| 摘要 |
R-S1-A-Z1-B- S2-R, where A and B are independent ring systems with the formulae (a1), (a2) or (b), whereby in the trans-1,4-cyclohexylene ring, one or two non-adjacent CH2groups may be replaced by oxygen, and whereby, in the 1,4-phenylene ring, one or two non-adjacent CH groups may be replaced by nitrogen; L1, L2, L3represent, independently, hydrogen, C1-C20-alkyl, C1- C20-alkenyl, C1- C20-alkyloxy, C1-C 20-alkyloxy carbonyl, formyl, C1-C 20-alkyl carbonyl, C1-C20- alkyl carbonyloxy, halogen, cyano or nitro; Z1, Z2, Z3represent, independently, a single bond, -CH2CH2-, -CH2O-, -OCH2-, -COO-, -OOC-, -(CH2)4-, -O(CH2)3-, -(CH2)3O- or - C=C-; S1, S2represent a spacer unit, R represents crosslinkable groups, with the proviso that at least one of the ring systems A or B represents a ring system with the formulae (a1) or (a2), Z 1or Z2denoting a single bond. |
