Liquid crystal composition and application thereof

1. A liquid crystal composition, wherein the liquid crystal composition comprises:

at least one compound of general formula I

and

at least one compound selected from a group consisting of the compounds of general formula II-1 and general formula II-2

in which,

R 1 , R 2 , R 3 , R 4 , R 3 ′ and R 4 ′ each independently represents —H, —F, C 1-12 alkyl or alkoxy,

C 2-12 alkenyl or alkenoxy, —OR 5 OR 6 ,

wherein one or more H on the alkyl or alkoxy and the alkenyl or alkenoxy can be substituted by F, and at least one of R 1 and R 2 is —OR 5 OR 6 ;

R 6 represents C 1-12 alkyl or C 2-12 alkenyl;

R 5 is —C 3 H 6 — or —C 4 H 8 —;

Z 1 , Z 2 and Z 3 each independently represents single bond, —COO—, —OCO—, —CH 2 O—, —OCH 2 — or —CH 2 CH 2 —;

L 1 and L 2 each independently represents —F, —Cl, —CN or —NCS;

ring

and ring

each independently represents

wherein one or more —CH 2 — in

can be replaced by —O—, one or more H on

can be substituted by halogen;

ring

ring

ring

ring

and ring

each independently represents

n1 and n2 each independently represents 0, 1, 2 or 3, and when n1 is 2 or 3, ring

can be same or different, Z 1 can be same or different; when n2 is 2 or 3, ring

can be same or different, Z 2 can be same or different;

m represents 1 or 2, and when m is 2, ring

can be same or different, Z 3 can be same or different.

2. The liquid crystal composition according to claim 1 , wherein the compound of general formula I is selected from a group consisting of the following compounds:

in which,

ring

represents

and when n1 is 1, ring

represents

when n1 is 2 or 3, at least one ring

represents

L 6 , L 7 , L 8 and L 9 each independently represents —H or —F;

o represents 1 or 2;

p and q each independently represents 0 or 1.

3. The liquid crystal composition according to claim 2 , wherein the compound of general formula I-1 is selected from a group consisting of the following compounds:

the compound of general formula I-2 is selected from a group consisting of the following compounds:

in which,

R 11 and R 21 each independently represents —H, —F, C 1-7 alkyl or alkoxy, C 2-7 alkenyl or alkenoxy, —OR 51 OR 61 ,

wherein one or more H on the alkyl or alkoxy and the alkenyl or alkenoxy can be substituted by F, and at least one of R 11 and R 21 is —OR 51 OR 61 ;

R 51 is —C 3 H 6 — or —C 4 H 8 —, and R 61 represents C 1-10 alkyl or C 2-10 alkenyl.

4. The liquid crystal composition according to claim 1 , wherein the compound of general formula II-1 is selected from a group consisting of the following compounds:

the compound of general formula II-2 is selected from a group consisting of the following compounds:

in which,

R 31 , R 41 , R 31 ′ and R 41 ′ each independently represents H, C 1-7 alkyl or alkoxy, or C 2-7 alkenyl or alkenoxy.

5. The liquid crystal composition according to claim 1 , wherein the liquid crystal composition at least comprises more than 2 wt % of the compound of general formula II-2.

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

in which,

R 7 and R 8 each independently represents —H, —F, C 1-12 alkyl or alkoxy, C 2-12 alkenyl or alkenoxy,

wherein one or more H on the alkyl or alkoxy and the alkenyl or alkenoxy can be substituted by F;

Z 4 and Z 5 each independently represents single bond, —COO—, —OCO—, —CH 2 O—, —OCH 2 — or —CH 2 CH 2 —;

ring

and ring

each independently represents

wherein one or more —CH 2 — in

can be replaced by —O—, one or more H on

on can be substituted by halogen;

k1 and k2 each independently represents 0, 1, 2 or 3, and when k1 is 2 or 3, ring

can be same or different, Z 4 can be same or different; when k2 is 2 or 3, ring

can be same or different, Z 5 can be same or different.

7. The liquid crystal composition according to claim 6 , wherein the compound of general formula I provides 1 to 60% of the total weight of the liquid crystal composition, the compound selected from a group consisting of the compounds of general formula II-1 and general formula II-2 provides 1 to 55% of the total weight of the liquid crystal composition, and the compound of general formula III provides 0 to 60% of the total weight of the liquid crystal composition.

8. The liquid crystal composition according to claim 7 , wherein the compound of general formula I provides 1 to 50% of the total weight of the liquid crystal composition, the compound selected from a group consisting of the compounds of general formula II-1 and general formula II-2 provides 1 to 55% of the total weight of the liquid crystal composition, and the compound of general formula III provides 0 to 55% of the total weight of the liquid crystal composition.

9. A liquid crystal display device comprising the liquid crystal composition of claim 1 .