액정분자의 선경사각 형성을 위한 새로운 감광성 폴리이미드 수직배향막의 합성 및 특성연구 = Syntheses and Characterization of Novel Photo-Alignment Layer for VA Mode LCD

다국어 초록 (Multilingual Abstract)

In VA mode LCD, photo-alignment method using RM (reactive mesogen) has been widely investigated during the last decade. When the liquid crystal is tilted along with the applied electric field, the photo-polymerization of RM can keep the tilted state of liquid crystal, and then, when electric field is removed, the pre-tilted liquid crystal will be formed. The pre-tilted liquid crystal shows considerably improved response time. But polymerized RM make uneven surface of alignment layers and induce scattering of light decreasing contrast ratio. In this study, we synthesized new photo-crosslinkable polyimide alignment layer containing the photosensitive side chain as well as vertical alignment side chain for VA mode LCD. We coated the new photo-crosslinkable polyimide on the IPS substrates to make VA-IPS cells. VA-IPS cells using positive LC show fast decaying time as compared with VA cells using negative LC. The reason is related to low rotational viscosity of positive LC. When the liquid crystal in the VA-IPS cell is aligned along with the applied electric field, we exposed UV light. Photosensitive side chains underwent photo-dimerization, which vertically aligned liquid crystals with pre-tilted angle. Because the new photo-alignment layer can make pre-tilted liquid crystal without RM, It can improve contrast ratio and production of VA mode LCD.

목차 (Table of Contents)

• 제1장 서 론 1
• 제2장 이론 배경 3
• 2. 1. 액정 3
• 2. 1. 1. 액정의 정의 3
• 2. 1. 2. 액정의 종류 4
• 2. 2. 액정디스플레이(LCD) 7
• 2. 2. 1. 액정디스플레이의 동작원리 7
• 2. 2. 2. 수직배향(VA) 모드 액정디스플레이 10
• 2. 2. 3. VA-IPS소자의 구동원리 12
• 2. 3. 액정배향막 14
• 2. 3. 1. 액정배향막 14
• 2. 3. 2. 선경사각 17
• 2. 3. 3. VA 모드용 액정배향막(수직배향막) 19
• 2. 3. 4. 액정 광배향 20
• 2. 4. 폴리이미드 22
• 제 3장 실험 25
• 3. 1. 시약 25
• 3. 1. 1. HAB-6FDA Polyimide 25
• 3. 1. 2. DOBPEO 25
• 3. 1. 3. 4-HEC 25
• 3. 1. 4. PI-DO-C 26
• 3. 2. 측정 27
• 3. 3. 물질 합성 28
• 3. 3. 1. HAB-6FDA Polyimide 합성 28
• 3. 3. 2. 4’-(decyloxy)biphenyl-4-ol 합성 29
• 3. 3. 3. “DOBPEO”합성 30
• 3. 3. 4. “4-HEC”합성 31
• 3. 3. 5. “PI-DO30-C70”합성 32
• 3. 3. 6. “PI-DO50-C50”합성 33
• 3. 3. 7. “PI-DO70-C30”합성 34
• 3. 3. 8. “PI-DO90-C10”합성 35
• 3. 4. VA-IPS 소자 제작 36
• 3. 5. VA-IPS 소자의 선경사각 형성 37
• 제 4장 결과 및 논의 39
• 4. 1. HAB-6FDA PI, DOBPEO, 4-HEC 합성 결과 39
• 4. 1. 1. HAB-6FDA PI 합성 결과 39
• 4. 1. 2. DOBPEO 합성 결과 41
• 4. 1. 3. 4-HEC 합성 결과 43
• 4. 2. PI-DO-C Alignment Layer 합성 결과 45
• 4. 3. PI-DO-C Alignment Layer의 열 특성 49
• 4. 4. PI-DO-C Alignment Layer의 광 특성 53
• 4. 5. 4-HEC측쇄의 Photodimerization 특성 55
• 4. 6. PI-DO-C Alignment Layer의 VA-IPS 소자 특성 57
• 4. 6. 1. PI-DO-C(VA-IPS) 소자의 수직배향 특성 57
• 4. 6. 2. PI-DO-C(VA-IPS) 소자의 전압-투과도 특성 59
• 4. 6. 3. PI-DO-C(VA-IPS) 소자의 응답시간 특성 65
• 제 5장 결론 67
• 제 6장 참고문헌 69