CN107250902B

CN107250902B - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element

Info

Publication number: CN107250902B
Application number: CN201680008950.6A
Authority: CN
Inventors: 杉山崇明; 芦泽亮一; 山口智裕; 佐久间大辅
Original assignee: Nissan Chemical Corp
Current assignee: Nissan Chemical Corp
Priority date: 2015-02-06
Filing date: 2016-02-04
Publication date: 2021-01-26
Anticipated expiration: 2036-02-04
Also published as: KR20230011492A; CN107250902A; JP6662307B2; KR102529347B1; TW201700609A; KR20170113594A; WO2016125871A1; JP2020079232A; JP6795074B2; TWI683857B; JPWO2016125871A1; KR102597729B1

Abstract

The invention provides a liquid crystal aligning agent and a liquid crystal display element, wherein the liquid crystal aligning agent can realize a liquid crystal display element with high response speed and excellent afterimage characteristics derived from AC. A liquid crystal display element is formed by adding a liquid crystal aligning agent and/or a liquid crystal layer to a polymerizable compound represented by formula (1). (X)¹、X²Represents a linking group such as an ether bond; s¹、S²Represents a C2-C9 linear alkylene group; s¹、X¹、X²、S²The selection is made in a left-right asymmetric manner of the molecule. )

Description

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

Technical Field

The present invention relates to a liquid crystal aligning agent that can be suitably used for a liquid crystal display element produced by irradiating liquid crystal molecules with ultraviolet rays in a state where a voltage is applied, a liquid crystal alignment film formed from the liquid crystal aligning agent, and a liquid crystal display element having the liquid crystal alignment film.

Background

A liquid crystal display element of a system (also referred to as a Vertical Alignment (VA) system) in which liquid crystal molecules aligned vertically with respect to a substrate are caused to respond to an electric field may include a step of irradiating ultraviolet rays while applying a voltage to the liquid crystal molecules in a manufacturing process thereof.

As such a liquid crystal display element of a vertical alignment method (psa (polymer suspended alignment) type liquid crystal display or the like), the following techniques are known: a photopolymerizable compound is added to a liquid crystal composition in advance and used together with a vertical alignment film of polyimide or the like, and ultraviolet rays are irradiated while applying a voltage to a liquid crystal cell, thereby increasing the response speed of the liquid crystal (see patent document 1 and non-patent document 1).

In general, the tilt direction of liquid crystal molecules responding to an electric field is controlled by projections provided on a substrate, slits provided on a display electrode, and the like, and it is said that: since a polymer structure in which the tilt direction of liquid crystal molecules is memorized is formed on the liquid crystal alignment film by adding a photopolymerizable compound to the liquid crystal composition and irradiating ultraviolet rays while applying a voltage to the liquid crystal cell, the response speed of the liquid crystal display element is faster than that of a method in which the tilt direction of liquid crystal molecules is controlled only by projections and slits.

Further, it is reported that: by adding the photopolymerizable compound to the liquid crystal alignment film without adding it to the liquid crystal composition, the response speed of the liquid crystal display element becomes fast (SC-PVA type liquid crystal display) (see non-patent document 2).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-307720.

Non-patent document

Non-patent document 1: hanaoka, SID 04DIGEST, P.1200-1202.

Non-patent document 2: K.H Y. -J.Lee, SID 09DIGEST, P.666-668.

Disclosure of Invention

Problems to be solved by the invention

In recent years, further increase in response speed of the liquid crystal display element has been desired, and it is considered that: the response speed of the liquid crystal display element is increased by increasing the amount of the photopolymerizable compound to be added, but the conventional photopolymerizable compound has a property of being hardly soluble in a solvent used for a liquid crystal aligning agent. Therefore, there arises a problem of storage stability in that the photopolymerizable compound is precipitated when the liquid crystal aligning agent is stored. When the liquid crystal display element is exposed to a temperature change in the production process thereof, a part of the polymerizable compound may be eluted from the liquid crystal alignment film into the liquid crystal or may be further crystallized in the liquid crystal. In particular, when the solubility of the polymerizable compound in the liquid crystal is low, it is considered that the polymerizable compound is easily crystallized in the liquid crystal. Crystallization of the polymerizable compound in such a liquid crystal becomes a source of a bright point in the display element, and the display quality of the element is degraded.

Further, as another problem of the liquid crystal display element, there is an afterimage (afterimage), and the afterimage (afterimage) may occur when the same pattern is displayed for a long time. One cause of this afterimage is the accumulation of charge. The afterimage caused by the charge accumulation is also referred to as a DC afterimage, but the afterimage (afterimage) can be suppressed to some extent by applying voltage drive of polarity inversion, that is, polarity inversion drive. On the other hand, even a slight change in pretilt angle produces afterimages. Since the change in pretilt angle affects the V-T characteristics, the transmittance changes even when the same voltage is applied. Since the applied voltage when displaying white is different from the applied voltage when displaying black, the amount of change in the tilt angle differs depending on the applied voltage, and when the entire display is switched to the same gradation, the change in the tilt angle may cause an afterimage to be recognized. Such an afterimage cannot be suppressed even when polarity inversion driving is performed, and is also referred to as AC afterimage.

The present invention is directed to solving the problems of the prior art described above.

Means for solving the problems

The present inventors have made extensive studies to achieve the above object, and as a result, have achieved the present invention whose gist is as follows.

1. A liquid crystal aligning agent comprising: a polymerizable compound represented by the following formula (1), and at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide.

(in the formula, X¹And X²Each independently represents a linking group selected from an ether bond and an ester bond; s¹And S²Each independently represents a linear alkylene group having 2 to 9 carbon atoms; and, the S¹、X¹、X²And S²The selection is made in a left-right asymmetric manner of the molecule. )

2. The liquid crystal aligning agent according to 1, wherein S is contained in the polymerizable compound (1)¹And S²Are alkylene groups having different carbon numbers from each other.

3. The liquid crystal aligning agent according to 1 or 2, wherein X in the polymerizable compound (1)¹And X²One of them is an ether bond and the other is an ester bond; or, X¹Is at the carbonyl side with S¹Bonded ester bond, X²Is on the oxygen atom side with S²A bonded ester group.

4. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein at least 1 polymer selected from the group consisting of polyimide precursors and polyimides has a side chain for vertically aligning liquid crystals.

5. The liquid crystal aligning agent according to any one of claims 1 to 4, wherein at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide further has a photoreactive side chain.

6. A liquid crystal alignment film formed by using the liquid crystal aligning agent according to any one of the above 1 to 5.

7. A liquid crystal display element comprising the liquid crystal alignment film according to claim 6.

8. A method for manufacturing a liquid crystal display element of a vertical alignment type, comprising: a liquid crystal alignment agent containing at least 1 polymer selected from the group consisting of polyimide precursor and polyimide is coated on 2 substrates to form a liquid crystal alignment layer, the 2 substrates are arranged in a manner that the liquid crystal alignment layer is opposite to each other, the liquid crystal layer is clamped between the 2 substrates, and ultraviolet rays are irradiated to the liquid crystal layer while an electric field is applied to the liquid crystal layer,

at least one of the liquid crystal aligning agent and the liquid crystal layer contains a polymerizable compound represented by formula (1).

9. The production process according to the above 8, wherein S is contained in the polymerizable compound (1)¹And S²Are alkylene groups having different carbon numbers from each other.

10. The production process according to the above 8 or 9, wherein, in the polymerizable compound (1), X is¹And X²One of them is an ether bond and the other is an ester bond; or, X¹Is at the carbonyl side with S¹Bonded ester bond, X²Is on the oxygen atom side with S²A bonded ester group.

11. The production method according to any one of the above 8 to 10, wherein at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide has a side chain for vertically aligning liquid crystals.

12. The production method according to any one of the above 8 to 11, wherein at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide further has a photoreactive side chain.

13. A polymerizable compound represented by the following formula (1).

(in the formula, X¹And X²Each independently represents a linking group selected from an ether bond and an ester bond; s¹And S²Each independently represents a linear alkylene group having 2 to 9 carbon atoms; and, S¹、X¹、X²And S²The selection is made in a left-right asymmetric manner of the molecule. )

14. The polymerizable compound according to 13, wherein S in the formula (1)¹And S²Are alkylene groups having different carbon numbers from each other.

15. The polymerizable compound according to 13 or 14, wherein X in the formula (1)¹And X²Either of which is an ether bond and the other is an ester bond; or, X¹Is at the carbonyl side with S¹Bonded ester bond, X²Is on the oxygen atom side with S²A bonded ester group.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a liquid crystal aligning agent containing a novel polymerizable compound which is contained in a liquid crystal aligning agent and/or a liquid crystal layer and can provide a liquid crystal display element having a high response speed and excellent afterimage characteristics derived from AC, a liquid crystal alignment film formed using the liquid crystal aligning agent, and an element having a high response speed, particularly a vertical alignment system can be obtained.

Detailed Description

< polymerizable Compound >

The polymerizable compound contained in the liquid crystal aligning agent of the present invention is represented by the following formula (1).

In the formula (1), X¹、X²、S¹And S²The definitions of (a) and (b) are respectively as shown above. Wherein S is¹And S²Each independently preferably is a C2-C6 linear alkylene group.

As a means for selecting S in a left-right asymmetric manner of the molecule¹、X¹、X²And S²The following methods are preferred: s¹And S²A method of selecting alkylene groups having different carbon numbers from each other (method 1); and, X¹And X²A method of forming left-right asymmetric linking groups with each other is selected (method 2). Here, method 1 and method 2 may also be used in combination.

Specific examples of the method 2 include: x¹And X²A method in which one of them is an ether bond and the other is an ester bond (method 2-1); x¹Is at the carbonyl side with S¹Bonded ester bond, X²Is on the oxygen atom side with S²Method of bonding ester groups (method 2-2).

Among such compounds, compounds containing alkylene groups having carbon numbers different from each other can be obtained by the production method described in international patent application publication No. WO 2012/002513. In addition, when one is an ether bond and the other is an ester bond, in the production method described in international patent application publication No. WO2012/002513, 4- (4-hydroxyphenyl) benzoic acid can be used as a raw material instead of bisphenol.

As a method for making the molecules asymmetric to the left and right, in addition to the above methods 1 to 2, there are the following methods: a method in which the left and right polymerizable groups are different (method 3); a method in which a substituent is introduced in such a manner that the benzene ring is asymmetric in the left-right direction (method 4).

Therefore, the following steps are carried out: by selecting at least 1 method selected from the above methods 1 and 2, the solubility of the polymerizable compound is improved, and the sticking characteristics derived from AC are more excellent than those in the selection methods 3 and 4. The reason for this is not clear, and it is considered that this is because: the reason for the ghost characteristic derived from AC is stacking of ring structures of the polymerizable compound, and it is considered that stacking is not hindered when method 1 or method 2 is selected as compared with the cases of method 3 and method 4.

< polymers derived from polyimide precursors and/or polyimides >

In a liquid crystal display element formed by being contained in a liquid crystal aligning agent and/or a liquid crystal layer, as at least 1 polymer (hereinafter, also referred to as a specific polymer) selected from the group consisting of a polyimide precursor and a polyimide, a known polyimide precursor or polyimide used as a liquid crystal aligning agent can be used. The polyimide precursor specifically includes a polyamic acid and a polyamic acid ester.

The polyimide precursor or polyimide as the specific polymer preferably has a side chain (I) for vertically aligning liquid crystal in the application to PSA-type liquid crystal displays, and preferably further has a photoreactive side chain (II) in addition to the side chain (I) for vertically aligning liquid crystal in the application to SC-PVA-type liquid crystal displays.

< side chain (I) for homeotropically orienting liquid Crystal >

The side chain (I) for vertically aligning a liquid crystal (hereinafter also referred to as side chain a) is a side chain having the ability to vertically align liquid crystal molecules with respect to a substrate, and the structure thereof is not particularly limited as long as it has the ability. Examples of the side chain include a long-chain alkyl group, a fluoroalkyl group, a cyclic group having an alkyl group or a fluoroalkyl group at a terminal, and a steroid group, and the side chain can be suitably used in the present invention. These groups may be directly bonded to the main chain of the specific polymer or may be bonded through an appropriate linking group, as long as they have the above-mentioned ability.

Examples of the side chain A include side chains represented by the following formula (a).

In formula (a), l, m and n each independently represent an integer of 0 or 1; r¹An alkylene group having 1 to 6 carbon atoms, -O-, -COO-, -OCO-, -NH-, -NHCO-, -CONH-, -COOCH₂-、-CH₂OCO-、-CH₂COO-、-OCOCH₂Or an alkylene-ether group having 1 to 3 carbon atoms. R²、R³And R⁴Each independently represents phenylene or cycloalkylene; r⁵Represents a hydrogen atom, an alkyl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, a fluoroalkyl group having 1 to 24 carbon atoms, a fluoroalkoxy group having 1 to 24 carbon atoms, a fluoro group, a cyano group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, a hydroxyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, a fluorine-containing heterocyclic,Or macrocyclic substituents containing them.

As R¹From the viewpoint of ease of synthesis, an alkylene-ether group having 1 to 3 carbon atoms is preferably-O-, -COO-, -CONH-, or the like.

R from the viewpoints of ease of synthesis and ability to vertically align liquid crystals²、R³And R⁴Preferably, l, m, n, R are shown in Table 1 below²、R³And R⁴Combinations of (a) and (b).

[ Table 1]

When at least one of l, m and n is 1, as R⁵Preferably a hydrogen atom, an alkyl group having 2 to 14 carbon atoms or a fluoroalkyl group having 2 to 14 carbon atoms, more preferably a hydrogen atom, an alkyl group having 2 to 12 carbon atoms or a fluoroalkyl group having 2 to 12 carbon atoms. When l, m and n are all 0, R is⁵Preferably an alkyl group having 12 to 22 carbon atoms, a fluoroalkyl group having 12 to 22 carbon atoms, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic substituent containing these, and more preferably an alkyl group having 12 to 20 carbon atoms or a fluoroalkyl group having 12 to 20 carbon atoms.

The ability to vertically align liquid crystals varies depending on the structure of the side chain a, and generally, if the amount of the side chain a contained in the polymer is large, the ability to vertically align liquid crystals is improved, and if the amount of the side chain a is small, the ability is lowered. In addition, the side chain a having a cyclic structure tends to align the liquid crystal vertically even in a small amount as compared with the side chain a having a long chain alkyl group.

The amount of the side chain a in the specific polymer is not particularly limited as long as the liquid crystal alignment film can vertically align liquid crystals. In particular, in a case where the response speed of the liquid crystal is to be further increased in a liquid crystal display element provided with a liquid crystal alignment film, the content of the side chain a is preferably as small as possible within a range in which the vertical alignment can be maintained.

< photoreactive side chain (II) >

The photoreactive side chain (II) (hereinafter also referred to as side chain B) is a crosslinkable side chain having a functional group capable of forming a covalent bond by reacting upon irradiation with ultraviolet light (hereinafter also referred to as a photocrosslinkable group) or a photoradical generating side chain having a functional group capable of generating a radical upon irradiation with ultraviolet light, and the structure thereof is not limited as long as it has such ability.

Examples of such a side chain include side chains having a photocrosslinkable group such as a vinyl group, a propionyl group, a methacryloyl group, an anthracenyl group, a cinnamoyl group, a chalcone group, a coumarin group, a maleimide group, and a stilbene group, and the side chains can be suitably used in the present invention. Examples of the structure that generates radicals by ultraviolet irradiation include an acylphosphine oxide structure, an acetophenone structure, an alkylphenone structure, an anthraquinone structure, a carbazole structure, a xanthone structure, a thioxanthone structure, a triphenylamine structure, a fluorenone structure, a benzaldehyde structure, a benzoin structure, a benzophenone structure, and a fluorene structure, and photo-radicals having these structures can be suitably used to generate side chains. Among them, a side chain having an acetophenone structure, a benzophenone structure, or a benzoin structure is preferable.

These groups may be directly bonded to the main chain of the specific polymer or may be bonded through an appropriate linking group, as long as they have the above-mentioned ability.

Examples of the side chain B include the following formulas (B-1) to (B-3). The side chain represented by formula (b-2) includes a structure having a cinnamoyl group and a methacryloyl group, and the side chain represented by formula (b-3) has a structure that generates a radical by ultraviolet irradiation.

-R⁶-R⁷-R⁸-R⁹ (b-1)

In the formula (b-1), R⁶is-CH₂-、-O-、-COO-、-OCO-、-NHCO-、-CONH-、-NH-、-CH₂O-、-N(CH₃)-、-CON(CH₃) -or-N (CH)₃) CO-. From synthesis containerFrom the viewpoint of easiness, R is⁶Is preferably-CH₂-, -O-, -COO-, -NHCO-, -NH-or-CH₂O-。

R⁷Represents a cyclic, unsubstituted or fluorine atom-substituted alkylene group having 1 to 20 carbon atoms, any-CH of the alkylene groups₂Optionally substituted by-CF₂-or-CH ═ CH-substitution, optionally substituted with any of the groups listed below, where these groups are not adjacent to each other; any of the groups is: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, a carbocyclic ring or a heterocyclic ring.

Specific examples of the carbocyclic ring and the heterocyclic ring include, but are not limited to, the following structures.

R⁸represents-CH₂-、-O-、-CH₂O-、-COO-、-OCO-、-NH-、-CONH-、-NHCO-、-N(CH₃)-、-CON(CH₃)-、-N(CH₃) Any of CO-, carbocyclic or heterocyclic. From the viewpoint of ease of synthesis, -CH is preferred₂-, -O-, -COO-, -OCO-, NHCO-, -NH-, carbocyclic or heterocyclic. Specific examples of the carbocyclic ring and the heterocyclic ring are as described above.

R⁹Is styryl, -CR¹⁸＝CH₂A group, a carbocyclic ring, a heterocyclic ring, or the following formulae (R9-1) to (R9-34), R¹⁸Represents a hydrogen atom or a methyl group optionally substituted by a fluorine atom.

Wherein R is a group represented by⁹More preferably, styryl, -CH ═ CH₂、-C(CH₃)＝CH₂Or (R9-2) above,(R9-12) or (R9-15).

-R¹⁰-R¹¹-R¹²-R¹³-R¹⁴-R¹⁵ (b-2)

In the above formula (b-2), R¹⁰is-CH₂-, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-or-CO-.

R¹¹Is alkylene with 1 to 30 carbon atoms, divalent carbocycle or divalent heterocycle, and more than 1 hydrogen atom in the alkylene, the divalent carbocycle and the divalent heterocycle is optionally replaced by fluorine atom or organic group. Furthermore, R¹¹Any of-CH₂-optionally substituted by any of the groups listed below, if these groups are not adjacent to each other; any of the groups is: -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-, -NHCONH-or-CO-.

R¹²is-CH₂-, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, -CO-or a single bond.

R¹³Is a cinnamoyl group, a chalcone group or a coumarin group, and represents a photo-crosslinking group.

R¹⁴Is a single bond, alkylene with 1 to 30 carbon atoms, a divalent carbocycle or a divalent heterocycle, and more than 1 hydrogen atom in the alkylene, the divalent carbocycle or the divalent heterocycle is optionally substituted by fluorine atom or organic group. Furthermore, R¹⁴Any of-CH₂-optionally substituted by any of the groups listed below, in case these groups are not adjacent to each other; any of the groups is: -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-, -NHCONH-or-CO-.

R¹⁵Is an acryloyl group or a methacryloyl group and represents a photopolymerizable group.

Among the side chains represented by the formula (b-2), as-R¹³-R¹⁴-R¹⁵Specific examples of the group include, but are not limited to, the following structures. In the following structures, R represents a hydrogen atom or a methyl group.

In the formula (b-3), Ar₄Represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene and biphenylene, which are optionally substituted with an organic group, and hydrogen atoms on these groups are optionally substituted with halogen atoms.

R₁₆And R₁₇Each independently an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a benzyl group or a phenethyl group, and when R is an alkyl group or an alkoxy group₁₆And R₁₇Optionally forming a ring.

T₁And T₂Each independently represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH₂O-、-N(CH₃)-、-CON(CH₃) -or-N (CH)₃) A CO-linking group.

S⁴Represents a single bond, or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom (wherein-CH in the alkylene group₂-or-CF₂-optionally substituted by-CH ═ CH-optionally substituted by any of the groups listed below, where these groups are not adjacent to each other; any of the groups is: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, a divalent carbocyclic ring or a divalent heterocyclic ring).

n2 represents 0 or 1. Q represents a structure represented by the following formula.

(wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R₃represents-CH₂-, -NR-, -O-or-S-)

Among the side chains represented by the formula (b-3), as-Ar₄-CO-CQR¹⁶R¹⁷Specific examples of the group include, but are not limited to, the following structures of formulae (b-3-1) to (b-3-6).

The amount of the side chain B in the specific polymer is not particularly limited as long as it is within a range that can increase the response speed of the liquid crystal in the liquid crystal display element. When the response speed of the liquid crystal in the liquid crystal display element is to be further increased, it is preferable to increase the response speed as much as possible within a range not affecting other characteristics.

< polyimide precursor >

The polyimide precursor refers to polyamic acid and polyamic acid ester. The following description will be made of a method for producing a polyamic acid, but a polyamic acid ester can be produced by a conventionally known method, the same method as or similar to the polyamic acid described below.

< Polyamic acid >

The polyamic acid having a side chain a can be obtained by reacting a raw material diamine or tetracarboxylic acid anhydride, either or both of which have a side chain a. Among them, a method using a diamine having a side chain a is preferable in terms of ease of raw material synthesis and the like.

The polyamic acid having a side chain a and a side chain B is obtained by reacting raw materials of a diamine and a tetracarboxylic anhydride, the raw materials including a diamine and a tetracarboxylic anhydride, the diamine including a side chain a and a side chain B, the diamine including a side chain B. Among them, from the viewpoint of ease of synthesis of raw materials and the like, it is preferable that only the diamine contains the side chain a and the side chain B.

< diamine having side chain A >

Examples of the diamine having a side chain a (hereinafter referred to as diamine a) include diamines having an alkyl group, a fluoroalkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic substituent containing these groups in the side chain of the diamine. Specifically, diamines having a side chain represented by the above formula (a) are exemplified. More specifically, the diamines represented by the following formulae (1), (3), (4) and (5) are exemplified, but not limited thereto. In the formula (1), l, m, n and R¹～R⁵The definition of (a) is the same as that of the formula (a).

In the formulae (3) and (4), A₁₀Each independently represents-COO-, -OCO-, -CONH-, -NHCO-, -CH₂-, -O-, -CO-or-NH-; a. the₁₁Represents a single bond or phenylene; a represents a side chain A; a' represents an alkyl group, a fluoroalkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic substituent formed by a combination of any of these structures.

In the formula (5), A₁₄Is C3-20 alkyl optionally substituted by fluorine atom; a. the₁₅Is 1, 4-cyclohexylene or 1, 4-phenylene; a. the₁₆Is oxygen atom or-COO- (-wherein the bond with "+" is bonded to A)₃Bonding is performed); a. the₁₇Is oxygen atom or-COO-bonded bond with (CH)₂)a₂Bonding is performed). In addition, a₁Is an integer of 0 or 1; a is₂Is an integer of 2 to 10; a is₃Is an integer of 0 or 1. )

Two amino groups (-NH) in the formula (1)₂) The bonding position of (2) is not limited. Specifically, there may be mentioned: the linking group with respect to the side chain is a position of 2,3, a position of 2,4, a position of 2,5, a position of 2,6, a position of 3,4, a position of 3,5 on the benzene ring. Among them, from the viewpoint of reactivity in synthesizing a polyamic acid, a position of 2,4, a position of 2,5, or a position of 3,5 is preferable. In view of the easiness of synthesizing the diamine, the 2,4 position or the 3,5 position is more preferable.

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

Formula [ A-1]-formula [ A-5]In (A)₁Is an alkyl group having 2 to 24 carbon atoms or a fluoroalkyl group having 2 to 24 carbon atoms.

Formula [ A-6]And formula [ A-7]In (A)₂represents-O-, -OCH₂-、-CH₂O-、-COOCH₂-or-CH₂OCO-；A₃Is an alkyl group having 1 to 22 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, a fluoroalkyl group having 1 to 22 carbon atoms or a fluoroalkoxy group having 1 to 22 carbon atoms.

Formula [ A-8]-formula [ A-10]In (A)₄represents-COO-, -OCO-, -CONH-, -NHCO-, -COOCH₂-、-CH₂OCO-、-CH₂O-、-OCH₂-or-CH₂-；A₅Is an alkyl group having 1 to 22 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, a fluoroalkyl group having 1 to 22 carbon atoms or a fluoroalkoxy group having 1 to 22 carbon atoms.

Formula [ A-11]And formula [ A-12]In (A)₆represents-COO-, -OCO-, -CONH-, -NHCO-, -COOCH₂-、-CH₂OCO-、-CH₂O-、-OCH₂-、-CH₂-, -O-or-NH-; a. the₇Is fluoro, cyano, trifluoromethyl, nitro, azo, formyl, acetyl, acetoxy or hydroxy.

Formula [ A-13]And formula [ A-14]In (A)₈The carbon number of the alkyl is 3-12, and cis-trans isomers of 1, 4-cyclohexylene are trans isomers respectively.

Formula [ A-15]And formula [ A-16]In (A)₉The carbon number of the alkyl is 3-12, and cis-trans isomers of 1, 4-cyclohexylene are trans isomers respectively.

Specific examples of the diamine represented by the formula (3) include diamines represented by the following formulae [ A-25] to [ A-30], but are not limited thereto.

(A₁₂represents-COO-, -OCO-, -CONH-, -NHCO-, -CH₂-, -O-, -CO-or-NH-; a. the₁₃Represents an alkyl group having 1 to 22 carbon atoms or a fluoroalkyl group having 1 to 22 carbon atoms. )

Specific examples of the diamine represented by the formula (4) include diamines represented by the following formulae [ A-31] to [ A-32], but are not limited thereto.

Among these, diamines of [ A-1], [ A-2], [ A-3], [ A-7], [ A-14], [ A-16], [ A-21] or [ A-22] are preferable from the viewpoint of the ability to vertically align liquid crystals and the response speed of liquid crystals.

The diamine may be used in 1 kind or 2 or more kinds in combination depending on the characteristics such as liquid crystal alignment property, pretilt angle, voltage holding property, and accumulated charge when a liquid crystal alignment film is formed.

The diamine component for the synthesis of the polyamic acid having the side chain a may be 5 to 70 mol%, preferably 10 to 50 mol%, and more preferably 20 to 50 mol% based on 100 mol% of the diamine component.

< diamine having side chain B >

Examples of the diamine having a side chain B (hereinafter also referred to as "diamine B") include diamines having a photo-crosslinking group such as a vinyl group, an acryloyl group, a methacryloyl group, an anthracenyl group, a cinnamoyl group, a chalcone group, a coumarin group, a maleimide group, or a stilbene group in a side chain of the diamine; having a functional group which generates a radical upon irradiation with ultraviolet raysThe diamine of (1). Specifically, diamines having side chains represented by the above-mentioned formulas (b-1) to (b-3) are exemplified. Specific examples thereof include the following general formula (2) (R in formula (2))⁶、R⁷、R⁸And R⁹The definition of (b) is the same as that of the diamine represented by the formula (b-1), but the diamine is not limited thereto.

Two amino groups (-NH) in the formula (2)₂) The bonding position (2) is not particularly limited. Specifically, the linking group to the side chain includes a position of 2,3, a position of 2,4, a position of 2,5, a position of 2,6, a position of 3,4, and a position of 3,5 on the benzene ring. Among them, from the viewpoint of reactivity in synthesizing a polyamic acid, a position of 2,4, a position of 2,5, or a position of 3,5 is preferable. In view of the easiness of synthesizing the diamine, the 2,4 position or the 3,5 position is more preferable.

Specific examples thereof include, but are not limited to, the following compounds. In the following compounds, X represents a linking group selected from the group consisting of an ether, an ester, an amide and an amino group; r represents a hydrogen atom or a methyl group; s³Represents a single bond or an alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom. In addition, l, m and n each independently represent an integer of 0 to 20.

The diamine may be used in 1 kind or 2 or more kinds in combination depending on the characteristics such as liquid crystal alignment property, pretilt angle, voltage holding property, and accumulated charge when a liquid crystal alignment film is formed, and the response speed of liquid crystal when a liquid crystal display element is formed.

The diamine B is 0 to 95 mol%, preferably 20 to 80 mol%, and more preferably 40 to 70 mol% based on 100 mol% of the diamine component used for the synthesis of the polyamic acid.

< other diamines >

The polyamic acid used in the present invention may be used as a diamine component in combination with other diamines other than the above-described diamine having a side chain for vertically aligning liquid crystal and the diamine having a photoreactive group, within a range not impairing the effect of the present invention. Specific examples thereof include p-phenylenediamine, 2,3,5, 6-tetramethylp-phenylenediamine, 2, 5-dimethylphenylenediamine, m-phenylenediamine, 2, 4-dimethylm-phenylenediamine, 2, 5-diaminotoluene, 2, 6-diaminotoluene, 2, 5-diaminophenol, 2, 4-diaminophenol, 3, 5-diaminobenzyl alcohol, 2, 4-diaminobenzyl alcohol, 4, 6-diaminoresorcinol, 4 ' -diaminobiphenyl, 3 ' -dimethyl-4, 4 ' -diaminobiphenyl, 3 ' -dimethoxy-4, 4 ' -diaminobiphenyl, 3 ' -dihydroxy-4, 4 ' -diaminobiphenyl, 3,3 '-dicarboxy-4, 4' -diaminobiphenyl, 3 '-difluoro-4, 4' -biphenyl, 3 '-trifluoromethyl-4, 4' -diaminobiphenyl, 3 '-diaminobiphenyl, 2' -diaminobiphenyl, 2,3 '-diaminobiphenyl, 4' -diaminodiphenylmethane, 3 '-diaminodiphenylmethane, 3, 4' -diaminodiphenylmethane, 2 '-diaminodiphenylmethane, 2, 3' -diaminodiphenylmethane, 4 '-diaminodiphenyl ether, 3' -diaminodiphenyl ether, 3,4 '-diaminodiphenyl ether, 2' -diaminodiphenyl ether, 2,3 '-diaminodiphenyl ether, 2, 4' -diaminodiphenyl ether, and mixtures thereof, 2,3 '-diaminodiphenyl ether, 4' -sulfonyldiphenylamine, 3 '-sulfonyldiphenylamine, bis (4-aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4' -thiodiphenylamine, 3 '-thiodiphenylamine, 4' -diaminodiphenylamine, 3 '-diaminodiphenylamine, 3, 4' -diaminodiphenylamine, 2 '-diaminodiphenylamine, 2, 3' -diaminodiphenylamine, N-methyl (4,4 '-diaminodiphenyl) amine, N-methyl (3, 3' -diaminodiphenyl) amine, N-methyl-substituted diphenylamines, N-substituted diphenylamines, n-methyl (3,4 '-diaminodiphenyl) amine, N-methyl (2, 2' -diaminodiphenyl) amine, N-methyl (2,3 '-diaminodiphenyl) amine, 4' -diaminobenzophenone, 3 '-diaminobenzophenone, 3, 4' -diaminobenzophenone, 1, 4-diaminonaphthalene, 2 '-diaminobenzophenone, 2, 3' -diaminobenzophenone, 1, 5-diaminonaphthalene, 1, 6-diaminonaphthalene, 1, 7-diaminonaphthalene, 1, 8-diaminonaphthalene, 2, 5-diaminonaphthalene, 2, 6-diaminonaphthalene, 2, 7-diaminonaphthalene, 2, 8-diaminonaphthalene, 1, 2-bis (4-aminophenyl) ethane, 1, 2-bis (3-aminophenyl) ethane, 1, 3-bis (4-aminophenyl) propane, 1, 3-bis (3-aminophenyl) propane, 1, 4-bis (4-aminophenyl) butane, 1, 4-bis (3-aminophenyl) butane, bis (3, 5-diethyl-4-aminophenyl) methane, 1, 4-bis (4-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 1, 4-bis (4-aminophenyl) benzene, 1, 3-bis (4-aminophenyl) benzene, 1, 4-bis (4-aminobenzyl) benzene, 1, 3-bis (4-aminophenoxy) benzene, 4 '- [1, 4-phenylenebismethylene ] diphenylamine, 1, 3-bis (4-aminophenoxy) benzene, 4' -phenylenebismethylene ] diphenylamine, and mixtures thereof, 4,4 ' - [1, 3-phenylenebismethylene ] diphenylamine, 3,4 ' - [1, 4-phenylenebismethylene ] diphenylamine, 3,4 ' - [1, 3-phenylenebismethylene ] diphenylamine, 3 ' - [1, 4-phenylenebismethylene ] diphenylamine, 3 ' - [1, 3-phenylenebismethylene ] diphenylamine, 1, 4-phenylenebis [ (4-aminophenyl) methanone ], 1, 4-phenylenebis [ (3-aminophenyl) methanone ], 1, 3-phenylenebis [ (4-aminophenyl) methanone ], 1, 3-phenylenebis [ (3-aminophenyl) methanone ], 1, 4-phenylenebis (4-aminobenzoate), 1, 4-phenylenebis (3-aminobenzoate), 1, 3-phenylenebis (4-aminobenzoate), 1, 3-phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) isophthalate, N '- (1, 4-phenylene) bis (4-aminobenzamide), N' - (1, 3-phenylene) bis (4-aminobenzamide), N '- (1, 4-phenylene) bis (3-aminobenzamide), N' - (1, 4-aminobenzamide), N '- (1, 3-phenylene) bis (3-aminobenzamide), N' -bis (4-aminophenyl) terephthalamide, N, N '-bis (3-aminophenyl) terephthalamide, N' -bis (4-aminophenyl) isophthalamide, N '-bis (3-aminophenyl) isophthalamide, 9, 10-bis (4-aminophenyl) anthracene, 4' -bis (4-aminophenoxy) diphenylsulfone, 2 '-bis [4- (4-aminophenoxy) phenyl ] propane, 2' -bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane, 2 '-bis (4-aminophenyl) hexafluoropropane, 2' -bis (3-amino-4-methylphenyl) hexafluoropropane, N '-bis (4-aminophenyl) isophthalamide, N' -bis (3-aminophenyl) isophthalamide, 9, 10-bis (4-aminophenyl) anthracene, 2,2 '-bis (4-aminophenyl) propane, 2' -bis (3-amino-4-methylphenyl) propane, 3, 5-diaminobenzoic acid, 2, 5-diaminobenzoic acid, bis (4-aminophenoxy) methane, 1, 2-bis (4-aminophenoxy) ethane, 1, 3-bis (4-aminophenoxy) propane, 1, 3-bis (3-aminophenoxy) propane, 1, 4-bis (4-aminophenoxy) butane, 1, 4-bis (3-aminophenoxy) butane, 1, 5-bis (4-aminophenoxy) pentane, 1, 5-bis (3-aminophenoxy) pentane, 2 '-bis (3-aminophenyl) propane, 2' -bis (3-aminophenyl) propane, 3, 5-diaminobenzoic acid, 2,5, 1, 6-bis (4-aminophenoxy) hexane, 1, 6-bis (3-aminophenoxy) hexane, 1, 7-bis (4-aminophenoxy) heptane, 1, 7-bis (3-aminophenoxy) heptane, 1, 8-bis (4-aminophenoxy) octane, 1, 8-bis (3-aminophenoxy) octane, 1, 9-bis (4-aminophenoxy) nonane, 1, 9-bis (3-aminophenoxy) nonane, 1, 10-bis (4-aminophenoxy) decane, 1, 10-bis (3-aminophenoxy) decane, 1, 11-bis (4-aminophenoxy) undecane, 1, 11-bis (3-aminophenoxy) undecane, 1, 12-bis (4-aminophenoxy) dodecane, 1, 10-bis (3-aminophenoxy) decane, 1, 11-bis (4-aminophenoxy) undecane, 1, 11-bis (3-aminophenoxy) undecane, 1, 12-bis (4-aminopheno, Aromatic diamines such as 1, 12-bis (3-aminophenoxy) dodecane, alicyclic diamines such as bis (4-aminocyclohexyl) methane and bis (4-amino-3-methylcyclohexyl) methane, aliphatic diamines such as 1, 3-diaminopropane, 1, 4-diaminobutane, 1, 5-diaminopentane, 1, 6-diaminohexane, 1, 7-diaminoheptane, 1, 8-diaminooctane, 1, 9-diaminononane, 1, 10-diaminodecane, 1, 11-diaminoundecane and 1, 12-diaminododecane.

The other diamines may be used in 1 kind or in combination of 2 or more kinds depending on the properties such as liquid crystal alignment properties, pretilt angle, voltage holding properties, and accumulated charge when a liquid crystal alignment film is formed.

< tetracarboxylic dianhydride >

In the synthesis of the polyamic acid used in the present invention, the tetracarboxylic dianhydride to be reacted with the diamine component is not particularly limited. Specific examples thereof are listed below.

Examples thereof include pyromellitic acid, 2,3,6, 7-naphthalenetetracarboxylic acid, 1,2,5, 6-naphthalenetetracarboxylic acid, 1,4,5, 8-naphthalenetetracarboxylic acid, 2,3,6, 7-anthracenetetracarboxylic acid, 1,2,5, 6-anthracenetetracarboxylic acid, 3,3 ', 4, 4' -biphenyltetracarboxylic acid, 2,3,3 ', 4' -biphenyltetracarboxylic acid, bis (3, 4-dicarboxyphenyl) ether, 3,3 ', 4, 4' -benzophenonetetracarboxylic acid, bis (3, 4-dicarboxyphenyl) sulfone, bis (3, 4-dicarboxyphenyl) methane, 2-bis (3, 4-dicarboxyphenyl) propane, 1,1,1,3,3, 3-hexafluoro-2, 2-bis (3, 4-dicarboxyphenyl) propane, bis (3, 4-dicarboxyphenyl) dimethylsilane, bis (3, 4-dicarboxyphenyl) diphenylsilane, 2,3,4, 5-pyridinetetracarboxylic acid, 2, 6-bis (3, 4-dicarboxyphenyl) pyridine, 3 ', 4, 4' -diphenylsulfonetetracarboxylic acid, 3,4,9, 10-perylenetetracarboxylic acid, 1, 3-diphenyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, oxydiphthalic tetracarboxylic acid, 1,2,3, 4-cyclobutanetetracarboxylic acid, 1,2,3, 4-cyclopentanetetracarboxylic acid, 1,2,4, 5-cyclohexanetetracarboxylic acid, 1,2,3, 4-tetramethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, 1, 2-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, 1,2,3, 4-cycloheptanetetracarboxylic acid, 2,3,4, 5-tetrahydrofurantetracarboxylic acid, 3, 4-dicarboxy-1-cyclohexylsuccinic acid, 2,3, 5-tricarboxycyclopentylacetic acid, 3, 4-dicarboxy-1, 2,3, 4-tetrahydro-1-naphthalenecarboxylic acid, bicyclo [3,3,0] octane-2, 4,6, 8-tetracarboxylic acid, bicyclo [4,3,0] nonane-2, 4,7, 9-tetracarboxylic acid, bicyclo [4,4,0] decane-2, 4,8, 10-tetracarboxylic acid, tricyclo [6.3.0.0<2,6> ] undecane-3, 5,9, 11-tetracarboxylic acid, 1,2,3, 4-butanetetracarboxylic acid, 4- (2, 5-dioxatetrahydrofuran-3-yl) -1,2,3, 4-tetrahydronaphthalene-1, 2-dicarboxylic acid, bicyclo [2,2,2] oct-7-ene-2, 3,5, 6-tetracarboxylic acid, 5- (2, 5-dioxatetrahydrofuryl) -3-methyl-3-cyclohexane-1, 2-dicarboxylic acid, tetracyclo [6,2,1,1,0,2,7] dodecane-4, 5,9, 10-tetracarboxylic acid, 3,5, 6-tricarboxynorbornane-2: 3,5: 6-dicarboxylic acid, 1,2,4, 5-cyclohexanetetracarboxylic acid, and the like.

The tetracarboxylic dianhydride can be used in 1 kind or in combination of 2 or more kinds depending on the properties such as liquid crystal alignment properties, voltage holding properties, and accumulated charges when a liquid crystal alignment film is formed.

< Synthesis of Polyamic acid >

When the diamine component is reacted with the tetracarboxylic dianhydride to obtain the polyamic acid, a known synthesis method can be used. Generally, the method is a method of reacting a diamine component with a tetracarboxylic dianhydride in an organic solvent. The reaction of the diamine component with the tetracarboxylic dianhydride is advantageous in that it is relatively easy to proceed in an organic solvent and no by-product is produced.

The organic solvent used in the above reaction is not particularly limited as long as it dissolves the produced polyamic acid. Further, the organic solvent which does not dissolve the polyamic acid may be used by mixing the polyamic acid with the solvent in a range where the produced polyamic acid does not precipitate. The organic solvent is preferably used after dehydration and drying because the water content in the organic solvent suppresses the polymerization reaction and causes hydrolysis of the polyamic acid to be produced.

Examples of the organic solvent include N, N-dimethylformamide, N-dimethylacetamide, N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylsulfoxide, gamma-butyrolactone, isopropanol, methoxymethylpentanol, dipentene, ethylpentyl ketone, methylnonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, and the like, Butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol tertiary-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, methyl carbitol, ethylene glycol monoacetate, propylene glycol monobutyl ether, propylene glycol monoacetate, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl glutarate, ethyl glutarate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 2-ethyl-1-hexanol, and the like. These organic solvents may be used alone or in combination.

When the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, the following method can be mentioned: a method in which a solution obtained by dispersing or dissolving a diamine component in an organic solvent is stirred, and a tetracarboxylic dianhydride component is directly added or the tetracarboxylic dianhydride component is dispersed or dissolved in the organic solvent and then added; conversely, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent; a method of alternately adding a tetracarboxylic dianhydride component and a diamine component, and any of these methods can be used. When the diamine component or the tetracarboxylic dianhydride component is formed of a plurality of compounds, the diamine component or the tetracarboxylic dianhydride component may be reacted in a mixed state in advance, or may be reacted in sequence, or low-molecular-weight materials obtained by the respective reactions may be mixed to produce a high-molecular-weight material.

The temperature at which the diamine component and the tetracarboxylic dianhydride component are reacted may be selected from any temperature, and is, for example, in the range of-20 to 150 ℃, preferably-5 to 100 ℃. The reaction may be carried out at any concentration, for example, 1 to 50% by mass, preferably 5 to 30% by mass.

The ratio of the total number of moles of the tetracarboxylic dianhydride component to the total number of moles of the diamine component in the polymerization reaction can be arbitrarily selected depending on the molecular weight of the polyamic acid to be obtained. Similarly to the ordinary polycondensation reaction, the molecular weight of the polyamic acid to be produced increases as the molar ratio approaches 1.0. The preferable range is 0.8 to 1.2.

The method for synthesizing polyamic acid used in the present invention is not limited to the above method, and as in the case of the general method for synthesizing polyamic acid, a corresponding polyamic acid can be obtained by using a tetracarboxylic acid derivative such as a tetracarboxylic acid or a tetracarboxylic acid dihalide having a corresponding structure in place of the tetracarboxylic acid dianhydride and reacting the tetracarboxylic acid derivative by a known method.

Examples of the method for imidizing the polyamic acid to obtain a polyimide include: thermal imidization by directly heating a solution of polyamic acid; catalytic imidization by adding a catalyst to a solution of polyamic acid.

In the polyimide used in the present invention, the imidization ratio of the polyamic acid to the polyimide is not necessarily 100%.

The polyamic acid is thermally imidized in a solution at a temperature of 100 to 400 ℃, preferably 120 to 250 ℃, preferably while discharging water generated by the imidization reaction to the outside of the system.

The catalytic imidization of the polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring at-20 to 250 ℃, preferably 0 to 180 ℃. The amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times, the amount of the acid anhydride is 1 to 50 times, preferably 3 to 30 times, the amount of the acid amide group. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine, and among these, pyridine is preferable because it has a basic property suitable for promoting the reaction. The acid anhydride includes acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like, and among these, acetic anhydride is preferable because purification after completion of the reaction is easy if it is used. The imidization rate based on the catalytic imidization can be controlled by adjusting the amount of the catalyst and the reaction temperature, the reaction time, and the like.

When the polyimide precursor or polyimide to be produced is recovered from the reaction solution of the polyimide precursor or polyimide, the reaction solution may be precipitated by adding the reaction solution to a poor solvent. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer precipitated by charging the poor solvent may be recovered by filtration, and then dried at normal temperature or under reduced pressure or dried by heating. Further, if the operation of re-dissolving the precipitated and recovered polymer in the organic solvent and re-recovering the precipitate is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent in this case include alcohols, ketones, hydrocarbons, and the like, and if 3 or more kinds of poor solvents selected from these are used, the purification efficiency is further improved, which is preferable.

< liquid Crystal alignment agent >

The liquid crystal aligning agent of the present invention contains the polymerizable compound represented by the formula (1) and at least 1 polymer selected from the group consisting of polyimide precursors and polyimides. In addition to these components, other polymer components for forming a resin coating film may be contained. The content of the total resin component is 1 to 20 mass%, preferably 3 to 15 mass%, more preferably 3 to 10 mass% in 100 mass% of the liquid crystal aligning agent.

The resin component in the liquid crystal aligning agent of the present invention may be all at least 1 polymer selected from the group consisting of polyimide precursors having a side chain a and/or a side chain B and polyimides, or a mixture thereof, and further, other polymers may be mixed. In this case, the content of the other polymer in the resin component is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass.

Examples of the other polymer include, but are not limited to, polyimide precursors or polyimides having no side chain B, and polyimide precursors or polyimides having neither side chain a nor side chain B.

The polymer molecular weight of the resin component is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000 in terms of the strength of the obtained coating film, workability in forming the coating film, coating film uniformity, and the like, and the weight average molecular weight (Mw) measured by GPC (Gel Permeation Chromatography) method.

The content of the polymerizable compound represented by formula (1) in the liquid crystal aligning agent of the present invention is 3 to 30 parts by mass, preferably 5 to 20 parts by mass, and more preferably 5 to 15 parts by mass, based on 100 parts by mass of the resin component. At the content, the effects of the present invention can be obtained.

< solvent >

The organic solvent used in the liquid crystal aligning agent of the present invention is not particularly limited as long as it is an organic solvent capable of dissolving the resin component. The organic solvent may be 1 kind of solvent, or a mixed solvent of 2 or more kinds. Specific examples of the organic solvent include those exemplified in the synthesis of the polyamic acid. Among them, from the viewpoint of the solubility of the resin component, N-methyl-2-pyrrolidone, γ -butyrolactone, N-ethyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, or 3-methoxy-N, N-dimethylpropane amide is preferable.

The solvent as described below is preferably used by being mixed with a solvent having an effect of improving the uniformity and smoothness of the coating film and having high solubility of the resin component.

Examples thereof include isopropyl alcohol, methoxymethyl amyl alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol acetate, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, dipropylene glycol monoacetate, and the like, Tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl glutarate, ethyl glutarate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, ethyl isobutyl acetate, butyl acetate, ethyl propionate, butyl acetate, ethyl glutarate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropion, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, 2-ethyl-1-hexanol, and the like. These solvents may be used in combination. When these solvents are used, the amount of the solvent is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, based on the total amount of the solvent contained in the liquid crystal aligning agent.

The liquid crystal aligning agent may contain components other than those described above. Examples of the compound include compounds for improving the film thickness uniformity and surface smoothness when the liquid crystal aligning agent is applied; and compounds for improving the adhesion between the liquid crystal alignment film and the substrate.

Examples of the compound for improving the film thickness uniformity and surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant. More specifically, examples thereof include Eftop EF301, EF303, EF352 (manufactured by Tohkem products Corporation)), Megafac F171, F173, R-30 (manufactured by Dainippon ink Co., Ltd.), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by Asahi Nitroson Co., Ltd.). When these surfactants are used, the use ratio thereof is preferably 0.01 to 2 parts by mass, and more preferably 0.01 to 1 part by mass, per 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

Specific examples of the compound for improving the adhesion between the liquid crystal alignment film and the substrate include a functional silane-containing compound, an epoxy-containing compound, and the like. Examples thereof 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-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1, 4, 7-triazacyclodecane, 10-triethoxysilyl-1, 4, 7-triazacyclodecane, 9-trimethoxysilyl-3, 6-diaza-nonyl acetate, 9-triethoxysilyl-3, 6-diaza-nonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, N-methyl-3-aminopropyltrimethoxysilane, N-methyl-3-aminopropyltriethoxysilane, N-methyl-3-aminopropyltrimethoxysilane, ethylene glycol diglycidyl ether, N-methyl-ethyl-3-hydroxyethylene, N-methyl-ethyl-3-, Polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2-dibromoneopentyl glycol diglycidyl ether, 1,3,5, 6-tetraglycidyl-2, 4-hexanediol, N, N, N ', N ', -tetraglycidyl-m-xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N ', -tetraglycidyl-4, 4 ' -diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, n-diglycidyl) aminopropyltrimethoxysilane, and the like.

In addition, in order to further improve the abrasion resistance of the coating film obtained from the liquid crystal aligning agent, a phenol compound such as 2,2' -bis (4-hydroxy-3, 5-dihydroxymethylphenyl) propane or tetrakis (methoxymethyl) bisphenol may be added. When these compounds are used, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

In addition to the above, a dielectric or conductive material for changing electrical characteristics such as dielectric constant and conductivity of the liquid crystal alignment film may be added to the liquid crystal alignment agent of the present invention within a range not to impair the effects of the present invention.

< liquid Crystal alignment film >

The cured film obtained by applying the liquid crystal aligning agent of the present invention to a substrate, drying and baking the applied liquid crystal aligning agent as needed may be used as a liquid crystal alignment film. The cured film may be subjected to brushing, irradiation with polarized light, light of a specific wavelength, or the like, or treatment with an ion beam or the like to form an alignment film for SC-PVA, and the liquid crystal display element filled with the liquid crystal may be irradiated with UV while a voltage is applied thereto.

The substrate is not particularly limited as long as it is a highly transparent substrate, and a glass plate, polycarbonate, poly (meth) acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether ketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth) acrylonitrile, triacetyl cellulose, diacetyl cellulose, acetate butyrate cellulose, or the like can be used. In addition, from the viewpoint of simplifying the process, a substrate on which an ITO (Indium Tin Oxide) electrode or the like for driving a liquid crystal is formed is preferably used. In the reflective liquid crystal display element, an opaque material such as a silicon wafer may be used as long as it is a single-sided substrate, and a material that reflects light such as aluminum may be used as an electrode in this case.

The method for applying the liquid crystal aligning agent is not particularly limited, and examples thereof include: printing methods such as screen printing, gravure printing, and flexographic printing; ink-jet methods, spray methods, roll coating methods, dipping, roll coaters, slit coaters, spin coaters, and the like. In terms of productivity, the transfer printing method is widely used industrially, and can be suitably used in the present invention.

The coating film formed by applying the liquid crystal aligning agent by the above-mentioned method can be fired to form a cured film. The drying step after the liquid crystal alignment agent is applied is not essential, and when the time from the application to the firing of each substrate is not uniform or the firing is not performed immediately after the application, the drying step is preferably performed. The drying is not particularly limited as long as the solvent is removed to such an extent that the shape of the coating film is not deformed by conveyance of the substrate or the like. For example, the drying may be performed for 0.5 to 30 minutes, preferably 1 to 5 minutes, on a hot plate at a temperature of 40 to 150 ℃, preferably 60 to 100 ℃.

The firing temperature of the coating film formed by applying the liquid crystal aligning agent is not limited, and may be, for example, 100 to 350 ℃, preferably 120 to 300 ℃, and more preferably 150 to 250 ℃. The firing time may be set to any time from 5 to 240 minutes. Preferably 10 to 90 minutes, more preferably 20 to 90 minutes. The heating may be performed by a known method, for example, a hot plate, a hot air circulating furnace, an infrared furnace, or the like.

The thickness of the liquid crystal alignment film obtained by firing is not particularly limited, but is preferably 5 to 300nm, more preferably 10 to 120 nm.

< liquid Crystal display element >

The liquid crystal display element of the present invention can be obtained by forming a liquid crystal alignment film on a substrate by the above-described method and then fabricating a liquid crystal cell by a known method.

A specific example of the liquid crystal display element is a vertical alignment type liquid crystal display element including a liquid crystal cell having: 2 substrates disposed in an opposing manner, a liquid crystal layer provided between the substrates, and a liquid crystal alignment film provided between the substrates and the liquid crystal layer and formed of the liquid crystal alignment agent of the present invention. Specifically, the liquid crystal display element of the vertical alignment type is provided with a liquid crystal cell manufactured as follows: the liquid crystal cell is produced by applying the liquid crystal aligning agent of the present invention to 2 substrates, firing the liquid crystal aligning agent to form a liquid crystal alignment film, arranging the 2 substrates so that the liquid crystal alignment film faces each other, sandwiching a liquid crystal layer made of liquid crystal between the 2 substrates, providing the liquid crystal layer in contact with the liquid crystal alignment film, and irradiating ultraviolet rays while applying a voltage to the liquid crystal alignment film and the liquid crystal layer.

By using the liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention, the polymerizable compound is polymerized by irradiating ultraviolet rays while applying a voltage to the liquid crystal alignment film and the liquid crystal layer, and the photoreactive side chains in the polymer are reacted with each other, and the photoreactive side chains in the polymer are reacted with the polymerizable compound, whereby the alignment of the liquid crystal is more effectively fixed, and a liquid crystal display element having a remarkably excellent response speed is formed.

The substrate used in the liquid crystal display element of the present invention is not particularly limited as long as it is a substrate having high transparency, and is usually a substrate on which a transparent electrode for driving liquid crystal is formed. Specific examples thereof include the same substrates as those described in the liquid crystal alignment film.

The liquid crystal display element of the present invention can use a substrate provided with a conventional electrode pattern or protrusion pattern, but the liquid crystal alignment film formed by using the liquid crystal alignment agent of the present invention can be used even if a substrate having a structure in which a line/slit electrode pattern of 1 to 10 μm is formed on one side substrate and no slit pattern or protrusion pattern is formed on the opposite side substrate is used, and thus the process for manufacturing the liquid crystal display element can be simplified and high transmittance can be obtained.

In addition, in a high-functional element such as a TFT-type element, a product in which an element such as a transistor is formed between an electrode for driving liquid crystal and a substrate can be used.

In the case of a transmissive liquid crystal display element, the above-mentioned substrate is generally used, but in the case of a reflective liquid crystal display element, if only a single-sided substrate is used, an opaque substrate such as a silicon wafer may be used. In this case, a material such as aluminum that reflects light may be used for the electrodes formed on the substrate.

The liquid crystal alignment film is formed by coating the liquid crystal alignment agent of the present invention on the substrate and then firing the coated substrate, as described in detail above.

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited, and a liquid crystal material conventionally used in a vertical alignment system, for example, a negative type liquid crystal such as MLC-6608 or MLC-6609 manufactured by MERCK Corporation, can be used.

In order to produce the liquid crystal display element of the present invention, the polymerizable compound of the present invention may be contained in at least one of the liquid crystal aligning agent and the liquid crystal layer.

As a method of sandwiching the liquid crystal layer between 2 substrates, a known method can be mentioned. Examples of the method include the following methods: a method of preparing 1 pair of substrates on which liquid crystal alignment films are formed, spreading spacers such as beads on the liquid crystal alignment film of one substrate, attaching the other substrate so that the surface on which the liquid crystal alignment film is formed is the inside, injecting liquid crystal under reduced pressure, and sealing.

Further, a liquid crystal cell can also be produced by a method in which 1 pair of substrates on which liquid crystal alignment films are formed are prepared, spacers such as beads are scattered on the liquid crystal alignment film of one substrate, liquid crystal is dropped, and thereafter the other substrate is attached and sealed so that the surface on which the liquid crystal alignment films are formed is on the inside. The thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

Examples of the step of producing a liquid crystal cell by irradiating ultraviolet rays while applying a voltage to the liquid crystal alignment film and the liquid crystal layer include a method of applying an electric field to the liquid crystal alignment film and the liquid crystal layer by applying a voltage between electrodes provided on the substrates, and irradiating ultraviolet rays while maintaining the electric field. The voltage applied between the electrodes is, for example, 5 to 30Vp-p, preferably 5 to 20 Vp-p. The dose of the ultraviolet ray is, for example, 1 to 60J/cm²Preferably 40J/cm²The lower, more preferably 20J/cm²The following. The smaller the amount of ultraviolet irradiation, the more the reduction in reliability due to damage of the liquid crystal and parts constituting the liquid crystal display element can be suppressed, and the shorter the ultraviolet irradiation time, the more the manufacturing efficiency is improved, which is preferable.

The wavelength of the ultraviolet ray used is preferably 300 to 400nm, more preferably 310 to 370 nm.

When ultraviolet rays are irradiated to the liquid crystal alignment film and the liquid crystal layer while applying a voltage, the polymerizable compound reacts to form a polymer, and the polymer retains the tilt direction of the liquid crystal molecules, thereby increasing the response speed of the resulting liquid crystal display element.

Further, if ultraviolet rays are irradiated while applying a voltage to the liquid crystal alignment film and the liquid crystal layer, photoreactive side chains of at least 1 polymer selected from the group consisting of a polyimide precursor having a photoreactive side chain and a polyimide obtained by imidizing the polyimide precursor react with each other, and the photoreactive side chain of the polymer reacts with the polymerizable compound, so that the response speed of the resulting liquid crystal display element can be increased.

The liquid crystal aligning agent of the present invention is useful not only as a liquid crystal aligning agent for producing a liquid crystal display element of a vertical alignment system such as a PSA-type liquid crystal display or an SC-PVA-type liquid crystal display, but also suitably used for producing a liquid crystal alignment film formed by a rubbing treatment or a photo-alignment treatment.

Examples

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. The following compounds are abbreviated as follows.

BODA: bicyclo [3,3,0] octane-2, 4,6, 8-tetracarboxylic dianhydride.

CBDA: 1,2,3, 4-cyclobutanetetracarboxylic dianhydride.

And (3) PMDA: pyromellitic anhydride.

TCA: 2,3, 5-tricarboxycyclopentylacetic acid-1, 4,2, 3-dianhydride.

DBA: 3, 5-diaminobenzoic acid

NMP: n-methyl-2-pyrrolidone.

BCS: butyl cellosolve.

3AMP (3 AMP): 3-dimethylpyridine amine.

< Synthesis example 1>

< Synthesis of RM1-A >

20g (93.4mmol) of 4- (4-hydroxyphenyl) benzoic acid, 70.0g (3.5 wt%) of NMP, 38.7g (3.0eq) of potassium carbonate and 0.776g (5.0 mol%) of potassium iodide were put into a500 mL (mL) four-necked flask equipped with a magnetic stirrer at room temperature, and 10.0g (0.5 wt%) of NMP was added to the reaction mixture while cleaning the wall surface of the flask, followed by stirring. Thereafter, the temperature was raised to 100 ℃ to wash off the powder adhering to the wall surface of the flask, and 35.7g (2.5eq) of 4-chlorobutylaldehyde dimethyl acetal and 10.0g (0.5wt) of NMP were poured into the reaction system and stirred for 18 hours to effect reaction.

After the reaction, 120g (6.0wt) of toluene was added and filtered, and the filtrate was washed 2 times with 20.0g (1wt) of toluene. Next, the toluene filtrate was washed 3 times with 80.0g (4wt) of water. Thereafter, vacuum drying was performed at 50 ℃ and the solvent was distilled off. To the residue was added 30.0g (1.5 wt%) of ethyl acetate, and the mixture was heated to 50 ℃ to dissolve it. Thereafter, 140g (7wt) of heptane was added dropwise and cooled to 0 ℃. A small amount of seed crystals were added to precipitate crystals. The crystals were filtered, washed 2 times with heptane 20.0g (1wt), and then vacuum-dried at 30 ℃ to obtain RM 1-A38.0 g (yield: 91%, property: white solid).

< Synthesis of RM 1>

After 35.0g (78.4mmol) of RM1-A and 105g (3.0wt) of THF were put into a 1L four-necked flask equipped with a magnetic stirrer at room temperature and the solution was confirmed by stirring, 38.9g (2.2eq) of tin chloride dihydrate and 33.4g (2.2eq) of ethyl 2- (bromomethyl) acrylate were put into the flask in this order, and the temperature was raised to 60 ℃. Then, 125g (3.6wt) of 0.1M hydrochloric acid was added dropwise, and 245g (7wt) of THF was poured into the reaction system while washing off the powder attached to the wall surface of the flask, and the reaction was carried out under stirring for 14.5 hours.

The reaction solution was cooled to 50 ℃ and 350g (10wt) of toluene was added thereto to separate the solution, thereby removing a hydrochloric acid layer. Thereafter, the organic layer was added dropwise to 263g (7.5wt) of a 12.9 mass% potassium hydroxide aqueous solution at 50 ℃ over 30 minutes, followed by stirring, and then the organic layer was separated. To the obtained organic layer, 262g (7.5wt) of a 5.2 mass% potassium hydroxide aqueous solution was added and stirred, followed by liquid separation at 50 ℃. To the separated organic layer, 3.49g (10 wt%) of activated carbon was added, and the mixture was stirred at 50 ℃ for 30 minutes, followed by filtration at 50 ℃. The filtrate was washed 2 times with 17.5g (0.5wt) of toluene, and the total toluene filtrate was cooled to 5 ℃ with stirring and aged for 1 hour. The precipitated solid was collected by filtration, and the filtrate was washed 2 times with 17.5g (0.5wt) of heptane. The filtrate was vacuum-dried at 40 ℃ to obtain RM119.7g (yield: 51%, property: white crystals).

¹H-NMR (400MHz) in DMSO-d 6: 1.79-1.87ppm (m,8H),2.64ppm (dd, J ═ 7.4,18.6Hz,2H),3.10ppm (dd, J ═ 8.4.14.0Hz,2H),4.08ppm (t, J ═ 5.6Hz,2H),4.31ppm (t, J ═ 6.8Hz,2H),4.61-4.68ppm (m,2H),5.73ppm (s,2H),6.04ppm (d, J ═ 4.8Hz,2H),7.06ppm (d, J ═ 8.8Hz,2H),7.70ppm (d, J ═ 4.4Hz,2H),7.78ppm (d, J ═ 4.4Hz,2H),8.01ppm (d, J ═ 8.4, 2H).

< Synthesis example 2>

< Synthesis of RM2-A >

In a500 mL four-necked flask equipped with a magnetic stirrer, 80.0g (430mmol) of 4, 4' -biphenol and 160.0g (2.0wt) of DMF were put at room temperature and dissolved by stirring. Thereafter, 77.2g (1.3eq) of potassium carbonate and 3.57g (5.0 mol%) of potassium iodide were added in this order. Thereafter, the temperature was raised to 80 ℃ and 65.6g (1.0eq) of 4-chlorobutylaldehyde dimethyl acetal was added dropwise over 1 hour, followed by stirring for 19.5 hours to effect a reaction.

The reaction solution was added dropwise to 1600g (20wt) of water, followed by stirring for 0.5 hour, and the precipitated solid was collected by filtration. The filtrate was washed 2 times with 40.0g (0.5wt) of water. Thereafter, the filtrate was dried at 40 ℃ under reduced pressure for 1.5 hours. To the dried filtrate, 880g (11wt) of methanol was added, and the crystals were washed with stirring in a suspended state (hereinafter referred to as slurry washing), followed by filtration. The filtrate was washed 2 times with 8.00g (0.1wt) of methanol. The solvent in the filtrate such as methanol is distilled off under reduced pressure to obtain residue. The resulting residue was washed with 1040g (13wt) of chloroform and then filtered. The filtrate was washed 2 times with 16.0g (0.2wt) of chloroform, and the solvent in the chloroform filtrate was distilled off. 104g (1.3wt) of THF and 326g (4.1wt) of heptane were added to the resulting residue, which was cooled to 0 ℃ to conduct crystallization. To the precipitated solid, 400g (5wt) of methanol was added to conduct slurry washing, and filtered. The filtrate was dried under reduced pressure at 40 ℃ to obtain RM 2-A33.6 g (yield: 26%, property: white solid).

< Synthesis of RM2-B >

To a500 mL four-necked flask equipped with a magnetic stirrer, 33.6g (111mmol) of RM2-A and 169g (5wt) of DMF were placed at room temperature, and dissolved by stirring, and 20.0g (1.3eq) of potassium carbonate was added. Thereafter, the temperature was raised to 80 ℃, 25.6g (1.3eq) of 2- (4-bromobutyl) -1, 3-dioxolane was added dropwise, and the mixture was stirred for 24.5 hours to effect reaction.

The reaction mixture was added dropwise to 672g (20wt) of water, stirred for 0.5 hour, and the precipitated solid was collected by filtration. The filtrate was washed 2 times with 16.8g (0.5wt) of water. The filtrate was then dried under vacuum at 40 ℃ for 1.5 hours. 100g (3.0wt) of toluene was added to the dried filtrate, and the mixture was heated to 70 ℃ to dissolve the toluene. Thereafter, 198g (6.0 wt.) of heptane was added dropwise, cooled to 0 ℃ and the precipitated solid was collected by filtration. The resulting filtrate was washed 2 times with heptane 10.0g (0.3 wt). The filtrate was dried under vacuum at 40 ℃ to obtain RM2-B (yield: 75%, property: white solid) 35.6 g.

< Synthesis of RM 2>

50.0g (116mmol) of RM2-B and 500g (10wt) of THF were put into a 1L four-necked flask equipped with a magnetic stirrer at room temperature, stirred and dissolved, 57.7g (2.2eq) of tin chloride dihydrate and 49.3g (2.2eq) of ethyl 2- (bromomethyl) acrylate were put into the flask in this order, and the temperature was raised to 60 ℃. Thereafter, 179g (3.6wt) of 0.1M hydrochloric acid was added dropwise thereto, and the mixture was stirred for 26 hours to effect a reaction.

The reaction solution was cooled to 50 ℃ and 500g (10wt) of toluene was added thereto to separate the solution, thereby removing a hydrochloric acid layer. The organic layer was added dropwise over 30 minutes to 375g (7.5wt) of a 12.9 mass% aqueous potassium hydroxide solution at 50 ℃ and thereafter the organic layer was subjected to liquid separation. 375g (7.5wt) of a 5.2 mass% potassium hydroxide aqueous solution was added to the organic layer, and liquid separation was performed at 50 ℃. The separated organic layer was washed with 375g (7.5wt) of water. To the washed organic layer, 5.12g (10 wt%) of activated carbon was added, and after stirring at 50 ℃ for 30 minutes, filtration was performed at 50 ℃. The filtrate was washed 2 times with 25.0g (0.5wt) of toluene, and the total toluene filtrate was cooled to 5 ℃ with stirring and allowed to mature for 1 hour. The precipitated solid was collected by filtration, and the filtrate was washed 2 times with heptane 25.0g (0.5 wt). The filtrate was dried under vacuum at 40 ℃ to obtain RM235.6 g (yield: 83%, property: white crystals).

¹H-NMR (400MHz) in DMSO-d 6: 1.42-1.58ppm (m,2H),1.62-1.86ppm (m,8H),2.58-2.67ppm (m,2H),3.06-3.11ppm (m,2H),4.00-4.03ppm (m,4H),4.55-4.66ppm (m,2H),5.71ppm (s,1H),5.73ppm (s,1H),6.03ppm (s,1H),6.05ppm (s,1H),6.98ppm (d, J ═ 8.8Hz,4H),7.52ppm (d, J ═ 8.8Hz,4H).

< Synthesis example 3>

< Synthesis of RM3-A >

In a500 mL four-necked flask equipped with a magnetic stirrer, 50.0g (269mmol) of 4, 4' -biphenol and 175g of DMF were charged at room temperature and dissolved by stirring, and 48.24g (1.3eq) of potassium carbonate was added. Thereafter, the temperature was raised to 80 ℃ and 48.61g (1.0eq) of 2- (2-bromoethyl) -1, 3-dioxolane was added dropwise over 1 hour, followed by stirring for 7 hours to effect reaction. Subsequently, the reaction solution was added dropwise to 1000g of water, and after stirring at room temperature for 0.5 hour, the precipitated solid was collected by filtration. 550g of methanol was added to the filtrate, and after slurry washing at room temperature, the filtrate was filtered at 0 to 5 ℃. 650g of chloroform was added to the residue after the solvent in the filtrate was distilled off, and the slurry was washed at room temperature and then filtered. After 15g of THF was added to and dissolved in the residue after the solvent in the filtrate was distilled off, 37.5g of toluene was added, and the mixture was stirred in an ice bath for 0.5 hour. The precipitated crystals were collected by filtration, washed (toluene 12.5g), and dried under reduced pressure at 40 ℃ to obtain RM 3-A9.0 g (yield: 12%, property: gray crystals).

< Synthesis of RM3-B >

In a500 mL four-necked flask equipped with a magnetic stirrer, 8.31g (29mmol) of RM3-A and 12.5g of NMP were placed at room temperature, and stirred to dissolve them, and then 6.01g (1.5eq.) of potassium carbonate was added. Thereafter, the temperature was raised to 80 ℃ and 5.79g (1.1eq) of 2- (4-bromobutyl) -1, 3-dioxolane was added dropwise over 10 minutes, followed by stirring for 19 hours to effect a reaction. Then, 83g of ethyl acetate was added to the reaction solution, and the precipitated inorganic salt was filtered off. Then, the filtrate was subjected to 3 times of liquid separation washing with 24g of water, and the solvent in the filtrate was distilled off. To the resulting residue was added 24g of toluene, and after dissolving at 70 ℃, 48g of heptane was added, and the mixture was stirred in an ice bath for a while. The precipitated crystals were collected by filtration and dried at 40 ℃ under reduced pressure to obtain RM3-B (yield: 91%, property: white solid) 12.2 g.

< Synthesis of RM 3>

In a500 mL four-necked flask equipped with a magnetic stirrer, 11.0g (26.5mmol) of RM3-B and 110g of THF were placed at room temperature, and stirred to dissolve them, and then 14.4g (2.4eq) of tin chloride dihydrate and 49.3g (2.2eq) of ethyl 2- (bromomethyl) acrylate were added in this order. Thereafter, 38.5g of 10 mass% hydrochloric acid was added dropwise thereto, and the reaction was carried out for 120 hours. The reaction mixture was concentrated under reduced pressure to about one third, then cooled to 15 ℃ and the precipitated crystals were collected by filtration and washed (water 44g × 3 times). Then, the crystals were dissolved in 165g of THF, and 110g of toluene was added thereto and diluted. The resulting solution was added dropwise to 82.5g of a 12.9 mass% aqueous potassium hydroxide solution at room temperature, and the aqueous layer was separated and removed. To the obtained organic layer was added 82.5g of a 5.2 mass% aqueous potassium hydroxide solution at room temperature, and the aqueous layer was separated and removed. Thereafter, the organic layer was washed 5 times with 82.5g of water, and 0.55g (5 mass%) of a special aigrette of activated carbon was added thereto, followed by stirring at room temperature for 1 hour and filtration. Thereafter, the filtrate was concentrated under reduced pressure to about 15g, and stirred at 5 ℃ for a while. The precipitated crystals were collected by filtration, washed with heptane (5.5 g X2 times), and dried under reduced pressure at 40 ℃ to obtain RM37.1 g (yield: 53%, property: white crystals).

¹H-NMR (400MHz) in DMSO-d 6: 1.40-1.82ppm (m,6H),2.08-2.13ppm (m,2H),2.55-2.81ppm (m,2H),3.06-3.11ppm (m,2H),3.98-4.18ppm (m,4H),4.55-4.85ppm (m,2H),5.72ppm (d, J ═ 8.8Hz,2H),6.05ppm (d, J ═ 8.8Hz,2H),6.97-7.08ppm (m,4H),7.52-7.61ppm (m,4H).

< Synthesis example 4>

RM4 was synthesized according to the method disclosed in WO 2012/002513.

< Synthesis example 5>

RM5 was synthesized according to the method disclosed in Japanese patent application No. 2014-015830.

< Synthesis example 6>

< Synthesis of RM6-A >

55.8g (300mmol) of 4, 4' -biphenol, 62.7g (1.0eq) of 2- (4-bromobutyl) -1, 3-dioxolane and 234g (4.2wt) of acetone were sequentially charged into a 1L four-necked flask equipped with a magnetic stirrer at room temperature, 53.9g (1.3eq) of potassium carbonate was further added while stirring, and 156g (2.8wt) of acetone was poured into the reaction system while washing off the powder attached to the wall surface of the flask. Thereafter, the reaction mixture was heated to 60 ℃ and stirred for 41.5 hours.

Thereafter, it was naturally cooled to room temperature, and then the reaction solution was added dropwise to water 3013g (54wt), and stirred for 30 minutes. Then, the precipitated solid was collected by filtration, and the filtrate was dried at 30 ℃ under reduced pressure. To the dry solid was added 614g (11wt) of methanol and stirred, and slurry washing was performed. Thereafter, filtration was performed and the obtained filtrate was concentrated. To the resulting residue was added 725g (13wt) of chloroform and stirred, followed by slurry washing. Subsequently, the obtained filtrate was concentrated under reduced pressure. To the resulting residue was added 72.5g (1.3wt) of THF, and 273g (4.9wt) of heptane was further added dropwise, followed by cooling to 0 ℃. The precipitated solid was collected by filtration, washed with heptane, and dried under reduced pressure to obtain RM 6-A31.6 g (yield: 34%, property: white solid).

< Synthesis of RM6-B >

In a500 mL four-necked flask equipped with a magnetic stirrer, RM6-A19.7g (62.6mmol), potassium carbonate 43.1g (5.0eq), potassium iodide 1.04g (10 mol%) and DMF 148g (7.5wt) were put in this order at room temperature, and the temperature was raised to 100 ℃ with stirring. Further, 4.80g (1.8eq) of 4-chloro-1-butanol was added dropwise thereto and stirred for 27 hours to effect a reaction. In the course of the reaction, 2.40g (0.3eq) of 4-chloro-1-butanol was added 2 times because the reaction slowed down.

Thereafter, the reaction solution was filtered to remove potassium carbonate. The filtrate was concentrated to 4.3wt, and the residue was added dropwise to 400g (20wt) of water to precipitate crystals. To the resulting crystals were added 197g (10wt) of THF, dissolved at 40 ℃ and 197g (10wt) of heptane was added dropwise to precipitate crystals. Thereafter, the solution containing the crystals was cooled to 0 ℃ and then filtered, and the obtained crystals were dried under reduced pressure to obtain RM6-B19.4g (yield: 80%, property: light brown solid).

< Synthesis of RM6-C >

To 19.4g (50.3mmol) of RM6-B at room temperature was added 155g (8.0wt) of THF, and after confirming its dissolution under stirring, 55.4mg (0.5 mol%) of BHT, 20.4g (1.8eq) of stannic chloride dihydrate and 17.5g (1.8eq) of ethyl 2- (bromomethyl) acrylate were sequentially charged. Thereafter, the temperature was raised to 60 ℃ and 69.4g (3.6wt) of 0.1M hydrochloric acid was added dropwise thereto, followed by stirring for 18 hours to effect a reaction.

Then, the temperature was adjusted to 50 ℃, and 194g (10wt) of toluene was added thereto to separate the layers. The organic layer was added dropwise over 30 minutes to 150g (7.5wt) of a 12.9 mass% aqueous potassium hydroxide solution at 50 ℃ while insoluble matter was precipitated. Accordingly, 637g (32.8wt) of a 12.9 mass% potassium hydroxide aqueous solution was added to dissolve insoluble materials, and then liquid separation was performed at 50 ℃. Subsequently, the separated organic layer was washed with 150g (7.5wt) of a 5.2 mass% aqueous potassium hydroxide solution, and further washed with 150g (7.5wt) of water. To the washed organic layer was added 2.00g of activated carbon (purpose-made aigret, 10 wt%), and the mixture was stirred at 50 ℃ for 30 minutes and then filtered while hot. The filtrate was washed 2 times with 10.5g (0.5wt) of toluene and the total filtrate was aged at 5 ℃ for 30 minutes. Thereafter, the precipitated solid was collected by filtration and washed 2 times with 10.5g (0.5wt) of heptane. The obtained solid was dried under reduced pressure at 40 ℃ to obtain RM 6-C3.2 g (yield: 16%, property: white solid).

< Synthesis of RM 6>

RM 6-C3.1 g (7.5mmol) was put into a500 mL four-necked flask equipped with a magnetic stirrer at room temperature, 308g (100wt) of THF was added, and dissolution was confirmed with stirring. Thereafter, 10.3g (13.6eq.) of triethylamine and 10.2g (13 eq.) of methacryloyl chloride were added dropwise over 1 hour, and the mixture was stirred for 19.5 hours to react.

Then, 217g (70wt) of water was added to dissolve triethylamine hydrochloride, and 208g (67wt) of toluene was further added to separate the solution. The separated organic layer was washed 2 times with 151g (49wt) of water. Thereafter, in order to avoid the occurrence of polymerization reaction, distillation was carried out under reduced pressure at 25 ℃ until the amount of the solvent reached 10g (3.3 wt%). To the resulting residue, 40.3g (13wt) of heptane was added dropwise, followed by aging at 0 ℃ for 1 hour. The precipitated solid was collected by filtration and washed 2 times with 9.3g (3.0 wt.) of heptane. The obtained solid was dried under vacuum at 25 ℃ to obtain RM62.4g (yield: 67%, property: white crystals).

¹H-NMR (400MHz) in DMSO-d 6: 1.42-1.84ppm (m,10H),1.88ppm (s,3H),2.60ppm (dd, J ═ 6.0,17.2Hz,1H),3.10ppm (dd, J ═ 8.0,17.2Hz,1H),3.99-4.00ppm (m,4H),4.17ppm (t, J ═ 6.0Hz,2H),4.59ppm (quant, J ═ 6.0Hz,1H),5.69ppm (d, J ═ 16.4Hz,2H),6.03ppm (s,2H),6.97ppm (d, J ═ 6.0Hz,4H),7.51ppm (d, J ═ 8.0Hz,4H).

The hydrogen nuclear magnetic resonance (f) of the synthesis example¹HNMR) was measured in a deuterated dimethyl sulfoxide (DMSO-d6) solvent using an NMR measuring instrument (JNW-ECA 500, manufactured by japan electronics データム corporation), and the chemical shift was represented by a δ value (ppm) when tetramethylsilane was used as an internal standard.

< measurement of polyimide molecular weight >

The device comprises the following steps: センシュー Normal temperature Gel Permeation Chromatography (GPC) device (SSC-7200) manufactured by science corporation,

Column: columns (KD-803, KD-805) manufactured by Shodex,

Column temperature: at 50 deg.C,

Eluent: n, N' -dimethylformamide (as additive, lithium bromide monohydrate (LiBr. H)₂O) is 30mmol/L, phosphoric acid30mmol/L of anhydrous crystals (orthophosphoric acid) and 10ml/L of Tetrahydrofuran (THF),

Flow rate: 1.0 ml/min,

Standard sample for standard curve preparation: TSK standard polyethylene oxides (molecular weights of about 9000,000, 150,000, 100,000 and 30,000) manufactured by Tosoh corporation and polyethylene glycols (molecular weights of about 12,000, 4,000 and 1,000) manufactured by Polymer Laboratories Ltd.

< measurement of imidization Rate >

20mg of polyimide powder was put into an NMR sample tube (NMR sample tube Standard. phi.5, manufactured by Softweed scientific Co., Ltd.), and deuterated dimethyl sulfoxide (DMSO-d) was added thereto₆0.05 mass% TMS mixture) 1.0ml was completely dissolved with ultrasonic waves. The solution was subjected to proton NMR measurement at 500MHz using an NMR measuring apparatus (JNW-ECA 500 manufactured by JEOL データム Co.). The imidization ratio is determined using a proton derived from a structure which does not change before and after imidization as a reference proton, and the peak integrated value of the proton derived from an NH group of amic acid appearing in the vicinity of 9.5 to 10.0ppm are obtained by the following equation. In the following formula, x represents a peak integrated value of a proton derived from the NH group of amic acid, y represents a peak integrated value of a reference proton, and α represents a number ratio of 1 proton of the reference proton to the NH group of amic acid when polyamic acid (imidization ratio of 0%) is used.

Imidization ratio (%) - (1-. alpha.x/y). times.100

< Synthesis example 7>

BODA (10.0g, 40.0mmol), DA-1(15.2g, 40.0mmol), DA-2(4.85g, 20.0mmol) and DA-3(13.2g, 40.0mmol) were dissolved in NMP (164.4g) and reacted at 60 ℃ for 3 hours. Subsequently, CBDA (11.5g, 58.6mmol) and NMP (54.8g) were added thereto, and the mixture was reacted at 40 ℃ for 10 hours to obtain a polyamic acid solution.

To the polyamic acid solution (250g) was added NMP and diluted to 6.5 mass%, and then acetic anhydride (46.4g) and pyridine (14.4g) as imidization catalysts were added and reacted at 70 ℃ for 3 hours. The reaction solution was poured into methanol (2900g), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder a. The polyimide had an imidization ratio of 73%, Mn of 13000 and Mw of 39000.

To the obtained polyimide powder A (10.0g), NMP (48.8g) was added and dissolved by stirring at 70 ℃ for 12 hours. To the solution were added 10.0g of 3AMP (1 wt% NMP solution), NMP (31.2g) and BCS (66.7g), and stirred at room temperature for 5 hours, thereby obtaining a liquid crystal aligning agent A1.

< Synthesis example 8>

BODA (18.0g, 72.0mmol), DA-1(13.7g, 36.0mmol), DA-2(8.72g, 36.0mmol) and DBA (7.30g, 48.0mmol) were dissolved in NMP (173.5g) and reacted at 60 ℃ for 3 hours. Thereafter, PMDA (10.1g, 46.3mmol) and NMP (57.8g) were added thereto, and the mixture was reacted at room temperature for 10 hours to obtain a polyamic acid solution.

To the polyamic acid solution (250g) was added NMP and diluted to 10 mass%, and then acetic anhydride (52.6g) and pyridine (40.8g) as imidization catalysts were added and reacted at 80 ℃ for 4 hours. The reaction solution was poured into methanol (2900g), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder B. The polyimide had an imidization ratio of 77%, Mn of 12000 and Mw of 35000. A liquid crystal aligning agent B1 was obtained in the same manner as in Synthesis example 7, except that polyimide powder B (10.0g) was used in place of polyimide powder A.

< Synthesis example 9>

Liquid crystal aligning agent C1 was obtained by adding 130.0 g of liquid crystal aligning agent b130.0 g obtained in synthesis example 8 to 170.0 g of liquid crystal aligning agent a170 obtained in synthesis example 7 and stirring at room temperature for 5 hours.

< Synthesis example 10>

BODA (6.51g, 26.0mmol), DA-1(14.8g, 38.9mmol) and DBA (13.9g, 91.0mmol) were dissolved in NMP (165.3g) and reacted at 60 ℃ for 3 hours. Thereafter, CBDA (19.9g, 101.5mmol) and NMP (55.1g) were added thereto, and the mixture was reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

NMP was added to the polyamic acid solution (250g) to dilute the solution to 6.5 mass%, and acetic anhydride (59.7g) and pyridine (18.5g) were added as imidization catalysts to react at 50 ℃ for 3 hours. The reaction solution was poured into methanol (2900g), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder D. The polyimide had an imidization ratio of 75%, Mn of 12000 and Mw of 32000. A liquid crystal aligning agent D1 was obtained in the same manner as in Synthesis example 7, except that polyimide powder D (10.0g) was used in place of polyimide powder A.

< Synthesis example 11>

Liquid crystal aligning agent E1 was obtained by adding D130.0 g of liquid crystal aligning agent obtained in Synthesis example 10 to 170.0 g of liquid crystal aligning agent obtained in Synthesis example 7 and stirring at room temperature for 5 hours.

< Synthesis example 12>

BODA (10.0g, 40.0mmol), DA-1(19.0g, 50.0mmol) and DA-3(16.5g, 50.0mmol) were dissolved in NMP (171.1g) and reacted at 60 ℃ for 3 hours. Thereafter, CBDA (11.5g, 58.6mmol) and NMP (57.0g) were added thereto, and the mixture was reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

NMP was added to the polyamic acid solution (250g) to dilute the solution to 6.5 mass%, and acetic anhydride (44.5g) and pyridine (13.8g) were added as imidization catalysts to react at 70 ℃ for 3 hours. The reaction solution was poured into methanol (2900g), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder F. The polyimide had an imidization ratio of 73%, Mn of 14000 and Mw of 38000. A liquid crystal aligning agent F1 was obtained in the same manner as in Synthesis example 7, except that polyimide powder F (10.0g) was used in place of polyimide powder A.

< Synthesis example 13>

Liquid crystal aligning agent G1 was obtained by adding 130.0G of liquid crystal aligning agent b130.0G obtained in synthesis example 8 to 170.0G of liquid crystal aligning agent f170 obtained in synthesis example 12 and stirring at room temperature for 5 hours.

< Synthesis example 14>

BODA (10.0g, 40.0mmol), DA-1(15.2g, 40.0mmol), DA-3(9.91g, 30.0mmol) and DA-5(7.93g, 30.0mmol) were dissolved in NMP (163.7g) and reacted at 60 ℃ for 3 hours. Thereafter, CBDA (11.5g, 58.6mmol) and NMP (54.6g) were added thereto, and the mixture was reacted at 40 ℃ for 10 hours to obtain a polyamic acid solution.

NMP was added to the polyamic acid solution (250g) to dilute the solution to 6.5 mass%, and acetic anhydride (46.5g) and pyridine (14.4g) were added as imidization catalysts to react at 70 ℃ for 3 hours. The reaction solution was poured into methanol (2900g), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder H. The polyimide had an imidization ratio of 74%, Mn of 16000 and Mw of 45000. A liquid crystal aligning agent H1 was obtained in the same manner as in Synthesis example 7, except that polyimide powder H (10.0g) was used in place of polyimide powder A.

< Synthesis example 15>

TCA (1.35g, 6.0mmol), DA-1(2.28g, 6.0mmol) and DA-3(2.97g, 9.0mmol) were dissolved in NMP (24.9g) and reacted at 80 ℃ for 3 hours. Thereafter, CBDA (1.74g, 8.9mmol) and NMP (8.3g) were added thereto, and the mixture was reacted at room temperature for 10 hours to obtain a polyamic acid solution.

NMP was added to the polyamic acid solution (36g) to dilute the solution to 6 mass%, and acetic anhydride (4.0g) and pyridine (2.1g) were added as imidization catalysts to react at 50 ℃ for 3 hours. The reaction solution was poured into methanol (700ml), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder I. The polyimide had an imidization ratio of 60%, Mn of 20000 and Mw of 43000.

To the obtained polyimide powder I (6.0g), NMP (44.0g) was added and the mixture was stirred at 50 ℃ for 5 hours to dissolve the polyimide powder I. To the solution were added 6.0g of 3AMP (1 wt% NMP solution), NMP (14.0g) and BCS (30.0g), and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal aligning agent I1.

< Synthesis example 16>

BODA (2.00g, 8.0mmol), DA-3(4.63g, 14.0mmol) and DA-4(2.61g, 6.0mmol) were dissolved in NMP (34.5g) and reacted at 60 ℃ for 3 hours. Thereafter, CBDA (2.27g, 11.6mmol) and NMP (11.5g) were added thereto, and the mixture was reacted at room temperature for 10 hours to obtain a polyamic acid solution.

NMP was added to the polyamic acid solution (50g) to dilute the solution to 6 mass%, and acetic anhydride (5.3g) and pyridine (2.7g) were added as imidization catalysts to react at 50 ℃ for 3 hours. The reaction solution was poured into methanol (700ml), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder J. The polyimide had an imidization ratio of 60%, Mn of 17000 and Mw of 35000. A liquid crystal aligning agent J1 was obtained in the same manner as in synthesis example 15, except that polyimide powder J (10.0g) was used in place of polyimide powder I.

< Synthesis example 17>

BODA (1.30g, 5.2mmol), DA-6(2.03g, 3.9mmol) and DA-3(3.00g, 9.1mmol) were dissolved in NMP (23.5g) and reacted at 60 ℃ for 3 hours. Thereafter, CBDA (1.43g, 7.3mmol) and NMP (7.8g) were added thereto, and the mixture was reacted at room temperature for 10 hours to obtain a polyamic acid solution.

To the polyamic acid solution (36g) was added NMP and diluted to 6 mass%, and then acetic anhydride (3.6g) and pyridine (1.9g) as imidization catalysts were added and reacted at 50 ℃ for 3 hours. The reaction solution was poured into methanol (700ml), and the resulting precipitate was collected by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain polyimide powder K. The polyimide had an imidization ratio of 60%, Mn of 16000 and Mw of 36000. A liquid crystal aligning agent K1 was obtained in the same manner as in synthesis example 15, except that polyimide powder K (10.0g) was used in place of polyimide powder I.

(example 1)

The polymerizable compound rm10.042g (7% by mass based on the solid content) obtained in synthesis example 1 was added to 110.0 g of the liquid crystal aligning agent c obtained in synthesis example 9, and stirred at room temperature for 3 hours to dissolve it, thereby preparing a liquid crystal aligning agent L1.

(example 2)

A liquid crystal aligning agent L2 was prepared in the same manner as in example 1, except that the amount of the polymerizable compound RM1 was changed to 0.06g (10 mass% based on the solid content).

(example 3)

A liquid crystal aligning agent L3 was prepared by the same method as in example 1, except that RM2 obtained in synthesis example 2 was used instead of the polymerizable compound RM 1.

(example 4)

A liquid crystal aligning agent L4 was prepared by the same method as in example 1, except that RM3 obtained in synthesis example 3 was used instead of the polymerizable compound RM 1.

(example 5)

A liquid crystal aligning agent M1 was prepared by the same method as in example 1, except that the liquid crystal aligning agent a1 obtained in synthesis example 7 was used instead of the liquid crystal aligning agent C1.

(example 6)

A liquid crystal aligning agent N1 was prepared by the same method as in example 1, except that the liquid crystal aligning agent E1 obtained in synthesis example 11 was used instead of the liquid crystal aligning agent C1.

(example 7)

A liquid crystal aligning agent O1 was prepared by the same method as in example 1, except that the liquid crystal aligning agent G1 obtained in synthesis example 13 was used instead of the liquid crystal aligning agent C1.

(example 8)

A liquid crystal aligning agent P1 was prepared by the same method as in example 1, except that the liquid crystal aligning agent H1 obtained in synthesis example 14 was used instead of the liquid crystal aligning agent C1.

(example 9)

A liquid crystal aligning agent Q1 was prepared by the same method as in example 1, except that the liquid crystal aligning agent I1 obtained in synthesis example 15 was used instead of the liquid crystal aligning agent C1.

(example 10)

A liquid crystal aligning agent R1 was prepared by the same method as in example 1, except that the liquid crystal aligning agent J1 obtained in synthesis example 16 was used instead of the liquid crystal aligning agent C1.

(example 11)

A liquid crystal aligning agent S1 was prepared by the same method as in example 1, except that the liquid crystal aligning agent K1 obtained in synthesis example 17 was used instead of the liquid crystal aligning agent C1.

Comparative example 1

A liquid crystal aligning agent L5 was prepared by the same method as in example 1, except that RM4 obtained in synthesis example 4 was used instead of the polymerizable compound RM 1.

Comparative example 2

A liquid crystal aligning agent L6 was prepared by the same method as in example 1, except that RM5 obtained in synthesis example 5 was used instead of the polymerizable compound RM 1.

Comparative example 3

A liquid crystal aligning agent L7 was prepared by the same method as in example 2, except that RM5 obtained in synthesis example 5 was used instead of the polymerizable compound RM 1.

Comparative example 4

A liquid crystal aligning agent L8 was prepared by the same method as in example 1, except that RM6 obtained in synthesis example 6 was used instead of the polymerizable compound RM 1.

Comparative example 5

A liquid crystal aligning agent L9 was prepared by the same method as in example 2, except that RM6 obtained in synthesis example 6 was used instead of the polymerizable compound RM 1.

< preparation of liquid Crystal cell >

(example 12)

A liquid crystal cell was produced by the following procedure using the liquid crystal aligning agent L1 obtained in example 1.

The liquid crystal aligning agent L1 was spin-coated on the IZO surface of the four-pixel IZO electrode substrate on which IZO electrode patterns (fish bones) having pixel sizes of 87 μm × 89 μm and line/space of 3 μm each were formed, and dried with a hot plate at 80 ℃ for 90 seconds. Thereafter, the resultant was baked in a hot air circulating oven at 200 ℃ for 20 minutes to form a liquid crystal alignment film having a film thickness of 100 nm.

Further, a liquid crystal aligning agent L1 was spin-coated on the ITO surface of the ITO electrode substrate on which no electrode pattern was formed, and dried for 90 seconds with a hot plate at 80 ℃. Thereafter, the resultant was baked in a hot air circulating oven at 200 ℃ for 20 minutes to form a liquid crystal alignment film having a film thickness of 100 nm.

For the above 2 substrates, after spreading 3.3 μm bead spacers on the liquid crystal alignment film of one substrate, a sealant (solvent-type thermosetting epoxy resin) was printed thereon. Next, the other substrate is bonded to the former substrate with the surface of the other substrate on which the liquid crystal alignment film is formed as the inner side, and then the sealant is cured to produce an empty cell. Liquid crystal MLC-6608 (manufactured by MERCK Corporation) was injected into the empty cell by a reduced pressure injection method. Thereafter, the resultant was left to stand in a hot air circulating oven at 120 ℃ for 1 hour to perform a liquid crystal realignment treatment, thereby producing a liquid crystal cell 1.

"Observation of bright spots in liquid crystal cell"

The bright point in the resulting liquid crystal cell 1 was observed by the following method. The liquid crystal cell 1 immediately after the above-described reorientation treatment was left at room temperature for 2 days, and thereafter, polarization microscope observation of the liquid crystal cell was performed. It can be considered that: when the solubility of the polymerizable compound in the liquid crystal is low, the polymerizable compound is likely to precipitate in the liquid crystal cell to generate a bright point. When no bright point is generated, the image is regarded as good, and when a bright point is generated, the image is regarded as bad.

Evaluation of residual image derived from AC "

The residual image derived from AC of the obtained liquid crystal cell 1 was measured by the following method.

Under the condition that DC voltage of 15V is applied to the liquid crystal cell 1, 6J/cm of the DC voltage is irradiated from the outside of the liquid crystal cell 1²UV passed through a band pass filter of 365 nm. The illuminance of UV was measured using UV-MO3A manufactured by ORC. Thereafter, Toshiba Lighting was used in a state where no voltage was applied&UV-FL irradiation apparatus manufactured by Technology Corporation, UV (UV lamp: FLR40SUV32/A-1) for 30 minutes. On both surfaces of the liquid crystal cell 1, polarizing films are attached in a crossed nicol state so that the polarizing axis of the polarizing film and the director of the liquid crystal are at 45 °. Of the 4 pixels, only 1 pixel and 1 pixel located at the opposite corner thereof are subjected toA rectangular wave of 30Hz and 20Vpp was applied for 70 hours. After the voltage is cut off, the electrodes of the liquid crystal cells are connected to each other to short-circuit them. Thereafter, the liquid crystal cell was placed on a backlight, and the luminance of the pixel to which the voltage was applied was compared with that of the pixel to which the voltage was not applied by visual observation. It can be considered that: when the image sticking characteristics are good, the luminance difference between the pixel to which the voltage is applied and the pixel to which the voltage is not applied becomes small, and when the luminance difference is not observed from the front view means, the image is regarded as good, and when the luminance difference is observed, the image is regarded as bad.

Measurement of Pre-Tilt Angle "

In the production of the liquid crystal cell 1, the liquid crystal cell 2 was produced in the same manner as in the production of the liquid crystal cell 1 except that an ITO electrode substrate on which an ITO electrode pattern having a pixel size of 100 μm × 300 μm and a line/space of 5 μm each was formed was used instead of the four-pixel IZO electrode substrate and a 4 μm bead spacer was used instead of the 3.3 μm bead spacer.

The resultant liquid crystal cell 2 was irradiated with a DC voltage of 15V from the outside of the liquid crystal cell 2²UV passed through a band pass filter of 365 nm. The illuminance of UV was measured using UV-MO3A manufactured by ORC. Thereafter, a UV-FL irradiation apparatus (Toshiba Lighting) was used in a state where no voltage was applied&Technology Corporation), UV (UV lamp: FLR40SUV 32/A-1).

The pretilt angle of the pixel portion after UV irradiation was measured using an LCD analyzer LCA-LUV42A (manufactured by Mitsubishi テクニカ).

(examples 13 to 22, comparative examples 6 to 10)

Liquid crystal cells were produced in the same manner as in example 12 except that the liquid crystal aligning agents L1 were replaced with the liquid crystal aligning agents shown in table 2, and the above-described evaluation was performed for each liquid crystal cell. The results are summarized in table 2.

[ Table 2]

The bright point observation results of examples 12 to 15 and comparative example 6 show that: by making the molecular structure of the polymerizable compound used asymmetric, the solubility in the liquid crystal is improved.

Furthermore, from the comparison of examples 12, 14, 15 with comparative examples 7 and 8: the method of making the molecular structure of the polymerizable compound asymmetric (methods 1 and 2) of the present invention has superior afterimage characteristics derived from AC, compared to the method of introducing a substituent in such a manner that the benzene ring is asymmetric to the left or right (method 4).

Similarly, from the results of examples 12, 14 and 15 and comparative examples 9 and 10: the method of making the molecular structure of the polymerizable compound asymmetric according to the present invention has superior afterimage characteristics derived from AC, compared to the method (method 3) in which the left and right polymerizable groups are different.

This is considered because: since the stacking of the ring structures is stronger than that of a methacryl compound in which one side of the polymerizable group is not a ring structure, the network of the resulting polymer becomes stiffer.

Industrial applicability

The liquid crystal display element having a liquid crystal alignment film formed using the liquid crystal aligning agent of the present invention has a high liquid crystal response speed, and is widely used as a liquid crystal display element of a vertical alignment system such as a PSA type liquid crystal display.

The entire contents of the specification, claims and abstract of japanese patent application 2015-22123 filed on 6/2/2015 are incorporated herein as the disclosure of the present invention specification.

Claims

1. A liquid crystal aligning agent comprising: a polymerizable compound (1) represented by the following formula (1) and at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide,

in the formula, X¹And X²Each independently represents a linking group selected from an ether bond and an ester bond; s¹And S²Each independently represents a linear alkylene group having 2 to 9 carbon atoms; and, S¹、X¹、X²And S²Selecting in a left-right asymmetric mode of molecules;

in the polymerizable compound (1), X¹And X²One of them is an ether bond and the other is an ester bond; or, X¹Is at the carbonyl side with S¹Bonded ester bond, X²Is on the oxygen atom side with S²A bonded ester bond.

2. The liquid crystal aligning agent according to claim 1, wherein S is contained in the polymerizable compound (1)¹And S²Are alkylene groups having different carbon numbers from each other.

3. The liquid crystal aligning agent according to claim 1 or 2, wherein at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide has a side chain for homeotropically aligning liquid crystals.

4. The liquid crystal aligning agent according to claim 3, wherein at least 1 polymer selected from the group consisting of polyimide precursors and polyimides further has a photoreactive side chain.

5. A liquid crystal alignment film formed by using the liquid crystal aligning agent according to any one of claims 1 to 4.

6. A liquid crystal display element having the liquid crystal alignment film according to claim 5.

7. A method for manufacturing a liquid crystal display element of a vertical alignment type, comprising:

applying a liquid crystal alignment agent containing at least 1 polymer selected from the group consisting of polyimide precursors and polyimides onto 2 substrates to form liquid crystal alignment layers, arranging the 2 substrates so that the liquid crystal alignment layers face each other, sandwiching the liquid crystal layer between the 2 substrates, and irradiating ultraviolet rays while applying a voltage to the liquid crystal alignment layer and the liquid crystal layer;

at least one of the liquid crystal aligning agent and the liquid crystal layer contains a polymerizable compound represented by the formula (1),

8. The production method according to claim 7, wherein S is S in the polymerizable compound (1)¹And S²Are alkylene groups having different carbon numbers from each other.

9. The manufacturing method according to claim 7 or 8, wherein at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide has a side chain for vertically aligning liquid crystals.

10. The production method according to claim 9, wherein at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide has a photoreactive side chain.

11. A polymerizable compound represented by the following formula (1),

wherein, X¹And X²One of them is an ether bond and the other is an ester bond; or, X¹Is at the carbonyl side with S¹Bonded ester bond, X²Is on the oxygen atom side with S²A bonded ester bond.

12. The polymerizable compound according to claim 11, wherein S in the formula (1)¹And S²Are alkylene groups having different carbon numbers from each other.