PURPOSE: To enable liq. crystal display of high quality by applying a composition contg. specified polyamic acid to the liq. crystal sides of substrates each having a transparent electrode film, and causing the ring closure of the polyamic acid by dehydration to form polyimide films.
CONSTITUTION: Biphenyltetracarboxylic acid anhydride is brought into reaction with diamine such as m-phenylenediamine in a solvent to produce polyamic acid. The resulting composition contg. polyamic acid is applied to the liq. crystal sides of substrates each having a transparent electrode film, and by heating the substrates, the ring closure of the polyamic acid is caused by dehydration to form polyimide films. Thus, the desired substrates for holding a liq. crystal are obtd. The polyimide films used as orienting films are slightly colored, and they have superior adhesive properties to the substrates and superior orientation controlling power for keeping a liq. crystal in a homogeneously oriented state. The orientation controlling power is not deprived by heat treatment.
UCHIMURA SHIYUNICHIROU
SATOU TOUNOBU
MAKINO DAISUKE
UCHIGASAKI ISAO
