Liquid crystal composition and liquid display device

1 . A liquid crystal composition comprising at least one compound of general formula I-1, at least two compounds of general formula II and at least two compounds of general formula III:

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 2 -R 5 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl, C 1-12 alkoxy, C 2-12 alkenyl, C 2-12 alkenoxy,

 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 one or at least two single bond in at least one ring

 is replaced by double bond;

ring

 each independently represents

 one or at least two —H on

 can each be independently replaced by —F, —Cl, —CN, —CH 3 or —OCH 3 , one or at least two —CH═ in the rings can be replaced by —N═;

L 1 -L 6 each independently represents halogen atom;

X 1 and X 2 each independently represents —O— or —S—;

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

 is the same or different; and

n 3 represents 0, 1, 2 or 3, n 4 represents 0 or 1, and 2≤n 3 +n 4 ≤3; when n 3 represents 2 or 3, ring

 is the same or different;

in the liquid crystal composition, percentage by weight of the at least one compound of general formula I-1 is 1%-20%;

in the liquid crystal composition, percentage by weight of the at least two compounds of general formula II is 15%-36%;

in the liquid crystal composition, percentage by weight of the at least two compounds of general formula III is 3%-15%;

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

 each independently represents

 wherein one or at least two —CH 2 — in

 can be replaced by —O—; 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;

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

 is the same or different, and Z N1 is the same or different; and

substituted or unsubstituted terphenyl structure is not contained in the compound of general formula N, the substituent for substitution is selected from —F, —Cl or —CN;

in the liquid crystal composition, percentage by weight of the at least one compound of general formula N is 5%-25%;

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

 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; 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 —;

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

 is the same or different, Z M2 is the same or different;

in the liquid crystal composition, percentage by weight of the at least one compound of general formula M is 30%-50%.

2 . The liquid crystal composition according to claim 1 , wherein L 1 and L 2 represent fluorine atom.

3 . The liquid crystal composition according to claim 1 , wherein the liquid crystal composition comprises at least two compounds of general formula I-1.

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

5 . The liquid crystal composition according to claim 1 , wherein the at least two compounds of general formula II are selected from the group consisting of:

wherein R 2 and R 3 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl, C 1-12 alkoxy, C 2-12 alkenyl, C 2-12 alkenoxy,

 and

wherein L 3 and L 4 each independently represents halogen atom.

6 . The liquid crystal composition according to claim 1 , wherein L 3 and L 4 both represent fluorine atom.

7 . The liquid crystal composition according to claim 1 , wherein the at least two compounds of general formula III are selected from the group consisting of:

wherein R 4 and R 5 each independently represents C 1-12 linear alkyl, C 3-12 branched alkyl, C 1-12 alkoxy, C 2-12 alkenyl, C 2-12 alkenoxy,

 and

wherein L 5 and L 6 each independently represents halogen atom.

8 . The liquid crystal composition according to claim 1 , wherein L 5 and L 6 both represent fluorine atom.

9 . The liquid crystal composition according to claim 1 , wherein the at least one compound of general formula N is selected from the group consisting of:

wherein, R N1 and R N2 each independently represents C 1-2 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—.

10 . The liquid crystal composition according to claim 9 , wherein the at least one compound of general formula N is selected from the group consisting of:

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—.

11 . The liquid crystal composition according to claim 1 , wherein the at least one compound of general formula M is selected from the group consisting of:

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—.

12 . The liquid crystal composition according to claim 11 , wherein the at least one compound of general formula M is selected from the group consisting of:

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—.

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

wherein:

R B1 and R B2 each independently represents halogen atom, C 1-12 halogenated or unhalogenated linear alkyl, C 3-12 halogenated or unhalogenated branched alkyl,

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

 can each independently be replaced by —CH═CH—, —C≡C—, —CH═CF—, —O—, —CO—, —CO—O— or —O—CO—;

ring

 each independently represents

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

X B represents —O—, —S— or —CO—;

L B1 and L B2 each independently represents —H, —F, —Cl, —CF 3 or —OCF 3 ;

Z B1 and Z B2 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 )n B4 -, —(CH 2 )n B4 O—, —(CH 2 )n B4 S—, —CF 2 O— or —OCF 2 —, wherein n B4 represents an integer of 0-5; and

n B1 and n B2 each independently represents 0, 1 or 2, wherein when n B1 represents 2, ring

 is the same or different, when n B2 represents 2, ring

 is the same or different, Z B2 is the same or different.

14 . The liquid crystal composition according to claim 13 , wherein the at least one compound of general formula B is selected from the group consisting of:

wherein:

R B1 ′ represents C 1-8 alkyl, C 1-8 alkoxy, C 2-8 alkenyl;

X B1 represents —O— or —CH 2 —;

R B2 represents halogen atom, C 1-12 halogenated or unhalogenated linear alkyl, C 3-12 halogenated or unhalogenated branched alkyl,

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

 can each independently be replaced by —CH═CH—, —C≡C—, —CH═CF—, —O—, —CO—, —CO—O— or —O—CO—;

X B represents —O—, —S— or —CO—;

Z B1 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 )n B4 -, —(CH 2 )n B4 O—, —(CH 2 )n B4 S—, —CF 2 O— or —OCF 2 —; and

n B4 represents an integer of 0-5.

15 . The liquid crystal composition according to claim 14 , wherein the at least one compound of general formula B-1 is selected from the group consisting of:

wherein:

R B2 ′ represents C 1-8 alkyl;

R B1 ′ represents C 1-8 alkyl, C 1-8 alkoxy or C 2-8 alkenyl;

X B represents —O—, —S— or —CO—;

n B3 represents 1, 2, 3 or 4; and

n B5 represents 0, 1, 2, 3 or 4.

16 . The liquid crystal composition according to claim 13 , wherein, in the liquid crystal composition, percentage by weight of the at least one compound of general formula B is 1%-10%.

17 . A liquid crystal display device, wherein the liquid crystal display device comprises the liquid crystal composition of claim 1 .