A method of preparing 2-bromo-4,6-dinitromesitylene having only small amounts of impurities, by first mixing fuming sulfuric acid with bromomesitylene, and then adding concentrated nitric acid.
一种制备仅含少量杂质的2-溴-4,6-二硝基间苯的方法,首先将浓硫酸与溴间苯混合,然后加入浓硝酸。
Liquid crystal displays of high tilt bias angles
申请人:E.I. DU PONT DE NEMOURS AND COMPANY
公开号:EP0507293A2
公开(公告)日:1992-10-07
Liquid Crystal Display Devices having alignment layers of polyimides which are characterized by pendant perfluorinated chains, preferably linear, and having more than 6 perfluorinated carbon atoms. These alignment layers are capable to provide the Liquid Crystal Display Devices with stable tilt angles of 5 or more degrees.