| 摘要 |
<p>A non-smectic liquid crystal mixt. consists of >=2 components. The first, polar component contains >=1 polar end gp and has a +ve anisotropic dielectric constant. The second, non-polar component contains 2 non-polar end-gps. The non-polar component, together with the polar component, can form a stable, smectic and/or solid phase in a limited mixing range. The proportion of the polar component in the mixt. is so small that the smectic or solid phase is not yet present. A pref. non-polar component is a cpd. having formula (I): (where M and M' are -N=N-, -CH=CH-, -CH=CCl-, -N=N(O)-, -CH=N-, -C=C-, -COO- or -COS-, and either M and M' can be omitted. X and Y are alkyloxy, alkyl, alkanoyl, alkanoyloxy or alkoxycarbonyloxy gps.). The polar component differs from the non-polar component in that one of X and Y is replaced by -CN, -NO2 or -Cl.</p> |
