Patent TW-202309251-A (TW)
Title: Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element
Inventor: TOYOTA Miki
IPC: C08G73/10
Filed: 2022-07-14
Abstract: Provided are: a liquid crystal alignment agent from which a liquid crystal alignment film having a high voltage retention rate even after being exposed to high temperature and high humidity for a long period of time; a liquid crystal alignment film obtained from said liquid crystal alignment agent; and a liquid crystal display element using same. This liquid crystal alignment agent contains the following component (A) and component (B). Component (A): At least one polymer (A) selected from the group consisting of polyimide precursors having repeating units (a1) of a unit represented by formula (1) and repeating units (a2) of a unit represented by formula (2), and polyimides which are imidized products of said polyimide precursors. However, said polymer (A) does not include repeating units (b3) of a unit represented by formula (3). Component (B): At least one polymer (B) selected from the group consisting of polyimide precursors having repeating units (b3) of a unit represented by formula (3), and polyimides which are imidized products of said polyimide precursors. (X1 and X2 each represent a tetravalent organic group. Y1 represents a divalent organic group having an oxazoline backbone. Y2 represents a divalent organic group having group-X-J. R and Z each independently represent a hydrogen atom or a monovalent organic group. In group-X-J described above, X represents a single bond, -(CH2)a- (a represents an integer of 1-15), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -COO-, -OCO-, -Ak-O-CO-CH=CH-** (** represents a binding hand bound to an aromatic hydrocarbon group having 6-40 carbon atoms in J, and Ak represents a divalent organic group having 1-10 carbon atoms), or -(A1)a0-((CH2)a1-A1)m1- (a0 represents an integer of 0 or 1, a1 represents an integer of 1-15, A1 represents -O- or -COO-, the above described definition independently applies to each A1 when there are more than one of A1, m1 represents an integer of 1-2, and the above described definition independently applies to each of a plurality of a1 when m1 equals 2). J represents a monovalent organic group having at least one group selected from the group consisting of alicyclic hydrocarbon groups having 4-40 carbon atoms and aromatic hydrocarbon groups having 6-40 carbon atoms. However, at least one hydrogen atom included in the alicyclic hydrocarbon group and the aromatic hydrocarbon group is substituted with a halogen atom, a halogen atom-containing alkyl group having 1-10 carbon atoms, a halogen atom-containing alkoxy group having 1-10 carbon atoms, an alkyl group having 3-10 carbon atoms, an alkoxy group having 3-10 carbon atoms, or an alkenyl group having 3-10 carbon atoms, and a carbon-carbon bond included in an arbitrarily defined methylene group in the above described groups is optionally interrupted by -O-.) (X3 represents a tetravalent organic group. Y3 represents a divalent organic group having an aromatic carboxy group. Each of the two R's and each of the two Z's respectively have the same meaning as R and Z in formula (1).).