TWI477479B - Benzene diamine, polymer, composition for alignment film, alignment film, and liquid crystal display device - Google Patents

Description

Diamine benzene compound, polymer, composition for alignment film, alignment film, and liquid crystal display element

The present invention relates to a diamine compound, and more particularly to a diamine benzene compound, a polymer obtained by reacting the diamine benzene compound as a starting material, a composition for an alignment film containing the polymer, and a use thereof. An alignment film made of the composition for an alignment film and a liquid crystal display element including the alignment film.

The operation principle of the liquid crystal display is to change the alignment state of the liquid crystal molecules by using an external electric field, thereby causing the polarization state and direction of the light to change, thereby obtaining a display effect of light and dark contrast. Due to its small size, light weight, low power consumption and good display quality, liquid crystal displays have become the mainstream of flat panel displays in recent years.

As the size of the screen has expanded, liquid crystal display elements having thin filmed transistors (TFTs) in each of the pixels have been developed. When liquid crystal molecules are placed between a pair of substrates containing electrodes, since the liquid crystals have different electric induction rates in the direction of parallel and perpendicular molecules, the arrangement of liquid crystal molecules can be controlled by controlling the electric field. On the other hand, since the liquid crystal molecules have birefringence characteristics, the polarization direction of the polarized light can be regulated by the change in the alignment state of the liquid crystal molecules.

In order to allow the liquid crystal molecules to have a uniform tilt angle and a fixed orientation on the substrate, an alignment film is coated on the substrate, and the alignment film is used to control the alignment direction of the liquid crystal molecules and provide a stable pretilt angle of the liquid crystal molecules, and when added When the electric field is turned off, the liquid crystal molecules return to the original arrangement by the anchoring force at the interface with the alignment film and its own elasticity.

At present, a typical method for preparing an alignment film in the industry is to apply an organic film on the surface of a substrate, and the molecules on the surface of the film are oriented by friction or other means, thereby allowing the subsequently placed liquid crystal molecules to be tilted in a fixed direction. The material of the organic film may be selected from the group consisting of polyvinyl alcohol, polyethylene glycol, polyamidamine, polyaminic acid or polyimine, wherein the polyamic acid and the polyimide have excellent thermal stability and good mechanical properties. Electrical and chemical resistance are often used as alignment film materials. Polylysine is a polymer obtained by polymerization of a diamine and a tetracarboxylic acid or a diamine and a tetracarboxylic dianhydride, and the polyimine is generally subjected to a high temperature dehydration ring closure reaction by polyamic acid. Made by.

The voltage holding ratio is related to the case where the voltage of the liquid crystal display element is decremented in the open state. For an active array driven liquid crystal display element, when a pixel temporarily does not display a picture, the circuit of the pixel will be in an open state and start to discharge. If the voltage holding rate of the element is not high, between the electrodes The voltage value will decrease instantaneously, causing the alignment of the liquid crystal molecules to become messy, resulting in poor image quality. Therefore, in order to present high-quality images, the voltage retention rate is an important index, which must be high and uniform.

The present invention provides a diamine benzene compound, a polymer obtained by reacting the diamine benzene compound as a starting material, a composition for an alignment film containing the polymer, an alignment film produced using the composition for an alignment film, and A liquid crystal display element including the alignment film. The diamine benzene compound has a high polarity, and therefore, the liquid crystal display element has an excellent voltage holding ratio.

A diamine benzene compound of the present invention is represented by Formula 1: H ₂ N-Ar-NH ₂ Formula 1, wherein Ar is as shown in Formula 2: Wherein * is a position in which the group represented by Formula 2 and the two -NH ₂ groups of Formula 1 are bonded; R _{1 is} each independently, and is a hydrogen atom or a monovalent substituent other than the primary amine group; X ₁ is included or a divalent linking group; R ₂ is a divalent linking group including a benzene ring or a cyclohexane ring, wherein the hydrogen of the benzene ring or the cyclohexane ring may independently pass through a C ₁ -C ₃ alkyl group, F, Cl , -OH or -CN substituted; X ₂ and X ₃ are each a C ₁ -C ₃ linear alkylene group; and R ₃ is a monovalent substituent including a benzene ring or a cyclohexane ring, wherein the benzene ring or cyclohexane The hydrogen of the alkane may be independently substituted with C ₁ -C ₃ alkyl, F, Cl, -OH or -CN.

In an embodiment of the invention, R ₂ is an aromatic group.

In an embodiment of the invention, R ₂ is a group represented by Formula 3: Wherein Q ₁ to Q ₄ are each a hydrogen atom or a C ₁ -C ₃ alkyl group.

In an embodiment of the invention, R ₃ is a group represented by Formula 4: Wherein Q ₅ to Q ₉ are each a hydrogen atom or a C ₁ -C ₃ alkyl group.

In an embodiment of the invention, the diamine benzene compound is represented by Formula 5:

The polymer of the present invention having a guanamine bond, an oxime bond or a combination of the foregoing, includes a unit represented by any one of Formulas 6 to 9: Wherein G ₁ is a C ₂ -C ₃₀ aliphatic tetracarboxylic acid residue, an alicyclic tetracarboxylic acid residue or an aromatic tetracarboxylic acid residue, and G ₂ is a C ₂ -C ₃₀ aliphatic tricarboxylic acid residue a alicyclic or alicyclic residue or an aromatic tricarboxylic acid residue, and G ₃ is a C ₂ - C ₃₀ aliphatic dicarboxylic acid residue, an alicyclic dicarboxylic acid residue or an aromatic dicarboxylic acid. The residue, R ₄ each independently, is a hydrogen atom or a C ₁ - C ₂₀ alkyl group, and Ar in the formula 6 to formula 9 is a residue of the aforementioned diamine benzene compound.

In an embodiment of the invention, the unit represented by any one of Formulas 6 to 9 accounts for 5 mole percent to 99 mole percent of the polymer.

The composition for an alignment film of the present invention includes the above polymer having a guanamine bond, a ruthenium bond or the above two bonds.

The alignment film of the present invention is obtained from the above-described composition for an alignment film.

The liquid crystal display element of the present invention comprises the aforementioned alignment film.

Based on the above, the present invention provides a diamine benzene compound, a polymer having a guanamine bond and/or a ruthenium bond bond prepared therefrom, a composition for an alignment film comprising the polymer, and a composition for using the alignment film The resulting alignment film and liquid crystal display element. The diamine benzene compound has a high polarization parameter, and therefore, the liquid crystal display element has an excellent voltage holding ratio, and can effectively solve the afterimage problem of the liquid crystal display element.

The above described features and advantages of the present invention will be more apparent from the following description.

1 to 4 are NMR spectrum patterns of products of each step in the synthesis example.

The embodiments are further enumerated below to further illustrate various aspects of the invention. In the present specification, if a group is not specifically indicated, whether or not a group is substituted, the group may represent a substituted or unsubstituted group. For example, "alkyl" can mean a substituted or unsubstituted alkyl group. Further, when a group crown is described by "C _X ", it means that the main chain of the group has X carbon atoms.

Herein, the structure of the compound is sometimes represented by a skeleton formula. This representation can omit carbon atoms, hydrogen atoms, and carbon-hydrogen bonds. Of course, if the functional group is clearly drawn in the structural formula, the manufacturer will prevail.

In the present specification, the range indicated by "a numerical value to another numerical value" is a schematic representation that avoids enumerating all the numerical values in the range in the specification. Therefore, the recitation of a particular range of values is intended to include any value in the range of values and the range of values defined by any value in the range of values, as in the specification. The range of values is the same. For example, the range of "temperature is 80 ° C to 300 ° C" covers the range of "temperature is 100 ° C to 250 ° C" regardless of whether other values are listed in the specification.

A first embodiment of the present invention provides a diamine benzene compound represented by Formula 1: H ₂ N-Ar-NH ₂ Formula 1, Ar is a residue of a diamine benzene compound represented by Formula 1, as shown in Formula 2 : Where * is the position at which the group represented by Formula _{2 is} bonded to the two -NH _{2 of} Formula 1.

In the present embodiment, R _{1 is} each independently and may be a hydrogen atom or a monovalent substituent other than the primary amine group; X ₁ may be included or a divalent linking group; R ₂ may be a divalent linking group including a benzene ring or a cyclohexane ring, wherein the hydrogen of the benzene ring or the cyclohexane ring may independently be a C ₁ -C ₃ alkyl group, F , Cl, -OH or -CN substituted; X ₂ and X ₃ may each be a C ₁ -C ₃ linear alkyl group, for example, an ethyl group; R ₃ may be a monovalent substitution including a benzene ring or a cyclohexane ring. The group wherein the hydrogen of the benzene ring or cyclohexane is independently substituted with C ₁ -C ₃ alkyl, F, Cl, -OH or -CN.

In the present embodiment, when the alkyl group is substituted, the preferred aspect is fluorine substitution.

By a conventional method, a polymer having a guanamine bond and/or a quinone bond can be produced by using the above-mentioned diamine benzene compound, and such a polymer is commonly used to produce an alignment film of a liquid crystal display element. In this regard, the ring structure containing two nitrogen atoms in the aforementioned diamine benzene compound can adsorb impurities at the interface of the alignment film to enhance electrical properties; and if the ring structure is a five- or six-membered ring, the alignment film can be made. The alignment is preferred, that is, X ₂ and X _{3 of the} formula 2 are preferably an ethyl group at the same time, or one of the methylene groups is preferably an ethyl group. Further, X ₁ of Formula 2 brings high polarity to the diamine benzene compound, and thus the voltage holding ratio of the liquid crystal display element can be improved.

In the present embodiment, R ₂ may be an aromatic group such as a group represented by Formula 3: Wherein Q ₁ to Q ₄ are each, for example, a hydrogen atom or a C ₁ -C ₃ alkyl group.

In the present embodiment, R ₃ may also be an aromatic group, for example, represented by Formula 4: Wherein Q ₅ to Q ₉ are each, for example, a hydrogen atom or a C ₁ -C ₃ alkyl group.

Specifically, the diamine benzene compound of the present embodiment can be represented by Formula 5:

The diamine benzene compound in the present embodiment can be synthesized by the following two steps: First, the dinitrobenzene compound represented by Formula I and the piperazine shown by Formula II are present in the presence of a base and an organic solvent. (piperazine) compound is subjected to a substitution reaction to obtain a compound represented by formula III,

Wherein Y ₁ is, for example, -F, -Cl, -Br, -COCl, -COOH, and the like; and Y _{2 is,} for example, -NH ₂ . When Y ₁ is -F, -Cl or -Br and Y ₂ is -NH ₂ , X ₁ obtained by the reaction of the two is -NH-; when Y ₁ is -COCl or -COOH and Y ₂ is -NH ₂ X ₁ obtained by the reaction of the two is -CONH-. R ₁ to R ₃ and X ₁ to X ₃ are the same as defined in Formula 2.

Next, the compound represented by Formula III is subjected to a reduction reaction (hydrogenation reaction) to obtain a diamine benzene compound represented by Formula 1.

In the aforementioned synthesis method, the added base has a catalyst effect, which increases the rate of the synthesis reaction and lowers the reaction temperature. Suitable bases may be basic compounds of Group IA and Group IIA metals, preferably carbonates of Group IA and Group IIA metals. Alternatively, suitable bases can also be tertiary amines such as trimethylamine, triethylamine, triisopropylethylenediamine or the like.

In this synthesis, suitable organic solvents may be alkyl halides (such as dichloromethane, dichloroethane, chloroform or the like), ketones (such as acetone, methyl ethyl ketone or the like), N-methyl. -2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylhydrazine or the like.

The aforementioned reduction reaction (hydrogenation reaction) can be carried out by a conventional hydrogenation reaction method. For example, the reduction reaction is carried out with hydrogen or a hydrazine using platinum (Pt), palladium (Pd), Raney-Ni (Raney-Ni) or a similar metal catalyst at a suitable pressure and temperature. For example, a reduction reaction can be carried out with concentrated hydrochloric acid using tin dichloride (SnCl ₂ ), iron (Fe) or a similar reducing agent. Alternatively, the reaction can be carried out in an aprotic solvent using LiAlH ₄ or a similar reducing agent.

A second embodiment of the present invention provides a polymer having a guanamine bond and/or a quinone bond, which comprises a repeating unit represented by any one of Formulas 6 to 9:

In the present embodiment, G ₁ may be a C ₂ - C ₃₀ aliphatic tetracarboxylic acid residue, an alicyclic tetracarboxylic acid residue or an aromatic tetracarboxylic acid residue, and G ₂ may be C ₂ - C ₃₀ Aliphatic tricarboxylic acid residue, alicyclic tricarboxylic acid residue or aromatic tricarboxylic acid residue, G ₃ may be a C ₂ - C ₃₀ aliphatic dicarboxylic acid residue, an alicyclic dicarboxylic acid Residue or aromatic dicarboxylic acid residue, R ₄ each independently, and may be a hydrogen atom or a C ₁ -C ₂₀ alkyl group, and Ar in the formula 6 to formula 9 is as defined in Formula 2.

The repeating unit represented by Formula 6 is produced, for example, by reacting the diamine benzene compound of the first embodiment with a tetracarboxylic acid or a dianhydride compound thereof. The repeating unit represented by Formula 7 is obtained by dehydration cyclization of the repeating unit represented by Formula 6. As for the repeating unit represented by Formula 8 and Formula 9, it can be produced by reacting the diamine benzene compound of the first embodiment with a tricarboxylic acid or a dicarboxylic acid or a derivative thereof. The reaction of an amine group with an acid group to form a guanamine bond, or a dehydration cyclization of a guanamine bond to form a quinone bond, is well known to those of ordinary skill in the art. The synthesis of the repeating unit represented by Formula 6 and the repeating unit represented by Formula 7 will be briefly described below, and the rest of the details will not be described again.

The tetracarboxylic acid to be used is not particularly limited, and for example, an aromatic tetracarboxylic acid, an aliphatic cyclic tetracarboxylic acid, an aliphatic tetracarboxylic acid or a dianhydride thereof, and a divalent halogen compound of a dicarboxylic acid can be used. Further, the tetracarboxylic acid may be used singly or in combination of two or more.

The aromatic tetracarboxylic acid is, for example, 1,2,4,5-benzenetetracarboxylic acid, 3,3',4,4'-diphenyltetracarboxylic acid, 2,3,3',4-diphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl)ether, 3,3'4,4'-benzophenonetetracarboxylic acid, bis(3, 4-dicarboxyphenyl)anthracene, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3, 3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethyloxane, bis(3,4-dicarboxyphenyl)di Phenyl decane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, dianhydride derived from the above aromatic tetracarboxylic acid and dicarboxylic acid A halogen compound or the like.

The aliphatic cyclic tetracarboxylic acid is, for example, cyclobutanetetracarboxylic acid, cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, 1,3,5-tricarboxycyclopentyl acetic acid, 3,4-dicarboxy- 1,2,3,4-tetrahydro-1-naphthalene succinic anhydride, a dianhydride derived from the above aliphatic cyclic tetracarboxylic acid, and a divalent halogen compound of dicarboxylic acid or the like.

The aliphatic tetracarboxylic acid is, for example, butanetetracarboxylic acid or a dianhydride thereof derived therefrom and a divalent halogen compound of a dicarboxylic acid.

The polymerization method of the diamine benzene compound and the tetracarboxylic acid or its dianhydride compound is not particularly limited and can be carried out by a known method. For example, the diamine benzene compound is first dissolved in an organic polar solvent (eg, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl Kea 碸). Next, a tetracarboxylic acid or a dianhydride compound thereof is added to the solvent to carry out a polymerization reaction to obtain a solution of a polymer having a guanamine bond and/or a ruthenium bond. The temperature at which the polymerization is carried out is, for example, between -20 ° C and 150 ° C, preferably between -5 ° C and 100 ° C. The polymerization time is usually from 5 minutes to 24 hours, preferably from 10 minutes to 8 hours.

The temperature at which the guanamine bond moiety is heated to dehydrate and cyclize to form a quinone bond is, for example, between 100 ° C and 350 ° C, preferably between 120 ° C and 320 ° C. The reaction time is, for example, from 3 minutes to 6 hours.

The relative proportions of the guanamine bond and the oxime imine bond in the polymer can be controlled by the following two methods. The first is to control the proportion of dehydration moles; the second is to dehydrate and cyclize a portion of the diamine benzene compound and the dianhydride compound in a specific ratio, and then add the remaining diamine at room temperature. The benzene compound and the dianhydride compound are polymerized.

When the diamine benzene compound of the first embodiment is polymerized with a tetracarboxylic acid or a dianhydride compound to produce a polymer having a guanamine bond and/or a ruthenium bond, other diamine compounds may be simultaneously added. The "other diamine compound" is not particularly limited, and may, for example, be an aromatic diamine compound, an aliphatic cyclic diamine compound or an aliphatic diamine compound.

The aromatic diamine compound is, for example, p-phenylenediamine, diamine diphenylmethane, diamine diphenyl ether, 2,2-diaminophenylpropane, bis(3,5-diethyl-4-amino group Phenyl)methane, diaminediphenylphosphonium, diaminobenzophenone, diaminonaphthalene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-amine Phenoxy)benzene, 4,4-bis(4-aminophenoxy)diphenylphosphonium, 2,2-bis(4,4-aminophenoxyphenyl)propane, 2,2- Bis(4-aminophenyl)hexafluoropropane and 2,2-bis(4,4-aminophenoxyphenyl)hexafluoropropane or the like.

The aliphatic cyclic diamine compound is, for example, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane or the like.

The aliphatic diamine compound is, for example, butanediamine or hexamethylenediamine.

The above other diamine compounds may be used singly or in combination of two or more.

In other words, in the polymer having a guanamine bond and/or a ruthenium bond, a repeating unit other than the repeating unit represented by any one of Formulas 6 to 9 may be further included. Wherein the repeating unit represented by any one of Formulas 6 to 9 accounts for 5 mole percent to 99 mole percent, preferably 30 mole percent to 99 mole percent, in the polymer. More preferably from 70 mole percent to 99 mole percent.

In the present embodiment, the content of the diamine benzene compound of the first embodiment is at least 1 mol%, preferably at least 10 mol%, more preferably at least 50, based on the total amount of the diamine compound used. Percent of moles.

In order to have a suitable molecular weight for a polymer having a guanamine bond and/or a ruthenium bond, tetracarboxylic acid The molar ratio of the acid or its dianhydride compound to the diamine benzene compound is, for example, between 0.8 and 1.2. When the molar ratio of the tetracarboxylic acid or its dianhydride compound to the diamine benzene compound is closer to 1, the molecular weight is larger and the viscosity is higher. When the molar ratio of the tetracarboxylic acid or its dianhydride compound to the diamine benzene compound is less than 1, an appropriate amount of end cap functional group may be added to reduce the terminal function caused by the molar ratio not equal to 1. The oxidation phenomenon of the base. Suitable terminal blocking functional groups are, for example, phthalic anhydride, maleic anhydride, aniline, cyclohexaneamine or the like.

After the polymerization reaction, the obtained polymer having a guanamine bond and/or a quinone bond has a degree of polymerization of, for example, 10 to 5,000, preferably 16 to 250, and a weight average molecular weight of, for example, 5,000 to 2,500,000, preferably It is 8,000 to 125,000.

In order to increase the degree of polymerization of the polymerization reaction and to reduce the reaction time, a catalyst may be added during the reaction. Suitable catalysts are, for example, triethylamine, diethylamine, n-butylamine, pyridine and the like. In addition to the function of increasing the degree of polymerization and reducing the reaction time, the catalyst also has a function of adjusting the pH of the solution.

The polymer having a guanamine bond and/or a quinone bond formed by the polymerization reaction is preferably between 10% by weight and 30% by weight based on the total weight of the solution.

A third embodiment of the present invention provides a composition for an alignment film comprising a polymer having a guanamine bond and/or a quinone bond in a second embodiment of the present invention, and a solvent.

In the present embodiment, the solvent in the composition for an alignment film may be an organic polar solvent such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamidine. Amine, N-methyl caprolactam, dimethyl hydrazine, γ-butyrolactone or the like.

Further, the composition for an alignment film may, for example, further comprise an organic oxime (oxy) alkane compound, an epoxy compound or the like as needed.

The organic oxime (oxy)alkyl compound is not particularly limited, and is, for example, aminopropyltrimethoxydecane, aminopropyltriethyldecane, vinylmethylnonane, N-(2-aminoethyl)- 3-aminopropyl Methyldimethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, vinyltriethoxydecane, 3-methylpropenyloxypropyltrimethyl Oxydecane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 2-(3,4-epoxycyclohexyl)ethyl Trimethoxydecane, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxycarbonyl 3-aminopropyltriethoxyamine decane, N-triethoxycarbenylpropyltriethylamine, N-trimethoxycarbamidopropyltriethylamine, N - bis(oxyethyl)-3-aminopropyltrimethoxydecane, N-bis(oxyethylidene)-3-aminopropyltriethyldecane or the like.

By appropriately controlling the content of the organic hydrazine (oxy) alkane compound in the composition for the alignment film, the adhesion of the liquid crystal alignment film to the surface of the substrate can be improved without affecting the demand characteristics of the liquid crystal alignment film. When the content of the organic hydrazine (oxy) alkane compound in the composition for an alignment film is too large, the formed liquid crystal alignment film is liable to cause poor alignment; if the content of the organic sulfonium compound in the composition for alignment film is too small The formed liquid crystal alignment film is liable to cause a phenomenon of poor brushing and excessive dusting. Therefore, in the present embodiment, the content of the organic oxime (oxy)ane compound is, for example, 0.01% by weight to 5% by weight, preferably 0.1% by weight, based on the total weight of the polymer contained in the composition for an alignment film. 3 weight percent.

The epoxy compound is not particularly limited, and it may be ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol condensed water. Glycerol ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N ',N'-tetraglycidyl-m-phenylene, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetrahydration Glyceryl-4,4'-diaminodiphenylmethane, 3-(N-allyl-N-glycidyl)aminopropyltrimethoxydecane, 3-(N,N-diglycidyl) Aminopropyltrimethoxydecane.

By appropriately controlling the content of the epoxy compound in the composition for the alignment film, When the required characteristics of the liquid crystal alignment film are affected, the adhesion of the liquid crystal alignment film to the surface of the substrate is further improved. When the content of the epoxy compound in the composition for an alignment film is too large, the formed liquid crystal alignment film is liable to cause poor alignment; and if the content of the epoxy compound in the composition for an alignment film is too small, the formed liquid crystal alignment film is easy. Poor brushing and excessive dusting. Therefore, in the present embodiment, the content of the epoxy compound is, for example, from 0.01% by weight to 3% by weight, based on the total weight of the composition for the alignment film, preferably from 0.1% by weight to 2% by weight.

In order to cooperate with the subsequent processing of the liquid crystal alignment film, the thickness and the coating property of the formed alignment film can be controlled by adjusting the viscosity and solid content of the composition for the alignment film. The method of adjusting the viscosity and the solid content is, for example, dilution with an organic solvent to a solid content of from 3 to 10% by weight. In the present embodiment, suitable organic solvents are, for example, N-methyl-2-pyrrolidone, m-cresol, γ-butyrolactone, N,N-dimethylacetamide, N,N-dimethyl Mercaptoamine or a mixture thereof. Alternatively, in the case where the solubility of the polymer having a guanamine bond and/or a ruthenium bond in a solvent is not caused, a polymer which cannot dissolve a polymer having a guanamine bond and/or a ruthenium bond may be added. Solvent. Such solvents are, for example, ethylene glycol monoethyl ether, ethylene glycol monobuthyl ether, diethylene glycol monobuthyl ether, diethyl Diethylene glycol monoethyl ether, butyl carbitol, ethyl carbitol acetate, ethylene glycol or a mixture thereof. The content of such a solvent is preferably controlled to be 90% by weight or less relative to the total weight of the solvent.

A fourth embodiment of the present invention provides an alignment film obtained by the composition for an alignment film according to the third embodiment.

The alignment film can be obtained by first dissolving a polymer having a guanamine bond and/or a quinone bond of the present invention in the above organic polar solvent, and then applying it to a glass substrate having a transparent electrode. Or on a transparent plastic film substrate. Then, at a temperature of 120 ° C to 350 ° C The solvent is evaporated by heat treatment to form a film. The alignment film of the present embodiment may be a liquid crystal alignment film which provides stable pretilt angle and high voltage retention of liquid crystal molecules.

A fifth embodiment of the present invention provides a liquid crystal display element including the alignment film in the fourth embodiment of the present invention.

The liquid crystal display element can be obtained by the following steps: First, a composition for an alignment film obtained from a polymer having a guanamine bond and/or a ruthenium bond is applied to a glass substrate by a coating method, followed by heating. Baking is performed to remove the organic solvent in the composition for the alignment film, and the uncircularized polyamic acid (repeating unit represented by Formula 6) is promoted to carry out a dehydration/ring-closing reaction to form an alignment film.

The coating method is, for example, a roll coating method, a spin coating method, or a printing coating method.

The glass substrate may have a patterned transparent conductive film.

The temperature of the heat baking is, for example, between 80 ° C and 300 ° C, preferably between 100 ° C and 240 ° C.

The thickness of the alignment film is preferably from 0.005 μm to 0.5 μm.

After forming the alignment film by heating and baking, for example, twisting nematic (TN) or vertical alignment (VA) can be performed by a roller wound with a nylon or cotton fiber cloth, so that the alignment film can provide liquid crystal. Molecular alignment.

Then, a sealant is coated on a substrate having the foregoing alignment film, and a spacer is sprayed on another substrate having the foregoing alignment film, and then the two alignment film substrates are combined with each other in a direction perpendicular to each other or parallel to each other. And liquid crystal is injected into the gap between the two substrates, and the injection hole is sealed, and the liquid crystal display element is initially formed. The process of subsequently completing the liquid crystal display element is well known to those of ordinary skill in the art and will not be described herein.

The voltage holding ratio can be used as an evaluation index of the liquid crystal display element. Voltage holding rate measurement conditions: DC at room temperature of 60 ° C (1V or 5V, 0.6Hz, pulse width 60 μsec) was applied to the liquid crystal display element, and the voltage holding ratio of the liquid crystal display element was measured.

<experiment>

Hereinafter, the present invention will be more specifically described by way of comparative examples and experimental examples, but the present invention is not limited to these experimental examples.

Synthesis Example (Synthesis of Diamine Benzene Compound)

First, 32.45 g of 1-phenylpiperazine was uniformly mixed in 170 g of tetrahydrofuran (THF), and 31.04 g of 1-fluoro-4-nitrobenzene was slowly added dropwise while stirring. (1-fluoro-4-nitrobenzene). The color of the solution gradually changed from light yellow to dark orange, and the mixture was stirred for 12 hours until a dark yellow precipitate was produced, and then THF was concentrated. The solid was poured into 510 g of isopropyl alcohol (IPA) for washing and filtration to obtain a dark yellow product, 1-(4-nitrophenyl)-4-phenylpiperazine (1-(4-nitrophenyl)). -4-phenylpiperazine), yield 83%. The 1H-NMR (d-DMSO) spectrum of the product is shown in Fig. 1, and the structure is shown below.

Next, 56.67 g of 1-(4-nitrophenyl)-4-phenylpiperazine was mixed with 304.01 g of THF, and 5.67 g of palladium-on-carbon (Pd/C) was added. ). Using a peristaltic pump, slowly instill 56.67 grams of 70% aqueous hydrazine hydrate. The color of the solution gradually changed from yellow to green, and after 12 hours of stirring, it was finally a white transparent liquid with a black suspension of Pd/C. The impurities were filtered through celite and concentrated to 200 g at 60 ° C, then the filtrate was poured into 1216 g of hexane to afford a white solid. After filtration, a white solid was obtained to give 4-(4-phenylpiperazin-l-yl)aniline as a white product (yield: 93%). The 1H-NMR (d-DMSO) spectrum of the product is shown in Fig. 2, and the structure is shown below.

Next, 49.75 g of 2-methyl-3,5-dinitrobenzoic acid was dissolved in 166.13 g of THF, and 45.39 g of N,N' were sequentially added. -N,N'-Dicyclohexylcarbodiimide (DCC), after producing a white suspension solid, then adding 45.39 g of THF and 50.67 g of 4-(4-phenylpiperazin-1-yl)aniline After the white suspended solid was gradually turned into an orange suspension solid, 55.38 g of THF was further added. After stirring for 12 hours and filtering the solid, an orange-yellow liquid product was obtained. The liquid was concentrated to 200 g at 60 ° C, poured into 1107.53 g of isopropanol solvent, and filtered to give the product as a yellow solid, 2-methyl-3,5-dinitro-N-(4-(4-phenyl) 2-methyl-3,5-dinitro-N-(4-(4-phenylpiperazin-1-yl)phenyl)benzamide), yield 74%. The 1H-NMR (d-DMSO) spectrum of the product is shown in Fig. 3, and the structure is shown below.

Finally, 92.29 g of 2-methyl-3,5-dinitro-N-(4-(4-phenylpiperazin-1-yl)phenyl)benzamide was mixed with 481.80 g of THF. And add 9.23 grams of Pd/C. Slowly drip 92.29 grams of 70% aqueous hydrazine using a peristaltic pump. The color of the solution gradually changed from yellow to green, and after 12 hours of stirring, it was finally a white transparent liquid with a black suspension of Pd/C. The impurities were filtered through celite and concentrated to 300 g at 60 ° C. Then, the filtrate was poured into 1927 g of isopropyl alcohol to obtain a white suspension solid. The white solid was collected by filtration to give 3,5-diamino-2-methyl-N-(4-(4-phenylpiperazin-1-yl)phenyl)benzamide (3,5-diamino 2-methyl-N-(4-(4-phenylpiperazin-1-yl)phenyl)benzamide) White product (monomer M1, that is, a compound represented by Formula 5), yield 87%. 1H-NMR (d-DMSO) spectrum of the product Figure 4 shows.

Experimental example 1

The diamine monomer M1 prepared in the 200 millimolar synthesis was dissolved in 150 ml of N-methylpyrrolidone (NMP), and 200 millimoles of 1,2,3,4-cyclobutane was added. Tetracarboxylic acid dianhydride (CBDA) was polymerized, and then N-methylpyrrolidone (NMP) was added to a solid content of 15% by weight. After 8 hours of reaction, a polyglycine solution having a solid content of 15% by weight was obtained. A1.

The polyamic acid solution A1 was diluted to a solid content of 6.5 weight percent with a mixed solvent of N-methylpyrrolidone (NMP) / diethylene glycol monobutyl ether (BC) (1:1 by weight). The alignment film composition was applied onto a glass substrate, and a film having a thickness of 1200 ± 100 Å was formed, heated to 230 ° C, and baked for 30 minutes to form an alignment film. Finally, a pair of substrates on which the alignment film is formed are taken, and combined with a liquid crystal (available from Merck, model number MJ012008) by a conventional method to obtain a liquid crystal layer containing a pair of alignment films sandwiched between the pair of alignment films and a The liquid crystal display elements D1 are respectively disposed on the electrode layers of the pair of alignment films away from the liquid crystal layer side.

Comparative example 1~3

200 mmol of M2 to M4 diamine compound (the structure of which is shown below) was dissolved in 150 ml of N-methylpyrrolidone (NMP), and 200 mM of 1,2,3,4 was added. - cyclobutane tetracarboxylic dianhydride (CBDA) was polymerized, and then N-methylpyrrolidone (NMP) was added to a solid content of 15% by weight. After 8 hours of reaction, a solid content of 15% by weight was obtained. Proline solutions A2, A3 and A4.

In the same manner as in Experimental Example 1, the polyaminic acid solutions A2 and A3 were respectively A4 is formed into an alignment film, and liquid crystal display elements D2, D3, and D4 on which the alignment film is formed are formed.

Experimental example 2~5

The diamine monomer M1 prepared by the synthesis example and para phenylene diamine (PPDA, CAS: 106-50-3) were dissolved in 200 ml of N-methylpyrrole at a specific ratio as shown in Table 1. In a ketone (NMP), a specific ratio of 1,2,3,4-butanetetracarboxylic dianhydride (1,2,3,4-Butanetetracarboxylic dianhydride, BT-100, CAS: 4534-73-0) was added. It was purchased from Qingtai) and polymerized at 25 ° C for 8 hours, followed by dehydration cyclization with toluene. After cooling, add 1,2,3,4-cyclobutane tetracarboxylic dianhydride (CBDA) in a specific ratio (see Table 1), and add N-methylpyrrolidone (NMP) to adjust the solid content to 15 The weight percentage was continuously stirred at 25 ° C for 8 hours to carry out polymer polymerization, and a polymer solution A5, A6, A7, and A8 containing a polyimine fragment and a poly-proline fragment having a solid content of 15% by weight was obtained. .

N-methylpyrrolidone (NMP) / diethylene glycol monobutyl ether (BC) (weight ratio The polymer solutions A5, A6, A7 and A8 prepared in Experimental Examples 2 to 5 were diluted to a solid content of 6.4% by weight in a 1:1) mixed solvent, and a liquid crystal group and an epoxy group were added in an amount of 0.1% by weight. The eucalyptus oil copolymer was obtained as a composition for an alignment film, and the composition for an alignment film was applied onto a glass substrate to form a film having a thickness of 1200 ± 100 Å, and heated to 230 ° C for 30 minutes to form an alignment film. Finally, a pair of substrates on which the alignment film is formed are combined with a liquid crystal (available from Merck, model number MJ012008) by a conventional method to obtain a liquid crystal layer and a pair of alignment films sandwiched between the pair of alignment films. The liquid crystal display elements D5, D6, D7, and D8 are disposed on the pair of electrode layers on the side of the liquid crystal layer, respectively.

The above "liquid crystal group and epoxy oxime copolymer" are reacted by the following three in a Pt catalysis of 0.01 g of PCT-PL-50T for 6 hours, and then heated to 120 ° C for 4 hours to obtain: (a) 25 grams of methyl hydrogen silicone oil 202 (UC202); (b) 12 g 4 '- (3-butenyl) -2' - fluoro-4-methyl-1,1 ': 4', 1 " - terphenyl (V2PGP1, purchased from Beijing Jinxun Sunshine Electronic Materials Technology Co., Ltd.); (c) 40 g of propylene glycidyl ether (AGE, CAS: 106-92-3).

At a temperature of 60 ° C, direct currents of 1 V and 5 V were applied to the obtained liquid crystal display elements D1 to D8, respectively, and voltage holding ratios in the liquid crystal display elements were measured, and the results are summarized in Table 2.

Comparing D1 and D2 to D4, it can be seen that the liquid crystal display element made of the diamine benzene compound M1 is compared with the liquid crystal display elements D2, D3 and D4 prepared from the diamine monomers M2, M3 and M4. D1 has a high voltage holding ratio (1V-VHR>80%; 5V-VHR>95%), which is advantageous for solving the afterimage problem of the liquid crystal display element.

Comparing D1, D2~D4 and D5~D8, it can be seen that even if a plurality of diamine monomers are used to form an alignment polymer, as long as the monomer M1 is mixed in the diamine monomers, the voltage holding ratio of the display element can be improved ( 1V-VHR>85%; 5V-VHR>95%), and whether the alignment polymer is pure poly-proline or a mixture of poly-proline and polyimine.

In summary, the present invention provides a diamine benzene compound, a polymer having a guanamine bond and/or a ruthenium bond bond prepared therefrom, a composition for an alignment film comprising the polymer, and the use of the alignment film An alignment film and a liquid crystal display element made of the composition. The diamine benzene compound has a high polarization parameter, and therefore, the liquid crystal display element has an excellent voltage holding ratio, and can effectively solve the afterimage problem of the liquid crystal display element.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

Claims (10)

A diamine benzene compound, as shown in Formula 1: H ₂ N-Ar-NH ₂ Formula 1, wherein Ar is a residue of the diamine benzene compound, as shown in Formula 2: Wherein * is a position in which the group represented by Formula 2 and the two -NH ₂ groups of Formula 1 are bonded; R _{1 is} each independently, and is a hydrogen atom or a monovalent substituent other than the primary amine group; X ₁ is included or a divalent linking group; R ₂ is a divalent linking group including a benzene ring or a cyclohexane ring, wherein the benzene ring or the hydrogen of the cyclohexane ring may independently pass through a C ₁ -C ₃ alkyl group , F, Cl, -OH or -CN substituted; X ₂ and X ₃ are each a C ₁ -C ₃ linear alkylene group; and R ₃ is a monovalent substituent including a benzene ring or a cyclohexane ring, wherein The hydrogen of the benzene ring or the cyclohexane may be independently substituted with C ₁ -C ₃ alkyl, F, Cl, -OH or -CN. The diaminobenzene compound according to claim 1, wherein R ₂ is an aromatic group. The diaminobenzene compound according to claim 1, wherein R ₂ is a group represented by Formula 3: Wherein Q ₁ to Q ₄ are each a hydrogen atom or a C ₁ -C ₃ alkyl group. The diaminobenzene compound according to claim 1, wherein R ₃ is a group represented by formula 4: Wherein Q ₅ to Q ₉ are each a hydrogen atom or a C ₁ -C ₃ alkyl group. The diaminobenzene compound according to claim 1, which is represented by Formula 5: A polymer having a guanamine bond, a quinone bond or a combination of the foregoing, comprising a unit represented by any one of Formulas 6 to 9: Wherein G ₁ is a C ₂ -C ₃₀ aliphatic tetracarboxylic acid residue, an alicyclic tetracarboxylic acid residue or an aromatic tetracarboxylic acid residue, and G ₂ is a C ₂ -C ₃₀ aliphatic tricarboxylic acid residue a alicyclic or alicyclic residue or an aromatic tricarboxylic acid residue, and G ₃ is a C ₂ - C ₃₀ aliphatic dicarboxylic acid residue, an alicyclic dicarboxylic acid residue or an aromatic dicarboxylic acid. The residue, R _{4 ,} each independently, is a hydrogen atom or a C ₁ -C ₂₀ alkyl group, and Ar in the formula 6 to formula 9 is the diamine according to any one of claims 1 to 5. The residue of the benzene compound. A polymer having a guanamine bond, a ruthenium bond or a combination of the two, as described in claim 6, wherein the unit represented by any one of Formulas 6 to 9 is in the polymer. The proportion is from 5 mole percent to 99 mole percent. A composition for an alignment film comprising a polymer having a guanamine bond, a quinone bond or a combination of the two, as described in claim 6 or 7. An alignment film obtained by using the composition for an alignment film according to item 8 of the patent application. A liquid crystal display element comprising the alignment film according to claim 9 of the patent application.