TWI452397B - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

Liquid crystal alignment agent and liquid crystal display element

The present invention relates to a liquid crystal alignment agent containing a compound containing oxetane. More specifically, it is a liquid crystal alignment agent which is excellent in voltage retention rate reliability showing a high voltage holding ratio.

In the liquid crystal display device, a liquid crystal alignment film made of polyacrylamide, polyimide or the like is formed on a surface of a substrate on which a transparent conductive film is provided as a substrate for a liquid crystal display, and two sheets are arranged to face each other. A nematic liquid crystal layer having a positive dielectric anisotropy is formed in the gap as a cell having a sandwich structure, and the long axis having liquid crystal molecules is continuously twisted by 90 degrees from one substrate to the other substrate. A TN type liquid crystal display element of a TN (Twisted Neumatic) type liquid crystal cell is known.

Further, an STN (Super Twisted Nematic) liquid crystal display element having a higher contrast than a TN type liquid crystal display element and having a small viewing angle dependency has been developed. The STN-type liquid crystal display device is a liquid crystal obtained by incorporating a chiral agent containing an optically active substance into a nematic liquid, and the long axis of the liquid crystal molecule is continuously twisted by 180 degrees or more between the substrates. The state is the one that utilizes the birefringence effect produced by it.

Moreover, in recent years, the development of new liquid crystal display elements is also booming, one of which is that the two electrodes for driving the liquid crystal are arranged in a comb shape. A lateral electric field type liquid crystal display element which generates an electric field parallel to the substrate surface to control liquid crystal molecules on one side of the substrate has been proposed (refer to Japanese Laid-Open Patent Publication No. Hei 7-261181). This component is commonly referred to as the In Plane Switching type (referred to as the IPS type), and it is well known that it has a wide viewing angle characteristic. Further, recently, by using an optical compensation film to further improve the wide viewing angle characteristics, it is possible to obtain a wide viewing angle comparable to that of a Brown tube without occurrence of gradation inversion and hue change, which is a significant feature.

A liquid crystal display element other than the above has been proposed as a MVA (Multi Domain Vertical Alignment) method and a PVA in which a liquid crystal molecule having a negative dielectric anisotropy is aligned perpendicular to a substrate. (Patterned Vertical Alignment) vertical alignment type liquid crystal display element. The liquid crystal display elements of the MVA method and the PVA method are excellent not only in viewing angle and contrast, but also in the formation of the liquid crystal alignment film without rubbing treatment, and are also excellent in process.

These liquid crystal display elements are also used in televisions and information boards, and the like, because panel reliability requirements such as electrical characteristics that do not change after a long period of use are more severe.

An object of the present invention is to provide a liquid crystal alignment agent excellent in reliability of a high voltage holding ratio and a voltage holding ratio, and a liquid crystal display element including the liquid crystal alignment agent formed thereby.

Still another object and advantage of the present invention will be understood from the following description. According to the present invention, the above objects and advantages of the present invention can be attained by a liquid crystal alignment agent characterized in that: (A) a polymerization obtained by reacting a tetracarboxylic dianhydride and a diamine compound Proline and/or its ruthenium iodide polymer, and (B-1) a compound having two or more oxetane rings in the molecule, or (B-2) having 2 in the molecule A combination of a compound having more than one epoxy group and a compound having two or more oxetane rings in the molecule.

Hereinafter, the present invention will be described in detail.

[Compound with two or more oxetane rings in the molecule]

In the present invention, 100 parts by weight of the ruthenium imidized polymer obtained by reacting the polyamic acid obtained by reacting the tetracarboxylic dianhydride with the diamine compound and/or the polyamic acid by hydrazine is used in the molecule. The compound having two or more oxetane rings may be used in an amount of 0.01 to 100 parts by weight. Further, since the reaction of the oxetane compound can be accelerated by adding an epoxy compound having a fast reaction initiation, the compound having two or more oxetane rings in the molecule and two or more epoxy groups in the molecule The total amount of the compound can also be used in an amount of 0.01 to 100 parts by weight. The compound having two or more oxetane rings in the molecule is preferably a compound represented by the following formulas (A), (B) and (C). The compound represented by the following formula (A) is a compound having two or more oxetane rings in the molecule. (wherein, Ra is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Rb is an organic group having 1 to 20 carbon atoms, and 1 is 0 or 1)

Preferably, in the above (a), Ra is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Rb is a linear or branched saturated hydrocarbon group having a carbon number of 1 to 20 and a linear number of carbon atoms of 1 to 20. Or a branched unsaturated hydrocarbon group, a phenylene group, a linear or branched polyol having 1 to 20 carbon atoms, an aromatic group having a nitrogen atom, a carboxyl group, or a selected one of the following formulas (I) and (II) And an aromatic hydrocarbon group represented by (III), (IV), (V) and (VI), and a divalent group of the aromatic hydrocarbon group of the carboxyl group represented by the following formula (VII) (VIII);

In the above formula, h represents an integer of 1 to 6, Re is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aromatic group or an aralkyl group, and Rf represents -O-, -S-, -CH ₂ -, - NH-, -SO ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, or -C(CF ₃ ) ₂ -, the plural Rg may be the same or different, respectively representing a hydrogen atom or An alkyl group having 1 to 6 carbon atoms.

The compound having three or more oxetane rings in the molecule can be represented by the following formulas (B) and (C), respectively.

In the above formula (B), the Ra system has the same meaning as described above, and Rc is an n-valent organic group, and preferably has a carbon number of 1 to 12 as shown by the following formulas (XI) and (XII). a branched alkylene group having a linear or branched polyoxyalkylene group as shown by (XIII) or (XIV), a linear or branched polyol having 1 to 12 carbon atoms. . Further, n represents the number of functional groups bonded to the residue Rc, and is an integer of 3 or more, preferably an integer of 3 to 5,000.

In the above formula (XI), k is an integer of 1 to 3.

The compound represented by the following formula (C) may have 4 to 22 oxetane rings.

In the above formula (C), Rd is a divalent organic group, and is an alkyl silyl having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group (here, The alkyl group may be the same or different alkyl group having 3 to 12 carbon atoms, and the trialkylsulfanyl group may, for example, be a trimethylsulfanyl group, a triethylsulfanyl group, a tripropyldecylalkyl group or a tributyldecane. It is preferable that m is an integer of 1 to 10.

Examples of such a compound having two or more oxetane rings in the molecule represented by the above formulas (A), (B) and (C) include, for example, 1,4-double {[(3) -ethyl-3-oxetanyl)methoxy]methyl}benzene (Alon oxetane OXT-121 (XDO)), bis[2-(3-oxetane) Butyl]ether (Alon oxetane OXT-221 (DOX)), 1,4-bis[(3-ethyloxetane-3-indenyl)methoxy]benzene (HQOX) , 1,3-bis[(3-ethyloxetane-3-indenyl)methoxy]benzene (RSOX), 1,2-bis[(3-ethyloxetane-3) -mercapto)methoxy]benzene (CTOX), 4,4'-bis[(3-ethyloxetane-3-indenyl)methoxy]biphenyl (4,4'-BPOX) , 2,2'-bis[(3-ethyl-3-oxetanyl)methoxy]biphenyl (2,2'-BPOX), 3,3',5,5'-tetra [4,4'-bis[(3-ethyloxetan-3-yl)methoxy]biphenyl (TM-BPOX), 2,7-bis[(3-ethyloxa) Cyclobutane-3-indenyl)methoxy]naphthalene (2,7-NpDOX), 1,6-bis[(3-ethyloxetane-3-indenyl)methoxy]-2 , 2,3,3,4,4,5,5-octafluorohexane (OFH-DOX), 3 (4), 8 (9)-bis[(1-ethyl-3-oxetane) yl) methoxymethyl] tricyclo [5.2.1.0 ^2.6] decane, 4,4'-bis [(1- Benzyl-3-oxetanyl)methyl]thiodiphenyl sulfide, 2,3-bis[(3-ethyloxetane-3-indenyl)methoxymethyl]norborn Alkane (NDMOX), 2-ethyl-2-[(3-ethyloxetan-3-indolyl)methoxymethyl]-1,3-O-bis[(1-ethyl-3) -oxetanyl)methyl]-propane-1,3-diol (TMPTOX), 2,2-dimethyl-1,3-O-bis[(3-ethyloxetane) -3-mercapto)methyl]-propane-1,3-diol (NPGOX), 2-butyl-2-ethyl-1,3-O-bis[(3-ethyloxetane) -3-mercapto)methyl]-propane-1,3-diol, 1,4-o-bis[(3-ethyloxetane-3-indenyl)methyl]-butane- 1,4-diol, 2,4,6-o-tris[(3-ethyloxetan-3-indolyl)methyl]cyanuric acid, bisphenol A and -3-ethyl 3-Chloromethyloxetane (abbreviated as OXC) etherate (BisAOX), bisphenol F and OXC etherate (BisFOX), novolak and OXC etherate (PNOX), cresol varnish OXC etherate (CNOX), oxetane sesquioxanes (OX-SQ), 3-ethyl-3-hydroxymethyl oxetane fluorenone alkoxide (OX-SC) ( In the above brackets, the name of the trade name or development product, East Asia Synthetic (stock) system, ETARNACOLL OXBP (Ube Industries Co., Ltd.) , 3,3'-(1,3-(2-methylene)propane bis(oxymethylene)) bis-(3-ethyloxetane), 1,2-double [ (3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetanylmethoxy)methyl Propane, ethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, dicyclopentenyl bis(3-ethyl-3-oxetanylmethyl)ether , triethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, tetraethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, three Hydroxymethylpropane tris(3-ethyl-3-oxetanylmethyl)ether, 1,4-bis(3-ethyl-3-oxetanylmethoxy)butane, 1 ,6-bis(3-ethyl-3-oxetanylmethoxy)hexane, pentaerythritol tris(3-ethyl-3-oxetanylmethyl)ether, pentaerythritol tetra(3) -ethyl-3-oxetanylmethyl)ether, dipentaerythritol hexa(3-ethyl-3-oxetanylmethyl)ether, dipentaerythritol penta(3-ethyl-3- Oxetanemethyl)ether, dipentaerythritol tetrakis(3-ethyl-3-oxetanylmethyl)ether, ditrihydroxymethylpropanetetrakis(3-ethyl-3-oxocycle Butyrylmethyl)ether, and the following formula (A ) to (C) and so on.

Further, examples of the compound having two or more oxetane rings in the molecule include oxetane and novolak resins, cresol varnish resins, poly(hydroxystyrene), and cups. An ethereal compound such as a resin having a hydroxyl group such as a fluorinated resin such as a caliper arene or a silsesquioxane.

Among the above compounds, preferred are alon oxetane OX-SC, OXT-121, OXT-221, PNOX-1009 (above is East Asia Synthetic Co., Ltd.), ETARNACOLL OXBP (Ube Industries, Ltd.) Products), especially OX-SC, OXT-121, OXT-221, PNOX-1009 is particularly good.

Examples of the compound having two or more epoxy groups in the molecule include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and tripropylene glycol diglycidyl. Ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol Glycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N, N', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'- Tetraglycidyl-4,4'-diaminodiphenylmethane or the like.

It can be used together with a compound having two or more oxetane rings in the molecule, and such a compound having two or more epoxy groups in the molecule, and having two or more oxetane rings in the molecule. The compound is preferably used in an amount of 0.01 to 100 parts by weight based on 100 parts by weight of the compound.

[Polyuric acid and ruthenium iodide polymer]

The liquid crystal alignment agent of the present invention is a polyaminic acid synthesized by a polymerization addition reaction of a tetracarboxylic dianhydride and a diamine compound, and/or a ruthenium imidized polymer obtained by imidization of the above polyglycine. The liquid crystal alignment agent is preferably contained in an amount of from 0.01 to 100 parts by weight, based on 100 parts by weight of the total amount of the polymer, of the compound having two or more oxetane rings in the molecule, and is 0.1 to 70 parts by weight. Preferably, it is particularly preferably 1 to 50 parts by weight, or a combination of a compound having 2 or more epoxy groups in the molecule and a compound having 2 or more oxetane rings in the molecule 0.01 to 100 The parts by weight are preferably 0.1 to 70 parts by weight, particularly preferably 1 to 50 parts by weight.

Further, the production method of polylysine and polyimine which can be used in the present invention is as follows.

[tetracarboxylic dianhydride]

The polyimine acid contained in the liquid crystal alignment agent of the present invention and/or the quinone imine compound obtained by the imidization of the polyamic acid may be, for example, a tetracarboxylic dianhydride described below as one of the raw materials. Synthetic preparation.

Examples of the tetracarboxylic dianhydride include butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,2-dimethyl-1,2,3. 4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4 - cyclobutane tetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentane Tetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxyl Cyclopentyl acetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1,3,3a,4,5, 9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene [1,2-c]-furan-1,3-dione, 1,3,3a,4,5 , 9b-hexahydro-5-methyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene [1,2-c]-furan-1,3-dione, 1,3 ,3a,4,5,9b-hexahydro-5-ethyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene[1,2-c]-furan-1,3- Diketone, 1,3,3a,4,5,9b-hexahydro-7-methyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene [1,2-c]- Furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene [1 ,2-c]-furan-1,3-dione, 1,3,3a,4,5,9 B-Hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene [1,2-c]-furan-1,3-dione, 1,3, 3a,4,5,9b-hexahydro-8-ethyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene[1,2-c]-furan-1,3-di Ketone, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene [1,2-c ]-furan-1,3-dione, 5-(2,5-dioxotetrahydrofurfural)-3-methyl-3-hexene-1,2-dicarboxylic dianhydride, bicyclo[2, 2,2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxobicyclo[3.2.1]octane-2,4-dione-6-spiro-3 '-(Tetrahydrofuran-2',5'-dione), 3,5,6-tricarboxy-2-carboxynorbornane-2:3,5:6-dianhydride, bicyclo[3.3.0.] octyl An aliphatic-2 and/or alicyclic tetracarboxylic dianhydride of an alkane-2,4,6,8-tetracarboxylic dianhydride, a compound represented by the following formulas (1) and (2), (wherein R ₁ and R ₃ are each independently a divalent organic group having an aromatic ring, and R ₂ and R ₄ are each independently a hydrogen atom or an alkyl group, and the plural number is in the same R ₂ and R ₄ , and may be the same It can be different.)

And pyromellitic dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 2,3,3',4'-diphenyl ketone tetracarboxylic dianhydride, 2, 2',3,3'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyl fluorene Carboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylate Acid dianhydride, 3,3',4,4'-dimethyldiphenylnonane tetracarboxylic dianhydride, 3,3',4,4'-tetraphenylnonane tetracarboxylic dianhydride, 1,2 , 3,4-furan tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide, 4,4'-bis(3,4-dicarboxyphenoxy Diphenyl hydrazine, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene di Dihydride, bis(phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, double (triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-double (bias Phthalic anhydride), propylene glycol-bis(tert-phthalic anhydride), 1,4-butanediol-bis(tert-phthalic anhydride), 1,6- Alkanediol-bis(terphenylphthalic anhydride), 1,8-octanediol-bis(tert-phthalic anhydride), 2,2-bis(4-hydroxyphenyl)propane-(tert-phthalic anhydride), And an aromatic tetracarboxylic dianhydride represented by the following formulas (3) to (5).

These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

Among the above tetracarboxylic dianhydrides, preferred are: 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1, based on the consideration of exhibiting good liquid crystal alignment properties. , 2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 5-(2,5-dioxotetrahydrofurfural)-3-methyl-3-hexene-1,2-dicarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furan)-naphthalene[1,2-c]furan-1,3-dione 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furan)-naphthalene[1,2-c]furan- 1,3-diketone, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene [ 1,2-c]-furan-1,3-dione, bicyclo[2,2,2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxobicyclo [3.2.1] Octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 3,5,6-tricarboxy-2-carboxynorbornane -2:3,5:6-dianhydride, bicyclo[3.3.0.]octane-2,4,6,8-tetracarboxylic dianhydride, and the compound represented by the above formula (1) are respectively The compound represented by the formula (6) to (8) and the compound represented by the above formula (2) are represented by the following formula ( 9) a compound, pyromellitic dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 2,3,3',4'-diphenyl ketone tetracarboxylic acid Dianhydride, 2,2',3,3'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4' Biphenyltetracarboxylic dianhydride and 1,4,5,8-naphthalenetetracarboxylic dianhydride. Particularly preferred are: 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2 , 4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro- 2,5-dioxo-3-furan)-naphthalene [1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl- 5-(tetrahydro-2,5-dioxo-3-furan)-naphthalene[1,2-c]furan-1,3-dione, 3-oxobicyclo[3.2.1]octane-2 , 4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 3,5,6-tricarboxy-2-carboxynorbornane-2:3,5:6- Dihydride, bicyclo[3.3.0.]octane-2,4,6,8-tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, and the following formula (6) a compound, pyromellitic dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenylfluorene tetracarboxylic dianhydride.

[diamine compound]

When the liquid crystal alignment agent of the present invention is used in the TN mode, the STN mode, the OCB mode, or the VA mode, the synthesis of the polyamic acid and/or the ruthenium iodide polymer contained in the liquid crystal alignment agent of the present invention is used. The diamine compound preferably exhibits a component at a pretilt angle represented by the following formula (10) or the following formula (11). (wherein R ₅ and R ₆ are each independently a hydrogen atom or a methyl group, and R ₇ is a linear or branched alkyl group having 1 to 20 carbon atoms. Further, R ₈ and R ₉ are each independently The same divalent organic group as R ₁₀ below) (wherein a is 0 or 1, and R ₁₀ is selected from the group consisting of an ether bond (-O-), a carbonyl group (-CO-), a carbonyloxy group (-COO-), an oxycarbonyl group (-OCO-), a guanamine bond. (-NHCO-, -CONH-), a thioether bond (-S-), a divalent organic group in a methylene group, and R ₁₁ is a divalent organic group different from R _10. R ₁₂ is a group having a steroid skeleton a radical having a fluorine atom or a linear alkyl group having 1 to 22 carbon atoms)

These diamines having a pretilt angle-presenting component may be used alone or in combination of two or more.

Specific examples of the diamine represented by the above formula (10) include compounds represented by the following formulas (12) and (13), respectively.

Specific examples of the diamine represented by the above formula (11) include compounds represented by the following formulas (14) to (18).

When the liquid crystal alignment agent of the present invention is used in the TN mode, the STN mode, or the OCB mode, it can be stably exhibited by using a diamine which exhibits a composition at a pretilt angle represented by the above formulas (12) to (18). The pretilt angle of the liquid crystal of ~30∘. In this case, the proportion of the diamine having the pretilt angle of the component is preferably 0.5 to 30 mol%, more preferably 0.7 to 20 mol%, especially 1 to 15 mol, based on the total diamine. The ear % is particularly good.

In the case where the liquid crystal alignment agent of the present invention is used in the VA mode, based on the consideration of exhibiting excellent vertical alignment of the liquid crystal, the above-mentioned diamine having a pretilt angle presenting components is used in the formulas (14) and (15), respectively. The compound represented is particularly preferred. The ratio of these diamines is preferably from 8 to 60 mol% for all diamines, more preferably from 9 to 50 mol%, especially 10 to 25 mol%.

Further, in the case where the liquid crystal alignment agent of the present invention is used in the IPS method or the FFS method, a diamine having the above-described pretilt angle presenting component is used, but usually, a diamine having the above-described pretilt angle presenting component can be used only. The external compound is a synthetic polymer.

The polymer used in the liquid crystal alignment agent of the present invention may be a diamine other than the diamine compound having the above pretilt angle-presenting component, and a diamine such as p-phenylenediamine or m-benzene may be used. Diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodi Phenylhydrazine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzoaniline, 4,4'-diaminodiphenyl ether, 1,5 -diaminonaphthalene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 5-amino-1-(4'-aminophenyl)-1,3,3-three Methyl indane, 6-amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 3,4'-diaminodiphenyl ether, 3,3' -diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 4,4'-diaminodiphenyl ketone, 2,2-bis[4-(4-aminophenoxyl) Phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]anthracene, 2, 2-bis[4-(4-aminophenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy) Benzene, 1,3-bis(3-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)-10-hydroquinone , 2,7-diaminopurine, 9,9-bis(4-aminophenyl)anthracene, 4,4'-methylene-bis(2-chloroaniline), 2,2',5,5 '-Tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'- Dimethoxy-4,4'-diaminobiphenyl, 1,4,4'-(p-phenylpropane)diphenylamine, 4,4'-(m-phenylpropane)diphenylamine, 2,2' - bis[4-(4-amino-2-trifluoromethylphenoxy)benzene]hexafluoropropane, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl 4,4'-Diamino-2,2'-dimethylbiphenyl, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl An aromatic diamine such as 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane or 4,4'-bis(4-aminophenoxy)biphenyl; ,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyridine, 5,6-diamino 2,3-dicyanopyridine Pyrazine, 5,6-diamino 2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-three , 1,4-bis(3-aminopropyl)piperazine, 2,4-diamino-6-isopropoxy-1,3,5-three 2,4-diamino-6-methoxy-1,3,5-three 2,4-diamino-6-phenyl-1,3,5-three 2,4-diamino-6-methoxy-s-three 2,4-diamino-1,3,5-three 4,6-Diamino-2-vinyl-s-three , 2,4-diamino-5-phenylthiazole, 2,6-diaminophenyl phenyl, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino -1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diamine a piperidazine, a 3,6-diamino acridine, a bis(4-aminophenyl)phenylamine, and a compound represented by the following formulas (19) and (20), respectively, having two in the molecule a first amine group and a diamine of a nitrogen atom other than the amine group; (wherein R ₁₃ represents a group selected from the group consisting of pyridine, pyrimidine, and tri Among the piperidines and piperazines, a monovalent organic group having a ring structure containing a nitrogen atom, and X represents a divalent organic group. ) (wherein R ₁₄ represents a group selected from the group consisting of pyridine, pyrimidine, and tri A divalent organic group having a ring structure containing a nitrogen atom among piperidine and piperazine. )

1,3-bis(aminomethyl)cyclohexane, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octadecylene Diamine, 9-methylenediamine, 4,4-diaminopentamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentenediamine, hexahydrogen -4,7-Methanol is an aliphatic group of dimethylenediamine, tricyclo[6.2.1.0 ^2.7 ]-undecylenediamine, 4,4'-methylenebis(cyclohexylamine), etc. And an alicyclic diamine; a diamine organooxane represented by the following formula (21); (Wherein, R ₁₅ represents a hydrocarbon group having 1 to 12 carbon atoms, the presence of a plurality of R _15, may be the same or different from each other, p is an integer of 1 to 3, q is an integer of from 1 to 20.) Containing these pretilt The diamine compound other than the diamine compound of the component may be used alone or in combination of two or more.

Among these, preferred are: p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2 , 7-diaminopurine, 4,4'-diaminodiphenyl ether, 9,9-bis(4-aminophenyl)anthracene, 2,2-bis[4-(4-aminophenoxyl) Phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 1, 4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-2,2'-bis(trifluoro Methyl)biphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diamine a compound represented by the following formula (22) and a compound represented by the above formula (20) in the compound represented by the above formula (19), wherein the pyrimidine, the 3,6-diamino acridine, the compound represented by the above formula (19) a compound represented by the above formula (21), 1,3-bis(aminomethyl)cyclohexane, 1,4-cyclohexanediamine, 4,4'-methylenebis(cyclohexylamine) Among the compounds shown, 3,3'-(tetramethyldicyclohexane-1,3-dioxene) bis(propylamine) represented by the following formula (24).

Particularly preferred are p-phenylenediamine, 4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4' -diaminodiphenyl ether, 2,7-diamino guanidine, 3,3'-(tetramethyldicyclohexane-1,3-dioxin) bis(propylamine), 2,2-bis[4 -(4-Aminophenoxy)phenyl]propane, 1,3-bis(aminomethyl)cyclohexane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4 '-Diamino-2,2'-bis(trifluoromethyl)biphenyl.

<Synthesis of polyaminic acid>

The ratio of use of the tetracarboxylic dianhydride to the diamine compound used in the synthesis reaction of the polyaminic acid of the present invention is preferably 1 equivalent of the amine group contained in the diamine compound, and the tetracarboxylic acid The anhydride group of the anhydride is in a ratio of 0.2 to 2 equivalents, more preferably in a ratio of 0.3 to 1.2 equivalents.

The synthesis reaction of polylysine is preferably carried out in an organic solvent at a temperature of from -20 to 150 ° C, more preferably from 0 to 100 ° C. Here, the organic solvent is not particularly limited as long as it is a polylysine which can be dissolved and synthesized, and examples thereof include N-methyl-2-pyrrolidone and N,N-dimethylacetamide. , aprotic polar solvents such as N,N-dimethylformamide, dimethyl hydrazine, γ-butyrolactone, tetramethyl urea, hexamethylphosphoric acid trisamine; m-cresol, xylenol, A phenol solvent such as phenol or halogenated phenol. These solvents may be used alone or in combination of two or more. In addition, the amount (a) of the organic solvent used is (b) in the total amount of the tetracarboxylic dianhydride and the diamine compound, and is 0.1 to 30% by weight based on the total amount (a+b) of the reaction liquid. The amount is better.

Further, in the above solvent, an alcohol, a ketone, an ester, an ether or a halogenated hydrocarbon of a poor solvent of polyproline may be used in combination in a range in which the produced polyamine acid is not precipitated. Specific examples of the poor solvent include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, diacetone alcohol, and ethylene. Alcohol monomethyl ether, ethyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate Ester, propylene carbonate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol Ether, ethylene glycol ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, and the like. These poor solvents may be used alone or in combination of two or more.

As shown, a reaction solution obtained by dissolving polylysine can be obtained. Then, the reaction solution is poured into a large amount of a poor solvent to obtain a precipitate, and then the precipitate is dried under reduced pressure to obtain a polyamine. Further, the polyamic acid is dissolved again in an organic solvent, and then precipitated in a poor solvent, and the polyamine acid can be purified in one or several steps.

<醯iminated polymer>

The quinone imidized polymer used in the liquid crystal alignment agent of the present invention can be synthesized by subjecting the above polyamic acid to dehydration ring closure. Here, the ruthenium iodide polymer contains a partially ruthenium imidized polymer and a 100% ruthenium iodide polymer which are one part of the above polylysine, and the following is a general term for this. It is labeled as "醯iminated polymer".

In the ruthenium iodide polymer used in the liquid crystal alignment agent of the present invention, the preferred oxime imidization ratio is 10 to 100%, preferably 20 to 95%, and particularly preferably 45 to 90%. Here, the "yttrium imidization ratio" is a ratio of the number of repeating units of the ruthenium ring formed with respect to the total number of repeating units in the polymer. Example (%) indicates. At this time, one part of the ruthenium ring may also be an isoindole ring.

As a method for synthesizing the ruthenium ring, (I) a method of synthesizing the polypyridic acid by heating and dehydrating it, and (II) dissolving the polylysine in an organic solvent, if necessary. A method in which a dehydrating agent and a dehydration ring-closing catalyst are added to the solution and heated to thereby dehydrate and ring-close is synthesized. The above reaction conditions are appropriately controlled to obtain a desired polymer having a ruthenium iodide ratio.

The reaction temperature in the above method (I) for heating polylysine is preferably 50 to 300 ° C, more preferably 100 to 250 ° C. If the reaction temperature is less than 50 ° C, the dehydration ring-closure reaction does not proceed sufficiently, and if the reaction temperature exceeds 300 ° C, the molecular weight of the obtained ruthenium-imided polymer is lowered.

On the other hand, in the above method (II) in which a dehydrating agent and a dehydration ring-closing catalyst are added to a solution of poly-proline, as the dehydrating agent, an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used. The amount of the dehydrating agent to be used is preferably 0.01 to 20 moles per 1 mole of the repeating unit of the polyamic acid. Further, as the dehydration ring-closing catalyst, a tertiary amine such as pyridine, collidine, lutidine or triethylamine can be used. However, the dehydrating agent and the dehydration ring-closing catalyst are not limited to these examples. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per mol of the dehydrating agent used. Further, examples of the catalyst for the dehydration ring closure reaction are the same as those exemplified for the synthesis of polylysine. Further, the reaction temperature of the dehydration ring closure reaction is preferably from 0 to 180 ° C, more preferably from 60 to 150 ° C. Further, by purifying the reaction solution thus obtained with poly-proline The same operation of the method can be used to refine the ruthenium iodide polymer.

<End modified polymer>

The polyamic acid and the quinone imidized polymer constituting the liquid crystal alignment agent of the present invention may also be a terminal modified polymer having a molecular weight adjusted. By using this terminal-modified polymer, the coating properties and the like of the liquid crystal alignment agent can be improved without impairing the effects of the present invention. These terminal modification types can be synthesized by adding an acid anhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing polyamine. Here, examples of the acid anhydride include a dicarboxylic acid anhydride, and examples thereof include maleic anhydride, phthalic anhydride, anhydrous itaconic acid, n-decyl salicylic anhydride, and n-dodecyl salicylic anhydride. N-tetradecyl salicylic anhydride, n-hexadecyl salicylic anhydride, and the like. Further, examples of the monoamine compound include aniline, cyclohexylamine, p-ethylaniline, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-decylamine, n-decylamine, and Undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecaneamine, n-octadecylamine, n-dodecylamine, and the like. Further, examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

<solution viscosity>

The polymer used in the alignment agent of the present invention has a viscosity of 20 to 800 mPa when used as a 10% by weight solution. s is better, with a viscosity of 30~500mPa. s is better.

Further, the solution viscosity (mPa.s) of the polymer is a solution diluted to a solid concentration of 10% by weight with a predetermined solvent, and the E-type rotational viscosity is used. Measured at 25 ° C.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention is a polyaminic acid synthesized by polycondensation reaction of a tetracarboxylic dianhydride with a diamine, and/or a ruthenium imidized polymer obtained by imidization of the above polyglycine. The oxetane compound or its epoxy compound is dissolved in a usual organic solvent.

Examples of the polymer used in the invention include (A) one or more kinds of polylysine alone, (B) one or more kinds of ruthenium-imidized polymers, and (C) poly-proline and sulfonate. A mixture of aminated polymers. Among these, based on the achievement of characteristics such as good voltage holding ratio and baking resistance (residual DC), (B) one or more kinds of ruthenium iodide polymers and (C) polyproline are used. Mixtures with hydrazine imidized polymers are preferred.

Further, in the case of using (C) a mixture of a polyamic acid and a ruthenium iodide polymer, the ruthenium imidization ratio in the ruthenium iodide polymer is preferably in the range of 45 to 100%, and is 55 to 100. % is better. In this case, if a mixture selected from 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride is used, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-( Tetrahydro-2,5-dioxo-3-furan)naphthalene [1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8- Methyl-5-(tetrahydro-2,5-dioxo-3-furan)naphthalene[1,2-c]-furan-1,3-dione, 3-oxobicyclo[3.2.1] octane One or more kinds of tetracarboxylic dianhydrides in a group consisting of alkane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione) and pyromellitic dianhydride And selected from p-phenylenediamine, 4,4'-diaminobiphenyl Alkane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2,7-diamino fluorene, 3,3'-(four Methyl dicyclohexane-1,3-dioxyl) bis(propylamine), 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis(amino group) a group of cyclohexane, 2,2-bis(4-aminophenyl)hexafluoropropane and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl The polyglycolic acid and the ruthenium iodide polymer obtained by reacting one or more kinds of diamines can have high voltage holding ratio, baking resistance (residual DC), and alignment coating properties. The liquid crystal alignment film is preferred. In this case, the weight ratio of the polyamic acid to the ruthenium iodide polymer is preferably a polyglycine: ruthenium iodide polymer = 10:90 to 90:10, more preferably poly Proline: yttrium imidized polymer = 30:70~85:15 range, especially for polyglycine: hydrazide polymer = 50:50~80:20.

The temperature at which the liquid crystal alignment agent of the present invention is prepared is preferably 0 to 200 ° C, more preferably 20 to 60 ° C.

The organic solvent constituting the liquid crystal alignment agent of the present invention may be the same as the solvent exemplified for the synthesis reaction for polyglycine. However, it is only necessary to select the solvent in consideration of the solubility of the raw material and the reactant in the synthesis reaction, and in the liquid crystal alignment agent, it is necessary to further consider the storage stability and the printability and coating property of the next step. It may also be a solvent other than the organic solvent in the synthesis reaction of polylysine or the like. From the viewpoint of printability, a solvent having a boiling point of 160 ° C or more is preferable, and examples thereof include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl hydrazine, and γ-butyl. Lactone, tetramethyl urea, hexamethylphosphoric acid trisamine, m-cresol, xylenol, Phenol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, diacetone alcohol, butyl lactate, butyl acetate, ethyl ethoxy propionate, propylene carbonate, oxalic acid Diethyl ester, diethyl malonate, ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol Monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 1,4-bicyclobutane, o-dichlorobenzene, etc.; preferably: N-methyl-2-pyrrolidone , γ-butyrolactone, diacetone alcohol, ethylene glycol monobutyl ether (butyl cellosolve), propylene carbonate, diethylene glycol diethyl ether. A particularly preferable solvent composition is a composition obtained by combining the above solvents, and is a composition in which the polymer in the alignment agent does not precipitate and the surface tension of the alignment agent is in the range of 25 to 40 mN/m.

The solid content concentration in the liquid crystal alignment agent of the present invention can be selected in consideration of viscosity, volatility and the like. It is preferably in the range of 1 to 10% by weight. That is, the liquid crystal alignment agent of the present invention is applied to the surface of the substrate to form a coating film as a liquid crystal alignment film. When the solid concentration is less than 1% by weight, the film thickness of the coating film is too thin, which makes it difficult to obtain Good liquid crystal alignment film. When the solid content concentration exceeds 10% by weight, the thickness of the coating film is too thick, so that it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent is increased, so that the coating property is liable to be deteriorated.

Further, the particularly preferable solid concentration range varies depending on the method used to apply the liquid crystal alignment agent to the substrate. For example, in the case of the spin coating method, it is particularly preferably 1.5 to 4.5% by weight. In the case of the printing method, the solid content concentration is set to be in the range of 3 to 9 wt%, and the solution viscosity is set to 12 to 50 mPa. The range of s is particularly good. In the case of the inkjet method, the solid concentration is set to 1 ~5 wt% range, and the solution viscosity is set to 3 ~ 15mPa. The range of s is particularly good.

Further, the temperature at which the liquid crystal alignment agent of the present invention is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

The liquid crystal alignment agent of the present invention may contain other additives as needed. As an additive, a functional decane-containing compound can be mentioned from the viewpoint of improving the bonding property to the surface of the substrate and increasing the voltage holding ratio. Examples of such a functional decane-containing compound include 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2- Aminopropyltriethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyl Dimethoxyoxane, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxyxy-3-aminopropyltrimethoxydecane, N-B Oxycarboxy-3-aminopropyltriethoxydecane, N-triethoxydecylpropyltriamine, N-trimethoxydecylpropyltriamine, 10-trimethoxydecane -1,4,7-triazadecane, 10-triethoxydecane-1,4,7-triazadecane, 9-trimethoxydecane-3,6-diazahamidoacetate , 9-triethoxydecane-3,6-diazahamidoacetate, N-benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxy Baseline, N-phenyl-3-aminopropyltrimethoxydecane, N-phenyl-3-aminopropyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, N-bis(ethyleneoxy) , 3-aminopropyltrimethoxydecane, N-bis(ethyleneoxy)-3-aminopropyltriethoxydecane, and the like.

The proportion of such functional decane-containing compounds relative to polyamine The total amount of the acid and/or quinone imidized polymer is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, more preferably 100 parts by weight or less.

<Liquid crystal display element>

The liquid crystal display element of the present invention can be produced, for example, by a method described later.

(1) Coating on one surface of a substrate provided with a patterned transparent conductive film by, for example, a roll coating method, a spin coating method, a printing method, an inkjet method, or the like, and then coating the coated surface Heating forms a coating film. Here, as the substrate, for example, glass such as float glass or soda glass; polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, or fat can be used. A transparent substrate made of a plastic such as a cyclic polyolefin is used as a transparent conductive film provided on one side of the substrate. The NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ) can be used. An ITO film made of tin (In ₂ O ₃ -SnO ₂ ). The patterning of such transparent conductive films can be by photolithography or by using a mask. The reflective electrode may be a metal such as Al or Ag or an alloy containing such a metal. However, it is not limited thereto as long as it has sufficient reflectance. When the liquid crystal alignment agent is applied, in order to further improve the adhesion between the substrate surface and the transparent conductive film or the reflective electrode and the liquid crystal alignment film, the functional decane compound and the functional titanium may be coated on the surface of the substrate. Compounds, etc. After the liquid crystal alignment agent is applied, prebake can usually be performed for the purpose of preventing the vertical flow of the applied alignment agent. The preheating temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. Then, the solvent is completely removed, and a postbake step for the purpose of heat-imidizing the polyglycine unit to a polyimine unit is carried out. The postbake temperature is preferably 80 to 300 ° C, and more preferably 120 to 250 ° C. In this manner, the liquid crystal alignment agent of the present invention containing a poly-proline unit can be formed into a liquid crystal alignment film by removing the organic solvent after coating, and then subjected to dehydration ring closure by heating, thereby making further imidization. Liquid crystal alignment film. The film thickness of the liquid crystal alignment film to be formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(2) The formed coating film surface may be subjected to a rubbing treatment in a characteristic direction by a roll wound with a cloth made of, for example, a fiber such as nylon, crepe or cotton, as needed. Thereby, a liquid crystal alignment film which imparts an alignment energy to liquid crystal molecules can be formed. Further, in addition to the method of rubbing treatment, a method of irradiating the surface of the coating film with ultraviolet rays to control the alignment energy may be used. In addition, in order to remove the fine powder (foreign matter) generated during the rubbing treatment, the surface of the coating film is cleaned, and it is preferable to wash the formed liquid crystal alignment film with isopropyl alcohol and/or pure water. Further, the liquid crystal alignment film which is formed by the liquid crystal alignment agent of the present invention is changed by irradiating with ultraviolet rays to change the pretilt as shown in Japanese Laid-Open Patent Publication No. Hei 6-222366 or No. Hei 6-281937. The treatment of the corners; or the partial formation of the photoresist film on the rubbed liquid crystal alignment film as shown in Japanese Laid-Open Patent Publication No. Hei 5-105044, after the rubbing treatment is performed in a direction different from the previous rubbing treatment, the light is irradiated The barrier film is removed to change the alignment energy of the liquid crystal alignment film, whereby the viewing angle characteristics of the liquid crystal display element can be improved.

(3) Two sheets of the substrate on which the liquid crystal alignment film is formed are formed by the above method so that the rubbing directions of the respective liquid crystal alignment films become perpendicular or reverse In a parallel manner, two substrates are arranged to face each other via a cell gap, and the peripheral portions of the two substrates are bonded by a sealant, and liquid crystal is filled in the cell gap separated by the surface of the substrate and the sealant. The injection hole is sealed to constitute a liquid crystal cell. Then, a polarizing plate is disposed on the outer surface of the liquid crystal cell (that is, the outer side of each of the substrates constituting the liquid crystal cell), whereby a liquid crystal display element is obtained.

Here, as the sealant, for example, an alumina ball-containing epoxy resin or the like which is a hardener and a spacer can be used.

Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, a nematic liquid crystal is preferable, and for example, a Schiff base liquid crystal, an oxidized azo liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal, or the like can be used. Biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubic liquid crystal, or the like. Further, a cholesteric liquid crystal such as chlorinated cholesterol, cholesteryl citrate or cholesteryl carbonate may be added to the liquid crystal or a pair sold under the trade name "C-15" "CB-15" (manufactured by Merck). Use as a palmizing agent. Further, a ferroelectric liquid crystal such as p-nonylbenzene-p-amino-2-methylbutyl cinnamyl ester can also be used.

In addition, as a polarizing plate which is bonded to the surface of the liquid crystal cell, a polarizing film called a H film which is formed by absorbing iodine while extending polyvinyl alcohol and sandwiching it with a cellulose acetate protective film is used. , or the polarizing plate of the H film itself.

As described above, the liquid crystal alignment film formed of the liquid crystal alignment agent containing the compound having an oxetane ring of the present invention is excellent in alignment property and A liquid crystal alignment film exhibiting high voltage holding ratio and excellent reliability of voltage holding ratio.

The liquid crystal display device of the present invention can be effectively used in various devices, and can be preferably applied to display devices such as desktop computers, watches, clocks, mobile phones, counting display panels, word processors, personal computers, and liquid crystal televisions. .

[Examples]

In the following, the invention will be more specifically described by the examples, but the invention is not limited by the examples. Moreover, the evaluation items and evaluation methods of the liquid crystal alignment agent prepared in the following examples and comparative examples are as follows:

(vertical alignment of liquid crystal molecules)

The vertical alignment of the vertical alignment type liquid crystal display element was observed when the voltage was OFF and the liquid crystal display element was observed under an alternating current of 12 V (peak-peak), and was judged as "good" in the case of no abnormality.

(voltage holding ratio)

When a liquid crystal display element was applied with a voltage of 5 V at 60 ° C for 60 μsec and applied for a period of 1670 msec, after 1670 m after the voltage application of 5 V was released, the VHR of Dongyang Technology Co., Ltd. was used. 1 Determine its holding voltage. At this time, the liquid crystal system was a negative type MLC-2038 (manufactured by Merck Co., Ltd.).

(High temperature test of liquid crystal display element)

The heat resistance of the vertical alignment type liquid crystal display element is such that the element is left at a high temperature (100 ° C) and a humidity of 50% RH for 10 days, and it is confirmed whether or not an abnormal region is present in the liquid crystal cell when the voltage is turned ON or OFF.

(Reliability test of liquid crystal display element)

The reliability of the liquid crystal alignment agent is a rectangular wave of 30 Hz and 3.0 V which is formed by superimposing a direct current 6.0 V and an alternating current 6.0 V (peak-peak) on a vertical alignment type liquid crystal display element, and after applying it at ambient temperature for 150 hours, The voltage was turned OFF, and after the afterimage disappeared, it was visually confirmed whether or not it was uniformly aligned vertically without mottle. The voltage holding ratios before and after the high temperature test were compared.

(Synthesis Example 1) Synthesis of Polyimine Polymer

20 g (0.091 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 7.9 g (0.073 mol) of p-phenylenediamine as a diamine compound and the above formula ( 15) The indicated diamine compound 9.1 g (0.018 mol) was dissolved in 150 g of N-methyl-2-pyrrolidone, and reacted at 60 ° C for 4 hours. A small amount of the obtained polyaminic acid solution was taken out, and a solution of NMP in a solid concentration of 10% by weight was added, and the viscosity was determined to be 60 mPa. s. To the obtained polyglycine, 350 g of N-methyl-2-pyrrolidone was added and dissolved, and 14 g of pyridine and 19 g of acetic anhydride were further added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the reaction system is replaced with a new γ-butyrolactone solvent (by this operation) The pyridine and acetic anhydride used in the amination reaction were removed to the reaction system) to obtain a solid concentration of 15% by weight, and a solution viscosity of 58 mPa at a solid concentration of 10% by weight (γ-butyrolactone solution). A solution of about 53, 醯 imidization of about 53% of a ruthenium imidized polymer (as a "polymer P-1") solution was about 240 g.

(Synthesis Example 2) Synthesis of Polyimine Polymer

22 g (0.10 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as a tetracarboxylic dianhydride, and 9.9 g (0.091 mol) of p-phenylenediamine as a diamine compound and the above formula ( 15) The diamine compound (5.4 g (0.011 mol)) was dissolved in 150 g of N-methyl-2-pyrrolidone, and reacted at 60 ° C for 4 hours. A small amount of the obtained polyamic acid solution was taken out, and NMP was added to a solution having a solid concentration of 10% by weight, and the viscosity was determined to be 48 mPa. s. To the obtained polyglycolic acid, 350 g of N-methyl-2-pyrrolidone was added and dissolved, and 16 g of pyridine and 20 g of acetic anhydride were further added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the reaction system is replaced with a new γ-butyrolactone (by the operation, the pyridine and acetic anhydride used in the oxime imidization reaction are removed to the reaction system). The solid solution concentration is 15% by weight, and the solution viscosity at the solid concentration of 10% by weight (γ-butyrolactone solution) is 45 mPa. The solution of s, yttrium imidization polymer (about as "polymer P-2") having a yield of about 51% was about 230 g.

(Synthesis Example 3) Synthesis of Polyimine Polymer

20 g (0.09 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 8.0 g (0.073 mol) of p-phenylenediamine as a diamine compound and the above formula ( 14) The diamine compound (9.2 g (0.018 mol)) was dissolved in 150 g of N-methyl-2-pyrrolidone, and reacted at 60 ° C for 4 hours. A small amount of the obtained polyamic acid solution was taken out, and a solution of NMP was added to a solid concentration of 10% by weight, and the viscosity was determined to be 65 mPa. s. To the obtained polyglycine, 350 g of N-methyl-2-pyrrolidone was added and dissolved, and 14 g of pyridine and 18 g of acetic anhydride were further added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the reaction system is replaced with a new γ-butyrolactone (by the operation, the pyridine and acetic anhydride used in the oxime imidization reaction are removed to the reaction system). The solid solution concentration is 16% by weight, and the solution viscosity (γ-butyrolactone solution) at a solid concentration of 10% by weight is 63 mPa. A solution of about 56, 醯 imidization of about 56% of a ruthenium-imiding polymer (as a "polymer P-3") solution was about 240 g.

(Example 1)

The polymer P-1 obtained in Synthesis Example 1 and a specific oxetane compound a (20 parts by weight based on 100 parts by weight of the polymer) described later were dissolved in N-methyl-2-pyrrolidone/butyl cellulase. The mixed solution (weight ratio 50/50) was used as a solution having a solid content concentration of 3% by weight. This solution was filtered through a filter having a pore size of 1 μm to prepare a film-forming composition of the present invention.

Then, on one side of the glass substrate having a thickness of 1 mm The film-forming composition was applied onto a transparent conductive film made of an ITO film by a spin coater, and dried at 200 ° C for 60 minutes to form a film having a dry film thickness of 0.06 μm.

Then, an epoxy resin bonding agent in which alumina balls having a diameter of 5.5 μm are mixed and applied to each of the outer edges of the liquid crystal alignment film on which the liquid crystal alignment film coating substrate is provided on the pair of transparent electrodes/transparent electrode substrates is applied. The liquid crystal alignment films are laminated and pressed in opposite directions to harden the bonding agent. Then, a negative liquid crystal (MLC-2038, manufactured by Merck Co., Ltd.) was filled between the substrates through the liquid crystal inlet, and the liquid crystal injection port was sealed with an acrylic light curing agent, and a polarizing plate was bonded to both surfaces of the substrate to form a liquid crystal display element.

The vertical alignment type liquid crystal display element produced as described above has a good vertical alignment property, and the image sticking evaluation by the brightness also shows that the difference in luminance is small, and it is regarded as "good image sticking". The voltage holding ratio was 98.4%, and since the voltage holding ratio in the case where the oxetane compound a was not added was 96.4%, it was further improved by adding an additive. Moreover, in the case of being placed at a high temperature, no uneven distribution due to temperature was observed, and good results were obtained, and the voltage holding ratio was compared with that before and after the constant temperature test, compared with the case where no oxetane compound was added. The decrease was about 5%, and the addition of oxetane was reduced by about 1%. Therefore, it was confirmed that the liquid crystal display element produced by using the present embodiment has an excellent voltage holding ratio, and the reliability at a high temperature is also excellent in the voltage holding ratio.

(Examples 2 to 12)

The polymers P-1 to P-3 obtained in Synthesis Examples 1 to 3 were respectively mixed with oxygen a cyclobutane compound or an oxetane compound and an epoxy compound are dissolved in a mixed solution of N-methyl-2-pyrrolidone/butyl-cellulose (weight ratio 50/50) to obtain a solid concentration of 3 % by weight solution. This solution was filtered through a filter having a pore size of 1 μm to prepare a film-forming composition of the present invention. The compositions are shown in Table 1 below. As the oxetane, the oxetane compound a (20 parts by weight for 100 parts by weight of the polymer) was used in Examples 1, 5 and 9, respectively, and oxygen was used in Examples 2, 6, and 10, respectively. a heterocyclic butane compound b (20 parts by weight per 100 parts by weight of the polymer), and an oxetane compound d in each of Examples 3, 7, and 11 (20 parts by weight per 100 parts by weight of the polymer) In each of Examples 4, 8, and 12, an oxetane compound c (15 parts by weight per 100 parts by weight of the polymer) and an epoxy compound (5 parts by weight per 100 parts by weight of the polymer) were respectively used. In the same manner as in Example 1, a liquid crystal cell was produced and various evaluations were carried out. The results are shown in Table 2 below. Further, each of the above oxetane compounds is specified as described later.

(Comparative examples 1 to 6)

Only the polymers P-1 to P-3 obtained in Synthesis Examples 1 to 3 were used, or these polymers were dissolved with only the epoxy compound (20 parts by weight per 100 parts by weight of the polymer), respectively. A liquid crystal cell was produced in the same manner as in Example 1, and various evaluations and tests were carried out. The results are shown in Table 2 below. Further, the composition is shown in Table 1.

The above oxetane compounds are all epoxy compounds N, N, N', N'-tetraglycidyl-4,4'-diaminodiphenylmethane.

As is clear from Table 2, the liquid crystal alignment film obtained from the liquid crystal alignment agents obtained in Examples 1 to 12 exhibited a high voltage holding ratio as compared with the comparative example, and was excellent in reliability of the voltage holding ratio. The above characteristics of the liquid crystal alignment agent of the present invention can be adjusted by the selection and addition amount of the added oxetane compound.

As described above, according to the present invention, it is possible to provide a liquid crystal display element having a high-voltage retention ratio and excellent reliability of a voltage holding ratio, and a liquid crystal alignment film, and having a magnified image.

Claims (4)

A liquid crystal alignment agent comprising: (A) a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine compound, and/or a ruthenium iodide polymer thereof, and (B-1) a compound having two or more oxetane rings in the molecule, or (B-2) a compound having two or more epoxy groups in the molecule and having two or more oxetane in the molecule A combination of compounds of an alkane ring, wherein the compound having two or more oxetane rings in the molecule is a group selected from the group consisting of compounds represented by the following formulas (A), (B) and (C); At least one of them; (wherein, Ra is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Rb is an organic group having 1 to 20 carbon atoms, and 1 is 0 or 1) (wherein n is the number of functional groups bonded to Rc, an integer of 3 or more, Rc is an organic group of n valence, and Ra is defined as the above formula (A)) (wherein Rd is a divalent organic group, and m is an integer of 1 to 10). The liquid crystal alignment agent of claim 1, wherein at least one of the tetracarboxylic dianhydrides is selected from the group consisting of 2,3,5-tricarboxylic acid cyclopentyl acetic acid dianhydride, 1,2,3,4- Cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5 -(tetrahydro-2,5-dioxo-3-furan)-naphthalene[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro- 8-methyl-5-(tetrahydro-2,5-dioxo-3-furan)-naphthalene[1,2-c]furan-1,3-dione, 1,2,3,4-ring Pentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3-oxabicyclo[3,2,1]octane-2,4-dione-6- Spiro-3'-(tetrahydrofuran-2',5'-dione), 3,5,6-tricarboxy-2-carboxynorbornane 2:3,5:6 dianhydride and bicyclo[3,3, 0] octane-2,4,6,8-tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 3,3' , 4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenylfluorene tetracarboxylic dianhydride, a compound represented by the following formula In the group formed. A liquid crystal alignment agent according to claim 1 or 2, which is used for forming a vertical alignment liquid crystal alignment film. A liquid crystal display element substrate comprising a liquid crystal display element substrate having a liquid crystal alignment film formed by the liquid crystal alignment agent according to any one of claims 1 to 3.