Liquid crystal composition having high-speed response property and liquid crystal display using the same

1. A nematic liquid crystal composition comprising a nematic liquid crystal compound represented by the following Chemical Formula 5:

Chemical Formula 5

wherein: R is C n H 2n+1 O, C n H 2n+1 , or C n H 2n−1 , wherein n is an integer of 1 to 15; R′ is

or

here R 1 is H or F; L is an integer of 0 to 2; B is —C≡C—; each of X and Y is H, F, Cl, or Br, independently or simultaneously; and at least one of X and Y is F.

2. The nematic liquid crystal composition according to claim 1 , which comprises:

a) 1 to 80 wt % of the nematic liquid crystal compound represented by Chemical Formula 5; and

b) 20 to 99 wt % of one or more liquid crystal compounds selected from a group consisting of the compounds represented by the following Chemical Formula 2, Chemical Formula 3, and Chemical Formula 4:

Chemical Formula 2

R 2 —A 1 —B 1 —X 1

Chemical Formula 3

Chemical Formula 4

wherein:

each of R 2 is C n H 2n+1 or C n H 2n , independently or simultaneously, wherein n is an integer of 1 to 15,;

each of A 1 and B 1 is ,

or

independently or simultaneously;

X 1 is F, CF 3 , OCF 3 , CH═CF 2 , or OCH═CF 2 ;

each of A 2 is

or

independently or simultaneously; and each of A 3 , B 2 , and C is F, CF 3 , OCF 3 , or H, independently or simultaneously.

3. A nematic liquid crystal composition comprising a nematic liquid crystal compound represented by the following Chemical Formula 6:

Chemical Formula 6

wherein: R is C n H 2n+1 O, C n H 2n+1 , C n H 2n+1 S, or C n H 2n−1 , wherein n is an integer of 1 to 15; A is phenyl, phenyl-cyclohexane, cyclohexane-phenyl, or a single bond (—); L is 0 or 1; B is —C≡C—; X is H, F, Cl, or Br; Y is NCS, SCN, or F; Z is H, F, Cl, or Br; at least one of X and Z is F; and at least one of A and B is not a single bond.

4. The nematic liquid crystal composition according to claim 3 , which comprises:

a) 1 to 80 wt % of the nematic liquid crystal compound represented by Chemical Formula 6; and

b) 20 to 99 wt % of one or more liquid crystal compounds selected from a group consisting of the compounds represented by the following Chemical Formula 2, Chemical Formula 3, and Chemical Formula 4:

Chemical Formula 2

R 2 —A 1 —B 1 —X 1

Chemical Formula 3

Chemical Formula 4

wherein:

each of R 2 is C n H 2n+1 , or C n H 2n , independently or simultaneously, wherein n is an integer of 1 to 15;

each of A 1 and B 1 is

or

independently or simultaneously;

X 1 is F, CF 3 , OCF 3 , CH═CF 2 , or OCH═CF 2 ;

each of A 2 is

independently or simultaneously; and

each of A 3 , B 2 and C is F, CF 3 , OCF 3 , or H, independently or simultaneously.

5. A nematic liquid crystal composition comprising a nematic liquid crystal compound represented by the following Chemical Formula 7:

Chemical Formula 7

wherein:

R 1 is a C 1 to C 12 alkyl, wherein one or two separated CH 2 groups can be substituted by an oxygen atom, —CO—, —OCO—, —COO—, or —C═C— group;

each of A 0 and A 1 is

independently or simultaneously;

each of X 1 and X 2 is F, Cl, CN, or NCS, independently or simultaneously; and 1 is 1.

6. The nematic liquid crystal composition according to claim 5 , which comprises:

a) 20 to 80 wt % of the nematic liquid crystal compound represented by Chemical Formula 7; and

b) 20 to 80 wt % of a nematic liquid crystal compound represented by the following Chemical Formula 8:

Chemical Formula 8

wherein:

R 3 is a C 1 to C 12 alkyl; wherein one or two separated CH 2 groups can be substituted by an oxygen atom, —CO—, —OCO—, —COO—, or —C═C— group;

each of A 4 and A 5 is

independently or simultaneously;

each of X 5 and X 6 is F, Cl, CN, or NCS, independently or simultaneously; and

n is 0 or 1.

7. The nematic liquid crystal composition according to claim 5 , which further comprises:

c) one or more compounds selected from a group consisting of the nematic liquid crystal compounds represented by the following Chemical Formula 10 and Chemical Formula 11:

Chemical Formula 10

wherein:

R 6 is a C 1 to C 12 alkyl;

or

X 7 is H, F, Cl, or OCH 3 ; and

each of X 8 and X 9 is H, F, or Cl, independently or simultaneously; and

Chemical Formula 11

wherein:

R 7 is a C 1 to C 12 alkyl;

A 8 is

or

and

each of X 14 , X 15 and X 13 is H, F, or Cl, independently or simultaneously.

8. A liquid crystal display comprising the nematic liquid crystal composition according to claim 1 .

9. The liquid crystal display according to claim 8 , which is an active matrix type TN (twist nematic), STN, OCB, TFT-TN mode liquid crystal display, or an IPS (in plane switching) mode or FFS (fringe field switching) mode liquid crystal display.

10. The liquid crystal display according to claim 8 , which is an AOC or COA liquid crystal display, or an OCB (optically compensated bend) mode liquid crystal display.

11. A liquid crystal display comprising the nematic liquid crystal composition according to claim 3 .

12. The liquid crystal display according to claim 11 , which is an active matrix type TN (twist nematic), STN, OCB, TFT-TN mode liquid crystal display, or an IPS (in plane switching) mode or FFS (fringe field switching) mode liquid crystal display.

13. The liquid crystal display according to claim 11 , which is an AOC or COA liquid crystal display, or an OCB (optically compensated bend) mode liquid crystal display.

14. A liquid crystal display comprising the nematic liquid crystal composition according to claim 5 .

15. The liquid crystal display according to claim 14 , which is an active matrix type TN (twist nematic), STN, OCB, TFT-TN mode liquid crystal display, or an IPS (in plane switching) mode or FFS (fringe field switching) mode liquid crystal display.

16. The liquid crystal display according to claim 14 , which is an AOC or COA liquid crystal display, or an OCB (optically compensated bend) mode liquid crystal display.

17. A nematic liquid crystal composition, comprising:

a nematic liquid crystal compound represented by the following Chemical Formula 7:

Chemical Formula 7

wherein:

R 1 is a C 1 to C 12 alkyl, wherein one or two separated CH 2 groups can be substituted by a compound or compounds selected from the group consisting of a oxygen atom, —CO—, —OCO—, —COO—, and —C═C— group;

each of A 0 and A 1 is selected from the group consisting of

independently or simultaneously;

each of X 1 X 2 is F, Cl, CN, or NCS, independently or simultaneously;

1 is 0 or 1; and

one or more compounds selected from a group consisting of the nematic liquid crystal compounds represented by the following Chemical Formula 9:

Chemical Formula 9

wherein:

R 4 is a C 1 C 12 alkyl, and R 5 is a C 1 to C 12 alkyl or alkoxy; and

A 6 is

18. A liquid crystal display comprising the nematic liquid crystal composition of claim 17 .

19. The liquid crystal display of claim 18 , wherein the LCD has a mode selected from the group consisting of an active matrix type TN (twist nematic), a STN, an OCB, a TFT-TN, an IPS (in plane switching) and a FFS (fringe field switching).

20. The liquid crystal display of claim 18 , wherein the LCD had a mode selected from the group consisting of an AOC, COA, and an OCB (optically compensated birefringence).

21. The nematic liquid crystal composition of claim 17 , wherein the composition had a refractive index anisotropy in a range of about 0.07 to about 0.1.

22. The nematic liquid crystal composition of claim 17 , wherein the composition is in a nematic phase at a temperature in a range of about −20° C. to about 80° C.

23. The nematic liquid crystal composition of claim 17 , wherein the composition has an electric resistance greater than about 10 12 Ωcm.

24. The nematic liquid crystal composition of claim 17 , wherein the composition has a threshold voltage in a range of about 1.5 to about 2.0 V which is defined by the following equation

V

th

=

π

⁢

K

ɛ

0

⁢

Δ

⁢

⁢

ɛ

Equation

⁢

⁢

1

wherein V th is the threshold voltage, Δ∈ is the dielectric constant, anisotropy, and K is the modulus of elasticity.

25. The liquid crystal display of claim 18 , wherein the LCD has a response time less than about 10 ms.