Liquid crystal composition and liquid crystal display element containing the same

1. A liquid crystal composition comprising:

at least one compound represented by a general formula (i);

at least one compound represented by a general formula (ii),

a compound represented by a general formula (X),

43% to 70% by mass of a compound represented by general formula (I-1), and

15% to 35% by mass of a compound represented by general formula (II-2),

(wherein in the general formula (i), R i1 denotes an alkyl group having 2 to 5 carbon atoms),

(wherein in the general formula (ii), R ii1 and R ii2 independently denote an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and X ii1 and x ii2 independently denote a hydrogen atom or a fluorine atom),

(wherein in the general formula (X), X 101 to X 104 independently denote a fluorine atom or a hydrogen atom, Y 10 denotes a fluorine atom, a chlorine atom, or —OCF 3 , Q 10 denotes a single bond or —CF 2 O—, R 10 denotes an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and A 101 and A 102 independently denote a 1,4-cyclohexylene group, a 1,4-phenylene group, or one of

in which A 101 is

in which a hydrogen atom of the 1,4-phenylene group may be substituted with a fluorine atom),

(wherein in the general formula (I-1), R 11 and R 12 independently denote an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms),

(wherein in the general formula (II-2), R 23 denotes an alkenyl group having 2 to 5 carbon atoms, and R 24 denotes an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 4 carbon atoms).

2. The liquid crystal composition according to claim 1 , further comprising at least one compound represented by a general formula (L),

(wherein R L1 and R L2 independently denote an alkyl group having 1 to 8 carbon atoms, and one or two or more nonadjacent —CH 2 — of the alkyl group may be independently substituted with —CH═CH—, —C≡C—, —O—, —CO—, —COO—, or —OCO—,

OL is 0, 1, 2, or 3,

B L1 , B L2 , and B L3 independently denote a group selected from the group consisting of

(a) a 1,4-cyclohexylene group (one —CH2- or two or more nonadjacent —CH2- of this group may be substituted with —O—), and

(b) a 1,4-phenylene group (one —CH═ or two or more nonadjacent —CH═ of this group may be substituted with —N═),

the group (a) and the group (b) may be independently substituted with a cyano group, a fluorine atom, or a chlorine atom,

L L1 and L L2 independently denote a single bond, —CH 2 CH 2 —, —(CH 2 ) 4 —, —OCH 2 —, —CH 2 O—, —COO—, —OCO—, —OCF 2 —, —CF 2 O—, —CH═N—N═CH—, —CH═CH—, —CF═CF—, or —C≡C—, and

in the case that OL is 2 or 3 and there are a plurality of LL2s, the plurality of LL2s may be the same or different, and in the case that OL is 2 or 3 and there are a plurality of B L3 s, the plurality of B L3 s may be the same or different, provided that the at least one compound is not the compound(s) selected from a group represented by the general formula (ii)).

3. The liquid crystal composition according to claim 1 or 2 , further comprising at least one compound represented by a general formula (M),

(wherein R M1 denotes an alkyl group having 1 to 8 carbon atoms, and one or two or more nonadjacent —CH2- of the alkyl group may be independently substituted with —CH═CH—, —C≡C—, —O—, —CO—, —COO—, or —OCO—,

PM is 0, 1, 2, 3, or 4,

C M1 and CM M2 independently denote a group selected from the group consisting of

(d) a 1,4-cyclohexylene group (one —CH2- or two or more nonadjacent —CH2- of this group may be substituted with —O— or —S—), and

(e) a 1,4-phenylene group (one —CH═ or two or more nonadjacent —CH═ of this group may be substituted with —N═),

the group (d) and the group (e) may be independently substituted with a cyano group, a fluorine atom, or a chlorine atom,

K M1 and K M2 independently denote a single bond, —CH 2 CH 2 —, —(CH 2 ) 4 —, —OCH 2 —, —CH 2 O—, —OCF 2 —, —CF 2 O—, —COO—, —OCO—, or —C≡C—,

in the case that PM is 2, 3, or 4 and there are a plurality of K M1 s, the plurality of K M1 s may be the same or different, and in the case that PM is 2, 3, or 4 and there are a plurality of CM2s, the plurality of CM2s may be the same or different,

X M1 and X M3 independently denote a hydrogen atom, a chlorine atom, or a fluorine atom, and

X M2 denotes a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a fluoromethoxy group, a difluoromethoxy group, a trifluoromethoxy group, or a 2,2,2-trifluoroethyl group, the at least one compound being not the compound(s) represented by the general formula (i)).

4. The liquid crystal composition according to claim 1 , comprising at least one compound represented by a general formula (IV-1) as a compound or compounds represented by the general formula (ii),

(wherein R 43 and R 44 independently denote an alkyl group having 1 to 5 carbon atoms).

5. The liquid crystal composition according to claim 2 , comprising a compound represented by a general formula (I-1-1) as a compound represented by the general formula (L), the compound represented by the general formula (I-1-1) constituting 14% or more,

(wherein R 12 denotes an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms).

6. The liquid crystal composition according to claim 2 , comprising a compound represented by a general formula (II-2) as a compound represented by the general formula (L), the compound represented by the general formula (II-2) constituting 5% or more,

(R 23 denotes an alkenyl group having 2 to 5 carbon atoms, and R 24 denotes an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 4 carbon atoms).

7. The liquid crystal composition according to claim 1 , comprising a compound represented by a general formula (IV-2) as a compound represented by the general formula (ii),

(wherein R 45 and R 46 independently denote an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, at least one of R 45 and R 46 denotes an alkenyl group having 2 to 5 carbon atoms, and X 41 and X 42 independently denote a hydrogen atom or a fluorine atom).

8. The liquid crystal composition according to claim 3 , comprising a compound represented by a general formula (X-6) as a compound represented by the general formula (M), the compound represented by the general formula (X-6) constituting 0.5% or more and less than 5%,

(wherein R 10 denotes an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms).

9. The liquid crystal composition according to claim 8 , comprising a compound represented by a formula (44.1) as a compound represented by the general formula (X-6), the compound represented by the formula (44.1) constituting 0.5% or more and less than 5%,

10. The liquid crystal composition according to claim 2 , comprising a compound represented by a general formula (III) as a compound represented by the general formula (L), the compound represented by the general formula (III) constituting 6% or more,

(R 31 and R 32 independently denote an alkenyl group having 2 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms).

11. A liquid crystal display element for active-matrix driving, comprising the liquid crystal composition according to claim 1 .