A polyamide acid, a method for producing the same, a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element
By controlling the reaction of dianhydride monomers through a stepwise feeding method, no free anhydride residue is left in the polyamic acid, which solves the problems of storage stability and liquid crystal contamination, improves the voltage retention rate of liquid crystal display elements and reduces image residue, making it suitable for high-resolution liquid crystal display panels.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN CAPCHEM TECH CO LTD
- Filing Date
- 2026-06-02
- Publication Date
- 2026-07-17
AI Technical Summary
In the prior art, the residue of free anhydride leads to poor storage stability of polyamic acid, serious liquid crystal contamination, and film defects, and it is difficult to completely eliminate and precisely control the polymer structure and properties through existing methods.
A stepwise feeding method is adopted. First, the low-reactivity dianhydride monomer G1 reacts with the diamine to ensure complete consumption. Then, the high-reactivity dianhydride monomer G2 is added to control the excess of diamine and ensure that all dianhydride monomers participate in the reaction to form amino-terminated polyamic acid, thus avoiding the residue of free anhydride.
It achieves high storage stability of polyamic acid, reduces liquid crystal contamination, improves the voltage retention rate of liquid crystal display elements, and reduces image retention, making it suitable for high-resolution, high-refresh-rate liquid crystal display panels.
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