Patent TW-202146528-A (TW)
Title: Liquid crystal alignment agent for photo-alignment process, liquid crystal alignment film, and liquid crystal display component which may obtain high liquid crystal alignment by means of a photo-alignment process, and suppress a deviation of in-plane luminance during black display
Inventor: ISHIKAWA KAZUNORI
IPC: C08G73/10
Filed: 2021-03-22
Abstract: A subject of this invention is to provide a liquid crystal alignment agent for a photo-alignment process, which may obtain high liquid crystal alignment by means of a photo-alignment process, suppress a deviation of in-plane luminance during black display, and contrast improved liquid crystal display components. The solution is to provide a liquid crystal alignment agent for a photo-alignment process, which contains at least one polymer (A) selected from the group consisting of a polyimide precursor and an imidized polymer thereof. The polymer (A) has at least one repeating unit (a1) selected from the group consisting of a repeating unit represented by the following formula (1-a) and a repeating unit represented by the following formula (1-i), and at least one repeating unit (a2) selected from the group consisting of a repeating unit represented by the following formula (2-a) and a repeating unit represented by the following formula (2-i), and contains 1-20 mol% of the aforementioned repeating units (a1) of all repeating units. (In the formula, X1 represents a tetravalent organic group represented by the following formula (B), and X2 represents a tetravalent organic group represented by the following formula (C). R and Z each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. A plurality of R and Z may be the same or different from each other. Y1 and Y2 each independently represent a divalent organic group represented by the following formula (O). (In the formula, Rb1 to Rb4 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. L1 represents a single bond, -CH2-, -(CH2)n- (n is an integer from 2 to 18), or a group in which at least a part of -CH2- of the aforementioned -(CH2)n- is substituted by any one of -O-, -C(=O)- or -O-C(=O)-. Rc1 to Rc4 each independently represent a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and a fluorine atom, or a phenyl group, and at least one of Rc1 to Rc4 represents a group other than a hydrogen atom in the above definition). (Ar represents a benzene ring, a biphenyl structure, or a naphthalene ring, two Ars may be the same or different, and any hydrogen atom on the ring may be substituted with a monovalent organic group. Q2 represents -CH2-, -(CH2)n- (n is an integer from 2 to 18), or a group in which at least a part of -CH2- of the aforementioned -(CH2)n- is substituted by any one of -O-, -C(=O)- or -O-C(=O)-. p is an integer of 0 or 1. However, when p is 0, Ar represents a biphenyl structure, and when p is 1, at least one of the two Ars represents a naphthalene ring. * indicates a bonding part).