WO2005052028A1

WO2005052028A1 - Liquid crystal alignment treating agent for vertical alignment and liquid crystal display

Info

Publication number: WO2005052028A1
Application number: PCT/JP2004/017606
Authority: WO
Inventors: Tetsuya Imamura; Mitsumasa Kondo
Original assignee: Nissan Chemical Industries, Ltd.
Priority date: 2003-11-26
Filing date: 2004-11-26
Publication date: 2005-06-09
Also published as: KR101148812B1; TW200527081A; CN100427529C; TWI367228B; KR20060123178A; JPWO2005052028A1; JP4605016B2; CN1871279A

Abstract

A liquid crystal alignment treating agent for vertical alignment with which a liquid crystal alignment layer for vertical alignment excelling in aging resistance and voltage retention performance at high temperature can be prepared; and a liquid crystal display capable of high-quality displaying being stable over a prolonged period of time. There is provided a liquid crystal alignment treating agent for vertical alignment, comprising at least either one polymer among a polyamic acid obtained by reaction of a diamine of given structure containing an aromatic ring, a diamine of given structure containing an aromatic ring and a carbon to carbon unsaturated bond and a tetracarboxylic acid dianhydride containing an alicyclic structure and a polymer resulting from dehydration ring closure of the polyamic acid. There is further provided a liquid crystal display obtained with the use of the liquid crystal alignment treating agent.

Description

Specification

Liquid crystal alignment agent for vertical alignment and liquid crystal display device

Technical field

The present invention relates to a liquid crystal alignment treatment agent used for forming a liquid crystal alignment film of a vertical alignment type liquid crystal display element, and a liquid crystal display element manufactured using the same. Background art

[0002] The basic structure of a liquid crystal display element is a structure in which a liquid crystal material is filled between two opposing substrates, and the liquid crystal material has a desired initial alignment state by the action of a liquid crystal alignment film provided on the substrate surface. Have maintained. As this liquid crystal alignment film, a polyimide resin film having excellent heat resistance has been mainly used, and it has realized vertical alignment and horizontal alignment with respect to a substrate. As means for realizing vertical alignment, a method of introducing a long alkyl chain into polyamic acid or polyimide (for example, see Patent Document 1) and a method of introducing a cyclic substituent (for example, see Patent Documents 2 and 3) are known. Have been.

[0003] Vertically-aligned liquid crystal display devices have the characteristics of an ultra-wide viewing angle and a high contrast with a fast response speed, and new vertical-alignment-type liquid crystal display devices such as MVA, ASV, and PVA have been proposed. I have. As a driving method of these liquid crystal display elements, a matrix display in which electrodes are formed in a display pattern such as a stripe or a grid on a substrate has been known. As the liquid crystal display device, a thin film transistor (TFT) liquid crystal display device having high definition and low power consumption is used. Applications of these vertical alignment type liquid crystal display devices include conventional monitors for computers and mobile devices, but recently they have also been developed for television applications that require long-term reliability.

[0004] As one of the indexes indicating the reliability of a TFT liquid crystal display element irrespective of the alignment method, a characteristic obtained by a simple liquid crystal cell called a voltage holding ratio is known. As a means for improving the voltage holding characteristics, attempts have been made to use the structural strength of polyimide resins, and it is known that a high voltage holding ratio can be obtained by using an acid dianhydride having an aliphatic cyclic structure. It is known (see, for example, Patent Documents 4, 5, and 6). [0005] However, these are techniques for increasing the voltage holding ratio at high temperatures, and have a high voltage holding ratio at high temperatures and stabilize the voltage holding ratio against high-temperature aging which is an index indicating long-term reliability. The method has been reported so far.

Patent Document 1: Japanese Patent Application Laid-Open No. 6-3678

Patent Document 2: Japanese Patent Application Laid-Open No. 9-278724

Patent Document 3: JP 2001-311080 A

Patent Document 4: JP-A-5-341129

Patent Document 5: JP-A-8-169954

Patent Document 6: JP-A-11-84391

Disclosure of the invention

Problems to be solved by the invention

An object of the present invention is to provide a liquid crystal alignment agent for vertical alignment capable of forming a liquid crystal alignment film for vertical alignment having excellent voltage holding characteristics at high temperatures and excellent aging resistance at high temperatures. Another object of the present invention is to provide a liquid crystal display element capable of performing stable and high-quality display for a long period of time.

Means for solving the problem

[0007] It has been found that the above objects of the present invention can be solved by the following liquid crystal alignment treatment agent and liquid crystal display device.

1. Reaction of a diamine component having a diamine having a structure represented by the following formula (1) or a diamine having a structure represented by the following formula (2) with a tetracarboxylic dianhydride having an alicyclic structure. A liquid crystal aligning agent for vertical alignment, comprising at least one polymer of the obtained polyamic acid or the dehydrated ring-closure of the polyamic acid. [Chemical 1]

(In the formula (1), ェ represents a single bond or a divalent bonding group selected from the group consisting of ethers, esters, amides, and urethanes. X is a linear alkyl group having 8 to 20 carbon atoms. ,Also

2

Represents a monovalent organic group having an alicyclic skeleton having 414 carbon atoms. )

[Formula 2]

(In the formula (2), R represents a linear hydrocarbon group having 1 to 12 carbon atoms or a branched hydrocarbon group having 1 to 12 carbon atoms, and R represents a hydrogen atom, a line having 1 to 12 carbon atoms. Hydrocarbon group, or

2

Represents a branched hydrocarbon group having 1 to 12 carbon atoms. R and R independently represent a hydrogen atom or

3 4

Represents a tyl group. )

2. In the diamine component, the diamine having the structure represented by the formula (1) is 10 to 80 mol% and the diamine having the structure represented by the formula (2) is 20 to 90 mol%. Liquid crystal alignment agent for alignment.

3. The diamine force of the structure represented by the formula (1) 4_ [4_ (4_trans-n-heptylcyclohexyl) phenoxy 3-diaminobenzene and / or (4-trans-1n-pentylbicyclohexyl) _3 3. The liquid crystal aligning agent for vertical alignment according to the above 1 or 2, which is 5,5-diaminobenzoate.

4. The diamine force S having the structure represented by the formula (2), and the diamine having the structure represented by the following formula (3) 13. The liquid crystal aligning agent for vertical alignment according to any one of the above items 13.

[0010] [Formula 3]

5. A liquid crystal display device using the liquid crystal alignment agent for vertical alignment described in any one of the above items 1 to 4.

The invention's effect

According to the present invention, a liquid crystal alignment film for vertical alignment having excellent voltage holding characteristics at high temperatures and excellent aging resistance at high temperatures can be formed, and a high-quality display can be stably performed over a long period of time. Thus, a liquid crystal display device capable of performing the above operation is obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

The vertical alignment type liquid crystal aligning agent of the present invention has a diamine component having a diamine having a structure represented by the formula (1) and a diamine having a structure represented by the formula (2), and an alicyclic structure. It is a liquid crystal aligning agent for vertical alignment containing at least one of a polyamic acid obtained by reacting with tetracarboxylic dianhydride and a dehydrated ring-closed product of the polyamic acid.

Diamine having a structure represented by the formula (1) is used for imparting vertical alignment to a liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention. The amount used is preferably at least 10 mol% of the total diamine component used in the reaction to obtain the polyamic acid, and is preferably at least 20 mol%, particularly preferably at least 30 mol%, in order to secure the stability of vertical alignment. It is. [0014] Also, from the relationship with the preferred amount of diamine having a structure represented by the formula (2) described later, 80 mol. / _o or less, more preferably 70 mol% or less. Further, from the viewpoint of printability when the liquid crystal alignment treatment agent of the present invention is used as a coating solution, the content is preferably 60 mol% or less.

In the formula (1), X is a single bond or an ether, ester, amide, or urethane

1

Represents a divalent linking group selected from the group consisting of: Of these, ethers, esters and amides are preferred. Further, a diamine represented by the formula (1) wherein X is different can be used in combination.

In the formula (1), X is a linear alkyl group having 8 to 20 carbon atoms, or X

It represents a monovalent organic group having 240 alicyclic skeletons. The straight-chain alkyl group preferably has 12 to 18 carbon atoms, and more preferably 16 to 18 carbon atoms. The alicyclic skeleton having 414 carbon atoms includes monocyclic skeletons such as cyclobutane, cyclopentane and cyclohexane, skeletons combining two or more of these single rings, and steroids such as cholesterol and cholestanol. And a skeleton. The monovalent organic group having an alicyclic skeleton preferably has at least one alkyl group having 5 to 12 carbon atoms.

In the formula (1), the preferred position of the two amino groups is X, 2,2 on the benzene ring.

1

It is the position of 4, the position of 2,5, or the position of 3,5.

[0017] Specific examples of the diamine having the structure represented by the formula (1) are shown below, but are not limited thereto. Diamines having an alkyl group such as 1,3-diamino_4-octadecyloxybenzene, 1,3-diamino_4_hexadecyloxybenzene, and 1,3-diamino_4-dodecyloxybenzene. 4— [4— (4-trans-n_heptylcyclohexyl) phenoxy] —1,3-diaminobenzene, (4-trans_n_pentylbicyclohexyl) _3,5-diaminobenzoate, etc. Diamine having a structure in a side chain. A diamine having a steroid structure represented by the following formula (4)-(6). [0018] [Formula 4]

[0019] [Formula 5]

(Five)

[0020] [Formula 6]

Among the above diamines, 4_ [4_ (4_trans-n-heptylcyclohexyl) phenoxy 3-diaminobenzene, (4-trans-n-pentylbicyclohexyl) -3,5-diaminobenzoate and other liquid crystal-like structures are used as side chains. Is preferred because of excellent stability of vertical alignment.

Diamine having a structure represented by the formula (2) is used for imparting stability to aging of a voltage holding ratio, and is characterized by having an N-arylaniline structure. The use amount is preferably 20 mol% or more, more preferably 30 mol% or more of the whole diamine component used in the reaction for obtaining polyamic acid.

[0022] Also, from the relationship with the preferred amount of diamine having the structure represented by the formula (1) described above,

, Preferably 90 mol% or less, more preferably 80 mol% or less,

Omol% or less is preferable.

In the formula (2), the preferred position of the two amino groups is the 2,4 position, the 2,5 position, or the 3,5 position on the benzene ring with respect to the N-aryl group.

[0023] In the formula (2), R has 1 carbon atom.

Represents a linear hydrocarbon group having 1 to 12 carbon atoms or a branched hydrocarbon group having 1 to 12 carbon atoms. The hydrocarbon group preferably contains a carbon-carbon double bond, more preferably the double bond is between the second and third carbon atoms from the nitrogen atom. The carbon number of R is 6 or less from the viewpoint of printability of the liquid crystal alignment agent. It is preferably 3 or less, more preferably 3 or less.

In the formula (2), R is a hydrogen atom, a linear hydrocarbon group having 1 to 12 carbon atoms, or a carbon atom.

2

Represents a branched hydrocarbon group represented by the following formula: This hydrocarbon group may contain a carbon-carbon double bond. Also, the carbon number of R is preferably 6 or less, more preferably

2

In particular, R is a hydrogen atom.

2

In the formula (2), R and R are each independently a hydrogen atom or a force representing a methyl group.

3 4

Is more preferable.

A preferred example of the diamine having the structure represented by the formula (2) is, for example, the structure of the following formula (3).

[0026] [Formula 7]

Specific examples of the diamine having the structure represented by the formula (2) are shown below, but are not limited thereto.

[0027] [Formula 8]

H ₂ N- -N (7) [0028]

[0029] [Formula 10]

[0030] [Formula 11]

[0031] [Formula 12]

Among the above diamines, the diamine of (7) or (8) is particularly preferred.

The diamine component of the present invention, which requires the diamine having the structure represented by the above formula (1) and the diamine having the structure represented by the above formula (2), has printing characteristics of the liquid crystal alignment treatment agent and residue of the liquid crystal cell. Other diamines may be included for the purpose of controlling various characteristics such as static DC voltage characteristics. The amount of the other diamine to be used is preferably 70 mol% or less, more preferably 60 mol% or less, and particularly preferably 40 to 10 mol ° / of the entire diamine component used in the reaction for obtaining the polyamic acid. Is preferred.

[0033] Such diamines are not particularly limited, but specific examples include p_phenylenediamine, m-phenylenediamine, 2,5-diaminobenzonitrile, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, diaminodiphenylmethane, diamino Diphenyl ether, diaminodiphenylamine, 2,2'-diaminodiphenylpropane, bis (3,5-ethylamino-4-aminophenyl) methane, diaminodiphenylsulfone, diaminobenzophenone, 3,3,- Diaminochalcone, 4,4, -diaminochalcone, 3,3, diaminostilbene, 4,4,1-diaminostilbene, diaminonaphthalene, 1,4_bis (4-amino Phenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 1,3-bis (4-aminophenoxy) benzene, 4,4'-bis (4- Aminophenyl) diphenylsulfone, 2,2-bis [4 -— (4-aminophenoxy) phenyl] propane, 2,2_bis (4-aminophenyl) hexafluoropropane, 2,2_bis [4— Aromatic diamines such as (4-aminophenol) phenyl] hexafluoropropane, 2,6-diaminopyridine, 2,4-diaminopyridine, 2,7-diaminobenzofuran, 2,7-diaminocarbazole, 3 2,7-diaminophenothiazine, 2,5-diamino_1,3,4-thiadiazole, 2,4_diamino_s-triazine, and other heterocyclic diamines, bis (4-aminocyclohexyl) methane, Alicyclic Jiamin and 1, such as methane - ₍₄ Amino _3- hexyl methylcyclohexyl), 2-di § Minoetan, 1, 3-Jiaminopuropan, 1, 4-diaminobutane, 1, aliphatic, such as hexane 6- Jiamino Diamine and silicon diamine such as 1,3-bis (3-aminopropyl) -1,1,1,3,3-tetramethyldisiloxane.

[0034] <Tetracarboxylic dianhydride having an alicyclic structure>

Examples of tetracarboxylic dianhydrides having an alicyclic structure include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexane Hexanetetracarboxylic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarbo Xy 1,2,3,4-tetrahydro_1_naphthalene succinic acid, bicyclo [3,3,0] octane-1,2,4,6,8-tetracarboxylic acid and the like, but not limited thereto. Further, two or more of these tetracarboxylic dianhydrides may be copolymerized. From the viewpoint of polymerization reactivity with the diamine component, 1,2,3,4-cyclobutanetetracarboxylic acid is preferred.

The polyamic acid in the present invention comprises a diamine component containing a diamine having a structure represented by the formula (1) and a diamine component having a structure represented by the formula (2), and a tetracarboxylic dianhydride component having an alicyclic structure. It is obtained by reacting. The diamine component and the tetracarboxylic dianhydride component are reacted by supplying the former at a ratio of preferably 0.91 to 11 mol, particularly 0.95 to 1.05 mol, with respect to the former lmol.

[0036] The polyamic acid synthesis reaction is carried out in an organic solvent at a reaction temperature of usually 0 to 150 ° C, preferably 0 to 100 ° C. The organic solvent at this time is not particularly limited as long as the obtained polyamic acid can be dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, Examples thereof include dimethyl sulfone, hexamethylsulfoxide, and γ-petit ratatatone. These may be used alone or as a mixture. Further, even if the solvent does not dissolve the polyamic acid, it may be used by mixing with the above solvent as long as the polyamic acid generated by the polymerization reaction does not precipitate.

[0037] The polyamic acid used in the liquid crystal alignment treatment agent of the present invention has a weight average molecular weight {Mw} measured by GPC (Gel Permeation Chromatography) method of preferably 21,500,000, particularly preferably 51,200,000. It is preferred to do so. If the molecular weight is too small, the strength of the coating film obtained therefrom will be insufficient, and if the molecular weight is too large, the workability at the time of forming the coating film may deteriorate. The molecular weight of the polyamic acid can be controlled by adjusting the molar ratio of the diamine component and the tetracarboxylic dianhydride used in the synthesis reaction of the polyamic acid. As in the ordinary polycondensation reaction, the closer the molar ratio is to 1.0, the higher the degree of polymerization of the produced polymer becomes.

<Dehydrated ring closure of polyamic acid> Examples of the dehydrated ring-closure of polyamic acid include polyimide. In addition, the dehydrated ring-closure of polyamic acid referred to herein includes those in which all of the repeating units of the polyamic acid are not dehydrated and ring-closed, but is included in the category, and is also suitable for the liquid crystal alignment treatment agent of the present invention. Used.

Usually, imidation (dehydration ring closure) of a polyamic acid can be performed in a solution. In the method of imidizing a polyamic acid in a solution, the reaction temperature is usually 50 to 200 ° C, preferably 60 to 170 ° C. If the reaction temperature is lower than 50 ° C, the dehydration ring-closing reaction does not proceed sufficiently, and if the reaction temperature is higher than 200 ° C, the molecular weight of the obtained imidized polymer is reduced. It is preferable to add a dehydrating agent and / or a dehydration ring-closing catalyst during the imidation reaction, since the imidization reaction proceeds at a relatively low temperature and a decrease in the molecular weight of the resulting polyimide hardly occurs. As the dehydrating agent, for example, acid anhydrides such as acetic anhydride and propionic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the repeating unit of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine and triethylamine can be used. The use amount of the dehydration ring-closing catalyst is preferably 0.01 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the dehydration ring closure reaction, the organic solvents exemplified as those used for the synthesis of polyamic acid can be exemplified. The reaction temperature when a dehydrating agent and / or a dehydration ring-closing catalyst is added is usually 0 to 180 ° C, preferably 10 to 150 ° C.

[0040] The polyamic acid or polyimide obtained as described above can be used as it is. Alternatively, it can be used after precipitation and isolation in a poor solvent such as methanol or ethanol.

The liquid crystal alignment treatment agent of the present invention contains at least one polymer of the above-mentioned polyamic acid having a specific structure or a dehydrated ring-closure of the polyamide acid, and is usually used in the form of a coating solution. Can be The solvent contained in the coating solution is not particularly limited as long as it can dissolve the above-mentioned polymer component. These can be used alone or in combination of two or more solvents. Furthermore, the polymer alone dissolves Even if there is no solvent, it can be added as long as the polymer component does not precipitate. The solid content concentration of the coating solution can be set to an arbitrary value according to the coating device to be used and the thickness of the liquid crystal alignment film to be obtained. About 110% by weight is appropriate.

Hereinafter, specific examples of the solvent component contained in the coating liquid are shown, but are not limited thereto.

[0042] N_methyl_2_pyrrolidone, Ν, Ν-dimethylformamide, Ν, Ν-dimethylacetoamide, γ_butyrolataton, dimethylsulfoxide, tetramethylurea, hexamethylphosphotriamide, m-cresol, methyl alcohol, Ethyl alcohol, getyl ether, ethylene glycol monomethyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, and the like.

[0043] The polymer component contained in the liquid crystal alignment treatment agent of the present invention may be any of those described above for the purpose of controlling various characteristics such as printing characteristics of the liquid crystal alignment treatment agent and residual DC voltage characteristics of the liquid crystal cell. In addition to the polyamic acid having the specific structure described above and / or its dehydrated ring-closure, a polymer having a different structure from the polymer having the specific structure may be mixed. This polymer having another structure is preferably 95% by weight or less, particularly preferably 90 to 10% by weight, based on the entire polymer component contained in the liquid crystal alignment treatment agent of the present invention.

Examples of the polymer having another structure include one or more tetracarboxylic dianhydrides selected from the following tetracarboxylic dianhydrides and diamine compounds, and one or more diamine dianhydrides. Polyamic acid and its dehydrated ring-closed product obtained by the reaction with a product, but are not limited thereto.

[0045] Tetracarboxylic dianhydride: pyromellitic acid, 2,3,6,7_naphthalenetetracarboxylic acid, 1,2,5,6_naphthalenetetracarboxylic acid, 1,4,5,8_naphthalenetetra Carboxylic acid, 2,3,6,7_anthracenetetracarboxylic acid, 1,2,5,6_anthracenetetracarboxylic acid, 3,3,4,4'-biphenyltetracarboxylic acid, 2,3, 3,, 4-biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3'4,4'-benzophenonetetracarboxylic acid, 3,3'4,4'_chalconetetra Carboxylic acid, bis (3,4-dicarboxy Phenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-dicanololeboxyphenyl) propane, 1,1,1,3,3,3_hexafluoro-2,2 _Bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5_pyridinetetracarboxylic Acid, 2,6-bis (3,4-dicarboxyphenyl) pyridine and other aromatic tetracarboxylic dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4 —Cyclopentane tetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 2,3,5 tricanoleoxycyclopentyl acetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro—1_naphthale Succinic acid, bicyclo [3, 3 [0,0] octane 2,4,6,8-tetracarboxylic acid and other alicyclic tetracarboxylic dianhydrides, 1,2,3,4 butanetetracarboxylic acid and other dianhydrides Things.

Diamine compounds: p-phenylenediamine, m-phenylenediamine, 2,4-diamino-N, N-diallylaniline, 2,5-diaminobenzonitrile, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4 , -Diaminobiphenyl, 3,3, -dimethyl-4,4, -diaminobiphenyl, 3,3,1-dimethoxy-4,4, diaminobiphenyl, diaminodiphenylmethane, diaminodiphenylether, diaminodiphenyl 2,2'-diaminodiphenylpropane, bis (3,5-ethylamino-4-phenylamino) methane, diaminodiphenylsulfone, diaminobenzophenone, 3,3'-diaminochalcone, 4,4'-diaminochalcone, 3, 3'-diaminostilbene, 4, 4'-diaminostilbene, diaminonaphthalene, 1,4_bis (4-aminophenoxy) ben 1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 1,3-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophen) Nonoxy) diphenylsulfone, 2,2_bis [4 -— (4-aminophenoxy) phenyl] propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4— ( Aromatic diamines such as 4-aminophenyl) phenylhexafluoropropane, 2,6-diaminopyridin, 2,4-diaminopyridine, 2,7-diaminobenzofuran, 2,7-diaminocarbazole, 3 2,7-diaminophenothiazine, 2,5-diamino-1,3,4-thiadiazonole, 2,4-diamino-s-triazine and other heterocyclic diamines, bis (4-aminocyclohexyl) methane , Screws (4— Alicyclic Jiamin and 1 amino _3- methylcyclohexyl cyclohexyl) methane, 2- Jiaminoe Aliphatic diamines such as tan, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,3-diamino-4-octadecyloxybenzene, 1,3-diamino 4-Hexadecyloxybenzene, 1,3-diamino_4-Dodecyloxybenzene, 4_ [4_ (4_trans-n-heptylcyclohexyl) phenoxy] -1,3-diaminobenzene, (4-trans Diamines with alkyl groups such as n-pentylbicyclohexyl) -3,5-diaminobenzoate and liquid crystal-like structures in the side chain, 1,3_bis (3-aminopropyl) -1,1,3,3-tetra Silicon diamine such as methyldisiloxane.

The liquid crystal alignment treatment agent of the present invention may contain a functional silane-containing compound for imparting adhesion to a substrate. For example, N-trimethylsilylacetamide, diacetoxydimethylsilane, tetramethoxysilane, 3-aminopropyljetoxymethylsilane, 3-aminopropyltriethoxysilane, 1,4-bis (dimethylsilyl) benzene, bis (dimethylamino) dimethyl Examples thereof include, but are not limited to, silane, bis (ethylamino) dimethylsilane, 1-trimethylsilylimidazole, methyltriacetoxysilane, ethoxymethylphenylsilane, phenyltriethoxysilane, and diphenylsilanediol.

The liquid crystal alignment treating agent of the present invention can be applied to a substrate and then dried and baked to form a liquid crystal alignment film for vertical alignment.

As a method of applying the liquid crystal alignment treatment agent, a spin coating method, a printing method, an ink jet method, etc. may be mentioned. From the viewpoint of power productivity, the transfer printing method is widely used industrially. It is also suitably used in agents.

[0049] The drying step after the application of the liquid crystal alignment treatment agent is not necessarily required, but the time from application to one baking is not constant for each substrate, or baking is not performed immediately after the application. In this case, it is preferable to include a drying step. The drying means is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coating film is not deformed by the transport of the substrate or the like. As a specific example, a method of drying on a hot plate at 50 to 150 ° C., preferably 80 to 120 ° C., for 0.5 to 30 minutes, preferably 115 minutes may be employed.

[0050] The firing of the liquid crystal alignment treatment agent can be performed at an arbitrary temperature of 100 to 350 ° C, preferably 150. C-1 300. C, and even more preferred is 200. C-250. C. Liquid crystal alignment treatment When the polyamic acid is contained in the agent, the conversion rate from polyamic acid to polyimide changes depending on the calcination temperature, but the liquid crystal alignment treatment agent of the present invention does not necessarily need to be imidized at 100%. However, it is preferable that the baking is performed at a temperature higher by 10 ° C. or more than a heat treatment temperature required for a liquid crystal cell manufacturing process, such as curing of a sealant, regardless of whether polyamic acid is contained.

If the thickness of the coating film after baking is too large, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be reduced, so that the thickness is 5 to 300 nm, preferably 10 to 100 nm. Oh.

The liquid crystal display device of the present invention is obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal alignment agent of the present invention by the above-described method, and then forming a liquid crystal cell by a known method to obtain a liquid crystal display device. To give an example of liquid crystal cell production, a pair of substrates on which a liquid crystal alignment film is formed is fixed with a sealant with a spacer of 30 μπι, preferably 2-10 μπι, A method of injecting a liquid crystal and sealing is common. The method of sealing the liquid crystal is not particularly limited, and examples thereof include a vacuum method in which the pressure in the manufactured liquid crystal cell is reduced and then the liquid crystal is injected, and a dropping method in which the liquid crystal is dropped and then sealed.

[0052] The substrate used for the liquid crystal display element is not particularly limited as long as it is a substrate having high transparency, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. Among them, it is preferable to use a substrate on which a negative electrode or the like for driving a liquid crystal is formed from the viewpoint of simplifying the process. In the case of a reflection type liquid crystal display device, an opaque material such as a silicon wafer can be used as long as only one substrate is used. In this case, a material which reflects light such as aluminum can be used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example

12.20 g (0.06 mol) of 2,4-diamino-Ν, Ν-dialinoleadiline represented by the above formula (7) and 4_ [4_ (4_trans-1-n-heptylcyclohexyl) phenoxy 3-diamino Benze 15.22 g (0.04 mol) of N-methinole-2-pyrrolidone (hereinafter abbreviated as NMP) was melted into 187.3 g, and this (1,2,3,4,1-cyclobutanetetranolevonic acid) After adding 19.41 g (0.099 mol) of dianhydride and reacting at room temperature for 24 hours, a solution of polyamic acid was obtained, and the weight average molecular weight {Mw} of the obtained polyamic acid was 40,000. the solution 30g of added NMP50g and E Ji glycol _ _n _ ether 20g, and a uniform solution thoroughly stirred to obtain a liquid crystal alignment treating agent at a concentration 6 wt% of the present invention.

This liquid crystal alignment treatment agent was subjected to pressure filtration with a membrane filter having a pore size of 0.5 μm, and then spin-coated on a glass substrate with a transparent electrode. The substrate was placed on a hot plate at 80 ° C., dried for 5 minutes, and baked in a hot air circulating oven at 210 ° C. for 60 minutes to obtain a 100 nm thick liquid crystal alignment film on the substrate.

[0055] Two substrates with a liquid crystal alignment film were prepared, and a 6-μm spacer was sprayed on the liquid crystal alignment film surface of one of the substrates. MLC-6608) was injected to prepare a liquid crystal cell. Observation of the alignment state of the liquid crystal with a polarizing microscope confirmed that the liquid crystal had a uniform vertical alignment without defects.

[0056] The liquid crystal cell was placed in a constant temperature bath at 80 ° C, and a voltage of ± 4 V, a pulse width of 0.06 ms and a frame of The voltage holding ratio was measured by the voltage ratio under the condition of a period of 16.67 ms. As a result, the voltage holding ratio at 80 ° C showed a very high value of 97.9%. Further, after aging treatment of this liquid crystal cell at 120 ° C for one week, the voltage holding ratio at 80 ° C was measured again in the same manner, and it was found that the voltage holding ratio was as high as 94.1%. Was. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

19.83 g (0.1 mol) of 4,4,1-diaminodipheninolemethane was dissolved in 228.6 g of NNP, and 10.91 g (0.05 mol) of pyromellitic dianhydride and 1, 2, 3, 9.61 g (0.049 mol) of 4, -cyclobutanetetracarboxylic acid dianhydride was added thereto, and the mixture was reacted at room temperature for 24 hours to obtain a polyamic acid solution. The weight average molecular weight {Mw} of the obtained polyamic acid was 65,000. To 40 g of this solution, 40 g of NMP and 20 g of ethylene glycol butyl n-butyl ether were added, and the mixture was sufficiently stirred to obtain a uniform solution having a concentration of 6 wt%. Next, the polyamic acid solution with this concentration of 6 wt% After mixing 40 g of the liquid and the liquid crystal aligning agent lOg prepared in Example 1, the mixture was sufficiently stirred to obtain a liquid crystal aligning agent of the present invention as a uniform solution.

This liquid crystal alignment treatment agent was subjected to the same treatment as in Example 1 to produce a liquid crystal cell. Observation of the alignment state of the liquid crystal with a polarizing microscope confirmed that the liquid crystal had a uniform vertical alignment without any defects.

The voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very high value of 97.7%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for one week maintained a very high value of 96.1%. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

4,4,1-Diaminodipheninoleatenole 20.02 g (0.1 mol) is added to NMP 253.8 g (the melting angle is increased, and bicyclo [3,3,0] octane—2,4,6,8— 24.77 g (0.099 mol) of tetracarboxylic dianhydride was added and reacted at room temperature for 24 hours to obtain a polyamic acid solution. The weight average molecular weight {Mw} of the obtained polyamic acid was 36,000. To 30 g of this solution, 50 g of NMP and 20 g of ethylene glycol mono- _n -butyl ether were added to obtain a solution having a concentration of 6 wt%, and sufficiently stirred to obtain a uniform solution. Next, 40 g of the polyamic acid solution having a concentration of 6 wt% and 10 g of the liquid crystal aligning agent obtained in Example 1 were mixed, and sufficiently stirred to obtain a liquid crystal aligning agent of the present invention as a uniform solution.

This liquid crystal alignment agent was subjected to the same treatment as in Example 1 to produce a liquid crystal cell. Observation of the alignment state of the liquid crystal with a polarizing microscope confirmed that the liquid crystal had a uniform vertical alignment without any defects.

The voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very high value of 97.9%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for one week maintained a very high value of 95.5%. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

<Example 4> 12.20 g (0.06 mol) of 2,4-diamino-N, N-dialinoleadiline represented by the formula (7) and 15.07 g (0,0) of 1,3-diamino-14-octadecyloxybenzene O4mol) was added with NMP186.7g (the melting angle ratio, this (1,2,3,4, -cyclobutanetetranorenoleic acid dianhydride 19.41g (0.099mol)) was added, and the mixture was allowed to stand at room temperature for 24 hours. reacted to obtain a solution of polyamic acid. the weight average molecular weight of the obtained polyamic acid {Mw} was 44000. the solution 30g added NMP50g and ethylene glycol _ _n _ ether 20g to sufficiently stirred to uniformly Thus, a liquid crystal alignment treating agent of the present invention having a concentration of 6 wt% was obtained.

The voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very high value of 96.4%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for one week maintained a very high value of 92.2%. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

12.20 g (0.06 mol) of 2,4-diamino-N, N-dialinoleadiline represented by the formula (7) and 4_ [4_ (4-trans-n-heptylcyclohexyl) phenoxy] _1, 15.22 g (0.04 mol) of 3-diaminobenzene was dissolved in NMP187.3gi, and this (1,2,3,4,1-cyclobutanetetracarboxylic dianhydride 19.41 g (0.099 mol) ) Was added thereto and reacted at room temperature for 24 hours to obtain a polyamic acid solution.

[0065] In the next stage, the solution was diluted with 35.26 g of NMP, and 30.50 g of anhydrous anhydride and 13.00 g of pyridine were added thereto and reacted at 30 ° C for 4 hours. After the reaction solution was cooled to about room temperature, it was poured into methanol, and a precipitated solid was recovered. The solid was washed several times with methanol, and dried at 80 ° C. under reduced pressure to obtain a white polyimide powder. The weight average molecular weight {Mw} of the obtained polyimide was 35,000. The imidation ratio (dehydration ring closure ratio) of this polyimide was 59%. The imidation ratio was determined by 1 H-NMR measurement from the integral ratio of the remaining protons derived from the amide group and the protons derived from the methyl group. [0066] 6g of the above-obtained polyimide powder was dissolved in 74g of NMP, and 20g of ethylene glycol-n-butyl ether was further dissolved and stirred sufficiently to form a uniform solution. The liquid crystal alignment treatment of the present invention having a concentration of 6wt% was performed. Agent was obtained.

The voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very high value of 97.9%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for 1 week maintained a very high value of 93.0%. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

A polyimide powder was obtained in the same manner as in Example 5, except that the imidization condition of the polyamic acid solution was changed from 30 ° C / 4 hours to 40 ° C / 4 hours. The weight average molecular weight {Mw} of the obtained polyimide was 35,000, and the imidation ratio was 87%.

[0069] 6 g of the polyimide powder obtained above was dissolved in 74 g of NMP, and 20 g of ethylene glycol-n-butyl ether was further added thereto. The mixture was sufficiently stirred to obtain a uniform solution. Obtained.

The voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very high value of 97.8%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for one week maintained a very high value of 95.5%. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

25 g of the liquid crystal alignment treatment agent prepared in Example 6, and a concentration of 6 wt% synthesized and prepared in Example 2. Was mixed with 25 g of a polyamic acid solution of the above, and sufficiently stirred to obtain a liquid crystal orientation treating agent of the present invention as a uniform solution.

[0072] The voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very high value of 97.2%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for one week maintained a very high value of 96.8%. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

A polyimide powder was obtained in the same manner as in Example 5, except that the imidization condition of the polyamic acid solution was changed from 30 ° C / 4 hours to 50 ° C / 4 hours. The weight average molecular weight {Mw} of the obtained polyimide was 35,000, and the imidation ratio was 97%.

[0074] 6 g of the polyimide powder obtained above was dissolved in 74 g of NMP, 20 g of ethylene glycol-n-butyl ether was further added, and the mixture was sufficiently stirred to form a uniform solution. Obtained.

Further, the liquid crystal cell was evaluated for the voltage holding ratio in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very high value of 98.1%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for one week maintained a very high value of 98.1%. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

12.20 g (0.06 mol) of 2,4-diamino-N, N-dialinoleadiline represented by the above formula (7) and 4_ [4_ (4_trans-1 n-butylcyclohexyl) phenoxy 3-diaminobenze 15.22 g (0.04 mol) of NMP196.Og was dissolved in NMP196.Og, and pyromellitic dianhydride 21.59 g (0.099 mol) was added to the solution, and the mixture was reacted at room temperature for 24 hours. Was obtained. The weight average molecular weight {Mw} of the obtained polyamic acid was 44,000. To 30 g of this solution, 50 g of NMP and 20 g of ethylene glycol butyl n-butyl ether were added, and the mixture was sufficiently stirred to obtain a uniform solution. Thus, a liquid crystal alignment treatment agent having a concentration of 6 wt% for comparison was obtained.

Further, the liquid crystal cell was evaluated for the voltage holding ratio in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a very low value of 74.0%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for one week was 10.0%, which was a large decrease compared to the initial stage. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

12.20 g (0.06 mol) of 2,4-diamino-N, N-dialinoleadiline represented by the above formula (7) and 4_ [4_ (4_trans-n-butylcyclohexyl) phenoxy 3-diaminobenze 15.22 g (0.04 mol) of NMP237.3gi was melted, and this was used to prepare 31.90 g (0.099 mol) of benzo-3-phenonetetracarboxylic dianhydride. The resulting mixture was reacted at room temperature for 24 hours to obtain a polyamic acid solution. The weight average molecular weight {Mw} of the obtained polyamic acid was 48,000. To 30 g of this solution were added 50 g of NMP and 20 g of ethylene glycol butyl n-butyl ether, and the mixture was sufficiently stirred to obtain a uniform solution, thereby obtaining a liquid crystal aligning agent for comparison at a concentration of 6 wt%.

Further, the voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging showed a low value of 89.3%. Furthermore, the voltage holding ratio at 80 ° C after aging treatment at 120 ° C for 1 week is 62.1%, A large decrease was observed in comparison. In addition, when the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

Dissolve 6.49 g (0.06 mol) of p-phenylenediamine and 15.22 g (0.04 mol) of 4- [4- (4-trans-1-n-heptylcyclohexynole) phenoxy 3-diaminobenzene in 233.0 g of NMP Then, 19.41 g (0.099 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added thereto, and the mixture was reacted at room temperature for 24 hours to obtain a polyamic acid solution. The weight average molecular weight {Mw} of the obtained polyamic acid was 48,000. To 40 g of this solution, 40 g of NMP and 20 g of ethylene glycol_n_butyl ether were added, and the mixture was sufficiently stirred to obtain a uniform solution, thereby obtaining a liquid crystal alignment treatment agent for comparison at a concentration of 6 wt%.

Further, the voltage holding ratio of this liquid crystal cell was evaluated in the same manner as in Example 1. As a result, the voltage holding ratio at 80 ° C before aging was as high as 97.3%, but the voltage holding ratio at 80 ° C after aging at 120 ° C for 1 week was 87%. . 9%, which was lower than the initial level. When the alignment state of the liquid crystal after aging was observed with a polarizing microscope, it was confirmed that the liquid crystal had a uniform vertical alignment without any defect.

The results of the voltage holding ratio measurements of Example 118 and Comparative Example 13 are shown below.

[0082] [Table 1]

Voltage holding ratio at 80 ° C (%) Before aging After aging Example 1 97.9 94.9 Example 2 97.7 96.1 Example 3 97.9 95.5 Example 4 96.4 92.2 Example 5 97.9 93.0 Example 6 97.8 95.5 Example 7 97.2 96.8 Example 8 98.1 98.1 Comparative Example 1 74.0 10.0 Comparative Example 2 89.3 62.1 Comparative Example 3 97.3 87.9

Claims

Claims [1] A diamine component essentially including a diamine having a structure represented by the following formula (1) and a diamine having a structure represented by the following formula (2): and a tetracarboxylic dianhydride having an alicyclic structure. A liquid crystal aligning agent for vertical alignment, comprising at least one polymer selected from the polyamic acid obtained by the reaction and the dehydrated ring-closure of the polyamic acid. [Chemical 1]

(In the formula (1), X represents a single bond or a divalent linking group selected from the group consisting of ethers, esters, amides, and urethanes. X represents a linear alkyl group having 8 to 20 carbon atoms. ,Also

2

[Formula 2]

(In the formula (2), R represents a linear hydrocarbon group having 1 to 12 carbon atoms or a branched hydrocarbon group having 1 to 12 carbon atoms, and R represents a hydrogen atom,

It represents a linear hydrocarbon group having 2 to 12 carbon atoms or a branched hydrocarbon group having 1 to 12 carbon atoms. R and R independently represent a hydrogen atom or

3 4

Represents a tyl group. )

[2] The diamine component according to claim 1, wherein the diamine having the structure represented by the formula (1) is 10 to 80 mol%, and the diamine having the structure represented by the formula (2) is 20 to 90 mol%. Dripping Liquid crystal alignment agent for direct alignment.

[3] Diamine force of the structure represented by the formula (1) 4_ [4_ (4_trans-n-heptylcyclohexyl) phenoxy] _1,3-diaminobenzene, and Z or (4-trans-n-pentylbicyclo) 3. The liquid crystal aligning agent for vertical alignment according to claim 1, which is hexyl) -3,5-diaminobenzoate.

[4] The liquid crystal alignment treating agent for vertical alignment according to any one of [13] to [13], wherein the diamine having a structure represented by the formula (2) is a diamine having a structure represented by the following formula (3).

[Formula 3]

[5] A liquid crystal display device using the liquid crystal alignment agent for vertical alignment according to claim 14.