| 摘要 |
Liquid crystalline phases characterized in that they have at least one compound of formula (I), wherein R<1> is an alkyl having between 1 and 12 atoms of carbon, one or two non adjacent CH2 groups which may be replaced by O atoms or -CO-, -O-CO-, -CO-O- and/or -CH=CH- groups, A<o> and A<1> represent independently from each other, Cy, Dio, Pyr or Phe, Z is -CO-O-, -O-CO-, -CH2-O-, -O-CH2- or a single bond, X<1> is F, Cl, -CN or -NCS, X<2> is F, Cl and in the case where X<1> = NCS, H<2> is also H, m is equal to 0 or 1, Cy is trans-1,4-cyclohexylene, Pyr is pyrimidine-2,5-diyle ou pyridine-2,5-diyl, Dio is trans-1,3-dioxane-2,5-diyl and Phe is 1,4-phenylen, and at least one compound having the formula (II), wherein R<2> is alkyl having between 1 and 12 atoms of carbon, one or two non adjacent CH2 groups which may be substituted by O atoms, -CO-, -O-CO-, -CO-O- and/or -CH=CH-; R<3> is alkyl having between 1 and 12 atoms of carbon, one or two non adjacent C2 groups which may be substituted by O atoms, -CO-, -O-CO-, -CO-O- and/or -CH=CH- groups, F, Cl or CN; A<2> and A<3> are Phe or Cy, n is equal to 0, 1 or 2 and Z, Dio, Phe and Cy have the meanings given hereabove. Said phases have particularly low threshold tensions. |
