Nematic liquid crystal composition and liquid crystal display device using same

1. A composition comprising

a compound represented by general formula (i) shown below,

a compound represented by general formula (ii) shown below, and

a compound represented by general formula (M) shown below:

wherein each of X i1 to X i6 independently represents a hydrogen atom, a fluorine atom or a chlorine atom, in which at least one of X i1 to X i6 is a fluorine atom, and each of X ii1 to X ii4 independently represents a hydrogen atom, a fluorine atom or a chlorine atom, in which at least one of X ii1 to X ii4 is a fluorine atom; and

wherein R M1 represents an alkyl group of 1 to 8 carbon atoms, and one —CH 2 — group or two or more non-adjacent —CH 2 — groups within the alkyl group may each be independently substituted with —CH═CH—, —C≡C—, —O—, —CO—, —COO— or —OCO—,

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

each of C M1 and C M2 independently represents a group selected from the group consisting of:

(d) a 1,4-cyclohexylene group (wherein one —CH 2 — group or two or more non-adjacent —CH 2 — groups that exist within this group may each be substituted with —O— or —S—), and

(e) a 1,4-phenylene group (wherein one —CH═ group or two or more non-adjacent —CH═ groups that exist within this group may each be substituted with —N═),

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

each of K M1 and K M2 independently represents a single bond, —CH 2 CH 2 —, —(CH 2 ) 4 —, —OCH 2 —, —CH 2 O—, —OCF 2 —, —CF 2 O—, —COO—, —OCO— or —CC—,

when PM represents 2, 3 or 4 and a plurality of K M1 exists, the K M1 may be identical or different, when PM represents 2, 3 or 4 and a plurality of C M2 exists, the C M2 may be identical or different,

each of X M1 and X M3 independently represents a hydrogen atom, a chlorine atom or a fluorine atom, and

X M2 represents fluorine atom, chlorine atom, cyano group, trifluoromethyl group, fluoromethoxy group, difluoromethoxy group, trifluoromethoxy group or 2,2,2-trifluoroethyl group,

wherein at least one of the compound represented by the general formula (M) in which at least one of K M1 and K M2 is —CF 2 O— is included in the composition; and

compounds represented by the general formula 26.2 and 45.2:

2. The composition according to claim 1 , wherein an amount of the compound represented by general formula (i) is at least 3% by mass, and an amount of the compound represented by general formula (ii) is at least 3% by mass.

3. The composition according to claim 1 , further comprising a compound represented by general formula (L) shown below:

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

wherein each of R L1 and R L2 independently represents an alkyl group of 1 to 8 carbon atoms, and one —CH 2 — group or two or more non-adjacent —CH 2 — groups within the alkyl group may each be independently substituted with —CH═CH—, —C≡C—, —O—, —CO—, —COO— or —OCO—,

OL represents 0, 1, 2 or 3,

each of B L1 , B L2 and B L3 independently represents a group selected from the group consisting of:

(a) a 1,4-cyclohexylene group (wherein one —CH 2 — group or two or more non-adjacent —CH 2 — groups that exist within this group may each be substituted with —O—), and

(b) a 1,4-phenylene group (wherein one —CH═ group or two or more non-adjacent —CH═ groups that exist within this group may each be substituted with —N═),

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

each of L L1 and L L2 independently represents 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 represents 2 or 3 and a plurality of L L2 exists, the L L2 may be identical or different, and when OL represents 2 or 3 and a plurality of B L3 exists, the B L3 may be identical or different,

provided that the compound represented by general formula (L) excludes compounds represented by general formula (i) and compounds represented by general formula (ii).

4. A liquid crystal display device which uses the composition according to claim 1 .

5. An IPS device which uses the composition according to claim 1 .

6. An FFS device which uses the composition according to claim 1 .

7. The composition according to claim 1 , wherein an amount of the compound represented by general formula (i) is 3 to 30% by mass with respect to the total amount of the composition.

8. The composition according to claim 1 , wherein an amount of the compound represented by general formula (ii) is 3 to 30% by mass with respect to the total amount of the composition.

9. The composition according to claim 1 , wherein the composition is free of polymerizable compounds except for optionally a compound represented by general formula (XX) shown below:

wherein, each of X 201 and X 202 independently represents a hydrogen atom or a methyl group, each of Sp 201 and S p202 independently represents a single bond, an alkylene group of 1 to 8 carbon atoms, or —O—(CH 2 ) s — (wherein s represents an integer of 2 to 7, and the oxygen atom is bonded to the aromatic ring), Z 201 represents —OCH 2 —, —CH 2 O—, —COO—, —OCO—, —CF 2 O—, —OCF 2 —, —CH 2 CH 2 —, —CF 2 CF 2 —, —CH═CH—COO—, —CH═CH—OCO—, —COO—CH═CH—, —OCO—CH═CH—, —COO—CH 2 CH 2 —, —OCO—CH 2 CH 2 —, —CH 2 CH 2 —COO—, —CH 2 CH 2 —OCO—, —COO—CH 2 —, —OCO—CH 2 —, —CH 2 —COO—, —CH 2 —OCO—, —CY 1 ═CY 2 — (wherein each of Y 1 and Y 2 independently represents a fluorine atom or a hydrogen atom), —C═C—, or a single bond, M 201 represents a 1,4-phenylene group, a tran-1,4-cyclohexylene group or a single bond, and in all of the 1,4-phenylene groups within the formula, any arbitrary hydrogen atom may be substituted with a fluorine atom.

10. The composition according to claim 1 , wherein at least one of X i1 , X i2 , X i5 and X i6 of the compound represented by general formula (i) represents a fluorine atom, and at least one of X ii1 and X ii2 of the compound represented by general formula (ii) represents a fluorine atom.