液晶显示用取向材料聚甲基丙烯酸肉桂酰氧基乙酯的光控取向研究

通过实验研究了光聚合物材料聚甲基丙烯酸肉桂酰氧基乙酯（ＣＥＭＣ）的光化学反应过程， 以及对液晶材料ＬＣ－６７１０Ａ 的取向能力． 通过原子力显微镜（ＡＦＭ）观察了取向层表面在光化学反应前后的变化， 测量了光控取向膜液晶盒中液晶分子的预倾角及单面光控取向扭曲向列液晶显示器（ＴＮＬＣＤ）的电光特性和时间响应特性曲线， 研究了液晶分子排列取向的机理．

STUDY ON PHOTO ALIGNMENT OF CINNAMATE MATERIAL 2 (CINNAMOYLOXY)ETHYL METHACRYLATE FOR LCD USING LPP METHOD BY UV LIGHT

Surface alignment of liquid crystals (LCs) on treated polymer substrates is one of key technologies to fabricate liquid crystal displays(LCDs) and thus many works on this subject have been done. Recent process of photo alignment control of LC molecules on photopolymer film was considered the photo alignment technique is a hopeful candidate for rubbing free technique. The process of photochemical reaction of Cinnamate material 2 (cinnamoyloxy)ethyl methacrylate (CEMC) using LPP(linear polarized photopolymerization) method by UV light was studied in this paper. We also investigated the effect of the CEMC aligning on liquid crystal LC 6710A molecules. The liquid crystal molecules alignment was more homogeneous when the photosensitive IRG184 was taken a part into pre polymer CEMC mixture. The photochemical reaction probability was increased because of the energy transfer between photosensitive IRG184 and pre photopolymer CEMC molecules. The change of alignment substrate surface, which was shown less difference on the micrography of substrate surface was observed before and after photochemical reaction by Atomic Force Microscopy (AFM). The pretilt angle 0 7 degree of LC molecules on photo alignment substrate surface was measured. The electro optical property and time response curves of twisted nematic liquid crystal display (TNLCD) with single side photo alignment substrate were obtained. It is shown that the properties curves of TNLCD with single side photo alignment substrate and conventional TNLCD were similar. The mechanism of liquid crystal molecule alignment on photo alignment substrate surface was discussed. We consider that the liquid crystal molecules alignment was not ascribed to the grooves on the substrate surface, but was ascribed to the interaction between liquid crystal molecules and photopolymer molecules on substrate surface. The photopolymer material CEMC is feasible for LCD fabrication.