Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display device

• US 9,505,981 B2
• Filed: 03/17/2015
• Issued: 11/29/2016
• Est. Priority Date: 03/25/2014
• Status: Active Grant

• Current Assignee: CHI MEI Corporation
• Original Assignee: CHI MEI Corporation
• Inventors: Chiou, Shin-Rong
• Primary Examiner(s): Chung, Susannah
• Assistant Examiner(s): Butcher, Robert T
• Application Number:
  US14/660,898
• Publication Number:
  US 20150275092A1
• Time in Patent Office: 623 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C08G 73/1042 Copolyimides derived from at least two different tetracarboxylic compounds or two different diamino compounds
• CPC Class Codes: C08G 73/1075 Partially aromatic polyimides
• CPC Class Codes: C08G 73/1078 wholly aromatic in the diamino moiety
• CPC Class Codes: C08J 2379/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• CPC Class Codes: C08L 79/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C09D 179/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C09K 19/56 Aligning agents
• CPC Class Codes: G02F 1/133711 by organic films, e.g. polymeric films
• CPC Class Codes: G02F 1/133723 Polyimide, polyamide-imide
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation
• CPC Class Codes: Y02P 20/582 Recycling of unreacted starting or intermediate materials

Abstract

A liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device are provided. The liquid crystal alignment agent includes a polymer composition (A-1) and a solvent (B). The polymer composition (A-1) is obtained by reacting a tetracarboxylic acid dianhydride compound (a) with a diamine compound (b). The diamine compound (b) includes at least one type of diamine (b-1) represented by formula (I) and at least one type of diamine (b-2) having the structure represented by formula (II). The liquid crystal alignment agent can be made into a liquid crystal display device having good uniformity of pretilt angle after ultraviolet irradiation.

Claims

1. A liquid crystal alignment agent, comprising:

a polymer composition (A-1); and

a solvent (B),

wherein the polymer composition (A-1) is obtained by reacting a tetracarboxylic acid dianhydride compound (a) with a diamine compound (b),

the diamine compound (b) comprises at least one type of a diamine (b-1) represented by formula (I) and at least one type of a diamine (b-2) having a structure represented by formula (II), wherein a molar ratio (b-1)/(b-2) of the diamine (b-1) represented by formula (I) and the diamine (b-2) having the structure represented by formula (II) is 0.05 to 1.5,

2. The liquid crystal alignment agent of claim 1, wherein the diamine (b-2) having the structure represented by formula (II) comprises a structure represented by formula (II-1), a structure represented by formula (II-2), or a combination of the two,

3. The liquid crystal alignment agent of claim 1, wherein based on a total number of moles of 100 moles of the diamine compound (b), a usage amount of the diamine (b-1) represented by formula (I) is 0.5 to 50 moles, and a usage amount of the diamine (b-2) having the structure represented by formula (II) is 10 to 80 moles.

4. The liquid crystal alignment agent of claim 1, wherein a molar ratio (b-1)/(b-2) of the diamine (b-1) represented by formula (I) and the diamine (b-2) having the structure represented by formula (II) is 0.1 to 1.3.

5. The liquid crystal alignment agent of claim 4, wherein a molar ratio (b-1)/(b-2) of the diamine (b-1) represented by formula (I) and the diamine (b-2) having the structure represented by formula (II) is 0.2 to 1.0.

6. A liquid crystal alignment film formed by the liquid crystal alignment agent of claim 1.

7. A liquid crystal display device, comprising the liquid crystal alignment film of claim 6.