JP2980080B2 - Liquid crystal alignment agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal aligning agent, and more particularly, to a liquid crystal aligning agent having good printability, adhesion, and liquid crystal alignment (especially, display failure is less likely to occur at the periphery of a liquid crystal display screen). About.

[0002]

2. Description of the Related Art Conventionally, a sandwich structure is formed by forming a layer of a nematic liquid crystal having a positive dielectric anisotropy between two substrates having a liquid crystal alignment film formed on the surface thereof through a transparent conductive film. A TN type liquid crystal display element having a TN (Twisted Nematic) type liquid crystal cell in which the major axis of the liquid crystal molecules is continuously twisted by 90 degrees from one substrate to the other substrate is known. I have. Orientation of liquid crystal in a liquid crystal display element such as a TN type liquid crystal display element is usually realized by a liquid crystal alignment film provided with an alignment ability of liquid crystal molecules by rubbing. Here, as a material of a liquid crystal alignment film constituting a liquid crystal display element, resins such as polyimide, polyamide, and polyester are conventionally known. In particular, polyimide is used in many liquid crystal display devices because of its excellent heat resistance, affinity with liquid crystal, mechanical strength, and the like.

[0003]

However, in a liquid crystal display device or the like using a liquid crystal alignment film containing a conventionally known polyamic acid or a polyimide polymer having a structure obtained by dehydrating and cyclizing the same, it can be obtained. In addition, there is a problem that display defects are likely to occur at the peripheral portion of the liquid crystal display element. This is thought to be a phenomenon caused by chemical adsorption or a chemical reaction between the liquid crystal alignment film and a chemical substance such as a sealant for bonding a glass substrate, a sealing agent for sealing a liquid crystal injection port, and is caused by unevenness of the liquid crystal alignment film surface. It is considered that the size of the adsorption surface area greatly affects this phenomenon.
The present invention has been made in view of the above circumstances, and a first object of the present invention is to reliably impart liquid crystal molecule alignment ability by rubbing treatment, and to provide excellent printability, adhesion, An object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal alignment film having liquid crystal alignment. A second object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal alignment film that does not cause display defects at the periphery of a liquid crystal display element.

[0004]

Means for Solving the Problems The liquid crystal aligning agent of the present invention comprises:
[A] at least one polymer selected from polyamic acids and imidized polymers of polyamic acids, [b-
1] The following formula (i):

[0005]

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(In the formula, A ^{1 to} A ¹¹ each independently represent an alkyl group or a hydrogen atom.)

(Hereinafter, also referred to as “compound (i)”). Alternatively, [a] at least one polymer selected from polyamic acids and imidized polymers of polyamic acids, and [b-2] the following formula (ii):

[0008]

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(In the formula, A ^{12 to} A ¹⁴ each independently represent an alkyl group or a hydrogen atom.)

Characterized by containing a compound and / or a polymer having the structure shown below (hereinafter, also referred to as “compound (ii)”). Hereinafter, the present invention will be described in detail.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

<(A-1) Polyamic acid> The polyamic acid constituting the liquid crystal aligning agent of the present invention can be prepared by reacting a tetracarboxylic dianhydride with a diamine compound.

The tetracarboxylic dianhydride used in the polyamic acid synthesis reaction includes, for example, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2- Dimethyl-
1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-
Cyclopentanetetracarboxylic dianhydride, 1,2,2
4,5-cyclohexanetetracarboxylic dianhydride,
3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, , 3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a,
4,5,9b-Hexahydro-5 (tetrahydro-2,
5-dioxo-3-furanyl) -naphtho [1,2-c]
-Furan-1,3-dione, 1,3,3a, 4,5,9
b-Hexahydro-5-methyl-5 (tetrahydro-
2,5-dioxo-3-furanyl) -naphtho [1,2-
c] -furan-1,3-dione, 1,3,3a, 4,
5,9b-Hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,
2-c] -furan-1,3-dione, 1,3,3a,
4,5,9b-Hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3
a, 4,5,9b-Hexahydro-7-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3
3a, 4,5,9b-Hexahydro-8-methyl-5
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] -furan-1,3-dione, 1,
3,3a, 4,5,9b-hexahydro-8-ethyl-
5 (tetrahydro-2,5-dioxo-3-furanyl)
-Naphtho [1,2-c] -furan-1,3-dione,
1,3,3a, 4,5,9b-hexahydro-5,8-
Dimethyl-5 (tetrahydro-2,5-dioxo-3-
Furanyl) -naphtho [1,2-c] -furan-1,3-
Dione, 5- (2,5-dioxotetrahydrofural)
-3-Methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-
Aliphatic and alicyclic tetracarboxylic dianhydrides such as ene-2,3,5,6-tetracarboxylic dianhydride, compounds represented by the following formulas (I) and (II);

[0013]

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(Wherein, R ¹ and R ^{4 each} represent a divalent organic group having an aromatic ring, R ² and R ^{3 each} represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ³ represent , May be the same or different.)

Pyromellitic dianhydride, 3,3 ', 4
4'-benzophenonetetracarboxylic dianhydride, 3,
3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3 , 3 ′, 4,4′-biphenylethertetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride,
3,3 ', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) ) Diphenyl sulfide dianhydride, 4,4 '
-Bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,
3 ', 4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p -Phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (tri Phenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimeritate) Trimellitate), 1,6-hexanediol-bis (anhydrotrimellitate),
1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), represented by the following formulas (1) to (4) And aromatic tetracarboxylic dianhydrides such as These are used alone or in combination of two or more.

[0016]

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Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Anhydride, 1,2,3,4-
Cyclopentanetetracarboxylic dianhydride, 2,3,5
-Tricarboxycyclopentylacetic dianhydride, 5-
(2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5-
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] furan-1,3-dione, 1,
3,3a, 4,5,9b-hexahydro-8-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione;
1,3,3a, 4,5,9b-hexahydro-5,8-
Dimethyl-5- (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-c] furan-1,3-
Dione, bicyclo [2,2,2] -oct-7-ene-
2,3,5,6-tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′- Biphenylsulfonetetracarboxylic dianhydride, 1,4
5,8-Naphthalenetetracarboxylic dianhydride, among the compounds represented by the formula (I), the compounds represented by the following formulas (5) to (7) and the compound represented by the following formula (II): The compound represented by (8) is preferred from the viewpoint that good liquid crystal alignment can be exhibited, and particularly preferred are 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,3-dimethyl −1, 2,
3,4-cyclobutanetetracarboxylic dianhydride, 2,
3,5-tricarboxycyclopentylacetic acid dianhydride,
1,3,3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3 3
a, 4,5,9b-Hexahydro-8-methyl-5-
(Tetrahydro-2,5-dioxo-3-furanyl)-
Examples thereof include naphtho [1,2-c] furan-1,3-dione, pyromellitic dianhydride and a compound represented by the following formula (7).

[0018]

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Examples of the diamine compound used in the synthesis reaction of the polyamic acid include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane,
4,4'-diaminodiphenyl sulfide, 4,4'-
Diaminodiphenyl sulfone, 3,3'-dimethyl-
4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3-dimethyl-
4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4 ′ -Diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- Screw [4
-(4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4- Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydro Anthracene, 2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 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-phenyleneisopropylidene) bisaniline, 4,4'-(m-phenyleneisopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl Hexafluoropropane, 4,4'-diamino-2,2'-
Aromatic diamines such as bis (trifluoromethyl) biphenyl and 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl;

1,1-meta-xylylenediamine, 1,3
-Propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclo Pentadienylenediamine, hexahydro-4,7-methanoindanylene dimethylenediamine, tricyclo [6,2,1,02.7]-
Aliphatic and cycloaliphatic diamines such as undecylenedimethyldiamine, 4,4'-methylenebis (cyclohexylamine);

A monosubstituted phenylenediamine represented by the following formula (III); a diaminoorganosiloxane represented by the following formula (IV):

[0022]

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(Wherein R ⁵ represents —O—, —COO—,
OCO-, -NHCO-, -CONH- and -CO-
And R ⁶ represents a monovalent organic group having a steroid skeleton or a trifluoromethyl group. )

[0024]

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(Wherein R ⁷ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ^{7 s} may be the same or different, p is an integer of 1 to 3, and q is 1-2
It is an integer of 0. )

Compounds represented by the following formulas (9) to (13) can be exemplified. These diamine compounds can be used alone or in combination of two or more.

[0027]

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(In the formula, y is an integer of 2 to 12, and z is an integer of 1 to 5.)

Of these, p-phenylenediamine,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4'-diaminodiphenylether, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, 9,9-bis (4-
Aminophenyl) fluorene, 2,2-bis [4-
(4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m- (Phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) Biphenyl, compounds represented by the above formulas (9) to (13), and compounds represented by the following formulas (14) to (19) are preferable among the compounds represented by the above formula (III). These diamines may be used as they are, or may be used after being reduced again.

[0030]

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The ratio of the tetracarboxylic dianhydride and the diamine compound used for the synthesis reaction of the polyamic acid is such that the amount of the acid contained in the tetracarboxylic dianhydride is based on 1 equivalent of the amino group contained in the diamine compound. The ratio is preferably 0.2 to 2 equivalents of the anhydride group, more preferably 0.3 to 1.4 equivalents. In both cases where the ratio of the acid anhydride groups contained in the tetracarboxylic dianhydride is less than 0.2 equivalent or more than 2 equivalents, the molecular weight of the obtained polymer becomes too small and the application of the liquid crystal aligning agent is performed. The properties may be poor.

The polyamic acid constituting the liquid crystal aligning agent in the present invention is synthesized by reacting a tetracarboxylic dianhydride with a diamine compound. The synthesis reaction of the polyamic acid is carried out in an organic solvent under a temperature condition of usually 0 to 150 ° C, preferably 0 to 100 ° C. Reaction temperature is 0
When the temperature is lower than or equal to ° C, the solubility of the compound in a solvent may be inferior. When the temperature exceeds 150 ° C, the molecular weight of the obtained polymer may decrease.

The organic solvent used for the synthesis of the polyamic acid is not particularly limited as long as it can dissolve the tetracarboxylic dianhydride, the diamine compound and the polyamic acid formed by the reaction. For example, γ-butyrolactone, N Aprotic systems such as -methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, tetramethylurea, hexamethylphosphoryltriamide, 1,3-dimethyl-2-imidazolidinone Polar solvents; phenolic solvents such as m-cresol, xylenol, phenol, halogenated phenol and the like can be mentioned.

The amount (A) of the organic solvent used is such that the total amount (B) of the tetracarboxylic dianhydride and the diamine compound as the reaction raw materials is 0.1 to 3 with respect to the total amount (A + B) of the reaction solution.
Preferably, the amount is 0% by weight.

The organic solvent includes alcohols, ketones, esters, and the like, which are poor solvents for polyamic acid.
Ethers, halogenated hydrocarbons, hydrocarbons and the like can be used in combination as long as the generated polyamic acid does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol,
Triethylene glycol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate,
Diethyl malonate, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, 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, ethylene Glycol methyl ether acetate, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether Le, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, ethylene glycol ethyl ether acetate, 4
-Hydroxy-4-methyl-2-pentanone, ethyl 2-hydroxypropionate, ethyl lactate, methyl lactate,
Butyl lactate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-
Methyl methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-methyl-3-methoxybutanol, 3-ethyl-3-methoxybutanol, 2-methyl-2-methoxybutanol,
2-ethyl-2-methoxybutanol, 3-methyl-3
-Ethoxybutanol, 3-ethyl-3-ethoxybutanol, 2-methyl-2-ethoxybutanol, 2-ethyl-2-ethoxybutanol, tetrahydrofuran,
Dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-
Examples thereof include dichlorobenzene, hexane, heptane, octane, benzene, toluene, and xylene. These can be used alone or in combination of two or more.

By the above synthesis reaction, a polymer solution obtained by dissolving the polyamic acid is obtained. The polymer solution is poured into a large amount of a poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a polyamic acid. Further, the polyamic acid can be purified by dissolving the polyamic acid in an organic solvent again and then performing the step of precipitating with a poor solvent once or several times.

<(A-2) Imidized polymer> The imidized polymer constituting the liquid crystal aligning agent of the present invention is obtained by the following method (1)
To (3). The imidized polymer is usually a polyimide and / or polyisoimide, with polyimide being more preferred. Further, a polymer in which a part of the repeating unit of the polyamic acid is dehydrated and ring-closed, that is, a polymer having a so-called imidization ratio of not 100% is also included in the imidized polymer, and is suitably used as the liquid crystal aligning agent of the present invention. The term "imidation ratio" used herein indicates the percentage of the repeating unit having an imide ring in the repeating units of the entire polymer, expressed as a percentage.

Method (1): A method of heating a polyamic acid to effect dehydration ring closure. The reaction temperature in this method is usually
The temperature is 60 to 200 ° C, preferably 100 to 170 ° C. When the reaction temperature is lower than 60 ° C., the imidization reaction does not proceed sufficiently, and when the reaction temperature is higher than 200 ° C., the molecular weight of the specific polymer (II) obtained may be small.

Method (2): A method in which a polyamic acid is dissolved in an organic solvent, a dehydrating agent and an imidization catalyst are added to the solution, and the solution is heated if necessary. In this method, an acid anhydride such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is preferably 1.6 to 20 mol per 1 mol of the repeating unit of the polyamic acid.
Further, as the imidation catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but are not limited thereto. The amount of the imidation catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the imidization reaction, the organic solvents exemplified as those used for the synthesis of the polyamic acid can be exemplified. And the reaction temperature of the imidization reaction is usually 0 to 180 ° C, preferably 60 to 150 ° C.

Method (3): A method in which tetracarboxylic dianhydride and a diisocyanate compound are mixed and condensed.
Specific examples of the diisocyanate compound used in this method include: an aliphatic diisocyanate compound such as hexamethylene diisocyanate; an alicyclic diisocyanate compound such as cyclohexane diisocyanate; diphenylmethane-4,4'-diisocyanate, diphenylether-4,4'- Diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate, 1,2-diphenylethane-p, p'-diisocyanate, 2,2-diphenylpropane-p, p'-diisocyanate, 2,2-diphenyl-1,1,1,3,3,3-hexafluoropropane-p, p'-diisocyanate, 2,2-diphenylbutane-p, p'-diisocyanate, diphenyl dichloromethane-4,4 ' -Diisocyanates, diphs Aromatic diisocyanate compounds such as nylfluoromethane-4,4′-diisocyanate, benzophenone-4,4′-diisocyanate, and N-phenylbenzoic acid amide-4,4′-diisocyanate can be given, either alone or Two or more can be used in combination. This method does not require a catalyst, and the reaction temperature is usually 50 to 200 ° C., preferably 100 to 160 ° C.
° C. For the polymer solution thus obtained,
By performing the same operation as the method for purifying a polyamic acid, the imidized polymer can be purified.

<Intrinsic viscosity of polyamic acid and imidized polymer> The intrinsic viscosity of the polyamic acid and imidized polymer obtained as described above (30 ° C, N-methyl-
Measured in 2-pyrrolidone. The same applies hereinafter. ) Is usually 0.05 to 10 dl / g, preferably 0.05 to 5 dl.
/ G.

<Terminal-Modified Polymer> The polyamic acid and / or imidized polymer constituting the liquid crystal aligning agent of the present invention may be a terminal-modified polymer. The molecular weight of the terminal-modified polymer is controlled, and the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. The terminal-modified polymer can be synthesized by adding an acid anhydride, a monoamine compound, or a monoisocyanate compound to the reaction system when synthesizing the polyamic acid.

The acid anhydride to be added to the reaction system for synthesizing the polyamic acid to obtain a terminal-modified polymer includes, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic acid Anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl succinic anhydride and the like can be mentioned. Examples of the monoamine added to the reaction system include, for example, aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosyl Alkylamines such as amines; 3-aminopropylmethyldiethoxysilane, 3- [N-allyl-N- (2-aminoethyl)] aminopropyltrimethoxysilane, N- (2
-Aminoethyl) -3-aminopropylmethyldimethoxysilane, N-[(3-trimethoxysilyl) propyl] diethylenetriamine and the like.
In addition, examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

<Compound (i)> The liquid crystal aligning agent of the present invention comprises:
By containing the compound represented by the above formula (i),
The leveling property during application and firing of the liquid crystal alignment agent is improved,
A liquid crystal alignment film with few surface irregularities can be formed. As a result, a liquid crystal display element obtained by using the liquid crystal alignment film has excellent display performance with no display failure.

In the above formula (i), A ^{1 to} A ^{11 each} represent an alkyl group or a hydrogen atom.
An alkyl group having 1 to 6 carbon atoms is preferred. Specific examples of the compound (i) include a novel compound obtained by adding ethylene glycol monoesters to γ-butyrolactone and performing a ring-opening reaction. These compounds can be used alone or in combination of two or more. The compound (i) used in the liquid crystal aligning agent of the present invention preferably has a boiling point of 200 ° C. or higher at normal pressure.
Those having a temperature of 250 ° C. or higher are particularly preferred. Boiling point at normal pressure 200
If the temperature is lower than 0 ° C, the liquid crystal aligning agent is volatilized too quickly during firing, and a sufficient leveling effect may not be obtained.

<Compound (ii)> The liquid crystal aligning agent of the present invention comprises:
By containing a compound and / or a polymer having the structure represented by the above formula (ii), the adhesion between the obtained liquid crystal alignment film and the substrate is improved, and the film is prevented from peeling and rubbing during rubbing. In addition, a liquid crystal alignment film having few surface irregularities can be formed. As a result, a liquid crystal display element obtained by using the liquid crystal alignment film can have excellent display performance without display defects.

In the above formula (ii), A ^{12 to} A ^{14 each} represent an alkyl group or a hydrogen atom.
An alkyl group having 1 to 6 carbon atoms is preferred. Specific examples of compound (ii) include 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldiisopropenoxysilane, N-glycidyl-N, N-bis [3- (methyldimethoxysilyl) ) Propyl] amine,
3-glycidoxypropylmethyldimethoxysilane, 3
-Aminopropylmethyldiethoxysilane, N- (2-
Examples thereof include silane compounds such as (aminoethyl) -3-aminopropylmethyldimethoxysilane, and terminal-modified polymers obtained by binding these silane compounds to polyamic acid or polyimide terminals. These compounds (ii) can be used alone or in combination of two or more.

<Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention is selected from the component (a) consisting of polyamic acid and / or an imidized polymer of polyamic acid, and the above compounds (i) and (ii) [ b) component is dissolved and contained in an organic solvent. When a terminal-modified polymer is used as compound (ii), polyamic acid and / or
Alternatively, the above silane compound may be added during the synthesis of the imidized polymer, and a part of the polymer may be used as a terminal-modified polymer.

The content ratio (polymer concentration) of the component (a) in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, and the like.
20% by weight, more preferably 0.5 to 10% by weight
It is said. When the concentration is less than 0.1% by weight, the thickness of the coating film (coating) becomes too small to obtain a good liquid crystal alignment film, while the concentration exceeds 20% by weight. In such a case, the film thickness of the coating film becomes excessively large, making it difficult to obtain a good liquid crystal alignment film. In addition, the viscosity of the liquid crystal alignment agent is increased, and the coating properties may be deteriorated. As the content ratio of the component (b) in the liquid crystal alignment agent of the present invention, the ratio of the component (b-1) to 100 parts by weight of the component (a) is usually 0.01 to 20 parts by weight, preferably 0.1 to 20 parts by weight. 1 to 10
Parts by weight. If the amount is less than 0.01 part by weight, the leveling effect may not be sufficiently exhibited. If the amount exceeds 20 parts by weight, a large amount of the component (b-1) remains in the alignment film, resulting in poor alignment characteristics. There are cases. In the case of a silane compound, the proportion of the component (b-2) is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight. In the case of a polymer having a silane compound introduced at the terminal, Si in the polymer is used.
The amount is between 0.1 and 10% by weight, preferably between 0.5 and 5% by weight. When the amount is less than 0.1 part by weight, the effect of improving the adhesion between the obtained liquid crystal alignment film and the substrate may not be sufficiently exhibited. In some cases, it is eluted in and deteriorates the display characteristics of the liquid crystal display device. Further, in the liquid crystal aligning agent of the present invention, the compound (i) which is the component [b-1] and the compound [b-
2) A higher effect can be obtained by using the compound (ii) as the component in combination. Note that [a]
As the organic solvent for dissolving the component and the component (b),
The solvent is not particularly limited as long as it can dissolve them, and examples thereof include the solvents exemplified as those used in the synthesis of polyamic acid. In addition, the poor solvents exemplified as those which can be used together in the synthesis reaction of the polyamic acid can be appropriately selected and used in combination.

The liquid crystal aligning agent of the present invention has a compound (i) for the purpose of further improving the adhesion to the substrate.
Epoxy group-containing compounds other than i) may be contained. Such epoxy group-containing compounds include, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1.6 Hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,
3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ', N',-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) Cyclohexane, N, N, N ', N',-tetraglycidyl-4,4'-diaminodiphenylmethane, 3-
(N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane and the like can be mentioned.
Of these, compounds having a tertiary nitrogen atom in the molecule are preferred.The compounding ratio of these epoxy group-containing compounds is usually 40 parts by weight or less, preferably 0.1 part by weight, per 100 parts by weight of the component (a). 1 to 30 parts by weight.

<Liquid crystal display device> A liquid crystal display device obtained by using the liquid crystal aligning agent of the present invention can be produced, for example, by the following method. (1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method, or a printing method, and then the applied surface is heated. This forms a coating. Here, as the substrate, for example, a transparent substrate made of glass such as float glass or soda glass; or a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, or polycarbonate can be used. Further, as a transparent conductive film provided on one surface of the substrate, a NESA film (registered trademark of US PPG) made of tin oxide (SnO ₂ ) and an ITO made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ )
A film or the like can be used, and a photo-etching method or a method using a mask in advance is used for patterning these transparent conductive films. When applying the liquid crystal aligning agent,
In order to further improve the adhesion between the surface of the substrate and the transparent conductive film and the film of the liquid crystal alignment agent, a functional silane-containing compound, a functional titanium-containing compound, or the like may be applied to the surface of the substrate in advance. The heating temperature is 80-250 ° C
And preferably 120 to 200 ° C. The film thickness of the formed film is usually from 0.001 to 1 μm, and preferably from 0.005 to 0.5 μm. In addition, the liquid crystal alignment agent of the present invention containing a polyamic acid forms a film to be a liquid crystal alignment film by removing an organic solvent after coating, but further heats the dehydration ring closure to partially imidize. Alternatively, it may be a completely imidized film.

(2) A rubbing treatment is performed in which the surface of the coating formed by the liquid crystal aligning agent is rubbed in a certain direction with a roll around which a cloth made of fibers such as nylon, rayon, cotton or the like is wound. As a result, the alignment ability of liquid crystal molecules is imparted to the film, and a liquid crystal alignment film is formed. In addition to the method using a rubbing treatment, a method of imparting alignment ability by irradiating the surface of the resin film with polarized ultraviolet light, an ion beam, an electron beam, or the like,
The liquid crystal alignment film can also be formed by a method of obtaining a film by a uniaxial stretching method, a Langmuir-Blodgett method, or the like. Fine powder (foreign matter) generated during rubbing
It is preferable that the formed liquid crystal alignment film is washed with isopropyl alcohol or the like in order to remove the impurities and keep the surface in a clean state. Further, a process of changing the pretilt angle by partially irradiating the surface of the formed liquid crystal alignment film with ultraviolet rays, an ion beam, an electron beam, or the like (for example, JP-A-6-222366, JP-A-6-2819)
37, JP-A-7-168187, JP-A-8
JP-A-234207), a resist film is partially formed on the surface of the formed liquid crystal alignment film, and a rubbing process is performed in a direction different from the preceding rubbing process. A treatment for changing the alignment ability of the alignment film (see, for example, JP-A-5-107544).
Is performed, the viewing angle characteristics of the manufactured liquid crystal display element can be improved.

(3) Two substrates on which the liquid crystal alignment films are formed as described above are prepared, and the two substrates are oriented such that the alignment treatment directions in each liquid crystal alignment film, ie, the rubbing directions are orthogonal or antiparallel. Substrates are arranged to face each other with a gap (cell gap) therebetween, the peripheral portions of the two substrates are bonded together with a sealant, and liquid crystal is injected and filled into the substrate surface and the cell gap defined by the sealant. Then, the injection hole is sealed to form a liquid crystal cell. Then, a polarizing plate is provided on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. Thus, a liquid crystal display element is obtained.

Here, as the sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, a nematic liquid crystal is preferable. For example, a Schiff base liquid crystal, an azoxy liquid crystal,
Biphenyl-based liquid crystal, phenylcyclohexane-based liquid crystal, ester-based liquid crystal, terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal, cubane-based liquid crystal, and the like can be used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate, and chiral agents such as those sold under the trade names "C-15" and "CB-15" (manufactured by Merck & Co.) It can also be used by adding it. Further, p-decyloxybenzylidene-p
Ferroelectric liquid crystals such as -amino-2-methylbutylcinnamate can also be used. Further, as a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing plate or an H film in which a polarizing film called an H film absorbing iodine is sandwiched by a cellulose acetate protective film while stretching and aligning polyvinyl alcohol. A polarizing plate composed of itself can be mentioned.

[0055]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The evaluation items and evaluation methods of the liquid crystal aligning agents prepared in the following Examples and Comparative Examples are shown below. [Orientation of Liquid Crystal] The presence or absence of abnormal domains in the liquid crystal cell when the voltage was turned on / off in the liquid crystal display element was observed with a microscope, and the case where there was no abnormal domain was judged as “good”. [Adhesion of Liquid Crystal Alignment Film] The liquid crystal alignment film obtained after applying and drying a liquid crystal alignment agent on a substrate is boiled with water for 1 hour, and the film obtained by wiping off water droplets is subjected to a grid test according to JIS K-5400. The adhesion was evaluated by the number of grids that did not peel out of the 100 grids. A rating of 90 or more was evaluated by a three-point scale of ○, 70 or more and less than 90, Δ, and less than 70, ×. [Surface smoothness of coating film] Flexographic printing of a liquid crystal aligning agent on a 30 cm square ITO solid substrate using a Nakan printing machine,
Baking at 180 ° C. for 1 minute and then at 180 ° C. for 1 hour to form a liquid crystal alignment film. Using a stylus type film thickness meter, determine the average film thickness and the difference (variation) between the maximum film thickness and the minimum film thickness. It was measured.

Synthesis Example 1 224.17 g (1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 97.33 g (0.9 mol) of p-phenylenediamine and cholesteryl 3,5-diaminobenzoate ( 52.08 g (0.1 mol) of the compound represented by the above formula (14) was dissolved in 2100 g of N-methyl-2-pyrrolidone, and
Allowed to react for hours. Then, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product, a solid substance was separated, washed with acetone, and dried at 40 ° C. under reduced pressure for 15 hours. 30.0 g of the obtained polymer was dissolved in 570 g of γ-butyrolactone, and 32 g of pyridine and 2 g of acetic anhydride were dissolved.
4 g was added and a dehydration ring closure reaction was performed at 110 ° C. for 4 hours. Thereafter, the reaction product is precipitated, separated, washed and dried to obtain a logarithmic viscosity (ηln) of 1.36 dl / g,
27.3 g of a polyimide having an imidation ratio of 95% (hereinafter referred to as “polymer (A)”) was obtained.

Synthesis Example 2 1,3,3a, 4,5,9b-Hexahydro-8-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione 31
4.30 g (1 mol), p-phenylenediamine
88 g (0.85 mol) and 63.36 g (0.15 mol) of the compound represented by the above formula (18) were treated with N-methyl-
Dissolve in 1900 g of 2-pyrrolidone and add this solution to 20
Reaction was performed at 26 ° C. for 26 hours. Then, the reaction product was precipitated, separated, washed, and dried in the same manner as in Synthesis Example 1, 30.0 g of the obtained polymer was dissolved in 270 g of γ-butyrolactone, and 20 g of pyridine and 45 g of acetic anhydride were added thereto.
The dehydration ring closure reaction was performed at 0 ° C. for 4 hours. Then, Synthesis Example 1
The reaction product is precipitated, separated, washed and dried in the same manner as described above to obtain a polyimide having a logarithmic viscosity (ηln) of 1.06 dl / g and an imidation ratio of 100% (hereinafter referred to as “polymer (B)”).
28.3 g).

Synthesis Example 3 In Synthesis Example 2, p-phenylenediamine 91.88
g (0.85 mol) was changed to 29.75 g (0.15 mol) of 4,4'-diaminodiphenylmethane and 75.67 g (0.7 mol) of p-phenylenediamine in the same manner as in Synthesis Example 2. Logarithmic viscosity (ηln) 1.0
dl / g, imidation rate 100% polyimide (hereinafter, referred to as
25.3 g) was obtained.

Synthesis Example 4 Pyromellitic dianhydride 109.05 g (0.5 mol), cyclobutanetetracarboxylic anhydride 98.05
g (0.5 mol) and 198.27 g (1 mol) of 4,4'-diaminodiphenylmethane were dissolved in 1600 g of N-methyl-2-pyrrolidone.
Allowed to react for hours. Then, by precipitating, separating, washing and drying the reaction product in the same manner as in Synthesis Example 1, a polyamic acid having a logarithmic viscosity (ηln) of 1.8 dl / g (hereinafter, referred to as “polyamic acid”).
400.3 g of "polymer (D)" was obtained.

Synthesis Example 5 224.17 g (1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 432.5 g of bis [4- (4-aminophenoxy) phenyl] sulfone
(1 mol) was dissolved in 6000 g of γ-butyrolactone, and the solution was reacted at 60 ° C. for 6 hours. Then, the reaction product is precipitated, separated, washed and dried in the same manner as in Synthesis Example 1 to obtain a polyamic acid having a logarithmic viscosity (ηln) of 1.5 dl / g (hereinafter referred to as “polymer (E)”). 65
0 g was obtained.

Synthesis Example 6 In Synthesis Example 2, p-phenylenediamine 91.88
g (0.85 mol) of p-phenylenediamine 86.
The logarithmic viscosity (ηln) was the same as in Synthesis Example 2 except that the amount was changed to 47 g (0.8 mol) and 19.09 g (0.05 mol) of 3-aminopropylmethyldiethoxysilane.
25 g of 0.94 dl / g polyimide having an imidization ratio of 100% (hereinafter referred to as “polymer (F)”) was obtained. When the amount of unreacted 3-aminopropylmethyldiethoxysilane was examined by gas chromatography, it was not detected.
It was confirmed that -aminopropylmethyldiethoxysilane was in a state of being chemically bonded in the polymer.

Synthesis Example 7 In Synthesis Example 4, 198.27 g (1 mol) of 4,4'-diaminodiphenylmethane was replaced by 190.41 g (0.95 mol) of 4,4'-diaminodiphenylmethane and 3-aminopropylmethyldimethane. Ethoxysilane 19.31
In the same manner as in Synthesis Example 4 except that the amount was changed to g (0.05 mol), 410 g of a polyamic acid (hereinafter, referred to as “polymer (G)”) having an intrinsic viscosity (ηln) of 2.0 dl / g was obtained. . The amount of unreacted 3-aminopropylmethyldiethoxysilane was not detected by examining the amount of unreacted 3-aminopropylmethyldiethoxysilane by gas chromatography.
It was confirmed that the polymer was chemically bonded.

Synthesis Example 8 10 g of γ-butyrolactone and 13.7 butyl cellosolve
To the mixed solution of g, 0.2 g of triethylamine was added, and the mixture was refluxed for 6 hours. Unreacted γ-butyrolactone, butyl cellosolve, and triethylamine were distilled off under reduced pressure to obtain 3 g of a compound represented by the following formula (i-1).
¹ H NMR chart of the obtained compound (solvent: CDC
l ₃ ) is shown in FIG.

[0064]

Embedded image

Example 1 100 parts by weight of the polymer (A) obtained in Synthesis Example 1, 1 part by weight of the compound represented by the above formula (i-1) obtained in Synthesis Example 8, and 3-glycidoxypropyl One part by weight of methyldiethoxysilane was dissolved in γ-butyrolactone to form a solution having a solid concentration of 4% by weight, and this solution was filtered with a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent. The above liquid crystal aligning agent was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film by using a liquid crystal alignment film coating printer, and 18
The coating was dried on a hot plate at 0 ° C. for 20 minutes to form a coating having a dried average film thickness of 900 °. The difference between the maximum film thickness and the minimum film thickness was 150 °, and the evaluation of adhesion was ○. Using a rubbing machine having a roll in which a rayon cloth is wound around this film, the number of rotations of the roll is 500 rpm, the moving speed of the stage is 1 cm / sec, and the push-in length of hair is 0.4.
Rubbing treatment was performed in mm. The alignment film coated substrate,
After immersion in isopropyl alcohol for 1 minute, both substrates were dried on a hot plate at 100 ° C. for 5 minutes.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is screen-printed and applied to each of the outer edges of the pair of rubbed liquid crystal holding substrates having the liquid crystal alignment film, and then the pair of liquid crystal holding substrates is subjected to liquid crystal. The adhesive was cured by overlapping and pressing so that the alignment film surfaces face each other and the rubbing direction was perpendicular. Next, a nematic type liquid crystal (MLC-5081 manufactured by Merck) is filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photocuring adhesive. The polarizing plates were adhered so that the polarizing direction of the polarizing plates coincided with the rubbing direction of the liquid crystal alignment films of the respective substrates, thereby producing a liquid crystal display device. When the orientation of the liquid crystal of the obtained liquid crystal display device was evaluated, the orientation of the liquid crystal was good. Table 1 shows the results.

Examples 2 to 12 and Comparative Examples 1 and 2 According to the formulations shown in Table 1, the polymers and additives obtained in Synthesis Examples 1 to 7 were used to prepare liquid crystal aligning agents in the same manner as in Example 1. did. Next, a liquid crystal display device was produced in the same manner as in Example 1 using the liquid crystal aligning agent thus obtained. For each of the obtained liquid crystal aligning agent and the liquid crystal display element, the alignment of liquid crystal, the adhesiveness, the thickness of the alignment film and its variation were evaluated. Table 1 shows the results.

[0067]

[Table 1]

In Table 1, each additive is as follows. (I-1) Compound represented by the above formula (i-1) (ii-1) 3-glycidoxyfluoromethylmethylethoxysilane (ii-2) N-glycidyl-N, N-bis [3- (methyl (Methoxysilyl) fluoropropyl] amine (iii-1) N, N, N ', N'-tetraacrylicyl-4,4'-diaminoaminophenylmethane

[0069]

According to the liquid crystal aligning agent of the present invention, in the case of a liquid crystal display device, the formed alignment film is excellent in smoothness and adhesion, so that it is hardly affected by adsorbed ions. Therefore, it is possible to obtain a liquid crystal display element having no alignment defect.
The liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be suitably used for TN type and STN type liquid crystal display devices, and can be further provided by selecting SH (Super Homeotropic) by selecting a liquid crystal to be used. ) Type, IPS (In
-Plane Switching) type, ferroelectric and antiferroelectric liquid crystal display devices, etc. Furthermore, a liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be effectively used for various devices, for example, a desk calculator, a wristwatch, a clock, a coefficient display plate,
It is used for display devices such as word processors, personal computers, and liquid crystal televisions.

[Brief description of the drawings]

FIG. 1 is an NMR chart of a compound represented by the formula (i-1) used in Examples of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/1337 525 G02F 1/1337 520 C08K 5/101 C08L 79/08

Claims (2)

(57) [Claims] 1. [a] at least one polymer selected from a polyamic acid and an imidized polymer of a polyamic acid, and [b-1] the following formula (i): (Wherein, A ^{1 to} A ¹¹ each independently represent an alkyl group or a hydrogen atom). 2. [a] at least one polymer selected from polyamic acids and imidized polymers of polyamic acids, and [b-2] the following formula (ii): (Wherein, A ^{12 to} A ¹⁴ each independently represent an alkyl group or a hydrogen atom.) A compound and / or a polymer having a structure represented by the following formula: