KR20110063295A - Liquid crystal aligning agent and liquid crystal display device - Google Patents

Abstract

PURPOSE: A liquid crystal alignment agent is provided to reduce light transmittance at a dark state in an electric field non-authorization while exhibiting favorable effect of an in-plane switching type liquid crystal display device, and to form a liquid crystal alignment film having excellent afterimage property. CONSTITUTION: A liquid crystal alignment agent includes at least one kind of a polymer selected from the group consisting of polyamic acid and polyimide, wherein the polymer has chemical formulas (1) and (2) in at least a part within the material. In chemical formula (1), R^1 is C1~6 alkyl group; R^2 is C1~6 alkyl group, halogen, cyano, hydroxyl or carboxy; n is an integer of 1~10; a is an integer of 0~4; * is dangling bonds. In chemical formula (2), R^3 is C1~6 alkyl group; R^4 is C1~6 alkyl group, halogen, cyano, hydroxyl or carboxy; b is an integer of 1 0~5; c is an integer of 0~4; d is an integer of 0~3; and * is dangling bonds.

Description

Liquid crystal aligning agent and liquid crystal display element {LIQUID CRYSTAL ALIGNING AGENT AND LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More specifically, the liquid crystal aligning agent which gives the liquid crystal display element excellent in the dark state display at the time of no field application, especially when it is applied to the liquid crystal display element of a lateral field display type, and such a liquid crystal A display element is related.

An electrode is formed on only one side of a pair of opposed substrates, and an electric field is generated in a direction parallel to the substrate, for example, in an in-plane switching (IPS) mode or in a fringe field switching (FFS) mode. The liquid crystal display element has a wider viewing angle characteristic and has a higher quality display than the conventional longitudinal electric field type liquid crystal display element in which electrodes are formed on both substrates to generate an electric field in a direction perpendicular to the substrate. It is known that this is possible. Such transverse electric field display mode liquid crystal display elements are described, for example in Patent Documents 1 and 2 and Non-Patent Document 1. Since the transverse electric field type liquid crystal display element responds to the electric field only in the direction parallel to the substrate, the change in the refractive index of the long axis direction of the liquid crystal molecules does not become a problem, and even if the view is changed, the viewer is visually recognized. (Iii) The change in contrast and the color of the display color is small, and thus high quality display is possible regardless of the time of day.

In this transverse electric field type liquid crystal display element, the dark state-bright state at the time of the electric field unapplied-applied switching of an element for the purpose of further improving display performance and reducing the power consumption by raising the utilization efficiency of a backlight further. There is a demand for a liquid crystal display device having a large ratio (contrast) of a transmittance of.

Here, in the transverse electric field type liquid crystal display element which has the liquid crystal layer of anti-parallel orientation state between the two polarizing plates arrange | positioned cross nicol, in the dark state at the time of no electric field application, the orientation axis of a liquid crystal is The second polarizing plate in which linearly polarized light passing through the liquid crystal layer passes through the liquid crystal layer without disturbing its phase when coinciding with the polarization axis of the first polarizing plate, and the passing light is arranged in parallel with the first polarizing plate. The black display can be secured by being blocked. At this time, when the alignment of the liquid crystal does not coincide with the polarization axis of the polarizing plate, the linearly polarized light passing through the liquid crystal layer becomes circularly polarized light (or elliptical polarization), and a part thereof passes through the second polarizing plate, causing light leakage. Let's go.

Therefore, the development of the liquid crystal aligning film which achieves the uniaxial orientation of a liquid crystal highly has become abrupt. In the past studies, attempts have been made to improve the uniaxial orientation of liquid crystal molecules by using polyimide synthesized from aromatic tetracarboxylic dianhydride and aromatic diamine (Non-Patent Document 2). However, by this technique, satisfactory results are not obtained for the improvement of the dark state at the time of no electric field.

Moreover, in a transverse electric field type liquid crystal display element, afterimage and burn-in may become a problem, and the improvement is calculated | required. In this respect, in Patent Document 6, a method of improving the afterimage characteristic and the burn-in characteristic is proposed by using the liquid crystal aligning film which consists of a polymer containing an aromatic structure in a large ratio. However, when a liquid crystal aligning film containing a large proportion of the aromatic structure is used, the pretilt angle inevitably increases, and the above advantageous effects in the transverse electric field type display element are attenuated.

In the transverse electric field type liquid crystal display element, the liquid crystal display element which can fully express said advantageous effect, and gives the liquid crystal aligning film which shows the improved afterimage characteristic and burn-in characteristic is not known yet, The provision of such a liquid crystal aligning agent is provided. This is strongly desired.

US Patent No. 5928733 Japanese Laid-Open Patent Publication No. 56-91277 Japanese Patent Laid-Open No. 6-222366 Japanese Patent Application Laid-open No. Hei 6-281937 Japanese Patent Application Laid-Open No. 5-107544 Japanese Laid-Open Patent Publication No. 2008-15497 Japanese Laid-Open Patent Publication No. 2010-97188

 "Liq. Cryst.", Vol. 22, p 379 (1996)  "Functional material", vol. 27, p69 (2007)

This invention is made | formed in view of the said situation, The objective is to exhibit the advantageous effect of a transverse electric field type liquid crystal display element effectively, to reduce the light transmittance in the dark state at the time of no electric field application, and also to provide excellent afterimage. It is providing the liquid crystal aligning agent which gives the liquid crystal aligning film which has a characteristic, and a liquid crystal display element with large contrast.

Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above object of the present invention, firstly,

At least one polymer selected from the group consisting of polyamic acid and polyimide, provided that at least part of the polymer has a structure represented by each of the following formulas (1) and (2): It is achieved by the liquid crystal aligning agent characterized by the above-mentioned.

[In Formula (1), R <^1> is respectively independently a C1-C6 alkyl group, R <^2> is each independently a C1-C6 alkyl group, a halogen atom, a cyano group, a hydroxyl group, or a carboxyl group, n is An integer of 1 to 10, a each independently represents an integer of 0 to 4, and "*" represents a bond;

In formula (2), R <^3> is a C1-C6 alkyl group, R <^4> is respectively independently a C1-C6 alkyl group, a halogen atom, a cyano group, a hydroxyl group, or a carboxyl group, b is an integer of 0-5 C is an integer of 0 to 4, d is an integer of 0 to 3, and "*" represents a bond.

The above object of the present invention, secondly,

It is achieved by the liquid crystal display element provided with the liquid crystal aligning film formed from said liquid crystal aligning agent.

While the liquid crystal aligning agent of this invention exhibits the advantageous effect of a transverse electric field type liquid crystal display element effectively, the light transmittance in the dark state at the time of no electric field is reduced, and can also form the liquid crystal aligning film which has the outstanding afterimage characteristic. Can be. The liquid crystal display element of this invention provided with the liquid crystal aligning film formed from such a liquid crystal aligning agent of this invention is large in contrast, and is excellent in an afterimage characteristic.

Therefore, although the liquid crystal aligning agent of this invention is used suitably in order to form the liquid crystal aligning film of a transverse electric field type liquid crystal display element, it is also suitable also for other various liquid crystal display elements, such as TN type, STN type, and VA type.

Such a liquid crystal display element of the present invention can be effectively applied to various devices, and for example, a clock, a portable game, a word processor, a notebook personal computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, It can use for display apparatuses, such as various monitors and a liquid crystal television.

BRIEF DESCRIPTION OF THE DRAWINGS It is schematic which shows the structure of the two system transparent conductive film pattern which the liquid crystal display element manufactured for evaluation of the afterimage characteristic in an Example and a comparative example has.

(Form to carry out invention)

Hereinafter, the present invention will be described in detail.

The liquid crystal aligning agent of this invention is at least 1 sort (s) of polymer chosen from the group which consists of a polyamic acid and a polyimide, provided that the said polymer is represented by each of said Formula (1) and (2) in at least one part in the molecule | numerator. Having together). In this specification, such a polymer is called "specific polymer" hereafter. In this specific polymer, the structure represented by said formula (1) may exist in the main chain of a polymer, may exist in the side chain of a polymer, or may exist in both the main chain and side chain of a polymer;

The structure represented by said formula (2) may exist in the main chain of a polymer, may exist in the side chain of a polymer, or may exist in both the main chain and side chain of a polymer.

As R <^1> in said formula (1), it is preferable that it is a C1-C3 alkyl group, and it is especially preferable that it is a methyl group. As a C1-C6 alkyl group of R <^2> , it is preferable that it is a C1-C3 alkyl group, respectively, and it is especially preferable that it is a methyl group. It is preferable that each a is 0. It is preferable that it is 1-4, and, as for n, it is more preferable that it is 2-4.

As R <^3> in said Formula (2), it is preferable that it is a C1-C3 alkyl group, and it is especially preferable that it is a methyl group. As a C1-C6 alkyl group of R <^2> , it is preferable that it is a C1-C3 alkyl group, respectively, and it is especially preferable that it is a methyl group. It is preferable that b is an integer of 1-5, It is more preferable that it is 3, It is especially preferable that b is 3 and it is preferable that the substitution position of three groups R <^3> is in the 1,3,3-position of a phosphorus ring. It is preferred that c and d are each 0 (optionally having the group R ⁴ ). It is preferable that the phenylene group couple | bonds with the 1-position of a phosphorus monocycle.

It is preferable that the specific polymer in this invention contains the structure represented by said Formula (1) in 0.001-0.002 mol / g range;

It is preferable to contain the structure represented by said formula (2) in 0.0002 to 0.001 mol / g.

Polyamic acid having a structure represented by each of the above formulas (1) and (2) in at least part of the molecule is, for example

Tetracarboxylic dianhydride containing both the structure represented by said formula (1) and the compound which has two carbonic anhydride groups, and the compound represented by said formula (2) and two carbonic anhydride groups, and a diamine family React, or

It can be obtained by reacting tetracarboxylic dianhydride with a diamine containing both a structure represented by the formula (1) and a compound having two amino groups and a structure represented by the formula (2) and a compound having two amino groups. There is,

The polyimide which has the structure represented by each of said Formula (1) and (2) together in at least one part in a molecule | numerator can be obtained by dehydrating and ring-closing the polyamic acid obtained by the above, for example.

As a specific polymer contained in the liquid crystal aligning agent of this invention, it has tetracarboxylic dianhydride, the structure represented by said formula (1), the compound which has two amino groups, and the structure represented by said formula (2), and two amino groups. It is preferable that it is at least 1 sort (s) of polymer chosen from the group which consists of the polyamic acid obtained by making it react with diamine containing both of a compound, and the polyimide formed by dehydrating and closing the said polyamic acid.

<Polyamic acid>

As mentioned above, the preferable polyamic acid in this invention is tetracarboxylic dianhydride, the compound represented by said Formula (1), the compound which has two amino groups, and the structure represented by said Formula (2), and two amino groups. It is obtained by making it react with the diamine containing both of the compound which has.

[Tetracarboxylic dianhydride]

Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention include aromatic tetracarboxylic dianhydride, tetracarboxylic dianhydride and alicyclic dicarboxylic anhydride structures having an aliphatic dicarboxylic anhydride structure. The tetracarboxylic dianhydride which has both a tetracarboxylic dianhydride which has, an aliphatic dicarboxylic anhydride structure, and an aromatic dicarboxylic acid anhydride structure, etc. are mentioned. Here, as tetracarboxylic dianhydride which has an aliphatic dicarboxylic acid anhydride structure, Aliphatic tetracarboxylic dianhydride etc .;

As tetracarboxylic dianhydride which has alicyclic dicarboxylic anhydride structure, alicyclic tetracarboxylic dianhydride etc. are mentioned, respectively.

As said aromatic tetracarboxylic dianhydride, a pyromellitic dianhydride, a following formula (T-1):

[In formula (T-1), R <^5> is respectively independently a C1-C6 alkyl group, a halogen atom, a cyano group, or a hydroxyl group, e is each independently an integer of 0-3.]

The compound etc. which are represented by are mentioned. As a C1-C6 alkyl group of R <^5> in said Formula (T-1), it is preferable that it is a C1-C3 alkyl group, respectively, and it is especially preferable that it is a methyl group. It is preferable that e is 0, respectively. As a specific example of a compound represented by said Formula (T-1), 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride, 2,2', 3,3'-biphenyl tetracarboxylic acid, for example. 2 anhydrides, etc. are mentioned.

As said aliphatic tetracarboxylic dianhydride, butane tetracarboxylic dianhydride etc. are mentioned, for example. As tetracarboxylic dianhydride which has both the said aliphatic dicarboxylic acid anhydride structure and aromatic dicarboxylic acid anhydride structure, it is following formula (T-2):

[In formula (T-2), R <^6> and R <^7> is respectively independently a C1-C6 alkyl group, a halogen atom, a cyano group, or a hydroxyl group, f is an integer of 0-8, g is 0 or 1 ]

The compound etc. which are represented by are mentioned. As a C1-C6 alkyl group of R <^6> and R <^7> in said Formula (T-2), it is preferable that it is a C1-C3 alkyl group, respectively, and it is especially preferable that it is a methyl group. f and g are each preferably 0. As a specific example of a compound represented by said formula (T-2), it is 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl), for example. Naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] furan-1,3-dione etc. are mentioned.

Examples of the alicyclic tetracarboxylic dianhydride include, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride, and 3-oxabicyclo [3.2]. .1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl)- 3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride, 2,4,6 , 8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-2 anhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8, 10-tetraone etc. are mentioned, respectively. In addition to the above, as the tetracarboxylic dianhydride for synthesizing the polyamic acid in the present invention, tetracarboxylic dianhydride described in Patent Document 7 (Japanese Patent Laid-Open No. 2010-97188) can be used, and 1 is selected from these. More than one species can be used.

Here, among tetracarboxylic dianhydrides having an aliphatic dicarboxylic acid anhydride structure, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 2,3,5-tricarboxycyclopentyl acetic dianhydride are Can be mentioned.

As tetracarboxylic dianhydride used in order to synthesize the polyamic acid in this invention,

At least one selected from aromatic tetracarboxylic dianhydrides;

Selected from tetracarboxylic dianhydrides with aliphatic dicarboxylic anhydride structures, tetracarboxylic dianhydrides with alicyclic dicarboxylic acid anhydride structures, and tetracarboxylic dianhydrides with both aliphatic dicarboxylic acid anhydride structures and aromatic dicarboxylic anhydride structures It is preferable that it contains at least 1 sort (s). At this time, the preferable use ratio, more preferable use ratio, and more preferable use ratio with respect to the total tetracarboxylic dianhydride of each said tetracarboxylic dianhydride are as follows, respectively.

By using the mixture of tetracarboxylic dianhydride of the ratio similar to the said table, it becomes clear to form the liquid crystal aligning film which is more excellent in liquid crystal aligning performance, and it is preferable.

As tetracarboxylic dianhydride used for synthesize | combining the polyamic acid in this invention, At least 1 sort (s) chosen from aromatic tetracarboxylic dianhydride within the said range,

Selected from tetracarboxylic dianhydrides with aliphatic dicarboxylic anhydride structures, tetracarboxylic dianhydrides with alicyclic dicarboxylic acid anhydride structures, and tetracarboxylic dianhydrides with both aliphatic dicarboxylic acid anhydride structures and aromatic dicarboxylic anhydride structures It is most preferable to use what consists of at least 1 sort (s) and which does not contain other tetracarboxylic dianhydride.

[Diamine]

The diamine used for synthesizing the preferred polyamic acid in the present invention is a compound having a structure represented by the formula (1) and two amino groups, and a compound represented by the formula (2) and a compound having two amino groups. It will include.

As a preferable example of the compound which has a structure represented by said Formula (1), and two amino groups, the compound etc. which are represented by following formula (D-1) are mentioned, for example;

As a preferable example of the compound which has a structure represented by said formula (2), and two amino groups, the compound etc. which are represented by following formula (D-2) are mentioned, for example.

[R <^1> , R <^2> , n and a in Formula (D-1) are the same meaning as the thing in said Formula (1), respectively;

R <^3> , R <^4> , b, c, and d in Formula (D-2) are the same meaning as the thing in said Formula (2), respectively.]

As a compound represented by said Formula (D-1), it is 2, 2-bis- (4-aminophenyl) propane, 2, 2-bis- (3-aminophenyl) propane, 4,4'-, for example. [1,3-phenylenebis (1-methylethylidene)] bisaniline, 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline, etc. are mentioned, Of these, 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisaniline is particularly preferable.

As a compound represented by said formula (D-2), it is 1- (4-aminophenyl) -1,3,3-trimethyl-1H-indan-5-amine, 1- (4-aminophenyl) -1, for example. , 3,3-trimethyl-1H-indan-6-amine and the like.

As a diamine for synthesizing a preferable polyamic acid in the present invention, only the compound represented by the formula (D-1) and the compound represented by the formula (D-2) may be used, and are represented by the formula (D-1). You may use other diamine together with a compound and the compound represented by said formula (D-2).

As other diamine which can be used here, an aliphatic diamine, alicyclic diamine, aromatic diamine, diamino organosiloxane, etc. are mentioned, for example. As these specific examples, As an aliphatic diamine, For example, 1, 1- metha xylylenediamine, 1, 3- propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, etc .;

As alicyclic diamine, For example, 1, 4- diamino cyclohexane, 4, 4'- methylenebis (cyclohexylamine), 1, 3-bis (aminomethyl) cyclohexane, etc .;

As aromatic diamine, for example, p-phenylenediamine, 4,4'- diaminodiphenylmethane, 4,4'- diaminodiphenyl sulfide, 1,5- diaminonaphthalene, 2,2'-dimethyl -4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4'-diamino Diphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy Phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m- Phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4 -Diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3 , 6-diaminocarbazole, N-phenyl-3,6-di Aminocarbazole, N, N'-bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, 1,4-bis- (4-amino Phenyl) -piperazine, 3,5-diaminobenzoic acid, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-dia Minobenzene, cholesteryloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-diaminobenzoic acid ranostanyl, 3, 6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4'-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diamino Benzoate, 4- (4'-trifluoromethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclo Hexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4- Butyl cyclohexane, 1,1-bis (4 - ((amino) methyl) phenyl) -4- (4-heptyl cyclohexyl) cyclohexane, and the following formula (D-3):

[In formula (D-3), X <^I> is a C1-C3 alkylene group, ^* -O-, ^* -COO-, or ^* -OCO- (However, the bond which added "*" couple | bonds with a diaminophenyl group. M1 is 0 or 1, m2 is an integer of 0 to 2, and h is an integer of 1 to 20.

Compounds represented by these;

Examples of the diaminoorganosiloxanes include 3,3 '-(tetramethyldisiloxane-1,3-diyl) bis (propylamine) and the like, respectively.

The diamine described in patent document 7 (Unexamined-Japanese-Patent No. 2010-97188) can be used.

X ^I in the formula (D-3) is preferably an alkyl group having 1 to 3 carbon atoms, ^* -O- or ^* -COO-, provided that the bond to which "*" is attached is combined with a diaminophenyl group. Do. Specific examples of the group C _h H _{2h +} 1- include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and n. -Nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, etc. are mentioned. It is preferable that two amino groups in a diaminophenyl group exist in 2, 4-position or 3, 5-position with respect to another group.

As a specific example of a compound represented by said formula (D-3), For example, dodecaneoxy-2,4-diaminobenzene, tetradecaneoxy-2,4-diaminobenzene, pentadecaneoxy-2,4-dia Minobenzene, hexadecaneoxy-2,4-diaminobenzene, octadecaneoxy-2,4-diaminobenzene, dodecaneoxy-2,5-diaminobenzene, tetradecaneoxy-2,5-diaminobenzene , Pentadecaneoxy-2,5-diaminobenzene, hexadecaneoxy-2,5-diaminobenzene, octadecaneoxy-2,5-diaminobenzene, the following formulas (D-3-1) to (D- 3-3):

The compound etc. which are represented by each of these are mentioned. The liquid crystal aligning agent containing at least 1 sort (s) of polymer chosen from the group which consists of polyamic acid and polyimide obtained using the diamine containing the compound represented by said formula (D-3) is a liquid crystal aligning agent of a vertical alignment type. It can be used very suitably.

In said Formula (D-3), it is preferable that m1 and m2 do not become zero simultaneously.

As other diamine, p-phenylenediamine, 3, 5- diamino benzoic acid, 4,4'- diamino diphenylmethane, 4,4'- diamino diphenyl ether, and 3,3'- ( It is preferable to use at least 1 sort (s) chosen from the group which consists of tetramethyl disiloxane-1, 3- diyl) bis (propylamine).

The diamine used to synthesize the polyamic acid in the present invention,

It is preferable that the compound represented by said formula (D-1) contains 50-90 mol% with respect to all diamine;

It is preferable that the compound represented by said formula (D-2) contains 10-50 mol% with respect to all diamine;

Said other diamine can be contained in 40 mol% or less with respect to all diamine.

[Synthesis of Polyamic Acid]

The polyamic acid in the present invention is made by reacting a tetracarboxylic acid dianhydride as described above with a diamine containing both a compound represented by Formula (D-1) and a compound represented by Formula (D-2). You can get it.

The use ratio of tetracarboxylic dianhydride and diamine provided in the polyamic acid synthesis reaction is preferably such that the acid anhydride group of tetracarboxylic dianhydride is 0.2 to 2 equivalents to 1 equivalent of the amino group of the diamine. More preferably, it is a ratio which becomes 0.7-1.2 equivalent.

The synthesis reaction of the polyamic acid is preferably in an organic solvent, preferably -20 ° C to 150 ° C, more preferably under a temperature condition of 0 to 100 ° C, preferably 1 to 72 hours, more preferably Is performed for 3 to 48 hours. The organic solvent is not particularly limited as long as it can dissolve the polyamic acid to be produced. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide , Amide compounds such as 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, dimethyl sulfoxide, γ Non-protic compounds such as butyrolactone, tetramethylurea and hexamethylphosphotriamide;

Phenolic compounds, such as m-cresol, a xylenol, a phenol, a halogenated phenol, etc. can be illustrated. As for the usage-amount of an organic solvent ((alpha: when using a poor solvent mentioned later) together, the total usage-amount of an organic solvent and the said poor solvent), the total amount (beta) of tetracarboxylic dianhydride and diamine, The amount is preferably 0.1 to 30% by weight based on the total amount of the reaction solution (α + β).

In the organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like, which are generally believed to be poor solvents of polyamic acid, may be used together in a range in which polyamic acid to be produced is not precipitated. Specific examples of such poor solvents include methanol, ethanol, isopropanol, cyclohexanol, 4-hydroxy-4-methyl-2-heptanone, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, Ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, Diethyl oxalate, diethyl malonic acid, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl Ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl Ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, Chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, diisobutyl ketone, isoamyl propionate, isoamyl isobutylate, diisopentyl ether and the like.

When using together an organic solvent and the said poor solvent, the usage-amount of the said poor solvent can be suitably set in the range which does not precipitate the polyamic acid produced, It is preferable that it is 30 weight% or less with respect to the total amount of a solvent, 20 It is more preferable that it is weight% or less.

This reaction solution may be used as it is for preparation of a liquid crystal aligning agent, may be provided to preparation of a liquid crystal aligning agent after isolating the polyamic acid contained in a reaction solution, or after refine | purifying the isolated polyamic acid, preparation of a liquid crystal aligning agent You may provide to. When polyamic acid is dehydrated and closed, and it is set as polyimide, the said reaction solution may be used for a dehydration ring-closure reaction as it is, may be used for dehydration ring-closure reaction after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid After purification, the dehydration ring-closure reaction may be used. Isolation of polyamic acid can be performed by pouring the said reaction solution in a large amount of poor solvents, obtaining a precipitate, and drying this precipitate under reduced pressure, or distilling off the organic solvent in a reaction solution with an evaporator under reduced pressure. have. Further, the polyamic acid is dissolved in an organic solvent again, and then precipitated with a poor solvent, or after washing the solution obtained by dissolving polyamic acid in an organic solvent again, the organic solvent contained in the washed solution is evaporated. Polyamic acid can be refine | purified by the method of carrying out the process of distilling under reduced pressure with a gas generator once or several times.

<Polyimide>

The polyimide as a specific polymer which can be contained in the liquid crystal aligning agent of this invention can be obtained by dehydrating and ring-closing such polyamic acid.

As tetracarboxylic dianhydride used for the synthesis | combination of the said polyimide, the same compound as tetracarboxylic dianhydride used for the synthesis | combination of said polyamic acid is mentioned, The tetracarboxylic acid used for the synthesis | combination of polyamic acid is also preferable. 2 The same as in the case of anhydride.

As a diamine used in order to synthesize | combine the polyimide contained in the liquid crystal aligning agent of this invention, the diamine same as the diamine used for the synthesis | combination of said polyamic acid is mentioned.

The polyimide in the present invention may be a complete imide obtained by dehydrating and ring-closing all of the dark acid structures possessed by the polyamic acid as a raw material. It may be a dehydrate. It is preferable that the imidation ratio is 40 mol% or more, and, as for the polyimide in this invention, it is more preferable that it is 80 mol% or more. By using polyimide whose imidation ratio is 40 mol% or more, the liquid crystal aligning agent which can form the liquid crystal aligning film which gives the liquid crystal display element which shows higher contrast can be obtained.

The said imidation ratio shows the ratio which the number of the number of the imide ring structures to the sum of the number of the dark acid structures of a polyimide, and the number of imide ring structures occupies as a percentage. At this time, a part of the imide ring may be an isoimide ring. The imidation ratio was obtained by dissolving polyimide in a suitable deuterated solvent (for example, deuterated dimethyl sulfoxide) and measuring ¹ H-NMR at room temperature (for example, 25 ° C) using tetramethylsilane as a reference substance. From the result, it can obtain | require by following formula (1).

Imidation ratio (%) = (1-A ¹ / A ² × α) × 100 (1)

(In Formula (1), A <^1> is the peak area derived from the proton of the NH group represented by 10 ppm of chemical shifts, A <^2> is the peak area derived from other protons, and (alpha) is a precursor (polyamic acid) of a polyimide. It is number ratio of other protons to one proton of NH group of

The dehydration ring closure of the polyamic acid is preferably heated by (i) a method of heating the polyamic acid, or (ii) the polyamic acid is dissolved in an organic solvent, and a dehydrating agent and a dehydration ring closure catalyst are added to the solution, if necessary. It is done by the method.

Reaction temperature in the method of heating the polyamic acid of said (i) becomes like this. Preferably it is 50-200 degreeC, More preferably, it is 60-170 degreeC. The reaction time is preferably 1 to 8 hours, more preferably 3 to 5 hours. When reaction temperature is less than 50 degreeC, dehydration ring-closure reaction does not fully advance, but when reaction temperature exceeds 200 degreeC, the molecular weight of the polyimide obtained may fall.

On the other hand, in the method of adding a dehydrating agent and a dehydrating ring-closure catalyst to the solution of the polyamic acid of said (ii), acid anhydrides, such as acetic anhydride, a propionic anhydride, a trifluoroacetic anhydride, can be used as a dehydrating agent, for example. Although the usage-amount of a dehydrating agent is based on a desired imidation ratio, it is preferable to set it as 0.01-20 mol with respect to 1 mol of the dark acid structure of polyamic acid. As the dehydration ring closure catalyst, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used, for example. However, it is not limited to these. It is preferable that the usage-amount of a dehydration ring-closure catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents used. The imidation ratio can be increased as the usage-amount of said dehydrating agent and dehydrating ring closure agent increases. As an organic solvent used for a dehydration ring-closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid is mentioned. The reaction temperature of the dehydration ring-closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1 to 8 hours, more preferably 3 to 5 hours.

In the method (ii), the reaction solution containing a polyimide is obtained as mentioned above. This reaction solution may be provided as it is to preparation of a liquid crystal aligning agent as it is, may be provided to preparation of a liquid crystal aligning agent after removing a dehydrating agent and a dehydration ring-closure catalyst from a reaction solution, and after isolation of a polyimide to preparation of a liquid crystal aligning agent You may provide, or after refine | purifying an isolated polyimide, you may provide for preparation of a liquid crystal aligning agent. In order to remove a dehydrating agent and a dehydration ring-closure catalyst from a reaction solution, methods, such as solvent substitution, can be applied, for example. Isolation and purification of a polyimide can be performed by performing the same operation as the above as an isolation | purification and purification method of polyamic acid.

[Terminal Modified Polymer]

The polyamic acid and the polyimide in the present invention may be polymers of terminal modified form in which the molecular weight is controlled, respectively. By using the polymer of terminal modification type, the application | coating characteristic of a liquid crystal aligning agent, etc. can further be improved, without the effect of this invention being impaired. Such terminal-modified polymer can be performed by adding a molecular weight modifier to the polymerization reaction system when synthesizing the polyamic acid. As a molecular weight modifier, an acid monoanhydride, a monoamine compound, a monoisocyanate compound, etc. are mentioned, for example.

As said acid monoanhydride, maleic anhydride, a phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n- tetradecyl succinic anhydride, n-hexadecyl succinic anhydride, etc. are mentioned, for example. have. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n- Eicosylamine, etc. are mentioned. As said monoisocyanate compound, phenyl isocyanate, naphthyl isocyanate, etc. are mentioned, for example.

The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less based on 100 parts by weight of the total amount of tetracarboxylic dianhydride and diamine used when synthesizing the polyamic acid.

[Solution viscosity]

When the polyamic acid and polyimide obtained as mentioned above are each made into the solution of 10 weight% of concentration, it is preferable that it has a solution viscosity of 20-800 mPa * s, and has a solution viscosity of 30-500 mPa * s. It is more preferable that is.

The solution viscosity (mPa * s) of the said polymer is the value measured at 25 degreeC using the E-type rotational viscometer with respect to the polymer solution of 10 weight% of concentration prepared using the positive solvent of the said polymer.

<Other additives>

Although the liquid crystal aligning film of this invention contains as an essential component the specific polymer which is at least 1 sort (s) chosen from the group which consists of said polyamic acid and polyimide formed by dehydrating and ring-closing this as an essential component, it may contain other components as needed. As such other components, other polymers, an adhesion improving agent, etc. are mentioned, for example.

The other polymers can be used for improving solution properties and electrical properties. Such other polymers are polymers other than a specific polymer, for example

Tetracarboxylic dianhydride

Polyamic acid (henceforth "other polyamic acid") obtained by making the compound represented by said formula (D-1) and the diamine which does not contain at least one of the compound represented by said formula (D-2) react with Polyimide formed by dehydrating and ringing polyamic acid (hereinafter referred to as "other polyimide"), polyamic acid ester, polyester, polyamide, polysiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) Derivatives, poly (meth) acrylates, and the like. Among these, other polyamic acid or other polyimide is preferable, and it is more preferable to use other polyamic acid.

The use ratio of the other polymer is preferably 90% by weight or less, more preferably 85% by weight or less, based on the total amount of the polymer (total of the specific polymer and other polymers, hereinafter the same). can do. When the liquid crystal aligning agent of this invention contains another polymer, it is preferable to set it as 30 weight% or more with respect to the sum total of a polymer from a viewpoint of the electrical property of the liquid crystal aligning film formed, and 50 weight% or more It is more preferable to set it as.

The said adhesive improving agent can be used for the purpose of improving the adhesiveness with respect to the board | substrate surface of the liquid crystal aligning film obtained. As such an adhesion improving agent, the compound which has at least 1 epoxy group in a molecule | numerator (henceforth "epoxy compound"), a functional silane compound, etc. are mentioned, for example.

As such an epoxy compound, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, Neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5, 6-tetraglycidyl-2,4-hexanediol, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylamino Methyl) cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane And 3- (N, N-diglycidyl) aminopropyltrimethoxysilane.

As a usage ratio of such an epoxy compound, Preferably it is 40 weight part or less with respect to 100 weight part of total amounts of a polymer, More preferably, it is 0.1-30 weight part.

As said functional silane compound, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 2-aminopropyl trimethoxysilane, 2-aminopropyl triethoxysilane, N- (2 -Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy Silane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimeth Methoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecan, 10-triethoxysilyl-1,4,7-triazadecan, 9-trimethoxysilyl-3 , 6-diazanyl acetate, 9-triethoxysilyl-3,6-diazanyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-amino Lofiltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N -Bis (oxyethylene) -3-aminopropyltriethoxysilane, etc. are mentioned.

As a usage ratio of the above functional silane compound, Preferably it is 2 weight part or less with respect to 100 weight part of total amounts of a polymer, More preferably, it is 0.01-0.2 weight part.

At least 1 sort (s) chosen from the group which consists of said polyamic acid and polyimide, and the other additive arbitrarily mix | blended as needed, Preferably the liquid crystal aligning agent of this invention is comprised, melt-containing in an organic solvent.

As an organic solvent which can be used for the liquid crystal aligning agent of this invention, for example, N-methyl- 2-pyrrolidone, (gamma) -butyrolactone, (gamma) -butyrolactam, N, N- dimethylformamide, N, N -Dimethyl acetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol methyl ether, Ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl Ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate There may be mentioned 3-butoxy -N, N- dimethylpropanamide, 3-methoxy -N, N- dimethylpropanamide, 3-hexyloxy -N, N- dimethylpropanamide.

Solid content concentration (the ratio which the total weight of components other than the solvent of a liquid crystal aligning agent occupies for the total weight of a liquid crystal aligning agent) in the liquid crystal aligning agent of this invention is selected suitably in consideration of viscosity, volatility, etc., Preferably It is the range of 1-10 weight%. That is, the liquid crystal aligning agent of this invention is apply | coated to the surface of a board | substrate as mentioned later, Preferably, the coating film used as a liquid crystal aligning film is formed by heating, but when solid content concentration is less than 1 weight%, the film thickness of this coating film is too small. It becomes difficult to obtain a favorable liquid crystal aligning film, and when solid content concentration exceeds 10 weight%, the film thickness of a coating film becomes excessive and it is difficult to obtain a favorable liquid crystal aligning film, and the viscosity of a liquid crystal aligning agent increases, and it is inferior to coating property. do.

The range of especially preferable solid content concentration changes with the method used when apply | coating a liquid crystal aligning agent to a board | substrate. For example, in the case of a spinner method, the range of 1.5 to 4.5 weight% is especially preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and the solution viscosity is in the range of 12 to 50 mPa · s. When using the inkjet method, it is especially preferable to make solid content concentration into the range of 1 to 5 weight%, and to make solution viscosity into the range of 3-15 mPa * s.

The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0 degreeC-200 degreeC, More preferably, it is 20 degreeC-60 degreeC.

<Liquid crystal display element>

The liquid crystal display element of this invention is equipped with the liquid crystal aligning film formed from the above-mentioned liquid crystal aligning agent of this invention.

Although the preferable operation mode in the liquid crystal display element of this invention is a transverse electric field type, it is applicable also suitably to a TN type, STN type, or VA type.

The liquid crystal display element of this invention can be manufactured by the process of the following (1)-(3), for example. In the step (1), the substrate used differs depending on the desired operation mode. Processes (2) and (3) are common in each operation mode.

(1) First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, and then a coating film is formed on a board | substrate by heating a coating surface.

(1-1) When manufacturing a TN type, STN type, or VA type liquid crystal display element, two board | substrates with which the patterned transparent conductive film is formed are made into a pair, on this transparent conductive film formation surface, this invention The liquid crystal aligning agent of, is preferably coated by an offset printing method, a spin coating method, a roll coater method or an inkjet printing method, and then each coated surface is heated (preferably preheated (prebaked) and baked (post). The coating film is formed by two-step heating). Here, as a board | substrate, For example, glass, such as float glass and a soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (alicyclic olefin) can be used. As the transparent conductive film formed on one surface of the substrate, an NESA film (registered trademark of PPG Co., Ltd.) made of tin oxide (SnO ₂ ), an ITO film made of indium tin oxide (In ₂ O ₃ -SnO ₂ ), or the like can be used. It is possible to obtain a patterned transparent conductive film, for example, by forming a patternless transparent conductive film and then forming a pattern by photo etching, or by using a mask having a desired pattern when forming the transparent conductive film. can do. At the time of coating of the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound, and the like are previously added to the surface on which the coating film should be formed on the substrate surface. The pretreatment to apply may be performed.

The coating surface after a liquid crystal aligning agent application | coating is then preheated (prebaked), and further baked (postbaking) is formed. Prebaking conditions are 0.1 to 5 minutes, for example at 40-120 degreeC, and postbaking conditions are preferably 120-300 degreeC, More preferably, it is 150-250 degreeC, Preferably it is 5-200 minutes, More Preferably it is 10-100 minutes. The film thickness of the coating film formed becomes like this. Preferably it is 0.001-1 micrometer, More preferably, it is 0.005-0.5 micrometer.

(1-2) On the other hand, when manufacturing a transverse electric field type liquid crystal display element, this invention is provided in the electrically conductive film formation surface of the board | substrate in which the transparent conductive film patterned by the comb-tooth shape is formed, and the one surface of the opposing board | substrate in which the conductive film is not formed. The liquid crystal aligning agent of each is apply | coated, and then a coating film is formed by heating each application surface.

The material used for the substrate and the transparent conductive film at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film, the pretreatment of the substrate, and the preferred film thickness of the formed coating film are the same as in the above (1-1).

Also in any of said (1-1) and (1-2), although the liquid crystal aligning agent of this invention forms the coating film used as an oriented film by removing an organic solvent after application | coating, the polymer contained in the liquid crystal aligning agent of this invention is In the case of the polyimide which has a polyamic acid or an imide ring structure, and a dark acid structure, it is good also as an imidized coating film by advancing dehydration ring-closure reaction by further heating after coating film formation.

(2) When manufacturing a VA type liquid crystal display element, although the coating film formed as mentioned above can be used as a liquid crystal aligning film as it is, you may perform the rubbing process mentioned next.

On the other hand, when manufacturing a TN type, STN type, or a transverse electric field type liquid crystal display element,

The rubbing process which rubs a coating film formed as mentioned above with the roll which rolled up the cloth which consists of fibers, such as nylon, a rayon, a cotton, in a fixed direction, for example is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film.

Moreover, about the liquid crystal aligning film formed by the liquid crystal aligning agent of this invention, as shown, for example in patent document 3, patent document 4, the pretilt angle of a partial area | region of a liquid crystal aligning film by irradiating a part of liquid crystal aligning film with an ultraviolet-ray. After forming a resist film on a part of the surface of the liquid crystal aligning film as described in Patent Literature 5, and then performing a rubbing treatment in a direction different from the preceding rubbing process, a process of removing the resist film is performed, thereby forming a liquid crystal aligning film region. It is possible to improve the field of view characteristic of the liquid crystal display element obtained by having a different liquid crystal aligning ability every time.

(3) With respect to the pair of substrates on which the liquid crystal alignment film is formed as described above, the two substrates are disposed to face each other through a gap (cell gap) such that the rubbing direction of the liquid crystal alignment films of the two substrates is perpendicular or antiparallel. The peripheral portion of is bonded using a sealing agent, the liquid crystal is injected and filled into the substrate surface and the cell gap partitioned by the sealing agent, and the injection hole is sealed to form a liquid crystal cell. And a liquid crystal display element can be obtained by bonding a polarizing plate to the outer surface of a liquid crystal cell so that the polarization direction may coincide or orthogonal with the rubbing direction of the liquid crystal aligning film formed in each board | substrate.

As the sealing agent, for example, an epoxy resin or the like containing an aluminum oxide sphere as a curing agent and a spacer can be used.

Examples of the liquid crystals include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable, and for example, a sieve base liquid crystal, a cyanide liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal and an ester liquid crystal , Terphenyl-based liquid crystals, biphenylcyclohexane-based liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cuban-based liquid crystals, and the like. Furthermore, for these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate; Chiral agents such as those sold under the brand names "C-15" and "CB-15" (manufactured by Merck); You may add and use strong dielectric liquid crystals, such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate.

As a polarizing plate bonded to the outer surface of a liquid crystal cell, the polarizing plate which consists of a polarizing plate which sandwiched the polarizing film called "H film | membrane" which absorbed iodine, and extended | stretched polyvinyl alcohol by the cellulose acetate protective film, or the H film itself is mentioned. .

(Example)

Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not restrict | limited to these Examples.

In the following synthesis example, 4,4'- [1, 3- phenylene bis (1-methyl ethylidene)] bis aniline used the commercial item "bis aniline M" by Mitsui Chemical Co., Ltd. as it was. .

In addition, the solution viscosity of the polymer in each synthesis example is the value measured at 25 degreeC using the E-type viscometer.

Synthesis Example of Polymer

Synthesis Examples 1 to 7 and Comparative Synthesis Examples 1 to 3

Diamine and tetracarboxylic dianhydride in the amounts shown in Table 1 were added to N-methyl-2-pyrrolidone in this order to prepare a solution having a monomer concentration of 15% by weight, and react at room temperature for 6 hours. , Solutions containing polyamic acid (PA-1) to (PA-7) and (PAR-1) to (PAR-3) were obtained, respectively. Each solution was aliquoted a little, and the solution viscosity measured by adding N-methyl- 2-pyrrolidone as a solution of 10 weight% of polyamic acid concentration is shown in Table 1.

Each half in these polyamic acid solutions was ensured, and it used for Examples 1-6 and 12 and Comparative Examples 1-3 which follow.

Of each polyamic acid, dehydration ring-closure reaction was performed to (PA-1)-(PA-5), (PA-7), and (PAR-1) as follows, and it was set as the polyimide, respectively.

N-methyl-2-pyrrolidone was added to the remaining half of each of the polyamic acid solutions to obtain a solution having a polyamic acid concentration of 6% by weight, and pyridine and acetic anhydride were added to 1 mole of the acid acid unit each of which polyamic acid had. After adding to the molar ratio shown in Table 1, it heated at 110 degreeC and performed dehydration ring-closure reaction for 4 hours. After the dehydration ring closure reaction, the solvent in the system was substituted with fresh N-methyl-2-pyrrolidone (pyridine and acetic anhydride used in the dehydration ring closure reaction in this operation were removed from the system) to thereby remove polyimide (PI-1) to Solutions containing 15% by weight of (PI-5), (PI-7), and (PIR-1), respectively, were obtained. The imidation ratio of each polyimide and each solution contained in these polyimide solutions were fractionated, and the solution viscosity measured as the N-methyl- 2-pyrrolidone solution of 10 weight% of polyimide concentration is measured in Table 1, respectively. Indicated.

These polyimide solutions were used in subsequent Examples 7-12 and Comparative Example 4, respectively.

In addition, in Table 1, abbreviated-name of diamine and tetracarboxylic anhydride is the following meanings, respectively.

<Diamine>

d-1: 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisaniline

d-2: 1- (4-aminophenyl) -1,3,3-trimethyl-1H-indane-5-amine

d-3: p-phenylenediamine

d-4: 4,4'-diaminodiphenylmethane

d-5: 4,4'- diamino diphenyl ether

d-6: 3,3'-bis (tetramethyldisiloxane-1,3-diyl) -bis (propylamine)

d-7: 3,5-diaminobenzoic acid

<Tetracarboxylic dianhydride>

t-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride

t-2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

t-3: pyromellitic dianhydride

t-4: 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride

Example 1

<Preparation of liquid crystal aligning agent>

Γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) were added to a solution containing polyamic acid (PA-1) obtained in Synthesis Example 1, Furthermore, 10 weight parts of N, N, N ', N'- tetraglycidyl-4,4'- diamino diphenylmethane which is an epoxy compound as 100 weight part of polyamic acid (PA-1) as an adhesion improving agent In addition, the solvent ratio was made into the solution of BL: NMP: BC = 40: 40: 20 (weight ratio), and solid content concentration 4.0weight%. After fully stirring this solution, the liquid crystal aligning agent was prepared by filtering using the filter of 1 micrometer of pore diameters.

It evaluated as follows using this liquid crystal aligning agent.

<Production and Evaluation of Liquid Crystal Cells>

[Production of Liquid Crystal Cell]

The liquid crystal cell for evaluation of liquid crystal orientation and a dark state was manufactured as follows.

The above-mentioned liquid crystal aligning agent was apply | coated with the spinner on the glass substrate of thickness 1mm which has the chrome electrode formed in the comb-tooth shape on one side, and after prebaking for 1 minute on 80 degreeC hotplate, it is 230 degreeC hot It post-baked for 10 minutes on the plate, and formed the coating film of about 800 micrometers in film thickness. The rubbing process was performed with respect to the formed coating film surface using the rubbing machine which has a roll wound with the cloth made from nylon, at a roll speed of 1,000 rpm, the moving speed of 25 mm / sec of a stage, and 0.4 mm of bristle indentation lengths, The liquid crystal aligning ability was provided. Furthermore, this board | substrate was ultrasonically cleaned for 1 minute in ultrapure water, and dried for 10 minutes in a 100 degreeC clean oven, and the board | substrate which has a liquid crystal aligning film on the surface which has a comb-shaped chrome electrode was manufactured.

Separately, on one surface of a glass substrate having a thickness of 1 mm without electrodes, a coating film of a liquid crystal aligning agent is formed in the same manner as described above, subjected to a rubbing treatment, and then washed and dried to form a substrate having a liquid crystal alignment film on one surface. Manufactured.

After making these board | substrates a pair and apply | coating the aluminum oxide sphere containing epoxy resin adhesive of diameter 5.5micrometer to the outer edge of the surface which has the rubbing process liquid crystal aligning film of a board | substrate, the rubbing direction in each liquid crystal aligning film is reversed Two board | substrates were opposingly arranged through the space | interval so that it might become parallel, and the outer edge part contacted and crimped | bonded and hardened the adhesive agent. Subsequently, after filling a nematic liquid crystal (MLC-2042 by Merck Co., Ltd.) between a pair of board | substrates from a liquid crystal injection hole, the transverse type liquid crystal cell was produced by sealing a liquid crystal injection hole with an acryl-type photocuring adhesive.

[Evaluation of Liquid Crystal Cells]

(1) Evaluation of liquid crystal alignment

About the liquid crystal cell produced above, it observed using the polarization microscope. Under the present circumstances, it was evaluated that liquid crystal aligning "goodness" that light leakage was not recognized at all and only the slightest degree of light leakage was recognized as liquid crystal aligning "good" and that liquid leak was clearly recognized as liquid crystal aligning "bad". As a result, the liquid crystal orientation of this liquid crystal cell was "good."

(2) Evaluation of cancer state

The liquid crystal cell produced above was sandwiched between a pair of polarizing plates, and the degree of the dark state in the absence of voltage was investigated.

The light transmittance at the time of arranging a pair of polarizing plates and the rubbing direction of a liquid crystal aligning film and cross nicol is 0%,

When a pair of polarizing plates are set as the rubbing direction of a liquid crystal aligning film, and parallel nicol arrangement, and the light transmittance at the time of applying a voltage is made into 100%,

A pair of polarizing plates were bonded by the rubbing direction of a liquid crystal aligning film and parallel nicol arrangement | positioning, and the light transmittance in the voltage-free state was investigated. The case where the light transmittance was less than 0.1% was set as the dark state "good", and the case where it was 0.1% or more and less than 0.2% was set as the dark state "good" and 0.2% or more.

In addition, evaluation of this (2) dark state becomes "good" or "good" in the said (1) liquid crystal alignability evaluation, and evaluates precisely with higher precision about the liquid crystal cell which became once showing the very suitable liquid crystal alignability. It is evaluation which becomes an index of the display quality of the recent high quality level by performing the following.

(3) evaluation of afterimage

In the above [manufacturing of a liquid crystal cell], a substrate having a comb-tooth shaped transparent conductive film is used as a pair using a glass substrate having two lines of a comb-tooth shaped transparent conductive film pattern made of chromium and a glass substrate not having a transparent conductive film as a pair. Except having apply | coated the said liquid crystal aligning agent to the single side | surface of the electrically conductive film and the other board | substrate, respectively, it carried out similarly to the said [production of a liquid crystal cell], and manufactured the liquid crystal cell. Moreover, the liquid crystal display element was manufactured by bonding a polarizing plate to the both surfaces of the board | substrate outer side which this liquid crystal cell has, by making it into the rubbing direction of a liquid crystal aligning film, and parallel nicol arrangement.

The schematic diagram which shows the structure of the transparent electrode pattern on the said glass substrate was shown in FIG.

The above-mentioned liquid crystal display element was put in the environment of 25 degreeC and 1 atmosphere, and the combined voltage of AC voltage 3.5V and DC voltage 5V was applied to electrode A for 2 hours, without applying voltage to electrode B. Immediately thereafter, a voltage of 4 V AC was applied to both the electrode A and the electrode B. FIG. The time from the time when the voltage of the alternating current 4V was applied to both electrodes until the difference in the light transmittance between the electrodes A and B was measured. In addition, when this time is 300 seconds or less, afterimage characteristic "goodness" exceeds 300 seconds and after 500 seconds or less, it can evaluate as a residual image characteristic "good" once, but shorter this time is so preferable.

Examples 2-12 and Comparative Examples 1-4

In the said Example 1, except having used the solution containing the polymer shown in Table 2 as a polymer solution, respectively, it carried out similarly to Example 1, the liquid crystal aligning agent was prepared, and the liquid crystal cell was evaluated. In addition, in Example 12, two types were mixed and used as a polymer. Here, the adhesive improving agent used 10 weight part with respect to a total of 100 weight part of a polymer.

The evaluation results are shown in Table 2.

Claims (5)

At least one polymer selected from the group consisting of polyamic acid and polyimide, provided that at least part of the polymer has a structure represented by each of the following formulas (1) and (2): Characteristic liquid crystal aligning agent:

[In Formula (1), R <^1> is respectively independently a C1-C6 alkyl group, R <^2> is each independently a C1-C6 alkyl group, a halogen atom, a cyano group, a hydroxyl group, or a carboxyl group, n is An integer of 1 to 10, a each independently represents an integer of 0 to 4, and "*" represents a bond;
In formula (2), R <^3> is a C1-C6 alkyl group, R <^4> is respectively independently a C1-C6 alkyl group, a halogen atom, a cyano group, a hydroxyl group, or a carboxyl group, b is an integer of 0-5 C is an integer of 0 to 4, d is an integer of 0 to 3, and "*" represents a bond. The method of claim 1,
The polymer is tetracarboxylic dianhydride and
Selected from the group consisting of polyamic acid obtained by reacting a diamine containing both a compound represented by the following formula (D-1) and a compound represented by the following formula (D-2) and a polyimide formed by dehydrating and closing the polyamic acid; Liquid crystal aligning agent which is at least 1 sort (s) which becomes:

[R <^1> , R <^2> , n and a in Formula (D-1) are the same meaning as the thing in said Formula (1), respectively;
R <^3> , R <^4> , b, c, and d in Formula (D-2) are the same meaning as the thing in said Formula (2), respectively. The method of claim 2,
The tetracarboxylic dianhydride,
At least one selected from aromatic tetracarboxylic dianhydrides;
The liquid crystal aligning agent containing at least 1 sort (s) chosen from tetracarboxylic dianhydride which has an aliphatic dicarboxylic acid anhydride structure or an alicyclic dicarboxylic acid anhydride structure. The method of claim 2,
The diamine,
p-phenylenediamine, 3,5-diaminobenzoic acid, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylether and 3,3 '-(tetramethyldisiloxane-1,3 The liquid crystal aligning agent which further contains at least 1 sort (s) chosen from the group which consists of-diyl) bis (propylamine). The liquid crystal aligning film formed from the liquid crystal aligning agent in any one of Claims 1-4 is provided, The liquid crystal display element characterized by the above-mentioned.

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