Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element

Patent metadata

Field	Value
Publication number	US-10761375-B2
Application number	US-201615758380-A
Country	US
Kind code	B2
Filing date	Sep 13, 2016
Priority date	Sep 16, 2015
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

The present invention provides the following: a photo alignment method-use liquid crystal aligning agent used to obtain a photo alignment method-use liquid crystal alignment film that does not cause bright spots even when negative liquid crystals are used, and that is capable of achieving good after-image characteristics; a liquid crystal alignment film obtained from the liquid crystal aligning agent; and a liquid crystal display element provided with the liquid crystal aligning agent. Provided is the liquid crystal aligning agent which contains a polyimide or polyimide precursor obtained from a reaction between: a tetracarboxylic acid dianhydride represented by formula (1) (in the formula, X 1 is as set forth in the present specification) or a derivative thereof; and a diamine component that contains a diamine represented by formula (2) (in the formula, R 1 , Z 1 and n are as set forth in the present specification).

First claim

The invention claimed is:

1. A liquid crystal alignment agent, comprising:
a polyimide or polyimide precursor,
wherein the polyimide or polyimide precursor is obtained by reacting a tetracarboxylic dianhydride of formula (1):

or a derivative thereof,
wherein X 1 is a tetravalent organic group, with a diamine component comprising a diamine of formula (2):

wherein
R 1 independently at each occurrence is a hydrogen atom, a methyl group or a fluorine atom, at least one R 1 is a methyl group or a fluorine atom;
Z 1 independently at each occurrence is a hydrogen atom or an optionally substituted C1-6 alkyl, C2-6 alkenyl or C2-6 aralkyl group; and
n 1 is 1 or 2.

2. The liquid crystal alignment agent of claim 1 ,
wherein the polyimide or polyimide precursor comprises a structural unit of formula (I):

wherein
R 1 independently at each occurrence is a hydrogen atom, a methyl group or a fluorine atom, at least one R 1 is a methyl group or a fluorine atom;
R 2 independently at each occurrence is a hydrogen atom or a C1-6 alkyl group;
X 1 is a group selected from the group consisting of formulae (X1-1) to (X1-9):

wherein R 3 , R 4 , R 5 and R 6 are each independently a hydrogen atom, a halogen atom, a C1-6 alkyl group, a C2-6 alkenyl group, a C2-6 alkynyl group or a phenyl group;
Z 1 independently at each occurrence is a hydrogen atom or an optionally substituted C1-6 alkyl, C2-6 alkenyl or C2-6 aralkyl group; and
n 1 is 1 or 2.

3. The liquid crystal alignment agent of claim 1 ,
wherein X 1 is a group of formula (X1-1):

wherein R 3 , R 4 , R 5 and R 6 are each independently a hydrogen atom, a halogen atom, a C1-6 alkyl group, a C2-6 alkenyl group, a C2-6 alkynyl group or a phenyl group.

4. The liquid crystal alignment agent of claim 2 ,
wherein the polyimide or polyimide precursor comprises the structural units of the formula (I) in a proportion of not less than 20% by mole relative to the total structural units.

5. A liquid crystal alignment film obtained using the liquid crystal alignment agent of claim 1 .

6. A liquid crystal alignment film obtained by applying the liquid crystal alignment agent of claim 1 onto a substrate and subjecting the agent-applied substrate to photoalignment.

7. A liquid crystal display device, comprising the liquid crystal alignment film of claim 5 .

Assignees

• Nissan Chemical Ind Ltd

Inventors

• Suzuki Kanako
• Kawano Yuta
• Goto Kohei
• Katayama Masaaki

Classifications

• C09K2019/548

  stabilizing the alignment; Polymer stabilized alignment · CPC title

• C09K19/588

  Heterocyclic compounds · CPC title

• C09K19/586

  Optically active dopants; chiral dopants · CPC title

• C09K19/14

  linked by a carbon chain · CPC title

• C08G73/10 Primary

  Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors · CPC title