acid and imidized polymer in the liquid crystal aligning agent of the present invention is the weight (W ¹ ) of the polymer (1) in the liquid crystal aligning agent and the polyamic acid. And the ratio to the total weight (W ² ) of the imidized polymer is preferably such that W ¹ : W ² = 1: 99 to 90:10, and W ¹ : W ² = 2: 98 to 80 : 20, preferably W ¹ : W ² = 3: 97 to 60:40.

<Other additives>
The liquid crystal alignment film of the present invention contains, as an essential component, at least one selected from the group consisting of the polymer (1) and polyamic acid and the imidized polymer thereof as described above. You may contain. Examples of such other components include functional silane compounds and low molecular compounds having two or more epoxy groups in the molecule (hereinafter referred to as “epoxy compounds”). These functional silane compounds or epoxy compounds can be added to the liquid crystal aligning agent of the present invention in order to further improve the adhesion and electrical properties of the obtained liquid crystal aligning film to the substrate surface.
Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4 7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N- Benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, 3-glycid Examples include xylpropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, and N-bis (oxyethylene) -3-aminopropyltriethoxysilane. When these functional silane compounds are used, the use ratio is preferably based on 100 parts by weight of the total of the polymers (the total of the polymer (1), the polyamic acid and the imidized polymer; the same applies hereinafter). Is 1 to 50 parts by weight, more preferably 2 to 40 parts by weight, particularly preferably 3 to 20 parts by weight.

  The epoxy compound is distinguished from the case where the polymer (1) has a cyclic ether structure. Specifically, the epoxy compound has a molecular weight of less than 2,000. Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′— Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4, 4 ′ Diaminodiphenylmethane, N, N, N ', N'- tetraglycidyl -p- phenylenediamine, N, N-diglycidyl - benzylamine, N, N-diglycidyl - such as aminomethyl cyclohexane may be mentioned as preferred. When using these epoxy compounds, the use ratio is preferably 1 to 50 parts by weight, more preferably 1 to 30 parts by weight, and particularly preferably 1 to 20 parts by weight with respect to a total of 100 parts by weight of the polymer. is there.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention comprises at least one selected from the group consisting of the polymer (1), polyamic acid and its imidized polymer as described above, and other additives optionally blended as necessary. Preferably, it is dissolved and contained in an organic solvent.
As an organic solvent which can be used for the liquid crystal aligning agent of this invention, the same thing as the solvent illustrated as what is used for the synthesis reaction of a polymer (1) can be mentioned.
Particularly preferable organic solvents used in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethyl from the viewpoint of printability. Acetamide, 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, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethyl Examples include lenglycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, isoamyl propionate, isoamyl isobutyrate, and diisopentyl ether. These can be used alone or in admixture of two or more.

A particularly preferable solvent composition in the liquid crystal aligning agent of the present invention is a composition obtained by combining the above-mentioned solvents, in which a solid component does not precipitate in the liquid crystal aligning agent, and the surface tension of the liquid crystal aligning agent is 25 to 40 mN / The composition is in the range of m.
The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is selected in consideration of viscosity, volatility, etc., preferably 1 -50% by weight, more preferably 2-40% by weight, still more preferably 3-30% by weight. That is, the liquid crystal aligning agent of the present invention forms a coating film that becomes a liquid crystal aligning film by applying this to the substrate surface and removing the solvent, but when the solid content concentration is less than 1% by weight, In some cases, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 50% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics. In some cases, a liquid crystal alignment film having excellent internal uniformity cannot be obtained.
Note that the particularly preferable range of the solid content concentration differs depending on the coating method used when the liquid crystal aligning agent is applied to the substrate, and more specifically, it is appropriate for the liquid crystal aligning agent to have an appropriate solution viscosity for each coating method. It is preferable to adjust to a certain solid content concentration. For example, when the spinner method is used, the solution viscosity of the liquid crystal aligning agent is preferably adjusted to a range of 3.0 to 10.0 mPa · s. When using the printing method, it is preferable to adjust the solution viscosity of the liquid crystal aligning agent to a range of 12 to 50 mPa · s. In the case of the ink jet method, the solution viscosity of the liquid crystal aligning agent is preferably in the range of 3 to 15 mPa · s.
The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 0 to 200 ° C, more preferably 20 to 60 ° C.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following method.
(1) First, the liquid crystal alignment film of the present invention is applied onto a pair of substrates, and the solvent is removed to form a coating film. Here, when the display mode of the liquid crystal display element to be manufactured is a vertical electric field system such as a TN type, an STN type, or a VA type, two substrates on which a transparent conductive film patterned on one side is provided. Are used as a pair of substrates. On the other hand, when the display mode of the liquid crystal display element to be manufactured is a horizontal electric field method, a pair of a substrate provided with a transparent conductive film having a comb-like pattern and a substrate not having a transparent conductive film are paired. Used as a substrate.
In any of the above cases, the liquid crystal aligning agent is applied on the substrate (on the surface having the transparent conductive film of the substrate when the substrate has a transparent conductive film). As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (alicyclic olefin) can be used. Examples of the transparent conductive film provided on one surface of the substrate include an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), and the like. Can be used. Moreover, in order to obtain these patterned transparent conductive films, a method of forming a pattern by a photo-etching method after forming a transparent conductive film without a pattern, and a mask having a desired pattern when forming the transparent conductive film For example, a method of directly forming a patterned transparent conductive film can be employed.
The liquid crystal aligning agent is applied onto the substrate by an appropriate application method such as a roll coater method, a spinner method, a printing method, or an ink jet method. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound, or the like is applied in advance to the coated surface of the substrate. You may keep it.

After application, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied alignment agent. The pre-bake temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.5 to 10 minutes, more preferably 0.5 to 5 minutes. Thereafter, a baking (post-baking) step is performed for the purpose of completely removing the solvent. This Portobake is intended to completely remove the solvent from the coating film, and the polymer (1) contained in the liquid crystal aligning agent of the present invention has a cyclic ether structure represented by the above formula (2). When it has a repeating unit, it can also be performed for the purpose of promoting the thermal crosslinking reaction of the cyclic ether structure. The post-baking temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 180 minutes, more preferably 10 to 120 minutes.
Thus, the coating film used as a liquid crystal aligning film can be formed. The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.
When the liquid crystal display element to which the liquid crystal aligning agent of the present invention is applied is a VA liquid crystal display element, for example, a projecting building as described in Patent Document 3 (Japanese Patent Laid-Open No. 2002-327058) is used. After forming on a substrate, a liquid crystal aligning agent may be applied to improve viewing angle characteristics.

(2) When the display mode of the liquid crystal display element to be manufactured is VA type, the coating film formed as described above can be used as a liquid crystal alignment film as it is. The rubbing process described may be performed. On the other hand, when the display mode of the liquid crystal display element to be manufactured is a vertical electric field method other than the VA type and a horizontal electric field method, a rubbing process is performed on the formed coating film surface.
The rubbing treatment can be performed by a method of rubbing in a certain direction with a roll around which a cloth made of fibers such as nylon, rayon, and cotton is wound. Thereby, the orientation ability of liquid crystal molecules is imparted to the coating film to form a liquid crystal orientation film. Furthermore, a part of the liquid crystal alignment film as shown in, for example, Patent Document 4 (Japanese Patent Laid-Open No. 6-222366) or Patent Document 5 (Japanese Patent Laid-Open No. 6-281937) is applied to the coating film after the rubbing treatment. Or a part of the surface of the liquid crystal alignment film as shown in Patent Document 6 (Japanese Patent Laid-Open No. 5-107544) By forming a resist film on the substrate and performing a rubbing treatment in a direction different from the previous rubbing treatment, and then removing the resist film, so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region, It is possible to improve the visibility characteristics of the obtained liquid crystal display element.

(3) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates opposed to each other. Here, when the rubbing process is performed on the coating film, the two substrates are disposed to face each other so that the rubbing directions in the respective coating films are at a predetermined angle, for example, orthogonal or antiparallel.
In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped on the liquid crystal alignment film surface. The other substrate is bonded so as to face each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, whereby a liquid crystal cell can be manufactured.
Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase, and then gradually cooled to room temperature, so that the liquid alignment at the time of filling the liquid crystal is achieved. It is desirable to remove.
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell.

Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.
As the liquid crystal, for example, nematic liquid crystal, smectic liquid crystal, or the like can be used, and among these, nematic liquid crystal is preferable. In the case of a VA liquid crystal cell, a nematic liquid crystal having negative dielectric anisotropy is preferable. For example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, and phenylcyclohexane liquid crystal are used. It is done. In the case of a TN type liquid crystal cell or an STN type liquid crystal cell, a nematic type liquid crystal having positive dielectric anisotropy is preferable. For example, biphenyl type liquid crystal, phenyl cyclohexane type liquid crystal, ester type liquid crystal, terphenyl type liquid crystal, biphenyl cyclohexane type A liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubane liquid crystal, or the like is used. These liquid crystals include, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck); p Ferroelectric liquid crystals such as -decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be further added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Measurement of the solution viscosity, weight average molecular weight and molecular weight distribution of the polymers in Examples and Comparative Examples, production of liquid crystal display elements, and evaluation of vertical alignment, voltage holding ratio and seizure resistance of the liquid crystal display elements were performed by the following methods. It was.
[Measurement of solution viscosity]
The solution viscosity (mPa · s) of the polymer was measured at 25 ° C. using an E-type rotational viscometer for the polymer solution shown in each synthesis example.
[Measurement of weight average molecular weight and molecular weight distribution]
The weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene were measured using gel permeation chromatography (GPC) under the following conditions to obtain the value of molecular weight distribution (Mw / Mn).
GPC measuring device: “HLC-8020” manufactured by Tosoh Corporation
Column: Columns “TSK guardcolumn α”, “TSK gel α-M” and “TSK gel α-2500” manufactured by Tosoh Corporation are used in series. Solvent: Lithium bromide / one for 3 L of dimethylformamide A solution in which 9.4 g of hydrate and 1.7 g of phosphoric acid are dissolved Measurement temperature: 35 ° C.

[Manufacture of liquid crystal display elements]
The liquid crystal aligning agent prepared in each example or comparative example was applied on a transparent conductive film made of an ITO film provided on one surface of a glass substrate using a spinner, prebaked at 80 ° C. for 1 minute on a hot plate, and then cleaned in an oven A substrate having a film thickness of 60 nm on the transparent conductive film was obtained by post-baking at 200 ° C. for 1 hour in a nitrogen atmosphere. The substrate is rubbed once with a rubbing machine having a roll around which a rayon cloth is wound, with a roll rotation speed of 400 rpm, a stage moving speed of 30 mm / sec, and a hair foot pushing length of 0.4 mm. A liquid crystal alignment ability was imparted. Next, the substrate was ultrasonically cleaned in pure water for 1 minute, and then dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film. These operations were repeated to prepare a pair (two) of substrates having a liquid crystal alignment film.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the surfaces having the liquid crystal alignment film of the substrate having the pair of liquid crystal alignment films, the liquid crystal alignment film surfaces face each other. The adhesive was cured by overlapping and pressing.
Next, after filling negative liquid crystal (MLC-2038, manufactured by Merck & Co., Inc.) into the gap between the substrates through the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and polarizing plates are formed on both sides of the substrate. Was bonded to produce a liquid crystal display element (vertical alignment type liquid crystal display element).

[Evaluation of vertical alignment]
With respect to the vertical alignment type liquid crystal display device manufactured as described above, the pretilt angle was measured by an anchoring strength measuring device “OMS-J3” manufactured by Chuo Seiki Co., Ltd. When the pretilt angle is 87 ° or more, the vertical alignment is “good”, and when it is less than 87 °, the vertical alignment is “bad”.
[Evaluation of voltage holding ratio]
The liquid crystal display device manufactured as described above was applied with a voltage of 5 V at 60 ° C. with an application time of 60 microseconds and a span of 1,670 milliseconds, and then held for 1,670 milliseconds after release of the application. The rate was measured under an atmosphere of 60 ° C. The measuring device of voltage holding ratio used VHR-1 made by Toyo Corporation. The voltage holding ratio is “good” if the value of the voltage holding ratio is 97.5% or more, and “bad” if it is less than 97.5%.
[Reliability test of liquid crystal display elements (presence of display defects)]
In a high temperature and high humidity environment (temperature: 70 ° C., relative humidity: 80%), the liquid crystal display element is driven with a rectangular wave of 5 V, 60 Hz, and the presence or absence of white spot-like display defects after 1,500 hours has passed with a microscope. Observed. As a result, the case where there was no white spot-like display defect was evaluated as reliability “good”, and the case where there was a white spot-like display defect was evaluated as reliability “bad”.
[Evaluation of seizure resistance (measurement of residual DC voltage, acceleration test)]
The liquid crystal display device manufactured as described above was applied with a DC voltage of 17 V in an atmosphere of 100 ° C. for 20 hours, then the application of the voltage was released, and the liquid crystal cell was left to stand in a room temperature environment for 15 minutes. The residual voltage (residual DC voltage) was determined by the flicker elimination method. It can be judged that the smaller the value of the residual DC voltage is, the liquid crystal display element is excellent in long-term seizure resistance. A liquid crystal display element having a residual DC voltage value of 200 mV or less has “good” seizure resistance. When the residual DC voltage value is larger than 200 mV, it can be said that seizure resistance is “bad”.

Synthesis Example 1 (Synthesis of Compound (4 ′))
After dissolving 800 g of β-cholestanol in 8,000 mL of dehydrated tetrahydrofuran (THF) and adding 270 g of triethylamine, 360 g of methacryloyl chloride was gradually added dropwise and stirred at room temperature for 3 hours to carry out the reaction. After completion of the reaction, triethylamine hydrochloride was removed by filtration, THF was removed by distillation under reduced pressure, and then 4,000 mL of chloroform was added. The resulting solution was washed with water and the organic layer was dried over magnesium sulfate, and then chloroform was removed by distillation under reduced pressure. Thereafter, recrystallization with ethanol was performed to obtain 540 g of cholestanyl methacrylate as a white solid (yield: 57.4%).
Synthesis Example 2 (Synthesis of polymer (1) (1))
In a four-necked flask equipped with a stir bar, three-way cock and thermometer, 10.0 g (0.0595 mol) of methacrylic acid-2,2,2-trifluoroethyl was used as a monomer. Methacrylate 30.0 g (0.0657 mol), glycidyl methacrylate 25.0 g (0.176 mol), methacrylic acid 10.0 g (0.116 mol), styrene 2.50 g (0.0240 mol), N-cyclohexylmaleimide 2.50 g (0.0139 mol) and 2-hydroxyethyl methacrylate 20.0 g (0.154 mol) were charged, diethylene glycol ethyl methyl ether 200 g as a solvent, and 2,2′-azobis (2 , 4-dimethylvaleronitrile) 4.50 g and α as a molecular weight regulator It was added methylstyrene dimer 2.00 g. This was bubbled with a nitrogen stream for about 10 minutes to replace the nitrogen in the system, and then reacted at 70 ° C. for 5 hours in a nitrogen atmosphere to contain 33.2% by weight of the polymer (1-1). A solution was obtained. When the molecular weight of the polymer (1-1) was measured by GPC, Mw = 21,000 and Mw / Mn = 2.3, and no peak attributable to the residual monomer was observed.
Synthesis Example 3 (Synthesis of polymer (1) (2))
In a four-necked flask equipped with a stir bar, a three-way cock and a thermometer, 5.00 g (0.00940 mol) of ethyl 2- (perfluorooctyl) methacrylate as a monomer was used as a monomer. Cholestanyl methacrylate obtained in Synthesis Example 1 above. 30.0 g (0.0657 mol), glycidyl methacrylate 25.0 g (0.176 mol), methacrylic acid 10.0 g (0.116 mol), styrene 2.50 g (0.0240 mol), N-cyclohexylmaleimide 2 .50 g (0.0139 mol) and 2-hydroxyethyl methacrylate 25.0 g (0.192 mol) were charged, 200 g of diethylene glycol ethyl methyl ether as a solvent, and 2,2′-azobis (2,2) as a polymerization initiator. 4-dimethylvaleronitrile) 4.50 g and a molecular weight regulator Then, 2.00 g of α-methylstyrene dimer was added. This was bubbled in a nitrogen stream for about 10 minutes to replace the nitrogen in the system, and then reacted at 70 ° C. for 5 hours in a nitrogen atmosphere to contain 33.5% by weight of the polymer (1-2). A solution was obtained. When the molecular weight of the polymer (1-2) was measured by GPC, Mw = 16,000 and Mw / Mn = 2.0, and no peak attributable to the residual monomer was observed.

Synthesis Example 4 (Synthesis of imidized polymer (1))
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.40 mol) of p-phenylenediamine as diamine and the above formula (D-6) 52 g (0.10 mol) of the compound represented was dissolved in 830 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.
Next, 1,900 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP (in this operation, pyridine and acetic anhydride used for the dehydration cyclization reaction were removed from the system. The same applies hereinafter), whereby the imidation rate was reduced. About 1,200 g of a solution containing 15% by weight of 50% imidized polymer (PI-1) was obtained. A small amount of this solution was taken, NMP was added, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 47 mPa · s.
Synthesis Example 5 (Synthesis of imidized polymer (2))
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 38 g (0.35 mol) of p-phenylenediamine as diamine, 20 g of 4,4′-diaminodiphenylmethane (0.10 mol) and 26 g (0.050 mol) of the compound represented by the above formula (D-6) were dissolved in 800 g of NMP and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.
Next, 1,800 g of NMP was added to the obtained polyamic acid solution, 80 g of pyridine and 100 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 1,100 g of a solution containing 15% by weight of an imidized polymer (PI-2) having an imidization ratio of about 80%. Obtained. A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 87 mPa · s.

Synthesis Example 6 (Synthesis of imidized polymer (3))
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.40 mol) of p-phenylenediamine as diamine and the above formula (D-7) 49 g (0.10 mol) of the compound represented was dissolved in 820 g of NMP and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.
Next, 1,910 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP to obtain about 1,200 g of a solution containing 15% by weight of an imidized polymer (PI-3) having an imidization ratio of about 50%. . A small amount of this solution was taken, NMP was added, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 47 mPa · s.
Synthesis Example 7 (Synthesis of imidized polymer (4))
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 49 g (0.45 mol) of p-phenylenediamine as diamine and the above formula (D-7) 25 g (0.050 mol) of the represented compound was dissolved in 740 g of NMP and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.
Next, 1,720 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP to obtain about 1,200 g of a solution containing 15% by weight of an imidized polymer (PI-4) having an imidization ratio of about 50%. . A small amount of this solution was taken, NMP was added, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 47 mPa · s.

Synthesis Example 8 (Synthesis of imidized polymer (5))
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 49 g (0.45 mol) of p-phenylenediamine as diamine and the above formula (D-7) 25 g (0.050 mol) of the represented compound was dissolved in 740 g of NMP and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.
Next, 1,720 g of NMP was added to the obtained polyamic acid solution, 59 g of pyridine and 77 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain about 1,200 g of a solution containing 15% by weight of an imidized polymer (PI-5) having an imidization ratio of about 65%. . A small amount of this solution was collected, and NMP was added thereto, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 67 mPa · s.
Comparative Synthesis Example 1 (Synthesis of Comparative Polymer)
In a four-necked flask equipped with a stirrer, a three-way cock and a thermometer, 40 g (0.28 mol) of glycidyl methacrylate, 20 g (0.23 mol) of methacrylic acid, 20 g of styrene (0.19 mol) and 20 g (0.11 mol) of N-cyclohexylmaleimide was charged, 200 g of diethylene glycol ethyl methyl ether as a solvent, 4.5 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as an initiator, and α as a molecular weight regulator. -2.0 g of methylstyrene dimer was added. This was bubbled with a nitrogen stream for about 10 minutes to replace the nitrogen in the system, and then reacted at 70 ° C. for 5 hours in a nitrogen atmosphere to contain 33% by weight of the comparative polymer (R-1). A polymer solution was obtained.
When the molecular weight of the polymer (R-1) was measured by GPC, Mw = 22,000 and Mw / Mn = 2.4, and no peak attributable to the residual monomer was observed.

Example 1
A solution containing the polymer (1-1) obtained in Synthesis Example 2 and a solution containing the imidized polymer (PI-1) obtained in Synthesis Example 4 were combined with the polymer (1-1 ): The imidized polymer (PI-1) was mixed so that the weight ratio was 5:95, and N-methyl-2-pyrrolidone (NMP) and butyl cellosolve were added thereto, and the solvent composition was NMP: butyl cellosolve: Diethylene glycol ethyl methyl ether = 49.6: 50: 0.4 (weight ratio) and a solid content concentration of 3.5% by weight was obtained. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.
Using this liquid crystal aligning agent, evaluation was performed according to the above method. The evaluation results are shown in Table 1.
Example 2
A solution containing the polymer (1-1) obtained in Synthesis Example 2 and a solution containing the imidized polymer (PI-1) obtained in Synthesis Example 4 were combined with the polymer (1-1 ): The imidized polymer (PI-1) was mixed so that the weight ratio was 5:95, and N, N, N ′, N′-tetraglycidyl-m-xylenediamine as an epoxy compound was added to this. 10 parts by weight was added to 100 parts by weight of the combined coal. NMP and butyl cellosolve were further added thereto to obtain a solution having a solvent composition of NMP: butyl cellosolve: diethylene glycol ethyl methyl ether = 49.6: 50: 0.4 (weight ratio) and a solid content concentration of 3.5% by weight. . After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.
Using this liquid crystal aligning agent, evaluation was performed according to the above method. The evaluation results are shown in Table 1.

Example 3
A solution containing the polymer (1-1) obtained in Synthesis Example 2 and a solution containing the imidized polymer (PI-2) obtained in Synthesis Example 5 were combined with the polymer (1-1 ): The imidized polymer (PI-2) was mixed so that the weight ratio was 5:95, and N, N, N ′, N′-tetraglycidyl-m-xylenediamine as an epoxy compound was added to this. 10 parts by weight was added to 100 parts by weight of the combined coal. Further, γ-butyrolactone, NMP and butyl cellosolve were added, and the solvent composition was γ-butyrolactone: NMP: butyl cellosolve: diethylene glycol ethyl methyl ether = 40: 29.6: 30: 0.4 (weight ratio), and the solid content concentration was A 3.5 wt% solution was obtained. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.
Using this liquid crystal aligning agent, evaluation was performed according to the above method. The evaluation results are shown in Table 1.
Examples 4-7, 9-12 and 14-16 and Comparative Examples 1 and 2
In Example 2 above, a solution containing the polymer described in Table 1 was used as the polymer solution, and the mixing ratio of the polymer and the solvent was changed as described in Table 1, respectively. A liquid crystal aligning agent was prepared and evaluated in the same manner as described above.
The evaluation results are shown in Table 1.

Examples 8 and 13
In Example 3 above, a liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 3 except that the mixing ratio of the polymer and the solvent was changed as shown in Table 1.
The evaluation results are shown in Table 1.
Example 17
In Example 1, the same procedure as in Example 1 was used except that the solution containing the polymer (1-2) obtained in Synthesis Example 3 was used instead of the solution containing the polymer (1-1). A liquid crystal aligning agent was prepared and evaluated.
The evaluation results are shown in Table 1.
Examples 18 and 20-22
In the above Example 2, a liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 2 except that a solution containing the polymer described in Table 1 was used as the polymer solution.
The evaluation results are shown in Table 1.
Example 19
Example 3 was the same as Example 3 except that the solution containing the polymer (1-2) obtained in Synthesis Example 3 was used instead of the solution containing the polymer (1-1). A liquid crystal aligning agent was prepared and evaluated.
The evaluation results are shown in Table 1.

Comparative Example 3
NMP and butyl cellosolve are added to the solution containing the imidized polymer (PI-1) obtained in Synthesis Example 4 to dilute, and the solvent composition is NMP: butyl cellosolve = 50: 50 (weight ratio), solid content concentration 3 A 5 wt% solution. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.
Using this liquid crystal aligning agent, evaluation was performed according to the above method. The evaluation results are shown in Table 1.
Comparative Example 4
N, N, N ′, N′-tetraglycidyl-m-xylenediamine is added as an epoxy compound to the solution containing the imidized polymer (PI-1) obtained in Synthesis Example 4 with respect to 100 parts by weight of the polymer. NMP and butyl cellosolve were added thereto and diluted to obtain a solution having a solvent composition of NMP: butyl cellosolve = 50: 50 (weight ratio) and a solid content concentration of 3.5% by weight. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.
Using this liquid crystal aligning agent, evaluation was performed according to the above method. The evaluation results are shown in Table 1.
Comparative Example 5
N, N, N ′, N′-tetraglycidyl-m-xylenediamine was added as an epoxy compound to the solution containing the imidized polymer (PI-5) obtained in Synthesis Example 8 with respect to 100 parts by weight of the polymer. 10 parts by weight, and γ-butyrolactone, NMP and butyl cellosolve are added thereto for dilution, and the solvent composition is γ-butyrolactone: NMP: butyl cellosolve = 40: 30: 30 (weight ratio), solid content concentration 3.5 weight % Solution. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.
Using this liquid crystal aligning agent, evaluation was performed according to the above method. The evaluation results are shown in Table 1.
Comparative Examples 6-8
In the above Comparative Example 4, a liquid crystal aligning agent was prepared and evaluated in the same manner as in Comparative Example 4 except that the polymer solution was a solution containing the polymer described in Table 1.
The evaluation results are shown in Table 1.

ただし、第１表の溶媒組成の欄における略称は、それぞれ以下の意味である。
ＮＭＰ：Ｎ−メチル−２−ピロリドン
ＢＣ：ブチルセロソルブ（エチレングリコールモノブチルエーテル）
ＥＤＭ：ジエチレングリコールエチルメチルエーテル
γ−ＢＬ：γ−ブチロラクトン
上記第１表において、本発明の液晶配向剤から形成された液晶配向膜は、優れた信頼性、高い電圧保持率および良好な長期の耐焼付き性をすべて同時に実現できることがわかった（実施例１〜実施例１２）。一方、従来知られている液晶配向剤から形成された液晶配向膜は、上記特性のすべてを同時に満足することができなかった（比較例１〜８）。
上記のような液晶配向膜を具備する本発明の液晶表示素子は、優れた信頼性を示し、且つ熱ストレス印加時の残留ＤＣの蓄積が抑制され、液晶表示素子の焼付きが低減される利点を有する。

However, the abbreviations in the column of solvent composition in Table 1 have the following meanings.
NMP: N-methyl-2-pyrrolidone BC: Butyl cellosolve (ethylene glycol monobutyl ether)
EDM: Diethylene glycol ethyl methyl ether γ-BL: γ-butyrolactone In the above Table 1, the liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention has excellent reliability, high voltage holding ratio and good long-term seizure resistance. It was found that all the properties can be realized simultaneously (Examples 1 to 12). On the other hand, the liquid crystal aligning film formed from the conventionally known liquid crystal aligning agent was not able to satisfy all the said characteristics simultaneously (Comparative Examples 1-8).
The liquid crystal display element of the present invention having the liquid crystal alignment film as described above has excellent reliability, and is advantageous in that the accumulation of residual DC during the application of thermal stress is suppressed and the seizure of the liquid crystal display element is reduced. Have

Claims (10)

Following formula (1)

(In the formula (1), R ^I is a hydrogen atom or a methyl group, A ¹ is a single bond, a methylene group, an alkylene group having 2 to 10 carbon atoms, or the following formula (2)

(In Formula (2), n is an integer of 5-150.)
In the case where A ¹ is a single bond, a methylene group or an alkylene group having 2 to 10 carbon atoms, B ¹ is a fluoroalkyl group having 1 to 10 carbon atoms, and A 1 ^{When 1} is a divalent group represented by the above formula (2), B ¹ is an alkyl group having 1 to 10 carbon atoms or a fluoroalkyl group having 1 to 10 carbon atoms. )
A polymer having a repeating unit represented by:
A liquid crystal aligning agent comprising a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, and at least one polymer selected from the group consisting of imidized polymers thereof. A polymer having a repeating unit represented by the above formula (1) is further represented by the following formula (3):

(In Formula (3), R ^II is a hydrogen atom or a methyl group, A ² is a single bond, a methylene group or an alkylene group having 2 to 10 carbon atoms, and B ² is a cyclic ether structure having 2 to 10 carbon atoms. A group having
The liquid crystal aligning agent of Claim 1 which is a polymer which also has a repeating unit represented by these. The liquid crystal aligning agent of Claim ² whose B2 in the said Formula (3) is group which has a 1, 2- epoxy structure or a 1, 3- epoxy structure. An alkylene group of the formula (3) ^{A 2} is a methylene group or a C2-10 in, ^{B 2} is a group having a 1,2-epoxy structure, the liquid crystal aligning agent of claim 3. A polymer having a repeating unit represented by the above formula (1) is further represented by the following formula (4):

(In Formula (4), R ^III is a hydrogen atom or a methyl group, A ³ is a single bond, a phenylene group, or the following formulas (A ³ -1) to (A ³ -6).

_{^{- (CH 2) k -O- *}} (A 3 -5)
_{^{- (CH 2) m -COO- *}} (A 3 -6)
(I in the above formula is 0 or 2, respectively, j is 0 or 1, respectively, k and m are each an integer of 1 to 6, and "*" bond marked with indicates that binds to B ^3.)
B ³ is a monovalent organic group having 17 to 30 carbon atoms having a steroid skeleton, an alkylcyclohexyl group having an alkyl group having 4 to 8 carbon atoms, or 3 carbon atoms. -30 alkyl groups, difluorophenyl groups, trifluoromethylphenyl groups or trifluoromethoxyphenyl groups. )
The liquid crystal aligning agent of Claim 1 or 2 which is a polymer which also has a repeating unit represented by these. In the above formula (4), B ³ is a monovalent organic group of 17 to 30 carbon atoms having a steroid skeleton, a liquid crystal aligning agent of claim 5. At least one polymer selected from the group consisting of polyamic acid and its imidized polymer is 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2) ', 5'- ON), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane- 2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone and pyromellitic dianhydride Tetracarboxylic dianhydride containing at least one selected from the group consisting of p-phenylenediamine, 4,4'-diaminodiphenylmethane, 2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 4,4 ' A diamine containing at least one selected from the group consisting of -diamino-2,2'-dimethylbiphenyl and 1,3-bis (aminomethyl) cyclohexane Is at least one polymer selected from respond to polyamic acid and the group consisting of the imidized polymer obtained liquid crystal alignment agent according to any one of claims 1 to 6. Diamine is represented by the following formula (D-V)

(In the formula (D-V), R ¹⁵ represents an oxygen atom, a sulfur atom, —CO—, —COO—, —OCO—, —NHCO—, —CONH— or a methylene group, and R ¹⁶ represents a cholestanyl skeleton or cholestenyl. A monovalent group having a skeleton, a monovalent group having a trifluoromethylphenyl group or a trifluoromethoxyphenyl group, or an alkyl group having 1 to 22 carbon atoms, and R ¹⁷ is an alkyl group having 1 to 4 carbon atoms. , A3 is an integer of 0-3.)
The liquid crystal aligning agent as described in any one of Claims 1-7 containing the compound represented by these.   The liquid crystal aligning film formed from the liquid crystal aligning agent as described in any one of Claims 1-8.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 9.