광분해성 고분자를 이용한 액정배향에서의 광조사 및 열처리 효과

이장주; 이원호; 신용일; 백상현; Jang-Ju Lee; Won-Ho Lee; Yong-Il Shin; Sang-Hyon Paek

Polymer(Korea), Vol.36, No.2, 145-148, March, 2012

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광분해성 고분자를 이용한 액정배향에서의 광조사 및 열처리 효과

Effects of UV Irradiation and Thermal Treatment of Photo-Degradable Polyimide Layer on LC Alignment

이장주, 이원호, 신용일, 백상현 ^†

경희대학교 공과대학 화학공학과

Jang-Ju Lee, Won-Ho Lee, Yong-Il Shin, and Sang-Hyon Paek^†

Department of Chemical Engineering, Kyung Hee University, 1 Seocheon-Dong, Giheung-gu, Yongin 449-701, Korea

E-mail:

초록

광분해형 CBDA-ODA 폴리이미드의 배향막에 대하여 선편광(LPUV) 조사와 이후의 열처리가 배향막, 액정 배향 그리고 LCD 특성에 어떠한 영향을 미치는지에 대하여 조사하였다. 가장 우수한 액정 배향은 배향막의 이방성을 최대로 발생시키는 광조사 에너지보다 상당히(약 5~10배) 작은 양의 광조사에 의하여 유도되었다. 광조사에 이후에 이어지는 배향막에 대한 열처리는 광분해 반응에 의하여 배향막 표면에 형성된 저분자 부산물들을 효과적으로 제거함과 동시에 광조사된 배향막을 안정화시킴으로써 액정의 배향성과 LCD의 전기적 특성을 향상시키는 결과를 가져왔다.

The effects of the linearly polarized UV (LPUV) irradiation and thermal treatment of a photo-degradable polyimide (CBDA-ODA) alignment layer (AL) on its AL properties, liquid crystal (LC) alignment, and LCD characteristics have been investigated. The best quality of LC photo-alignment have been induced by the LPUVirradiation with much (about 5~10 times) less dosage than that generating the maximum anisotropy of the AL. A thermal treatment of the LPUV-irradiated AL has effectively removed the undesirable, low-M.W. fragments of the AL generated during the photo-decomposition and increased the stability of the AL, which has resulted in improvement of the LC alignment and the LCD property.

Keywords:linear polarized UV irradiation;polyimide;photo-degradation;liquid crystal alignment;thermal treatment

[References]

Uchida T, Hirano M, Sakai H, Liquid Crystals., 5, 1127 (1989)
Dong W, Yi MH, Paek SH, Polym.(Korea), 27(5), 484 (2003)
Sakamoto K, Usami K, Ushioda S, J. Appl. Phys., 93(2), 1039 (2003)
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O’Neill M, Kelly SM, J. Phys. D: Appl. Phys., 33, 67 (2000)
Chigrinow V, Kozenkov V, Kwok HS, Photoalignment of Liquid Crystalline Materials: Physics and Application, Wiley-SID series (2008)
Lee JJ, Kim EJ, Paek SH, Mol. Cryst. Liq. Cryst., 539, 196 (2011)
Kawatsuki N, Koezuka Y, Polymer, 50(11), 2349 (2009)
Takatoh K, Hasegawa M, Koden M, Itoh N, Hasegawa R, Skamoto M, Alingment Technologies and Applications of Liquid Crystal Devices, Taylor & Francis, London and New York (2005)

[Related Articles]

[1] Uchida T, Hirano M, Sakai H, Liquid Crystals., 5, 1127 (1989)

[2] Dong W, Yi MH, Paek SH, Polym.(Korea), 27(5), 484 (2003)

[3] Sakamoto K, Usami K, Ushioda S, J. Appl. Phys., 93(2), 1039 (2003)

[4] Ha KR, West JL, J. Appl. Polym. Sci., 86(12), 3072 (2002)

[5] Hasegawa M, Taira Y, J. Photopoly. Sci. Technol., 8, 241 (1995)

[6] Sakamoto K, Usami K, Ushioda S, J. Appl. Phys., 33, 1435 (1999)

[7] O’Neill M, Kelly SM, J. Phys. D: Appl. Phys., 33, 67 (2000)

[8] Chigrinow V, Kozenkov V, Kwok HS, Photoalignment of Liquid Crystalline Materials: Physics and Application, Wiley-SID series (2008)

[9] Lee JJ, Kim EJ, Paek SH, Mol. Cryst. Liq. Cryst., 539, 196 (2011)

[10] Kawatsuki N, Koezuka Y, Polymer, 50(11), 2349 (2009)

[11] Takatoh K, Hasegawa M, Koden M, Itoh N, Hasegawa R, Skamoto M, Alingment Technologies and Applications of Liquid Crystal Devices, Taylor & Francis, London and New York (2005)