Liquid crystal composition and liquid crystal display device

1 . A liquid crystal composition comprising at least one compound of general formula I-1 and at least one compound selected from general formula II-1 and general formula II-2:

wherein, R 1 represents —H, C 1-12 halogenated or unhalogenated linear alkyl, C 3-12 halogenated or unhalogenated branched alkyl, C 1-12 halogenated or unhalogenated alkoxy, C 2-12 halogenated or unhalogenated alkenyl, C 2-12 halogenated or unhalogenated alkenoxy,

R 21 and R 32 each independently represents C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl, or C 2-12 alkenoxy;

R 22 represents halogen atom, C 1-5 halogenated alkyl, C 1-5 halogenated alkoxy, C 2-5 halogenated alkenyl, or C 2-5 halogenated alkenoxy;

R 31 represents —H, C 1-12 alkyl, or C 1-12 alkoxy;

ring

represents

ring

ring

ring

and ring

each independently represents

one or at least two —CH 2 — in

can be replaced by —O—, one or at least two single bond in the rings can be replaced by double bond, and at least one single bond in the rings in at least one of ring

and ring

is replaced by double bond, at least one single bond in the rings in at least one of ring

and ring

is replaced by double bond;

L 1 and L 2 represent fluorine atom;

X 1 represents —O—;

X 2 represents —O— or —S—;

n 2 represents 0, 1, 2, 3 or 4;

percentage by weight of the compound of general formula I-1 is 0.1%-20%;

percentage by weight of the compound of general formula II-1 is 0.1%-20%;

percentage by weight of the compound of general formula II-2 is 0.1%-20%;

the liquid crystal composition further comprises at least one compound of general formula III:

wherein, R 2 represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl, C 3-12 branched alkyl,

can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—, and one or at least two-H in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —F or —Cl;

Z 2 represents single bond, —CH 2 CH 2 —, —CF 2 CF 2 —, —CO—O—, —O—CO—, —O—CO—O—, —CH═CH—, —CF═CF—, —CH 2 O— or —OCH 2 —;

X 3 represents —O— or —CH 2 —;

X 4 represents —F or —H; and

X 5 represents halogen atom, C 1-5 halogenated alkyl, C 1-5 halogenated alkoxy, C 2-5 halogenated alkenyl, or C 2-5 halogenated alkenoxy;

percentage by weight of the compound of general formula III is 0.1%-20%;

the liquid crystal composition further comprises a group of compounds consisting of at least one compound of general formula A-1 and at least one compound of general formula A-2:

wherein, R A1 and R A2 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein, one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl, C 3-12 branched alkyl,

can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—, and one or at least two-H in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —F or —Cl;

ring

represents

wherein one or at least two —CH 2 — in

can be replaced by —O—; one or at least two single bond in the rings in

can be replaced by double bond; one or at least two —H on

can each be independently replaced by —F, —Cl or —CN, one or at least two —CH═ in the rings can be replaced by —N═;

ring

represents

wherein one or at least two —CH 2 — in

can be replaced by —O—, one or at least two single bond in the rings can be replaced by double bond; one or at least two —H on

can each be independently replaced by —F, —Cl or —CN, one or at least two —CH═ in the rings can be replaced by —N═;

ring

each independently represents

wherein one or at least two —CH 2 — in

can be replaced by —O—, one or at least two single bond in the rings in

can be replaced by double bond; one or at least two —H on

can each be independently replaced by —F, —Cl or —CN, one or at least two —CH═ in the rings can be replaced by —N═;

Z A11 , Z A21 and Z A22 each independently represents single bond, —CH 2 CH 2 —, —CF 2 CF 2 —, —CO—O—, —O—CO—, —O—CO—O—, —CH—CH—, —CF═CF—, —CH 2 O— or —OCH 2 —;

L A11 , L A12 , L A13 , L A21 and L A22 each independently represents —H, C 1-3 alkyl, or halogen atom;

X A1 and X A2 each independently represents halogen atom, C 1-5 halogenated alkyl, C 1-5 halogenated alkoxy, C 2-5 halogenated alkenyl or C 2-5 halogenated alkenoxy;

n A11 represents 0, 1, 2 or 3, wherein when n A11 represents 2 or 3, ring

can be the same or different, and Z A11 can be the same or different;

n A12 represents 1 or 2, wherein when n A12 represents 2, ring

can be the same or different; and

n A2 represents 0, 1, 2 or 3, wherein when n A2 represents 2 or 3, ring

can be the same or different, and Z A21 can be the same or different;

percentage by weight of the compound of general formula A-1 is 0.1%-20%;

in the liquid crystal composition, percentage by weight of the compound of general formula A-2 is 0.1%-20%;

the liquid crystal composition further comprises at least one compound of general formula M:

wherein, R M1 and R M2 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—;

ring

ring

and ring

each independently represents

wherein one or at least two —CH 2 — in

can be replaced by —O—; at most one —H on

can be replaced by halogen atom;

Z M1 and Z M2 each independently represents single bond, —CO—O—, —O—CO—, —CH 2 O—, —OCH 2 —, —C≡C—, —CH═CH—, —CH 2 CH 2 — or —(CH 2 ) 4 —; and

n M represents 0, 1 or 2, wherein when n M represents 2, ring

can be the same or different, Z M2 can be the same or different;

in the liquid crystal composition, percentage by weight of the compound of general formula Mis 20%-80%.

2 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula I-1 is 1%-10%.

3 . The liquid crystal composition according to claim 1 , wherein the compound of general formula II-1 is any one of the compounds with the following structures:

wherein,

R 21 represents C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl, or C 2-12 alkenoxy;

R 31 represents —H, C 1-12 alkyl, or C 1-12 alkoxy; and

n 2 represents 0, 1, 2, 3 or 4.

4 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula II-1 is 1%-10%.

5 . The liquid crystal composition according to claim 1 , wherein the compound of general formula II-2 is any one of the compounds with the following structures:

wherein,

R 22 represents halogen atom, C 1-5 halogenated alkyl, C 1-5 halogenated alkoxy, C 2-5 halogenated alkenyl, or C 2-5 halogenated alkenoxy; and

R 32 represents C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl, or C 2-12 alkenoxy.

6 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula II-2 is 1%-10%.

7 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, sum of percentages by weight of the compounds of general formula II-1 and general formula II-2 is 0.1%-30%.

8 . The liquid crystal composition according to claim 7 , wherein, in the liquid crystal composition, sum of percentages by weight of the compounds of general formula II-1 and general formula II-2 is 1%-15%.

9 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula III is 5%-15%.

10 . The liquid crystal composition according to claim 1 , wherein the liquid crystal composition further comprises at least one compound of general formula N:

wherein, R N1 and R N2 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—;

ring

and ring

each independently represents

wherein one or at least two —CH 2 — in

can be replaced by —O—, one or at least two single bond in the rings can be replaced by double bond; one or at least two —H on

can each be independently replaced by —F, —Cl or —CN, one or at least two —CH═ in the rings can be replaced by —N═;

Z N1 and Z N2 each independently represents single bond, —CO—O—, —O—CO—, —CH 2 O—, —OCH 2 —, —CH═CH—, —C≡C—, —CH 2 CH 2 —, —CF 2 CF 2 —, —(CH 2 ) 4 —, —CF 2 O— or —OCF 2 —;

L N1 and L N2 each independently represents —H, C 1-3 alkyl, or halogen atom; and

n N1 represents 0, 1, 2 or 3, n N2 represents 0 or 1, and 0≤n N1 +n N2 ≤3, wherein when n N1 represents 2 or 3, ring

can be the same or different, and Z N1 can be the same or different.

11 . The liquid crystal composition according to claim 10 , wherein the compound of general formula N is any one of the compounds with the following structures:

wherein, R N1 and R N2 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—.

12 . The liquid crystal composition according to claim 10 , wherein the compound of general formula N is any one of the compounds with the following structures:

wherein, R N1 and R N2 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—.

13 . The liquid crystal composition according to claim 10 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula N is 0.1%-20%.

14 . The liquid crystal composition according to claim 13 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula Nis 2%-15%.

15 . The liquid crystal composition according to claim 1 , wherein the compound of general formula A-1 is any one of the compounds with the following structures:

wherein, R A1 represents C 1-8 linear alkyl, C 3-8 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-8 linear alkyl and C 3-8 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—, and one or at least two —H in the C 1-8 linear alkyl and C 3-8 branched alkyl can each be independently replaced by —F or —Cl;

R v and R w each independently represents —CH 2 — and —O—;

v and w each independently represents 0 or 1;

L A11 , L A12 , L A11 ′, L A12 ′, L A14 , L A15 and L A16 each independently represents —H or —F;

L A13 and L A13 ′ each independently represents —H or —CH 3 ; and

X A1 represents —F, —CF 3 or —OCF 3 .

16 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula A-1 is 4%-15%.

17 . The liquid crystal composition according to claim 1 , wherein the compound of general formula A-2 is any one of the compounds with the following structures:

wherein, R A2 represents C 1-8 linear alkyl, C 3-8 branched alkyl, wherein one or at least two nonadjacent —CH 2 — in the C 1-8 linear alkyl and C 3-8 branched alkyl can each be independently replaced by —CH—CH—, —C═C—, —O—, —CO—, —CO—O— or —O—CO—, and one or at least two —H in the C 1-8 linear alkyl and C 3-8 branched alkyl can each be independently replaced by —F or —Cl;

L A21 , L A22 , L A23 , L A24 and L A25 each independently represents —H or —F; and

X A2 represents —F, —CF 3 , —OCF 3 or —CH 2 CH 2 CH═CF 2 .

18 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula A-2 is 1%-10%.

19 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, sum of percentages by weight of the compound of general formula A-1 and the compound of general formula A-2 is 0.1%-30%.

20 . The liquid crystal composition according to claim 1 , wherein the compound of general formula M is any one of the compounds with the following structures:

wherein, R M1 and R M2 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—.

21 . The liquid crystal composition according to claim 1 , wherein the compound of general formula M is any one of the compounds with the following structures:

wherein, R M1 and R M2 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl,

wherein one or at least two nonadjacent —CH 2 — in the C 1-12 linear alkyl and C 3-12 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—.

22 . The liquid crystal composition according to claim 1 , wherein, in the liquid crystal composition, percentage by weight of the compound of general formula Mis 40%-68%.

23 . A liquid crystal display device, wherein the liquid crystal display device comprises the liquid crystal composition of claim 11 .