TWI483921B - Diamine compound, liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display device having thereof - Google Patents

Description

Diamine compound, liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element thereof

The present invention relates to a liquid crystal alignment film and a liquid crystal display element produced by a diamine compound, a liquid crystal alignment agent and a liquid crystal alignment agent.

In order to improve the image quality of the liquid crystal display element, the liquid crystal alignment film should have the following properties: (1) good electrical characteristics: low image sticking effect (Image Sticking Effect), high voltage holding ratio, and the like. (2) Good alignment ability: The more uniform the pretilt angle of the liquid crystal molecules, the smaller the difference in steering after the liquid crystal molecules are driven by the electric field, and the image quality of the liquid crystal display element is better.

However, poly-proline (PAA) or polyimine (PI) alignment films with pretilt angle requirements are currently available, mostly using a diamine with a linear long carbon chain as a synthetic reactant, but the aforementioned PAA, The PI alignment film, under the severe weathering operation under high temperature and high humidity, still produces a liquid crystal reversal line which is low in pretilt angle near the edge of the sealant or poorly aligned in the middle of the filler.

With the popularization of liquid crystal display elements, consumers are increasingly demanding the imaging quality of liquid crystal display elements. How to improve the liquid crystal display elements so that they are not easily affected by the use environment such as temperature and humidity, and can have excellent and stable image quality. It is the goal of the relevant industry.

An object of the present invention is to provide a diamine compound which can be used for preparing a liquid crystal alignment agent which can further form a liquid crystal alignment film and a liquid crystal display element, whereby the liquid crystal display element has a comparative The low image sticking problem and the relatively stable alignment ability, when used in high temperature or high humidity environment, will not affect the alignment ability, and thus provide excellent and stable image quality.

One embodiment according to an aspect of the present invention provides a diamine compound having the structure shown in formula (I): Wherein X is -O- or -COO-, and the L and Z systems are each independently a cyclohexane group, a phenyl group or a single bond, and the L and the Z are not simultaneously a single bond, and M is a carbon number of 1 to 10 The alkyl group or an alicyclic group having a carbon number of 4 to 30.

According to the aforementioned diamine compound, wherein X may be -O- or -COO-, L and Z may each independently be a cyclohexane group or a single bond, and the L and the Z are different. When it is a single bond, M may be an alkyl group having 1 to 10 carbon atoms or an alicyclic group having 4 to 30 carbon atoms.

Another embodiment in accordance with an aspect of the present invention provides a liquid crystal alignment agent comprising a polymer which is formed by a polymerization reaction of any of the foregoing diamine compounds.

According to the aforementioned liquid crystal alignment agent, the polymer may be a polyamic acid, a polyimine or a quinone imine-proline copolymer. The reactant of the polymerization reaction may further comprise other diamine compounds and tetracarboxylic dianhydride. The tetracarboxylic dianhydride may contain an aromatic tetracarboxylic dianhydride of 30 mole percent or more. More preferably, the tetracarboxylic dianhydride may comprise from 50 mole percent to 80 mole percent of the aromatic tetracarboxylic dianhydride. When the reactant of the polymerization reaction comprises a diamine compound of the formula (I) and another diamine compound, the diamine compound of the formula (I) may constitute a diamine compound of the formula (I) and other diamines. A total of 3 mole percent of the total content of the compound to 20 mole percent.

According to still another embodiment of the present invention, there is provided a liquid crystal alignment film formed of the liquid crystal alignment agent of any of the above.

Still another embodiment in accordance with an aspect of the present invention provides a liquid crystal display element comprising the liquid crystal alignment film described above.

Diamine compound

a diamine compound having the structure shown in formula (I): Wherein X is -O- or -COO-, and the L and Z systems are each independently a cyclohexane group, a phenyl group or a single bond, and the L and the Z are not simultaneously a single bond, and M is a carbon number of 1 to 10 The alkyl group or an alicyclic group having a carbon number of 4 to 30.

The above-mentioned diamine compound, wherein X may be -O- or -COO-, L and Z may each independently be a cyclohexane group or a single bond, and the L and the Z are not simultaneously a single bond, and M may be a carbon number It is an alkyl group of 1 to 10 or an alicyclic group having a carbon number of 4 to 30.

When X of the diamine compound is -COO-, L and Z are each independently a cyclohexane group, and M is a pentyl group, and the structure thereof is as shown in the formula (a-1-1):

When X of the diamine compound is -O-, L and Z are each independently a cyclohexane group, and M is a pentylene group, and the structure thereof is as shown in the formula (a-1-2): (a-1-2).

When X of the diamine compound is -COO-, L and Z are each independently a single bond, and M is an alicyclic group having a carbon number of 27, and its structure is as shown in the formula (a-1-3): The above diamine compound can be used as a reactant of a liquid crystal alignment agent. When it is used as a reactant of a liquid crystal alignment agent, the above diamine compound can be used singly or in combination.

Other diamine compounds

The "other diamine compound" means a diamine compound other than the diamine compound of the formula (I). Other diamine compounds may be, but are not limited to, the structures shown by formula (a-2-1), formula (a-2-2), (a-2-3) or formula (a-2-4): (a-2-3), (a-2-4). The above other diamine compound can be used as a reactant of a liquid crystal alignment agent. When it is used as a reactant of a liquid crystal alignment agent, the above other diamine compounds may be used singly or in combination.

Tetracarboxylic dianhydride

The tetracarboxylic dianhydride may be, but not limited to, the structure represented by the formula (a-3-1), the formula (a-3-2) or the formula (a-3-3): The tetracarboxylic dianhydride may be used as a reactant of a liquid crystal alignment agent. When it is used as a reactant of a liquid crystal alignment agent, the tetracarboxylic dianhydride may be used singly or in combination.

Polymer (A)

The polymer (A) is formed by a polymerization reaction of a diamine compound of the formula (I), the polymer (A) can be used for preparing a liquid crystal alignment agent, and the polymer (A) can be a polyamic acid or a polyimine. Or a quinone imine-proline copolymer.

The reactant of the foregoing polymerization reaction may further comprise other diamine compounds and tetracarboxylic dianhydride. When the polymer of the polymer (A) is reacted, the reactants are the same When the diamine compound of the formula (I), the other diamine compound and the tetracarboxylic dianhydride are contained, the diamine compound of the formula (I) accounts for 3 mole percent to 20 mole percent of the total content of all the diamine compounds, "All diamine compounds" means a general term for a diamine compound of the formula (I) and other diamine compounds. The tetracarboxylic dianhydride may use two or more kinds of tetracarboxylic dianhydrides at the same time, and the tetracarboxylic dianhydride may simultaneously use an alicyclic tetracarboxylic dianhydride and an aromatic tetracarboxylic dianhydride. When the tetracarboxylic dianhydride uses both the alicyclic tetracarboxylic dianhydride and the aromatic tetracarboxylic dianhydride, the aromatic tetracarboxylic dianhydride content in the tetracarboxylic dianhydride is 30 mol% or more, more preferably The aromatic tetracarboxylic dianhydride content of the tetracarboxylic dianhydride is from 50 mole percent to 80 mole percent.

Method for synthesizing polymer (A)

Hereinafter, the polymer (A) is a ruthenium-proline copolymer, and the synthesis method of the polymer (A) will be described in detail.

The polymer (A) is polymerized in an organic solvent with a diamine compound of the formula (I), another diamine compound, and a tetracarboxylic dianhydride as a reactant, and is carried out at a temperature of 40 ° C to 110 ° C for 1 to 12 hours. In order to obtain a reaction solution containing polyamic acid, the temperature and time of the above polymerization reaction can be elastically adjusted according to the amount of the reactants.

The ratio of the diamine compound of the formula (I) to the other diamine compound and the tetracarboxylic dianhydride is such that the anhydride group content of the tetracarboxylic dianhydride is 1 equivalent, and the amine group of all the diamine compounds is 0.5 to 2 equivalents. Good, 0.7 to 1.5 equivalents is better.

The organic solvent is used to dissolve the reactants and products, and according to the solubility of the organic solvent to the reactants and products, it can be distinguished that the solubility is better. Machine solvent and organic solvent with poor solubility.

Preferred organic solvents include, but are not limited to, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl caprolactam, dimethyl hydrazine, tetramethyl urea, hexamethylphosphonium, γ-butyrolactone or pyridine, the above organic solvent can be It can be used alone or in combination of two or more.

The organic solvent having a poor solubility may also be used in combination with the above-mentioned organic solvent having a better solubility, provided that the product quinone imine-proline copolymer is not precipitated. Poorly soluble organic solvents include, but are not limited to, methanol, ethanol, isopropanol, n-butanol, cyclohexanol, ethylene glycol, ethylene glycol methyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl Ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethyl ether, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, tetrahydrofuran, dichloromethane, Trichloromethane, 1,2-dichloroethane, benzene, toluene, xylene, n-hexane, n-heptane or n-octane.

In addition to the above-exemplified organic solvents, an organic solvent which can dissolve the quinone imine-proline copolymer can be used as the organic solvent for the polymerization reaction of the present invention.

The above reaction solution containing polylysine is subjected to partial dehydration ring-closure reaction to obtain a reaction solution containing a quinone imine-proline copolymer.

The dehydration ring closure reaction can be carried out by the method (1): direct heating, or the method (2): adding a dehydrating agent and a catalyst.

Method (1): direct heating, the reaction temperature is about 50 ° C ~ 300 ° C, and preferably 100 ° C ~ 250 ° C. When the reaction temperature is lower than 50 ° C, the dehydration closed loop The reaction does not proceed, and if the reaction temperature is too high, the average molecular weight of the resulting polymer (A) will be very low.

Method (2): adding a dehydrating agent and a catalyst, the reaction temperature is about -20 ° C to 150 ° C, and preferably 0 ° C to 120 ° C.

The dehydrating agent includes, but is not limited to, an acid anhydride, and an acid anhydride such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride or the like can be used. The amount of the dehydrating agent is adjusted depending on the desired dehydration ring closure ratio, and it is preferably 0.01 to 20 mol per 1 unit of the molybdenum imine-proline copolymer.

The catalyst includes, but is not limited to, a tertiary amine such as triethylamine, pyridine, lutidine, and the like. The amount of the catalyst is adjusted depending on the amount of the dehydrating agent, and about 0.01 to 10 moles of the catalyst is used per 1 mole of the dehydrating agent.

Finally, the above reaction solution containing a ruthenium-proline copolymer is poured into a solvent having a poor solubility to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a quinone imine-oxime. Amino acid copolymer. The obtained quinone imine-proline copolymer can be purified one or more times, and the purification step is as follows: the quinone imine-proline copolymer is dissolved in an organic solvent and precipitated with a solvent having poor solubility, and The precipitate was dried under reduced pressure.

When the polymer (A) is a poly-proline, the preparation method is substantially the same as the above reaction, and only the dehydration ring-closure reaction needs to be skipped. When the polymer (A) is a polyimine, the reaction solution containing the poly-proline may be subjected to a complete dehydration ring-closure reaction.

Liquid crystal alignment agent

The liquid crystal alignment agent of the present invention comprises a polymer (A) and an organic solvent. And optionally, an additive is included.

The above polymer (A) is dissolved in an organic solvent to form a liquid crystal alignment agent. The temperature at which the liquid crystal alignment agent is prepared is preferably from 0 ° C to 150 ° C, more preferably from 20 ° C to 50 ° C.

The liquid crystal alignment agent can adjust the solid content contained therein according to the viscosity and the volatility, and preferably contains a solid content of 1% by weight to 10% by weight. If the solid content is less than 1% by weight, the thickness of the liquid crystal alignment film after coating is too thin to lower the alignment ability, and if the solid content is more than 10% by weight, the coating quality is affected.

The aforementioned organic solvent for dissolving the polymer (A) includes, but is not limited to, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N,N-dimethyl Formamide, N,N-dimethylacetamide, N-methyl caprolactam, dimethyl hydrazine, γ-butyrolactone, γ-butyrolactam, ethylene glycol monomethyl ether Ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether or ethylene glycol monobutyl ether. The above solvents may be used in combination of two or more. In addition to the solvents listed above, any soluble imipenem-proline copolymer is suitable.

The liquid crystal alignment agent may optionally contain an additive, and the additive may be an organic oxime (oxy) alkane compound or an epoxy compound. It is conventional to use an organic oxime compound and an epoxy compound as a liquid crystal alignment agent. I will not repeat them here.

Liquid crystal alignment film

The method for forming a liquid crystal alignment film comprises the steps of: first, applying a liquid crystal alignment agent of the present invention onto a glass substrate having a patterned transparent conductive film to form a coating layer, including but not limited to a roll coating method, The spin coating method and the printing method are conventional, and will not be described herein.

Next, the coating layer is baked by heating to form a coating layer of the liquid crystal alignment film. The purpose of the heat baking is to remove the organic solvent in the liquid crystal alignment agent, and to promote the dehydration ring closure reaction of the polyamic acid contained in the polymer (A). The heating and baking temperature may be 80 ° C to 300 ° C, more preferably 100 ° C to 240 ° C. The thickness of the liquid crystal alignment film formed is preferably 0.005 to 0.5 μm.

Finally, the directional friction is performed by a roller wound with a nylon or cotton fiber cloth, so that the liquid crystal alignment film has an alignment ability to the liquid crystal molecules.

Liquid crystal display element

The method of forming a liquid crystal display element comprises the steps of: first applying a sealant on a glass substrate having the liquid crystal alignment film, and spraying a spacer on another glass substrate having the liquid crystal alignment film.

Next, the two glass substrates having the liquid crystal alignment film described above are combined in such a manner that the brush directions of the films are perpendicular to each other or parallel to each other.

Finally, liquid crystal is injected into the gap between the two glass substrates, and the injection holes are sealed to form a liquid crystal display element.

Evaluation method of liquid crystal display element

(1) Pretilt angle variability: The liquid crystal display element that has been injected into the liquid crystal (ZLI-4792) is measured by the crystallization rotation method (the measurement machine is Autronic TBA-107), and the pretilt angle variation is calculated according to the measurement result. degree. Specifically, firstly, the pretilt angle of nine points in the plane of the liquid crystal display element is measured and the average value K1 is obtained, and the pretilt angle of nine points on the edge of the liquid crystal display element is measured and the average value K2 is obtained, and the absolute difference between K1 and K2 is obtained. Value as pretilt angle The variability, the smaller the pretilt variability, the higher the stability of the pretilt angle. The “in-plane” refers to the distance from the frame glue to more than 0.51 cm, and the “edge” refers to the distance from the frame glue of less than 0.5 cm.

(II) Judgment of image sticking phenomenon: The liquid crystal display element which has been injected into the liquid crystal (ZLI-4792) is used as a basis for determining the residual image phenomenon by measuring the brightness value before and after charging and calculating the percentage change of brightness. Specifically, the transmittance and the voltage change curve of the specific position of the liquid crystal display element are first measured under the pass voltage, and the voltage value V1 when the transmittance is 50% is obtained, and the liquid crystal display element is driven by the voltage value V1 for 10 minutes and then recorded. After the brightness value K3, the liquid crystal display element is charged with the alternating current of 10 volts for 30 minutes, the liquid crystal display element is driven again by the voltage value V1 for 10 minutes, and the brightness value K4 is recorded. The calculation formula of the brightness change percentage is: (| K3-K4 |/K3)×100%, if the percentage change of brightness is less than 0.5%, the residual image phenomenon is judged to be excellent, 0.5%~1% is judged to be the residual image phenomenon, and more than 1% is judged to be the residual image phenomenon.

(3) Determination of high temperature and high humidity defects: liquid crystal display elements that have been injected into liquid crystal (ZLI-4792) are placed at a temperature of 121 ° C, humidity of 100% and 2 atmospheres for 24 hours, using Polarizing Optical Microscopy (POM). Observe the occurrence of defects caused by liquid crystal inversion in the in-plane and edge of the liquid crystal display element at 50 times, and count the number of defects. When the number of defects is less than 10 and the in-plane defect-free determination is superior, when the number of defects is greater than 10 and in-plane The defect-free determination is medium, and when the number of defects is greater than 10 and the in-plane defect is judged to be poor.

(4) Dehydration ring closure ratio (imidization ratio): the polymer (A) or the liquid crystal alignment agent is dried under reduced pressure at room temperature, and the dried solid is continuously dried. Dissolved in deuterated dimethyl hydrazine, using tetramethyl decane as a reference material, calculated by 1H-NMR, calculated by imitation ratio: imidization ratio (%) = (1-K5/ (K6 × α)) × 100%, wherein K5 is the peak area derived from protons of the NH group (10 ppm), K6 is the peak area derived from other protons, and α is the proton of other protons relative to the polymer (A) The ratio of the number of protons of the NH group of the substance (polyglycolic acid).

Synthesis of diamine compounds <Synthesis Example 1>: Synthesis of a diamine compound of the formula (a-1-1)

The reaction equation 1 for the synthesis of the diamine compound of the formula (a-1-1) is as follows:

(a) Synthesis of the compound of formula (i): In a 2-liter reaction flask, add 4-gram of 4-nitrobenzoyl chloride 102 g (550 mmol), toluene (1200 g) and Potassium carbonate (75.9 g (550 mmol) was stirred at room temperature for 5 minutes. Further, 126 g (500 mmol) of 4-(4'-n-pentyl)-dicyclohexanol (400 mg) was dissolved in 200 g of toluene and slowly dropped into the aforementioned reaction bottle. in. After all the dropwise additions were completed, the mixture was further stirred at room temperature for 4 hours. After extracting 3 times with pure water, the organic layer was dried over magnesium sulfate, and the filtrate was collected by filtration and concentrated under reduced pressure to give the product 188.5 g (470 mmol), yield 94%.

Spectral data of the above products: ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.30~8.23 (2H), 8.15~8.20 (2H), 5.24~5.36 (0.6H), 4.85~4.95 (0.4H) and 0.8~2.1 (30H) ppm. From the spectral data, it is known that the structure of the above product is that formula (i) is correct.

(b) Synthesis of the compound of formula (ii): In a 2 liter reaction flask, 188.5 g (470 mmol) of the compound of formula (i), 1000 g of toluene and 10% palladium-on catalyst (10% Palladium-on) were added. -carbon) 10 g, stir for 10 minutes. Further, 50 ml of 80% aqueous hydrate (80% Hydrazine hydrate) was slowly added dropwise, and the mixture was stirred for 4 hours. The reaction temperature was lowered to room temperature, filtered off with suction, and the filtrate was taken, and the solvent was concentrated under reduced pressure to give the product 174 g (470 mmol).

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 7.80~7.86 (2H), 6.58~6.65 (2H), 5.15~5.20 (0.6H), 4.75~4.85 (0.4H), 3.96~4.06 ( 2H) and 0.8~2.1 (30H) ppm. From the spectral data, the structure of the above product is formula (ii).

(3) Synthesis of compound of formula (iii): In a 2-liter reaction flask, 3,5-Dinitrobenzoyl chloride (115.3 g (500 mmol)), toluene 500 g With potassium carbonate 103.7 g (750 Milligrams, stirred at room temperature for 5 minutes, and another 170 g of the compound of the formula (ii) (460 mmol) was dissolved in 500 g of toluene and slowly dropped into the aforementioned reaction flask. After all the dropwise additions were completed, the mixture was further stirred at room temperature for 4 hours. The mixture was extracted with pure water for 3 times, and the organic layer was dried over magnesium sulfate. The filtrate was collected by filtration and concentrated to dryness under reduced pressure to give 221 g (390 mmol).

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 9.19~9.22 (1H), 9.08~9.11 (2H), 8.40~8.42 (1H), 8.05~8.11(2H), 7.74~7.79(2H) 5.11~5.27(0.6H), 4.81~4.90(0.4H) and 0.8~2.1(30H)ppm. From the spectral data, the structure of the above product is (iii).

(4) Synthesis of compound of formula (a-1-1): In a 2-liter reaction flask, 221 g (390 mmol) of compound of formula (iii), 1400 g of tetrahydrofuran (Tetrahydrofuran) and 10% palladium carbon are added. 11 g of catalyst was stirred for 10 minutes. Then, 100 ml of 80% aqueous hydrazine was slowly added dropwise, and the mixture was stirred for 4 hours. The reaction temperature was lowered to room temperature, filtered with suction, and the filtrate was taken, and the solvent was concentrated under reduced pressure to give the product 197 g (390 m.m.).

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 7.98~8.05 (2H), 7.84~7.89 (1H), 7.64~7.70 (2H), 6.51~6.54(2H), 6.12~6.16(1H) 5.19~5.23 (0.6H), 4.81~4.90 (0.4H) and 0.8~2.1(30H)ppm. From the spectral data, the structure of the above product is the formula (a-1-1).

<Synthesis Example 2>: Synthesis of a diamine compound of the formula (a-1-2)

The reaction equation 2 for the synthesis of the diamine compound of the formula (a-1-2) is as follows:

(a) Synthesis of compound of formula (iv): In a 2-liter reaction flask, add 77.6 g (550 mmol) of 4-fluoronitrobenzene, 1200 g of toluene and sodium hydroxide (Sodium hydroxide) 22 g (550 mmol), stirred at room temperature for 5 minutes, and further dissolved 126 g (500 mmol) of 4-(4'-n-pentyl)-dicyclohexanol in 200 g of toluene. Slowly drip into the aforementioned reaction flask. After all the dropwise additions were completed, the mixture was further stirred at room temperature for 4 hours. The mixture was extracted with pure water for 3 times, and the organic layer was dried over magnesium sulfate. The filtrate was collected by filtration and concentrated to dryness to give 168 g (450 m.

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 8.30~8.23(2H), 8.15~8.20(2H), 5.24~5.36(0.6H), 4.85~4.95(0.4H) and 0.8~2.1( 30H) ppm. From the spectral data, the structure of the above product is that formula (iv) is correct.

(b) Synthesis of compound of formula (v): In a 2 liter reaction flask, 149 g (400 mmol) of compound of formula (iv), 1000 g of toluene and 7.5 g of 10% palladium carbon catalyst were added and stirred for 10 minutes. . Further, 45 ml of 80% aqueous hydrazine was slowly added dropwise, and the mixture was stirred for 4 hours. The reaction temperature was lowered to room temperature, suction filtered, and the filtrate was taken. The solvent was concentrated under reduced pressure to give 137 g (400 m.m.).

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 7.80~7.86 (2H), 6.58~6.65 (2H), 5.15~5.20 (0.6H), 4.75~4.85 (0.4H), 3.96~4.06 ( 2H) and 0.8~2.1 (30H) ppm. From the spectral data, the structure of the above product is formula (v).

(3) Synthesis of compound of formula (vi): In a 2-liter reaction flask, add 35.3-dinitrobenzidine chloride 115.3 g (500 mmol), toluene 500 g and potassium carbonate 103.7 g (750 m) The mixture was stirred at room temperature for 5 minutes, and another 137 g of the compound of the formula (v) (400 mmol) was dissolved in 500 g of toluene, and slowly dropped into the aforementioned reaction flask. After all the dropwise additions were completed, the mixture was further stirred at room temperature for 4 hours. After extracting 3 times with pure water, the organic layer was dried over magnesium sulfate, and the filtrate was collected by filtration and concentrated under reduced pressure to give 178 g (340 m.

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 9.19~9.22 (1H), 9.08~9.11 (2H), 8.40~8.42 (1H), 8.05~8.11(2H), 7.74~7.79(2H) 5.11~5.27(0.6H), 4.81~4.90(0.4H) and 0.8~2.1(30H)ppm. From the spectral data, the structure of the above product is (vi).

(4) Synthesis of compound of formula (a-1-2): In a 2 liter reaction flask, 172 g (330 mmol) of compound of formula (vi), 1400 g of tetrahydrofuran and 9 g of 10% palladium carbon catalyst are added. Stir for 10 minutes. Further, 90 ml of 80% aqueous hydrazine was slowly added dropwise, and the mixture was stirred for 4 hours. The reaction temperature was lowered to room temperature, filtered with suction, and the filtrate was taken, and the solvent was concentrated under reduced pressure to give the product 152 g (330 m.m.).

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 7.98~8.05 (2H), 7.84~7.89 (1H), 7.64~7.70 (2H), 6.51~6.54(2H), 6.12~6.16(1H) 5.19~5.23 (0.6H), 4.81~4.90 (0.4H) and 0.8~2.1(30H)ppm. From the spectral data, the structure of the above product is the formula (a-1-2).

<Synthesis Example 3>: Synthesis of a diamine compound of the formula (a-1-3)

The reaction equation 3 for the synthesis of the diamine compound of the formula (a-1-3) is as follows:

(a) Synthesis of the compound of formula (vii): In a 2 liter reaction flask, 50 g (130 mmol) of dimethodol, 300 g of dichloromethane and pyridine (pyridine) were added. ) 10.3 g (130 mmol), stirred at room temperature for 20 minutes, and another 30 g of 4-nitrobenzhydryl chloride (160 mmol) dissolved in 150 g of dichloromethane, and slowly dropped into the foregoing In the reaction bottle. After all the dropwise drops, heat to 50 ° C ~ 60 ° C, and stir for another 4 hours. Thereafter, the mixture was extracted three times with saturated aqueous sodium hydrogen sulfate, and the organic layer was dried over magnesium sulfate, and the filtrate was collected by filtration, and concentrated to dryness under reduced pressure to give the product 62.9 g.

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 8.2~8.25(2H), 8.12~8.30(2H), 4.90~5.03(1H) and 0.6~2.02(46H)ppm. The structure of the aforementioned product is the formula (vii).

(b) Synthesis of compound of formula (viii): In a 2 liter reaction flask, 50 g (93 mmol) of compound of formula (vii), 300 g of tetrahydrofuran and 2.5 g of 5% palladium carbon catalyst were added and stirred for 20 minutes. . Further, 14 ml of 80% aqueous hydrazine was slowly added dropwise, and the mixture was stirred for 4 hours. The reaction temperature was lowered to room temperature, suction filtered, and the filtrate was concentrated. The solvent was concentrated under reduced pressure to give the product 47.2 g, yield 100%.

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 7.82~7.88 (2H), 6.60~6.68(2H), 4.80~4.96(1H), 4.01~4.05(2H) and 0.6~2.02(46H) Ppm. From the spectral data, it is known that the structure of the above product is the formula (viii).

(3) Synthesis of compound of formula (ix): In a 2 liter reaction flask, 40 g (80 mmol) of compound of formula (viii), 200 g of dichloromethane and 6.5 g of pyridine (80 mmol) are added. After stirring at room temperature for 20 minutes, another 24 g of 3,5-dinitrobenzidine chloride (104 mmol) was dissolved in 150 g of dichloromethane, and slowly dropped into the aforementioned reaction flask. After all the dropwise drops, heat to 50 ° C ~ 60 ° C, and stir for another 4 hours. After that, it was extracted three times with saturated aqueous sodium hydrogencarbonate, and the organic layer was dried over magnesium sulfate. The filtrate was collected by filtration and concentrated to dryness under reduced pressure to give 50.5 g of the product.

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 9.20~9.24 (1H), 9.10~9.15(2H), 8.58~8.61(1H), 8.08~8.13(2H), 7.78~7.83(2H) 4.80~4.96(1H) and 0.6~2.02(46H)ppm. From the spectral data, the structure of the above product is (ix).

(4) Synthesis of compound of formula (a-1-3): In a 2 liter reaction flask, 50 g (93 mmol) of compound of formula (ix), 300 g of tetrahydrofuran, 5% palladium carbon catalyst 2.5 g were added. Stir for 20 minutes. Further, 14 ml of 80% aqueous hydrazine was slowly added dropwise, and the mixture was stirred for 4 hours. The reaction temperature was lowered to room temperature, filtered with suction, and the filtrate was taken, and the solvent was concentrated under reduced pressure to give the product 59.7 g, yield 100%.

Spectral data of the above products: ¹ H NMR (400MHz, CDCl ₃ ) δ is 8.01~8.06(2H), 7.84~7.90(1H), 7.64~7.70(2H), 6.51~6.55(2H), 6.14~6.18(1H) 4.88~5.01(1H), 3.70~3.80(4H) and 0.6~2.04(46H)ppm. From the spectral data, the structure of the above product is the formula (a-1-3).

Synthesis of polymer (A) and other polymers

The polymer (A) is produced by a polymerization reaction of a diamine compound of the formula (I), and the following polymers A1 to A6 all belong to the polymer (A). The other polymer means that the reactant does not contain the diamine compound of the formula (I), and the polymers a1 to a3 and the polymers B1 to B2 are all other polymers. The diamine compound, other diamine compound and tetracarboxylic dianhydride were polymerized in N-methyl-2-pyrrolidone according to the ratio shown in Table 1, wherein the polymers A1, A2, a1, a2, B1 were polymerized. B2 has a dehydration ring-closing reaction, which is a ruthenium-proline copolymer, and the polymers A3~A6 and a3 are not subjected to a dehydration ring closure reaction, and are poly-proline.

Liquid crystal display elements of Examples 1 to 9 and Comparative Examples 1' to 5'

The polymers A1~A5, a1~a3 and B1~B2 were dissolved in a mixed solvent of γ-butyrolactone and N-methyl-2-pyrrolidone according to the ratio shown in Table 2 to prepare a solid content of 6 wt%. The solution was filtered through a filter having a diameter of 1 μm, and the collected filtrates were the liquid crystal alignment agents used in Examples 1 to 9 and Comparative Examples 1' to 5'.

The liquid crystal alignment agent obtained above was applied onto a glass substrate by a roller printer, and dried on a hot plate at 220 ° C for 20 minutes to form a film having a thickness of 0.08 μm. The film was oriented at a roller speed of 1000 rpm, a platform moving speed of 60 mm/sec, and a press-in amount of 0.4 μm.

The frame filler is coated on the glass substrate having the liquid crystal alignment film, and the spacer is sprayed on the glass substrate of the other liquid crystal alignment film, and the two glass substrates having the liquid crystal alignment film are mutually perpendicular to each other. The liquid crystal display element is formed by injecting liquid crystal (ZLI-4792) into the gap between the two glass substrates and sealing the injection hole.

The obtained liquid crystal display element was evaluated for pretilt angle variability, image sticking phenomenon determination, high temperature and high humidity defect determination, and the evaluation results are shown in Table 2.

As can be seen from Table 2, the liquid crystal alignment agents used in Examples 1 to 9 all contained the polymer (A) produced by using the diamine compound of the formula (I) as a reactant, and used in Comparative Examples 1' to 5'. The liquid crystal alignment agent contains only other polymers and does not contain the polymer (A).

From the evaluation results of the pretilt angle variability, the pretilt angle variability of Examples 1 to 9 is 0.1 to 0.5, and the pretilt angle variability of the comparative example 1' to 5' is 1.0 to 1.3, which is much higher than the embodiment, that is, The difference in pretilt angle between the in-plane and the edge of the liquid crystal display element of the present invention is extremely small, and it is shown that the liquid crystal display element of the present invention can provide stable alignment ability.

It can be seen from the judgment results of the residual image phenomenon that the determination results of the residual image phenomenon of Examples 1 to 9 are excellent, and the determination results of the residual image phenomenon of the comparative examples 1' to 5' are both moderately far less than that of the embodiment 1~ 9, that is, the liquid crystal display element of the present invention has a low afterimage phenomenon and can provide good image quality.

It can be seen from the determination results of high temperature and high humidity defects that the determination results of the high temperature and high humidity defects of Examples 1 to 9 are excellent, and the results of the high temperature and high humidity defects of the comparative examples 1' to 5' are moderate or poor and far lower than the examples. That is, the liquid crystal display element of the present invention is not easily affected by the high temperature and high humidity of the external environment, and has a long service life and can provide stable image quality.

In summary, the present invention prepares a liquid crystal alignment agent from the polymer (A) produced by the diamine compound of the formula (I), and can produce the liquid crystal display element. The parts have low residual image problems, stable alignment ability and high humidity resistance and high temperature, which can provide stable and good directional quality.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

Claims (10)

A diamine compound having the structure shown in formula (I): Wherein X is -O- or -COO-, and the L and Z systems are each independently a cyclohexane group, a phenyl group or a single bond, and the L and the Z are not simultaneously a single bond, and M is a carbon number of 1 to 10 The alkyl group or an alicyclic group having a carbon number of 4 to 30. The diamine compound of claim 1, wherein the X is -O- or -COO-, the L and the Z series are each independently a cyclohexane group or a single bond, and the L and the Z are not simultaneously a single bond, The M is an alkyl group having 1 to 10 carbon atoms or an alicyclic group having 4 to 30 carbon atoms. A liquid crystal alignment agent comprising a polymer, wherein the reactant in the polymerization reaction comprises the diamine compound, the other diamine compound and the tetracarboxylic dianhydride as claimed in claim 1. The liquid crystal alignment agent of claim 3, wherein the X of the diamine compound according to claim 1 is -O- or -COO-, and the L and the Z series are each independently a cyclohexane group or a single bond. And L and Z are not simultaneously a single bond, and the M is an alkyl group having 1 to 10 carbon atoms or an alicyclic group having 4 to 30 carbon atoms. The liquid crystal aligning agent of claim 3, wherein the polymer is a polyamic acid, a polyimine or a quinone imine-proline copolymer. The liquid crystal alignment agent of claim 3, wherein the tetracarboxylic dianhydride comprises an aromatic tetracarboxylic dianhydride of 30 mol% or more. The liquid crystal alignment agent of claim 3, wherein the tetracarboxylic dianhydride comprises from 50 mole percent to 80 mole percent of the aromatic tetracarboxylic dianhydride. The liquid crystal alignment agent of claim 3, wherein the diamine compound according to claim 1 accounts for 3 moles to 20 moles of the total content of the diamine compound and the other diamine compound as claimed in claim 1 percentage. A liquid crystal alignment film formed of the liquid crystal alignment agent according to any one of claims 3 to 8. A liquid crystal display element comprising the liquid crystal alignment film of claim 9.