聚酰亚胺制备条件对液晶预倾角的影响  

Effect of Polyimide Manufacturing Conditions on Pretilt Angle of Liquid Crystal

作　　者：白星[1] 王宇[1] 汪映寒[1] 

机构地区：[1]四川大学高分子科学与工程学院高分子材料工程国家重点实验室,四川成都610065

出　　处：《液晶与显示》2007年第3期268-272,共5页Chinese Journal of Liquid Crystals and Displays

基　　金：四川大学科技创新基金(No.2005CFOP)

摘　　要：液晶取向层性能优劣直接影响液晶分子在基板表面的排列效果,进而影响液晶显示器的光电性能,因此是制造液晶显示器的关键材料之一。文献大多研究聚酰亚胺结构对液晶预倾角的影响,而加料顺序对预倾角影响的研究,迄今还未引起注意。文章用均苯四酸二酐(PMDA)、4,4′-二胺基二苯甲烷(MDA)和具有较大支链的4-(4-(三氟甲氧基)苯甲酰基)环己基-3,5-二胺基苯甲酸酯(TBCA)等单体制备聚酰亚胺(PI),首次研究了单体加料顺序对液晶预倾角的影响,同时也研究了二胺配比对液晶预倾角的影响问题,并探讨了预倾角的热稳定性等问题。实验发现:先将PMDA加入TBCA的NMP溶液中,待PMDA完全溶解后,再加入MDA继续反应2 h,可得到预倾角为4.1°的聚酰亚胺液晶取向剂,且液晶盒在120℃下保持4 h后预倾角没有明显变化,预倾角稳定性良好。Liquid crystal （LC） alignment layer influences the alignment behavior of LC molecules on glass substrate, and thus affects the electro-optic properties of liquid crystal display （LCD）, so it is one of the key materials of manufacturing LCD. The effect of polyimide structure on LC pretilt angle has been investigated widely, but to our knowledge, the effect of monomer charge order on pretilt angle has not been explored. In this paper, 4-（4-（trifluoromethoxy）benzoyl）cyclohexyl-3, 5-diaminobenzoate （TBCA） with a large branch chain, pyromellitic dianhydride （PMDA） and 4-（4-aminobenzyl） benzenamine （MDA） were used to synthesize polyimides （PIs）. The effect of monomer charge order on pretilt angle was investigated for the first time when PIs were used as LC alignment layer, and the effect of diamine mole ratio on pretilt angle was studied. The thermal stability of the pretilt angle was discussed. The result was concluded as follows： PMDA was firstly added to NMP solution of TBCA, and then MDA was added to the mixture when PMDA was dissolved completely. The reaction lasted for 2 h. In this condition, a pretilt angle as high as 4. 1 ° was induced. The pretilt angle did not change obviously when the LC cell was kept at 120 ℃ for 4 h, and its thermal stability is good.

关 键 词：液晶 聚酰亚胺 制备条件 单体加料顺序 预倾角 

分 类 号：O753.2[理学—晶体学]