JP2019008170A - Polymer for liquid crystal alignment film, liquid crystal alignment film, liquid crystal display element, liquid crystal display, optical anisotropic material, optical anisotropic film and optical device - Google Patents

Abstract

To provide a liquid crystal alignment film that suppresses image persistence due to an AC voltage and can impart reliability.SOLUTION: A polymer for a liquid crystal alignment film is provided, which contains a structural unit A represented by formula (1) below and a structural unit B represented by formula (2) below. In formula (1), Mrepresents any group selected from a set consisting of specific chemical formulae (M-1) to (M-6); Arepresents a photoreactive group that can induce photodimerization or photoisomerization; and when the polymer contains a plurality of structural units A, a plurality of Mand a plurality of Amay be the same or different from each other. In formula (2), Mrepresents any group selected from a set consisting of specific chemical formulae (M-1) to (M-6); Arepresents a crosslinking group; and when the polymer contains a plurality of structural units B, a plurality of Mand a plurality of Amay be the same or different from each other.SELECTED DRAWING: None

Description

  The present invention relates to a polymer for a liquid crystal alignment film, a liquid crystal alignment film, a liquid crystal display element, a liquid crystal display, an optical anisotropic body, an optical anisotropic film, and an optical device.

  In liquid crystal display elements, the alignment of liquid crystal molecules has a great influence on the display characteristics, and various alignment methods have been studied, and can be broadly classified into a vertical alignment type and a horizontal alignment type. In both the vertical alignment type and the horizontal alignment type, a liquid crystal alignment film is used to align the liquid crystal molecules, and the alignment direction and pretilt angle of the liquid crystal molecules using the alignment film are controlled by display characteristics. Is important to improve.

  There is a rubbing method as a method for imparting a liquid crystal alignment film with a force for regulating the alignment of liquid crystals (alignment regulating force). In the rubbing method, a film made of polyimide or the like is formed on a substrate, and the film is rubbed with a rubbing cloth to impart alignment regulating force and control the alignment direction and pretilt angle. However, it is difficult to form a precise alignment division structure by the rubbing method, and there is another problem such as generation of static electricity and impurity components due to friction, and reduction in contrast due to light leakage from alignment film scratches caused by cloth contact. There is a problem.

  As a method for imparting alignment regulating force to the liquid crystal alignment film, a photo-alignment method is known in addition to the rubbing method (see Patent Document 1). In the photo-alignment method, a precise alignment division structure can be easily formed by changing the light irradiation pattern, and alignment treatment can be performed on the film in a non-contact manner. Is unlikely to occur, and contrast is unlikely to decrease. Therefore, the photo-alignment method is expected to solve the above-described problems and improve display characteristics.

  As a material for the liquid crystal alignment film in the photo-alignment method, photochemically such as a compound having a photochemically isomerizable site such as an azobenzene derivative (see Patent Document 2), a cinnamic acid derivative, a coumarin derivative, and a chalcone derivative. Compounds having a crosslinkable site (see Patent Documents 3, 4 and 5) are known.

Japanese Patent No. 2668271 Japanese Patent Laid-Open No. 5-232473 JP-A-6-287453 JP-A-9-118717 Special table 2002-517605 gazette

  In a liquid crystal display element or the like having a liquid crystal alignment film, it is known that a problem called image sticking (AC image sticking) occurs after an AC (alternating current) voltage is applied for a long time. AC image sticking means that liquid crystal molecules do not completely return to the alignment direction defined by the liquid crystal alignment film even if the voltage is not applied after the AC voltage is applied to the liquid crystal molecules. It is a failure mode that causes it.

  AC image sticking occurs when the pretilt angle of the liquid crystal molecules at a location where an AC voltage is applied gradually changes from the initial value, thereby increasing the transmittance at that location. Therefore, image sticking tends to increase as the voltage application time increases. For these reasons, liquid crystal display elements and the like are required to have a low AC burn-in progress from the initial state even after an AC voltage is applied for a long period of time, and to have excellent reliability against AC burn-in.

  The present invention relates to a liquid crystal alignment film capable of suppressing AC image sticking of a liquid crystal display element or the like and imparting reliability to the liquid crystal display element or the like with respect to AC image sticking, a liquid crystal alignment film polymer used for the liquid crystal alignment film, It is an object to provide a liquid crystal display element, an optical anisotropic body, an optically anisotropic film, an optical device, and a liquid crystal display using the liquid crystal display element.

  As a result of intensive studies to solve the above problems, the present inventors have found that a liquid crystal display element using a liquid crystal alignment film containing a cured product of a polymer for a liquid crystal alignment film into which a crosslinkable group has been introduced is an AC. It has been found that the reliability against burn-in is excellent, and the present invention has been completed.

（式（１）中、Ｍ^１は、下記式（Ｍ−１）〜（Ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^１は、光二量化又は光異性化可能な光反応性基を示し、ポリマー中に複数の構造単位Ａを含む場合、複数のＭ^１は互いに同一であっても異なっていてもよく、複数のＡ^１は互いに同一であっても異なっていてもよい。）

（式（２）中、Ｍ^２は、下記式（Ｍ−１）〜（Ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^２は架橋性基を示し、ポリマー中に複数の構造単位Ｂを含む場合、複数のＭ^２は互いに同一であっても異なっていてもよく、複数のＡ^２は互いに同一であっても異なっていてもよい。）

（式（Ｍ−１）〜（Ｍ−６）中、破線はＡ^１又はＡ^２への結合を示し、Ｒ^１０、Ｒ^１３及びＲ^１４は、水素原子又はメチル基を示し、Ｒ^１１は、水素原子、カルボキシル基又はカルバモイル基を示し、Ｒ^１２は、水素原子、メチル基又はカルボキシメチル基を示す。） That is, the polymer for a liquid crystal alignment film according to one aspect of the present invention includes a structural unit A represented by the following formula (1) and a structural unit B represented by the following formula (2).

(In formula (1), M ¹ represents any group selected from the group consisting of groups represented by the following formulas (M-1) to (M-6), and A ¹ represents photodimerization or light. In the case where the photoreactive group is isomerizable and includes a plurality of structural units A in the polymer, a plurality of M ¹ may be the same as or different from each other, and a plurality of A ¹ are the same as each other May be different.)

(In formula (2), M ² represents any group selected from the group consisting of groups represented by the following formulas (M-1) to (M-6), and A ² represents a crosslinkable group. When the polymer contains a plurality of structural units B, the plurality of M ² may be the same or different from each other, and the plurality of A ² may be the same or different from each other.

(In the formulas (M-1) to (M-6), a broken line represents a bond to A ¹ or A ² , R ¹⁰ , R ¹³ and R ¹⁴ represent a hydrogen atom or a methyl group, and R ¹¹ represents And represents a hydrogen atom, a carboxyl group or a carbamoyl group, and R ¹² represents a hydrogen atom, a methyl group or a carboxymethyl group.)

  According to the polymer for a liquid crystal alignment film, it is possible to obtain a liquid crystal alignment film that can suppress the progress of AC image sticking of a liquid crystal display element or the like and can give the liquid crystal display element or the like reliability to AC image sticking.

  In one embodiment, the crosslinkable group comprises at least one group selected from the group consisting of alkoxymethylol groups, methylol groups, and blocked isocyanate groups. In this case, there is a tendency that the effect of imparting reliability to AC image sticking is further improved.

In one embodiment, the polymer for a liquid crystal alignment film includes, as the structural unit A, a structural unit in which A ¹ is a photoreactive group capable of photodimerization. In this case, the obtained liquid crystal alignment film tends to be excellent in alignment regulating force.

In one embodiment, the polymer for a liquid crystal alignment film includes, as the structural unit A, a structural unit in which A ¹ is a photoreactive group that can be photoisomerized. When the polymer for liquid crystal alignment film includes, as the structural unit A, a structural unit in which A ¹ is a photoreactive group capable of photodimerization and a structural unit in which A ¹ is a photoreactive group capable of photoisomerization, The obtained liquid crystal alignment film tends to be more excellent in alignment regulating force.

  In one embodiment, the photoreactive group capable of photodimerization is a group having an α, β-unsaturated carbonyl structure, and the photoreactive group capable of photoisomerization is a group having an azo structure. In this case, the obtained liquid crystal alignment film tends to be more excellent in alignment regulating force.

  In one embodiment, the group having an α, β-unsaturated carbonyl structure is a group having a structure derived from cinnamic acid, chalcone, coumarin or a derivative thereof. In this case, the obtained liquid crystal alignment film tends to be more excellent in alignment regulating force.

  In one embodiment, the proportion of the structural unit represented by the formula (1) in the total of the structural unit A and the structural unit B is 80 to 99.9 mol%, and the proportion of the structural unit B is 0.1 to 20 Mol%. In this case, the obtained liquid crystal alignment film tends to be excellent in alignment regulation and tends to be further excellent in the effect of imparting reliability to AC image sticking.

（式（３）中、Ｍ^３は、上記式（Ｍ−１）〜（Ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^３は架橋促進基を示し、ポリマー中に複数の構造単位Ｃを含む場合、複数のＭ^３は互いに同一であっても異なっていてもよく、複数のＡ^３は互いに同一であっても異なっていてもよい。） In one embodiment, the polymer for a liquid crystal alignment film further includes a structural unit C represented by the formula (3). In this case, there is a tendency that the effect of imparting reliability to AC image sticking is further improved.

(In formula (3), M ³ represents any group selected from the group consisting of groups represented by the above formulas (M-1) to (M-6), and A ³ represents a crosslinking promoting group. When the polymer contains a plurality of structural units C, the plurality of M ³ may be the same or different from each other, and the plurality of A ³ may be the same or different from each other.

（式（Ｍ−７）及び式（Ｍ−６）中、破線はＡ^１、Ａ^２又はＡ^３への結合を示し、Ｒ^１５及びＲ^１６は、水素原子又はメチル基を示す。） In one embodiment, M ¹ , M ² and M ³ each independently represent a group represented by the following formula (M-7) or (M-8). In this case, the obtained liquid crystal alignment film tends to be excellent in alignment regulating force, and tends to be more excellent in the effect of imparting reliability to AC image sticking.

(In the formula (M-7) and the formula (M-6), a broken line represents a bond to A ¹ , A ² or A ³ , and R ¹⁵ and R ¹⁶ represent a hydrogen atom or a methyl group.)

  In one embodiment, the proportion of the structural unit A in the total of the structural unit A, the structural unit B, and the structural unit C is 80 to 99.8 mol%, and the proportion of the structural unit B is 0.1 to 10 mol%. Yes, the proportion of the structural unit C is 0.1 to 10 mol%. In this case, the obtained liquid crystal alignment film tends to be excellent in alignment regulating force, and tends to be more excellent in the effect of imparting reliability to AC image sticking.

In one embodiment, the polymer for liquid crystal alignment film includes, as the structural unit A, a structural unit in which A ¹ is substituted with a crosslinking promoting group A ³ .

In one embodiment, the proportion of the structural unit A in the total of the structural unit A, the structural unit B, and the structural unit C is 80 to 99.9 mol%, and the proportion of the structural unit B is 0.1 to 10 mol%. In addition, the total of the proportion of the structural unit A and the proportion of the structural unit C in which A ¹ is substituted with a crosslinking promoting group is 0.1 to 90 mol%. In this case, the obtained liquid crystal alignment film tends to be excellent in alignment regulating force, and tends to be more excellent in the effect of imparting reliability to AC image sticking.

In one embodiment, a crosslinking accelerator group A ³ is a carboxyl group. In this case, there is a tendency that the effect of imparting reliability to AC image sticking is further improved.

  The liquid crystal aligning film which concerns on 1 side of this invention contains the hardened | cured material of the said polymer for liquid crystal aligning films. According to this liquid crystal alignment film, a liquid crystal display element excellent in reliability against AC image sticking can be obtained.

  The liquid crystal display element which concerns on one side of this invention is equipped with the said liquid crystal aligning film. This liquid crystal display element is excellent in reliability against AC image sticking.

  A liquid crystal display according to one aspect of the present invention includes the liquid crystal display element.

  An optical anisotropic body according to one aspect of the present invention is an optical anisotropic body composed of a polymer of a polymerizable liquid crystal composition, and the polymerizable liquid crystal molecules in the polymerizable liquid crystal composition are converted into the liquid crystal alignment film. It is characterized by having been oriented using.

  An optically anisotropic film according to one aspect of the present invention includes the liquid crystal alignment film.

  The optical device which concerns on one side of this invention is equipped with the phase difference plate which has the said liquid crystal aligning film.

  According to the present invention, a liquid crystal alignment film that can suppress the progress of AC image sticking of a liquid crystal display element or the like and can impart reliability to the liquid crystal display element or the like with respect to AC image sticking, a liquid crystal alignment film polymer used for the liquid crystal alignment film, A liquid crystal display element, an optical anisotropic body, an optically anisotropic film, an optical device using the liquid crystal alignment film, and a liquid crystal display using the liquid crystal display element can be provided.

It is a schematic diagram which shows the crosslinked structure of the hardened | cured material of the polymer for liquid crystal aligning films which concerns on this embodiment. It is a graph which shows the VT curve used for evaluation of the reliability with respect to AC image sticking.

  Hereinafter, although the preferable example of this invention is demonstrated, this invention is not limited to these examples. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention.

（式（１）中、Ｍ^１は、下記式（Ｍ−１）〜（Ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^１は、光二量化又は光異性化可能な光反応性基を示し、ポリマー中に複数の構造単位Ａを含む場合、複数のＭ^１は互いに同一であっても異なっていてもよく、複数のＡ^１は互いに同一であっても異なっていてもよい。）

（式（２）中、Ｍ^２は、下記式（Ｍ−１）〜（Ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^２は架橋性基を示し、ポリマー中に複数の構造単位Ｂを含む場合、複数のＭ^２は互いに同一であっても異なっていてもよく、複数のＡ^２は互いに同一であっても異なっていてもよい。なお、Ｍ^２は、Ｍ^１と互いに同一であっても異なっていてもよい。）

（式（Ｍ−１）〜（Ｍ−６）中、破線はＡ^１又はＡ^２への結合を示し、Ｒ^１０、Ｒ^１３及びＲ^１４は、水素原子又はメチル基を示し、Ｒ^１１は、水素原子、カルボキシル基又はカルバモイル基を示し、Ｒ^１２は、水素原子、メチル基又はカルボキシメチル基を示す。） (Polymer for liquid crystal alignment film)
The polymer for liquid crystal alignment film according to the present embodiment (hereinafter also simply referred to as “polymer”) includes a structural unit A represented by the following formula (1) and a structural unit B represented by the following formula (2).

(In formula (1), M ¹ represents any group selected from the group consisting of groups represented by the following formulas (M-1) to (M-6), and A ¹ represents photodimerization or light. In the case where the photoreactive group is isomerizable and includes a plurality of structural units A in the polymer, a plurality of M ¹ may be the same as or different from each other, and a plurality of A ¹ are the same as each other May be different.)

(In formula (2), M ² represents any group selected from the group consisting of groups represented by the following formulas (M-1) to (M-6), and A ² represents a crosslinkable group. When the polymer includes a plurality of structural units B, the plurality of M ² may be the same or different from each other, and the plurality of A ² may be the same or different from each other. ² may be the same as or different from M ^1. )

(In the formulas (M-1) to (M-6), a broken line represents a bond to A ¹ or A ² , R ¹⁰ , R ¹³ and R ¹⁴ represent a hydrogen atom or a methyl group, and R ¹¹ represents And represents a hydrogen atom, a carboxyl group or a carbamoyl group, and R ¹² represents a hydrogen atom, a methyl group or a carboxymethyl group.)

  The polymer according to the present embodiment is used for forming a liquid crystal alignment film (photo-alignment film) by a photo-alignment method. According to the polymer according to the present embodiment, it is possible to obtain a liquid crystal alignment film that can suppress the progress of AC image sticking of a liquid crystal display element or the like and can provide the liquid crystal display element or the like with reliability against AC image sticking. The cause of this is not clear, but the present inventors presume as follows.

Usually, when a liquid crystal alignment film is formed using a polymer for liquid crystal alignment film, first, a film containing the polymer for liquid crystal alignment film is formed on a substrate, and then the film is irradiated with light to control alignment force (anisotropic) Liquid crystal alignment film is obtained. On the other hand, in this embodiment, in addition to the above operation, it crosslinkable groups A ² each other in the structural unit B is a crosslinking reaction by performing processing such as heating to the film after the light irradiation. That is, in the liquid crystal alignment film formed using the polymer according to the present embodiment, as shown in FIG. 1, the polymers in the liquid crystal alignment film (for example, polymer 1 and polymer 2 in FIG. 1) are cross-linked. firm crosslinked structure by crosslinking through sexual group a ² is formed. In this embodiment, since the polymer in the liquid crystal alignment film (cured product of the polymer for liquid crystal alignment film) has such a crosslinked structure, it is presumed that excellent reliability against AC image sticking can be obtained in a liquid crystal display element or the like. .

  The proportion of the structural unit A and the structural unit B in the polymer is not particularly limited, but the proportion of the structural unit A in the total of the structural unit A and the structural unit B is 80 to 99.9 mol%, and the structural unit B It is preferable that the ratio is 0.1-20 mol%. In this case, there is a tendency that the alignment control force and the reliability against AC image sticking are further improved. From the same viewpoint, the proportion of the structural unit A in the total of the structural unit A and the structural unit B is 85 to 99.9 mol%, and the proportion of the structural unit B is 0.1 to 15 mol%. More preferably, the proportion of the structural unit A is 90 to 99.9 mol%, and the proportion of the structural unit B is further preferably 0.1 to 10 mol%.

The polymer according to this embodiment may have a cross-linking promoting group A ³ in its structure. When the polymer according to the present embodiment has the crosslinking accelerating group A ³ in its structure, it tends to be more excellent in the effect of imparting reliability to AC image sticking. This is presumed to be because the crosslinking structure in the liquid crystal alignment film becomes denser as a result of the crosslinking reaction of the crosslinking group A ² being promoted by the crosslinking promoting group A ³ . In the present specification, the crosslinking accelerator group means a functional group having a function of promoting the crosslinking reaction of the crosslinkable groups A ^2. Crosslinking accelerator group A ³ does not include a photo-dimerization or photoisomerizable photoreactive groups.

（式（３）中、Ｍ^３は、上記式（Ｍ−１）〜（Ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^３は架橋促進基を示し、ポリマー中に複数の構造単位Ｃを含む場合、複数のＭ^３は互いに同一であっても異なっていてもよく、複数のＡ^３は互いに同一であっても異なっていてもよい。なお、Ｍ^３は、Ｍ^１及びＭ^２と互いに同一であっても異なっていてもよい。） For example, the polymer according to the present embodiment may further include a structural unit C represented by the following formula (3).

(In formula (3), M ³ represents any group selected from the group consisting of groups represented by the above formulas (M-1) to (M-6), and A ³ represents a crosslinking promoting group. When the polymer contains a plurality of structural units C, the plurality of M ³ may be the same or different from each other, and the plurality of A ³ may be the same or different from each other. ³ may be the same as or different from M ¹ and M ² .

In addition, for example, the polymer according to the present embodiment may include, as the structural unit A, a structural unit in which A ¹ is substituted with a crosslinking accelerating group A ³ . That is, the photoreactive group A ¹ in the structural unit A may have a crosslinking promoting group A ³ in the structure. The polymer according to this embodiment may include only the structural unit in which A ¹ is substituted with the crosslinking promoting group A ³ as the structural unit A, and the structural unit in which A ¹ is not substituted with the crosslinking promoting group A ^3. And a structural unit in which A ¹ is substituted with a crosslinking promoting group A ³ .

In addition, for example, the polymer according to the present embodiment may further include a structural unit A, and further include a structural unit A in which A ¹ is substituted with a crosslinking promoting group A ³ . In this case, a plurality of cross-promoting group A ³ may be the being the same or different.

  When the polymer according to the present embodiment includes the structural unit C, the proportion of the structural unit A in the total of the structural unit A, the structural unit B, and the structural unit C is 80 to 99.8 mol%. It is preferable that the ratio is 0.1 to 10 mol% and the ratio of the structural unit C is 0.1 to 10 mol%. In this case, the obtained liquid crystal alignment film tends to be excellent in alignment regulating force, and tends to be more excellent in the effect of imparting reliability to AC image sticking. From the same viewpoint, the proportion of the structural unit A is 85 to 99.8 mol%, the proportion of the structural unit B is 0.1 to 10 mol%, and the proportion of the structural unit C is 0.1 to 5 mol%. It is more preferable that the proportion of the structural unit A is 90 to 99.8 mol%, the proportion of the structural unit B is 0.1 to 5 mol%, and the proportion of the structural unit C is 0.1 to 5 mol%. More preferably, it is mol%.

When the polymer according to this embodiment includes, as the structural unit A, a structural unit in which A ¹ is substituted with the crosslinking accelerating group A ³ , the structural unit occupies the total of the structural unit A, the structural unit B, and the structural unit C. The proportion and structure of the structural unit A in which the proportion of A is 80 to 99.9 mol%, the proportion of the structural unit B is 0.1 to 10 mol%, and A ¹ is substituted with the crosslinking promoting group A ³ The total proportion of units C is preferably 0.1 to 90 mol%. In this case, the obtained liquid crystal alignment film tends to be excellent in alignment regulating force, and tends to be more excellent in the effect of imparting reliability to AC image sticking. From the same viewpoint, the proportion of the structural unit A is 85 to 99.8 mol%, the proportion of the structural unit B is 0.1 to 10 mol%, and A ¹ is substituted with the crosslinking promoting group A ³ . More preferably, the sum of the proportion of the structural unit A and the proportion of the structural unit C is 0.1 to 5 mol%, the proportion of the structural unit A is 90 to 99.8 mol%, and the proportion of the structural unit B is More preferably, the total of the proportion of the structural unit A and the proportion of the structural unit C in which A ¹ is substituted with the crosslinking promoting group A ³ is 0.1 to 5 mol%. .

  The arrangement order and randomness of each structural unit in the polymer are not particularly limited. The polymer according to this embodiment is preferably a random copolymer from the viewpoint of easily obtaining the effects of the present invention.

  The polymer according to this embodiment may consist of only the structural unit A, the structural unit B, and the structural unit C, and may include other structural units other than the structural unit A, the structural unit B, and the structural unit C. When the polymer according to the present embodiment includes other structural units other than the structural unit A, the structural unit B, and the structural unit C, the ratio of the structural unit A to the total structural units in the polymer is 80 to 99.9 mol%. 85-99.9 mol%, 90-99.9 mol%, 80-99.8 mol%, 85-99.8 mol%, or 90-99.8 mol%, and the total structure in the polymer The proportion of the structural unit B in the unit may be 0.1 to 20 mol%, 0.1 to 15 mol%, 0.1 to 10 mol% or 0.1 to 5 mol%. The proportion of the structural unit C in the structural unit may be 0.1 to 10 mol% or 0.1 to 5 mol%.

  As a weight average molecular weight of the polymer which concerns on this embodiment, it is preferable that it is 5000-500000, It is more preferable that it is 20000-400000, It is still more preferable that it is 100,000-300000. In addition, a weight average molecular weight shows the value measured by gel permeation chromatography, and represents it with a standard polystyrene conversion value.

  Next, each structural unit will be described in detail.

（式（４）中、Ｍａ^１は、下記式（ｍ−１）〜（ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^１は光二量化又は光異性化可能な光反応性基を示す。）

（式（５）中、Ｍａ^２は、下記式（ｍ−１）〜（ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^２は架橋性基を示す。）

（式（６）中、Ｍａ^３は、下記式（ｍ−１）〜（ｍ−６）で表される基からなる群より選ばれるいずれかの基を示し、Ａ^３は架橋促進基を示す。）

（式（ｍ−１）〜（ｍ−６）中、破線はＡ^１、Ａ^２又はＡ^３への結合を示し、Ｒ^１０、Ｒ^１１、Ｒ^１２、Ｒ^１３及びＲ^１４は、式（Ｍ−１）、（Ｍ−３）及び（Ｍ−４）におけるＲ^１０、Ｒ^１１、Ｒ^１２、Ｒ^１３及びＲ^１４と同様に定義される官能基を示す。） The structural unit A, the structural unit B, and the structural unit C are respectively a compound (monomer) a represented by the following formula (4), a compound (monomer) b represented by the following formula (5), and the following. It is a structural unit derived from the compound (monomer) c represented by the formula (6).

(In formula (4), Ma ¹ represents any group selected from the group consisting of groups represented by the following formulas (m-1) to (m-6), and A ¹ represents photodimerization or photoisomerism. Photoreactive group that can be converted to

(In formula (5), Ma ² represents any group selected from the group consisting of groups represented by the following formulas (m-1) to (m-6), and A ² represents a crosslinkable group. .)

(In formula (6), Ma ³ represents any group selected from the group consisting of groups represented by the following formulas (m-1) to (m-6), and A ³ represents a crosslinking promoting group. .)

(In the formulas (m-1) to (m-6), a broken line represents a bond to A ¹ , A ² or A ³ , and R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are represented by the formula (M -1) represents a functional group defined similarly to R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ in (M-3) and (M-4).

Ma ¹ , Ma ² and Ma ³ are derived from a compound selected from, for example, (meth) acrylic acid, crotonic acid, maleic acid, maleamic acid, citraconic acid, itaconic acid, styrene, methylstyrene, (meth) acrylamide and maleimide A group having the structure:

（式（Ｍ−７）及び式（Ｍ−８）中、破線はＡ^１への結合を示し、Ｒ^１５及びＲ^１６は、水素原子又はメチル基を示す。） <Structural unit A>
M ¹ is preferably a group represented by the following formula (M-7) or (M-8) from the viewpoint that the obtained liquid crystal alignment film is excellent in alignment regulating force.

(In the formula (M-7) and the formula (M-8), the broken line represents a bond to A ¹ , and R ¹⁵ and R ¹⁶ represent a hydrogen atom or a methyl group.)

A ¹ is a functional group having a function of imparting alignment regulating force to a film containing a polymer for a liquid crystal alignment film by dimerization or isomerization by light irradiation. A ¹ is preferably a photoreactive group capable of photodimerization from the viewpoint that the obtained liquid crystal alignment film is excellent in alignment regulating force. When the polymer according to this embodiment includes a plurality of structural units A, the polymer has a structural unit having a photoreactive group capable of photodimerization as A ¹ and a structure having a photoreactive group capable of photoisomerization as A ^1. Units. In this case, the orientation regulating force tends to be further improved.

[Photoreactive group capable of photodimerization]
As the photoreactive group capable of photodimerization, a group having an α, β-unsaturated carbonyl structure is preferable from the viewpoint of excellent alignment regulating power. Examples of the group having an α, β-unsaturated carbonyl structure include a group having a structure derived from cinnamic acid, chalcone, coumarin, or derivatives thereof. Among these, a group having a structure derived from cinnamic acid or a cinnamic acid derivative is preferable from the viewpoint that the obtained liquid crystal alignment film is further excellent in alignment regulating force. A group having a structure derived from cinnamic acid or a cinnamic acid derivative has a structure in which one of the hydrogen atoms on the benzene ring is substituted with a group having an α, β-unsaturated carbonyl structure.

（式（１ａ）中、Ｅは２価の基を示し、Ｒａは１価の基を示し、ｇは０〜５の整数を示す。Ｒａが複数ある場合（例えばｇが２以上である場合）、複数のＲａは互いに同一であっても異なっていてもよい。）

（式（１ｂ）中、Ｅは２価の基を示し、Ｒａ及びＲｂは１価の基を示し、ｇは０〜４の整数を示す。ＲａとＲｂとは互いに同一であっても異なっていてもよい。Ｒａが複数ある場合（例えばｇが２以上である場合）、複数のＲａは互いに同一であっても異なっていてもよい。） When the photodimerizable group is a group having a structure derived from cinnamic acid or a cinnamic acid derivative, the structural unit A is obtained by directly bonding the group having an α, β-unsaturated carbonyl structure to M ¹ to form the benzene A structural unit (see the following formula (1a)) having an α, β-unsaturated carbonyl structure on the M ¹ group side with respect to a ring (a benzene ring substituted by a group having an α, β-unsaturated carbonyl structure). A group having an α, β-unsaturated carbonyl structure may be bonded to the M ¹ group via the benzene ring (a benzene ring substituted by a group having an α, β-unsaturated carbonyl structure); It may be a structural unit having an α, β-unsaturated carbonyl structure on the side opposite to the M ¹ group (see the following formula (1b)).

(In formula (1a), E represents a divalent group, Ra represents a monovalent group, and g represents an integer of 0 to 5. When there are a plurality of Ras (for example, when g is 2 or more). The plurality of Ra may be the same or different from each other.)

(In Formula (1b), E represents a divalent group, Ra and Rb represent a monovalent group, and g represents an integer of 0 to 4. Ra and Rb may be the same or different from each other. When there are a plurality of Ras (for example, when g is 2 or more), the plurality of Ras may be the same or different.

（式（１ｃ）中、Ｅは２価の基を示し、Ｒａは１価の基を示し、ｇ１及びｇ２は０〜５の整数を示す。複数のＭ^１は互いに同一であっても異なっていてもよい。複数のＥは互いに同一であっても異なっていてもよい。Ｒａが複数ある場合、複数のＲａは互いに同一であっても異なっていてもよい。） When the photoreactive group capable of photodimerization is a group having a structure derived from cinnamic acid or a cinnamic acid derivative, the structural unit A has a benzene ring (α, β-unsaturated carbonyl as shown in the above formula (1b)). It is preferable to have an α, β-unsaturated carbonyl structure on the side opposite to the M ¹ group with respect to the benzene ring substituted by a group having a structure. When the structural unit A has an α, β-unsaturated carbonyl structure on the M ¹ group side with respect to the benzene ring, the functional unit containing a benzene ring bonded to a group having an α, β-unsaturated carbonyl structure. The group is rotated 90 ° by the photodimerization reaction to form, for example, a structure represented by the following formula (1c). In this case, the orientation regulating force works in a direction substantially perpendicular to the direction in which the original orientation regulating force works (the direction in which the two structural units A are combined), and the orientation regulating force may be weakened. On the other hand, when the structural unit A has an α, β-unsaturated carbonyl structure on the side opposite to the M ¹ group with respect to the benzene ring, the functional group containing the benzene ring does not rotate, so the structural unit A Compared with the case where has an α, β-unsaturated carbonyl structure on the M ¹ group side with respect to the benzene ring, there is a tendency that the alignment regulating force of the obtained liquid crystal alignment film is more excellent.

(In the formula (1c), E represents a divalent group, Ra represents a monovalent group, and g1 and g2 represent integers of 0 to 5. A plurality of M ¹ may be the same or different. The plurality of E may be the same or different from each other, and when there are a plurality of Ra, the plurality of Ra may be the same or different from each other.

  The photoreactive group capable of photodimerization preferably has a cyano group at its end. In this case, the obtained liquid crystal alignment film is excellent in controlling the alignment and pretilt angle of the liquid crystal, and may have a high voltage holding ratio (VHR). In addition, since the obtained liquid crystal alignment film has a high voltage holding ratio (VHR) and is excellent in controlling the alignment and pretilt angle of the liquid crystal, the liquid crystal display element and the optical anisotropic body are excellent in display quality and reliability. Can be efficiently manufactured. Note that the voltage holding ratio (VHR) is the degree to which the voltage applied to each pixel in the liquid crystal display device is held for a certain period of time (for example, one general frame in the liquid crystal display device, 16.7 msec). It is an indicator that shows.

The photoreactive group capable of photodimerization may be, for example, a group represented by the following formula (I).

In the formula (I), a broken line indicates a bond to M ¹ or Ma ¹ . p is an integer of 0 to 4, and is preferably 0 or 1.

Sp ¹ is a spacer group and represents a single bond, a linear or branched alkylene group having 1 to 40 carbon atoms, or a group represented by the following formula (Sa). One methylene group present in the alkylene group or two or more methylene groups not adjacent to each other are represented by —O—, —COO—, —OCO—, —CH═CH—, —CF═CF—, _{-CF 2 O -, - OCF 2} -, - CF 2 CF 2 -, - C≡C -, - CO -, - S -, - Si (CH 3) 2 -O-Si (CH 3) 2 -, ^{-NR 21 -, - NR 21 -CO} -, - CO-NR 21 -, - NR 21 -CO-O -, - O-CO-NR 21 -, - NR 21 -CO-NR 21 -, - CH = CH—, —C≡C— or —O—CO—O— (wherein R ²¹ independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) may be substituted. -CH 2 in the alkylene group _- At least one hydrogen atom is a fluorine atom, a chlorine atom, a hydroxy , Or it may be substituted with a cyano group. In addition, it excludes when the group connected to Sp ¹ and Sp ¹ has a hetero atom and the hetero atoms are connected to each other.

In the formula (Sa), the broken line on the left indicates a bond to M ¹ or Ma ¹ , and the broken line on the right indicates a bond to Z ²¹ . p1 and q1 each independently represent 0 or 1.

Z ¹¹ , Z ¹² and Z ¹³ are a single bond, —O—, — (CH ₂ ) _u1 — (wherein u1 is an integer of 1 to 20), —OCH ₂ —, —CH ₂ O—, Selected from the group consisting of —COO—, —OCO—, —CH═CH—, —CF═CF—, —CF ₂ O—, —OCF ₂ —, —CF ₂ CF ₂ —, and —C≡C—. At least one divalent linking group, one methylene group present in Z ¹¹ , Z ¹² and Z ¹³ or two or more methylene groups not adjacent to each other is independently —O—, —CO—, —CO—O—, —O—CO—, —Si (CH ₃ ) ₂ —O—Si (CH ₃ ) ₂ —, —NR ²² —, —NR ²² —CO—, —CO—NR ^{22 -, - NR 22 -CO-} O -, - O-CO-NR 22 -, - NR 22 -CO-NR 22 -, - C H═CH—, —C≡C— or —O—CO—O— (wherein R ²² independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) may be substituted. . Z ¹¹ , Z ¹² and Z ¹³ may be the same as or different from each other.

A ¹¹ and A ¹² are trans-1,4-cyclohexylene groups (one methylene group present in this group or two or more methylene groups not adjacent to each other are —O—, —NH—, or -S-), 1,4-phenylene group (one or more -CH = present in this group may be replaced by -N =), 1,4-cyclohexenylene Group, 2,5-thiophenylene group, 2,5-furylene group, 1,4-bicyclo [2.2.2] octylene group, naphthalene-1,4-diyl group, naphthalene-2,6-diyl group, A group selected from the group consisting of a decahydronaphthalene-2,6-diyl group and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, each of which is unsubstituted or one or more Hydrogen atom is fluorine atom, chlorine source , A cyano group, may be substituted by an alkyl group or an alkoxy group. A ¹¹ and A ¹² may be the same as or different from each other.

Sp ¹ is preferably an alkylene group having 1 to 20 carbon atoms or an oxyalkylene group having 1 to 20 carbon atoms, and preferably 6 to 14 carbon atoms from the viewpoint of excellent alignment regulating power of the obtained liquid crystal alignment film. Are more preferably an alkylene group having 6 to 14 carbon atoms, and further preferably an alkylene group having 8 to 12 carbon atoms or an oxyalkylene group having 8 to 12 carbon atoms.

D ¹ and D ² represent — (Z ²³ —A ²² ) _k —C (═O) — or a single bond. When D ¹ is — (Z ²³ —A ²² ) _k —C (═O) —, D ² is a single bond, and when D ¹ is a single bond, D ² is —C (═O) —. ^(a 22 ^-Z _{23) k} - is. k is an integer of 0 to 3, and is preferably 0 or 1.

Z ²¹ , Z ²² and Z ²³ are each independently a single bond, —O—, — (CH ₂ ) _u2 — (wherein u2 is an integer of 1 to 20), —OCH ₂ —, — CH ₂ O—, —COO—, —OCO—, —CH═CH—, —CF═CF—, —CF ₂ O—, —OCF ₂ —, —CF ₂ CF ₂ — and —C≡C—. 1 shows at least one divalent linking group selected from the group.

One methylene group or two or more methylene groups not adjacent to each other present in the Z ²³ are independently, -O -, - CO -, - CO-O -, - O-CO -, - Si (CH ₃ ) ₂ —O—Si (CH ₃ ) ₂ —, —NR ²³ —, —NR ²³ —CO—, —CO—NR ²³ —, —NR ²³ —CO—O—, —O—CO—NR ²³ —, —NR ²³ —CO—NR ²³ —, —CH═CH—, —C≡C— or —O—CO—O— (wherein R ²³ is independently a hydrogen atom or a carbon number of 1 to 5 represents an alkyl group). When there are a plurality of Z ²² and Z ²³ (for example, when p and k are 2 or more), the plurality of Z ²² may be the same as or different from each other, and the plurality of Z ²³ are the same as each other May be different.

A ²¹ and A ²² are defined in the same manner as A ¹¹ and A ¹² described above. When there are a plurality of A ²¹ and A ²² (for example, when p and k are 2 or more), the plurality of A ²¹ may be the same as or different from each other, and the plurality of A ²² are the same as each other May be different.

A ²¹ is a 1,4-phenylene group (one or two or more —CH═ present in this group may be replaced by —N═) from the viewpoint of excellent orientation regulating force. preferable. One or more hydrogen atoms of A ²¹ are preferably substituted with an alkoxy group, and more preferably substituted with a methoxy group or an ethoxy group.

A ²² is preferably any group of a trans-1,4-cyclohexylene group, a 2,6-naphthylene group, or a 1,4-phenylene group from the viewpoint of excellent alignment regulating power. The hydrogen atoms of these groups may be unsubstituted or one or more hydrogen atoms may be substituted with a fluorine atom, a methyl group or a methoxy group.

  X and Y each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 20 carbon atoms, and the hydrogen atom present in the alkyl group is substituted with a fluorine atom. In the case where one methylene group or two or more methylene groups that are not adjacent to each other are present in the alkyl group, one methylene group or two or more methylene groups that are not adjacent to each other are represented by —O— , -CO-O-, -O-CO- and / or -CH = CH-.

  X and Y are preferably hydrogen atoms. When X and Y are hydrogen atoms, the voltage holding ratio in the liquid crystal alignment film can be improved. Further, in order to perform photo-alignment using light having a longer wavelength on the liquid crystal alignment film, X and Y are preferably a fluorine atom, a chlorine atom or a cyano group.

Z represents a group represented by the following formula (Ia) or a group represented by the following formula (Ib).

Wherein (Ia) and (Ib), a dashed line indicates a bond to ^{D 2.} R ¹ and R ² each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 50 carbon atoms, and one methylene group in R ¹ and R ² or adjacent to each other. No two or more methylene groups are —O—, —CO—, —CO—O—, —O—CO—, —CO—NH—, —NH—CO—, —NCH ₃ —, —CH═CH—. , —CF═CF— and —C≡C—, each of which may be substituted with one or more —CH ₂ — groups in R ¹ and R ² , Independently, it may be substituted with a cycloalkyl group having 3 to 8 ring members, and the hydrogen atom in R ¹ and R ² is substituted with an alkyl group having 1 to 20 carbon atoms, a cyano group or a halogen atom. May be.

In the formula (Ia) or (Ib), R ¹ is a linear or branched alkyl group having 1 to 30 carbon atoms (one methylene group in the alkyl group or two or more methylene groups not adjacent to each other). May be substituted with —O—, —CO—, —CO—O—, —O—CO—, —CO—NH—, —NH—CO—, —NCH ₃ —. One or two or more —CH ₂ — groups may each independently be substituted with a cycloalkyl group having 3 to 8 ring members, and the hydrogen atom in the alkyl group has 1 to 20 carbon atoms. An alkyl group, a cyano group or a halogen atom, and R ² is a linear or branched alkyl group having 1 to 30 carbon atoms (one or two or more in the alkyl group). Each methylene group independently represents a cycloalkyl having 3 to 8 ring members; A hydrogen atom in the alkyl group may be unsubstituted or substituted with an alkyl group having 1 to 20 carbon atoms, a cyano group, or a halogen atom). Is preferred.

Z may be, for example, a group represented by the following formula (Id), (Ie) or (If).

Wherein (Id), (Ie) and (the If), the broken line indicates a bond to ^{D 2.} R ³ represents an alkylene group having 1 to 30 carbon atoms, when there are a plurality of R ^3, a plurality of R ³ may be be the same or different from each other. R ⁴ represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms.

When there is one methylene group or two or more methylene groups not adjacent to each other in R ³ and R ⁴ , one methylene group or two or more methylene groups not adjacent to each other is —O—, —CO—, —CO—O—, —O—CO—, —CO—NH—, —NH—CO—, —NCH ₃ —, —CH═CH—, —CF═CF— and / or —C≡. It may be substituted with C-, and the hydrogen atom present in R ³ and R ⁴ may be substituted with an alkyl group having 1 to 20 carbon atoms, a cyano group, or a halogen atom.

In the formula (Id), (Ie) or (If), the alkylene group having 1 to 30 carbon atoms represented by R ³ may be linear, branched or cyclic, linear or branched The methylene group present in the alkylene group may be replaced with a cycloalkylene group having 3 to 8 ring members. R ³ is preferably an alkylene group having 1 to 3 carbon atoms or an alkenylene group having 1 to 3 carbon atoms. In the above formula (Id), (Ie) or (If), -R ³ -CN is more preferably a group represented by the following formulas (W-1) to (W-4), and (W-1 ) Or (W-2).

In the formula (Id), (Ie) or (If), R ³ is preferably a group represented by the following formula (Ig).

In the formula (Ig), a broken line represents a bond to an oxygen atom or a nitrogen atom, and * represents a bond to a cyano group. W ¹ represents a methylene group (the hydrogen atom present in this group may be substituted with an alkyl group having 1 to 5 carbon atoms), —CO—O— or —CO—NH—. R ⁵ represents an alkylene group having 1 to 20 carbon atoms. When one alkylene group or two or more methylene groups not adjacent to each other are present in the alkylene group, one methylene group or 2 Two or more non-adjacent methylene groups are —O—, —CO—, —CO—O—, —O—CO—, —CO—NH—, —NH—CO—, —NCH ₃ —. It may be replaced with. R ⁶ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and the hydrogen atom present in the alkyl group may be substituted with a fluorine atom or a chlorine atom.

In the formula (If), the alkyl group having 1 to 30 carbon atoms represented by R ⁴ may be linear, branched or cyclic, and a methyl group in the linear or branched alkyl group. May be substituted with a cycloalkyl group having 3 to 8 ring members, and when a methylene group is present in a linear or branched alkyl group, a cycloalkylene having 3 to 8 ring members It may be replaced with a group.

In formula (If), in order to further improve the alignment regulating force of the liquid crystal alignment film, R ⁴ is preferably a linear or cyclic alkyl group having 2 to 8 carbon atoms, and 2 to 4 carbon atoms. The linear or cyclic alkyl group is more preferable, and a linear alkyl group having 2 to 4 carbon atoms is particularly preferable. In order to improve the voltage holding ratio in the liquid crystal alignment film, R ⁴ is preferably a linear or cyclic alkyl group having 1 to 12 carbon atoms. In order to reduce the residual charge in the liquid crystal alignment film, R ⁴ is preferably a linear or cyclic alkyl group having 1 to 6 carbon atoms.

[Photoreactive group capable of photoisomerization]
As the photoreactive group capable of photoisomerization, a group having an azo structure is preferable from the viewpoint of excellent alignment regulating power.

The photoreactive group capable of photoisomerization may be, for example, a group having a structure represented by the following formula (II).

In the formula (II), a broken line indicates a bond to M ¹ or Ma ¹ . q and r are each independently an integer of 0 to 4, and s is an integer of 1 to 3. q is preferably 0 or 1, and r is preferably 0 or 1. When there are a plurality of Qs (for example, when s is 2 or more), the plurality of Qs may be the same as or different from each other.

Sp ² represents a spacer group. Sp ² is defined in the same manner as Sp ¹ . When Z ²⁴ is a single bond, Sp ² is preferably the alkylene group or a structure represented by the above formula (Sa). In the formula (Sa), the broken line on the left indicates a bond to M ² or Ma ² , and the broken line on the right indicates a bond to Z ²⁴ .

When Sp ² is an alkylene group, the number of carbon atoms of the alkylene group is preferably 2 to 20, more preferably 3 to 15, and still more preferably 4 to 10. These suitable spacer groups can improve the VHR (voltage holding ratio) of a liquid crystal display device including a liquid crystal alignment film using the polymer according to the present embodiment.

Z ²⁴ and Z ²⁵ are defined in the same manner as Z ²¹ and Z ²² . When there are a plurality of Z ²⁵ (for example, when q is 2 or more), the plurality of Z ²⁵ may be the same as or different from each other.

A ²³ and A ²⁴ are defined in the same manner as A ²¹ and A ²² . When there are a plurality of A ²³ and A ²⁴ (for example, when q and r are 2 or more), the plurality of A ²³ may be the same as or different from each other, and the plurality of A ²⁴ are the same as each other May be different.

Q is a hydrogen atom or a group represented by the following formula (QX).

In the formula (QX), a broken line indicates a bond to a carbon atom, and S _aa is selected from the group consisting of a single bond, an alkylene group having 1 to 3 carbon atoms, —O—, —COO—, and —O—CO—. that represents at least one group, V _a represents at least one group selected from the group consisting of alkyl radicals, alkyl ether group, a naphthyl group and an anthryl group having 1 to 7 carbon atoms. When S _aa is the alkylene group and V _a is the alkyl group, the total number of carbon atoms of S _aa and V _a is 7 or less.

One methylene group constituting the alkyl group or two or more methylene groups not adjacent to each other are independently -O-, -CO-, -CO-O-, -O-CO-, -Si (CH ₃ ) ₂ —O—Si (CH ₃ ) ₂ —, —NR ²⁴ —, —NR ²⁴ —CO—, —CO—NR ²⁴ —, —NR ²⁴ —CO—O—, —O—CO—NR ²⁴ — , —NR ²⁴ —CO—NR ²⁴ — (wherein R ²⁴ independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), —CH═CH—, —C≡C—, —O It may be substituted with one or more substituents selected from —CO—O— and a divalent ring structure. Examples of the divalent ring structure include an aromatic cyclic group, a heterocyclic group, and a cyclic alkyl group. The divalent ring structure preferably substitutes the —CH ₂ — group at the end of the alkyl group. That is, the divalent ring structure is preferably a monovalent ring structure that replaces the terminal methyl group of the alkyl group. As the divalent ring structure and the monovalent ring structure, any two or one hydrogen atoms constituting benzene, naphthalene and anthracene are removed, and the divalent or 1-valent ring structure has two or one bond. A valent ring structure is preferred.

  One or more hydrogen atoms bonded to the group represented by the formula (QX) may be substituted with a fluorine atom, a chlorine atom, a cyano group, a hydroxyl group, a carboxyl group, an amide group, a fluorine, a sulfide group or a nitro group. Good.

The group represented by the formula (QX) is preferably the following group from the viewpoint that the obtained liquid crystal alignment film is excellent in alignment regulating force and further excellent in the effect of imparting reliability to AC image sticking. That is, if _{V a} is an alkyl group having a carbon number of 1 to _{7, S aa} is preferably a single bond. The alkyl group is preferably linear or branched, and more preferably linear. If V _a is an alkyl ether group, Examples of the alkyl ether group, methyl ether, ethyl ether; having a linear or branched, propyl ether, butyl ether, pentyl ether, hexyl ether, oxy ether, heptyl ether, and the like are preferable. When V _a is a naphthyl group or an anthryl group, S _aa is preferably an alkyl group having 1 to 3 carbon atoms, and S _aa is more preferably an alkyl group having 1 or 2 carbon atoms. When Va is _a naphthyl group, it is preferable that the 1st-position carbon atom of the naphthyl group is bonded to _Saa . If V _a is a anthryl group (anthracenyl), 1-position or 9-position carbon atom of the anthryl groups is preferred to bind to S _aa, the carbon atom at the 9-position of the anthryl group is bonded to the S _aa It is more preferable.

In the present embodiment, A ¹ may have a crosslinking promoting group A ³ in its structure. In this case, there is a tendency that the effect of imparting reliability to AC image sticking is further improved. A ¹ having a crosslinking accelerating group A ³ is preferably a photoreactive group capable of photodimerization, and is derived from cinnamic acid, chalcone, coumarin or a derivative thereof from the viewpoint of further improving the reliability of AC image sticking. More preferably, the group has a structure derived from cinnamic acid or a cinnamic acid derivative. From the same viewpoint, it is particularly preferable that A ¹ has A ³ at its terminal. Details of the crosslinking accelerator group A ³ will be described later.

（式（Ｉ２）中、破線はＭ^１又はＭａ^１への結合を示し、Ｓｐ^１、Ｚ^２１、Ａ^２１、Ｚ^２２、Ｘ、Ｙ及びｐは、式（Ｉ）と同様に定義され、Ａ^３は架橋促進基を示す。） A ¹ substituted with the crosslinking promoting group A ³ may be, for example, a group represented by the following formula (I2).

(In the formula (I2), a broken line indicates a bond to M ¹ or Ma ¹ , and Sp ¹ , Z ²¹ , A ²¹ , Z ²² , X, Y and p are defined in the same manner as in the formula (I). ³ represents a crosslinking promoting group.

Of the structural units according to the present embodiment, the structural unit having the photoreactive group A ¹ capable of photodimerization is particularly preferably a structural unit represented by the following formula (1A).

In formula (1A), v1 is an integer of 2 to 12, t is an integer of 0 or 1, Z ¹⁴ represents a single bond, —COO— or —OCO—, W ¹¹ represents a hydrogen atom, a fluorine atom , A methyl group, a methoxy group, an ethyl group or an ethoxy group, and W ¹² represents the following formula (W ¹² -1) to (W ¹² -4) or a hydrogen atom.

In the formula (1A), Z ¹⁴ is preferably —COO—. Further, from the viewpoint of ensuring good alignment with the irradiation of small polarized UV light, v1 is preferably from 8 to 12, preferably t is 1, W ¹¹ is preferably a methyl group or a methoxy group. W ¹² is particularly preferably a group represented by (W ¹² -1).

（式（１Ｂ）中、ｖ２は２〜１２の整数であり、ｓは１〜３の整数であり、Ｑ^１は、シアノ基、カルボキシル基、ヒドロキシル基、炭素数１〜１０のアルキル基、水素原子を示し、Ｑ^１が複数ある場合（ｓが２以上である場合）、複数のＱ^１は互いに同一であっても異なっていてもよい。アルキル基は直鎖状又は分岐状のいずれであってもよい。） Of the structural units according to the present embodiment, the structural unit having the photoreactive group A ¹ capable of photoisomerization is particularly preferably a structural unit represented by the following formula (1B).

(In formula (1B), v2 is an integer of 2 to 12, s is an integer of 1 to 3, Q ¹ is a cyano group, a carboxyl group, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, hydrogen When an atom is present and there are a plurality of Q ¹ (when s is 2 or more), the plurality of Q ¹ may be the same or different from each other, and the alkyl group may be linear or branched. May be.)

<Structural unit B>
M ² is preferably a group represented by the above formula (M-7) or (M-8) from the viewpoint that the obtained liquid crystal alignment film is excellent in alignment regulating force. However, the dashed line in formula (M-7) and formula (M-8) represents the binding of ^{A 2.}

A ² is a crosslinkable group different from A ^1, and is a functional group that can form a cross-linked structure by reacting with other crosslinkable groups. A ² is, for example, a thermally crosslinkable group that reacts with other crosslinkable groups by heat. In the present embodiment, upon formation of the liquid crystal alignment film, the crosslinking structure in the liquid crystal alignment film is formed by a crosslinking reaction of the crosslinkable group A ^2, excellent reliability for the AC image sticking can be obtained.

Examples of A ² include functional groups including an alkoxymethylol group (—CH ₂ OR ¹⁷ (wherein R ¹⁷ represents an alkyl group)), a methylol group (—CH ₂ OH), a blocked isocyanate group, and the like. . Here, the blocked isocyanate group means an isocyanate group protected (blocked) by a blocking agent (protecting group) that is dissociated by heat treatment. That is, when the polymer for liquid crystal alignment film has a blocked isocyanate group, the blocking agent is dissociated by heat treatment of the polymer for liquid crystal alignment film to generate an isocyanate group, and this isocyanate group causes a crosslinking reaction. Examples of the blocking agent include a dimethyltripyrazole group, a diethyl malonate group, a methyl ethyl ketoxime group, and a caprolactam group. A ² preferably contains at least one group selected from the group consisting of an alkoxymethylol group and a methylol group from the viewpoint of further improving the effect of imparting reliability to AC image sticking. The alkoxymethylol group is preferably a methoxymethylol group, a methylol group or a blocked isocyanate group, more preferably a methoxymethylol group. Incidentally, when the liquid crystal alignment film polymer comprises a structural unit B having a blocked isocyanate group as A ^2, the liquid crystal alignment film polymer, further includes a structural unit B having a functional group capable of reacting with an isocyanate group as A ² May be. A carboxyl group is mentioned as a functional group which can react with an isocyanate group. Is a functional group functional group capable of reacting with isocyanate groups correspond to crosslink promoting group A ³ such as a carboxyl group, a structural unit B contained in the liquid crystal alignment film polymer may accelerate the crosslinking reaction by the functional group cross In the case of having the functional group A ² , the structural unit having the functional group is also included in the structural unit C.

（式（２Ａ）中、Ｒ^１８は水素原子又はメチル基を示す。） The structural unit B according to this embodiment is particularly preferably a structural unit represented by the following formula (2A).

(In the formula (2A), R ¹⁸ represents a hydrogen atom or a methyl group.)

<Structural unit C>
M ³ is preferably a group represented by the above formula (M-7) or (M-8) from the viewpoint that the obtained liquid crystal alignment film is excellent in alignment regulating force. However, the dashed line in formula (M-7) and formula (M-8) represents the binding to ^{A 3.}

Crosslinking accelerator group A ³ has a function of promoting the crosslinking reaction of the crosslinkable groups A ^2. For example, when the crosslinking reaction of the crosslinkable group A ² is a hydrolysis reaction, it may be a functional group that functions as a catalyst (for example, an acid catalyst) that promotes the hydrolysis reaction. However, when A ³ is a hydrogen atom and the structural unit C includes a crosslinking promoting group, the hydrogen atom is also included in the crosslinking promoting group A ³ . For example, when M ³ is a group represented by the formula (M-7), A ³ may be a hydrogen atom.

Examples of the crosslinking accelerating group A ³ include a functional group represented by the following formula (IV).

The broken line in the formula (IV) is a bond, and indicates a bond to any atom in M ³ or Ma ³ or A ¹ , for example. s is an integer of 0-3. Z ³¹ is defined in the same manner as Z ²¹ , Z ²² , Z ²⁴ and Z ^25, and A ³¹ is defined in the same manner as A ²¹ , A ²² , A ²³ and A ²⁴ . When there are a plurality of Z ³¹ and A ³¹ , the plurality of Z ³¹ may be the same as or different from each other, and the plurality of A ³¹ may be the same as or different from each other. L represents at least one group selected from the group consisting of a sulfonic acid group, a carboxyl group, and a hydroxyl group.

Crosslinking accelerator group A ^3, from the viewpoint of ease of control when the crosslinking reaction by heating, preferably has a carboxyl group.

The structural unit C according to this embodiment is particularly preferably a structural unit represented by the following formula (4A) or a structural unit represented by the following formula (4B).

In the formulas (4A) and (4B), R ¹⁹ represents a hydrogen atom or a methyl group. In formula (4A), v3 is an integer of 2 to 12, and L ¹ represents a carboxyl group or a hydroxyl group.

(Synthesis of polymer for liquid crystal alignment film)
The method for synthesizing the polymer according to the present embodiment is not particularly limited. For example, the polymer can be obtained by polymerizing the monomer a, the monomer b, and optionally the monomer c.

  When the polymer according to this embodiment is synthesized, a known polymerization initiator can be used in combination with the polymerization mode of the polymerization functional group. As the polymerization initiator, for example, a polymerization initiator described in a known publication “Synthesis and Reaction of Polymers (Edited by Polymer Society, Kyoritsu Shuppan)” can be used.

  Examples of the thermal polymerization initiator in radical polymerization include azo compounds such as azobisisobutyronitrile, peroxides such as benzoyl peroxide, and the like.

  Examples of the photopolymerization initiator include aromatic ketone compounds such as benzophenone, Michler's ketone, xanthone and thioxanthone; quinone compounds such as 2-ethylanthraquinone; acetophenone, trichloroacetophenone, 2-hydroxy-2-methylpropiophenone, 1- Acetophenone compounds such as hydroxycyclohexyl phenyl ketone, benzoin ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone; diketone compounds such as benzyl and methylbenzoylformate; 1-phenyl-1,2-propane Acyl oxime ester compounds such as dione-2- (O-benzoyl) oxime; acyl phosphine oxide compounds such as 2,4,6-trimethylbenzoyl diphenylphosphine oxide; Tetramethyl thiuram, sulfur compounds such as dithiocarbamate; organic peroxides such as benzoyl peroxide; azo compounds such as azobisisobutyronitrile; organic sulfonium salt compound; iodonium salt compound; and phosphonium compounds.

  Examples of the thermal polymerization initiator in cationic polymerization include aromatic sulfonium salt compounds.

  The addition amount of a polymerization initiator is 0.1-10 mass% with respect to the total mass of the polymerizable composition containing the monomer a, the monomer b, and the monomer c depending on the case. Is more preferable, 0.1 to 6% by mass is more preferable, and 0.1 to 3% by mass is further preferable.

  The polymer which concerns on this embodiment can be obtained by refine | purifying a product, after performing a polymerization reaction in reaction containers, such as glass and stainless steel.

  The polymerization reaction may be performed in the presence of a solvent. Examples of the solvent include benzene, toluene, xylene, ethylbenzene, pentane, hexane, heptane, octane, cyclohexane, cycloheptane, methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether. 2-butanone, acetone, tetrahydrofuran, γ-butyrolactone, N-methyl-pyrrolidone, dimethyl sulfoxide and dimethylformamide. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more types.

In the synthesis of the polymer according to this embodiment, the above-described polymerization composition or a monomer solution containing the polymerization composition and a solvent is applied on a substrate, and the solvent is dried and removed as necessary. Then, the photoreactive group A ¹ And a method in which the polymerization reaction is carried out by heating or light irradiation under the condition that the reaction of the crosslinkable group A ² does not proceed.

(Liquid crystal alignment film)
The film or layer containing the polymer according to the present embodiment has a photoreactive group A ¹ that can be photodimerized or photoisomerized, so that the alignment regulating force on the liquid crystal molecules is irradiated by irradiating light. And thermal stability of the orientation regulating force can be obtained together. In the present embodiment, with respect to films or layers obtained by light irradiation, by performing a process to crosslinking crosslinkable group A ² (e.g. heat treatment), the reliability and application to the AC burn-in liquid crystal display devices, etc. An obtained liquid crystal alignment film (photo-alignment film) can be obtained. The liquid crystal alignment film thus obtained contains a cured product of the polymer for liquid crystal alignment film. Here, the cured product of the polymer for liquid crystal alignment film means that photoreactive group A ¹ capable of photodimerization or photoisomerization in the polymer for liquid crystal alignment film undergoes a photoreaction and crosslinkable group A ² undergoes a crosslinking reaction. The reaction product obtained in this way.

The liquid crystal alignment film according to this embodiment can be obtained, for example, by the following manufacturing method. That is, the liquid crystal alignment film manufacturing method includes a step of forming a resin layer containing a polymer according to the present embodiment on a substrate (resin layer forming step), and a step of irradiating the resin layer with light (light irradiation step). And a step of crosslinking reaction of the crosslinkable group A ² (crosslinking step).

  The resin layer is obtained by preparing a polymer solution containing the polymer according to the present embodiment and a solvent, and coating the solution on a substrate. The polymer which concerns on this embodiment may be used individually by 1 type, and may be used combining 2 or more types of polymers.

  The coating can be performed by a method such as spin coating, die coating, gravure coating, flexographic printing, and ink jet printing.

  As the solvent used in the polymer solution, a solvent that dissolves the polymer according to this embodiment and other components that are optionally used, which will be described later, and does not react with them is preferably used. Examples of the solvent include 1,1,2-trichloroethane, N-methylpyrrolidone, butoxyethanol, γ-butyrolactone, ethylene glycol, polyethylene glycol monomethyl ether, propylene glycol, 2-pyrrolidone, N, N-dimethylformamide, phenoxyethanol, Tetrahydrofuran, dimethyl sulfoxide, methyl isobutyl ketone, cyclohexanone and the like can be mentioned. These solvents may be used alone or in combination of two or more.

  The polymer solution may contain other components as necessary. As other components, a siloxane derivative for improving adhesion with a glass substrate, a leveling agent for improving the leveling property of a coating film, an ultraviolet absorber and a light stabilizer for improving light resistance, Examples thereof include an antioxidant and a polymerization inhibitor for improving the storage stability of the material.

  The polymer solution may contain another polymer different from the polymer according to the present embodiment as long as the effects of the present invention are not impaired. The other polymer may be, for example, a polymer including any one of the structural unit A or the structural unit B, may be a polymer including the structural unit A and the structural unit C, and the structural unit B and It may be a polymer containing the structural unit C. When the other polymer contains a photoreactive group or a crosslinkable group capable of photodimerization, in the light irradiation step or the crosslinking step, the polymer according to the present embodiment and the other polymer react (photoreaction or crosslinking reaction), A cured product of a polymer mixture containing the polymer according to this embodiment and another polymer is obtained. In this case, the obtained liquid crystal alignment film contains a cured product of a polymer mixture containing the polymer according to the present embodiment and another polymer as a cured product of the polymer for the liquid crystal alignment film. The blending ratio of the polymer according to the present embodiment and the other polymer may be appropriately adjusted according to the composition of the other polymer, and may be 1: 1 (mass ratio), for example.

  When the other polymer contains the structural unit A, the proportion of the structural unit A in the total structural units in the polymer is 80 to 99.9 mol%, 85 to 99.9 mol%, 90 to 99.9 mol%, It may be 80-99.8 mol%, 85-99.8 mol%, or 90-99.8 mol%. When the other polymer includes the structural unit B, the proportion of the structural unit B in all the structural units in the polymer is 0.1 to 20 mol%, 0.1 to 15 mol%, 0.1 to 10 mol%, or It may be 0.1 to 5 mol%. When another polymer contains the structural unit C, the ratio of the structural unit C to the whole structural unit in a polymer may be 0.1-10 mol% or 0.1-5 mol%.

  The solid content concentration of the polymer solution (for example, the content of the polymer according to this embodiment) is preferably 0.5 to 10% by mass, and the method of coating the solution on the substrate, viscosity, volatility, etc. It can be selected as appropriate in consideration.

  Examples of the substrate include glass, silicon, polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and triacetyl cellulose. These substrates may have an electrode layer (conductive layer), a color filter layer, a liquid crystal alignment layer, or the like formed on the surface.

Examples of the electrode layer (conductive layer) include an ITO film made of Cr, Al, In ₂ O ₃ —SnO ₂ , a NESA film made of SnO _2, and the like. Photo-etching can be applied to patterning these electrode layers. The electrode layer may be patterned by a method using a mask when forming the electrode layer.

  In the above method for producing a liquid crystal alignment film, when a substrate on which a liquid crystal alignment film is formed in advance is used, by further forming the photo-alignment film according to the present embodiment on the substrate, the ability to control the alignment direction and the alignment angle can be obtained. It can also be reapplied to the substrate.

In the present embodiment, after applying the polymer solution, a step of removing the solvent may be provided as necessary. It is preferable to remove the solvent by heating the coated surface. Drying temperature, when the crosslinkable group A ² is a thermally crosslinkable groups, the crosslinking reaction crosslinkable group A ² may be a temperature not proceed. The drying temperature is preferably 50 to 300 ° C, more preferably 80 to 150 ° C, and further preferably 90 ° C to 120 ° C. The drying time is preferably 2 to 200 minutes, and more preferably 1 to 100 minutes.

  In the method for producing a liquid crystal alignment film, a monomer solution containing the monomer a, the monomer b, and optionally the monomer c and a solvent may be used instead of the polymer solution. That is, after the monomer solution is applied on the substrate, the resin layer may be formed by preparing the polymer by polymerizing the monomer by heating or light irradiation of the coating film. In this case, the preparation of the polymer and the application of the orientation regulating force may be performed simultaneously.

  As the solvent used for the monomer solution, in addition to the solvents that can be used for the polymerization reaction described above, those exemplified as the solvent used for the polymer solution can be used.

  When the preparation of the polymer and the application of the alignment regulating force are performed at the same time, heat and light may be used together, or two or more kinds of light having different wavelengths may be used in combination. In this case, it is preferable to contain a polymerization initiator in the monomer solution. After coating, the solvent may be removed and non-polarized light may be irradiated to prepare a polymer by photopolymerization.

  In the case of preparing a polymer by thermal polymerization, the heating temperature is not particularly limited as long as it is sufficient for the polymerization to proceed, but it is generally about 50 to 250 ° C. and about 70 to 200 ° C. Further preferred.

When preparing a polymer by photopolymerization, it is preferable to use non-polarized ultraviolet rays for light irradiation. Irradiation energy ^is preferably ^{10mJ / cm 2 ~8000mJ / cm 2} , further preferably ^{40mJ / cm 2 ~5000mJ / cm 2} . The illuminance is preferably 2~1000mW / cm ^2, more preferably 4~500mW / cm ^2. The irradiation wavelength preferably has a peak at 250 to 450 nm.

In the step of irradiating the resin layer with light, the resin layer containing the polymer according to the present embodiment is irradiated with linearly polarized light from the normal direction of the resin layer surface and / or non-polarized light or linearly polarized light from the oblique direction. Do. By this photoirradiation, the photoreaction of the photoreactive group A ¹ capable of photodimerization (for example, dimerization reaction of cinnamic acid derivative) can be performed to impart alignment regulating force to the resin layer. In this embodiment, the resin layer after the light irradiation is referred to as a liquid crystal alignment film precursor.

The alignment regulating force of the liquid crystal alignment film can be evaluated, for example, by measuring the azimuth anchoring energy at the interface between the liquid crystal phase containing liquid crystal molecules and the liquid crystal alignment film. Azimuthal anchoring energy at the interface between the liquid crystal alignment film and the liquid crystal phase is preferably 100 .mu.J / ^{m 2} or more, more preferably 150μJ / ^{m 2} or more, still be at 250μJ / ^{m 2} or more preferable.

  In order to give a desired pretilt angle, it is preferable to irradiate the surface of the resin layer with linearly polarized light from an oblique direction. The oblique direction refers to an inclination with respect to a direction parallel to the substrate surface, and the inclination angle is referred to as a pretilt angle. The pretilt angle can be appropriately adjusted according to the purpose of use. When used as an alignment film for vertical alignment, generally, the pretilt angle is preferably 70 to 89.8 °. Further, when used as an alignment film for horizontal alignment, generally, the pretilt angle is preferably 1 to 7 °. In particular, in the IPS mode, the pretilt angle is preferably 0 to 1 °.

  As the light source, for example, a xenon lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, or the like can be used. Linearly polarized light can be obtained by using a polarizing filter, a polarizing prism, or the like for the light from these light sources. Further, the wavelength range of the ultraviolet light and visible light obtained from such a light source may be limited using an interference filter, a color filter, or the like.

Irradiation energy ^is preferably ^{15mJ / cm 2 ~500mJ / cm 2} , further preferably ^{20mJ / cm 2 ~300mJ / cm 2} . More preferably illuminance is 2~500mW / cm ^2, further preferably 5~300mW / cm ^2.

The light irradiated to the resin layer, for advancing the photoreaction of the photoreactive group A ^1, for example, it can be an ultraviolet and visible light includes light of a wavelength of 150 to 800 nm. Among these, ultraviolet rays of 270 nm to 450 nm are particularly preferable. Monomer a (especially cinnamic acid derivative) having a photoreactive group A ¹ if has a naphthylene group, by ultraviolet irradiation of 270Nm～450nm, the efficiency of the application of the alignment regulating force can be further enhanced. Such an effect is considered to be because the naphthylene group absorbs ultraviolet rays of 270 nm to 450 nm well.

  The thickness of the liquid crystal alignment film is preferably about 10 to 250 nm, more preferably about 30 to 100 nm.

Crosslinked in the step of crosslinking a crosslinkable group A ^2, depending on the reaction mode of the crosslinkable group A ^2, to the liquid crystal alignment film precursor, heating is performed with light or electron beam irradiation, a crosslinking group A ² React. For example, when the crosslinkable group A ² is a heat crosslinkable group, the step of crosslinking the crosslinkable group A ² is a step of heating the liquid crystal alignment film precursor. Thereby, the liquid crystal aligning film which concerns on this embodiment is obtained.

When the crosslinkable group A ² is subjected to a crosslinking reaction by heating, the heating temperature is not particularly limited as long as it is sufficient for the crosslinking to proceed, but is preferably about 100 to 250 ° C, and about 120 to 230 ° C. It is more preferable. The heating time is preferably 1 to 120 minutes, and more preferably 5 to 30 minutes.

  The liquid crystal alignment film according to this embodiment can be used for, for example, a liquid crystal cell, a liquid crystal display element, an optical anisotropic film, an optical device, and the like. In addition, the liquid crystal alignment film according to the present embodiment can be used for manufacturing an optical anisotropic body.

(Liquid crystal cell, liquid crystal display element and liquid crystal display)

  The liquid crystal cell according to the present embodiment has a configuration in which liquid crystal is disposed between two substrates. It is sufficient that at least one of the substrates includes the liquid crystal alignment film according to this embodiment, and both of the substrates may include the liquid crystal alignment film according to this embodiment. Moreover, the liquid crystal display element which concerns on this embodiment is provided with a liquid crystal cell provided with the liquid crystal aligning film which concerns on this embodiment, and the polarizing plate bonded together on the outer surface of the said liquid crystal cell, for example.

  Using a liquid crystal alignment film (photo-alignment film) or a liquid crystal alignment film precursor manufactured by the above method, a liquid crystal cell in which a liquid crystal composition is sandwiched between a pair of substrates and a liquid crystal display element using the same are manufactured. Can do.

As a manufacturing method of a liquid crystal cell, the following method is mentioned, for example. That is, a method for manufacturing a liquid crystal cell includes a step of preparing two substrates having a front surface of a liquid crystal alignment film on the surface, a step of applying a sealant to a peripheral portion on at least one liquid crystal alignment film of the substrate, A process of bonding two substrates so that the liquid crystal alignment film faces each other with a certain gap (cell gap) between them, and injecting liquid crystal into the cell gap defined by the liquid crystal alignment film and the sealant Then, a step of sealing the injection hole to obtain a liquid crystal cell is provided. In the manufacturing method, both of the two substrates include the liquid crystal alignment film manufactured by the above method, but one of the two substrates may include the liquid crystal alignment film. Further, a liquid crystal alignment film precursor may be used instead of the liquid crystal alignment film. In this case, a method of manufacturing a liquid crystal cell comprises a step of crosslinking a crosslinkable group A ^2. When the crosslinkable group A ² is a thermally crosslinkable group may a crosslinkable group A ² is a cross-linking reaction in the step of pressing heated substrate to be described later.

  As the sealing agent, for example, an epoxy resin can be used.

  In order to keep the cell gap constant, beads such as silica gel, alumina, and acrylic resin can be used between the substrates prior to bonding the two substrates. These beads may be used by being dispersed on the coating film of the liquid crystal alignment film, or may be used by mixing with a sealant.

The step of bonding the two substrates so that the liquid crystal alignment films face each other may be a step of pressing and heating the substrates after bonding the two substrates. Temperature of the pressing heating, type of sealant can be set as appropriate in accordance with the cross-linking temperature of the crosslinkable group A ^2, for example, it may be 100 to 200 ° C.. The time for pressing and heating may be, for example, 10 to 300 minutes.

  As the liquid crystal filled in the cell, for example, a nematic liquid crystal can be used.

  In the case of a vertical alignment type liquid crystal cell, a liquid crystal having negative dielectric anisotropy is preferable. Examples of such liquid crystal include dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, naphthalene liquid crystal, biphenyl liquid crystal, and phenylcyclohexane liquid crystal. These liquid crystals can be used alone or in combination of two or more. Usually, two or more types are used in combination according to the required performance.

  In the case of a horizontal alignment type liquid crystal cell, a liquid crystal having positive dielectric anisotropy is preferable. Examples of such liquid crystals include cyanobenzene liquid crystals, difluorobenzene liquid crystals, trifluorobenzene liquid crystals, trifluoromethylbenzene liquid crystals, trifluoromethoxybenzene liquid crystals, pyrimidine liquid crystals, naphthalene liquid crystals, and biphenyl liquid crystals. And phenylcyclohexane-based liquid crystal. These liquid crystals can be used alone or in combination of two or more. Usually, two or more types are used in combination according to the required performance.

  The liquid crystal cell can also be manufactured by a technique called an ODF (One Drop Fill) method. First, for example, an ultraviolet light curable sealant is applied to a predetermined place on the substrate on which the liquid crystal alignment film is formed, and the liquid crystal is dropped in a region surrounded by the sealant on the liquid crystal alignment film. Thereafter, another substrate is bonded so that the liquid crystal alignment films face each other. Next, the liquid crystal cell can be manufactured by irradiating the entire surface of the substrate with ultraviolet light and curing the sealant.

  In any case of producing the liquid crystal cell by any method, it is desirable to remove the flow alignment at the time of injection by heating to a temperature at which the liquid crystal used has an isotropic phase and then gradually cooling to room temperature. In the slow cooling process, the liquid crystal is realigned due to the influence of the alignment regulating force of the liquid crystal alignment film.

  A liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell thus manufactured.

  Examples of the polarizing plate include a polarizing plate made of “H film” in which iodine is absorbed while polyvinyl alcohol is stretched and oriented, or a polarizing plate in which the H film is sandwiched between cellulose acetate protective films.

  The liquid crystal display element including the liquid crystal alignment film according to the present embodiment has excellent reliability against AC image sticking because the liquid crystal alignment film includes the cured product of the polymer according to the present embodiment. In addition, since the liquid crystal alignment film according to the present embodiment is used, any one of a horizontal alignment type liquid crystal display element and a vertical alignment type liquid crystal display element can be manufactured.

  The liquid crystal display element according to this embodiment can be used for a liquid crystal display or the like. That is, according to this embodiment, a liquid crystal display including the liquid crystal display element according to this embodiment is obtained.

(Optical anisotropic body, optical anisotropic film and optical device)
Polymerization is performed in a state where a polymerizable liquid crystal composition is applied on the liquid crystal alignment film (photo-alignment film) according to the present embodiment, and the polymerizable liquid crystal molecules (polymerizable liquid crystal molecules) in the polymerizable liquid crystal composition are aligned. By making it, an optical anisotropic body can also be manufactured. The optically anisotropic body means a substance having a difference in optical properties such as a light propagation speed, a refractive index, and absorption depending on a traveling direction when light travels in the substance.

  The polymerizable liquid crystal composition is a composition containing a polymerizable liquid crystal, and is a single or a mixture with another liquid crystal compound and exhibits liquid crystallinity. Examples of the polymerizable liquid crystal composition include, for example, Handbook of Liquid Crystals (D. Demus, JW Goodby, GW Gray, H. W. Spiss, V. Vill, edited by Wiley-VCH, 1998. ), Quarterly Chemical Review No. 22, Liquid Crystal Chemistry (Edited by Chemical Society of Japan, 1994), or JP-A-7-294735, JP-A-8-3111, JP-A-8-29618, JP-A-11-80090, 1,4-phenylene group, 1,4-cyclohexene, as described in Kaihei 11-148079, JP-A 2000-178233, JP-A 2002-308831, and JP-A 2002-145830. A rod-like polymerizable liquid crystal compound having a rigid site called a mesogen in which a plurality of structures such as a silene group are connected, and a polymerizable functional group such as a (meth) acryloyloxy group, a vinyloxy group, and an epoxy group, or JP-A-2004-2373 And a rod-like polymerizable liquid crystal compound having a maleimide group as described in JP-A-2004-99446 Alternatively, a rod-like polycyclic liquid crystal compound having an allyl ether group as described in JP-A No. 2004-149522, or, for example, Handbook of Liquid Crystals (D. Demus, JW Goodbye, GW Gray, H. W. Spiess, V. Vill, published by Wiley-VCH, 1998), Quarterly Chemical Review No. 22. Liquid crystal chemistry (edited by Chemical Society of Japan, 1994) and discotic polymerizable compounds described in JP-A-07-146409. Among these, a rod-like liquid crystal compound having a polymerizable group is preferable because it can easily produce a liquid crystal having a temperature range around room temperature.

  The optical anisotropic body obtained as described above is useful for applications such as an optical anisotropic film used for optical compensation of a liquid crystal display element. The optically anisotropic film may be composed only of an optical anisotropic body, and may include the optical anisotropic body and the liquid crystal alignment film according to the present embodiment. The optically anisotropic film may be a retardation plate, for example. The retardation plate is used in an optical device such as a liquid crystal display or a digital camera.

  Hereinafter, although an example is given and the present invention is explained still in full detail, the present invention is not limited by these. The structure of the compound was confirmed by mass spectrum (MS), nuclear magnetic resonance spectrum (NMR) and the like. Unless otherwise specified, “part” and “%” are based on mass.

<Synthesis of monomer>
[Synthesis Example 1: Synthesis of monomer (a-1)]
Monomer (a-1) was synthesized by the method shown in the following formula.

  Specifically, first, 10-bromo-1-decanol, methacrylic acid, p-toluenesulfonic acid monohydrate, cyclohexane and diisopropyl ether were added to a reaction vessel equipped with a thermometer, a stirring device and a Dean-Stark device. And reacted to obtain compound (a-1-1).

  Subsequently, p-hydroxybenzaldehyde, potassium carbonate and the compound (a-1-1) were suspended in DMF in the reaction vessel and stirred at 90 ° C. for 6 hours, and then the reaction was terminated. The solution after completion of the reaction was cooled to 10 ° C., and then water was added dropwise to the solution to precipitate a solid. The precipitated solid was collected by filtration to obtain a compound (a-1-2) as a brown granular solid.

  Next, in a reaction vessel, compound (a-1-2) is dissolved in methanol, and sodium dihydrogen phosphate aqueous solution (solution in which sodium dihydrogen phosphate dihydrate is dissolved in water) and 30% Hydrogen peroxide water was added sequentially. Then, an aqueous sodium chlorite solution was added dropwise. The solution after completion of the dropwise addition was reacted by stirring at 45 ° C. for 3 hours, and then the reaction was terminated. After the reaction was completed, the solution was slowly cooled to 20 ° C., and water was added dropwise to the solution to precipitate a solid. The precipitated solid was collected by filtration, and the solid was washed by sprinkling with water. The crude product of colorless scaly crystals thus obtained was dried under reduced pressure for 8 hours to obtain a compound (a-1-3) as colorless crystals.

  On the other hand, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride and 4-dimethylaminopyridine were added to a reaction vessel equipped with a thermometer and a stirrer and dissolved in 2-cyanoethanol. A solution prepared by dissolving ferulic acid in 2-cyanoethanol was added dropwise to this solution at 10 ° C. over 1 hour, followed by stirring at room temperature for 4 hours. Subsequently, this reaction solution and 15 ° C. cold water were mixed to form a mixed solution, and a toluene / THF mixed solvent was added to the obtained mixed solution, followed by liquid separation to extract an organic layer. The obtained organic layer was washed with saturated brine and then concentrated to obtain a yellow solid. The obtained yellow solid was recrystallized to obtain a white solid compound (a-1-4).

  Next, the compound (a-1-3), the compound (a-1-4) and 4-dimethylaminopyridine were added to a reaction vessel equipped with a thermometer and a stirrer, and suspended in dichloromethane. Subsequently, diisopropylcarbodiimide was dropped while maintaining the internal temperature of the reaction vessel at 10 ° C. or lower, and the mixture was stirred at 15 to 25 ° C. for 3 hours. After confirming disappearance of the raw materials (compound (a-1-3) and compound (a-1-4)), the reaction was deactivated by adding water to the reaction solution to obtain a precipitate. The resulting precipitate was filtered off, and the precipitate was dissolved in dichloromethane to form a dichloromethane solution, and then purified by column chromatography. Dichloromethane was distilled off from the purified dichloromethane solution under reduced pressure, methanol was added, and the mixture was cooled to 0 ° C. to precipitate crystals. Crystals were separated by filtration and dried under reduced pressure to obtain a monomer (a-1) having a photoreactive group capable of photodimerization.

[Synthesis Example 2: Synthesis of monomer (a-2)]
Monomer (a-2) was synthesized by the method shown in the following formula.

  Specifically, first, 6-chloro-1-hexanol, acrylic acid, and p-toluenesulfonic acid monohydrate were added to a reaction vessel equipped with a thermometer, a stirring device, and a Dean-Stark device, and reacted. (A-2-1) was obtained.

  On the other hand, aniline was added to a reaction vessel equipped with a thermometer and a stirring device and suspended in an aqueous hydrochloric acid solution. Next, sodium nitrite was added and reacted while cooling with ice, and then phenol and sodium hydroxide were added and reacted to obtain compound (a-2-2).

  Next, the compound (a-2-2) and potassium carbonate were added to a reaction vessel equipped with a thermometer and a stirring device, and reacted with the compound (a-2-1). This obtained the monomer (a-2) which has a photoreactive group which can be photoisomerized.

[Synthesis Example 3: Synthesis of monomer (a-3)]
According to the method described in Example 1 of JP2013-33248A, the monomer (a-3) was synthesized by the method shown in the following formula.

  Specifically, first, ferulic acid was dissolved in methanol, and sulfuric acid was added to the resulting solution at room temperature. Then, after raising the temperature until the solvent was refluxed, the reaction was carried out for 2 hours under reflux. After cooling the reaction solution, ice and water were added. The supernatant was removed by decantation and further crystallized by adding water at 5 ° C. The obtained white crystals were collected by filtration, washed with 1M aqueous sodium hydrogen carbonate solution and water, and then vacuum dried to obtain compound (a-3-1).

  Next, the compound (a-3-1) was dissolved in dimethylacetamide. To the resulting solution was added potassium carbonate and potassium iodide. 8-Chlorooctanol was added dropwise to the obtained dispersion and stirred at room temperature for 1 hour. Furthermore, after stirring at 70 degreeC for 8 hours, the reaction liquid was filtered and the insoluble matter was removed. Methyl isobutyl ketone and water were added to the filtrate and stirred, and then allowed to stand and separated to extract an organic layer. A series of water washing operations of adding water to the extracted organic layer, stirring, allowing to stand, and liquid separation were repeated twice. Subsequently, the solvent was removed from the obtained organic layer by vacuum distillation using an evaporator to obtain a crude product of the compound (a-3-2).

  The whole amount of the crude product of compound (a-3-2) was dissolved in ethanol. Water and sodium hydroxide were added to the resulting solution and stirred at 80 ° C. for 1 hour. After cooling the reaction solution to about 3 ° C., a 2M hydrochloric acid aqueous solution was added while maintaining the temperature at 5 ° C. or less to adjust the pH to 2. The precipitated white precipitate was collected by filtration, washed twice with a mixed solution of water and methanol, and dried under vacuum to obtain compound (a-3-3).

  Next, the compound (a-3-3) was dissolved in chloroform. BHT (di-t-butyl-hydroxytoluene) and triethylamine were added to the resulting solution as a polymerization inhibitor, and the mixture was stirred under ice cooling. Methacrylic acid chloride was added dropwise to the reaction solution, and the mixture was stirred at 5 ° C. or lower for 5 hours. Dimethylaminopyridine and water were added to the resulting reaction solution, and the mixture was stirred at room temperature for 12 hours, then allowed to stand and separated to extract an organic layer. A series of washing operations of adding a 2N hydrochloric acid aqueous solution to the extracted organic layer, stirring, allowing to stand, and separating the solution was repeated twice. Next, n-heptane was added to the obtained organic layer, and the precipitated crystals were collected by filtration. The obtained crystal was washed twice with a mixed solvent consisting of water and methanol, and vacuum-dried to obtain a monomer (a-3).

[Synthesis Example 4: Synthesis of monomer (c-1)]
Monomer (c-1) was synthesized by the method shown in the following formula.

  Specifically, first, p-hydroxybenzaldehyde, potassium carbonate and a compound (a-2-1) are added to a reaction vessel equipped with a thermometer and a stirring device, suspended in DMF, and at 90 ° C. for 6 hours. After reacting with stirring, the reaction was terminated. The solution after completion of the reaction was cooled to 10 ° C., and then water was added dropwise to the solution to precipitate a solid. The precipitated solid was collected by filtration to obtain compound (c-1-1).

  Next, in a reaction vessel, the compound (c-1-1) was dissolved in methanol, and an aqueous sodium dihydrogen phosphate solution and 30% hydrogen peroxide solution were sequentially added thereto. Then, an aqueous sodium chlorite solution was added dropwise. The solution after completion of the dropwise addition was reacted by stirring at 45 ° C. for 3 hours, and then the reaction was terminated. After the reaction was completed, the solution was slowly cooled to 20 ° C., and water was added dropwise to the solution to precipitate a solid. The precipitated solid was collected by filtration, and the solid was washed by sprinkling with water. The crude product thus obtained was dried under reduced pressure for 8 hours to obtain a monomer (c-1) having a thermal crosslinking promoting group.

<Preparation of liquid crystal composition>

A nematic liquid crystal composition (liquid crystal composition 1) was prepared by blending the liquid crystal compounds shown in Table 1 in the blending amounts shown in the same table. As a result of thermal analysis on the obtained liquid crystal composition 1, the nematic-isotropic liquid phase transition temperature (clearing point) was 85.6 ° C. The extraordinary refractive index ne at a wavelength of 589 nm was 1.596, and the ordinary refractive index no at a wavelength of 589 nm was 1.491. The dielectric anisotropy was +7.0, and K22 (twist elastic modulus) was 7.4 pN.

Example 1
<Synthesis of polymer for liquid crystal alignment film>
After adding 4.91 g of monomer (a-1) obtained in Synthesis Example 1, 93.2 mg of N- (hydroxymethyl) acrylamide and 30.3 mg of azobisisobutyronitrile (AIBN) to a clean flask The inside of the flask was purged with nitrogen. Next, these were dissolved in 24.9 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. The flask was then heated to 55 ° C. and stirred under a nitrogen atmosphere to initiate the reaction. After reacting for 7 hours, 5 times the amount of monomer used (5 mL with respect to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane and decantation was further performed three times, and then the obtained reaction mixture was reduced in pressure at 20 ° C. and 0.13 kPa for 24 hours. Dried. Thereby, 1.5g of polymers (P-1) for liquid crystal aligning films which have a structural unit (u-1) and a structural unit (u-5) represented by a following formula were obtained. The weight average molecular weight of the polymer for liquid crystal alignment films (P-1) was 198,000. The proportion of the structural unit (u-1) in the total of the structural unit (u-1) and the structural unit (u-5) is 90 mol%, and the proportion of the structural unit (u-5) is 10 mol%. there were. The “monomer amount” means the total amount of the monomer (a-1) and N- (hydroxymethyl) acrylamide.

  The weight average molecular weight is a standard polystyrene equivalent value measured by gel permeation chromatography. Further, the ratio of each structural unit was calculated from the amount of raw material input at the time of synthesis. The same applies to other examples and comparative examples.

<Manufacture of liquid crystal cells>
After the polymer for liquid crystal alignment film (P-1) was dissolved in N-methyl-2-pyrrolidone (NMP), 2-butoxyethanol was added to the resulting solution, and the mass ratio was NMP: 2-butoxyethanol: P1 = It adjusted so that it might become 47.5: 47.5: 5, it filtered using MS PTFE syringe filter (pore diameter: 5um, 1um, and 0.45um) made by menbrane solution, and the polymer for liquid crystal alignment films (photo-alignment film) Polymer) solution. Spin coater (trade name) manufactured by Mikasa Co., Ltd. so that the thickness of this solution is about 90 nm on an IPS3035-2up substrate manufactured by FPD Solution and a counter substrate (substrate coated with ITO on one side). : IH-DX-2) was applied by spin coating. Application to the counter substrate was performed on the surface not coated with ITO. Then, it is dried for 3 minutes at 80 ° C. on a hot plate (trade name: digital hot plate NINOS ND1) manufactured by AS ONE Co., Ltd., and further, using an oven (trade name: DO-600FA) manufactured by AS ONE Co., Ltd. Then, it was dried at 150 ° C. for 5 minutes in an air atmosphere. After drying, it was gradually cooled to room temperature. Then, by using the polarization illumination apparatus Co. Mejiro Ltd. Precision, linearly polarized light having a wavelength of 313nm to the dried film was irradiated 7.5 seconds at an intensity of 20 mW / cm ² (integral illuminance: 150mJ / ^cm 2). This obtained the liquid crystal aligning film precursor on the IPS3035-2up board | substrate and the opposing board | substrate.

  Subsequently, among the substrates on which the liquid crystal alignment film precursor is formed, a seal dispenser (trade name: shot-mini) manufactured by Musashi Engineering Co., Ltd. is used on the periphery of the liquid crystal alignment film precursor of the IPS3035-2up substrate. A sealing agent (trade name: struct bond XN-21-S, “Struct Bond” is a registered trademark) manufactured by Mitsui Chemicals, Inc. was applied. Next, after the sealing agent is dried at 90 ° C. for 30 minutes, the surface on the sealing agent side of the IPS3035-2up substrate and the surface on the liquid crystal alignment film precursor side of the counter substrate are opposed to each other with a certain gap (3.5 μm ) Was maintained, and both substrates were bonded together. After pasting both substrates together, pressure heating was performed at 150 ° C. for 90 minutes to produce a glass cell. After cooling to room temperature, the liquid crystal composition 1 was vacuum injected into the produced cell. Vacuum injection of the liquid crystal was performed using a vacuum injection device manufactured by Mikasa Corporation. After the liquid crystal was injected, a sealing material (trade name: 3026B) manufactured by 3M was applied to the cell opening. Subsequently, using a UV irradiation apparatus manufactured by Fujiwara Seisakusho, the ultraviolet light was irradiated only in the vicinity of the sealing material to seal it. A conducting wire was attached to the glass cell after sealing and heated at 92 ° C. for 2 minutes. This obtained the liquid crystal cell provided with a liquid crystal aligning film (photo-alignment film).

(Example 2)
In a clean flask, 3.84 g of monomer (a-1) obtained in Synthesis Example 1, 285.9 mg of monomer (c-1) obtained in Synthesis Example 4, and N- (methoxymethyl) methacrylamide 68 After adding 4 mg and azobisisobutyronitrile (AIBN) 24.7 mg, the atmosphere in the flask was replaced with nitrogen. Next, these were dissolved in 14.3 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Subsequently, it heated so that the inside of a flask might be 60 degreeC, it stirred under nitrogen atmosphere, and reaction was started. After reacting for 1.5 hours, 5 times the amount of monomer used (5 mL with respect to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane, and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. This obtained 1.5g of polymers (P-2) for liquid crystal aligning films which have the structural unit (u-1), the structural unit (u-4), and the structural unit (u-6) which are represented by a following formula. . The weight average molecular weight of the polymer (P-2) for liquid crystal aligning films was 210000. The ratio of the structural unit (u-1) to the total of the structural unit (u-1), the structural unit (u-4), and the structural unit (u-6) is 90 mol%, and the structural unit (u-4) ) Was 5 mol%, and the proportion of structural units (u-6) was 5 mol%. The “monomer amount” means the total amount of monomer (a-1), monomer (c-1) and N- (methoxymethyl) methacrylamide.

  Next, a liquid crystal alignment film (photo-alignment film) was obtained in the same manner as in Example 1 except that the liquid crystal alignment film polymer (P-2) was used instead of the liquid crystal alignment film polymer (P-1). A liquid crystal cell having was obtained.

Example 3
In a clean flask, 2.29 g of the monomer (a-1) obtained in Synthesis Example 1, 150.0 mg of the monomer (a-2) obtained in Synthesis Example 2, and N- (methoxymethyl) methacrylamide 36 0.7 mg, 18.5 mg of methacrylic acid, and 29.2 mg of azobisisobutyronitrile (AIBN) were added, and the atmosphere in the flask was replaced with nitrogen. Next, these were dissolved in 6.6 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Subsequently, it heated so that the inside of a flask might be 60 degreeC, it stirred under nitrogen atmosphere, and reaction was started. After reacting for 2 hours, 5 times the amount of monomer used (5 mL relative to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane, and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. Thereby, the polymer for liquid crystal alignment film (P-) having the structural unit (u-1), the structural unit (u-2), the structural unit (u-6), and the structural unit (u-7) represented by the following formula: 1.5 g of 3) was obtained. The weight average molecular weight of the polymer for liquid crystal alignment films (P-3) was 201,000. The proportion of the structural unit (u-1) in the total of the structural unit (u-1), the structural unit (u-2), the structural unit (u-6), and the structural unit (u-7) is 85 mol%. The proportion of the structural unit (u-2) is 5 mol%, the proportion of the structural unit (u-6) is 5 mol%, and the proportion of the structural unit (u-7) is 5 mol%. It was. The “monomer amount” means the total amount of monomer (a-1), monomer (a-2), N- (methoxymethyl) methacrylamide and methacrylic acid.

  Next, a liquid crystal alignment film (photo-alignment film) was obtained in the same manner as in Example 1 except that the liquid crystal alignment film polymer (P-3) was used instead of the liquid crystal alignment film polymer (P-1). A liquid crystal cell having was obtained.

(Example 4)
In a clean flask, 2.26 g of the monomer (a-1) obtained in Synthesis Example 1, 147.9 mg of the monomer (a-2) obtained in Synthesis Example 2, and N- (methoxymethyl) methacrylamide 36 After adding 1 mg, 54.6 mg of the monomer (a-3) obtained in Synthesis Example 3 and 28.8 mg of azobisisobutyronitrile (AIBN), the atmosphere in the flask was replaced with nitrogen. Next, these were dissolved in 6.6 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Subsequently, it heated so that the inside of a flask might be 60 degreeC, it stirred under nitrogen atmosphere, and reaction was started. After reacting for 2 hours, 5 times the amount of monomer used (5 mL relative to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane, and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. Thereby, the polymer for liquid crystal alignment film (P-) having the structural unit (u-1), the structural unit (u-2), the structural unit (u-3) and the structural unit (u-6) represented by the following formula: 4 g of 4) was obtained. The weight average molecular weight of the polymer (P-4) for liquid crystal aligning films was 185000. The proportion of the structural unit (u-1) in the total of the structural unit (u-1), the structural unit (u-2), the structural unit (u-3), and the structural unit (u-6) is 85 mol%. The proportion of the structural unit (u-2) is 5 mol%, the proportion of the structural unit (u-3) is 5 mol%, and the proportion of the structural unit (u-6) is 5 mol%. It was. The “monomer amount” refers to the total amount of monomer (a-1), monomer (a-2), monomer (a-3) and N- (methoxymethyl) methacrylamide. Means.

  Next, a liquid crystal alignment film (photo-alignment film) was obtained in the same manner as in Example 1 except that the liquid crystal alignment film polymer (P-4) was used instead of the liquid crystal alignment film polymer (P-1). A liquid crystal cell having was obtained.

(Example 5)
In a clean flask, 4.01 g of monomer (a-1) obtained in Synthesis Example 1, 285.9 mg of monomer (c-1) obtained in Synthesis Example 4, and azobisisobutyronitrile (AIBN) After 24.7 mg was added, the atmosphere in the flask was replaced with nitrogen. Next, these were dissolved in 14.3 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Subsequently, it heated so that the inside of a flask might be 60 degreeC, it stirred under nitrogen atmosphere, and reaction was started. After reacting for 1.5 hours, 5 times the amount of monomer used (5 mL with respect to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane, and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. Thereby, 1.4g of polymers (P-5) for liquid crystal aligning films which have a structural unit (u-1) and a structural unit (u-4) represented by a following formula were obtained. The weight average molecular weight of the polymer (P-5) for liquid crystal aligning films was 240000. The proportion of the structural unit (u-1) in the total of the structural unit (u-1) and the structural unit (u-4) is 90 mol%, and the proportion of the structural unit (u-4) is 10 mol%. there were. The “monomer amount” means the total amount of the monomer (a-1) and the monomer (c-1).

  Next, instead of the liquid crystal alignment film polymer (P-1), the liquid crystal alignment film polymer (P-1) and the liquid crystal alignment film polymer (P-5) were mixed at a mass ratio of 1: 1. A liquid crystal cell having a liquid crystal alignment film (photo-alignment film) was obtained in the same manner as in Example 1 except that the obtained polymer mixture (solid content) was used.

(Example 6)
In a clean flask, 4.01 g of monomer (a-1) obtained in Synthesis Example 1, monomer (b-1) represented by the following formula (trade name “Karenz MOI-BP” manufactured by Showa Denko KK) ) 285.9 mg and azobisisobutyronitrile (AIBN) 24.7 mg were added, and the atmosphere in the flask was replaced with nitrogen. Next, these were dissolved in 14.3 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Subsequently, it heated so that the inside of a flask might be 60 degreeC, it stirred under nitrogen atmosphere, and reaction was started. After reacting for 1.5 hours, 5 times the amount of monomer used (5 mL with respect to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane, and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. As a result, 1.35 g of a liquid crystal alignment film polymer (P-6) having a structural unit (u-1) and a structural unit (u-8) represented by the following formula was obtained. The weight average molecular weight of the polymer for liquid crystal alignment films (P-6) was 260000. The proportion of the structural unit (u-1) in the total of the structural unit (u-1) and the structural unit (u-8) is 90 mol%, and the proportion of the structural unit (u-8) is 10 mol%. there were. The “monomer amount” means the total amount of the monomer (a-1) and the monomer (b-1).

  Next, a liquid crystal alignment film (photo alignment film) was obtained in the same manner as in Example 1 except that the liquid crystal alignment film polymer (P-6) was used instead of the liquid crystal alignment film polymer (P-1). A liquid crystal cell having was obtained.

(Example 7)
In a clean flask, 3.84 g of the monomer (a-1) obtained in Synthesis Example 1, 285.9 mg of the monomer (c-1) obtained in Synthesis Example 4, and the monomer (b -1) After adding 140.4 mg and 24.7 mg of azobisisobutyronitrile (AIBN), the atmosphere in the flask was replaced with nitrogen. Next, these were dissolved in 14.3 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Subsequently, it heated so that the inside of a flask might be 60 degreeC, it stirred under nitrogen atmosphere, and reaction was started. After reacting for 1.5 hours, 5 times the amount of monomer used (5 mL with respect to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane, and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. As a result, 1.5 g of a liquid crystal alignment film polymer (P-7) having a structural unit (u-1), a structural unit (u-4), and a structural unit (u-8) represented by the following formula was obtained. . The weight average molecular weight of the polymer (P-7) for liquid crystal aligning films was 200000. The ratio of the structural unit (u-1) to the total of the structural unit (u-1), the structural unit (u-4), and the structural unit (u-8) is 90 mol%, and the structural unit (u-4 ) Was 5 mol%, and the proportion of structural units (u-8) was 5 mol%. The “monomer amount” means the total amount of the monomer (a-1), the monomer (b-1) and the monomer (c-1).

  Next, a liquid crystal alignment film (photo alignment film) was obtained in the same manner as in Example 1 except that the liquid crystal alignment film polymer (P-7) was used instead of the liquid crystal alignment film polymer (P-1). A liquid crystal cell having was obtained.

(Example 8)
In a clean flask, 2.29 g of the monomer (a-1) obtained in Synthesis Example 1, 150.0 mg of the monomer (a-2) obtained in Synthesis Example 2, and the monomer (b -1) After adding 70.7 mg, 18.5 mg of methacrylic acid, and 29.2 mg of azobisisobutyronitrile (AIBN), the atmosphere in the flask was replaced with nitrogen. Next, these were dissolved in 6.6 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Subsequently, it heated so that the inside of a flask might be 60 degreeC, it stirred under nitrogen atmosphere, and reaction was started. After reacting for 2 hours, 5 times the amount of monomer used (5 mL relative to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. Thereby, the polymer for liquid crystal alignment films (P-) having the structural unit (u-1), the structural unit (u-2), the structural unit (u-7) and the structural unit (u-8) represented by the following formula: 1.53 g of 8) was obtained. The weight average molecular weight of the polymer for liquid crystal alignment films (P-8) was 221,000. The ratio of the structural unit (u-1) to the total of the structural unit (u-1), the structural unit (u-2), the structural unit (u-7), and the structural unit (u-8) is 85 mol%. The proportion of the structural unit (u-2) is 5 mol%, the proportion of the structural unit (u-7) is 5 mol%, and the proportion of the structural unit (u-8) is 5 mol%. It was. The “monomer amount” means the total amount of monomer (a-1), monomer (a-2), monomer (b-1) and methacrylic acid.

  Next, a liquid crystal alignment film (photo alignment film) was obtained in the same manner as in Example 1 except that the liquid crystal alignment film polymer (P-8) was used instead of the liquid crystal alignment film polymer (P-1). A liquid crystal cell having was obtained.

Example 9
Instead of the liquid crystal alignment film polymer (P-1), the liquid crystal alignment film polymer (P-5) and the liquid crystal alignment film polymer (P-6) were mixed at a mass ratio of 1: 1. A liquid crystal cell having a liquid crystal alignment film (photo-alignment film) was obtained in the same manner as in Example 1 except that the polymer mixture (solid content) was used.

(Comparative Example 1)
After adding 2.49 g of monomer (a-1) obtained in Synthesis Example 1 and 28.8 mg of azobisisobutyronitrile (AIBN) to a clean flask, the inside of the flask was purged with nitrogen. Next, these were dissolved in 6.6 ml of tetrahydrofuran (THF) from which dissolved oxygen was removed. Next, the inside of the flask was heated to 60 ° C. and stirred under a nitrogen atmosphere to start the reaction. After reacting for 2 hours, 5 times the amount of monomer used (5 mL relative to 1 g of monomer) was added to the resulting reaction solution to precipitate the reaction mixture. Next, after removing the supernatant by decantation, the reaction mixture was redissolved in THF of 3 times the amount of monomer used (3 mL per 1 g of monomer). Subsequently, hexane of 5 times the amount of the monomer used (5 mL relative to 1 g of monomer) was added to the obtained solution to precipitate the reaction mixture, and then the supernatant was removed by decantation. The series of operations of redissolving the precipitated reaction mixture in THF, precipitation with hexane, and decantation was further performed three times, and then the obtained reaction mixture was protected from light at 20 ° C. and 0.13 kPa for 24 hours. Dry under reduced pressure. As a result, 1.43 g of a polymer for liquid crystal alignment film (Ref-1) having a structural unit (u-1) represented by the following formula was obtained. The weight average molecular weight of the polymer for liquid crystal alignment films (Ref-1) was 250,000.

  Next, a liquid crystal alignment film (photo-alignment film) was obtained in the same manner as in Example 1 except that the liquid crystal alignment film polymer (Ref-1) was used instead of the liquid crystal alignment film polymer (P-1). A liquid crystal cell having was obtained.

(Evaluation)
About the liquid crystal cell of an Example and a comparative example, the reliability with respect to AC image sticking was evaluated by the following method. This will be described with reference to FIG. FIG. 2 is a schematic diagram showing a VT curve on the electrode of the liquid crystal cell, and does not show the VT curves of Examples and Comparative Examples.

  First, using a LCD 5200 (trade name) manufactured by Otsuka Electronics Co., Ltd., the transmittance at each voltage was measured while changing the applied voltage (AC voltage), thereby obtaining a VT curve on the electrode of the liquid crystal cell ( A) in FIG. From the obtained VT curve, the light transmittance T1 on each electrode at 4 V before stress application was determined.

  Thereafter, stress (AC voltage) having a frequency of 60 Hz and a voltage of 10 V was applied to the electrodes in a thermostat at 60 ° C. (manufactured by ESPEC Co., Ltd.) for 64 hours. After applying the stress, a VT curve was obtained again using the LCD 5200 (B in FIG. 2). From the obtained VT curve, the light transmittance T2 on each electrode at 4 V after stress application was determined, and the ratio of light transmittance before and after stress application (T2 / T1) was calculated. This ratio (T2 / T1) was used as an evaluation parameter indicating the degree of initial image sticking. In an ideal state where there is no AC image sticking, (T2 / T1) becomes 1, and (T2 / T1) becomes larger than 1 when the ideal state is separated.

  Thereafter, a stress (AC voltage) having a frequency of 60 Hz and a voltage of 10 V was applied to the electrode in the thermostat at 60 ° C. for 186 hours. That is, stress (AC voltage) having a frequency of 60 Hz and a voltage of 10 V was applied to the electrodes at 60 ° C. for a total of 250 hours. After applying the stress, a VT curve was obtained again using the LCD 5200 (C in FIG. 2). From the obtained VT curve, the light transmittance T3 on each electrode at 4 V after the stress application was obtained, and the ratio of light transmittance before and after the stress application (T3 / T1) was calculated. This ratio (T3 / T1) was used as an evaluation parameter indicating the degree of image sticking after a long period of time. In an ideal state where there is no AC image sticking, (T3 / T1) is 1, and when away from the ideal state, (T3 / T1) is greater than 1.

  The difference (T3 / T1-T2 / T1) between (T2 / T1) and (T3 / T1) was defined as AC burn-in reliability, and the reliability against AC burn-in was evaluated. It is evaluated that the smaller the difference (T3 / T1-T2 / T1), the higher the reliability of the liquid crystal alignment film (photo-alignment film) against AC image sticking.

Claims (19)

The polymer for liquid crystal aligning films containing the structural unit A represented by following formula (1), and the structural unit B represented by following formula (2).

(In formula (1), M ¹ represents any group selected from the group consisting of groups represented by the following formulas (M-1) to (M-6), and A ¹ represents photodimerization or light. In the case where the photoreactive group is isomerizable and includes a plurality of structural units A in the polymer, a plurality of M ¹ may be the same as or different from each other, and a plurality of A ¹ are the same as each other May be different.)

(In the formula (2), M ² represents any group selected from the group consisting of groups represented by the following formulas (M-1) to (M-6), and A ² represents a crosslinkable group. In the case where the polymer includes a plurality of structural units B, the plurality of M ² may be the same or different from each other, and the plurality of A ² may be the same or different from each other.

(In the formulas (M-1) to (M-6), a broken line represents a bond to A ¹ or A ² , R ¹⁰ , R ¹³ and R ¹⁴ represent a hydrogen atom or a methyl group, and R ¹¹ represents And represents a hydrogen atom, a carboxyl group or a carbamoyl group, and R ¹² represents a hydrogen atom, a methyl group or a carboxymethyl group.)   The polymer for a liquid crystal alignment film according to claim 1, wherein the crosslinkable group includes at least one group selected from the group consisting of an alkoxymethylol group, a methylol group, and a blocked isocyanate group. The polymer for a liquid crystal alignment film according to claim ¹ , wherein the structural unit A includes a structural unit in which the A ¹ is a photoreactive group capable of photodimerization. Wherein as a structural unit A, wherein A comprises ¹ structural units are photoisomerisable photoreactive groups, a liquid crystal alignment film polymer according to any one of claims 1-3. The photoreactive group capable of photodimerization is a group having an α, β-unsaturated carbonyl structure,
The optical isomerizable photoreactive group is a group having an azo _structure, a liquid crystal alignment film polymer according to any one of claims 1-4.   The polymer for a liquid crystal alignment film according to claim 5, wherein the group having an α, β-unsaturated carbonyl structure is a group having a structure derived from cinnamic acid, chalcone, coumarin, or a derivative thereof.   The proportion of the structural unit A in the total of the structural unit A and the structural unit B is 80 to 99.9 mol%, and the proportion of the structural unit B is 0.1 to 20 mol%. The polymer for liquid crystal aligning film as described in any one of 1-6. The polymer for liquid crystal aligning films as described in any one of Claims 1-6 which further contains the structural unit C represented by following formula (3).

(In Formula (3), M ³ represents any group selected from the group consisting of groups represented by Formulas (M-1) to (M-6), and A ³ represents a crosslinking accelerator group. When the polymer contains a plurality of structural units C, the plurality of M ³ may be the same or different from each other, and the plurality of A ³ may be the same or different from each other. The polymer for a liquid crystal alignment film according to claim 8, wherein each of M ¹ , M ² and M ³ independently represents a group represented by the following formula (M-7) or (M-8).

(In the formulas (M-7) and (M-8), a broken line represents a bond to A ¹ , A ² or A ³ , and R ¹⁵ and R ¹⁶ represent a hydrogen atom or a methyl group.)   The proportion of the structural unit A in the total of the structural unit A, the structural unit B, and the structural unit C is 80 to 99.8 mol%, and the proportion of the structural unit B is 0.1 to 10 mol%. The polymer for liquid crystal alignment film according to claim 8 or 9, wherein the proportion of the structural unit C is 0.1 to 10 mol%. The polymer for a liquid crystal alignment film according to claim ¹ , wherein the structural unit A includes a structural unit in which the A ¹ is substituted with a crosslinking accelerating group A ³ . The proportion of the structural unit A in the total of the structural unit A, the structural unit B, and the structural unit C represented by the following formula (3) is 80 to 99.9 mol%, and the proportion of the structural unit B There is a 0.1 to 10 mol%, the sum of proportions and rate of the structural units C of the structural unit a, wherein ^{a 1} is substituted with a crosslinking accelerator group is 0.1 to 90 mol%, claim 11. The polymer for liquid crystal alignment film according to 11.

(In Formula (3), M ³ represents any group selected from the group consisting of groups represented by Formulas (M-1) to (M-6), and A ³ represents a crosslinking accelerator group. When the polymer contains a plurality of structural units C, the plurality of M ³ may be the same or different from each other, and the plurality of A ³ may be the same or different from each other. Having a crosslinking accelerator group A ³ is a carboxyl group, a liquid crystal alignment film polymer according to any one of claims 8-12.   The liquid crystal aligning film containing the hardened | cured material of the polymer for liquid crystal aligning films as described in any one of Claims 1-13.   A liquid crystal display element provided with the liquid crystal aligning film of Claim 14.   A liquid crystal display comprising the liquid crystal display element according to claim 15.   15. An optical anisotropic body composed of a polymer of a polymerizable liquid crystal composition, wherein the polymerizable liquid crystal molecules in the polymerizable liquid crystal composition are aligned using the liquid crystal alignment film according to claim 14. An optical anisotropic body.   An optically anisotropic film comprising the liquid crystal alignment film according to claim 14.   An optical device comprising a retardation plate having the liquid crystal alignment film according to claim 14.

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