Abstract

As a model of polymer-sustained-alignment liquid crystal display (PSA-LCD), the LC cells having the PSA layers formed from mixed monomers of 2,7-dimethacryloyl-oxy-phenanthrene (2,7-DMAPhen) and 4,4′-dimethacryloyl-oxy-benzilketal (4,4′-DMABzk) were fabricated and investigated image sticking phenomenon with evaluations of residual direct current voltage (V _rDC) and difference in pretilt angle (Δtilt) before and after application of alternate current voltage. A rate constant of the polymerization became large with an addition of a small amount of 4,4′-DMABzk into 2,7-DMAPhen. The V _rDC was effectively improved with the addition of a small amount of 4,4′-DMABzk because the concentrations of radical and/or ion in the LC layer were decreased due to enlargement of the rate constant of the polymerization. The Δtilt was small enough only below 9.1 wt% of 4,4′-DMABzk in the mixed monomers of 2,7-DMAPhen and 4,4′-DMABzk. We confirmed that the PSA-LC cell formed from the mixed monomers of 2,7-DMAPhen and 4,4′-DMABzk with the weight ratio of 4,4′-DMABzk between 3.8 wt% and 9.1 wt% was useful for obtaining the low level of image sticking.

摘要

作为聚合物维持取向液晶显示器（PSA-LCD）的模型，具有由2,7-二甲基丙烯酰基-氧-菲（2,7-DMAPhen）和4,4的混合单体形成的PSA层的LC单元制备了'-二甲基丙烯酰氧基-苯甲酮（4,4'-DMABzk），并通过评估残留直流电压（V _rDC）和施加交流电压前后的预倾角差（Δtilt）来研究图像残留现象。通过向2，7-DMAPhen中添加少量的4,4'-DMABzk，聚合的速率常数变大。该V _RDC通过添加少量的4,4'-DMABzk有效地改善了聚合反应，因为由于聚合速率常数的增大，LC层中自由基和/或离子的浓度降低了。在2，7-DMAPhen和4，4′-DMABzk的混合单体中，Δtilt足够小，仅低于9.1wt％的4，4′-DMABzk。我们证实，由2,7-DMAPhen和4,4'-DMABzk的混合单体形成的PSA-LC电池，其4,4'-DMABzk的重量比在3.8 wt％和9.1 wt％之间，对于获得图像残留水平低。