KR101184319B1 - Alignment agent and liquid crystalline polyimide used therein - Google Patents

Abstract

[Problem] An alignment film having good orientation, high sensitivity, and high stability is provided.
[Solution] A composition containing a polyamic acid and at least one polymer selected from polyimide obtained by the dehydration reaction of the polyamic acid, wherein the proportion of the polymer is based on the total amount of the film forming component included in the composition. It is 50-100 weight%, and the aligning agent which can form the film which has a liquid crystal temperature range between 100 degreeC and 300 degreeC by forming this composition into a film.

Description

ALIGNMENT AGENT AND LIQUID CRYSTALLINE POLYIMIDE USED THEREIN}

This invention relates to the aligning agent mainly used for manufacture of a liquid crystal display element.

Liquid crystal display elements are used in various liquid crystal display devices such as monitors of notebook PCs and desktop PCs, viewfinders of projection cameras, projection displays, and the like, and have recently been used in televisions. It is also used for optoelectronics related elements, such as an optical printer head, an optical Fourier conversion element, and a light bulb. As a conventional liquid crystal display element, a display element using a nematic liquid crystal is the mainstream, and TN (Twisted Nematic) in which the alignment direction of the liquid crystal in the vicinity of one substrate and the alignment direction of the liquid crystal in the vicinity of the other substrate are twisted at an angle of 90 degrees. ) And liquid crystal display devices such as STN (Super Twisted Nematic) mode in which the orientation direction is usually twisted at an angle of 180 degrees or more. And the liquid crystal display element of what is called TFT (thin-film-transistor) mode using a thin film transistor is also put into practical use.

However, these liquid crystal display elements have a narrow viewing angle at which an image can be appropriately viewed, and when viewed from an inclined direction, the luminance and contrast may be lowered, and the brightness inversion may be suppressed at halftone. I may cause it. In recent years, the problem of this viewing angle is the TN type liquid crystal display element using an optical compensation film, MVA (Multi-domain Vertical Alignment) mode which combined the technique of a vertical alignment and a projection structure (for example, refer patent document 1), Or it is improved by the IPS (In-Plane Switching) mode (for example, refer patent document 2) of a transverse electric field system.

The development of the technology of a liquid crystal display element is achieved not only by the improvement of these drive systems and an element structure but also the improvement of the structural member used for a display element. Among the constituent members used for the display elements, in particular, the liquid crystal aligning film is one of important factors related to the display quality of the liquid crystal display element, and the role of the liquid crystal aligning film becomes important every year as the display element becomes higher in quality.

In such a liquid crystal alignment film, it is necessary to uniformly control the molecular arrangement of the liquid crystal for uniform display characteristics of the liquid crystal display element, and thus to uniformly orient the liquid crystal molecules on the substrate in one direction, and also to provide a constant inclination angle ( Expression of the pretilt angle). Thus, the liquid crystal aligning film which aligns the direction of the liquid crystal molecule on a board | substrate similarly is an important and indispensable technique in the manufacturing process of a liquid crystal display element.

A liquid crystal aligning film is manufactured from a liquid crystal aligning agent. The liquid crystal aligning agent currently mainly used is the solution which melt | dissolved the polyamic acid or soluble polyimide in the organic solvent. After apply | coating such a solution to a board | substrate, it forms into a film by means, such as a heating, and forms a polyimide-type liquid crystal aligning film. Various liquid crystal aligning agents other than polyamic acid are also examined, but they are hardly put into practical use in terms of heat resistance, chemical resistance (liquid crystal resistance), coating properties, liquid crystal alignment, electrical characteristics, optical characteristics, display characteristics, and the like.

Industrially, the rubbing method which is simple and the high speed processing of a large area is widely used as an orientation treatment method. The rubbing method is a process of rubbing the surface of a liquid crystal aligning film to one direction using the cloth | flour which flocked fibers, such as nylon, rayon, and polyester, and by this, it becomes possible to obtain the constant orientation of a liquid crystal molecule. However, generation of dust and static electricity by the rubbing method have been pointed out as problems.

Until now, the following two are proposed as an orientation mechanism of the liquid crystal on the orientation film to which the orientation process was applied by the rubbing process.

(1) the surface shape effect of the liquid crystal aligning film resulting from the micro groove which arises by a rubbing process,

(2) Intermolecular interaction of the liquid crystal aligning film uniaxially oriented by a rubbing process, and the liquid crystal monomolecule layer which contacts this liquid crystal aligning film.

In recent years, the contribution of the surface shape effect of (1) is relatively small, and it is confirmed that the contribution of the intermolecular interaction of (2) is dominant.

In the case of such a rubbing method, in general, it is known that a large orientation regulation force (anchoring energy) with respect to a liquid crystal can be provided to a polyimide film. However, in the case of this method, the direction in which the film is rubbed by the hairs woven into the rubbing cloth is not uniform from the molecular level, and as a result, the alignment of the liquid crystals at the alignment film interface is disturbed. In addition, it is known to those skilled in the art that a black level (normally black system) is lowered when the liquid crystal display element is black (normally black) when no voltage is applied to the film. there was.

On the other hand, about the photo-alignment method which irradiates light and performs an orientation process, many orientation mechanisms, such as a photolysis method, a photoisomerization method, a photodimerization method, and a photocrosslinking method, are proposed (for example, Nonpatent literature 1, See Patent Document 3 and Patent Document 4). In particular, since the photo alignment method is a non-contact alignment method unlike the rubbing method, it is considered that only the intermolecular interaction of (2) acts as the alignment mechanism of the liquid crystal.

It is known to those skilled in the art that the photo-alignment treatment method has a higher uniformity in orientation than the rubbing method, and because it is a non-contact orientation method, no defect occurs in the film and the black level is more easily improved than the rubbing method. Moreover, the photo-alignment processing method can reduce the cause which produces a defect at the time of manufacture of a liquid crystal display element, such as dust generation and static electricity, and has many advantages. However, the anchoring energy is smaller than that of the rubbing method, and this has caused a decrease in response speed and seizure, so improvement has been required.

In order to overcome such a problem of photo-alignment, the present inventors apply | coat a liquid crystal aligning agent which consists of a polyamic acid to a board | substrate by the method of patent document 3, for example, the method of light irradiation, and then baking Found. Although the photoalignment film which has a large anchoring energy was obtained by this method, in order to obtain the liquid crystal aligning film which has sufficient anchoring energy, since light irradiation energy had to be enlarged, further improvement was needed.

[Patent Document 1] Japanese Patent No. 2947350 [Patent Document 2] Japanese Patent No. 2940354 [Patent Document 3] Japanese Patent Application Publication No. 2005-275364 [Patent Document 4] Japanese Patent Application Publication No. 11-15001

Liquid Crystal, Vol. 3, No. 4, p. 262, 1999

An object of the present invention is to provide an alignment film for rubbing with high uniformity of orientation. In addition, the present invention provides a photoalignment film having good sensitivity and high stability.

As a result of intensive research and development, the present inventors have found that the polyimide material having liquid crystallinity and high heat resistance gives anisotropy by rubbing or light, and then heats to the liquid crystal temperature of the polyimide to increase the orientation. The present invention was completed. The essence of this invention is to use liquid crystalline polyimide as an oriented film material. The present invention is represented by the following paragraph [1].

[1] A composition containing polyamic acid and at least one polymer selected from polyimide obtained by the dehydration reaction of the polyamic acid, wherein the proportion of the polymer is 50 based on the total amount of the film-forming component included in the composition. It is -100 weight%, and the aligning agent which can form the film which has a liquid crystal temperature range between 100-300 degreeC by forming this composition into a film.

When the aligning agent of this invention is used, for example as a liquid crystal aligning agent, the alignment film for rubbing with high uniformity of orientation can be provided. Moreover, a photoalignment film with good sensitivity and high stability can be provided.

The term used by this invention is demonstrated.

The compound represented by Formula (I-1) may be described as compound (I-1). Similarly, the compound represented by another formula may be briefly described.

The term "arbitrary" used in the definition of a chemical formula means "a thing which can be selected freely not only in position but also in number." For example, the expression "any A may be substituted with B, C, D, or E" means that one A may be substituted with B, C, D, or E, and a plurality of A's In addition to being substituted with any of B, C, D and E, at least two of A substituted with B, A substituted with C, A substituted with D, and A substituted with E may be mixed. Also have. However, when any -CH ₂ -may be substituted by another group, it is assumed that a plurality of consecutive -CH ₂ -are not substituted by another same group.

In the chemical formula, a group of letters (for example, A) surrounded by a hexagon means a group of a ring structure (ring A), and Me means methyl.

The substituent which is not specifically bound to any one of the carbons constituting the ring means that the bonding position is free within a chemically problematic range.

When the same symbol is used in a plurality of formulas, it means that the ring, linking group or terminal group represented by the symbol has the same definition range, but means that the same group in the definition range must be the same in all the expressions at the same time. It is not. In such a case, the same group may be selected in a plurality of formulas, and different groups may be selected for each formula.

The invention consists of the above-mentioned [1] and the following [2] to [22].

[2] The alignment agent according to [1], wherein the polyamic acid is a polyamic acid having a photosensitive group in the main chain.

[3] The alignment agent according to [2], wherein the photosensitive group is at least one of the groups represented by formulas (I) to (VI):

Here, R ¹ , R ² and R ³ are independently aromatic divalent groups.

[4] The polyamic acid having a photosensitive group in the main chain thereof is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), and formula (IV). At least one of diamines having a photosensitive group represented by -1) to formula (IV-3), formula (V-1) and formula (VI-1) to formula (VI-7), formula (A-1), Formula (A-2), Formula (A-12), Formula (A-14), Formula (A-18), Formula (A-20), Formula (A-21), Formula (A-37), Formula (VII-4), The polyamic acid obtained by reacting with at least one of the tetracarboxylic dianhydride represented by Formula (VII-5), Formula (VIII-7), and Formula (VIII-8), as described in the item [2]. Alignment agent:

Wherein R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— Alkylene having 6 to 20 carbon atoms.

[5] The polyamic acid having a photosensitive group in the main chain has at least one of tetracarboxylic dianhydrides having a photosensitive group represented by formulas (IV-4) and (VI-8), wherein formulas (VII-1) to (VII) The alignment agent as described in [2] which is a polyamic acid obtained by making it react with at least one of -3) and the diamine represented by Formula (VIII-1)-formula (VIII-6):

R ⁴ is alkylene having 6 to 20 carbon atoms; R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene.

[6] The polyamic acid having a photosensitive group in the main chain thereof is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3) and formula (III-) as described in [4]. 1), at least one of the diamines having a photosensitive group represented by formulas (IV-1) to (IV-3), formulas (V-1) and (VI-1) to (VI-7) and a formula ( A mixture with at least one of the diamines represented by VII-1) to formula (VII-3) and formula (VIII-1) to formula (VIII-6) is formula (A-1) as described in item [4], Formula (A-2), Formula (A-12), Formula (A-14), Formula (A-18), Formula (A-20), Formula (A-21), Formula (A-37), Formula (VII-4), The polyamic acid obtained by reacting with at least one of the tetracarboxylic dianhydride represented by Formula (VII-5), Formula (VIII-7), and Formula (VIII-8), as described in the item [2]. Alignment agent:

R ⁴ is alkylene having 6 to 20 carbon atoms; R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene.

[7] A polyamic acid having a photosensitive group in the main chain, at least one of tetracarboxylic acid dianhydrides having a photosensitive group represented by formulas (IV-4) and (VI-8) described in [5] and a formula (VII-4) ), A mixture of at least one of tetracarboxylic dianhydrides represented by formula (VII-5), formula (VIII-7) and formula (VIII-8) is formula (VII-1) to formula described in [5]. The alignment agent as described in [2] which is a polyamic acid obtained by making it react with at least 1 of the diamine represented by (VII-3) and Formula (VIII-1)-Formula (VIII-6):

Wherein R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— Alkylene having 6 to 20 carbon atoms.

[8] The polyamic acid having a photosensitive group in the main chain thereof is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), and formula (III-) described in [4]. 1), at least one of diamines having a photosensitive group represented by formulas (IV-1) to (IV-3), formulas (V-1) and (VI-1) to (VI-7), and a formula At least one mixture selected from the diamines represented by (2) to (4) is formula (A-1), formula (A-2), formula (A-12) or formula (A) described in [4]. A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII The alignment agent according to [2], which is a polyamic acid obtained by reacting with at least one of -7) and tetracarboxylic dianhydride represented by formula (VIII-8):

Wherein A ¹ , A ² , A ³ and A ⁴ are independently cyclohexylene or phenylene; X ³ and X ⁴ are independently a single bond, alkylene having 1 to 5 carbon atoms, or —O—; X ⁵ and X ⁶ are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ —, —O— or —S—; Y ¹ is -CH _2- , -C (R ¹¹ ) (R ¹² )-, -CO- or -SO _2- , and R ¹¹ and R ¹² are independently hydrogen, alkyl having 1 to 12 carbons, or 1 carbon -12 alkyl fluorides; m1, m2, m3, m4 and n represent 0 or 1 independently. And in said cyclohexylene and phenylene, arbitrary hydrogen may be substituted by C1-C4 alkyl or benzyl, and the coupling | bonding position of these substituents is arbitrary. Provided that when A ¹ , A ² , A ³ and A ⁴ are all 1,4-phenylene, then X ³ , X ⁴ , X ⁵ and X ⁶ are not all single bonds:

Wherein X ¹ and X ² are a single bond, —O—, —COO—, —OCO—, —NH—, —CONH—, or alkylene having 1 to 12 carbon atoms; G ¹ and G ² are divalent groups containing 1 to 3 rings selected from a single bond or an aromatic ring having 6 to 12 carbon atoms and an alicyclic ring having 3 to 12 carbon atoms; R ⁶ is hydrogen, fluorine, -CN, -OH, alkyl having 1 to 30 carbon atoms, alkyl fluorinated 1 to 30 carbon atoms or alkoxy having 1 to 30 carbon atoms; When all of X ¹ , G ¹ , X ² and G ² are single bonds, R ⁶ is alkyl having 3 to 30 carbon atoms, fluorinated alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms, and G ² is single When a bond and X ² is neither a single bond nor an alkylene, R ⁶ is hydrogen or alkyl having 3 to 30 carbon atoms, and when both G ¹ and G ² are single bonds, then X ¹ , X ² and R ⁶ The total carbon number of 3 or more:

R ⁷ is hydrogen or alkyl having 1 to 12 carbons; Ring B is 1,4-phenylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms, or 1,4-cyclohexylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms; X ⁰ is a single bond or alkylene having 1 to 5 carbon atoms, and s is an integer of 0 to 3; When s is 2 or 3, a plurality of rings B may be all the same ring, may be composed of at least two different rings, a plurality of X ⁰ may be all the same group, may be composed of at least two different groups ; Z ¹ and Z ² are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ — or —O—, and t1 and t2 are independently integers from 0 to 3; when t1 is 2 or 3, a plurality of Z ¹ may all be the same group and may be composed of at least two different groups; When t2 is 2 or 3, a plurality of Z ² may all be the same group and may be composed of at least two different groups.

[9] The polyamic acid having a photosensitive group in the main chain thereof is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3) and formula (III-) as described in [4]. 1), at least one of diamines having a photosensitive group represented by formulas (IV-1) to (IV-3), formulas (V-1) and (VI-1) to (VI-7), and [6 ] At least one of the diamine represented by Formula (VII-1)-Formula (VII-3) and Formula (VIII-1)-Formula (VIII-6) which are described in], and Formula (2)-which are described in [8] A mixture with at least one selected from diamines represented by formula (4) is formula (A-1), formula (A-2), formula (A-12), or formula (A-14) described in [4]. ), Formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) And the alignment agent according to [2], which is a polyamic acid obtained by reacting with at least one of tetracarboxylic dianhydride represented by formula (VIII-8).

[10] The polyamic acid is at least one of tetracarboxylic dianhydrides in which at least one of the diamines represented by formulas (VII-1) to (VII-3) is represented by formulas (VIII-7) and (VIII-8). Tetracarboxylic acid dianhydride represented by formula (VII-4) and formula (VII-5) at least one of the polyamic acid obtained by reacting with one, or the diamine represented by Formula (VIII-1)-Formula (VIII-6) The alignment agent as described in [1] which is a polyamic acid obtained by reacting with at least 1 of:

R ⁴ is alkylene having 6 to 20 carbon atoms; R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene.

[11] A liquid crystal aligning film obtained by imparting anisotropy to a film obtained by applying the alignment agent according to [1] to a substrate by rubbing or light irradiation, and then heating to a liquid crystal temperature range of the film to increase the anisotropy of the film.

[12] Obtained by anisotropy by light irradiation to the film | membrane obtained by apply | coating the aligning agent in any one of [2]-[9] by light irradiation, and heating to the liquid crystal temperature range of a film | membrane after that, and obtaining anisotropy of a film | membrane. Liquid crystal alignment film.

[13] A liquid crystal alignment film obtained by imparting rubbing anisotropy to a film obtained by applying the alignment agent according to [10] to a substrate, and then heating to a liquid crystal temperature range of the film to increase the anisotropy of the film.

[14] A liquid crystal display device having the liquid crystal alignment film according to [11].

[15] A liquid crystal display device having the liquid crystal alignment film according to [12].

[16] A liquid crystal display device having the liquid crystal alignment film according to [13].

[17] A polyamic acid containing a structural unit represented by formula (IX) and having a liquid crystal temperature range at 100 to 300 ° C, or a precursor thereof:

R ⁵ is alkylene having 6 to 12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), And the residue of any one of diamine represented by formula (V-1) and formula (VI-1)-formula (VI-7).

[18] A polyamic acid containing a structural unit represented by formula (X) and having a liquid crystal temperature range at 100 to 300 ° C or a precursor thereof:

R ⁵ is alkylene having 6 to 12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), And the residue of any one of diamine represented by formula (V-1) and formula (VI-1)-formula (VI-7).

[19] The polyamic acid according to item [17], or a precursor thereof, wherein R ⁹ is a residue of any of the diamines represented by formulas (VIII-1) to (VIII-6).

[20] The polyamic acid according to item [18], or a precursor thereof, wherein R ⁹ is a residue of any of the diamines represented by formulas (VIII-1) to (VIII-6).

[21] A polyamic acid containing a structural unit represented by formula (IX) and a structural unit represented by formula (XI) and having a liquid crystal temperature range at 100 to 300 ° C or a precursor thereof:

R ⁵ is alkylene having 6 to 12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), A residue of any one of diamines represented by formula (V-1) and formula (VI-1) to formula (VI-7); R ¹⁰ is a residue of any of the diamines represented by formulas (VIII-1) to (VIII-6).

[22] A polyamic acid containing a structural unit represented by formula (X) and a structural unit represented by formula (XII) and having a liquid crystal temperature range at 100 to 300 ° C or a precursor thereof:

R ⁵ is alkylene having 6 to 12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), A residue of any one of diamines represented by formula (V-1) and formula (VI-1) to formula (VI-7); R ¹⁰ is a residue of any of the diamines represented by formulas (VIII-1) to (VIII-6).

The alignment agent of the present invention is a composition containing a polyamic acid and at least one polymer selected from polyimide obtained by the dehydration reaction of the polyamic acid, wherein the polymer is based on the total amount of the film forming component included in the composition. The ratio of is 50 to 100% by weight. And by depositing this composition, the film | membrane which has a liquid crystal temperature range can be formed between 100 degreeC and 300 degreeC. That is, this alignment agent is apply | coated to a board | substrate, and it forms into a film, and after rubbing or irradiating light to impart anisotropy to a film, it heats to the liquid crystal temperature range of this film, and an orientation film can be increased and an alignment film which has high orientation can be formed. By using the aligning agent containing the above-mentioned polymer as a main component, it can be made into a film with high thermal and chemical stability.

The glass transition temperature at the time of using the polyamic acid used by this invention as a polyimide is smaller than a normal polyimide because it is easy to move a polymer main chain, and is below liquid crystal temperature. Therefore, in the aligning agent of this invention which has such a polyamic acid as a main component, the film | membrane with a high imidation ratio can be obtained even by baking at comparatively low temperature. In the following description, unless otherwise stated, "polyamic acid used in the present invention" is simply referred to as "polyamic acid".

As described above, the alignment film of the present invention exhibits its performance by heating to the liquid crystal temperature range of the material. When providing anisotropy to a film | membrane by the rubbing method, an aligning agent is apply | coated to a board | substrate, a solvent is removed by preliminary baking, and baking is carried out after baking at about 200 degreeC is generally performed in order to prevent chipping of a film | membrane. However, if the chipping of the film can be prevented by the selection of the material, rubbing may be performed after the preliminary firing, and the heat treatment may be performed simultaneously for the firing and anisotropy increase at about 200 ° C.

Since the photo-alignment method can impart anisotropy to the alignment film in a non-contact manner, there is no concern about the chipping of the film. That is, the photo-alignment method is more preferable as a method of imparting anisotropy to the alignment film of the present invention, since the thermal imidization and heat treatment can be performed simultaneously after the photo-alignment using a polyamic acid. For this reason, it is preferable to select a material whose temperature of thermal imidization is within the liquid crystal temperature range.

Although the limit temperature of heat processing may be restrict | limited depending on the kind of base material, the film which has a liquid crystal temperature range in the range of 100-300 degreeC can be formed by using the aligning agent of this invention. At this time, when forming the alignment film with respect to the nematic liquid crystal used, in order to maintain the stability of an orientation, Preferably, the material which has a liquid crystal temperature range in 150-300 degreeC, More preferably, 180 degreeC-300 degreeC is selected. It is desirable to.

In order to use the photo-alignment method mentioned above, it is preferable that the alignment agent of this invention contains the polymer which has a photosensitive group. As this photoconductor, all the well-known photoconductors which have photo-alignment ability can be selected. However, when the photosensitive device which expresses orientation capability by photodimerization or photolysis is used, it is highly likely that the liquid crystal temperature range of a material will change according to light irradiation conditions. Therefore, in this invention, it is preferable to use the photoisomerization type photosensitive device.

That is, in the present invention, it is preferable to use a polymer having at least one of the following photosensitive groups in the main chain.

R ¹ , R ² and R ³ are independently aromatic divalent groups, preferred examples of which are 1,4-phenylene, 1,3-phenylene, 4,4'-biphenylene and diphenylmethane-4 , 4'-diyl. Any hydrogen of these rings may be substituted with methyl, methoxy, trifluoro methyl, methyloxycarbonyl, fluorine or chlorine. And among these groups, 1, 4- phenylene and 1, 3- phenylene are more preferable, and 1, 4- phenylene is the most preferable.

By selecting the photosensitive device represented by Formula (I)-Formula (VI), it is possible to express the characteristic of the photo-alignment agent of this invention which is large in photo-alignment property and high in sensitivity to the maximum. Although two isomers of cis or trans exist in the double bond of the photosensitive group of Formula (III) and Formula (V), the photo-alignment agent of this invention may use either of these isomers.

What is necessary is just to use the diamine and / or carboxylic dianhydride which has such a photosensitive group as a raw material in order to obtain the polyamic acid which has at least one of the photosensitive groups represented by Formula (I)-Formula (VI) in a principal chain. In order to obtain especially high photo-alignment property, it is preferable to use the raw material which has a photosensitive group in diamine.

Preferable examples of the diamine and tetracarboxylic dianhydride having such a photosensitive group include compound (I-1) to compound (I-3), compound (II-1) to compound (II-3), and compound (III-1). , Compound (IV-1) to compound (IV-4), compound (V-1), and compound (VI-1) to compound (VI-8). In addition, in the following description, tetracarboxylic dianhydride may be called acid anhydride.

In manufacturing a polyamic acid, diamine and acid anhydride which do not have a photosensitive group can be used together with said compound. At this time, in order to make it easy to reduce Tg of the polyimide obtained by the dehydration reaction of this polyamic acid, it is preferable to select the diamine or acid anhydride which can introduce C6-C20 alkylene into the polymer main chain. To further lower Tg, any -CH ₂ -of this alkylene is -O-, -NH-, -N (CH ₃ )-, -Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ -or- May be substituted with COO-. As such diamine and acid anhydride, the compound represented by the following formula (VII-1)-formula (VII-5) is especially preferable.

Here, R <^4> is C6-C20 alkylene and preferable carbon number is 6-12. R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene. Preferred R ⁵ is alkylene having 6 to 12 carbon atoms in which one -CH ₂ -may be substituted with -O-. And, R ⁵ is more preferable examples of the group -CH ₂ - is substituted a carbon number of 6 to 12 alkylene, or -C ₆ H ₁₂ without relating to - ~ -C ₁₂ H _24.

And in order to make it easy to express liquid crystal, it is also preferable to use together the aromatic ring aggregate and the diamine or acid anhydride which couple | bonded in series as much as possible with 2 amino group or 2 carboxyl group. As such diamine and acid anhydride, the compound represented by the following formula (VIII-1)-a formula (VIII-8) is especially preferable.

In this invention, diamines other than the diamine quoted by the description so far can also be used together. For example, when an oriented film is used as an oriented film for nematic liquid crystal compositions in liquid crystal display applications, it is well-known that it is excellent in what is called electrical property which shows characteristics, such as a high voltage retention ratio (VHR) and does not stick easily. Diamine of can be used.

As a preferable thing of such a well-known diamine, the diamine represented by Formula (2) is mentioned.

In formula (2), A ¹ , A ² , A ³ and A ⁴ are independently cyclohexylene or phenylene; X ³ and X ⁴ are independently a single bond, alkylene having 1 to 5 carbon atoms, or —O—; X ⁵ and X ⁶ are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ —, —O— or —S—; Y ¹ is -CH _2- , -C (R ¹¹ ) (R ¹² )-, -CO- or -SO _2- , and R ¹¹ and R ¹² are independently hydrogen, alkyl having 1 to 12 carbons, or 1 carbon Fluorinated alkyl of 12 to 12, preferably hydrogen, methyl or -CF ₃ ; m1, m2, m3, m4 and n represent 0 or 1 independently. In the cyclohexylene and phenylene, arbitrary hydrogen may be substituted with alkyl or benzyl having 1 to 4 carbon atoms, and the bonding position of these substituents is free within a chemically troubled range. Provided that when A ¹ , A ² , A ³ and A ⁴ are 1,4-phenylene, X ³ , X ⁴ , X ⁵ and X ⁶ are not single bonds.

The preferable example of the diamine represented by Formula (2) is shown next.

Among these, from a viewpoint of providing high VHR to a liquid crystal aligning film and suppressing a sticking phenomenon, Formula (2-6)-Formula (2-24), Formula (2-36), Formula (2-42), Formula ( 2-43) or the diamine represented by formula (2-48)-formula (2-52) is more preferable, and a formula (2-6), a formula (2-11), a formula (2-12), a formula ( The diamine represented by 2-13, formula (2-17), formula (2-22), formula (2-23), formula (2-24), or formula (2-49) is more preferable.

The use ratio of the diamine of the said Formula (2) in this invention can be arbitrarily selected according to the orientation and electrical characteristics made into the objective. However, when the use ratio of these diamine is large, since liquid crystallinity falls, it is preferable that this use ratio is 0-30 mol% in the quantity of the whole diamine used when synthesize | combining a polyamic acid, and is 0-10 mol% It is more preferable that is.

Another example of a diamine having no photosensitive group that can be suitably used for producing the polyamic acid is a diamine having a side chain group represented by the formula (3) or (4).

In formula (3), X ¹ and X ² are independently a single bond, -O-, -COO-, -OCO-, -NH-, -CONH- or alkylene having 1 to 12 carbon atoms; G ¹ and G ² are independently a divalent group containing 1 to 3 rings selected from a single bond or an aromatic ring having 6 to 12 carbon atoms and an alicyclic ring having 3 to 12 carbon atoms; R ⁶ represents hydrogen, fluorine, -CN, -OH, alkyl having 1 to 30 carbon atoms, fluorinated alkyl having 1 to 30 carbon atoms or alkoxy having 1 to 30 carbon atoms. Provided that when X ¹ , G ¹ , X ² and G ² are all single bonds, R ⁶ is alkyl having 3 to 30 carbon atoms, fluorinated alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms; When G ² is a single bond and X ² is neither a single bond nor an alkylene, R ⁶ is hydrogen or alkyl; In addition, when G <^1> and G <^2> are single bonds, the total carbon number of X <^1> , X <^2> and R <^6> is three or more.

In above-mentioned Formula (3), although two amino groups are couple | bonded with the carbon of a benzene ring, it is preferable that the bond position relationship of two amino groups is meta or para. The two amino groups are each preferably bonded at positions 3 and 5, or at positions 2 and 5, and particularly preferably at positions 3 and 5 when the bond position of X 1 is 1. Do.

In formula (4), R ⁷ is hydrogen or alkyl having 1 to 12 carbon atoms; Ring B is 1,4-phenylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms, or 1,4-cyclohexylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms; X ⁰ is a single bond or alkylene having 1 to 5 carbon atoms, and s is an integer of 0 to 3; When s is 2 or 3, a plurality of rings B may all be the same ring, may be composed of at least two different rings, and a plurality of X ⁰ may be all the same group, or may be composed of at least two different groups ; Z ¹ and Z ² are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ — or —O—, and t1 and t2 are independently integers from 0 to 3; when t1 is 2 or 3, a plurality of Z ¹ may all be the same group and may be composed of at least two different groups; When t2 is 2 or 3, a plurality of Z ² may all be the same group and may be composed of at least two different groups.

The preferable example of the diamine represented by Formula (3) is shown next.

In formula (3-1)-a formula (3-25), R <^20> is C1-C20 alkyl or alkoxy, Preferably it is C5-C16 alkyl. R <^21> is C1-C20 alkyl or alkoxy, Preferably it is C3-C10 alkyl. R ²² is alkyl having 4 to 20 carbons, preferably alkyl having 6 to 16 carbons. R ²³ is alkyl having 6 to 20 carbons, preferably alkyl having 8 to 20 carbons. R <^24> is C3-C20 alkyl or alkoxy, Preferably it is C5-C12 alkyl. R <^25> is C1-C20 alkyl or alkoxy, Preferably it is C3-C10 alkyl.

Among these diamines, more preferable examples are diamines represented by formulas (3-1), (3-2), (3-4), (3-5) and (3-6). , A more preferable example is diamine represented by each of Formula (3-1) and Formula (3-2).

The preferable example of the diamine represented by Formula (4) is shown next.

In formulas (4-1) to (4-16), R ²⁶ is hydrogen or alkyl having 1 to 12 carbon atoms or alkoxy, and preferably alkyl having 4 to 7 carbon atoms.

The use ratio of the diamine which has a side chain group of said Formula (3) or Formula (4) in this invention can be arbitrarily selected according to the orientation, electrical property, or pretilt angle made into the objective. In order to express a pretilt angle of 2 degrees or more especially, it is preferable to make this use ratio into 1-50 mol% in the diamine whole quantity used when manufacturing a polyamic acid, and it is more preferable to set it as 5-30 mol%. . However, when the use ratio of the diamine which has a side chain group of said (3) or (4) is large, since liquid crystallinity falls, it is preferable to set it as minimum as needed.

In order to maintain the liquid crystallinity which the alignment film of this invention has among the diamine which has a side chain group of said Formula (3) or Formula (4), Formula (3-5), Formula (3-6), or Formula (3-10) It is preferable to select the diamine.

In the present invention, at least one of siloxane-based diamines may be used in addition to the diamines described above. As a preferable example of this siloxane diamine, the diamine represented by Formula (15) is mentioned.

In formula (15), R <^30> and R <^31> is respectively independently C1-C3 alkyl or phenyl, R <^32> is C1-C6 alkylene, phenylene, or alkyl substituted phenylene, y is 1 It is an integer of -10.

As a specific example of the diamine represented by Formula (15), the following compound or polymer is mentioned.

In these formulas, the molecular weight of the polymer of Formula (15-2) is 850-3000.

0.5-30 mol% is suitable for the addition amount of these siloxane diamine with respect to the whole quantity of the diamine used as a raw material when manufacturing a polyamic acid, in order to express the said effect and to prevent the deterioration of other characteristics, 10 mol% is more suitable.

According to the required properties of the alignment film, known acid anhydrides having excellent electrical properties, such as those having high voltage retention ratio (VHR) and preventing sticking, can be used during the production of the polyamic acid.

The acid anhydride which is a raw material for polyamic acid production can be selected from a well-known compound without a restriction. The acid anhydride may belong to any one of an acid anhydride of an aromatic system (including a heteroaromatic ring system) and an acid anhydride of an aliphatic system (including a heterocyclic ring system). It is preferable that the polyimide or polyamic acid has a structure that does not contain oxygen or sulfur, such as esters or ether bonds, which are liable to cause deterioration of the electrical properties of the liquid crystal display device. Therefore, it is preferable that acid anhydride also has a structure containing no oxygen or sulfur. However, even if it has such a structure, if it is an amount within the range which does not adversely affect an electrical characteristic, there will be no problem.

Acid anhydride is represented by Formula (20).

Preferable examples of R ^{40 in} the formula (20) are tetravalent groups represented by formulas (21) to (29).

G ³ is a single bond, alkylene having 1 to 12 carbon atoms, 1,4-phenylene, or 1,4-cyclohexylene, and X ⁷ is independently a single bond or -CH _2- .

R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ are independently hydrogen, methyl, ethyl or phenyl.

Ring D ¹ is a cyclohexane ring or a benzene ring.

G ⁴ is a single bond, -CH _2- , -CH ₂ CH _2- , -O-, -CO-, -S-, -C (CH ₃ ) _2- , or -C (CF ₃ ) _2- , Ring D ² is independently a cyclohexane ring or a benzene ring.

R ⁴⁵ is hydrogen or methyl.

X ⁸ is independently a single bond or —CH ₂ —, and ｖ is 1 or 2

X ⁶ is a single bond or -CH _2- .

R ⁴⁶ is hydrogen, methyl, ethyl or phenyl, and ring D ³ is a cyclohexane ring or a benzene ring.

w1 and w2 are independently 0 or 1.

The specific example of said acid anhydride is shown next.

In these acid anhydrides, in order to maintain the liquid crystallinity of polyamic acid, Formula (A-1), Formula (A-2), Formula (A-12), Formula (A-14), and Formula (A- 18), it is preferable to use the compound of formula (A-20), formula (A-21) or formula (A-37). Moreover, from a viewpoint of improving the photo-alignment ability of an oriented film, Formula (A-1), Formula (A-2), Formula (A-12), Formula (A-14), Formula (A-18), Formula (A -20), it is preferable to use the compound of formula (A-21), formula (A-28), formula (A-30), formula (A-37) or formula (A-40), Particular preference is given to using the compound of formula -1), formula (A-12), formula (A-14) or formula (A-18). Moreover, from a viewpoint of improving VHR of a liquid crystal aligning film, or reducing coloring, Formula (A-14), Formula (A-18), Formula (A-19), Formula (A-20), Formula (A -21), formula (A-28), formula (A-29), formula (A-30), formula (A-32), formula (A-39), formula (A-40), formula (A- It is preferable to use a compound of formula 41), formula (A-43), or formula (A-44), and formula (A-14), formula (A-18), formula (A-21), or formula ( Particular preference is given to using the compounds of A-44). The acid anhydride is not limited to these, and other known compounds may be used within the scope in which the object of the present invention is achieved. Moreover, these acid anhydrides can also be used individually or in combination of 2 or more types.

In this invention, a polyamic acid is manufactured by making it react suitably by combining said diamine and acid anhydride. The first preferable examples of this polyamic acid are compound (I-1) to compound (I-3), compound (II-1) to compound (II-3), compound (III-1), which are diamines having a photosensitive group. It is a polyamic acid obtained by making at least 1 of a compound (IV-1)-a compound (IV-3), a compound (V-1), and a compound (VI-1)-a compound (VI-7) react with an acid anhydride.

Preferred examples of the acid anhydride used at this time are compound (A-1), compound (A-2), compound (A-12), compound (A-14), compound (A-18) and compound (A-20). ), Compound (A-21), compound (A-37), compound (VII-4), compound (VII-5), compound (VIII-7) and compound (VIII-8). And compound (VII-4) and compound (VII-5) are especially preferable.

Wherein R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— Alkylene having 6 to 20 carbon atoms. And R ⁵ is preferably an alkylene having 6 to 12 carbon atoms, that is, any one of -C ₆ H ₁₂ -to -C ₁₂ H _24- .

A second preferred example of the polyamic acid is a polyamic acid obtained by reacting at least one of the acid anhydrides represented by formulas (IV-4) and (VI-8) which are acid anhydrides having the above-described photosensitive group with a diamine.

Preferable examples of the diamine used at this time are diamines selected from compounds represented by formulas (VII-1) to (VII-3) and (VIII-1) to (VIII-6).

Here, R <^4> is C6-C20 alkylene and preferable carbon number is 6-12. R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene. And R ⁵ is preferably any one of -C ₆ H ₁₂ -to -C ₁₂ H _24- .

The third preferred example of the polyamic acid is compound (I-1) to compound (I-3), compound (II-1) to compound (II-3), compound (III-1) and compound (IV) described above. -1) to at least one of diamines selected from compound (IV-3), compound (V-1) and compound (VI-1) to compound (VI-7) and the above-mentioned compounds (VII-1) to compound ( VII-3) and a polyamic acid obtained by reacting a mixture of at least one of diamines selected from compounds (VIII-1) to (VIII-6) with an acid anhydride. Preferred examples of this acid anhydride include compound (A-1), compound (A-2), compound (A-12), compound (A-14), compound (A-18) and compound (A-20) described above. ), Compound (A-21), compound (A-37), compound (VII-4), compound (VII-5), compound (VIII-7) and compound (VIII-8). And when the diamine to combine with the diamine which has a photosensitive group is chosen from compound (VII-1)-compound (VII-3), especially preferable acid anhydride is compound (VIII-7) or compound (VIII-8), When the diamine to be combined with the diamine having a group is selected from compounds (VIII-1) to (VIII-6), particularly preferred acid anhydrides are compound (VII-4) or compound (VII-5).

A fourth preferred example of the polyamic acid is at least one of the acid anhydrides having a photosensitive group represented by the above-described formula (IV-4) and formula (VI-8) and formulas (VII-4), (VII-5), A polyamic acid obtained by reacting a mixture with at least one of the acid anhydrides represented by (VIII-7) and formula (VIII-8) with diamine. Preferable examples of this diamine are diamines selected from the compounds represented by formulas (VII-1) to (VII-3) and (VIII-1) to (VIII-6).

(The meaning of R ⁵ in these formulas is as described above.)

The fifth preferred example of the polyamic acid is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1) and formula (IV-) described above. 1) to at least one of the diamines having a photosensitive group represented by formula (IV-3), formula (V-1), and formula (VI-1) to formula (VI-7) and the above formulas (2) to ( It is a polyamic acid obtained by making a mixture with at least 1 chosen from the diamine represented by 4) react with an acid anhydride. Preferred examples of this acid anhydride include the above formulas (A-1), (A-2), (A-12), (A-14), (A-18) and (A-20). ), A compound represented by formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and formula (VIII-8) Acid anhydride. And compound (VII-4) and compound (VII-5) are especially preferable.

The sixth preferable example of a polyamic acid is Formula (I-1)-Formula (I-3), Formula (II-1)-Formula (II-3), Formula (III-1), and Formula (IV) which were mentioned above. -1) to at least one of the diamines having a photosensitive group represented by formula (IV-3), formula (V-1) and formula (VI-1) to formula (VI-7), formula (VII-1) described above At least one selected from the diamines represented by formulas (VII-3) and (VIII-1) to (VIII-6) and the diamines represented by the above formulas (2) to (4). Polyamic acid obtained by reacting a mixture with an acid anhydride. Preferred examples of this acid anhydride include the above formulas (A-1), (A-2), (A-12), (A-14), (A-18) and (A-20). , An acid selected from compounds represented by formulas (A-21), (A-37), (VII-4), (VII-5), (VIII-7) and (VIII-8) It is anhydride.

The seventh preferred example of the polyamic acid is at least one of the diamines represented by formulas (VII-1) to (VII-3) and tetracarboxylic dianhydride represented by formulas (VIII-7) and (VIII-8). Polyamic acid obtained by reacting at least one of these, or tetracarboxylic acid 2 represented by at least one of the diamines represented by formulas (VIII-1) to (VIII-6) and formulas (VII-4) and (VII-5) It is a polyamic acid obtained by making at least 1 of anhydride react.

The meanings of R ⁴ and R ⁵ in these formulas are as described above.

And the preferable example of the aligning agent of this invention is the aligning agent containing the polyimide obtained by the one polyamic acid chosen by the said 7 preferable polyamic acid or its dehydration reaction, but the polyamic acid selected should be two or more It may be. Moreover, as long as it is in the range which does not impair the effect of this invention, the aligning agent of this invention may contain general polyamic acid other than the said example in addition to at least one of the said seven polyamic acids. That is, in the present invention, in addition to the polyamic acid described above, polyamic acid having no photosensitive group in the main chain or between 100 ° C and 300 ° C as long as the condition of forming a film having a liquid crystal temperature range is satisfied between 100 ° C and 300 ° C. The polyamic acid etc. which cannot form the film | membrane which has a liquid crystal temperature range can be used together. When using polyamic acid other than such said example, the ratio is less than 50 weight% in the film formation component whole quantity in an aligning agent, Preferably it is less than 20 weight%.

The alignment agent of the present invention may further contain an organosilicon compound from the viewpoint of adjusting the adhesion of the alignment film to the glass substrate. Examples of the organosilicon compound include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, vinyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- ( Aminoethyl) -3-aminopropyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyl dimethoxy Silane coupling agents such as silane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and silicone oils such as dimethylpolysiloxane, polydimethylsiloxane, and polydiphenylsiloxane.

The addition ratio of this organosilicon compound with respect to an aligning agent will not be restrict | limited especially if it is a range from which the effect of this invention is acquired. However, when a large amount of the said organosilicon compound is added, when the orientation film is used, the orientation defect of a liquid crystal may generate | occur | produce. Therefore, when adding an organosilicon compound, it is preferable that it is the range of 0.01-5 weight% with respect to the total amount of the polymer component contained in an aligning agent, Especially preferably, it is the range of 0.1-3 weight%.

The alignment agent of the present invention may further contain a compound having two or more functional groups reacting with the carboxylic acid moiety of the polyamic acid, and a so-called crosslinking agent, from the viewpoint of preventing deterioration with time and deterioration due to the environment. Examples of such crosslinking agents include polyfunctional epoxy and isocyanate materials such as those described in Japanese Patent No. 3049699, Japanese Patent Application Laid-Open No. 2005-275360, Japanese Patent Application Laid-open No. Hei 10-212484, and the like. Can be.

The crosslinking agent itself reacts to form a polymer having a mesh structure, and a crosslinking agent for improving the film strength of polyamic acid or polyimide can also be used for the same purpose as described above. As such a crosslinking agent, the polyfunctional vinyl ether, maleimide, bisaryl nadiiimide derivative, etc. which are described in Unexamined-Japanese-Patent No. 10-310608, Unexamined-Japanese-Patent No. 2004-341030, etc. are mentioned. . The preferable ratio of these crosslinking agents is 0-50 weight% with respect to the total amount of a polymer component, More preferably, it is 0-30 weight%.

The alignment agent of this invention contains the solvent which has the ability to melt | dissolve polyamic acid. The solvent concerned broadly includes a solvent usually used in the production or use of polyamic acid or derivatives thereof, and can be appropriately selected depending on the purpose of use. When these solvents are illustrated, it is as follows.

Examples of aprotic polar organic solvents that are good solvents for polyamic acids include N-methyl-2-pyrrolidone (NMP), dimethylimidazolidinone, N-methylcaprolactam, and N-methylpropionamide. , N, N-dimethylacetamide, dimethyl sulfoxide, N, N-dimethylformamide (DMF), N, N-diethylformamide, N, N-diethylacetamide (DMAc), and γ-butyro Lactone, such as lactone (GBL), is mentioned.

As solvents other than the above-mentioned solvents, examples of other solvents for the purpose of improving the coating properties include alkyl lactate, 3-methyl-3-methoxybutanol, tetralin, isophorone, ethylene glycol monobutyl ether (BCS), and the like. Diethylene glycol monoalkyl ethers such as ethylene glycol monoalkyl ether and diethylene glycol monoethyl ether, propylene glycol monoalkyl ethers such as ethylene glycol monoalkyl and phenyl acetate, triethylene glycol monoalkyl ether and propylene glycol monobutyl ether, and marron Ester compounds, such as dialkyl glycol monoalkyl ethers, such as dialkyl maronic acid, such as diethyl acid, and dipropylene glycol monomethyl ether, and these glycol monoethers, are mentioned. Among these, NMP, dimethyl imidazolidinone, GBL, BCS, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, etc. can be used especially preferably for the said solvent.

The alignment agent of the present invention may further contain various additives as desired. For example, when it is necessary to further improve applicability, a surfactant according to this purpose may be contained, and when an antistatic agent needs to be further improved, an antistatic agent may be contained in an appropriate amount.

It is preferable that the density | concentration of the polyamic acid in the aligning agent of this invention is 0.1-40 weight%. When apply | coating this aligning agent to a board | substrate, the operation which dilutes the polyamic acid contained with the solvent in advance may be needed for adjustment of a film thickness.

Solid content concentration in the orientation agent of this invention is not specifically limited, What is necessary is just to select the optimal value according to the following various coating methods. Usually, in order to suppress the nonuniformity, pinhole, etc. at the time of application | coating, it is 0.1-30 weight% with respect to a varnish weight, More preferably, it is 1-10 weight%.

The alignment film of this invention is obtained by providing anisotropy to a film | membrane by rubbing or light irradiation to the film | membrane obtained by apply | coating said aligning agent to a board | substrate, and heating it to the liquid crystal temperature range of a film | membrane after that, and obtaining it.

It is preferable to be manufactured by the following steps from a viewpoint of expressing sufficient orientation at this time.

(1) The varnish is applied onto a substrate by a brushing method, dipping method, spinner method, spray method, printing method, or the like.

(2) The film formed on the board | substrate is heated to 50-120 degreeC, Preferably it is 80-100 degreeC, and a solvent is evaporated.

(3) Light is irradiated to the film to orient the polyamic acid in the film.

(4) The said film which orientated polyamic acid is heated to 150-300 degreeC, Preferably it is 180-250 degreeC, and imidizes.

On the other hand, when a predetermined pretilt angle is to be expressed in a liquid crystal display element using an alignment film, a method of irradiating linearly polarized light from an arbitrary angle with respect to a substrate when irradiating light, or linearly polarized light from a vertical direction with respect to a base It can carry out by the method which combines irradiation and unpolarized irradiation from arbitrary angles.

In the manufacture of the alignment film of the present invention, linearly polarized light is used for the alignment of the polyamic acid. The polyamic acid backbone is oriented in a direction perpendicular to the polarization direction of linearly polarized light by irradiation of linearly polarized light. The said linearly polarized light will not be specifically limited if it is light which can orientate the polyamic acid in the said film | membrane. The alignment film of the present invention can align the film by light irradiation of low energy. It is preferable that the irradiation amount of linearly polarized light in the photo-alignment process of the said polyamic acid is 0.5-10J / cm <2>. Moreover, it is preferable that the wavelength of linearly polarized light is 300-400 nm. Although the irradiation angle with respect to the film surface of linearly polarized light is not specifically limited, When it wants to express the strong orientation control force with respect to a liquid crystal, it is more preferable from a viewpoint of shortening an orientation processing time that it is as perpendicular | vertical as possible with respect to a film surface.

Moreover, in manufacture of the oriented film of this invention, the light irradiated to the said film | membrane may be polarized light or unpolarized light, when it wants to express a pretilt angle. When it is desired to express the pretilt angle, the irradiation amount of light irradiated to the film is preferably 0.5 to 10 J / cm 2, and the wavelength is preferably 300 to 400 nm. Although the irradiation angle with respect to the film surface of the light irradiated to the said film | membrane in the case of expressing a pretilt angle is not specifically limited, It is more preferable from a viewpoint of shortening an orientation processing time that it is 30-60 degree.

The alignment film of the present invention is characterized by having particularly large anisotropy of orientation. The magnitude of such anisotropy can be evaluated by the method using polarization IR as described in Unexamined-Japanese-Patent No. 2005-275364. Moreover, it can also evaluate by the method using ellipsometry as shown in the following Example. In the case where the alignment film of the present invention is used as the alignment film for the liquid crystal composition, it is considered that the material having the larger anisotropy of the film has a larger alignment regulating force with respect to the liquid crystal composition.

The alignment film of this invention can be used for orientation control of an optical compensation material and all other liquid crystal materials other than the orientation use of the liquid crystal composition for liquid crystal displays. Moreover, since the oriented film of this invention has a large anisotropy, it can be used independently for an optical compensation material use.

The present invention provides a pair of substrates arranged oppositely, an electrode formed on one or both sides of opposing surfaces of each of the pair of substrates, and a liquid crystal formed on opposing surfaces of each of the pair of substrates. The liquid crystal display element which has an alignment film and the liquid crystal layer formed between the said pair of board | substrate WHEREIN: The said liquid crystal aligning film provides the liquid crystal display element which is the alignment film of this invention.

The electrode is not particularly limited as long as it is an electrode formed on one surface of the substrate. As such an electrode, ITO, a metal vapor deposition film, etc. are mentioned, for example. Moreover, the electrode may be formed in the whole surface of one side of a board | substrate, for example, may be formed in the patterned desired shape. As said desired shape of an electrode, a comb-tooth type | mold or a zigzag structure etc. are mentioned, for example. An electrode may be formed in one board | substrate of a pair of board | substrates, and may be formed in both board | substrates. Formation of an electrode differs according to the kind of liquid crystal display element, For example, in the case of an IPS type liquid crystal display element, an electrode is arrange | positioned at one side of the said pair of board | substrates, and in the case of other liquid crystal display elements, the said Electrodes are disposed on both sides of the pair of substrates. The liquid crystal alignment film is formed on the substrate or the electrode.

The said liquid crystal layer is formed in the form which a liquid crystal composition is clamped by the said pair of board | substrate which the surface in which the liquid crystal aligning film was formed opposes. In formation of a liquid crystal layer, the spacer which forms an appropriate space | interval between said pair of board | substrates, such as microparticles | fine-particles and a resin sheet, can be used as needed. It does not specifically limit to the said liquid crystal composition, A well-known liquid crystal composition can be used.

Although the orientation film of this invention can improve the characteristic with respect to all the well-known liquid crystal compositions, when a liquid crystal display element is formed as a liquid crystal aligning film, the orientation film of this invention manufactured by the method mentioned above especially carries out a rubbing process. The effect is large for the improvement of the orientation defect of the big screen display which is difficult to carry out. Such a large screen display is driven and controlled by the TFT. Moreover, the liquid crystal composition used for such a TFT type | mold liquid crystal display element is Unexamined-Japanese-Patent No. 3086228, Unexamined-Japanese-Patent No. 5-53735, and Unexamined-Japanese-Patent No. 9-255956. It is described in the publication. Therefore, it is preferable to use the alignment film of this invention in combination with the liquid crystal composition as described in these.

As for the pretilt angle in the liquid crystal display element of this invention, the liquid crystal characteristic evaluation apparatus OMS-CA3 type | mold by Nakae Seiki Co., Ltd. is used, for example, Journal of Applied Physics, Vol. 48, No. 5, p. It can be measured according to the crystal rotation method described in 1783-1792 (1977).

The liquid crystal display element of this invention is excellent in the electrical characteristic regarding the reliability of a liquid crystal display element. As such electrical characteristics, voltage retention ratio and ion density are mentioned.

The voltage retention ratio VHR is a ratio at which the voltage applied to the liquid crystal display element is maintained in the liquid crystal display element between frame periods, and shows the display characteristics of the liquid crystal display element. The liquid crystal display element of this invention uses the square wave of 5V and frequency 30Hz, the voltage retention ratio measured on 60 degreeC temperature conditions is 90.0% or more, and uses the square wave of 5V and frequency 0.3Hz, and uses the temperature of 60 degreeC. It is more preferable from the viewpoint of preventing display failure that the voltage holding ratio measured under the conditions is 85.0% or more.

The ion density is a transient current other than due to the driving of the liquid crystal generated when a voltage is applied to the liquid crystal display element, and represents the magnitude of the concentration of the ionic impurities contained in the liquid crystal in the liquid crystal display element. As for the liquid crystal display element of this invention, it is more preferable that an ion density is 500pC or less from a viewpoint of preventing the sticking of a liquid crystal display element.

[Example]

Hereinafter, although an Example and a comparative example demonstrate this invention, this invention is not limited to these Examples. Pyromellitic anhydride (PMDA, Compound (A-1)), 1,2,3,4-cyclobutanetetracarboxylic acid (CBTA, Compound (A-14)), and Compound (2-13) are commercially available compounds. Purified by recrystallization and used in the experiment. 1,8-diaminooctane (DAO, compound (VII-1-1)) was used by distilling a commercial item. Compound (II-1) and Compound (A-21) were synthesized according to Japanese Patent Publication No. Hei 5-65530 and Japanese Patent Application Publication No. So 58-109479, respectively. The following compound (VII-2-1), compound (VII-2-2), and compound (VII-5-1) are disclosed in Japanese Patent Application Laid-open No. Hei 11-160712, and Bulletin de la Societe Chimique de France , 9-10, Pr. 2, 2195 (1975). Compound (VIII-5) and compound (VIII-6) were used in the experiment without purifying a commercial item. Compound (VIII-8) was used for the experiment by recrystallizing a commercial item from ethanol. Compound (2-22) and Compound (3-5-1) were the same as those described in Journal of Polymer Science Part A: Polymer Chemistry, 30 (6), 1099 (1992), Japanese Patent Application Publication No. 2002-162630 It synthesize | combined by the method of. Compound (A-21) was synthesized according to Japanese Patent Application Laid-open No. 58-109479. The polymer was produced in a nitrogen stream.

For light irradiation, ultraviolet rays with a wavelength of 300 to 380 nm were irradiated using a 250W high-pressure mercury lamp sold from Hiroshima. Irradiation was performed in room temperature and air.

The evaluation method of the liquid crystal display element used by the Example below is shown.

<Retardation and film thickness measurement of alignment film>

The spectroscopic ellipsometer M-2000U (manufactured by J.A. Woollam Co. Inc.) was used. In the case of this example, the retardation value of the membrane increases in proportion to the degree of orientation of the polymer backbone. That is, what has a big retardation value has a big orientation degree.

<Measurement of UV-Vis Spectrum>

It measured on the basis of the glass substrate which did not form an alignment film using the UV-Vis spectrum measuring apparatus (Japan spectroscopy V-660).

<Voltage maintenance ratio>

It carried out by the method as described in "The 14th liquid-crystal discussion meeting notice p78 (1988)", such as a water bottle. The measurement was performed by applying a square wave having a wave height of 4.5 V to the cell. The measurement was performed at 60 degreeC. This value is an index indicating how much the applied voltage is held after the frame period, and when this value is 100%, it indicates that all charges are held.

<Ion amount measurement (ion density) in liquid crystal>

According to the method described in the application physics, Vol. 65, No. 10, 1065 (1996), measurements were made using a Toyo Technica Co., Ltd. liquid crystal property measurement system type 6254. A triangular wave with a frequency of 0.01 Hz was used and measured at a voltage range of ± 10 V and a temperature of 60 ° C. If the ion density is large, problems such as seizure due to ionic impurities are likely to occur. In other words, the ion density is a physical property value that is an index for predicting seizure occurrence.

<Viscosity>

It measured using the rotational viscometer (TV-22L, the Toyo Corporation make).

<Weight average molecular weight (Mw)>

As for the weight average molecular weight (Mw) of the polyamic acid in a liquid crystal aligning agent, 0.6 weight% phosphoric acid containing DMF was used as an eluate using gel permeation chromatography (GPC), column temperature 50 degreeC, polystyrene as a standard solution. It was measured by. As the column, Shodex GF-7M HQ (manufactured by Wawa Denki Co., Ltd.) was used.

<Confirmation of polymer liquid crystal>

The thin film (film thickness about 70 nm) formed into the board | substrate was baked at 230 degreeC for 10 minutes, and observed with the polarization microscope. And the temperature rise rate was 3 degree-C / min.

<Glass transition temperature>

It measured using the differential scanning calorimetry apparatus (DSC). The temperature rise rate was 8 degree-C / min.

<Black level confirmation of cell>

Polarization microscope observation was performed about the created cell, and the determination was according to the following table | surfaces.

Synthesis Example 1

<Synthesis of Compound (VII-2-3)>

It synthesize | combined by the same method as compound (VII-2-2). Melting point; 98.0-99.2 ° C.

[Synthesis Example 2]

<Synthesis of Compound (VII-4-1)>

4-bromophthalic acid diethyl ester (50 g, 166 mmol, 1,7-octadiyne (8.7 g, 82 mmol), dichlorotriphenylphosphine palladium (II) (290 mg, 0.41 mmol), and copper iodide (158 mmol, 0.83 mmol) was refluxed in triethylamine (200 ml) for 4 hours under a stream of nitrogen, and after completion of the reaction, toluene (500 ml) and pure water (500 ml) were added and extraction was carried out The organic layer was purified with pure water (300 ml). After washing once, the mixture was dried over anhydrous magnesium sulfate, filtered and the solvent was distilled off under reduced pressure to obtain 1,4-bis (3,4-dicarboxyphenyl) ethynylbutanetetraethyl ester as a target product. Yield 95% This compound was used for the next reaction as it was without purification.

5 wt% Pd / C (2.1 g) was added to 1,4-bis (3,4-dicarboxyphenyl) ethynylbutanetetraethyl ester (42 g, 77 mmol), in a toluene / ethanol mixed solvent (300 ml / 300 ml), The hydrogenation reaction was performed by the hydrogen pressure 720MPa. After completion | finish of reaction, the catalyst was isolate | separated by filtration and the solvent was distilled off under reduced pressure. The residue was purified by column chromatography (silica gel / toluene: ethyl acetate = 10: 1 v / v) to obtain the target 1,8-bis (3,4-dicarboxyphenyl) octanetetraethyl ester. Quantity 43g, yield 100%.

1,8-bis (3,4-dicarboxyphenyl) octanetetraethyl ester (43 g, 77 mmol) was dissolved in ethanol (250 ml), 5.7% aqueous sodium hydroxide solution (250 ml) was added, and the mixture was refluxed for 2 hours. After the reaction, the solvent was distilled off under reduced pressure, and concentrated hydrochloric acid was added until the pH became 1. The resulting precipitate was filtered off, and then the precipitate was washed three times with pure water (200 ml). The obtained crystal was dried under reduced pressure to obtain 1,8-bis (3,4-dicarboxyphenyl) octane. Quantity 31g, yield 90%.

Acetic anhydride (50 ml) was added to 1,8-bis (3,4-dicarboxyphenyl) octane (10 g, 23 mmol), and the mixture was refluxed for 2 hours. After distilling off anhydrous acetic acid under reduced pressure, cyclohexane (50 ml) was added to the residue, and the resulting precipitate was filtered. Compound (VII-4-1) was obtained by drying the obtained crystals under reduced pressure. Yield 9.2 g, yield 97%. Melting point; 109.7-111.2 degreeC.

¹ H NMR (500 Hz, CDCl ₃ ): δ (ppm) 7.92 (d, 4H, J = 7.80 Hz), 7.70 (d, 4H, J = 8.1 Hz), 2.82 (t, 4H, J = 7.65 Hz), 1.3-1.7 (m, 12H)

[Synthesis Example 3]

<Production of Polyamic Acid Varnish A>

Compound (II-1) (0.1818 g, 0.7827 mmol) was dissolved in N-methyl-2-pyrrolidone (NMP, 3.0 g), and compound (VII-4-1) (0.3182 g, 0.7829 mmol) was added to room temperature. It added while maintaining below. After stirring overnight, varnish A was prepared by adding NMP (3.5 g) and ethylene glycol monobutyl ether (BSC, 3.0 g). The viscosity of varnish A was 49.8 mPa * s. The weight average molecular weight of the polyamic acid of this varnish was 74,000, and the liquid crystal phase existed in the range of 200-300 degreeC.

Synthesis Example 4-14

<Production of Polyamic Acid Varnishes B to L>

With the raw material composition shown in Table 1, varnishes B-L of polyamic acid were manufactured according to the method similar to the synthesis example 1, and the physical properties were measured similarly to the synthesis example 1. The brackets indicate mole%. And when all these varnishes confirmed the liquid crystal phase by the said measuring method, the liquid crystal phase existed in the range of 170-250 degreeC.

<Table 1>

Example 1

1.0 g of varnish A was weighed out to the sample bottle, and NMP / BC = 1/1 (weight ratio) was added to make 1.67 g. About 3 weight% of this polyamic-acid solution was dripped on the transparent glass substrate, and it apply | coated by the spinner method (2,000 rpm, 15 second). After coating, the substrate was heated at 80 ° C. for 3 minutes, the solvent was evaporated, and linearly polarized light was irradiated through a polarizing plate (about 1.3 J / cm 2 at 365 nm). The board | substrate after light irradiation was heat-processed at 210 degreeC for 15 minutes in oven, and the alignment film A of about 100 nm of film thickness was obtained. It was 12.9 nm when the retardation of this alignment film A was measured.

EXAMPLES 2-6

Using the varnish shown in Table 2, the alignment films B-F were obtained by the method similar to Example 1. The result of having measured the retardation is shown together with the result of Example 1.

<Table 2>

[Example 7]

An alignment film M was prepared in the same manner as in Example 1 except that varnish M, in which 0.5 g of varnish A and varnish B were each mixed instead of varnish A, was used. The retardation value of this alignment film M was 30.5 nm.

Comparative Example 1

Compound (II-1) (2.6432 g, 11.38 mmol) was dissolved in NMP (35.0 g) and PMDA (1.2410 g, 5.690 mmol) and CBTA (1.1158 g, 5.690 mmol) were added keeping the temperature below room temperature. After stirring at room temperature overnight, NMP (35 g) and BSC (25 g) were added. Its viscosity was 120 mPa * s. The solution was stirred at 60 ° C. for about 4 hours to obtain varnish N having a viscosity of 28.0 mPa · s. The weight average molecular weight of the polyamic acid of this varnish was 37,000, and glass transition temperature (Tg) was higher than 300 degreeC.

Using varnish N, the alignment film N was obtained by the same method as Example 1, and its retardation was measured. The result was 0.4 nm.

Comparative Example 2

Compound (VI-1) was used instead of compound (II-1) and else a varnish P having a viscosity of 34.0 mPa · s was obtained in the same manner as in Comparative Example 1. The weight average molecular weight of the polyamic acid of this varnish was 54,000, and glass transition temperature (Tg) was higher than 300 degreeC.

Using varnish P, the alignment film P was obtained by the same method as Example 1, and its retardation was measured. The result was 0.8 nm.

When Examples and Comparative Examples 1 and 2 are compared, the retardation value of the alignment film of the present invention obtained by using the polymer of the present invention is very large even at a small amount of irradiation energy compared to the alignment film produced from a polymer having no liquid crystallinity. It can be seen that it has.

[Example 8]

An alignment film A having a thickness of about 100 nm was obtained in the same manner as in Example 1, except that the glass substrate was replaced with a transparent glass substrate provided with an ITO electrode on one surface. The liquid crystal composition is placed between two substrates on which the alignment films are formed on the ITO electrode so that the polarization directions of the linearly polarized light irradiated with respect to the respective alignment films are parallel to each other, and the surfaces on which the alignment films are formed are opposed to each other. The space | gap for injecting this was formed and bonded, and the liquid crystal cell A (liquid crystal display element) with a cell thickness of 7 micrometers was assembled. And liquid crystal composition A shown below was injected into these cells.

<Liquid crystal composition A>

This liquid crystal cell A was observed by visual observation, but the so-called flow orientation in which the liquid crystals were aligned along the direction in which the liquid crystals flowed was not observed at all. When the polarization microscope was made into the cross nicol state and the liquid crystal cell A was rotated, the clear and dark state was observed. The pretilt angle of this liquid crystal cell A was 0.0 degrees. The VHR (voltage retention ratio) and ion density were 99.0% (30 Hz), 85.0% (0.3 Hz), and 120 pC.

Moreover, although the black level of this liquid crystal cell A was observed, although small millet nonuniformity was seen in all the regions which were observed, it was a favorable black level.

[Example 9]

Liquid crystal cell B was manufactured by the method similar to Example 8 except having replaced varnish B with used varnish. The pretilt angle of this liquid crystal cell B was 0.0 degrees. The VHR (voltage retention ratio) and ion density were 92.2% (30 Hz), 76.3% (0.3 Hz), and 340 pC.

Moreover, although the black level of this liquid crystal cell B was observed, the millet type nonuniformity was not seen at all in the observed area | region, and it was very favorable black level.

[Example 10]

Liquid crystal cell F was produced in the same manner as in Example 8 except that the used varnish was replaced with varnish F. The pretilt angle of this liquid crystal cell F was 0.0 degrees. The VHR (voltage retention ratio) and ion density were 99.2% (30 Hz), 85.3% (0.3 Hz), and 80 pC.

Although the black level of this liquid crystal cell F was observed, the millet nonuniformity was not seen at all in the observed area | region, and it was very favorable black level.

[Example 11]

Liquid crystal cell L was manufactured in the same manner as in Example 8 except that the used varnish was replaced with varnish L. The pretilt angle of these liquid crystal cells L was 0.0 degrees. The VHR (voltage retention ratio) and ion density were 99.4% (30 Hz), 88.2% (0.3 Hz), and 35 pC.

Moreover, although the black level of this liquid crystal cell L was observed, the millet nonuniformity was not seen at all in the observed area | region, and it was very favorable black level.

[Example 12]

Liquid crystal cell M was produced in the same manner as in Example 8 except that the used varnish was replaced with varnish M. The pretilt angle of these liquid crystal cells M was 0.1 degrees. The VHR (voltage retention ratio) and ion density were 99.0% (30 Hz), 82.1% (0.3 Hz) and 120 pC.

Moreover, although the black level of this liquid crystal cell M was observed, the millet nonuniformity was not seen at all in the observed region, and it was very favorable black level.

[Comparative Example 3]

Liquid crystal cell N was manufactured in the same manner as in Example 8 except that the used varnish was replaced with varnish N. The pretilt angle of this liquid crystal cell N was 0.1 degrees. The VHR (voltage retention ratio) and ion density were 99.1% (30 Hz), 76.0% (0.3 Hz), and 300 pC.

Moreover, although the black level of this liquid crystal cell N was observed, it was the black level which was very poor compared with the liquid crystal display element using the orientation film of this invention seen in all the area | region which a big mill type nonuniformity was observed.

[Comparative Example 4]

Liquid crystal cell P was manufactured in the same manner as in Example 8 except that the used varnish was replaced with varnish P. The pretilt angle of this liquid crystal cell P was 0.0 degrees. The VHR (voltage holding ratio) and ion density were 92.4% (30 Hz), 85.3% (0.3 Hz), and 110 pC.

Moreover, although the black level of this liquid crystal cell P was observed, it was the black level which was seen in all the area | regions where big mill rice nonuniformity was observed, compared with the liquid crystal display element using the alignment film of this invention.

[Example 13]

After the varnish A was spin-coated on a transparent glass substrate provided with an ITO electrode on one side in the same manner as in Example 1, the substrate was then heated to 80 ° C. for 3 minutes, the solvent was evaporated, and then 210 ° C. in an oven. And calcined for 15 minutes. The obtained polyimide film of about 100 nm in thickness was subjected to rubbing (indentation; 0.3 mm, stage transfer speed; 60 m / s, rotation speed; 1000 rpm, rubbing cloth; YA-18-R (rayon)). Thereafter, the alignment film was ultrasonically cleaned in ultrapure water for 5 minutes and then dried at 200 ° C. for 15 minutes in an oven.

Two substrates on which the alignment films are formed on the ITO electrode are arranged so that the rubbing direction is antiparallel to the respective alignment films, and the surfaces on which the alignment films are formed are opposed to each other, and the liquid crystal composition is injected between the opposite alignment films. The voids were formed and bonded to form a liquid crystal cell Ar having a cell thickness of 7 µm. And the said liquid crystal composition A was injected into these cells.

The pretilt angle of this liquid crystal cell Ar was 0.3 degrees, and VHR (voltage retention ratio) and ion density were 98.7% (30 Hz), 80.2% (0.3 Hz), and 230 pC. Moreover, although the black level of this liquid crystal cell Ar was observed, the defect by rubbing was not seen at all in the observed area | region, and it was very favorable black level.

Example 14

Liquid crystal cell Jr having a cell thickness of 7 μm was assembled in the same manner as in Example 13 except that varnish J was used instead of varnish A. The pretilt angle of this liquid crystal cell Jr was 0.5 degree, VHR (voltage retention ratio) and ion density were 99.1% (30 Hz), 87.5% (0.3 Hz), and 78 pC.

Moreover, although the black level of this liquid crystal cell Jr was observed, the defect by rubbing was not seen at all in the observed area | region, and it was very favorable black level.

As described above, when the alignment film of the present invention is applied to the alignment film for liquid crystal display elements, the black level can be greatly improved. It can also be seen that it has sufficient electrical properties that can be used practically.

Claims (22)

A composition containing a polyamic acid and at least one polymer selected from polyimides obtained by a dehydration reaction of the polyamic acid, wherein the polymer has alkylene having 6 to 20 carbon atoms in the structural unit of the main chain and is contained in the composition. An orientation agent which can form the film which has a liquid-crystal temperature range between 100-300 degreeC by forming this composition into 50-100 weight% on the basis of the whole quantity of a film formation component, and forming this composition. The method of claim 1,
The alignment agent whose polyamic acid is the polyamic acid which has a photosensitive group in a principal chain. The method of claim 2,
An aligning agent wherein said photosensitive group is at least one of the groups represented by formulas (I) to (VI):

In the formula, R ¹ , R ² and R ³ are independently aromatic divalent groups. The method of claim 2,
The polyamic acid which has a photosensitive group in the said main chain is Formula (I-1)-Formula (I-3), Formula (II-1)-Formula (II-3), Formula (III-1), Formula (IV-1) ) At least one of the diamines having a photosensitive group represented by formula (IV-3), formula (V-1) and formula (VI-1) to formula (VI-7) is formula (A-1), formula ( A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII -4), an alignment agent which is a polyamic acid obtained by reacting with at least one of tetracarboxylic dianhydride represented by formula (VII-5), formula (VIII-7) and formula (VIII-8):

In formula, R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO—. Alkylene having 6 to 20 carbon atoms. The method of claim 2,
The polyamic acid which has a photosensitive group in the said main chain has at least one of tetracarboxylic dianhydride which has a photosensitive group represented by Formula (IV-4) and Formula (VI-8)-Formula (VII-1)-Formula (VII-3) ) And a polyamic acid obtained by reacting with at least one of the diamines represented by formulas (VIII-1) to (VIII-6):

Wherein R ⁴ is alkylene having 6 to 20 carbon atoms; and R ⁵ is any -CH ₂ -is -O-, -NH-, -N (CH ₃ )-, -Si (CH ₃ ) ₂ OSi ( CH ₃ ) alkylene having 6 to 20 carbon atoms which may be substituted with ₂ -or -COO-

. The method of claim 2,
The polyamic acid which has a photosensitive group in the said main chain is Formula (I-1)-Formula (I-3), Formula (II-1)-Formula (II-3), Formula (III-1), Formula (IV-1) ) At least one of the diamines having a photosensitive group represented by formula (IV-3), formula (V-1) and formula (VI-1) to formula (VI-7) and formula (VII-1) to formula (VII -3) and a mixture with at least one of the diamines represented by formulas (VIII-1) to (VIII-6) are formulas (A-1), (A-2), (A-12), and (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula ( An alignment agent which is a polyamic acid obtained by reacting with at least one of VIII-7) and tetracarboxylic dianhydride represented by formula (VIII-8):

In the formula, R ⁴ is alkylene having 6 to 20 carbon atoms; R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene;

In formula, R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO—. Alkylene having 6 to 20 carbon atoms. The method of claim 2,
The polyamic acid having a photosensitive group in the main chain includes at least one of tetracarboxylic dianhydrides having a photosensitive group represented by formulas (IV-4) and (VI-8), and formulas (VII-4) and (VII-5) , A mixture with at least one of tetracarboxylic dianhydride represented by formula (VIII-7) and formula (VIII-8) is formula (VII-1) to formula (VII-3) and formula (VIII-1) to An aligning agent, which is a polyamic acid obtained by reacting with at least one of the diamines represented by formula (VIII-6):

In formula, R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO—. Alkylene having 6 to 20 carbon atoms;

In the formula, R ⁴ is alkylene having 6 to 20 carbon atoms; R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene;

. The method of claim 2,
The polyamic acid which has a photosensitive group in the said main chain is Formula (I-1)-Formula (I-3), Formula (II-1)-Formula (II-3), Formula (III-1), Formula (IV-1) ) To at least one of the diamines having a photosensitive group represented by formula (IV-3), formula (V-1) and formula (VI-1) to formula (VI-7) and formula (2) to formula (4) A mixture with at least one selected from the diamines represented is formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula ( A-20), tetra () represented by formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and formula (VIII-8) An alignment agent which is a polyamic acid obtained by reacting with at least one of carboxylic dianhydrides:

Wherein A ¹ , A ² , A ³ and A ⁴ are independently cyclohexylene or phenylene; X ³ and X ⁴ are independently a single bond, alkylene having 1 to 5 carbon atoms, or —O—; X ⁵ and X ⁶ are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ —, —O— or —S—; Y ¹ is -CH _2- , -C (R ¹¹ ) (R ¹² )-, -CO- or -SO _2- , and R ¹¹ and R ¹² are independently hydrogen, alkyl having 1 to 12 carbons, or 1 carbon -12 alkyl fluorides; m1, m2, m3, m4 and n independently represent 0 or 1, and in the cyclohexylene and phenylene, any hydrogen may be substituted with alkyl or benzyl having 1 to 4 carbon atoms, and The binding position is arbitrary, provided that when A ¹ , A ² , A ³ and A ⁴ are all 1,4-phenylene, then X ³ , X ⁴ , X ⁵ and X ⁶ are not all single bonds:

Wherein X ¹ and X ² are a single bond, —O—, —COO—, —OCO—, —NH—, —CONH—, or alkylene having 1 to 12 carbon atoms; G ¹ and G ² are divalent groups containing 1 to 3 rings selected from a single bond or an aromatic ring having 6 to 12 carbon atoms and an alicyclic ring having 3 to 12 carbon atoms; R ⁶ is hydrogen, fluorine, -CN, -OH, alkyl having 1 to 30 carbon atoms, alkyl fluorinated 1 to 30 carbon atoms or alkoxy having 1 to 30 carbon atoms; When all of X ¹ , G ¹ , X ² and G ² are single bonds, R ⁶ is alkyl having 3 to 30 carbon atoms, fluorinated alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms, and G ² is single When a bond and X ² is neither a single bond nor an alkylene, R ⁶ is hydrogen or alkyl having 3 to 30 carbon atoms, and when both G ¹ and G ² are single bonds, then X ¹ , X ² and R ⁶ Has a total carbon of 3 or more:

In the formula, R ⁷ is hydrogen or alkyl having 1 to 12 carbon atoms; Ring B is 1,4-phenylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms, or 1,4-cyclohexylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms; X ⁰ is a single bond or alkylene having 1 to 5 carbon atoms, and s is an integer of 0 to 3; When s is 2 or 3, a plurality of rings B may be all the same ring, may be composed of at least two different rings, a plurality of X ⁰ may be all the same group, may be composed of at least two different groups ; Z ¹ and Z ² are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ — or —O—, and t1 and t2 are independently integers from 0 to 3; when t1 is 2 or 3, a plurality of Z ¹ may all be the same group and may be composed of at least two different groups; when t2 is 2 or 3, a plurality of Z ² may all be the same group and may be composed of at least two different groups;

In formula, R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO—. Alkylene having 6 to 20 carbon atoms. The method of claim 2,
The polyamic acid which has a photosensitive group in the said main chain is Formula (I-1)-Formula (I-3), Formula (II-1)-Formula (II-3), Formula (III-1), Formula (IV-1) ) At least one of the diamines having a photosensitive group represented by formula (IV-3), formula (V-1) and formula (VI-1) to formula (VI-7) and formula (VII-1) to formula (VII -3) and a mixture of at least one of the diamines represented by formulas (VIII-1) to (VIII-6) and at least one selected from the diamines represented by formulas (2) to (4), A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A -37), an orientation that is a polyamic acid obtained by reacting with at least one of tetracarboxylic dianhydrides represented by formulas (VII-4), (VII-5), (VIII-7) and (VIII-8) My:

In the formula, R ⁴ is alkylene having 6 to 20 carbon atoms; R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene;

Wherein A ¹ , A ² , A ³ and A ⁴ are independently cyclohexylene or phenylene; X ³ and X ⁴ are independently a single bond, alkylene having 1 to 5 carbon atoms, or —O—; X ⁵ and X ⁶ are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ —, —O— or —S—; Y ¹ is -CH _2- , -C (R ¹¹ ) (R ¹² )-, -CO- or -SO _2- , and R ¹¹ and R ¹² are independently hydrogen, alkyl having 1 to 12 carbons, or 1 carbon -12 alkyl fluorides; m1, m2, m3, m4 and n independently represent 0 or 1, and in the cyclohexylene and phenylene, any hydrogen may be substituted with alkyl or benzyl having 1 to 4 carbon atoms, and a bond of these substituents The position is arbitrary; Provided that when A ¹ , A ² , A ³ and A ⁴ are all 1,4-phenylene, then X ³ , X ⁴ , X ⁵ and X ⁶ are not all single bonds;

Wherein X ¹ and X ² are a single bond, —O—, —COO—, —OCO—, —NH—, —CONH—, or alkylene having 1 to 12 carbon atoms; G ¹ and G ² are divalent groups containing 1 to 3 rings selected from a single bond or an aromatic ring having 6 to 12 carbon atoms and an alicyclic ring having 3 to 12 carbon atoms; R ⁶ is hydrogen, fluorine, -CN, -OH, alkyl having 1 to 30 carbon atoms, fluorinated alkyl having 1 to 30 carbon atoms or alkoxy having 1 to 30 carbon atoms; When X ¹ , G ¹ , X ² and G ² are all single bonds, R ⁶ is alkyl having 3 to 30 carbon atoms, fluorinated alkyl having 3 to 30 carbon atoms or alkoxy having 3 to 30 carbon atoms, and G ² is single When R ² is neither a single bond nor alkylene, R ⁶ is hydrogen or alkyl having 3 to 30 carbon atoms, and when G ¹ and G ² are both single bonds, then X ¹ , X ² and R ⁶ The total carbon number is 3 or more;

In the formula, R ⁷ is hydrogen or alkyl having 1 to 12 carbon atoms; Ring B is 1,4-phenylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms, or 1,4-cyclohexylene, in which any hydrogen may be substituted with alkyl having 1 to 4 carbon atoms; X ⁰ is a single bond or alkylene having 1 to 5 carbon atoms, and s is an integer of 0 to 3; When s is 2 or 3, a plurality of rings B may all be the same ring, may be composed of at least two different rings, a plurality of X ⁰ may be all the same group, or may be composed of at least two different groups ; Z ¹ and Z ² are independently a single bond, —CH ₂ —, —CH ₂ CH ₂ — or —O—, and t1 and t2 are independently integers from 0 to 3; when t1 is 2 or 3, a plurality of Z1 may all be the same group and may be composed of at least two different groups; when t2 is 2 or 3, the plurality of Z2 may all be the same group and may be composed of at least two different groups;

In formula, R ⁵ may be substituted for any —CH ₂ — with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO—. Alkylene having 6 to 20 carbon atoms. The method of claim 1,
The polyamic acid reacts at least one of the diamines represented by formulas (VII-1) to (VII-3) with at least one of tetracarboxylic dianhydrides represented by formulas (VIII-7) and (VIII-8). At least one of the polyamic acid obtained by making it, or the diamine represented by Formula (VIII-1)-Formula (VIII-6) is represented by Formula (VII-4) and Formula (VII-5) at least 1 An alignment agent which is a polyamic acid obtained by reacting with:

In the formula, R4 is alkylene having 6 to 20 carbon atoms; R ⁵ is the carbon number at which any —CH ₂ — may be substituted with —O—, —NH—, —N (CH ₃ ) —, —Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ — or —COO— 6-20 alkylene;

. The liquid crystal aligning film obtained by giving anisotropy to the film | membrane obtained by apply | coating the aligning agent of Claim 1 to a board | substrate by rubbing or light irradiation, and then heating to the liquid crystal temperature range of a film | membrane, and increasing anisotropy of a film | membrane. The liquid crystal aligning film obtained by giving anisotropy to the film | membrane obtained by apply | coating the aligning agent in any one of Claims 2-9 to a board | substrate by light irradiation, and then heating to the liquid crystal temperature range of a film | membrane, and increasing anisotropy of a film | membrane. The liquid crystal aligning film obtained by providing rubbing anisotropy to the film | membrane obtained by apply | coating the aligning agent of Claim 10 to a board | substrate, and heating to the liquid crystal temperature range of a film | membrane after that, and increasing the anisotropy of a film | membrane. The liquid crystal display element which has a liquid crystal aligning film of Claim 11. The liquid crystal display element which has a liquid crystal aligning film of Claim 12. The liquid crystal display element which has a liquid crystal aligning film of Claim 13. Polyamic acid containing the structural unit represented by Formula (IX), and having a liquid crystal temperature range in 100-300 degreeC, or its precursor:

In the formula, R ⁵ is alkylene having 6 to 12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), A residue of any one of diamines represented by formulas (V-1) and (VI-1) to (VI-7);

. Polyamic acid containing the structural unit represented by Formula (X), and having a liquid crystal temperature range in 100-300 degreeC, or its precursor:

In the formula, R ⁵ is alkylene having 6 to 12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), A residue of any one of diamines represented by formulas (V-1) and (VI-1) to (VI-7);

. 18. The method of claim 17,
The polyamic acid which is polyimide or its precursor whose R <^9> is the residue of any of the diamine represented by Formula (VIII-1)-Formula (VIII-6):

. 19. The method of claim 18,
The polyamic acid which is polyimide or its precursor whose R <^9> is the residue of any of the diamine represented by Formula (VIII-1)-Formula (VIII-6):

. Polyamic acid which is a polyimide or its precursor which contains a structural unit represented by Formula (IX) and a structural unit represented by Formula (XI), and has a liquid crystal temperature range in 100-300 degreeC:

In which R ⁵ is alkylene having 6-12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), A residue of any one of diamines represented by formula (V-1) and formula (VI-1) to formula (VI-7); R ¹⁰ is a residue of any of the diamines represented by formulas (VIII-1) to (VIII-6):

. Polyamic acid which is a polyimide or its precursor which contains the structural unit represented by Formula (X) and the structural unit represented by Formula (XII), and has a liquid crystal temperature range in 100-300 degreeC:

In which R ⁵ is alkylene having 6-12 carbon atoms; R ⁹ is formula (I-1) to formula (I-3), formula (II-1) to formula (II-3), formula (III-1), formula (IV-1) to formula (IV-3) ), A residue of any one of diamines represented by formula (V-1) and formula (VI-1) to formula (VI-7); R ¹⁰ is a residue of any of the diamines represented by formulas (VIII-1) to (VIII-6):

.