화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
Polymer(Korea), Vol.44, No.6, 841-847, November, 2020
DOI10.7317/pk.2020.44.6.841  Export Citation
광개시제 종류에 따른 유기 박막의 경화 특성과 플렉서블 디스플레이 봉지 소재로의 적용성 분석
Effect of Photo-initiators on the Crosslinking Behavior of Organic Thin Films and Their Applicability to Flexible Display Encapsulation Layer
오준기, 김소현, 정인조, 허 준, 정현욱†, 방준하†
  • 고려대학교 화공생명공학과
Junki Oh, So Hyun Kim, Kevin Injoe Jung, June Huh, Hyun Wook Jung†, and Joona Bang†
  • Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Korea
E-mail:,
초록
플렉서블 디스플레이에 적용할 수 있는 유기 박막 개발을 위해 광경화성 소재에 대한 특성화를 진행하였다. 광경화에 필수적인 요소인 광개시제는 광 조사 시 분해되며 라디칼을 생성하는 Type-1 개시제와 분해없이 라디칼을 생성하는 Type-2 개시제 유형으로 구분된다. Type-2 개시제는 미반응물에 의한 아웃가스 배출이 거의 없는 특성으로 인해 디스플레이 봉지 유기층 제조에 결정적인 역할을 할 수 있다. 본 연구에서는 봉지층에 사용될 유기 코팅액의 경화물성을 최적화하기 위해 Type-1, Type-2 개시제에 의한 실시간 가교 물성을 비교 분석하였다. 잉크젯 코팅 공정으로의 적용 가능성을 평가하기 위하여 경화 이전 코팅액의 점도와 표면 장력 등과 같은 기본 유동 물성을 측정하였다. 또한 경화된 박막 필름의 투과율, 굴절률 등과 같은 광학적 물성들을 분석하였다. 다양한 실험 결과로부터 아웃가스 저배출 성능이 뛰어난 Type-2 개시제가 유기막의 핵심 성분으로 디스플레이 봉지 기술을 개발하는데 매우 유용함을 확인하였다.
In this work, we examined photocurable materials for organic layers that can be used as an encapsulation layer in flexible displays. Photo-initiators, which are essential for UV-crosslinking, can be classified into two categories: Type-1 initiators that produce free radicals through the cleavage reaction caused by UV irradiation and Type-2 initiators that generate free radicals without the cleavage reaction. Type-2 initiators are more desirable for the encapsulation organic layer of the flexible display due to the low outgassing of unreacted components. To optimize the curing properties of organic coatings, the effect of initiator type on the real-time crosslinking behaviors were mainly scrutinized. The flow properties of pre-cured coatings such as shear viscosity and surface tension were also measured to evaluate the applicability in the inkjet coating process, and transmittance and refractive index were analyzed for the optical properties of cured thin films. As a result, it was found that Type-2 initiators, exerting the intrinsic low outgassing performance, are more advantageous in developing the display encapsulation technology as a key component in the organic layer.
Keywords:photo-initiator;organic layer;encapsulation;outgas;flexible display
  1. Bae JW, Jung JH, Wang HS, Kim SH, Kim IJ, Kim IJ, Song K, Polym. Korea, 41(2), 361 (2017)
  2. Kim SH, Chang HS, Park S, Song K, Polym. Korea, 34(5), 469 (2010)
  3. Lee JR, Heo GY, Park SJ, Polym. Korea, 26(1), 80 (2002)
  4. Albini A, Fagnoni M, Green Chem., 6, 1 (2004)
  5. Protti S, Dondi D, Fagnoni M, Albini A, Pure Appl. Chem., 79, 1929 (2007)
  6. Yagci Y, Jockusch S, Turro NJ, Macromolecules, 43(15), 6245 (2010)
  7. Fouassier JP, Photoinitiation, Photopolymerization, and Photocuring: Fundamentals and Applications, Hanser, Munich, 1995.
  8. Davidson RS, Exploring the Science, Technology and Applications of UV and EB Curing, Sita Technology, London, 1999.
  9. Roffey CG, Photogeneration of Reactive Species for UV Curing, Wiley, Chichester, 1997.
  10. Kloosterboer JG, Adv. Polym. Sci., 84, 1 (1988)
  11. Yagci Y, Schnabel W, Macromol. Symp., 13, 161 (1988)
  12. Yagci Y, Reetz I, Prog. Polym. Sci, 23, 1485 (1998)
  13. Xiao P, Zhang J, Dumur F, Tehfe MA, Morlet-Savary F, Graff B, Gigmes D, Fouassier JP, Lalevee J, Prog. Polym. Sci, 41, 32 (2015)
  14. Shao JZ, Huang Y, Fan QU, Polym. Chem., 5, 4195 (2014)
  15. Laustriat G, Biochimie, 68, 771 (1986)
  16. Dadashi-Silab S, Aydogan C, Yagci Y, Polym. Chem., 6, 6595 (2015)
  17. Viswanathan K, Hoyle CE, Jonsson ES, Nason C, Lindgren K, Macromolecules, 35(21), 7963 (2002)
  18. Crawford GP, Flexible Flat Panel Display Technology, Wiley, Chichester, 2005.
  19. Burroughes JH, Bradley DD, Brown A, Marks R, Mackay K, Friend RH, Burns P, Holmes A, Nature, 347, 539 (1990)
  20. Gu G, Bulovic V, Burrows P, Forres S, Thompson M, Appl. Phys. Lett., 68, 2606 (1996)
  21. Burrows PE, Forrest SR, Thompson ME, Curr. opin. Solid State Mat. Sci., 2, 236 (1997)
  22. Kraft A, Grimsdale AC, Holmes AB, Angew. Chem.-Int. Edit., 37, 402 (1998)
  23. Kim S, Kwon HJ, Lee S, Shim H, Chun Y, Choi W, Kwack J, Han D, Song M, Kim S, Mohammadi S, Kee I, Lee SY, Adv. Mater., 23(31), 3511 (2011)
  24. Do L, Han E, Niidome Y, Fujihira M, Kanno T, Yoshida S, Maeda A, Ikushima A, J. Appl. Phys., 76, 5118 (1994)
  25. McElvain J, Antoniadis H, Hueschen M, Miller J, Roitman D, Sheats J, Moon R, J. Appl. Phys., 80, 6002 (1996)
  26. Sutherland D, Carlisle J, Elliker P, Fox G, Hagler T, Jimenez I, Lee H, Pakbaz K, Terminello L, Williams S, Appl. Phys. Lett., 68, 2046 (1996)
  27. Aziz H, Popovic Z, Tripp CP, Hu NX, Hor AM, Xu G, Appl. Phys. Lett., 72, 2642 (1998)
  28. Vetha BSS, Kim EM, Oh PS, Kim SH, Lim ST, Sohn MH, Jeong HJ, Macromol. Res., 27(12), 1179 (2019)
  29. Hong JS, Kwon HJ, Kim NH, Ye H, Baek YH, Park CE, Choe GO, An TK, Kim JY, Kim SH, Macromol. Res., 28(8), 782 (2020)
  30. Seok JH, Kim SH, Cho SM, Yi GR, Lee JY, Macromol. Res., 26(13), 1257 (2018)
  31. Langereis E, Creatore M, Heil S, Van de Sanden M, Kessels W, Appl. Phys. Lett., 89, 081915 (2006)
  32. Moro LL, et al., Organic Light-Emitting Materials and Devices VII, 5214, 83 (2004).
  33. Dameron AA, Davidson SD, Burton BB, Carcia PF, McLean RS, George SM, J. Phys. Chem., 112, 4573 (2008)
  34. Park S, Yun WM, Kim LH, Park S, Kim SH, Park CE, Org. Electron., 14, 3385 (2013)
  35. Xiao W, Yu D, Bo SF, Qiang YY, Dan Y, Ping C, Hui DY, Yi Z, RSC Adv., 4, 43850 (2014)
  36. Gabriel GJ, Som A, Madkour AE, Eren T, Tew GN, Mater. Sci. Eng. R-Rep., 57, 28 (2007)
  37. Wu J, Fei F, Wei C, Chen X, Nie S, Zhang D, Su W, Cui Z, RSC Adv., 8, 5721 (2018)
  38. Grego S, Lewis J, Vick E, Temple D, J. Soc. Inf. Disp., 13, 575 (2005)
  39. Affinito JD, Surf. Coat. Technol., 133, 528 (2000)