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CN-121991706-A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element

CN121991706ACN 121991706 ACN121991706 ACN 121991706ACN-121991706-A

Abstract

The invention relates to the technical field of LCD material display application, in particular to a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display element. The liquid crystal aligning agent comprises polyimide precursor and/or polyimide obtained by imidizing the polyimide precursor, wherein the polyimide precursor is obtained by carrying out polymerization reaction on diamine monomer and dianhydride monomer and reacting with a terminal end capping agent, the diamine monomer comprises at least one of o-phenylenediamine and m-phenylenediamine and p-phenylenediamine, and the ratio of the molar quantity of the p-phenylenediamine to the total molar quantity of the o-phenylenediamine and m-phenylenediamine is (990-999) (1-10). The invention takes p-phenylenediamine as a main diamine monomer, combines at least one of o-phenylenediamine and m-phenylenediamine, adopts a blocking agent for blocking, can remarkably regulate and control the molecular weight, and utilizes the rigidity of a para-structure and the regulation of free volume and chain stacking of a meta-structure or a large-volume structure to improve the fluidity of the whole orientation agent.

Inventors

  • LAN SONG
  • YAN YANHUA
  • JIANG XISONG
  • GENG LIFENG

Assignees

  • 深圳新宙邦科技股份有限公司
  • 深圳市赛美科电子材料有限公司

Dates

Publication Date
20260508
Application Date
20260408

Claims (8)

  1. 1. A liquid crystal aligning agent is characterized by comprising a polyimide precursor and/or polyimide obtained by imidizing the polyimide precursor, wherein the polyimide precursor is obtained by carrying out polymerization reaction on diamine monomers and dianhydride monomers and reacting with a terminal end capping agent, the diamine monomers comprise at least one of o-phenylenediamine and m-phenylenediamine and p-phenylenediamine, and the ratio of the molar quantity of the p-phenylenediamine to the total molar quantity of the o-phenylenediamine and m-phenylenediamine is (990-999): (1-10).
  2. 2. The liquid crystal aligning agent according to claim 1, wherein the end-capping agent comprises any one of 4-chloroaniline, 4-fluoroaniline, aniline.
  3. 3. The liquid crystal aligning agent according to claim 1, wherein the ratio of the molar amount of p-phenylenediamine to the molar total amount of o-phenylenediamine and m-phenylenediamine to the molar amount of the end-capping agent is (990-999): (1-10): 1.
  4. 4. A liquid crystal aligning agent according to any one of claims 1 to 3, wherein the polyimide precursor is represented by structural formula 1: Structure 1 Wherein X 1 is X 2 is X 3 is W is 、 、 Y is a divalent organic group, ar is a tetravalent organic group, d is a= (1-9) 1, a (b+c) = (990-999) is (1-10), and b and c are not 0 at the same time.
  5. 5. The liquid crystal aligning agent according to claim 4, wherein Ar is at least one selected from the following structures: 。
  6. 6. the liquid crystal aligning agent according to claim 4, wherein Y is at least one selected from the following structures:
  7. 7. a liquid crystal alignment film, characterized in that it is obtained by coating and baking the liquid crystal alignment agent according to any one of claims 1 to 6.
  8. 8. A liquid crystal display element comprising the liquid crystal alignment film according to claim 7.

Description

Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element Technical Field The invention relates to the technical field of LCD material display application, in particular to a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display element. Background Liquid crystal display elements are now being widely used as display devices that achieve light weight and thin profile. A liquid crystal display device is generally composed of a liquid crystal, a liquid crystal alignment film, an electrode, a substrate, and the like, and a polyimide-based liquid crystal alignment film is widely used as a liquid crystal alignment film which is a film for controlling an alignment state of liquid crystal molecules. In general, a liquid crystal alignment film is aligned by rubbing a surface of the liquid crystal alignment film with a cloth of a raw material such as rayon, and the rubbing alignment treatment can be performed by a simple apparatus with effective and excellent results, but rubbing chips generated during rubbing process pollute the environment and cause defective display to the product, so that a photo alignment method is widely used. The liquid crystal alignment film material is generally Polyimide (PI) which is generally obtained by imidizing polyamic acid (Polyamide acid, PAA) included in a liquid crystal alignment agent. In the polyamic acid system, the polymer is mainly obtained by polymerizing anhydride and diamine. How to regulate the molecular weight of the whole polyimide system to obtain a polyimide orientation agent with higher fluidity is a technical problem in the field. Disclosure of Invention In order to solve the technical problems, the invention provides a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display element, wherein p-phenylenediamine and/or m-phenylenediamine are introduced while p-phenylenediamine is used, so that the liquid crystal aligning agent can be used for simultaneously considering the processability, the thermal stability and the aligning capability of various diamines. The invention adopts the following technical scheme: In a first aspect, the invention provides a liquid crystal aligning agent, which comprises a polyimide precursor and/or polyimide obtained by imidizing the polyimide precursor, wherein the polyimide precursor is obtained by carrying out polymerization reaction on diamine monomers and dianhydride monomers and reacting with a terminal end capping agent, the diamine monomers comprise at least one of o-phenylenediamine and m-phenylenediamine and p-phenylenediamine, and the ratio of the molar quantity of the p-phenylenediamine to the total molar quantity of the o-phenylenediamine and m-phenylenediamine is (990-999): (1-10). Further, the end capping agent comprises any one of 4-chloroaniline, 4-fluoroaniline and aniline. Further, the ratio of the molar quantity of the p-phenylenediamine to the molar total quantity of the o-phenylenediamine and the m-phenylenediamine to the molar quantity of the end capping agent is (990-999): (1-10): 1. Further, the polyimide precursor is represented by structural formula 1: Structure 1 Wherein X 1 isX 2 isX 3 isW is、、Y is a divalent organic group, ar is a tetravalent organic group, d is a= (1-9) 1, a (b+c) = (990-999) is (1-10), and b and c are not 0 at the same time. Further, ar is selected from at least one of the following structures: 。 Further, Y is selected from at least one of the following structures: In a second aspect, the invention also provides a liquid crystal alignment film, which is obtained by coating and baking the liquid crystal alignment agent. In a third aspect, the present invention also provides a liquid crystal display element including the above liquid crystal alignment film. The liquid crystal aligning agent of the invention takes at least one of p-phenylenediamine and o-phenylenediamine as diamine monomer, adopts a blocking agent for blocking, can obviously regulate and control the molecular weight, and utilizes the rigidity of a para-structure and the regulation of free volume and chain stacking of a meta-or large-volume structure to improve the fluidity of the whole aligning agent, so that the liquid crystal aligning agent can take into account the processability, the thermal stability and the aligning capability of various diamines. Detailed Description The following description of the embodiments of the present invention will be made clearly and completely in connection with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention. The invention provides a liquid crystal aligning agent, which