TW201920360A - Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal display device using same, and method for producing said liquid crystal alignment film - Google Patents

Abstract

This liquid crystal aligning agent contains: a polyimide precursor which is obtained from a diamine component containing a diamine having a structure represented by formula (1) and a diamine having a prescribed side chain structure; and/or a polyimide polymer that is an imidation product of said polyimide precursor. (In formula (1), A1 and A5 each independently denote a single bond or an alkylene group having 1-5 carbon atoms. A2 and A4 each independently denote an alkylene group having 1-5 carbon atoms. A3 denotes an alkylene group having 1-6 carbon atoms or a cycloalkylene group. B1 and B2 each independently denote a single bond, -O-, -NH-, -N(CH3)-, -CO-, -COO-, -OCO-, -CONH-, -NHCO-, -CON(CH3)- or -N(CH3)CO-. D1 denotes a protecting group. a is 0 or 1. * denotes the site of bonding to another group).

Description

Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal display element using the same, and manufacturing method of the liquid crystal alignment film

The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, a liquid crystal display element using the same, and a method for manufacturing the liquid crystal alignment film. In particular, it relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a method for manufacturing the liquid crystal display element and the liquid crystal alignment film using the VA-type liquid crystal display element suitable for responding to liquid crystal molecules vertically aligned to a substrate by an electric field.

Liquid crystal display devices are widely used in personal computers, mobile phones, smart phones, and televisions. In recent years, there are many opportunities for using liquid crystal display elements in high-temperature and high-humidity displays such as car navigation or meters mounted on vehicles, and display units of industrial equipment or measuring equipment installed outdoors.

Such a liquid crystal display element generally includes a liquid crystal layer held between an element substrate and a color filter substrate, a pixel electrode and a common electrode that apply an electric field to the liquid crystal layer, and a liquid crystal alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer. , A thin film transistor (TFT), etc., which switches an electrical signal supplied to a pixel electrode.

In a liquid crystal display element, a pixel electrode and a common electrode holding a liquid crystal layer function as a liquid crystal cell. When the liquid crystal cell has a low voltage holding ratio (VHR: Voltage Holding Ratio), it is difficult to apply a sufficient voltage to the liquid crystal molecules even when a voltage is applied. Therefore, due to use under high temperature, high humidity, or long-term use, the display contrast is reduced or a flicker is generated on the display, making the display difficult to view.

One of the driving methods of such a liquid crystal display element is a method (also referred to as a vertical alignment (VA) method) in which liquid crystal molecules aligned vertically to a substrate are responded by an electric field. In the liquid crystal display element of the vertical alignment method, a photopolymerizable compound is added to the liquid crystal composition in advance, and a vertical alignment film such as a polyimide system is used. The liquid crystal is irradiated with ultraviolet rays while applying a voltage to the liquid crystal cell. A technology (PSA (Polymer Sustained Alignment) system) that has a faster response speed (see, for example, Patent Literature 1 and Non-Patent Literature 1). Is known. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-307720 [Non-Patent Document]

[Non-Patent Document 1] K. Hanaoka, SID 04 DIGEST, P1200-1202

[Problems to be Solved by the Invention]

However, in recent years, with the increase in the performance of liquid crystal display elements, the characteristics expected from liquid crystal alignment films have become severe. Therefore, it has been difficult for the conventional technology to meet expectations for the characteristics of liquid crystal alignment films or liquid crystal display elements that have been accompanied by higher performance in recent years.

The present invention has been made in view of the above, and an object of the present invention is to provide a liquid crystal alignment agent capable of obtaining a liquid crystal alignment film that ensures a high voltage retention rate even under a high temperature and high humidity for a long time, the liquid crystal alignment film, and the use thereof A liquid crystal display element and a method for manufacturing the liquid crystal alignment film. [Means to solve the problem]

An aspect of the present invention that solves the above-mentioned problems is a liquid crystal alignment agent comprising: a diamine having a structure having the following formula (1); and a group selected from the group consisting of the following formulas [S1] to [S3] A diamine component of at least one type of diamine in the side chain structure of the group, and a polyimide precursor obtained from a tetracarboxylic acid component (including a tetracarboxylic acid derivative component) and / or a polyimide precursor Polyimide polymer of sulfonium imide.

(In formula (1), A ¹ and A ⁵ each independently represent a single bond or an alkylene group having 1 to 5 carbon atoms. A ² and A ⁴ each independently represent an alkylene group having 1 to 5 carbon atoms. A ³ represents carbon An alkylene or cycloalkylene having a number of 1 to 6. B ¹ and B ² each independently represent a single bond, -O-, -NH-, -N (CH ₃ )-, -CO-, -COO-,- OCO-, -CONH-, -NHCO-, -CON (CH ₃ )-or -N (CH ₃ ) CO-. D ₁ represents a protecting group substituted by a hydrogen atom by heat. A is 0 or 1. A ² And A ³ (when a is 1), A ³ and A ⁴ (when a is 1), or A ² and A ⁴ (when a is 0), they are not bonded to each other, and * indicates a part bonded to another base ).

(In the formula [S1], X ¹ and X ² each independently represent a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH ₃ )- , -NH-, -O -, - COO -, - OCO- , or _{- ((CH 2) a1 -A} 1) m1 -. wherein a plurality of a1 are each independently an integer of 1 to 15, a plurality of A ₁ each Independently represents an oxygen atom or -COO-; m ₁ is 1 to 2. G ¹ and G ² each independently represent a divalent aromatic group selected from a carbon number of 6 to 12 or a divalent alicyclic group of 3 to 8 carbons A divalent cyclic group of the formula group, and any hydrogen atom on the aforementioned cyclic group may be selected from the group consisting of an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and 1 to 3 carbon atoms. Substituted by at least one of the group consisting of a fluoroalkyl group, a fluorine-containing alkoxy group having 1 to 3 carbon atoms or a fluorine atom. M and n are each independently an integer of 0 to 3, and the total of m and n is 1 to 4. R ¹ represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxy alkyl group having 2 to 20 carbon atoms, and any hydrogen that forms R ¹ may be substituted by fluorine).

(In formula [S2], X ³ represents a single bond, -CONH-, -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO-, or -OCO- R ² represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, and any hydrogen that forms R ² may be substituted with fluorine).

(In the formula [S3], X ⁴ represents -CONH-, -NHCO-, -O-, -COO-, or -OCO-. R ³ represents a structure having a steroid skeleton).

Here, it is preferable that the diamine having the structure represented by the formula (1) has a structure represented by the following formula (1 ").

The diamine having the structure of the formula (1) is preferably at least one of the groups represented by the following formulae (1-1) to (1-18).

The diamine component is preferably a diamine having a side chain structure represented by the formula [S1].

The diamine having a side chain structure represented by the aforementioned formula [S1] is preferably at least one of the groups represented by the following formulas [S1-x1] to [S1-x7].

(In the formulas [S1-x1] to [S1-x7], R ¹ is the same as that in the formula [S1], and X ^p represents-(CH ₂ ) _a- (a is an integer from 1 to 15), -CONH- , -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO-, or -OCO-. A ₁ represents an oxygen atom or -COO- * (with "* "" Is bonded to (CH ₂ ) _a2 ). A ₂ represents an oxygen atom or * -COO- (a bond with "*" is bonded to (CH ₂ ) _a2 ). A ₁ is 0 or An integer of 1 and a ₂ being an integer of 2 to 10. Cy represents 1,4-cyclohexyl or 1,4-phenylene).

R ^{2 in} the diamine having a side chain structure represented by the aforementioned formula [S2] is preferably an alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms.

The diamine having a side chain structure represented by the aforementioned formula [S3] is preferably a diamine represented by the following formula [S3-x].

(In formula [S3-x], X represents formula [X1] or [X2]. In addition, Col represents at least one selected from the group consisting of formulas [Col1] to [Col4], and G represents formula [G1] Or [G2]. * Indicates a part bonded to another base).

The diamine component preferably contains a diside chain diamine having a structure of the following formula [1].

(In the formula [1], X represents a single bond, -O-, -C (CH ₃ ) _2- , -NH-, -CO-,-(CH ₂ ) _m- , -SO ₂ -and any of them The divalent organic group formed by the combination. M is an integer of 1 to 8. Each of two Y independently represents at least one side chain structure selected from the group represented by the aforementioned formulas [S1] to [S3].

In addition, another aspect of the present invention that solves the above-mentioned problems is a liquid crystal alignment film formed by using the liquid crystal alignment agent described in any one of the above.

In addition, another aspect of the present invention that solves the above problems is a liquid crystal display element including the liquid crystal alignment film described above.

In addition, another aspect of the present invention that solves the above problems is a method for manufacturing a liquid crystal alignment film, which includes the steps of: applying the liquid crystal alignment agent described in any of the above on a substrate to form a coating film; A step of firing the coating film; a step of subjecting the fired film to an alignment treatment. [Inventive effect]

The liquid crystal alignment agent according to the present invention can provide a liquid crystal alignment film and a liquid crystal display element using the liquid crystal alignment film, which can ensure a high voltage retention rate even under a high temperature and high humidity over a long period of time. That is, the liquid crystal alignment film and the liquid crystal display element and the method for manufacturing the liquid crystal alignment film according to the present invention can respond to the expectations for the characteristics of the liquid crystal alignment film or the liquid crystal display element with the recent high performance. [Form of Implementing Invention]

The liquid crystal alignment agent of this embodiment contains a diamine having a structure having the following formula (1) and at least one kind of side chain structure selected from the group represented by the following formulae [S1] to [S3]. A polymer of a diamine component of an amine and a polyimide precursor obtained from a tetracarboxylic acid component and / or a polyimide of a polyimide of the polyimide precursor.

Hereinafter, a diamine having a structure of the formula (1) is sometimes referred to as a "diamine having a specific structure" or a "specific diamine". In addition, at least one diamine having a side chain structure selected from the group represented by the formulas [S1] to [S3] may be referred to as a "diamine having a specific side chain structure". The above-mentioned polymer containing a specific diamine and a diamine having a specific side chain structure of the present invention may be referred to as a "specific polymer" in some cases. Hereinafter, each constituent element will be described in detail.

<Specific diamine> Specific diamines have a structure of the following formula (1).

In the formula (1), A ¹ and A ⁵ each independently represent a single bond or an alkylene group having 1 to 5 carbon atoms. From the viewpoint of reactivity with the functional group in the sealing material to which the upper and lower substrates are bonded, a single bond or a methyl group is preferred.

In the above formula (1), A ² and A ⁴ each independently represent an alkylene group having 1 to 5 carbon atoms, and is preferably a methyl group or an ethyl group. A ³ represents an alkylene group or a cycloalkylene group having 1 to 6 carbon atoms, and from the viewpoint of reactivity with a functional group in the sealing material, methylene group or ethylene group is preferred.

In the above formula (1), B ¹ and B ² each independently represent a single bond, -O-, -NH-, -N (CH ₃ )-, -CO-, -COO-, -OCO-, -CONH -, -NHCO-, -CON (CH ₃ )-or -N (CH ₃ ) CO-. From the viewpoint of the alignment of the obtained liquid crystal alignment film, a single bond or -O- is preferred.

In the above formula (1), D ₁ represents a protecting group substituted with a hydrogen atom by heat. D ₁ is a functional group that functions as a protective group for an amine group, and its structure is not particularly limited as long as it is a protective group substituted with a hydrogen atom by heat. From the standpoint of storage stability of the liquid crystal alignment agent, D ₁ is preferably a protective group that does not detach at room temperature, more preferably a protective group that detaches with heat of 80 ° C or higher, and more preferably 100 ° C or higher, especially Protective group for detachment by heat above 120 ° C. The detachment temperature is preferably 250 ° C or lower, and more preferably 230 ° C or lower. Excessive detachment temperatures may cause polymer decomposition. Examples of such D ₁ include a tert-butoxycarbonyl (t-Boc) group and a 9-fluorenylmethoxycarbonyl group. Among these, a t-Boc group is preferred in terms of the releasability by temperature.

In the formula (1), a is 0 or 1. A ² and A ³ (when a is 1), A ³ and A ⁴ (when a is 1), or A ² and A ⁴ (when a is 0) are not bonded to each other. In other words, when a is 1, a ring cannot be formed by A ² and A ³ , A ³ and A ⁴ , and the N atom bonded to D ₁ does not form a part of the ring. Similarly, when a is 0, a ring cannot be formed by A ² and A ⁴ , and the N atom bonded to D ₁ does not constitute a part of the ring.

In the formula (1), * represents a site bonded to another base. From * point of view, the bonding position of A ¹ and / or A ⁵ of the p-benzene ring can be any of the ortho, meta, and para positions, but from the viewpoint of liquid crystal alignment of the liquid crystal alignment film, it is preferable For alignment. That is, the formula (1) is preferably the following formula (1 ') or the following formula (1 ").

In the formula (1 ′) and the formula (1 ”), A ¹ to A ⁵ , B ¹ , B ² , D ₁ , a, and * are the same as those in the formula (1).

Specific examples of such a specific diamine include diamines represented by the following formulae (1-1) to (1-18).

Specific examples of the specific diamine represented by the formula (1) include the following formulae (1-19) to (1-21).

These specific diamines can be used alone or in combination of two or more. In accordance with the characteristics required for a liquid crystal alignment film or a liquid crystal display element, one type may be used alone or two or more types may be used, or when two or more types are used, the ratio and the like may be appropriately adjusted.

The method for synthesizing a specific diamine is not particularly limited. Examples thereof include a method in which a nitro group is converted to an amine group by a reduction reaction using a dinitro compound having a structure corresponding to the structure represented by the formula (1).

The catalyst used in the above reduction reaction can be used as long as it is an activated carbon-supporting metal that can be obtained from a commercially available product. Generally, a widely used palladium-activated carbon can easily obtain good results and is therefore preferred. In order to make the reduction reaction more effective, the reaction may be performed in the coexistence of activated carbon. The solvent used for the synthesis of the specific diamine can be used without any limitation as long as it is a solvent that does not react with each raw material. The solvent may be used singly or in combination of two or more kinds. The solvent may be dried by using a suitable dehydrating agent or desiccant, or it may be used as a non-aqueous solvent.

<Two-side chain diamine> In this embodiment, the two-side chain diamine which can be contained as a diamine component is represented by the following formula [1], for example.

In the above formula [1], X represents a single bond, -O-, -C (CH ₃ ) _2- , -NH-, -CO-, -NHCO-, -COO-,-(CH ₂ ) _m -,- SO ₂ -or a divalent organic group formed by any combination thereof. Among them, X is preferably a single bond, -O-, -NH-, -O- (CH ₂ ) _m -O-. Examples of "any arbitrary combination" include -O- (CH ₂ ) _m -O-, -OC (CH ₃ ) _2- , -CO- (CH ₂ ) _m- , -NH- (CH ₂ ) _m- , -SO _2- (CH ₂ ) _m- , -CONH- (CH ₂ ) _m- , -CONH- (CH ₂ ) _m -NHCO-, -COO- (CH ₂ ) _m -OCO-, etc., But it is not limited to these. m is an integer from 1 to 8.

In the above formula [1], two Y's each independently represent a side chain structure of at least one selected from the group represented by the formulas [S1] to [S3]. The details of the side chain structure represented by the formulas [S1] to [S3] will be described later.

In the above formula [1], the position of Y from X may be a meta position or an adjacent position, but is preferably an adjacent position. That is, the above formula [1] is preferably the following formula [1 '].

In the above formula [1], the positions of the two amine groups (-NH ₂ ) may be at any position on the benzene ring, but the positions are represented by the following formulas [1] -a1 to [1] -a3 Preferably, the following formula [1] -a1 is more preferable. In the following formula, X is the same as that in the formula [1]. In addition, the following formulas [1] -a1 to [1] -a3 are those in which the positions of two amine groups are described, and the symbol of Y shown in the above formula [1] is omitted.

Therefore, when the formulas [1 '] and [1] -a1 to [1] -a3 are used, the formula [1] is selected from the following formulas [1] -a1-1 to [1] -a3-2 Any one of the structures is preferable, and a structure represented by the following formula [1] -a1-1 is more preferable. In the following formulas, X and Y are the same as those in the formula [1].

These two side chain diamines represented by the above formula [1] may be used singly or in combination of two or more kinds. In accordance with the characteristics required for a liquid crystal alignment film or a liquid crystal display element, one kind may be used alone or two or more kinds may be used, or when two or more kinds are used, the ratio and the like may be appropriately adjusted.

<Diamine having a specific side chain structure> A diamine having a specific side chain structure has at least one type of side chain structure selected from the group represented by the following formulas [S1] to [S3]. Hereinafter, the diamine having a specific side chain structure will be described in the order of formulas [S1] to [S3].

Examples of the diamine having a specific side chain structure include a diamine having a specific side chain structure represented by the following formula [S1].

In the above formula [S1], X ¹ and X ² each independently represent a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH ₃ )- , -NH-, -O-, -COO-, -OCO- or-((CH ₂ ) _a1 -A ₁ ) _m1- . Wherein the plurality of a1 each independently represents an integer of 1 to 15, a plurality of A ₁ each independently represents an oxygen atom or -COO-, m ₁ is 1 to 2.

Among them, from the viewpoint of availability of raw materials or ease of synthesis, X ¹ and X ² are each a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 15), -O-,- preferably -COO- or CH ₂ O-, more preferably a single _{bond, - (CH 2) a -} (a is an integer of 1 to 10), - O -, - CH 2 O- or -COO-.

In the formula [S1], G ¹ and G ² each independently represent a divalent cyclic group selected from a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms. Any hydrogen atom on the cyclic group may be substituted by an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, or containing 1 to 3 carbon atoms. Fluoroalkoxy or fluorine atom substitution. m and n are each independently an integer of 0 to 3, and the total of m and n is 1 to 4.

In the formula [S1], R ¹ represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. Any hydrogen forming R ¹ may be replaced by fluorine. Among them, examples of the divalent aromatic group having 6 to 12 carbon atoms include phenylene, phenylene, and naphthalene. Examples of the divalent alicyclic group having 3 to 8 carbon atoms include a cyclopropyl group and a cyclohexyl group.

Therefore, as a preferable specific example of the above formula [S1], the following formulas [S1-x1] to [S1-x7] can be listed, but it is not limited to these.

In the formulas [S1-x1] to [S1-x7], R ¹ is the same as that in the formula [S1]. X ^p represents-(CH ₂ ) _a- (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO- or -OCO-. A ₁ represents an oxygen atom or -COO- * (bonded with "*" and (CH ₂ ) _a2 ). A ₂ represents an oxygen atom or * -COO- (bonded with "*" and (CH ₂ ) _a2 ). a ₁ is an integer of 0 or 1, and a ₂ is an integer of 2-10. Cy, that is, a cyclohexane ring, the group recorded with Cy represents 1,4-cyclohexyl or 1,4-phenylene.

Examples of the diamine having a specific side chain structure include a diamine having a specific side chain structure represented by the following formula [S2].

In the above formula [S2], X ³ represents a single bond, -CONH-, -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO-, or -OCO- . Among them, from the viewpoint of liquid crystal alignment of the liquid crystal alignment agent, X ³ is preferably -CONH-, -NHCO-, -O-, -CH ₂ O-, -COO-, or -OCO-.

In the formula [S2], R ² represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. Any hydrogen that forms R ² may be replaced by fluorine. Among them, from the viewpoint of liquid crystal alignment of the liquid crystal alignment agent, R ² is preferably an alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms.

Examples of the diamine having a specific side chain structure include a diamine having a specific side chain structure represented by the following formula [S3].

In the formula [S3], X ⁴ represents -CONH-, -NHCO-, -O-, -COO-, or -OCO-. R ³ represents a structure having a steroid skeleton. The steroid skeleton here has a skeleton represented by the following formula (st) in which three six-membered rings and one five-membered ring are bonded.

Examples of the formula [S3] include the following formula [S3-x], but are not limited thereto.

In the formula [S3-x], X represents the formula [X1] or [X2]. In addition, Col represents at least one selected from the group consisting of the above formulas [Col1] to [Col4], and G represents the above formula [G1] or [G2]. * Indicates a part bonded to another base.

Examples of preferred combinations of X, Col, and G in the formula [S3-x] include the following. That is, the combination of [X1] and [Col1] and [G1], the combination of [X1] and [Col1] and [G2], the combination of [X1] and [Col2] and [G1], [X1] and [ The combination of Col2] and [G2], the combination of [X1] and [Col3] and [G2], the combination of [X1] and [Col4] and [G2], the combination of [X1] and [Col3] and [G1] , [X1] and [Col4] and [G1], [X2] and [Col1] and [G2], [X2] and [Col2] and [G2], [X2] and [Col2] And [G1], [X2] and [Col3] and [G2], [X2] and [Col4] and [G2], [X2] and [Col1] and [G1], [ X2] in combination with [Col4] and [G1].

Specific examples of the formula [S3] include a structure obtained by removing a hydroxyl group (hydroxyl group) from a steroid compound described in paragraph [0024] of Japanese Patent Application Laid-Open No. 4-281427, and a paragraph [0030] of the same publication. The structure of the steroid compound described in the acid chloride group removed, the structure of the steroid compound removed in the paragraph [0038] of the same publication, the structure of the steroid compound removed in the paragraph [0042] of the same publication, the structure of the halogen group removed, And the structures described in paragraphs [0018] to [0022] of Japanese Patent Application Laid-Open No. 8-146421.

These diamines having at least one specific side chain structure selected from the group represented by the above formulae [S1] to [S3] may be used alone or in combination of two or more. In accordance with the characteristics required for a liquid crystal alignment film or a liquid crystal display element, one kind may be used alone or two or more kinds may be used, or when two or more kinds are used, the ratio and the like may be appropriately adjusted.

A representative example of the steroid skeleton includes cholesterol (a combination of [Col1] and [G2] in the above formula [S3-x]), but a steroid skeleton not containing the cholesterol may be used. That is, the diamine having a steroid skeleton includes, for example, cholestyryl 3,5-diaminobenzoate, and the like, but it may be a diamine component that does not contain a diamine having such a cholesterol skeleton. In addition, a diamine having a specific side chain structure can also be used if the diamine and the side chain are not bonded to each other. By using such a diamine, in this embodiment, a diamine component containing no diamine having a cholesterol skeleton can be used to provide a liquid crystal alignment film or a liquid crystal display element that can ensure a high voltage retention rate over a long period of time. Liquid crystal alignment agent.

As described above, the diamine component of the present invention is a diamine containing a diamine having the structure of the formula (1) and at least one diamine having a side chain structure selected from the group represented by the formulas [S1] to [S3]. amine.

Examples of the diamine having a side chain structure represented by the formulae [S1] to [S3] include diamines each having a structure of the following formulae [1-S1]-[1-S3]. Of course, in addition to this, two side chains of the two side chain diamines also include at least one type of diamine having a side chain structure selected from the group represented by the above formulae [S1] to [S3]. The two side chain diamines are as described above.

In the formula [1-S1], X ¹ , X ² , G ¹ , G ² , R ¹ , m, and n are the same as those in the formula [S1]. In the formula [1-S2], X ³ and R ² are the same as those in the formula [S2]. In the formula [1-S3], X ⁴ and R ³ are the same as those in the formula [S3].

<Other diamine: diamine having a photoreactive side chain> The diamine component of this embodiment may contain a diamine having a photoreactive side chain as another diamine. Since the diamine component has a diamine having a photoreactive side chain, it becomes possible to introduce a photoreactive side chain into a specific polymer or a polymer other than the polymer.

Examples of the diamine having a photoreactive side chain include those represented by the following formula [VIII] or [IX], but are not limited thereto.

In the formula [VIII] and the formula [IX], the position of the two amine groups (-NH ₂ ) may be at any position on the benzene ring. For example, with respect to the bonding group of the side chain, examples include the group on the benzene ring. Position 2,3, Position 2,4, Position 2,5, Position 2,6, Position 3,4, or Position 3,5. From the viewpoint of reactivity when synthesizing polyamic acid, the position of 2,4, the position of 2,5, or the position of 3,5 is preferred. From the viewpoint of ease of synthesis of diamine, the position of 2, 4 or 3, 5 is more preferable.

In the above formula [VIII], R ⁸ represents a single bond, -CH _2- , -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N (CH ₃ )-, -CON (CH ₃ )-, or -N (CH ₃ ) CO-. In particular, R ⁸ is preferably a single bond, -O-, -COO-, -NHCO-, or -CONH-.

In the above formula [VIII], R ⁹ represents a single bond or an alkylene group having 1 to 20 carbon atoms which may be substituted with a fluorine atom. The -CH ₂ -group of the alkylene group herein may be optionally substituted by -CF ₂ -or -CH = CH-. When any of the following groups are not adjacent to each other, they may also be substituted as such groups; -O -, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, a divalent carbocyclic or heterocyclic ring. The divalent carbocyclic ring or heterocyclic ring includes, specifically, the following formula (1a), but is not limited thereto.

In the above formula [VIII], R ⁹ can be formed by a general organic synthesis method. However, from the viewpoint of ease of synthesis, a single bond or an alkylene group having 1 to 12 carbon atoms is preferred.

In the formula [VIII], R ¹⁰ represents a photoreactive group selected from the group consisting of the following formula (1b). Among them, R ¹⁰ is preferably a methacrylfluorenyl group, acrylfluorenyl group, or vinyl group from the viewpoint of photoreactivity.

In the formula [IX], Y ₁ represents -CH _2- , -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, or -CO-. Y ₂ represents an alkylene group having 1 to 30 carbon atoms, a divalent carbocyclic ring or a heterocyclic ring. One or more hydrogen atoms in the alkylene group, the divalent carbocyclic ring or the heterocyclic ring may be substituted by a fluorine atom or an organic group. When the following Y ₂ groups are not adjacent to each other, -CH ₂ -may be substituted as such a group; -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-,- NHCONH-, -CO-.

In the formula [IX], Y ₃ represents -CH _2- , -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, -CO-, or a single bond. Y ₄ represents cassia hydrazone. Y ₅ represents a single bond, an alkylene group having 1 to 30 carbon atoms, a divalent carbocyclic ring or a heterocyclic ring. One or more hydrogen atoms in the alkylene group, the divalent carbocyclic ring or the heterocyclic ring may be substituted by a fluorine atom or an organic group. When the bases below Y ₅ are not adjacent to each other, -CH ₂ -may be substituted as such a base; -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH-,- NHCONH-, -CO-. Y ₆ represents a photopolymerizable group such as acrylfluorenyl or methacrylfluorenyl.

Specific examples of the diamine having such a photoreactive side chain represented by the formula [VIII] or [IX] include the following formula (1c), but the invention is not limited thereto.

In the formula (1c), X ⁹ and X ¹⁰ each independently represent a single bond, -O-, -COO-, -NHCO-, or -NH- bonding group. Y represents an alkylene group having 1 to 20 carbon atoms which may be substituted by a fluorine atom.

Examples of the diamine having a photoreactive side chain include a diamine of the following formula [VII]. The diamine of the formula [VII] has a site having a radical generating structure in a side chain. In the free radical generating structure, it is decomposed by ultraviolet irradiation and free radicals are generated.

In the above formula [VII], Ar represents at least one aromatic hydrocarbon group selected from the group consisting of phenylene, naphthyl and phenylene. The hydrogen atoms of their rings may be substituted with halogen atoms. . Ar based on a carbonyl group is related to the absorption wavelength of ultraviolet light. Therefore, when a long wavelength is used, a structure having a longer conjugate length of a naphthyl group or a biphenyl group is preferred. On the other hand, when Ar has a structure such as a naphthyl group or a biphenylene group, solubility may be deteriorated, and in this case, the difficulty of synthesis becomes high. As long as the wavelength of the ultraviolet rays is in the range of 250 nm to 380 nm, sufficient characteristics can be obtained even with a phenyl group, so Ar is most preferably a phenyl group.

In the Ar, an aromatic hydrocarbon group may be substituted. Examples of the substituent herein are preferably an organic group such as an alkyl group, a hydroxyl group, an alkoxy group, an amine group, or the like having an electron donor.

In the formula [VII], R ₁ and R ₂ each independently represent an alkyl group, an alkoxy group, a benzyl group, or a phenethyl group having 1 to 10 carbon atoms. In the case of an alkyl group or an alkoxy group, a ring may be formed by R ₁ and R ₂ .

In the above formula [VII], T ₁ and T ₂ each independently represent a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N (CH ₃ )-, -CON (CH ₃ )-, or -N (CH ₃ ) CO- bonding group.

In formula [VII], S represents a single bond, an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms. The alkylene group -CH ₂ -or -CF ₂ -may be optionally substituted by -CH = CH-. When any of the groups listed below are not adjacent to each other, they may be substituted as such groups; -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, a divalent carbocyclic ring, a divalent heterocyclic ring.

In formula [VII], Q represents a structure selected from the following formula (1d).

In the formula (1d), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ₃ represents -CH _2- , -NR-, -O-, or -S-.

In the above formula [VII], Q is preferably an electron-donating organic group, and is preferably an alkyl group, a hydroxyl group, an alkoxy group, an amine group, or the like, which is also exemplified in the example of Ar. When Q is an amine derivative, during polymerization of the polyamidoprecursor of the polyamidoimide precursor, undesired situations such as the formation of a carboxylic acid group and an amine group may occur, so it is more preferably a hydroxyl group or Alkoxy.

In addition, in the formula [VII], the positions of the two amine groups (-NH ₂ ) may be any of o-phenylenediamine, m-phenylenediamine, or p-phenylenediamine, but they are related to the acid From the viewpoint of the reactivity of dianhydride, m-phenylenediamine or p-phenylenediamine is preferred.

Therefore, preferable specific examples of the above formula [VII] include the following formulas from the viewpoints of ease of synthesis, height of general versatility, and characteristics. In the following formula, n is an integer of 2-8.

These diamines having a photoreactive side chain represented by the above formula [VII], [VIII] or [IX] may be used alone or in combination of two or more. When used as a liquid crystal alignment film, the liquid crystal alignment, pretilt angle, voltage holding characteristics, accumulated charge, and other characteristics, as well as the liquid crystal response speed when used as a liquid crystal display element, can be used alone or in combination of two or more. When using more than one kind, the ratio and the like may be adjusted appropriately.

In this embodiment, when the diamine component contains a photoreactive side chain diamine, the photoreactive side chain diamine is preferably 10 to 70 mole% of the total diamine component, and more preferably 20 to 60 mole. Ear%, and more preferably 30-50 mole%.

<Other diamines: Diamines other than the above> Other diamines that can be contained in the diamine component for obtaining a specific polymer are not limited to diamines having the above-mentioned photoreactive side chains and the like. Examples of the diamine other than the diamine having the photoreactive side chain include those represented by the following formula [2].

In the above formula [2], A ₁ and A ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms or an alkynyl group having 2 to 5 carbon atoms. Among these, from the viewpoint of the reactivity of the monomers, A ₁ and A ₂ are preferably a hydrogen atom or a methyl group. When the structure of Y ₁ is listed, the following formulae (Y-1) to (Y-148) and (Y-155) to (Y-174) can be cited.

In the above formula, in particular, if the range of n is not described, n is an integer of 1 to 6. In the above formula, Me represents a methyl group.

In the above formula, Boc represents a third butoxycarbonyl group.

The other diamines including the diamine having the photoreactive side chain described above may be used singly or in combination of two or more kinds. When the diamine component contains other diamines, the specific diamine may be appropriately set within a range that does not impair the effect of the present invention when compared to other diamines in the specific polymer.

<Tetracarboxylic acid component> 之 Examples of the tetracarboxylic acid component for obtaining a specific polymer include tetracarboxylic acid, tetracarboxylic dianhydride, tetracarboxylic dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid dioxane. Ester dihalides are collectively referred to herein as tetracarboxylic acid components.

As the tetracarboxylic acid component, a tetracarboxylic acid dianhydride or a derivative thereof, a tetracarboxylic acid, a tetracarboxylic acid dihalide, a tetracarboxylic acid dialkyl ester, or a tetracarboxylic acid dialkyl dihalide (these can be used) Collectively referred to as the first tetracarboxylic acid component).

Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples of these include the following groups [1] to [5].

[1] aliphatic tetracarboxylic dianhydride, such as 1,2,3,4-butanetetracarboxylic dianhydride, etc .;

[2] An alicyclic tetracarboxylic dianhydride, such as an acid dianhydride of the following formulae (X1-1) to (X1-13);

In the above formulae (X1-1) to (X1-4), R ₃ to R ₂₃ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and a carbon number 2 An alkynyl group of ~ 6, a monovalent organic group of 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group. R _M represents a hydrogen atom or a methyl group. In the formula (X1-13), Xa represents a tetravalent organic group represented by the following formulae (Xa-1) to (Xa-7).

[3] 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 3,5,6- Tricarboxy-2-carboxymethyl norbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.02,6] undecane-3,5,8,10 -Tetraketone, etc .;

[4] Aromatic tetracarboxylic dianhydride, for example, pyromellitic anhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, 3,3', 4,4'- Diphenylphosphonium tetracarboxylic dianhydride, acid dianhydride represented by the following formulae (Xb-1) to (Xb-10), etc., and

[5] An acid dianhydride represented by the formulae (X1-44) to (X1-52), and a tetracarboxylic dianhydride described in Japanese Patent Application Laid-Open No. 2010-97188.

The tetracarboxylic acid components described above can be used alone or in combination of two or more. Depending on the characteristics required for a liquid crystal alignment film or a liquid crystal display element, one type may be used alone, or two or more types may be used, or the two or more types may be used, and the ratio and the like may be appropriately adjusted.

<The manufacturing method of a specific polymer> (2) A specific polymer is obtained by the method of making the diamine component and the tetracarboxylic-acid component react in this embodiment demonstrated above. This method may include, for example, a diamine component composed of one or more types of diamines and at least one tetracarboxylic acid selected from the group consisting of tetracarboxylic dianhydrides and derivatives of tetracarboxylic acids. A method in which an acid component is reacted to obtain polyamic acid. Specifically, a method of polycondensing a diamine of the first or second order with a tetracarboxylic dianhydride to obtain a polyamic acid is used.

In order to obtain a polyalkylamino acid alkyl ester, a method of polycondensing a tetracarboxylic acid having a dialkyl esterified carboxylic acid group and a diamine of a first or second order can be used. A method of polycondensing a carboxylic acid dihalide with a diamine of class 1 or 2, or a method of converting a carboxyl group of a polyamic acid into an ester. In order to obtain a polyimide, the method of making the said polyamidic acid or a polyalkylamic acid alkylate ring-close as a polyimide can be used.

The reaction of the diamine component and the tetracarboxylic acid component is usually performed in a solvent. The solvent used at this time is not particularly limited as long as the produced polyimide precursor is dissolved. Examples of the solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, and N, N-dimethylformamide. Ethamidine, dimethylsulfinium, or 1,3-dimethyl-imidazolinone. When the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the following formula [ D-1] ~ [D-3], etc.

In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms. In the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms. In the formula [D-3], D ³ represents an alkyl group having 1 to 4 carbon atoms.

These solvents can be used alone or in combination of two or more. Even if the solvent does not dissolve the polyfluorene imide precursor, as long as it is within a range in which the generated polyfluorene imide precursor does not precipitate, it can be used in combination with the solvent. In addition, the water in the solvent will hinder the polymerization reaction and cause hydrolysis of the produced polyimide precursor. Therefore, it is preferable to use a solvent that is dehydrated and dried.

When the diamine component and the tetracarboxylic acid component are reacted in a solvent, the solution in which the diamine component is dispersed or dissolved in the solvent is stirred, and the tetracarboxylic acid component is directly or dispersedly dispersed or dissolved in the solvent and added. On the contrary, a method of adding a diamine component to a solution in which a tetracarboxylic acid component is dispersed or dissolved in a solvent, a method of adding a diamine component and a tetracarboxylic acid component alternately, etc., any of these may be used method. When a diamine component or a tetracarboxylic acid component is reacted by using a plurality of types, they may be reacted in a pre-mixed state or individually individually. In addition, the low-molecular-weight bodies of the individual reactions may be mixed and reacted. polymer.

The temperature at which the diamine component and the tetracarboxylic acid component are polycondensed may be any temperature of -20 to 150 ° C, but is preferably in the range of -5 to 100 ° C. The reaction can be carried out at any concentration, but when the concentration is too low, it becomes difficult to obtain a polymer with a high molecular weight. When the concentration is too high, the viscosity of the reaction solution becomes too high, and uniform stirring becomes difficult. Therefore, it is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass. The reaction can be performed at a high concentration in the initial stage, and a solvent is added thereafter.

The polymerization reaction of the polyfluorene imide precursor is a ratio of the total mole number of the diamine component to the total mole number of the tetracarboxylic acid component, and preferably 0.8 to 1.2. As with the usual polycondensation reaction, the closer this mole ratio is to 1.0, the larger the molecular weight of the resulting polyfluorene imide precursor.

Polyimide is a polyimide obtained by ring closure of the aforementioned polyimide precursor. In this polyimide, the ring-closing rate of the amido acid group (also known as the amidation rate) does not necessarily need to be 100. % Can be adjusted arbitrarily according to the purpose or purpose. The method for performing polyimidization of the polyimide precursor may include heat-imidization by heating the polyimide precursor in a solution state, or adding a catalyst to the solution of the polyimide precursor. Catalyst 醯 imidization.

The temperature at which the polyfluorene imine precursor is thermally fluorinated in the solution is 100 to 400 ° C, preferably 120 to 250 ° C, and the water generated by the fluorene imidization reaction is removed outside the system. Better. Polyimide precursor catalyst 醯 imidization is added to the solution of polyimide precursor, alkaline catalyst and acid anhydride are added, by -20 ℃ ~ 250 ℃, preferably 0 ℃ ~ 180 Stirring was performed at ℃.

The amount of the alkaline catalyst is 0.5 to 30 mol times of the amino acid group, preferably 2 to 20 mol times, and the amount of the acid anhydride is 1 to 50 mol times of the amino acid group, preferably 3 to 30 mol times. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferred because it has a moderate basicity required for the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. In particular, when acetic anhydride is used, purification after the completion of the reaction becomes easy, so it is preferable. The rate of imidization caused by catalyst imidization can be controlled by adjusting the amount of catalyst, the reaction temperature, and the reaction time.

When recovering the produced polyimide precursor or polyimide from the polyimide precursor or the polyimide reaction solution, the reaction solution may be put into a solvent to precipitate. Examples of the solvent used for the precipitation include methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. After the solvent is charged, the precipitated polymer can be recovered by filtration and then dried under normal pressure or reduced pressure, or at normal temperature or by heating. In addition, when the polymer recovered by precipitation is redissolved in a solvent, and the operation of reprecipitation recovery is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the solvent in this case include alcohols, ketones, and hydrocarbons. When three or more solvents selected from these are used, the purification efficiency is further improved, so it is preferable.

Examples of a more specific method for producing the polyalkylamic acid alkyl ester of the present invention are shown in the following (1) to (3), respectively.

(1) Production method by esterification reaction of polyamic acid This method is, for example, producing polyamino acid from a diamine component and a tetracarboxylic acid component, and performing a chemical reaction on the carboxyl group (COOH group), that is, esterification A method for reacting to produce a polyalkylammonium ester. The esterification reaction is a reaction of polyamine and an esterifying agent in the presence of a solvent at a temperature of -20 to 150 ° C (preferably 0 to 50 ° C) for 30 minutes to 24 hours (preferably 1 to 4 hours). )Methods.

The esterification agent is preferably one which can be easily removed after the esterification reaction, and examples thereof include N, N-dimethylformamide dimethyl acetal and N, N-dimethylformamide diethyl Acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide dineopentylbutyl acetal, N, N-dimethylformamide di- t-butylacetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p-tolyltriazine Alkenes, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylchloromorpholine salts and the like. The amount of the esterifying agent used is 1 mole, preferably 2 to 6 mole equivalents, relative to the repeating unit of the polyamidic acid. Among them, 2 to 4 mole equivalents are preferred.

The solvent used for the said esterification reaction is a solvent used for the reaction of the said diamine component and the tetracarboxylic-acid component from a viewpoint of the solubility of a polyamic acid in a solvent. Among them, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. These solvents can be used singly or in combination of two or more kinds. From the viewpoint that the concentration of polyamic acid in the solvent in the above-mentioned esterification reaction is unlikely to cause precipitation of polyamic acid, it is preferably 1 to 30% by mass. Among them, 5 to 20% by mass is preferred.

(2) Method for producing by reacting a diamine component with a tetracarboxylic acid diester dichloride This method is, for example, a method in which a diamine component and a tetracarboxylic acid diester dichloride are present in the presence of a base and a solvent at- A method of reacting at 20 to 150 ° C (preferably 0 to 50 ° C) for 30 minutes to 24 hours (preferably 1 to 4 hours). As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used. Among them, since the reaction proceeds mildly, pyridine is preferred. The amount of the base used is preferably an amount that can be easily removed after the reaction. It is preferably 2 to 4 times the mole, more preferably 2 to 3 times the mole relative to the tetracarboxylic acid diester dichloride.

From the viewpoint of the solubility of the obtained polymer, that is, the alkyl polyamidate in a solvent, examples of the solvent include solvents used for the reaction between the diamine component and the tetracarboxylic acid component. Among them, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. These solvents can be used alone or in combination of two or more.

The concentration of the polyalkylamic acid alkyl ester in the solvent during the reaction is preferably from 1 to 30% by mass from the viewpoint that the precipitation of the polyalkylamino alkyl ester is unlikely to occur. Among them, 5 to 20% by mass is preferred. In addition, in order to prevent the hydrolysis of the tetracarboxylic acid diester dichloride, it is preferable that the solvent used in the production of the polyalkylamino alkyl ester is dehydrated as much as possible. In addition, the reaction is performed in a nitrogen atmosphere, and it is preferable to prevent external air from being mixed.

(3) Method for producing by reacting a diamine component with a tetracarboxylic acid diester This method is, for example, making a diamine component and a tetracarboxylic acid diester in the presence of a condensing agent, a base, and a solvent at 0 to 150 ° C. A method of polycondensation reaction (preferably 0 to 100 ° C) for 30 minutes to 24 hours (preferably 3 to 15 hours).

As the condensing agent, triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N'- Carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholine, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethylurea Onium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethylmethylurea hexafluorophosphate, (2,3-dihydro-2- Thioxy-3-benzoxazolyl) diphenylphosphonate and the like. The amount of the condensing agent is preferably 2 to 3 times the mole compared to the tetracarboxylic acid diester, especially 2 to 2.5 times the mole.

As the base, tertiary amines such as pyridine and triethylamine can be used. The amount of the base used is preferably an amount that can be easily removed after the polycondensation reaction. It is more preferably 2 to 4 times the mole and more preferably 2 to 3 times the mole of the diamine component. From the viewpoint of the solubility of the obtained polymer, that is, the alkyl polyamidate to a solvent, the solvent used in the polycondensation reaction includes the solvent used in the reaction of the diamine component and the tetracarboxylic acid component. Among them, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. These solvents can be used singly or in combination of two or more.

In the polycondensation reaction, the reaction is efficiently performed by adding a Lewis acid as an additive. The Lewis acid is preferably a lithium halide such as lithium chloride or lithium bromide. The amount of the Lewis acid used is preferably 0.1 to 10 times the mole relative to the diamine component. Among them, it is preferably 2.0 to 3.0 times mole.

When recovering the polyalkylamine from the solution of the polyalkylamine obtained by the methods (1) to (3) above, the reaction solution may be added to a solvent to precipitate. Examples of the solvent used for the precipitation include water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, and toluene. A solvent is added to precipitate the polymer, and the purpose of removing the additives and catalysts used above is preferably to perform a plurality of washing operations with the solvent. After being washed, recovered by filtration, the polymer may be dried under normal pressure or reduced pressure, or at normal temperature or by heating. In addition, the polymer recovered by precipitation is redissolved in a solvent, and the operation of reprecipitation recovery is repeated 2 to 10 times, which can reduce impurities in the polymer. The polyalkylene alkanoate is preferably produced by the above-mentioned (2) or (3).

<Liquid crystal alignment agent> The liquid crystal alignment agent of the present invention contains the specific polymer described above, but may also contain two or more specific polymers having different structures. In addition to the specific polymer, it may contain other polymers, that is, polymers that do not have a divalent group represented by formula (1) (polymers containing no specific diamine represented by formula (1)). Examples of the polymer include polyamic acid, polyimide, polyamidate, polyester, polyamine, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, and polyphenylene Ethylene or its derivatives, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates, and the like. When the liquid crystal alignment agent of the present invention contains other polymers, the ratio of the specific polymer to the total polymer component is preferably 5% by mass or more, and examples thereof include 5 to 95% by mass.

The liquid crystal alignment agent generally adopts the form of a coating liquid from the viewpoint of forming a uniform thin film. The liquid crystal alignment agent of the present invention is also preferably a coating solution containing the polymer component and an organic solvent that dissolves the polymer component. At this time, the concentration of the polymer in the liquid crystal alignment agent can be appropriately changed by setting the thickness of the coating film to be formed. From a viewpoint of forming a uniform and defect-free coating film, 1 mass% or more is preferable, and from a viewpoint of storage stability of a solution, 10 mass% or less is preferable. The concentration of the particularly good polymer is 2 to 8% by mass.

The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as it dissolves the polymer component uniformly. Specific examples include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and dimethylsulfinium , Γ-butyrolactone, 1,3-dimethyl-imidazolinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, and the like. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone is preferably used.

In addition, as the organic solvent contained in the liquid crystal alignment agent of the present invention, in addition to the solvents described above, a solvent that improves the coatability when applying the liquid crystal alignment agent or the surface smoothness of the coating film may be used. Specific examples of the organic solvent are listed below, but are not limited thereto.

Examples include ethanol, isopropanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1 -Butanol, isoamyl alcohol, tert-pentanol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol Alcohol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol , 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6-dimethyl-4-heptanol, 1,2-ethylene glycol, 1,2- Propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2- Methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diisopropyl ether, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl Ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2 -Pentanone, diethylene glycol methyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dione Methyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, carbonic acid Propylene ester, Ethylene carbonate, 2- (methoxymethoxy) ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexaneoxy Based) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, diethylene glycol monoethyl ether, diethylene glycol Ethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethyl acetate Glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2 -Ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, Methyl acetate, ethyl acetate, n-butyl acetate , Propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl ethyl 3-ethoxypropionate, 3- Ethyl methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate Esters, n-propyl lactate, n-butyl lactate, isoamyl lactate, solvents represented by the above formulas [D-1] to [D-3], and the like.

Among them, 1-hexanol, cyclohexanol, 1,2-ethylene glycol, 1,2-propylene glycol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, and 4-hydroxy-4-methyl are used as the organic solvent. 2-pentanone, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether is preferred. The type and content of this solvent are appropriately selected in accordance with the coating device, coating conditions, and coating environment of the liquid crystal alignment agent.

The liquid crystal alignment agent of the present invention may further contain components other than the polymer component and the organic solvent. Examples of such additional components include adhesion promoters for improving the adhesion between the liquid crystal alignment film and the substrate, adhesion adhesives for the adhesion between the liquid crystal alignment film and the sealing material, crosslinking agents for increasing the strength of the liquid crystal alignment film, and adjustment of the liquid crystal. A dielectric body or a conductive substance for the dielectric constant or electrical resistance of the alignment film. Specific examples of these additional components include weak solvents or crosslinkable compounds disclosed in paragraphs [0104] to 60 of paragraphs [0116] on page 53 of International Publication No. 2015/060357.

The liquid crystal alignment agent of the present invention may contain, in addition to the above, a polymer other than the specific polymer described in the present invention, a dielectric body for the purpose of changing the electrical characteristics such as the dielectric constant or conductivity of the liquid crystal alignment film, and improving A silane coupling agent for the purpose of adhesion between the liquid crystal alignment film and the substrate, a crosslinkable compound for the purpose of improving the hardness or density of the film when used as a liquid crystal alignment film, and a polymerized film efficiently during firing. An imidation accelerator for the purpose of imidization caused by the heating of an imine precursor.

Examples of the compound for improving the adhesion between the liquid crystal alignment film and the substrate include a compound containing a functional silane or a compound containing an epoxy group, and examples include a 3-aminopropyltrimethoxysilane and a 3-aminopropyltriamine. Ethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane , 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2 -Aminoamino) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl -3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilane triethylene triamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-tris Azadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxy Alkyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N -Phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane , N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol di Glycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dioxane Bromo neopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ', N',-tetraglycidyl-m- Xylene diamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane or N, N, N ', N',-tetraglycidyl-4,4'-di Amino diphenylmethane and the like.

In addition, the liquid crystal alignment agent of the present invention can add the following additives in order to improve the mechanical strength of the liquid crystal alignment film.

The additive is preferably 0.1 to 30 parts by mass based on 100 parts by mass of the polymer component contained in the liquid crystal alignment agent. When the amount is less than 0.1 parts by mass, the effect cannot be expected, and when it exceeds 30 parts by mass, the alignment of the liquid crystal is reduced, so it is more preferably 0.5 to 20 parts by mass.

<Liquid crystal alignment film> The liquid crystal alignment film of the present invention is obtained from the above-mentioned liquid crystal alignment agent. By using the liquid crystal alignment agent of the present invention, it is possible to provide a VA method, particularly a PSA mode, which is particularly suitable for responding to liquid crystal molecules that are vertically aligned to a substrate by an electric field. Even under high temperature and high humidity, it can ensure high The voltage holding ratio of a liquid crystal alignment film or a liquid crystal display element. As an example of a method for obtaining a liquid crystal alignment film, a cured film obtained by applying the liquid crystal alignment agent of the present invention to a substrate and drying and firing as required may be directly used as a liquid crystal alignment film. In addition, the hardened film is rubbed, or polarized light or light of a specific wavelength is irradiated, or an ion beam or the like is treated, or as an alignment film for PSA, UV is irradiated in a state where a voltage is applied to a liquid crystal display element after liquid crystal filling Yes. It is especially useful as an alignment film for PSA.

The substrate to which the liquid crystal alignment agent is applied is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as a glass substrate, a silicon nitride substrate, an acrylic substrate, or a polycarbonate substrate can be used. In this case, when a substrate on which an ITO electrode for driving liquid crystal is formed is used, it is preferable from the viewpoint of simplification of steps. Moreover, in a reflective liquid crystal display element, if it is a substrate with only one side, an opaque object such as a silicon wafer may be used. In this case, the electrode may also use a material that reflects light.

The coating method of the liquid crystal alignment agent is not particularly limited, but industrially, it is generally screen printing, lithography, letterpress printing, inkjet method, and the like. Other coating methods include a dipping method, a roll coating method, a slit coating method, a spin coater method, and a spray method, and these methods can be used depending on the purpose. After the liquid crystal alignment agent is coated on the substrate, the solvent is evaporated and fired by heating means such as a hot plate, a thermal cycle oven, or an IR (infrared) oven. For the drying and firing steps after applying the liquid crystal alignment agent, any temperature and time can be selected. The drying step is not necessarily required, but when the time from coating to firing of each substrate is not fixed, or when firing is not performed immediately after coating, it is better to perform the drying step. This drying is only required to remove the solvent to such an extent that the shape of the coating film is not deformed by the transportation of the substrate or the like, and the drying means is not particularly limited. Examples thereof include a method of drying on a hot plate at a temperature of 40 ° C. to 150 ° C., preferably 60 ° C. to 100 ° C., for 0.5 minutes to 30 minutes, preferably 1 minute to 5 minutes.

The firing temperature of the coating film formed by applying the liquid crystal alignment agent is not limited, and is, for example, 100 to 350 ° C, preferably 120 to 300 ° C, and more preferably 150 ° C to 250 ° C. The firing time is 5 minutes to 240 minutes, preferably 10 minutes to 90 minutes, and more preferably 20 minutes to 90 minutes. Heating can be performed by a generally known method, such as a hot plate, a hot-air circulation furnace, and an infrared furnace.

In addition, if the thickness of the liquid crystal alignment film after firing is too thin, the reliability of the liquid crystal display element may be reduced, so it is preferably 5 to 300 nm, and more preferably 10 to 200 nm. The liquid crystal alignment film of the present invention can be used as a liquid crystal alignment film of a liquid crystal display element of a VA method, particularly a PSA mode.

<Liquid crystal display element and manufacturing method thereof> 之 The liquid crystal display element of the present invention is obtained by obtaining a substrate with a liquid crystal alignment film obtained from the liquid crystal alignment agent, and then manufacturing a liquid crystal cell by a known method, and using the liquid crystal cell as an element. A specific example of a liquid crystal display element that can be produced is a liquid crystal display element of a vertical alignment method, which is provided with a liquid crystal cell having two substrates disposed opposite to each other, a liquid crystal layer provided between the substrates, and a substrate and The liquid crystal alignment film formed between the liquid crystal layers and formed by the liquid crystal alignment agent of the present invention. Specifically, the liquid crystal alignment agent of the present invention is coated on two substrates and fired to form a liquid crystal alignment film. The two substrates are arranged in such a manner that the liquid crystal alignment films face each other, and the two substrates are arranged on the two substrates. A liquid crystal layer made of liquid crystal is sandwiched between substrates, that is, a liquid crystal layer is provided by contacting the liquid crystal alignment film, and the liquid crystal alignment film and the liquid crystal layer are applied with a voltage and irradiated with ultraviolet rays to produce the liquid crystal layer.

More specifically, a transparent glass substrate is prepared, a common electrode is provided on one of the substrates, and a segment electrode is provided on the other substrate. These electrodes can be ITO electrodes, for example, and patterned so that a desired image can be displayed. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a film made of SiO ₂ -TiO ₂ formed by a sol-gel method. Next, a liquid crystal alignment film is formed on each substrate under the conditions described above.

Next, a UV-curable sealing material is placed in a specific place on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is placed in a specific number of places on the liquid crystal alignment film surface. Then, the liquid crystal alignment film is opposed to each other, and another substrate is bonded and crimped. The liquid crystal is pushed in front of the liquid crystal alignment film, and the substrate is irradiated with ultraviolet rays, and the sealing material is hardened to obtain a liquid crystal cell.

In addition, after a liquid crystal alignment film is formed on a substrate, when a sealing material is arranged at a specific place on one of the substrates, an opening portion that can be filled with liquid crystal from the outside is first provided, and the substrate is bonded. Then, the liquid crystal material is passed through an opening portion provided in the sealing material, and then injected into the liquid crystal cell, and then the opening portion is closed with an adhesive to obtain a liquid crystal cell. The liquid crystal material may be injected by a vacuum injection method or a method using a capillary phenomenon in the atmosphere.

Regardless of the above methods, in order to ensure that the liquid crystal material is filled in the liquid crystal cell, columnar protrusions are provided on one of the substrates, or a gap is spread on the other substrate, or a gap is mixed in the sealing material. It is better to use a combination of these and other means.

The liquid crystal material is not particularly limited, but a liquid crystal material used in the VA method, particularly a liquid crystal material used in the PSA mode can be appropriately selected and used.

Next, set the polarizing plate. Specifically, it is preferable to stick a pair of polarizing plates on the opposite sides of the two substrates from the liquid crystal layer.

The liquid crystal alignment film and the liquid crystal display element of the present invention are not limited to the above-mentioned configuration or manufacturing method, as long as the liquid crystal alignment agent of the present invention is used, and may be produced by other known methods. The steps until a liquid crystal display element is obtained from the liquid crystal alignment agent are disclosed in, for example, paragraph [0074] to page 19 of paragraph [0082] in Japanese Patent Application Laid-Open No. 2015-135393.

In the case of a polymer having photoreactive side chains, the polymerizable compounds are polymerized and the photoreactive side chains or the photoreactive side chains of the polymer are reacted with the polymerizable compound, thereby being more efficient. The orientation of the liquid crystal is fixed to form a liquid crystal display element with excellent response speed.

[Example]

Examples are given below to explain the present invention in more detail, but the present invention is not limited to these. The compounds used are as follows.

(Diamine component) 化合物 Compound DA-1 represented by the following formulas [DA-1] to [DA-10]: Compound represented by formula [DA-1] (diamine having a specific side chain structure) DA-2: Formula Compound represented by [DA-2] (two side chain diamines having a specific side chain structure) DA-3: Compound (specific diamine) represented by formula [DA-3] DA-4: Represented by formula [DA-4] Compounds (other diamines) DA-5: compounds represented by formula [DA-5] (other diamines) DA-6: compounds represented by formula [DA-6] (other diamines) DA-7: Compound represented by formula [DA-7] (other diamines) DA-8: compound represented by formula [DA-8] (other diamines) DA-9: compound represented by formula [DA-9] (others Diamine) DA-10: Compound represented by the formula [DA-10] (diamine having a specific side chain structure)

(Tetracarboxylic acid component) 化合物 Compound D1 represented by the following formulas [D1] to [D4]: 1,2,3,4-cyclobutane tetracarboxylic dianhydride D2: bicyclic [3,3,0] octane- 2,4,6,8-tetracarboxylic dianhydride D3: 2,3,5-tricarboxycyclopentylacetic dianhydride D4: 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride

(Solvent) NMP: N-methyl-2-pyrrolidone BCS: ethylene glycol monobutyl ether

<Molecular weight measurement of polyimide> The molecular weight of polyimide in the synthesis example is a room temperature gel permeation chromatography (GPC) device (SSC-7200) manufactured by SENSHU Scientific Co., and a column manufactured by Shodex Corporation. (KD-803, KD-805) and measured as follows. Column temperature: 50 ° C Eluent: N, N'-dimethylformamide (the additive is lithium bromide-hydrate (LiBr ･ H ₂ O) is 30mmol / L, anhydrous crystal of phosphoric acid (o-phosphoric acid) is 30 mmol / L, tetrahydrofuran (THF) is 10ml / L) Flow rate: 1.0ml / minute Calibration line preparation Standard sample: TSK standard polyethylene oxide (molecular weight about 9,000,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, And, polyethylene glycol (molecular weight about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories.

<Measurement of fluorene imidization ratio> The fluorene imidization ratio of polyfluorene imine in the synthesis example was measured as follows. 20 mg of polyfluorene imine powder was placed in an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Science), and 0.53 ml of deuterated dimethylsulfine (DMSO-d ₆ , 0.05% TMS mixed product) was added. completely dissolved.

This solution was used to measure a proton NMR at 500 MHz using an NMR measuring device (JNW-ECA500) manufactured by Japan Electronics Datum Corporation. The hydrazone imidization rate is determined by taking protons from structures that have not changed before and after hydrazone as the reference protons. The integrated value of this proton is used, and the amines from 9.5 ~ 10.0ppm The integral value of the NH-based proton peak is obtained by the following calculation formula.醯 Imination ratio (%) = (1-α ･ x / y) × 100

<Synthesis of polyimide-based polymer> <Synthesis Example 1> D2 (3.50 g) of tetracarboxylic dianhydride, DA-1 (3.20 g) of diamine component, and DA-3 (6.69 g) were dissolved in a solvent. NMP (N1 of Table 1) (53.57g) was mixed and reacted at 60 ° C for 3 hours, then D1 (2.73g) and NMP (N2 of Table 1) (10.94g) were added and reacted at 40 ° C for 6 For hours, a polyamic acid solution was obtained.

NMP (41.54 g) was added to this polyamic acid solution (20.0 g), diluted to 6.5% by mass, and then acetic anhydride (3.55 g) and pyridine (1.10 g) were added as the imidization catalyst. The reaction was allowed to proceed at 3 ° C (the reaction temperature in Table 2) for 3 hours. This reaction solution was poured into methanol (231.64 g), and the obtained precipitate was obtained by filtration. This precipitate was washed with methanol and dried under reduced pressure at 60 ° C to obtain a polyfluorene imine powder (A) of Synthesis Example 1. The polyimide has a fluorinated imidization rate of 68%, a number average molecular weight of 12,900, and a weight average molecular weight of 44,100.

<Synthesis Examples 2 to 7> According to the method of Synthesis Example 1, the materials or ratios were changed as shown in Tables 1 and 2, and polyimide powders (B) to (G) of Synthesis Examples 2 to 7 were obtained.

<Synthesis Example 8> D2 (3.50 g) of tetracarboxylic dianhydride, DA-2 (2.12 g), and DA-3 (2.87 g) of diamine components were dissolved in a solvent NMP (N1 of Table 1) (47.29 g) After mixing for 3 hours at 60 ° C, D1 (2.60g) and NMP (N2 in Table 1) (3.87g) were added, and the reaction was allowed to proceed at room temperature for 1 hour. Then D4 (2.71g) and NMP were added. (N3 in Table 1) (10.83 g), and reacted at room temperature for 6 hours to obtain a polyamic acid solution. According to the method of Synthesis Example 1, the materials and ratios of this polyfluorinated acid solution were changed as shown in Table 2 to obtain polyimide powder (H) of Synthesis Example 8.

<Synthesis Example 9> D3 (6.15 g) of tetracarboxylic dianhydride, DA-2 (4.24 g) of diamine component, DA-3 (1.91 g), DA-4 (0.93 g), DA-8 ( 2.78 g) was mixed in a solvent NMP (N1 of Table 1) (64.05 g) and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. According to the method of Synthesis Example 1, the materials and ratios of this polyfluorenic acid solution were changed as shown in Table 2 to obtain Polyimide powder (I) of Synthesis Example 9.

<Comparative Synthesis Example 1> D2 (3.50 g) of tetracarboxylic dianhydride, DA-1 (3.20 g) and DA-4 (6.47 g) of diamine components were added to NMP (N1 of Table 1) (52.70 g) After mixing at room temperature and reacting at 60 ° C for 3 hours, D1 (2.73 g) and NMP (N2 in Table 1) (10.92 g) were added, and the reaction was performed at 40 ° C for 6 hours to obtain a polyamic acid solution.

NMP (41.54g) was added to this polyamidic acid solution (20.0g), diluted to 6.5% by mass, and then acetic anhydride (3.60g) and pyridine (1.11g) were added as the imidization catalyst. The reaction was allowed to proceed at 3 ° C for 3 hours. This reaction solution was poured into methanol (231.87 g), and the obtained precipitate was obtained by filtration. This precipitate was washed with methanol and dried under reduced pressure at 60 ° C to obtain a polyfluorene imine powder (J) of Comparative Synthesis Example 1. The polyimide has a fluorene imidation rate of 63%, a number average molecular weight of 19,800, and a weight average molecular weight of 65,400.

<Comparative Synthesis Examples 2 to 4> According to the method of Comparative Synthesis Example 1, the materials or ratios were changed as shown in Tables 1 and 2, and the polyfluorene imine powders (K) to (M) of Comparative Synthesis Examples 2 to 4 were obtained.

<Example 1> (1) NMP (54.0 g) was added to the polyfluorene imine powder (A) (6.0 g) obtained in Synthesis Example 1, and the mixture was stirred at 70 ° C. for 40 hours to be dissolved. BCS (40.0 g) was added to this solution, and the liquid crystal alignment agent [1] of Example 1 was obtained by stirring for 5 hours. No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment agent, and it was confirmed that the resin component was uniformly dissolved.

<Examples 2 to 9> According to the method of Example 1, the polyimide material was changed as shown in Table 3 to obtain the alignment treatment agents [2] to [9] of Examples 2 to 9. No abnormality such as turbidity or precipitation was observed in these liquid crystal alignment agents, and it was confirmed that the resin component was uniformly dissolved.

<Example 10> (1) NMP (54.0 g) was added to the polyimide powder (C) (3.0 g) and polyimide powder (F) (3.0 g) obtained in Synthesis Examples 3 and 6, and 70 It stirred at 40 degreeC for 40 hours, and was made to melt | dissolve. BCS (40.0 g) was added to this solution and stirred for 5 hours, whereby the liquid crystal alignment agent [10] of Example 10 was obtained. No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment agent, and it was confirmed that the resin component was uniformly dissolved.

<Comparative Example 1 to Comparative Example 4> According to the method of Example 1, the polyimide material was changed as shown in Table 3 to obtain the alignment treatment agents [11] to [14] of Comparative Examples 1 to 3. No abnormality such as turbidity or precipitation was observed in these liquid crystal alignment agents, and it was confirmed that the resin component was uniformly dissolved.

＜ Production of liquid crystal cell ＞ The liquid crystal alignment agents obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were spin-coated on the ITO surface of a 3 × 4 cm glass substrate with ITO, and were heated at 70 ° C using a hot plate After firing for 1 minute and 30 seconds, firing was performed using an infrared heating furnace at 230 ° C. for 20 minutes to produce a polyimide-coated substrate having a film thickness of 100 nm.

Two polyimide-coated substrates were prepared by the above method, and a 4 μm spherical spacer was sprayed on the liquid crystal alignment film surface of one of the substrates, and then a thermosetting sealing material was printed thereon (Kyoritsu Chemical Co., Ltd. XN-1500T). Next, the surface on the side where the liquid crystal alignment film is formed on the other substrate is used as the inner side, and the sealing material is hardened to produce an empty cell after bonding to the previous substrate. A liquid crystal MLC-3023 (trade name, manufactured by Merck) containing a polymerizable compound for PSA was injected into the empty cell by a reduced pressure injection method to prepare a liquid crystal cell. The voltage retention of the liquid crystal cell was measured.

Next, in a state where a DC voltage of 15 V is applied to the liquid crystal cell, the outside of the liquid crystal cell is irradiated with UV of 10 J / cm ² (also referred to as 1) passing through a band-pass filter of 365 nm. Times PSA processing). The UV illuminance was measured using UV-MO3A manufactured by ORC.

Then, for the purpose of inactivating the unreacted polymerizable compound remaining in the liquid crystal cell, a UV (UV lamp: FLR40SUV32 / A-1) 30 minutes (also referred to as 2 PSA treatments). Then, the voltage holding ratio was measured.

<Evaluation of voltage holding ratio> (1) Using the liquid crystal cell prepared above, in a hot air circulation oven at 60 ° C., a voltage of 1 V was applied for 60 μs, and then the voltage after 1667 msec was measured, and the voltage holding ratio was calculated as the voltage holding ratio. For measurement of the voltage holding ratio, VHR-1 manufactured by TOYO Corporation was used.

<Evaluation of High Temperature and High Humidity Resistance> (1) The liquid crystal cell produced above was left to stand for 7 days in a thermo-hygrostat (PR-2KP, manufactured by ESPEC) at a temperature of 85 ° C and a humidity of 85%, and the voltage retention rate was measured. The difference between the voltage retention rate measured here and the voltage retention rate after 2 PSA treatments is taken as the VHR change amount.

As shown in Table 3, Comparative Examples 1 to 4 had the liquid crystal cells exposed to high temperature and high humidity. Therefore, the VHR change amount was 52% or more, but in Examples 1 to 5, the HR change amount was confirmed to be 50%. The following minor changes. In addition, in Examples 1 to 5, it was confirmed that the liquid crystal cells produced by using the liquid crystal alignment agents [1] to [3], [6] to [10] of Examples 1 to 3 and 6 to 10, especially Under high temperature and high humidity, high voltage retention can be ensured after a long time.

From the above, it can be seen that the liquid crystal alignment film formed using the liquid crystal alignment agents [1] to [10] of Examples 1 to 10, and the liquid crystal display element obtained by using the liquid crystal alignment film are mounted on a vehicle, for example. The car navigation or instrumentation, the display unit of industrial equipment or measurement equipment installed outside the house can ensure a high voltage retention rate even after long-term use under high temperature and high humidity.

Of course, the liquid crystal alignment film formed by using the liquid crystal alignment agents [1] to [10] of Examples 1 to 10, and the liquid crystal display element obtained by using the liquid crystal alignment film, even if not at high temperature and high humidity In addition, high voltage retention can be ensured over a long period of time. As described above, the liquid crystal alignment film formed by using the liquid crystal alignment agents [1] to [10] of Examples 1 to 10 and the liquid crystal display element obtained by using the liquid crystal alignment film are compared with the comparative example. In addition, the initial voltage holding ratio is also high, that is, high driving reliability can be ensured.

Claims (11)

A liquid crystal alignment agent comprising: a diamine having a structure having the following formula (1) and at least one kind of two having a side chain structure selected from the group represented by the following formulae [S1] to [S3] A polymer of a diamine component of an amine and a polyimide precursor obtained from a tetracarboxylic acid component and / or a polyimide of a polyimide precursor of the polyimide precursor, (In formula (1), A ¹ and A ⁵ each independently represent a single bond or an alkylene group having 1 to 5 carbon atoms, A ² and A ⁴ each independently represent an alkylene group having 1 to 5 carbon atoms, and A ³ represents carbon An alkylene or cycloalkylene having a number of 1 to 6, B ¹ and B ² each independently represent a single bond, -O-, -NH-, -N (CH ₃ )-, -CO-, -COO-,- OCO-, -CONH-, -NHCO-, -CON (CH ₃ )-or -N (CH ₃ ) CO-; D ₁ represents a protecting group substituted by a hydrogen atom by heat, a is 0 or 1; A ² And A ³ (when a is 1), A ³ and A ⁴ (when a is 1), or A ² and A ⁴ (when a is 0), they are not bonded to each other, and * indicates a part bonded to another base ) (In the formula [S1], X ¹ and X ² each independently represent a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH ₃ )- , -NH-, -O-, -COO-, -OCO-, or-((CH ₂ ) _a1 -A ₁ ) _m1- , where each of the complex numbers a1 is an integer from 1 to 15, and each of the complex numbers A _{1 is} Independently represents an oxygen atom or -COO-; m ₁ is 1-2, and G ¹ and G ² each independently represent a divalent aromatic group selected from a carbon number of 6 to 12 or a divalent alicyclic group of 3 to 8 carbons A divalent cyclic group of the formula group, and any hydrogen atom on the aforementioned cyclic group may be selected from the group consisting of an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and 1 to 3 carbon atoms. Substituted by at least one of a group consisting of a fluoroalkyl group, a fluorine-containing alkoxy group having 1 to 3 carbon atoms or a fluorine atom, m and n are each independently an integer of 0 to 3, and the total of m and n is 1 to 4; R ¹ represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxy alkyl group having 2 to 20 carbon atoms, and any hydrogen forming R ¹ may be substituted by fluorine) (In formula [S2], X ³ represents a single bond, -CONH-, -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO-, or -OCO- ; R ² represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, and any hydrogen forming R ² may be substituted by fluorine) (In the formula [S3], X ⁴ represents -CONH-, -NHCO-, -O-, -COO-, or -OCO-; and R ³ represents a structure having a steroid skeleton). For example, the liquid crystal alignment agent of claim 1, wherein the aforementioned diamine having the structure of the formula (1) is a structure having the structure represented by the following formula (1 "), . For example, the liquid crystal alignment agent of claim 1, wherein the aforementioned diamine having the structure of the formula (1) is at least one of the groups represented by the following formulae (1-1) to (1-18), . The liquid crystal alignment agent according to claim 1, wherein the diamine component is a diamine having a side chain structure represented by the aforementioned formula [S1]. For example, the liquid crystal alignment agent of claim 1, wherein the diamine having the side chain structure represented by the aforementioned formula [S1] is at least one of the groups represented by the following formulas [S1-x1] to [S1-x7], (In the formulas [S1-x1] to [S1-x7], R ¹ is the same as that in the formula [S1], and X ^p represents-(CH ₂ ) _a- (a is an integer from 1 to 15), -CONH- , -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO-, or -OCO-; A ₁ represents an oxygen atom or -COO- * (with "* ”Bond with (CH ₂ ) _a2 ); A ₂ represents an oxygen atom or * -COO- (bond with“ * ”and (CH ₂ ) _a2 bond); a ₁ is 0 or An integer of 1, a ₂ is an integer of 2 to 10, and Cy represents 1,4-cyclohexyl or 1,4-phenylene). For example, the liquid crystal alignment agent of claim 1, wherein R ^{2 in} the diamine having the side chain structure represented by the aforementioned formula [S2] is an alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. For example, the liquid crystal alignment agent of claim 1, wherein the diamine having a side chain structure represented by the aforementioned formula [S3] is a diamine represented by the following formula [S3-x], (In formula [S3-x], X represents formula [X1] or [X2], and Col represents at least one selected from the group consisting of formulas [Col1] to [Col4], and G represents formula [G1] Or [G2], * indicates the part bonded to other bases). For example, the liquid crystal alignment agent of claim 1, wherein the aforementioned diamine component contains a diside chain diamine having a structure of the following formula [1], (In the formula [1], X represents a single bond, -O-, -C (CH ₃ ) _2- , -NH-, -CO-,-(CH ₂ ) _m- , -SO ₂ -and any of them The divalent organic group formed by the combination, m is an integer of 1 to 8, and two Y's each independently represent at least one of the foregoing formulas [S1] to [S3]). A liquid crystal alignment film is formed by using the liquid crystal alignment agent according to any one of claims 1 to 8. A liquid crystal display element is provided with the liquid crystal alignment film according to claim 9. A method for manufacturing a liquid crystal alignment film, which has the following steps: 步骤 a step of applying the liquid crystal alignment agent according to any one of claims 1 to 8 on a substrate to form a coating film; 的 a step of firing the aforementioned coating film ; A step of subjecting the fired film to an alignment treatment.