Triazine ring based polymers for photoinduced liquid crystal alignment, liquid crystal alignment layer containing the same, liquid crystal element using the alignment layer and method of manufacturing the same

A liquid crystal alignment agent containing triazine ring based polyimide polymer expressed by the following chemical formula (II):

• wherein R1 in the Chemical Formula (II) is selected from the following formula (1a) to (4a):
• wherein X in the above formula (1a) is one selected in from the following formula:
• wherein Y in the formula (1a) is one selected from the following formula:
• wherein the numerals 1, 2, 3, 4, 5, 6, 7, 8 or 9 in the above formula is one selected from the following formula:
• wherein, in the above formula (2a) and (3a), n is 0˜10, and the numerals 1, 2, 3, 4 and 5 are respectively selected from the following formula:
• wherein Y in the above formula (4a) is one selected from the following formula:
• wherein the numerals 1 and 2 in the above formula (4a) are respectively selected from the following formula:
• wherein R2 and R3 in the Chemical Formula (II) are amine moieties respectively derived from one selected from the group consisting of the following formulas:
• wherein R4 and R5 in the Chemical Formula (II) are carboxylic acid dianhydride moieties respectively derived from one selected from the group consisting of the following formulas:

A liquid crystal alignment agent containing triazine ring based polymer expressed by the following chemical formula (III):

• wherein R1 in the Chemical Formula (III) is one selected from the following formula (1a) to (4a):
• wherein X in the above formula (1a) is one selected from the following formula:
• wherein Y in the formula (1a) is one selected from the following formula:
• wherein the numerals 1, 2, 3, 4, 5, 6, 7, 8 or 9 in the above formula is one selected from the following formula:
• wherein, in the above formula (2a) and (3a), n is 0˜10, and the numerals 1, 2, 3, 4 and 5 are respectively selected from the following formula:
• wherein Y in the above formula (4a) is one selected from the following formula:
• wherein the numerals 1 and 2 in the above formula (4a) are respectively selected from the following formula:
• wherein R2 and R3 in the Chemical Formula (III) are amine moieties respectively derived from one selected from the group consisting of the following formulas:
• wherein R4 in the Chemical Formula (III) is a carboxylic acid moiety selected from the group consisting of the following formulas:
• wherein R5 in the Chemical Formula (III) is a carboxylic acid dianhydride moiety derived from one selected from the group consisting of the following formulas: