Liquid crystal composition and liquid crystal display device using the same

1. A liquid crystal composition comprising:

at least two compounds selected from the group consisting of compounds represented by general formula (1):

In general formula (1), n is an integer greater than 1 and less than 6, m is an integer greater than 1 and less than 6, and n is less than or equal to m;

at least one compound selected from the group consisting of compounds represented by general formula (2):

In general formula (2), R 1 and R 2 each independently represent an alkyl group having 1 to 15 carbon atoms;

at least one compound selected from the group consisting of compounds represented by general formula (3):

In general formula (3), R 3 and R 4 each independently represent a group selected from the group consisting an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, and an alkoxy group having 1 to 15 carbon atoms;

at least one compound selected from the group consisting of compounds represented by general formula (VI-a-1):

In general formula (VI-a-1), R 6a and R 6b each independently represent an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms; and

a compound represented by general formula (5.1) below:

wherein 5 to 35% by mass of a compound represented by general formula (1) is contained.

2. The composition according to claim 1 , further comprising:

at least one compound selected from the group consisting of compounds represented by general formula (4):

in general formula (4), R 5 and R 6 each independently represent one selected from the group consisting of an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, and an alkoxy group having 1 to 15 carbon atoms; however, the compounds represented by general formula (1) are excluded from the compounds represented by general formula (4).

3. The composition according to claim 1 , wherein R 3 represents an alkyl group having 1 to 15 carbon atoms and R 4 represents an alkoxy group having 1 to 15 carbon atoms.

4. The liquid crystal composition according to claim 1 , further comprising:

at least one compound selected from the group of compounds represented by general formula (5):

R L1 —B L1 -L L1 -B L2 L L2 -B L3 )— OL R L2   (5)

In general formula (5), R L1 and R L2 each independently represent an alkyl group having 1 to 8 carbon atoms, one —CH 2 — or two or more nonadjacent —CH 2 — in the alkyl group may each independently be substituted with —CH═CH—, —O—, —CO—, —COO—, or —OCO—,

OL represents 0, 1, 2, or 3,

B L1 , B L2 , and B L3 each independently represent a group selected from the group consisting of (a) and (b) below:

(a) a 1,4-cyclohexylene group one —CH 2 — or two or more nonadjacent —CH 2 — present in this group may be substituted with —O—

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

hydrogen atoms in the groups (a) and (b) above may each independently be substituted with a cyano group, a chlorine atom, or a fluorine atom,

L L1 and L L2 each independently represent 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

when OL is 2 or 3 and two or more L L2 are present, they may be the same or different and when OL is 2 or 3 and two or more B L3 are present, they may be the same or different provided that compounds represented by general formula (1), compounds represented by general formula (2), compounds represented by general formula (3), compounds represented by general formula (VI-a-1), and compounds represented by general formula (5.1) are excluded from the compounds represented by general formula (5).

5. The liquid crystal composition according to claim 1 , further comprising:

at least one compound selected from the group consisting of compounds represented by general formula (6):

In general formula (6), R X1 and R X2 each independently represent an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, one methylene group or two or more nonadjacent methylene groups present in these groups may each be substituted with —O— or —S—, and one or more hydrogen atoms present in these groups may each be substituted with a chlorine atom and/or a fluorine atom;

u and v each independently represent 0, 1, or 2 where u+v is 2 or less;

M X1 , M X2 and M X3 each independently represent one selected from the group consisting of (a) and (b) below:

(a) a trans-1,4-cyclohexylene group one methylene group or two or more nonadjacent methylene groups present in this group may be substituted with —O— or —S—

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

hydrogen atoms contained in the group (a) or (b) may each be substituted with a group selected from the group consisting of a cyano group, a fluorine atom, a trifluoromethyl group, and a trifluoromethoxy group, and when two or more M X2 and/or M X3 are present, they may be the same or different;

L X1 , L X2 , and L X3 each independently represent a single bond, —COO—, —OCO—, —CH 2 CH 2 —, —(CH 2 ) 4 —, —OCH 2 —, —CH 2 O—, —OCF 2 —, —CF 2 O—, —CH═CH—, or —C≡C—, and when two or more L X1 and/or L X3 are present, they may be the same or different,

X X1 and X x2 each independently represent a trifluoromethyl group, a trifluoromethoxy group, or a fluorine atom and one of X 31 and X 32 represents a fluorine atom; however, compounds represented by general formula (1) compounds represented by general formula (2), compounds represented by general formula (3), compounds represented by general formula (VI-a-1), and compounds represented by general formula (5.1) are excluded from the compounds represented by general formula (6).

6. The liquid crystal composition according to claim 1 , further comprising a polymerizable monomer.

7. A liquid crystal display device that uses the liquid crystal composition according to claim 1 .

8. A liquid crystal display comprising the liquid crystal display device according to claim 7 .

9. A liquid crystal display device that uses the liquid crystal composition according to claim 3 .