TW201502202A - Liquid crystal orientation agent, liquid crystal orientation membrane, and liquid crystal display element using same - Google Patents

Abstract

Provided are a liquid crystal orientation agent which maintains an afterimage erasure time and an orientation restricting force, yet has high transparency and is less likely to cause charge storage due to asymmetrization of alternating current drive, and which contains respective polyamic acid containing a unit structure represented by one of formulas (I) and (II), and a liquid crystal orientation membrane and a liquid crystal display element using the membrane. (I) (II) (In the formulas, R1 represents a tetravalent organic group constituting aromatic-series tetracarboxylic acid; R2 represents a tetravalent organic group constituting tetracarboxylic acid; and R3 and R4 respectively represent a specific divalent organic group constituting diamine).

Description

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

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element using the liquid crystal display element which are applied by applying a parallel electric field to a substrate.

A conventional liquid crystal device is widely used as a display unit of a personal computer, a mobile phone, or a television camera. The liquid crystal device includes, for example, a liquid crystal layer sandwiched between the element substrate and the color filter substrate, a pixel electrode and a common electrode that apply an electric field to the liquid crystal layer, and an alignment film that controls the alignment of the liquid crystal molecules of the liquid crystal layer. A thin film transistor (TFT) or the like for switching an electrical signal of a pixel electrode. As the driving method of the liquid crystal molecules, a vertical electric field method such as a TN method or a VN method, or a transverse electric field method such as an IPS method or an FFS method is known. In general, a lateral electric field method in which an electrode is formed on only one side of a substrate and an electric field is applied in a direction parallel to the substrate is compared with a conventional vertical electric field method in which a voltage is applied to an electrode formed on the upper and lower substrates to drive the liquid crystal. It has a wide viewing angle characteristic and can be used as a liquid crystal display element capable of high quality display.

The liquid crystal cell of the transverse electric field mode is excellent in viewing angle characteristics, but Since the number of electrode portions formed in the substrate is small, if the voltage holding ratio of the liquid crystal alignment film is low, a sufficient voltage cannot be applied to the liquid crystal to lower the display contrast. Further, static electricity is easily accumulated in the liquid crystal cell, and the charge is accumulated in the liquid crystal cell by the application of an asymmetric voltage generated by the driving, and the accumulated electric charge may cause the alignment of the liquid crystal to be disordered or become an afterimage or The image sticking affects the display, and the display quality of the liquid crystal element is remarkably lowered. In particular, in the transverse electric field method, since the distance between the pixel electrode and the common electrode is closer than that of the vertical electric field method, a strong electric field is applied to the alignment film or the liquid crystal layer, and these disadvantages are likely to be conspicuous, which is a problem.

On the other hand, the liquid crystal alignment film is generally formed by printing a liquid crystal alignment agent, drying, and baking, and then performing a rubbing treatment. However, since the liquid crystal cell of the transverse electric field type has an electrode structure only on one side of the substrate, the unevenness of the substrate changes. A liquid crystal alignment agent which is excellent in printability as compared with the conventional alignment agent is also formed on the surface of the substrate. Further, compared with the conventional liquid crystal cell, peeling or friction cutting due to rubbing treatment is likely to occur, and such peeling and scratching may deteriorate display quality, which is a problem. Further, in the IPS (In-Plane Switching) method or the like, the alignment control force is also important in the manner in which the liquid crystal molecules aligned with the substrate are horizontally driven. If the alignment control force is weak, when the liquid crystal is driven for a long time, the liquid crystal will not return to the initial state, and the contrast will be lowered to cause the image sticking.

When a liquid crystal element is driven by such a transverse electric field, a liquid crystal alignment agent which is excellent in printability and abrasion resistance and has few afterimages or afterimages is disclosed. Patent Document 1 discloses a liquid crystal alignment agent which is derived from an aromatic four. The decyl acid unit of the carboxylic acid is copolymerized or mixed with both of the decyl unit derived from the alicyclic tetracarboxylic acid. Further, a liquid crystal alignment agent for obtaining a liquid crystal alignment film which is excellent in liquid crystal alignment property, alignment control power, and friction resistance, and has a high voltage holding ratio and which can reduce charge accumulation is disclosed in Patent Document 2, and a liquid crystal alignment agent and use thereof are disclosed. a liquid crystal display element of the liquid crystal alignment agent, which comprises a low-resistance lipopolyimide precursor having a volume resistivity of 1 × 10 ¹⁰ to 1 × 10 ¹⁴ Ωcm as a film, and having a specific A highly aligned polyimine precursor or polyimine.

However, as the performance of the liquid crystal display element is improved, the characteristics required for the liquid crystal alignment film are also severe, and it is difficult to satisfy all the required characteristics by the conventional technique.

Patent Document 1: International Publication WO02/33481

Patent Document 2: International Publication WO2004/53583

With the popularization of smart phones or tablet terminals in recent years, when such liquid crystal display elements are displayed with highly detailed images or animations such as digital photos or movies, it is expected to be equivalent to a television or a computer. High quality display performance above. For example, a mobile phone or a tablet terminal is basically driven by a battery. Therefore, from the viewpoint of saving power consumption, the improvement in the efficiency of use of the backlight, that is, the transparency of the liquid crystal alignment film, is more stringent than in the past. .

Also, the display screen or backlight of the mobile phone or tablet terminal is due to Frequent switching, or from the moment of display and the viewpoint that the user is watching, there are new problems that are different from the conventional use.

Therefore, the present inventors focused on the asymmetry in the AC driving of the liquid crystal display element as a correlation factor of the display characteristics after the start of display. That is, the object of the present invention is to produce a liquid crystal alignment film which can maintain the characteristics necessary in the past, particularly the afterimage erasing time and the alignment control force, and has high transparency and is less prone to asymmetric driving of the AC drive. The resulting charge accumulation.

In order to solve the above problems, the inventors of the present invention have found that in the precursor of the highly aligned polyimine in the liquid crystal alignment film disclosed in Patent Document 2, a specific diamine is used as the diamine. When the divalent organic group is constructed, a liquid crystal alignment film exhibiting excellent properties with improved layer separation performance can be obtained, and the present invention has been completed.

In other words, the present invention provides a liquid crystal alignment agent containing at least one polyamine acid having a unit structure represented by the following formula (I) and a unit structure represented by the following formula (II) At least one of the polyamines.

(R ¹ represents an aromatic tetracarboxylic acid which is selected from the following structures (III) and (IV):

The tetravalent organic group, R ² represents a structure which can constitute a tetracarboxylic acid selected from the following structures (V) and (V'):

(R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a tetravalent organic group of a hydrogen atom or a methyl group), and R ³ represents a structure (VI) or (VII) having the following structure which can constitute a diamine:

(R ¹² represents an alkylene group having 2 to 8 carbon atoms)

The divalent organic group, R ⁴ represents a diamine which is selected from the following structure (VIII):

(R ⁹ and R ¹⁰ are each independently selected from a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group, R ¹¹ is an ether bond or a methylene group, and a represents an integer of 1 to 4)

Or the following structure (IX):

(R ¹³ and R ¹⁴ are each independently an alkylene group having 1 to 3 carbon atoms, and Y ¹ and Y ² are each independently a single bond, -O-, -S- or an ester bond, and Z is an oxygen atom or a sulfur atom. ) The organic base of 2 valence. )

According to another aspect of the present invention, a liquid crystal alignment film obtained by applying the liquid crystal alignment agent onto a substrate, performing a rubbing treatment after firing, and a liquid crystal display element using the liquid crystal display element are also provided.

According to the present invention, it is possible to provide a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element using the same, which can maintain an afterimage disappearance time and alignment control force, have high transparency, and are less prone to AC drive asymmetry. The accumulation of charge due to oxidation.

Hereinafter, the present invention will be described in detail.

The liquid crystal alignment agent of the present invention is a composition for forming a liquid crystal alignment film, and is characterized in that it contains a polyamine acid 1 (hereinafter referred to as PAA1) having a structural unit represented by the general formula (I). Polyhistidine 2 (hereinafter referred to as PAA2) of the structural unit represented by the formula (II).

The content of PAA1 and PAA2 is, in relation to the total amount of both, PAA1 is 20 to 70% by mass, more preferably 40 to 60% by mass, most preferably about 50% by mass. That is, the PAA2 is 80 to 30% by mass, preferably 60 to 40% by mass, and most preferably about 50% by mass based on the total amount of PAA1 and PAA2. When the amount of PAA1 is too small, the alignment property of the liquid crystal or the alignment control force is deteriorated, and if the PAA2 is too small, the charge storage characteristics of the liquid crystal alignment film are deteriorated. The PAA1 and PAA2 contained in the liquid crystal alignment agent of the present invention may be one type or two or more types, respectively. Further, in order to obtain a liquid crystal alignment film which is less likely to cause charge accumulation due to asymmetry of the AC drive, when PAA1 and PAA2 are mixed to form a liquid crystal alignment film, the polyamic acid does not easily cause layer separation, so it is preferred. .

Polylysine 1 (PAA1)

PAA1 is a highly conjugated polyimine precursor (polyglycine) having the structural unit represented by the above formula (I). The liquid crystal alignment film containing these structures is excellent in liquid crystal alignment and alignment control. R ^{1 of the} above formula (I) contains a tetravalent organic group constituting the aromatic tetracarboxylic acid, and it may be used alone or in combination of two or more. The tetracarboxylic acid having such a configuration may, for example, be a pyroic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8 -naphthalenetetracarboxylic acid, 2,3,6,7-nonanetetracarboxylic acid, 1,2,5,6-nonanetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2, 3,3',4-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl)ether, 3,3',4,4'-diphenyl ketone tetracarboxylic acid, bis(3,4- Dicarboxyphenyl)anthracene, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexa Fluorin-2,2'-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylnonane, bis(3,4-dicarboxyphenyl)diphenylnonane 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, etc., from the viewpoint of reducing the afterimage characteristics of the alignment of the liquid crystal, preferably R ¹ is a tetravalent organic group selected from the following structures.

The tetracarboxylic acid having such a configuration may, for example, be mayoleic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 3,3', 4,4'-diphenyl ketone tetracarboxylic acid, bis(3,4-dicarboxyphenyl) ether, etc., particularly preferably pyromic acid. The aromatic tetracarboxylic acid may be at least 50 mol% or more, preferably 70 mol% or more, 80 mol% or more, or 90 mol, of R ¹ of the formula (I) constituting PAA1. More than 8% of the ear.

In the above formula (I), R ³ includes a divalent organic group which is a monovalent group of the diamine, and may be one type or two or more types, and at least one type must be contained. (VI):

Or formula (VII):

A divalent organic group of either or both. R ^{12 of the} above formula (VII) is preferably an alkylene group having 2 to 8 carbon atoms, more preferably an alkylene group having 3 to 6 carbon atoms, and examples thereof include a propyl group, a butyl group, and a butyl group. Further, it is preferably a butyl group or a pentyl group having 4 or 5 carbon atoms.

In a preferred embodiment of the invention, R ³ in formula (I) is 1,3-bis(4-aminophenoxy)benzene or 1,5-bis(4-aminophenoxy). a 2 valent organic group of pentane.

In R ³ of the formula (I), the ratio of R ³ having the specific structure is preferably from 10 to 100 mol%, more preferably from 50 to 100 mol%. If the ratio is too small, the fluctuation characteristics of the flicker will deteriorate. R having the above-described configuration of other specific configurations of the presence of R ^{3 3} of the mixing is not particularly limited.

Specific examples of the compound constituting the other diamine of the structure of R ^{3 are} as follows. For example, p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2, 4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3, 5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamine linkage Benzene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy -4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 3,3'-trifluoromethyl-4,4'-diamine linkage Benzene, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4' -diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2, 3'-Diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldiphenylamine, 3,3'-sulfonyldiphenylamine, double ( 4 -aminophenyl)decane, bis(3-aminophenyl)decane, dimethyl-bis(4-aminophenyl)decane, dimethyl-bis(3-aminophenyl)decane, 4 , 4'-thiodiphenylamine, 3,3'-thiodiphenylamine, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'- Diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl (4,4'-diaminodiphenyl Amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl (2,2' -diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'-diaminodiphenyl ketone, 3,3'-diamino Diphenyl ketone, 3,4'-diaminodiphenyl ketone, 1,4-diaminonaphthalene, 2,2'-diaminodiphenyl ketone, 2,3'-diaminodiphenyl Ketone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2, 6-Diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-amine Phenyl) ethane, 1,3-(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butyl Alkane, 1,4-bis(3-amine Phenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-amino Phenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenethyl)urea, N-methyl-2-(4-aminophenyl) Ethylamine, 4,4'-[1,4-phenylenebis(methylene)diphenylamine], 4,4'-[1,3-phenylenebis(methylene)]diphenylamine , 3,4'-[1,4-phenylenebis(methylene)]diphenylamine, 3,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,3 '-[1,4-phenylenebis(methylene)]diphenylamine, 3,3'-[1,3-phenylenebis(methylene)]diphenylamine, 1,4-phenylene Bis[(4-aminophenyl)methanone], 1,4-phenylene bis[(3-aminophenyl)methanone], 1,3-phenylene bis[(4-aminobenzene) Methyl ketone], 1,3-phenylene bis[(3-aminophenyl)methanone], 1,4-phenylphenylbis(4-aminodiphenyl ketone), 1,4- Phenyl bis(3-aminodiphenyl ketone), 1,3-phenylene bis(4-aminodiphenyl ketone), 1,3-phenylene bis(3-aminodiphenyl) Ketone), bis(4-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate , N,N'-(1,4-phenylene)bis(4-aminobenzylamine), N,N' -(1,3-phenylene)bis(4-aminobenzylbenzylamine), N,N'-(1,4-phenylene)bis(3-aminobenzamide), N,N' -(1,3-phenylene)bis(3-aminobenzamide), N,N'-bis(4-aminophenyl)terephthalamide, N,N'-double (3 -aminophenyl)terephthalamide, N,N'-bis(4-aminophenyl)m-xylyleneamine, N,N'-bis(3-aminophenyl)isophthalene Dimethylamine, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenylhydrazine, 2,2'-bis[4-(4 -aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl) Hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2' - bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 1 , 3-bis(3-aminophenoxy)propane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(3-aminophenoxy)pentane, 1 ,6-bis(3-aminophenoxy)hexane, 1,7-(3-aminophenoxy)heptane, 1,8-bis(3-aminophenoxy)octane, 1 , 9-bis(4-aminophenoxy)decane, 1,9-bis(3-aminophenoxy)decane, 1,10-(4-amine Phenoxy group) decane, 1,10-(3-aminophenoxy)decane, 1,11-(4-aminophenoxy)undecane, 1,11-(3-amino group Phenoxy)undecane, 1,12-(4-aminophenoxy)dodecane, 1,12-(3-aminophenoxy)dodecane, bis(4-aminocyclohexyl) Methane, bis(4-amino-3-methylcyclohexyl)methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1, 6-Diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminodecane, 1,10-diaminodecane, 1, 11-Diaminoundecane, 1,12-diaminododecane, and the like. Among them, from the viewpoint of good alignment and the like, it is preferred to use 4,4'-diaminodiphenylmethane, 1,3-bis(4-aminophenethyl)urea, N-methyl-2. -(4-Aminophenyl)ethylamine.

One of the above-mentioned other diamine compounds can be used as a liquid crystal alignment film in terms of volume resistivity, friction resistance, ion density characteristics, transmittance, liquid crystal alignment property, voltage retention characteristics, and charge accumulation. Or use in combination of 2 or more types.

In the formula (VI), one or a plurality of arbitrary hydrogen atoms on the benzene ring may be substituted with a monovalent organic group other than the primary amine group. The monovalent organic group may, for example, be an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a fluorine-containing alkyl group having 1 to 20 carbon atoms, or a carbon number. 2 to 20 fluorine-containing alkenyl group, carbon number 1 to 20 fluorine-containing alkoxy group, cyclohexyl group, phenyl group, fluorine atom or a combination thereof. From the viewpoint of the alignment of the liquid crystal, it is preferably selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a fluorine having 1 to 4 carbon atoms. The monovalent organic group in the group consisting of an alkyl group, a fluorine-containing alkenyl group having 2 to 4 carbon atoms, and a fluorine-containing alkyl group having 1 to 4 carbon atoms. A more preferred structure is one in which the hydrogen atom on the benzene ring is not substituted.

The diamine having the structure of the above formula (VI) may, for example, be a 1,3-bis(4-amine Phenoxy group) benzene, 1,4-bis(4-aminophenoxy)benzene, etc., and from the viewpoint of fluctuation characteristics of scintillation, 1,3-bis(4-aminophenoxy)benzene is good.

Polyamine 2 (PAA2)

PAA2 is a polyimine precursor (polyglycine) which contributes to a component of charge storage characteristics of a liquid crystal alignment film, and has a structural unit represented by the general formula (II). The volume resistivity exhibited by the polyamic acid as a film is preferably 1 × 10 ¹⁰ to 1 × 10 ¹⁴ Ωcm. If the volume resistivity is too high, the image sticking and variation due to charge accumulation may occur, and if it is too low, the voltage holding characteristics may be deteriorated.

R ^{2 of the} formula (II) includes a tetravalent organic group constituting the tetracarboxylic acid, and it may be used alone or in combination of two or more. The tetracarboxylic acid having such a configuration may, for example, be 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid or 2,3,4,5-tetrahydrofuran. Tetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,4-dicarboxy-1-cyclohexyl succinic acid, 3,4-dicarboxy-1,2,3,4-tetrahydrogen 1-naphthylsuccinic acid, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic acid, 2,3,5-trihydroxycyclopentylacetic acid, etc., from the electrical components obtained From the viewpoint of characteristics, R ² is preferably a tetravalent organic group selected from the following structures (V) and (V').

(R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom or a methyl group)

The tetracarboxylic acid having such a configuration may, for example, be 1,2,3,4-cyclobutanetetracarboxylic acid or 1,2,3,4-butanetetracarboxylic dianhydride or such derivatives, particularly 1,2,3,4-cyclobutanetetracarboxylic acid is preferred. The tetracarboxylic acid is preferably at least 50 mol%, more preferably 70 mol% or more, 80 mol% or more, or 90 mol% or more of R ² of the formula (II) constituting PAA ² . . The structure of the other R ² is not particularly limited, and 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 1,2,4,5-ring can be used. Hexanetetracarboxylic acid, 3,4-dicarboxy-1-cyclohexyl succinic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, bicyclo[3,3, 0] octane-2,4,6,8-tetracarboxylic acid, 2,3,5-trihydroxycyclopentyl acetic acid and the like.

R ^{4 of the} above formula (II) is a divalent organic group which constitutes a diamine, and these may be the same or different from each other, and may be used alone or in combination of two or more. The diamine having such a structure may, for example, be a p-phenylene diamine, an exophenylene diamine, a 2,5-diaminotoluene, a 2,6-diaminotoluene or a 4,4'-diamine group. Benzene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, diaminodiphenylmethane , diaminodiphenyl ether, 2,2'-diaminodiphenylpropane, bis(3,5-diethyl-4-aminophenyl)methane, 1,3-bis(4-amine An aromatic diamine such as phenylethyl)urea. Among these, from the viewpoint of afterimage characteristics, it is preferred that R ^{4 is} independently a divalent organic group selected from the following structures (VIII) and (IX).

(R ⁹ and R ¹⁰ are each independently selected from a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group, R ¹¹ is an ether bond or a methylene group, and a represents an integer of 1 to 4)

(R ¹³ and R ¹⁴ are each independently an alkylene group having 1 to 3 carbon atoms, and Y ¹ and Y ² are each independently a single bond, -O-, -S- or an ester bond, and Z is an oxygen atom or a sulfur atom. .)

The diamine having such a configuration may, for example, be 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane or 3,4'-diaminodiphenylmethane, 2 , 2'-diaminodiphenyl ether, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether , 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 1,3-bis(4-amino group Phenylethyl)urea and the like. The ratio of R ⁴ having this specific structure is preferably 50 to 100 mol%, and if the ratio is too small, the afterimage characteristics are deteriorated.

In addition, as long as the object of the present invention is not impaired, the other diamine may be used in combination with R ⁴ having the above specific structure, and one type may be used or two or more types may be used in combination. Specific examples thereof include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, and exo-phenylene. Amine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diamine Phenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'- Diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3 '-Dihydroxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 3,3'-trifluoromethyl-4,4'- Diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'-sulfonyldiphenylamine, 3,3'-sulfonyldiphenylamine, bis(4-aminophenyl)decane, bis(3-aminophenyl)decane, dimethyl-bis ( 4-aminophenyl)decane, dimethyl-bis(3-aminophenyl)decane, 4,4'-thiodiphenylamine, 3,3'-thiodiphenylamine, 4,4'-di Aminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-Diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine , N-methyl (3,4'-diaminodiphenyl)amine, N-methyl (2,2'-diaminodiphenyl)amine, N-methyl (2,3'-di Aminodiphenyl)amine, 4,4'-diaminodiphenyl ketone, 3,3'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 1,4 -diaminonaphthalene, 2,2'-diaminodiphenyl ketone, 2,3'-diaminodiphenyl ketone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-Diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-di Amino naphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis (3) ,5-Diethyl-4-aminophenyl)methane, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4- Bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenethyl)urea, N-methyl-2-(4-aminophenyl)ethylamine, 4,4' -[1,4-phenylenebis(methylene)diphenylamine], 4,4'-[1,3-phenylene double ( Methyl)]diphenylamine, 3,4'-[1,4-phenylenebis(methylene)]diphenylamine, 3,4'-[1,3-phenylenebis(methylene)] Diphenylamine, 3,3'-[1,4-phenylenebis(methylene)]diphenylamine, 3,3'-[1,3-phenylenebis(methylene)]diphenylamine, 1 , 4-phenylene bis[(4-aminophenyl)methanone], 1,4-phenylene bis[(3-aminophenyl)methanone], 1,3-phenylene bis[ (4-aminophenyl)methanone], 1,3-phenylphenylbis[(3-aminophenyl)methanone], 1,4-phenylphenylbis(4-aminodiphenyl ketone) ), 1,4-phenylene bis(3-aminodiphenyl ketone), 1,3-phenylene bis(4-aminodiphenyl ketone), 1,3-phenylene bis (3) -aminodiphenyl ketone), bis(4-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl) Isophthalate, N,N'-(1,4-phenylene)bis(4-aminobenzylamine), N,N'-(1,3-phenylene)bis(4- Aminobenzylamine, N,N'-(1,4-phenylene)bis(3-aminobenzylamine), N,N'-(1,3-phenylene)bis(3- Aminobenzylamine, N,N'-bis(4-aminophenyl)terephthalamide, N,N'-bis(3-aminophenyl)terephthalamide, N , N'-bis(4-aminophenyl)m-xylyleneamine, N,N'-bis(3-aminophenyl) M-xylyleneamine, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenylhydrazine, 2,2'-bis[4- (4-Aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-amino group Phenyl) hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2, 2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane , 1,3-bis(4-aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)g Alkane, 1,7-(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octyl Alkane, 1,9-bis(4-aminophenoxy)decane, 1,9-bis(3-aminophenoxy)decane, 1,10-(4-aminophenoxy)anthracene Alkane, 1,10-(3-aminophenoxy)decane, 1,11-(4-aminophenoxy) Monoalkane, 1,11-(3-aminophenoxy)undecane, 1,12-(4-aminophenoxy)dodecane, 1,12-(3-aminophenoxy) Dodecane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminodecane, 1,10-Diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, and the like. Among them, 1,3-bis(4-aminophenethyl)urea is preferably used from the viewpoint of good electrical properties and the like.

Synthesis of polyaminic acid

When the polylysine used in PAA1 or PAA2 is obtained by a reaction of a tetracarboxylic dianhydride and a diamine, a method in which a tetracarboxylic dianhydride and a diamine are mixed and reacted in an organic solvent is simple.

The organic solvent to be used in the above reaction is not particularly limited as long as it can dissolve the produced polyamic acid. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyridone, and N-methylcaprolactam. , dimethyl hydrazine, tetramethyl urea, pyridine, dimethyl hydrazine, hexamethylene fluorene, γ-butyrolactone and the like. These may be used singly or in combination. Further, even a solvent which does not dissolve polyamic acid may be used in combination with the above solvent as long as it does not precipitate in the formed polyamine. Further, since the water in the organic solvent hinders the polymerization reaction and causes hydrolysis of the produced polylysine, it is preferred that the organic solvent be dehydrated and dried as much as possible.

A method of mixing a tetracarboxylic dianhydride component and a diamine component in an organic solvent, for example, a solution in which a diamine component is dispersed or dissolved in an organic solvent is stirred, and a tetracarboxylic dianhydride component is directly Or a method of dispersing or dissolving in an organic solvent; conversely, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent; and mutually adding a tetracarboxylic dianhydride component and a diamine component The method and the like can be any of the methods in the present invention. Further, when the tetracarboxylic dianhydride component or the diamine component is composed of a plurality of compounds, the components may be reacted in a state of being mixed in advance, or may be reacted individually.

The temperature at which the tetracarboxylic dianhydride component and the diamine component are reacted in an organic solvent is usually 0 to 150 ° C, preferably 5 to 100 ° C, more preferably 10 to 80 ° C. The higher the temperature, the earlier the polymerization reaction ends, but if it is too high, there is a case where a polymer having a high molecular weight cannot be obtained. Further, the reaction can be carried out at any concentration. However, if the concentration is too low, it is difficult to obtain a polymer having a high molecular weight. If the concentration is too high, the viscosity of the reaction liquid becomes too high and it is difficult to uniformly stir. Therefore, it is preferably 1 to 50. The mass %, more preferably 5 to 30% by mass. It can also be carried out at a high concentration in the initial stage of the reaction, and then an organic solvent is added.

The ratio of the tetracarboxylic dianhydride component to the diamine component used in the polymerization of polyamic acid is preferably from 1:0.8 to 1.2 in terms of a molar ratio. Further, in the case where the polyamine derivative obtained by excess of the diamine component is colored, the color of the solution may become large. Therefore, when the color of the solution is desired, the ratio is preferably 1:0.8 to 1. As with the general polycondensation reaction, the molecular weight of the polyamine which is obtained by getting the molar ratio closer to 1:1 is larger. The smaller the molecular weight of poly-proline, the less the strength of the coating obtained from it. The opposite molecule of poly-proline When the amount is too large, the viscosity of the solution when the liquid crystal alignment agent is used as a coating solution becomes too high, and the workability at the time of forming the coating film and the uniformity of the coating film are deteriorated.

Further, the weight average molecular weight of the polyamic acid is preferably 5,000 to 300,000, more preferably 10,000 to 200,000, and the number average molecular weight is preferably 2,500 to 150,000, more preferably 5,000 to 100,000.

When the liquid crystal alignment agent of the present invention does not contain a solvent used for polymerization of polylysine or when an unreacted monomer component or impurity is present in the reaction solution and is to be removed, polyamine is carried out. The acid precipitate is recovered and refined. In the method, the method in which the polyproline solution is put into a poor solvent in agitation to precipitate and recover it is simple. The poor solvent used for the precipitation of the polyamic acid is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. Wait. The polylysine precipitated by the introduction of a poor solvent is filtered, washed, and recovered, and then dried at normal temperature or under reduced pressure to form a powder. The powder is redissolved in a good solvent, and the reprecipitation operation is repeated 2 to 10 times, and the polyaminic acid can also be purified. When the primary precipitation recovery operation cannot completely remove the impurities, it is preferred to carry out the purification step. In the case of the poor solvent at this time, for example, three or more kinds of poor solvents such as alcohols, ketones, and hydrocarbons can be used, and the purification efficiency can be further improved, which is preferable. The above-described precipitation recovery and purification operation can be carried out in the same manner in the synthesis of a polyalkylenimine or a polyimine which will be described later.

When a part or all of the polyamic acid is imidized, the production method thereof is not particularly limited, and the polyamine can be reacted with the dicarboxylic acid dianhydride and the diamine. The acid is directly imidized in solution. At this time, when a part or all of the polyamic acid is converted into a polyimine, a method of chemically ring-closing by a method of dehydration ring closure by heating or a well-known dehydration ring-closing catalyst is employed. Any temperature of from 100 ° C to 300 ° C, preferably from 120 ° C to 250 ° C, may be selected by heating. In the chemical ring closure method, for example, pyridine or triethylamine can be used in the presence of acetic anhydride or the like, and the temperature can be selected from any temperature of from -20 ° C to 200 ° C.

Liquid crystal alignment agent

The form of the liquid crystal alignment agent of the present invention described below is a coating liquid containing PAA1 and PAA2. However, other forms may be used as long as a uniform film can be formed on the substrate. When the coating liquid containing PAA1 and PAA2 is prepared, the reaction solution containing each polylysine may be directly mixed, or the solid component polylysine may be dissolved in an organic solvent and mixed, or may be a solid component. The polyamic acid is mixed while being dissolved in an organic solvent. The mixing ratio of PAA1 and PAA2, as described above, is preferably 2:8 to 7:3, more preferably 3:8 to 7:3, and even more preferably 4:6 by mass ratio (PAA1: PAA2). 6:4, especially good for 5:5. By setting the ratio to be within this range, a liquid crystal alignment agent having good liquid crystal alignment properties and electrical properties can be obtained.

The organic solvent is not particularly limited as long as it can dissolve the resin component contained therein, and specific examples thereof include N,N-dimethylformamide and N,N-dimethyl B. Indoleamine, N-methyl-2-pyridone, N-methylcaprolactam, 2-pyridone, N-ethylpyridone, N-vinylpyridone, dimethyl hydrazine, tetramethylurea , pyridine, dimethylhydrazine, hexamethylene ytterbium, γ - Butyrolactone or the like, which may be used singly or in combination of plural kinds.

Moreover, even if it is a solvent which cannot melt|dissolve a resin component individually, it can mix with the liquid-crystal-aligning agent of this invention as long as it is the range which the resin component does not isolate. In particular, by moderately mixing, there are a mixture of cesasu, dingsasu, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2. -propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol -1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, lactate B A solvent having a low surface tension such as ester, n-propyl lactate, n-butyl lactate or isoamyl lactate, which is known to improve coating film uniformity when applied to a substrate, and is also suitable for use in the liquid crystal alignment agent of the present invention. .

In the coating liquid of the liquid crystal alignment agent of the present invention, the solid content concentration can be appropriately changed depending on the setting of the thickness of the liquid crystal alignment film to be formed, and is preferably 1 to 10% by mass. When it is less than 1% by mass, it is difficult to form a uniform and defect-free coating film, and if it is more than 10% by mass, the storage stability of the solution may be deteriorated.

Further, in the liquid crystal alignment agent of the present invention, in order to improve the adhesion to the coating film of the substrate, an additive such as a decane coupling agent may be added, or another resin component may be added.

The liquid crystal alignment agent of the present invention obtained as described above is applied to a substrate after being filtered, and can be dried and fired to form a coating film, and the coating film surface can be subjected to alignment treatment such as rubbing or light irradiation. Use as a liquid crystal alignment film.

In this case, the substrate to be used is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as a glass substrate, an acrylic substrate or a polycarbonate substrate can be used, and an ITO electrode or the like which is driven by a liquid crystal can be used. The substrate is preferred in terms of simplification of the process. Further, in the reflective liquid crystal display device, an opaque material such as a germanium wafer can be used only for the substrate on one side, and a material such as aluminum that reflects light can be used as the electrode in this case.

The coating method of the liquid crystal alignment agent may, for example, be a spin coating method, a printing method, an inkjet method, or the like. The transfer printing method is widely used from the viewpoint of productivity, and is also applicable to the liquid crystal alignment agent of the present invention.

The step of drying after applying the liquid crystal alignment agent is not necessarily required. When the time from the coating to the time of baking is not fixed depending on the substrate, it is preferred to include a drying step when it is not required to be immediately fired after coating. In the drying, the solvent is evaporated to such an extent that the shape of the coating film is not deformed by the conveyance of the substrate, and the drying means is not particularly limited. As a specific example, for example, a method of drying on a hot plate of 50 to 150 ° C, preferably 80 to 120 ° C, for 0.5 to 30 minutes, preferably 1 to 5 minutes.

The firing of the liquid crystal alignment agent can be carried out at a temperature of from 100 to 350 ° C, preferably from 150 to 300 ° C, more preferably from 200 to 250 ° C. When the polyimine precursor is contained in the liquid crystal alignment agent, the conversion ratio of the polyimide precursor to the polyimine is changed depending on the firing temperature thereof, and the liquid crystal alignment agent of the present invention is not necessarily To be 100% ruthenium. However, it is preferred to carry out the firing at a temperature higher than the heat treatment temperature of the sealant hardening or the like which is necessary in the liquid crystal cell process by 10 ° C or higher.

The thickness of the coating film after firing is too large to be eliminated by the liquid crystal display element The power is unfavorable, and if it is too thin, the reliability of the liquid crystal display element is lowered, so it is 5 to 300 nm, preferably 10 to 100 nm.

Liquid crystal display element

In the liquid crystal display device of the present invention, a substrate having a liquid crystal alignment film is obtained from the liquid crystal alignment agent of the present invention by the above-described method, and then a liquid crystal cell is produced by a known method to prepare a liquid crystal display element. In the case of producing a liquid crystal cell, generally, a pair of substrates on which a liquid crystal alignment film is formed is sandwiched between the pillars of generally 1 to 30 μm, preferably 2 to 10 μm, preferably set to have a rubbing direction of 0. The method of fixing the liquid crystal and sealing it at any angle of ~270° and fixing the periphery with a sealant is a general method. When the liquid crystal alignment film is subjected to rubbing treatment, an existing friction device can be used. The material of the rubbing cloth at this time may, for example, be cotton, crepe, nylon or the like. The method of liquid crystal sealing is not particularly limited, and examples thereof include a vacuum method in which a liquid crystal cell to be produced is decompressed and then injected into a liquid crystal, a dropping method in which a liquid crystal is dropped, and a sealing method.

As described above, the liquid crystal display element produced by using the liquid crystal alignment agent of the present invention has excellent alignment properties and alignment control power, and has excellent electrical characteristics. Therefore, it is possible to produce a liquid crystal display element which is less likely to lower contrast or cause image sticking. Among these liquid crystal display elements, it is particularly preferable to use a lateral electric field type liquid crystal display element which is less likely to cause image sticking from the alignment control force.

[Examples]

Regarding the detailed manufacturing method of the present invention, the following is a discussion of raw materials. The experimental methods of the composition or the compounding ratio and the results thereof, as well as examples of typical manufacturing methods, and the like are explained. Further, the invention is not limited to the embodiments.

The description of the abbreviation used in this embodiment.

(tetracarboxylic dianhydride)

CA-1: tartaric acid dianhydride

CA-2: 1,2,3,4-cyclobutane tetracarboxylic dianhydride

CA-3: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride

(diamine)

DA-1: 4,4'-diaminodiphenyl ether

DA-2: 4,4'-diaminodiphenylmethane

DA-3: 1,3-bis(4-aminophenethyl)urea

DA-4: 1,3-bis(4-aminophenoxy)benzene

DA-5: 1,5-bis(4-aminophenoxy)pentane

DA-6: 4,4'-diaminodiphenylamine

DA-7: N-methyl-2-(4-aminophenyl)ethylamine

DA-8: 1,3-bis(4-aminophenoxy)propane

(Organic solvents)

NMP: N-methyl-2-pyridin

GBL: γ-butyrolactone

BCS: butyl cellosolve

Each measurement method is shown below.

(Measurement of transmittance (visual transmittance evaluation))

The obtained liquid crystal alignment agent was filtered through a 1.0 μm filter, and then the alignment agent was spin-coated on a quartz substrate, dried on a hot plate at 50° C. for 5 minutes, and then baked at 230° C. for 30 minutes to form a film having a thickness of 100 nm.醯 imine film. A double-sided tape is attached only to both sides of the substrate facing the coating film surface, and is bonded to a quartz substrate on which no film is formed. The liquid wax was injected into the simple cell prepared in this manner, and the transmittance was measured using UV-3100PC manufactured by Shimadzu Corporation. From the obtained data, the visual transmittance was calculated, and the value of the value of 96% or more was evaluated as "good", and the definition of "less than 96%" was evaluated as "poor". The evaluation results are shown in Table 3.

Prepare the substrate with the electrode first. The substrate was a glass substrate having a size of 30 mm × 50 mm and a thickness of 0.7 mm. On the substrate, as the first layer, an ITO electrode having a flat pattern constituting the counter electrode was formed. On the counter electrode of the first layer, a SiN (tantalum nitride) film formed by a CVD method was formed as the second layer. The SiN film of the second layer has a film thickness of 500 nm and has a function as an interlayer insulating film. On the SiN film of the second layer, as the third layer, two pixels of the first pixel and the second pixel in which the comb-shaped pixel electrode formed by patterning the ITO film is disposed are formed. The size of each pixel is 10 mm in length and 5 mm in width. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the action of the SiN film of the second layer.

The pixel electrode of the third layer has a comb-like shape in which a plurality of electrode elements having a U-shaped shape in which a central portion is curved are arranged in a plurality. Electrode element The width in the short side direction was 3 μm, and the interval between the electrode elements was 6 μm. Since the pixel electrodes forming the respective pixels are formed by arranging a plurality of U-shaped electrode elements in which the central portion is curved, the shape of each pixel is not rectangular, and is curved at the center portion like the electrode elements, and has a shape similar to that of the thick body. The shape of the ㄑ shape. Each of the pixels is divided into upper and lower sides by a curved portion at the center thereof, and has a first region on the upper side of the curved portion and a second region on the lower side.

When the first region and the second region of each pixel are compared, the direction in which the electrode elements constituting the pixel electrodes are formed is different. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, the electrode elements of the pixel electrode of the first region of the pixel are formed at an angle of +10° (clockwise) so that the pixel is The electrode elements of the pixel electrodes of the 2 regions are formed at an angle of -10° (clockwise). That is, in the first region and the second region of each pixel, the direction of the in-plane switching in the surface of the substrate in which the liquid crystal induced by the voltage between the pixel electrode and the counter electrode is applied is They are constructed in mutually opposite directions.

Next, the obtained liquid crystal alignment agent was filtered through a 1.0 μm filter, and then spin-coated on the prepared substrate with the electrode and the ITO film formed on the inner surface of the opposite substrate and having a columnar height of 4 μm. A glass substrate between the pillars. Subsequently, the film was dried on a hot plate at 50 ° C for 5 minutes, and then fired at 230 ° C for 30 minutes to obtain a polyimide film having a film thickness of 70 nm on each substrate. Ultrasonic irradiation in pure water was carried out on the polyimine film in a predetermined rubbing direction with rubbing (rolling diameter 120 mm, number of revolutions 500 rpm, moving speed 30 mm/sec, and pushing amount 0.3 mm). 1 In minutes, dry at 80 ° C for 10 minutes.

Thereafter, the above-described two kinds of substrates having the liquid crystal alignment film were used, and the rubbing directions were combined so as to be antiparallel, and only the liquid crystal injection port was left in the surrounding seal to form an empty liquid crystal cell having a liquid crystal layer gap of 3.6 μm. After the liquid crystal cell was vacuum-injected into the liquid crystal (MLC-2041, manufactured by Merck) at a normal temperature, the injection port was sealed to form an antiparallel alignment liquid crystal cell. The obtained liquid crystal cell constitutes an IPS mode liquid crystal display element. Thereafter, the obtained liquid crystal cell was heated at 110 ° C for 1 hour, and left for one night and used for each evaluation.

(afterimage evaluation)

The afterimage evaluation was performed using the following optical system or the like.

The produced liquid crystal cell is placed between two polarizing plates arranged such that the polarization axes are orthogonal, and the LED backlight is turned on without applying a voltage to minimize the brightness of the transmitted light. The method adjusts the configuration angle of the liquid crystal cells.

Next, a V-T curve (voltage-transmittance curve) was measured under an alternating current voltage of a frequency of 30 Hz applied to the liquid crystal cell, and an AC voltage of 23% with respect to a transmittance was calculated as a driving voltage.

The afterimage evaluation was performed by applying an AC voltage having a frequency of 30 Hz to drive the liquid crystal cell under a mode so that the relative transmittance was 23%, and applying a DC voltage of 2 V to drive it for 60 minutes. Thereafter, the application of the DC voltage value was 0 V to stop the application of the DC voltage, and the driving was further applied for 30 minutes in this state.

Afterimage evaluation, the time point from the application of the stop DC voltage is 60 In the minute, when the relative transmittance is restored to 25% or less, the definition evaluation is "good". When it takes more than 30 minutes for the relative transmittance to return to 25% or less, the definition is "poor".

On the other hand, the afterimage evaluation by the above method was carried out under the temperature conditions in which the temperature of the liquid crystal cell was 23 °C. The evaluation results are shown in Table 3.

(Evaluation of the charge accumulation value of the asymmetric drive)

The produced liquid crystal cell is placed between two polarizing plates arranged such that the polarization axes are orthogonal, and the LED backlight is turned on without applying a voltage to minimize the brightness of the transmitted light. The method adjusts the configuration angle of the liquid crystal cells.

Next, a V-T curve (voltage-transmittance curve) was measured under an alternating voltage of a frequency of 30 Hz applied to the liquid crystal cell, and an AC voltage of 50% with respect to a transmittance was calculated as a driving voltage.

The light is blocked in such a manner that the LED light does not illuminate the liquid crystal cell. And a rectangular wave of 20 mV was applied to the liquid crystal cell at a frequency of 1 kHz for 30 minutes.

Thereafter, an AC drive with a relative transmittance of 50% was performed simultaneously with the LED lighting, and a VF (voltage-flicker curve) curve after the lighting was measured, and the charge accumulation offset by the asymmetry of the AC drive was calculated. Voltage value. Thereafter, the amount of change in the minimum off-line voltage value was measured every minute, and the maximum voltage value up to 30 minutes after lighting was calculated. At this time, when the amount of change in the maximum off-line voltage exceeds 20 mV, the definition evaluation is "poor". Further, when the amount of change in the maximum off-line voltage does not exceed 20 mV, the definition is evaluated as "good".

(Residual image evaluation due to long-term driving)

Using this liquid crystal cell, an alternating voltage of 8 VPP was applied at a frequency of 30 Hz for 100 hours in a constant temperature environment of 60 °C. Thereafter, the pixel electrode of the liquid crystal cell and the counter electrode were short-circuited, and were placed at room temperature for one day.

After being placed, the liquid crystal cells are placed between two polarizing plates arranged such that the polarization axes are orthogonal, and the LED backlight is turned on without applying a voltage to minimize the brightness of the transmitted light. The method adjusts the configuration angle of the liquid crystal cells. On the other hand, the rotation angle at which the liquid crystal cell is rotated from the angle at which the second region of the first pixel is dark to the darkest angle of the first region is calculated as the angle Δ. Similarly to the second pixel, the second region is compared with the first region, and the angle Δ is calculated in the same manner. The average value of the angle Δ values of the first pixel and the second pixel is calculated as the angle Δ of the liquid crystal cell. When the value of the angle Δ of the liquid crystal cell exceeds 0.2, the definition is evaluated as "poor". When the value of the angle Δ of the liquid crystal cell did not exceed 0.2, the definition was evaluated as "good".

[Synthesis of Polymers] <Synthesis Example 1>

To a 200 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 14.3 g (48.0 mmol) of DA-4 and 141.3 g of N-methyl-2-pyridone were added, and the mixture was stirred and dissolved while supplying nitrogen. To the solution of the diamine solution, 10.05 g (46.0 mmol) of CA-1 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, and the mixture was stirred at water temperature for 20 hours. Polylysine solution (abbreviated as P1). E-type viscometer (made by Toki Sangyo Co., Ltd.) The viscosity of the poly-proline (P1) solution at 25 ° C was 271 mPa. s.

27.82 g of the polyplycine (P1) solution, 11.72 g of N-methyl-2-pyridone, and 13.18 g of butyl cellosolve were added to obtain a liquid crystal alignment treatment agent having a P1 concentration of 6.0% by mass.

<Synthesis Example 2>

Into a 50 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 3.04 g (10.4 mmol) of DA-4, 0.52 g (3.1 mmol) of DA-2, and 36.3 g of N-methyl-2-pyridone were added thereto. Stir in nitrogen to dissolve. Under stirring of the diamine solution, 2.64 g (12.5 mmol) of CA-1 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, and the mixture was stirred at water temperature for 20 hours. Polylysine solution (referred to as P2). The viscosity of the polyproline (P2) solution at 25 ° C was confirmed by an E-type viscosity meter (manufactured by Toki Sangyo Co., Ltd.) to be 316 mPa. s.

34.3 g of the polyaminic acid (P2) solution was added, 7.87 g of N-methyl-2-pyridone and 8.58 g of butyl cellosolve were added to obtain a liquid crystal alignment treatment agent having a P2 concentration of 6.0% by mass.

<Synthesis Example 3>

Into a 500 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 22.58 g (79.2 mmol) of DA-5, 10.52 g (52.8 mmol) of DA-6, and 310.1 g of N-methyl-2-pyridone were added thereto. Stir in nitrogen to dissolve. Add CA-21 27.21g (124.7mmol) under stirring of the diamine solution, and to solidify N-methyl-2-pyridone was added in such a manner that the concentration of the body component was 12% by mass, and the mixture was stirred at water temperature for 20 hours to obtain a solution of polylysine (abbreviated as P3). The viscosity of the polyproline (P3) solution at 25 ° C was confirmed to be 278 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

To the 271.4 g of the polyamine acid (P3) solution, 132.3 g of N-methyl-2-pyridone and 134.5 g of butyl cellosolve were added to obtain a liquid crystal alignment agent having a P3 concentration of 6.0% by mass.

<Synthesis Example 4>

To a 300 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 18.1 g (92.0 mmol) of DA-1 and 211.4 g of N-methyl-2-pyridone were added, and the mixture was stirred and dissolved while supplying nitrogen. Under stirring of the diamine solution, 17.56 g (89.5 mmol) of CA-2 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, and the mixture was stirred at water temperature for 20 hours. Polylysine solution (referred to as P4). The viscosity of the polyproline (P4) solution at 25 ° C was confirmed to be 301 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

To the solution of the polyaminic acid (P4) solution, 25.2 g, N-methyl-2-pyridone 9.86 g, and 1.0% by mass of N-methyl-2-carboxylate with 3-aminopropyltriethoxysilane 3.05 g of a pyridone solution and 12.71 g of a butyl cellosolve gave a liquid crystal alignment agent having a P4 concentration of 6.0% by mass.

<Synthesis Example 5>

In a 100 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, DA-2 6.15 g (31.0 mmol) and 70.65 g of N-methyl-2-pyridone were stirred and dissolved while feeding nitrogen. Under stirring of the diamine solution, 6.01 g (30.5 mmol) of CA-2 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, and the mixture was stirred at water temperature for 20 hours. Polylysine solution (referred to as P5). The viscosity of the polyproline (P5) solution at 25 ° C was confirmed to be 130 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

18.05 g of the polyaminic acid (P5) solution, 7.05 g of N-methyl-2-pyridone, and 1.0-% by mass of N-methyl-2-carboxylate with 3-aminopropyltriethoxy decane 2.18 g of a pyridone solution and 9.09 g of butyl cellosolve gave a liquid crystal alignment agent having a P5 concentration of 6.0% by mass.

<Synthesis Example 6>

In a 100 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, DA-2 4.02 g (20.3 mmol), DA-3 2.60 g (8.7 mmol), and N-methyl-2-pyridone 70.8 g were added. Stir in nitrogen to dissolve. Under stirring of the diamine solution, 5.61 g (28.5 mmol) of CA-2 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, and the mixture was stirred at water temperature for 5 hours. Polylysine solution (referred to as P6). The viscosity of the polyproline (P6) solution at 25 ° C was confirmed to be 249 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

In the polyacetic acid (P6) solution 18.02 g, N-methyl-2-pyridone 6.45 g was added, and 1.0-% by mass of 3-aminopropyltriethoxyoxane was added to N-methyl-2- 2.13 g of pyridone solution and 8.87 g of butyl cellosolve, P6 The liquid crystal alignment agent having a concentration of 6.0% by mass.

<Synthesis Example 7>

Into a 100 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, DA-3 10.6 g (35.4 mmol), DA-7 3.55 g (23.6 mmol), and N-methyl-2-pyridone 136.2 g were added. Stir in nitrogen to dissolve. Under stirring of the diamine solution, 11.3 g (57.6 mmol) of CA-2 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 10% by mass, and the mixture was stirred at water temperature for 5 hours. Polylysine solution (referred to as P7). The viscosity of the polyproline (P7) solution at 25 ° C was confirmed to be 154 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

58.97 g of the polyaminic acid (P7) solution, 38.69 g of N-methyl-2-pyridone, and 1.0-% by mass of N-methyl-2-carboxylate with 3-aminopropyltriethoxy decane 8.40 g of a pyridone solution and 35.38 g of a butyl cellosolve gave a liquid crystal alignment agent having a P7 concentration of 6.0% by mass.

<Synthesis Example 8>

In a 100 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, DA-4 3.80 g (13.0 mmol), DA-8 3.35 g (13.0 mmol), and N-methyl-2-pyridone 54.07 g were added. Stir in nitrogen to dissolve. Under stirring of the diamine solution under water cooling, 2.84 g (13.0 mmol) of CA-1 and 18.0 g of N-methyl-2-pyridone were added, and the mixture was stirred under a nitrogen atmosphere for 3 hours under water cooling. Thereafter, 2.29 g (11.7 mmol) of CA-2 and 18.0 g of N-methyl-2-pyridone were added, and the mixture was stirred and dissolved, and stirred under water cooling for 3 hours to obtain a polyfluorene. A solution of aminic acid (P8). The viscosity at 25 ° C of the polyproline (P8) solution was confirmed to be 164 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

Into 20.77 g of the polyamine acid (P8) solution, 20.77 g of N-methyl-2-pyridone and 10.06 g of butyl cellosolve were added to obtain a liquid crystal alignment agent having a P8 concentration of 6.0% by mass.

<Synthesis Example 9>

Into a 100 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 4.38 g (15.0 mmol) of DA-4, 2.58 g (10.0 mmol) of DA-8, and 70.94 g of N-methyl-2-pyridone were added thereto. Stir in nitrogen to dissolve. Under stirring of the diamine solution, 5.13 g (24.0 mmol) of CA-1 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, and the mixture was stirred at water temperature for 20 hours. Polylysine solution (referred to as P9). The viscosity of the polyamic acid (P9) solution at 25 ° C was confirmed to be 202 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

Into 21.44 g of the polyaminic acid (P9) solution, 8.28 g of N-methyl-2-pyridone and 9.91 g of butyl cellosolve were added to obtain a liquid crystal alignment agent having a P9 concentration of 6.0% by mass.

<Synthesis Example 10>

Into a 100 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, DA-4 3.04 g (10.0 mmol), DA-8 4.03 g (15.0 mmol), and N-methyl-2-pyridone 72.74 g were added. Stir in nitrogen to dissolve. Add 5.33 g (24.0 mmol) of CA-1 under stirring of the diamine solution, and to make a solid component N-methyl-2-pyridone was added in a concentration of 12% by mass, and stirred at a water temperature for 20 hours to obtain a solution of poly-proline (abbreviated as P10). The viscosity of the polyproline (P10) solution at 25 ° C was confirmed to be 395 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

Into 20.42 g of the polyplysine (P10) solution, 8.10 g of N-methyl-2-pyridone and 9.46 g of butyl cellosolve were added to obtain a liquid crystal alignment agent having a P10 concentration of 6.0% by mass.

<Synthesis Example 11>

In a 100 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 1.54 g (5.30 mmol) of DA-4, 3.04 g (10.6 mmol) of DA-5, 2.61 g of DA-6, and N-methyl-2-pyridine were added. 71.33 g of a ketone was stirred and dissolved while feeding nitrogen. Under stirring of the diamine solution, 5.46 g (25.0 mmol) of CA-1 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, and the mixture was stirred at water temperature for 20 hours. Polylysine solution (abbreviated as P11). The viscosity of the polyproline (P11) solution at 25 ° C was confirmed to be 895 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

To the solution of 20.57 g of the polyplycine (P11) solution, 10.15 g of N-methyl-2-pyridone and 9.57 g of butyl cellosolve were added to obtain a liquid crystal alignment agent having a P11 concentration of 4.6% by mass.

<Synthesis Example 13>

Into a 200 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 17.75 g (62.0 mmol) of DA-5 and 139.1 g of N-methyl-2-pyridone were added thereto. Stir in nitrogen to dissolve. Under stirring of the diamine solution, 12.91 g (59.2 mmol) of CA-1 was added, and N-methyl-2-pyridone was added in such a manner that the solid content concentration was 12% by mass, under a nitrogen atmosphere, The mixture was stirred under heating at 50 degrees for 20 hours to obtain a solution of polyamic acid (A1). The viscosity of the polyproline (P12) solution at 25 ° C was confirmed to be 530 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

50.00 g of the polyproline (P12) solution, 43.95 g of N-methyl-2-pyridone, and 1.0% by mass of N-methyl-2-carboxylate with 3-aminopropyltriethoxysilane 5.6 g of a pyridone solution and 24.89 g of a butyl cellosolve gave a liquid crystal alignment agent having a concentration of A1 of 4.5% by mass.

<Synthesis Example 12>

Into a 200 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 7.97 g (40.0 mmol) of DA-6 and 98.6 g of N-methyl-2-pyridone were added, and the mixture was stirred and dissolved while supplying nitrogen. Under stirring of the diamine solution under water cooling, 6.96 g (35.5 mmol) of CA-2 and 35.9 g of N-methyl-2-pyridone were added, and the mixture was stirred under a nitrogen atmosphere for 3 hours under water cooling. Thereafter, 1.98 g (10.0 mmol) of DA-2 and 17.9 g of N-methyl-2-pyridone were added, and the mixture was stirred and dissolved. After the DA-6 was dissolved, CA-3 3.00 g (10.0 mmol) and 26.9 g of N-methyl-2-pyridone were added, and the mixture was stirred under a nitrogen atmosphere for 3 hours under water to obtain a polyamic acid (P13). ) a solution. The viscosity of the polylysine (P13) solution at 25 ° C was confirmed to be 165 mPa by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). s.

50.00g of the polyproline (P13) solution, adding N-methyl-2-pyridine 10.55 g of a ketone, 4.9 g of a N-methyl-2-pyridone solution of 3-aminopropyltriethoxy decane, and 16.37 g of a butyl cellosolve were added in an amount of 1.0% by mass to obtain a P13 concentration of 6.0% by mass. Solution.

<Example 1>

The polyaminic acid solution (P1) obtained in Synthesis Example 1 and the polyamic acid solution (P4) obtained in Synthesis Example 4 were mixed in a mass ratio of 50:50 to obtain a polyamidonic acid solution (A-1). ).

<Example 2>

The polyaminic acid solution (P1) obtained in Synthesis Example 1 and the polyamic acid solution (P5) obtained in Synthesis Example 5 were mixed in a mass ratio of 50:50 to obtain a polyaminic acid solution (A-2). ).

<Example 3>

The polyaminic acid solution (P2) obtained in Synthesis Example 2 and the polyamic acid solution (P6) obtained in Synthesis Example 6 were mixed in a mass ratio of 50:50 to obtain a polyaminic acid solution (A-3). ).

<Example 4>

The polyaminic acid solution (P3) obtained in Synthesis Example 3 and the polyaminic acid solution (P6) obtained in Synthesis Example 6 were mixed in a mass ratio of 30:70 to obtain a poly-proline solution (A-4). ).

<Example 5>

The polyaminic acid solution (P11) obtained in Synthesis Example 11 and the polyamic acid solution (P7) obtained in Synthesis Example 7 were mixed in a mass ratio of 30:70 to obtain a polyaminic acid solution (A-5). ).

<Example 6>

The polyaminic acid solution (P9) obtained in Synthesis Example 9 and the polyaminic acid solution (P6) obtained in Synthesis Example 6 were mixed in a mass ratio of 40:60 to obtain a polyamic acid solution (A-6). ).

<Example 7>

The polyaminic acid solution (P9) obtained in Synthesis Example 9 and the polyamic acid solution (P7) obtained in Synthesis Example 7 were mixed in a mass ratio of 40:60 to obtain a polyaminic acid solution (A-7). ).

<Comparative Example 1>

The polyaminic acid solution (P13) obtained in Synthesis Example 13 was used as a comparative example (B-1) for evaluation.

<Comparative Example 2>

The polyaminic acid solution (P4) obtained in Synthesis Example 4 was used as a comparative example (B-2) and used for evaluation.

<Comparative Example 3>

The polyaminic acid solution (P8) obtained in Synthesis Example 8 was used as a comparative example (B-3) for evaluation.

<Comparative Example 4>

The polyaminic acid solution (P13) obtained in Synthesis Example 13 and the polyamic acid solution (P12) obtained in Synthesis Example 12 were mixed in a mass ratio of 20:80 to obtain a polyamidonic acid solution (B-4). ).

<Comparative Example 5>

The polyaminic acid solution (P10) obtained in Synthesis Example 10 and the polyamic acid solution (P6) obtained in Synthesis Example 6 were mixed in a mass ratio of 40:60 to obtain a polyaminic acid solution (B-5). ).

Table 1 shows the ratio of the tetracarboxylic dianhydride component and the diamine component of P1 to P13 used in the preparation of each of the above polyamine solutions of Examples 1 to 7 and Comparative Examples 1 to 5.

Further, the mixing ratios of the respective polyamine solutions in Examples 1 to 7 and Comparative Examples 1 to 5 are shown in Table 2.

Further, the film produced by each of the polyacrylic acid solutions of Examples 1 to 7 and Comparative Examples 1 to 5 and the visual transmittance evaluation, afterimage evaluation, and residual image obtained by long-term driving were obtained from the liquid crystal cell. The results of the evaluation of the charge accumulation value due to the evaluation and the asymmetry of the AC drive are shown in Table 3.

As described above, the polyacrylic acid of the present invention produced in Examples 1 to 6 was evaluated for visual transmittance, afterimage evaluation, afterimage evaluation by long-term driving, and charge due to asymmetry of AC driving. The accumulation value evaluation showed good results, but the polyamines produced in Comparative Examples 1 to 4 all had poor results, especially in the evaluation of the charge accumulation value due to the asymmetry of the AC drive. The results which are significantly different from the properties of the poly-proline of the present invention are obtained.

Claims (7)

A liquid crystal alignment agent characterized by containing at least one of a polyglycine containing a unit structure represented by the following formula (I) and at least one of a unit structure represented by the following formula (II) Proline (R ¹ represents an aromatic tetracarboxylic acid which is selected from the following structures (III) and (IV) a tetravalent organic group, and R ² represents a tetracarboxylic acid which is selected from the following structures (V) or (V') (R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a tetravalent organic group of a hydrogen atom or a methyl group), and R ³ represents a structure (VI) having a diamine which can constitute a diamine Or formula (VII) (R ¹² represents a divalent organic group of a C 2-8 alkyl group), and R ⁴ represents a diamine which is selected from the following structure (VIII) (R ⁹ and R ¹⁰ are each independently selected from a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group, R ¹¹ is an ether bond or a methylene group, and a represents an integer of 1 to 4) or the following structure (IX) (wherein R ¹³ and R ¹⁴ are each independently an alkylene group having 1 to 3 carbon atoms, and Y ¹ and Y ² are each independently a single bond, -O-, -S- or an ester bond, and Z is an oxygen atom. Or a divalent organic group of a sulfur atom). The liquid crystal alignment agent of the first aspect of the invention, wherein the polyamine composition consisting of the unit structure represented by the above formula (I) and the unit structure represented by the formula (II) The content ratio of the proline component is 2:8 to 7:3 in terms of mass ratio. The liquid crystal alignment agent of claim 1 or 2, wherein R ³ in the above formula (I) is 1,3-bis(4-aminophenoxy)benzene or 1,5-double a divalent organic group of (4-aminophenoxy)pentane. The liquid crystal alignment agent according to any one of claims 1 to 3, wherein R ⁴ in the above formula (II) is a diaminodiphenyl ether, a diaminodiphenylmethane or a double The organic group of (4-aminophenethyl)urea. The liquid crystal alignment agent according to any one of claims 1 to 4, wherein R ¹ in the above formula (I) is an organic group of a pyrocholic acid, and R ² in the above formula (II) It may constitute an organic group of a cyclobutane tetracarboxylic acid. A liquid crystal alignment film obtained by applying a liquid crystal alignment agent according to any one of claims 1 to 5 to a substrate, baking, and then performing a rubbing treatment. A liquid crystal display element which is obtained by applying a liquid crystal alignment agent according to any one of claims 1 to 5 to a substrate, and performing a rubbing treatment after firing.