| 摘要 |
<p>PURPOSE:To produce a purified liq. crystal which gives a liq. crystal cell having improved voltage retention, long-term display stability, etc., by treating a liq. crystal with a powder of an imide compd. CONSTITUTION:A liq. crystal (e.g. a Schiff base, azo, or biphenyl liq. crystal) is purified by treating it with a powder of an imide compd. [e.g. a powder of a polyimide of formula I (wherein A<3> is a group of formula II or III; Z is -CH2-, -O-, -SO2-, -S-, etc.; and A<4> is a group of formula IV or V, etc.) obtd. by reacting a tetracarboxylic dianhydride with a diamine or diisocyanate]. Thus, the liq. crystal is sufficiently purified by using only a small amt. of the powder, giving a purified liq. crystal which has a greatly improved resistivity and gives a liq. crystal cell having a greatly improved voltage retention.</p> |
