Patent ID: 7125589

Claim:
A compound represented by the following formula (1): wherein Ra is alkyl having 1 to 15 carbons and any —CH 2 — in the alkyl may be replaced by —O—, —S—, —CH═CH—, or —C≡C—; A 1 , A 2 and A 3 independently are 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, decahydronaphthalene-2,6-diyl, 1,4-phenylene in which any hydrogen may be replaced by fluorine, naphthalene-2,6-diyl in which any hydrogen may be replaced by fluorine, or 1,2,3,4-tetrahydronaphthalene-2,6-diyl in which any —CH═ may be replaced by —CF═; Z 1 , Z 2 and Z 3 independently are a single bond, —(CH 2 ) 2 —, —(CF 2 ) 2 —, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 —, —CH═CH—, —CF═CF—, —C≡C—, —(CH 2 ) 4 —, —(CH 2 ) 3 O—, or —O(CH 2 ) 3 —; n and m independently are 0 or 1; phenyl having (F) p is phenyl, 2-fluorophenyl, 2,5-difluorophenyl, 2,3,5-trifluorophenyl, or 2,3,6-trifluorophenyl; with the proviso that when A 1 , A 2 and A 3 are 1,4-phenylene in which any hydrogen may be replaced by fluorine and Z 1 , Z 2 and Z 3 are a single bond, the total number of fluorine in formula (1) is at least two; and with the further proviso that the following compounds are excluded: wherein R is alkoxy or alkoxyalkoxy, and wherein R 1 is alkyl, either one of a 1 or a 2 is fluorine and the other thereof is hydrogen.