Liquid crystal aligning agent composition, method for preparing liquid crystal alignment film using same, and liquid crystal alignment film using same

Abstract

A liquid crystal aligning agent composition for preparing a liquid crystal alignment film having enhanced stability and exhibiting excellent electrical characteristics, a method for preparing a liquid crystal alignment film using the same, and a liquid crystal alignment film and a liquid crystal display device using the liquid crystal alignment film.

Claims

1. A liquid crystal aligning agent composition comprising: a first polymer for a liquid crystal aligning agent including one or more repeating units selected from the group consisting of a repeating unit represented by Chemical Formula 1, a repeating unit represented by Chemical Formula 2, and a repeating unit represented by Chemical Formula 3; a second polymer for a liquid crystal aligning agent including one or more repeating units selected from the group consisting of a repeating unit represented by Chemical Formula 4, a repeating unit represented by Chemical Formula 5, and a repeating unit represented by Chemical Formula 6; and a third polymer for a liquid crystal aligning agent including one or more repeating units selected from the group consisting of a repeating unit represented by Chemical Formula 7, a repeating unit represented by Chemical Formula 8, and a repeating unit represented by Chemical Formula 9: ##STR00018## wherein, in the Chemical Formulae 1 to 9, at least one of R.sub.1 and R.sub.2 is an alkyl group having 1 to 10 carbon atoms and the other is hydrogen, at least one of R.sub.3 and R.sub.4 is an alkyl group having 1 to 10 carbon atoms and the other is hydrogen, at least one of R.sub.5 and R.sub.6 is an alkyl group having 1 to 10 carbon atoms and the other is hydrogen, and X.sub.1 to X.sub.9 are each independently a tetravalent organic group represented by Chemical Formula 10, ##STR00019## wherein, in the Chemical Formula 10, R.sub.7 to R.sub.12 are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, L.sub.1 is any one selected from the group consisting of a single bond, —O—, —CO—, —COO—, —S—, —SO—, —SO.sub.2—, —CR.sub.13R.sub.14—, —(CH.sub.2).sub.Z—, —O(CH.sub.2).sub.ZO—, COO(CH.sub.2).sub.ZOCO—, —CONH—, phenylene, and a combination thereof, wherein R.sub.13 and R.sub.14 are each independently hydrogen, or an alkyl group or a fluoroalkyl group having 1 to 10 carbon atoms, z is an integer of 1 to 10, and Y.sub.7 to Y.sub.9 are each independently a divalent organic group represented by Chemical Formula 11, ##STR00020## wherein, in the Chemical Formula 11, R.sub.15 and R.sub.16 are each independently hydrogen, a halogen, a cyano, a nitrile, an alkyl having 1 to 10 carbon atoms, an alkenyl having 1 to 10 carbon atoms, an alkoxy having 1 to 10 carbon atoms, a fluoroalkyl having 1 to 10 carbon atoms, or a fluoroalkoxy having 1 to 10 carbon atoms, p and q are each independently an integer of 0 to 4, L.sub.2 is a single bond, —O—, —CO—, —S—, —SO.sub.2—, —C(CH.sub.3).sub.2—, —C(CF.sub.3).sub.2—, —CONH—, —COO—, —(CH.sub.2).sub.y—, —O(CH.sub.2).sub.yO—, —O(CH.sub.2).sub.y—, —NH—, —NH(CH.sub.2).sub.y—NH—, —NH(CH.sub.2).sub.yO—, —OCH.sub.2—C(CH.sub.3).sub.2—CH.sub.2O—, —COO—(CH.sub.2).sub.y—OCO—, or —OCO—(CH.sub.2).sub.y—COO—, y is an integer of 1 to 10, k and m are each independently an integer of 0 to 3, n is an integer of 0 to 3, and Y.sub.1 to Y.sub.3 are each independently a divalent organic group represented by Chemical Formula 12, ##STR00021## wherein, in the Chemical Formula 12, T is a tetravalent organic group represented by the Chemical Formula 10, D.sub.1 and D.sub.2 are each independently an alkylene group having 1 to 20 carbon atoms, a heteroalkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a heteroarylene group having 2 to 20 carbon atoms, and Y.sub.4 to Y.sub.6 are each independently a divalent organic group represented by Chemical Formula 13, ##STR00022## wherein, in Chemical Formula 13, A is a Group 16 element selected from the group of oxygen, sulfur, selenium, tellurium, and polonium, R′ is hydrogen or an alkyl having 1 to 10 carbon atoms, a is an integer of 0 to 3, and at least one of Z.sub.1 to Z.sub.4 is nitrogen, and the rest are carbon.

2. The liquid crystal aligning agent composition of claim 1, wherein in the Chemical Formula 13, one of Z.sub.1 to Z.sub.4 is nitrogen, and the rest are carbon.

3. The liquid crystal aligning agent composition of claim 1, wherein in the Chemical Formula 13, one of Z.sub.1 to Z.sub.4 is nitrogen, the rest are carbon, and Z.sub.2 and Z.sub.4 are carbon.

4. The liquid crystal aligning agent composition of claim 1, wherein in the Chemical Formula 13, A is oxygen, and a is 0.

5. The liquid crystal aligning agent composition of claim 1, wherein the Chemical Formula 13 includes at least one repeating unit selected from the group consisting of Chemical Formulae 13-1, 13-2, and 13-3: ##STR00023## wherein, in the Chemical Formulae 13-1 to 13-3, A, Z.sub.1 to Z.sub.4, R′, and a are as defined in claim 1.

6. The liquid crystal aligning agent composition of claim 1, wherein, in the Chemical Formula 12, T is Chemical Formula 10-1 or 10-2, and D.sub.1 and D.sub.2 are each independently a phenylene group: ##STR00024##

7. The liquid crystal aligning agent composition of claim 1, wherein the second polymer is contained in an amount of 10 to 1000 parts by weight, based on 100 parts by weight of the first polymer.

8. The liquid crystal aligning agent composition of claim 1, wherein the third polymer for a liquid crystal aligning agent is an amount of 10 to 1000 parts by weight, based on 100 parts by weight of the first polymer.

9. A method for preparing a liquid crystal alignment film comprising the steps of: coating the liquid crystal aligning agent composition of claim 1 onto a substrate to form a coating film; drying the coating film; alignment treatment by irradiating the coating film immediately after the drying step with light or rubbing the coating film; and heat-treating and curing the alignment-treated coating film.

10. The method for preparing a liquid crystal alignment film of claim 9, wherein the liquid crystal aligning agent composition is dissolved or dispersed in an organic solvent.

11. The method for preparing a liquid crystal alignment film of claim 9, wherein the step of drying the coating film is performed at 50° C. to 150° C.

12. The method for preparing a liquid crystal alignment film of claim 9, wherein the light in the alignment treatment step, is polarized ultraviolet rays having a wavelength of 150 nm to 450 nm.

13. The method for preparing a liquid crystal alignment film of claim 9, wherein in the step of curing the coating film, the temperature of the heat treatment is 150° C. to 300° C.

14. A liquid crystal alignment film comprising an aligned cured product of the liquid crystal aligning agent composition of claim 1.

15. A liquid crystal display device comprising the liquid crystal alignment film of claim 14.

16. A liquid crystal alignment film produced by the method of claim 9.

17. A liquid crystal display device comprising the liquid crystal alignment film of claim 16.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) The prevention invention will be described in more detail by way of examples.

(2) However, these examples are given for illustrative purposes only, and the scope of the invention is not intended to be limited by these examples.

PREPARATION EXAMPLE

Preparation Example 1: Preparation of Diamine DA1-1

(3) Diamine DA1-1 was synthesized according to the following reaction scheme.

(4) ##STR00013##

(5) Specifically, CBDA (cyclobutane-1,2,3,4-tetracarboxylic dianhydride, Compound 1) and 4-nitroaniline were dissolved in DMF (dimethylformamide) to prepare a mixture. Then, the mixture was reacted at about 80° C. for about 12 hours to prepare an amic acid of Compound 2. Subsequently, the amic acid was dissolved in DMF, and acetic anhydride and sodium acetate were added thereto to prepare a mixture. Then, the amic acid contained in the mixture was imidized at about 90° C. for about 4 hours to obtain Compound 3. The imide of Compound 3 thus obtained was dissolved in DMAc (dimethylacetamide), and then Pd/C was added thereto to prepare a mixture. The resulting mixture was reduced at about 45° C. under hydrogen pressure of about 6 bar for about 20 hours to prepare diamine DA1-1.

Preparation Example 2: Preparation of Diamine DA1-2

(6) ##STR00014##

(7) DA1-2 having the above structure was prepared in the same manner as in Preparation Example 1, except that DMCBDA (1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid dianhydride) was used instead of CBDA (cyclobuthane-1,2,3,4-tetracarboxylic dianhydride).

Preparation Example 3: Preparation of Diamine DA2

(8) ##STR00015##

(9) 17.1 g (100 mmol) of 2-chloro-5-nitropyridine (Compound 7) and 12.5 g (98.6 mmol) of 4-nitrophenol (Compound 8) were completely dissolved in 200 mL of dimethyl sulfoxide (DMSO).

(10) 27.2 g (200 mmol) of potassium carbonate (K.sub.2C.sub.3) was then added thereto and stirred at room temperature for about 16 hours. When the reaction was completed, the reaction product was added to a container containing about 500 mL of water and stirred for about 1 hour. A solid obtained by filtration was washed with about 200 mL of water and about 200 mL of ethanol to synthesize 16 g (61.3 mmol) of Compound 9 (yield: 57%).

(11) ##STR00016##

(12) Compound 9 was dissolved in about 200 mL of a 1:1 mixed solution of ethyl acetate (EA) and THE 0.8 g of palladium (Pd)/carbon (C) was then added thereto and stirred under a hydrogen atmosphere for 12 hours. After completion of the reaction, the reaction mixture was filtered through a celite pad and the filtrate was concentrated to prepare 11 g of diamine compound DA2 (pODA) (yield: 89%).

SYNTHESIS EXAMPLE

(13) A first polymer, a second polymer, and a third polymer were synthesized using the reactants shown in Table 1 below. Concrete synthesis conditions of respective Synthesis Examples 1 to 8 are shown in Table 1 below.

(14) TABLE-US-00001 TABLE 1 First Synthesis Diamine Acid polymer Example anhydride Synthesis Preparation DMCBDA Example 1 (P-1) Example 1 (DA1-1) Synthesis Preparation DMCBDA Example 2 (P-2) Example 2 (DA1-2) Comparative p-PDA DMCBDA Synthesis Example 1 (S-1) Second Synthesis Example Diamine Acid polymer anhydride Synthesis Preparation BT-100 Example 3 (Q-1) Example 3 (DA2) Synthesis Preparation CHDA Example 4 (Q-2) Example 3 (DA2) Synthesis Preparation PMDA Example 5 (Q-3) Example 3 (DA2) Comparative Chemical BT-100 Synthesis Formula A Example 2 (S-2) Third Synthesis Example Diamine Acid polymer anhydride Synthesis ODA BPDA Example 6 (R-1) Synthesis EODA BPDA Example 7 (R-2) Synthesis MDA BPDA Example 8 (R-3)

Synthesis Examples 1 and 2: Synthesis of First Polymer

Synthesis Example 1: Preparation of Polymer P-1 for Liquid Crystal Aligning Agent

(15) 5.0 g (13.3 mmol) of DA1-1 prepared in Preparation Example 1 was completely dissolved in 71.27 g of anhydrous N-methyl pyrrolidone (NMP). 2.92 g (13.03 mmol) of 1,3-dimethyl-cyclobuthane-1,2,3,4-tetracarboxylic dianhydride (DMCBDA) was then added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare a polymer P-1 for a liquid crystal aligning agent.

(16) As a result of confirming the molecular weight of the polymer P-1 through GPC, the number average molecular weight (Mn) was 15,500 g/mol, and the weight average molecular weight (Mw) was 31,000 g/mol. Further, the monomer structure of the polymer P-1 is determined by the equivalent ratio of the monomers used, and the ratio of the imide structure in the molecule was 50.5%, while the ratio of the amic acid structure was 49.5%.

Synthesis Example 2: Preparation of Polymer P-2 for Liquid Crystal Aligning Agent

(17) 5.376 g of DA1-2 prepared in Preparation Example 2 was first dissolved in 74.66 g of NMP. 2.92 g of 1,3-dimethyl-cyclobuthane-1,2,3,4-tetracarboxylic dianhydride (DMCBDA) was then added thereto and stirred at room temperature for about 16 hours. Then, the polymer P-2 was prepared in the same manner as in Synthesis Example 1.

(18) As a result of confirming the molecular weight of the polymer P-2 through GPC, the number average molecular weight (Mn) was 17,300 g/mol, while the weight average molecular weight (Mw) was 34,000 g/mol. Further, as for the polymer P-2, the ratio of the imide structure in the molecule was 50.5%, and the ratio of the amic acid structure was 49.5%.

Comparative Synthesis Example 1: Synthesis of First Polymer

Comparative Synthesis Example 1: Preparation of Polymer S-1 for Liquid Crystal Aligning Agent

(19) A polymer S-1 for a liquid crystal aligning agent was prepared in the same manner as in Synthesis Example 1, except that para-phenylenediamine (p-PDA) was used instead of DA1-1 prepared in Preparation Example 1.

Synthesis Examples 3 to 5: Synthesis of Second Polymer

Synthesis Example 3: Preparation of Polymer Q-1 for Liquid Crystal Aligning Agent

(20) 18.082 g (0.090 mmol) of the diamine DA2 prepared in Preparation Example 3 was completely dissolved in 225.213 g of anhydrous N-methyl pyrrolidone (NMP).

(21) 18.228 g (0.084 mmol) of tetrahydro-[3,3′-bifuran]-2,2′,5,5′-tetraone (BT100) was then added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare a polymer Q-1 for a liquid crystal alignment agent. As a result of confirming the molecular weight of the polymer Q-1 through GPC, the weight average molecular weight (Mw) was 21,000 g/mol.

Synthesis Example 4: Preparation of Polymer Q-2 for Liquid Crystal Aligning Agent

(22) 19.907 g (0.099 mmol) of the diamine DA2 prepared in Preparation Example 3 was completely dissolved in 29.676 g of anhydrous N-methyl pyrrolidone (NMP).

(23) 20.624 g (0.092 mmol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA) was then added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare a polymer Q-2 for a liquid crystal alignment agent. As a result of confirming the molecular weight of the polymer Q-2 through GPC, the weight average molecular weight (Mw) was 19,780 g/mol.

Synthesis Example 5: Preparation of Polymer Q-3 for Liquid Crystal Aligning Agent

(24) 19.840 g (0.099 mmol) of the diamine DA2 prepared in Preparation Example 3 was completely dissolved in 225.213 g of anhydrous N-methyl pyrrolidone (NMP).

(25) 20.0 g (0.092 mmol) of pyromellitic dianhydride (PMDA) was then added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare a polymer Q-3 for a liquid crystal alignment agent. As a result of confirming the molecular weight of the polymer Q-3 through GPC, the weight average molecular weight (Mw) was 27,000 g/mol.

Synthesis Examples 6 to 8: Synthesis of Third Polymer

Synthesis Example 6: Preparation of Polymer R-1 for Liquid Crystal Aligning Agent

(26) 19.743 g (0.099 mmol) of 4,4′-oxydianiline (ODA) was completely dissolved in 225.208 g of anhydrous N-methyl pyrrolidone (NMP).

(27) 27.068 g (0.092 mmol) of 3,3′,4,4′-biphenyl tetracarboxylic acid dianhydride (BPDA) was then added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare a polymer R-1 for a liquid crystal alignment agent. As a result of confirming the molecular weight of the polymer R-1 through GPC, the weight average molecular weight (Mw) was 26,800 g/mol.

Synthesis Example 7: Preparation of Polymer R-2 for Liquid Crystal Aligning Agent

(28) 17.856 g (0.073 mmol) of 4,4′-(ethane-1,2-diylbis(oxy))dianiline (EODA) was completely dissolved in 214.516 g of anhydrous N-methyl pyrrolidone (NMP).

(29) 27.068 g (0.068 mmol) of 3,3′,4,4′-biphenyl tetracarboxylic acid dianhydride (BPDA) was then added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare a polymer R-2 for a liquid crystal alignment agent. As a result of confirming the molecular weight of the polymer R-2 through GPC, the weight average molecular weight (Mw) was 26,700 g/mol.

Synthesis Example 8: Preparation of Polymer R-3 for Liquid Crystal Aligning Agent

(30) 19.548 g (0.089 mmol) of 4,4′-methylenedianiline (MDA) was completely dissolved in 224.218 g of anhydrous N-methyl pyrrolidone (NMP).

(31) 27.068 g (0.092 mmol) of 3,3′,4,4′-biphenyl tetracarboxylic acid dianhydride (BPDA) was then added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare a polymer R-3 for a liquid crystal alignment agent. As a result of confirming the molecular weight of the polymer R-3 through GPC, the weight average molecular weight (Mw) was 22650 g/mol.

Comparative Synthesis Example: Preparation of Second Polymer

Comparative Synthesis Example 2: Preparation of Polymer S-2 for Liquid Crystal Aligning Agent

(32) A polymer S-2 for a liquid crystal aligning agent was prepared in the same manner as in Synthesis Example 3, except that a compound represented by the following Chemical Formula A was used instead of the diamine DA2 prepared in Preparation Example 3.

(33) ##STR00017##

Examples and Comparative Examples: Preparation of Liquid Crystal Aligning Agent Composition

(34) A first polymer, a second polymer, and a third polymer were dissolved in a mixed solvent of NMP, GBL, and 2-butoxyethanol in a composition as shown in Table 2 below, and the obtained solution was subjected to pressure filtration through a filter having a pore size of 0.1 tan made of poly(tetrafluoroethylene) to prepare a liquid crystal aligning agent composition.

Experimental Example

(35) A liquid crystal cell was prepared by using the liquid crystal aligning agent compositions prepared in the examples and comparative examples.

(36) Specifically, the liquid crystal aligning agent composition was coated onto each of upper and lower substrates for the voltage holding ratio (VHR) in which an electrode having a thickness of 60 nm and an area of 1 cm×1 cm was patterned on a rectangular glass substrate having a size of 2.5 cm×2.7 cm using a spin coating method. Then, the substrates onto which the liquid crystal aligning agent composition was coated were placed on a hot plate at about 70° C. and dried for 3 minutes to evaporate the solvent. In order to subject the thus-obtained coating film to alignment treatment, ultraviolet rays of 254 nm were irradiated with intensity of 0.1 to 1 J/cm.sup.2 using an exposure apparatus in which a linear polarizer was adhered to the coating film of each of the upper/lower plates. Subsequently, the alignment-treated upper/lower plates were calcinated (cured) in an oven at about 230° C. for 30 minutes to obtain a coating film having a thickness of 0.1 μm. Then, a sealing agent impregnated with ball spacers having a size of 4.5 μm was coated onto the edge of the upper plate excluding the liquid crystal injection hole. Then, the alignment films formed on the upper plate and the lower plate were aligned such that they faced each other and the alignment directions are aligned with each other, and then the upper and lower plates were bonded together and the sealing agent was UV- and heat-cured to prepare an empty cell. Subsequently, a liquid crystal was injected into the empty cell, and the injection port was sealed with a sealing agent to prepare a liquid crystal alignment cell.

(37) 1) Evaluation of Liquid Crystal Alignment Properties

(38) Polarizing plates were adhered to the upper and lower plates of the liquid crystal cell prepared as above so that their polarization axes are perpendicular to each other. The liquid crystal cell to which the polarizing plates were adhered was then placed on a backlight of brightness of 7000 cd/m.sup.2, and light leakage was observed with the naked eye. At this time, if the alignment properties of the liquid crystal alignment film are excellent and the liquid crystal is arranged well, light does not pass through the upper and lower polarizing plates, and it is observed to be dark without defects. In this case, the alignment properties are evaluated as ‘good’, and when light leakage such as a liquid crystal flow mark or a bright spot is observed, it is evaluated as ‘poor’. The results are shown in Table 2 below.

(39) 2) Measurement of Voltage Holding Ratio (VHR)

(40) The voltage holding ratio (VHR), which is an electrical characteristic of the prepared liquid crystal alignment cell, was measured using 6254C equipment available from TOYO Corporation. The voltage holding ratio (VHR) was measured under the conditions of 1 Hz and 60° C. (VHR 60° C. and 1 Hz n-LC conditions). The measurement results of the voltage holding ratio (VHR) of the liquid crystal alignment cell are shown in Table 2 below.

(41) 3) Evaluation of Alignment Stability (AC Afterimage)

(42) Polarizing plates were adhered to the upper plate and lower plate of the liquid crystal cell so that their polarization axes are perpendicular to each other. The liquid crystal cell to which the polarizing plates were adhered was adhered onto a backlight of 7000 cd/m.sup.2, and the brightness in a black mode was measured using PR-880 equipment which is a device for measuring brightness. Then, the liquid crystal cell was driven at room temperature for 24 hours with an AC voltage of 5 V. Thereafter, the brightness in a black mode was measured in the same manner as described above in a state in which the voltage of the liquid crystal cell was turned off. The difference between the initial brightness (L0) measured before driving the liquid crystal cell and the final brightness (L1) measured after driving the liquid cell was divided by the value of the initial brightness (L0) and multiplied by 100, thereby calculating the brightness variation. As the calculated brightness variation is closer to 0%, it means that the alignment stability is excellent. The level of afterimage was evaluated through the measurement result of such brightness variation according the following criteria. AC afterimage is preferably minimized. In the measurement results, if the brightness variation is less than 10%, it is evaluated as “excellent”; if the brightness variation is 10% to 20%, it is evaluated as “ordinary”; and if the brightness variation is greater than 20%, it is evaluated as “poor”. The results are shown in Table 2 below.

(43) TABLE-US-00002 TABLE 2 Weight ratio of polymer Liquid (1.sup.st polymer: 3.sup.rd crystal First Second Third polymer: 2.sup.nd alignment Alignment Category polymer polymer polymer polymer) property stability VHR(%) Example 1 P-1 Q-1 R-1 5:4:1 Good Excellent 77 Example 2 P-1 Q-2 R-1 5:4:1 Good Excellent 78 Example 3 P-1 Q-3 R-1 5:4:1 Good Excellent 75 Example 4 P-1 Q-1 R-2 5:4:1 Good Excellent 80 Example 5 P-1 Q-2 R-2 5:4:1 Good Excellent 82 Example 6 P-1 Q-3 R-2 5:4:1 Good Excellent 77 Example 7 P-1 Q-1 R-3 5:4:1 Good Excellent 79 Example 8 P-1 Q-2 R-3 5:4:1 Good Excellent 77 Example 9 P-1 Q-3 R-3 5:4:1 Good Excellent 78 Example 10 P-2 Q-1 R-1 5:4:1 Good Excellent 83 Example 11 P-2 Q-2 R-1 5:4:1 Good Excellent 82 Example 12 P-2 Q-3 R-1 5:4:1 Good Excellent 81 Example 13 P-2 Q-1 R-2 5:4:1 Good Excellent 79 Example 14 P-2 Q-2 R-2 5:4:1 Good Excellent 80 Example 15 P-2 Q-3 R-2 5:4:1 Good Excellent 81 Example 16 P-2 Q-1 R-3 5:4:1 Good Excellent 79 Example 17 P-2 Q-2 R-3 5:4:1 Good Excellent 79 Example 18 P-2 Q-3 R-3 5:4:1 Good Excellent 80 Example 19 P-2 Q-1 R-1 2:7:1 Good Excellent 81 Example 20 P-2 Q-1 R-1 3:5:2 Good Excellent 79 Example 21 P-2 Q-1 R-1 5:2:3 Good Excellent 77 Comparative P-1 — R-1 5:5 Good Ordinary 63 Example 1 Comparative P-2 — R-1 5:5 Good Excellent 65 Example 2 Comparative P-1 Q-1 — 5:5 Poor Poor 78 Example 3 Comparative S-1 Q-1 R-1 5:4:1 Poor Poor 48 Example 4 Comparative P-1 S-2 R-1 5:4:1 Poor Poor 47 Example 5

(44) As shown in Table 2, it can be confirmed that in the case of Examples 1 to 21 in which all three polymers of the first polymer, the second polymer, and the third polymer are mixed, it is possible to realize a high voltage holding ratio of 75% or more together with excellent liquid crystal alignment property and alignment stability at the same time.

(45) Meanwhile, when comparing Comparative Example 4 with Example 1, it is confirmed that when the first polymer synthesized by using a specific diamine synthesized in Preparation Example 1 as in Example 1 is used, it is possible to achieve superior liquid crystal alignment properties and electrical characteristics.

(46) In addition, when comparing Comparative Examples 5 with Example 1, it is confirmed that when the second polymer synthesized by using the specific diamine synthesized in Preparation Example 3 as in Example 1 is used, it is possible to achieve superior liquid crystal alignment properties and electrical characteristics.