Difluorobenzene derivative and nematic liquid crystal composition using the same

1. A nematic liquid crystal composition, comprising:

10 to 80% by mass of either one or at least two compounds represented by general formula (I) as a first component:

(wherein R 1 represents an alkenyl group of 2 to 10 carbon atoms, in which one CH 2 group, or at least two CH 2 groups that are not adjacent, may be substituted with O and/or S, and one or at least two hydrogen atoms may be substituted with F or Cl; R 2 represents an alkenyl group of 2 to 10 carbon atoms or an alkenyloxy group of 3 to 10 carbon atoms; and m represents 0, 1, or 2); and

20 to 70% by mass of either one or at least two compounds represented by general formula (II) as a second component:

(wherein R 3 and R 4 each represent, independently, an alkyl group of 1 to 10 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, an alkenyl group of 2 to 10 carbon atoms, or an alkenyloxy group of 3 to 10 carbon atoms;

B 1 and B 2 each represent, independently, a group selected from the group consisting of

(a) a trans-1,4-cyclohexylene group (in which one CH 2 group, or at least two CH 2 groups that are not adjacent, may be substituted with an oxygen atom or a sulfur atom),

(b) a 1,4-phenylene group (in which one or at least two CH groups may be substituted with a nitrogen atom), and

(c) a 1,4-cyclohexenylene group, a 1,4-bicyclo[2.2.2]octylene group, a piperidine-1,4-diyl group, a naphthalene-2,6-diyl group, a decahydronaphthalene-2,6-diyl group, and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group,

in which a hydrogen atom of the above group (a), group (b), or group (c) may be substituted with CN or halogen;

Y 1 and Y 2 each represent, independently, —CH 2 CH 2 —, —CH═CH—, —CH(CH 3 )CH 2 —, —CH 2 CH(CH 3 )—, —CH(CH 3 )CH(CH 3 )—, —CF 2 CF 2 —, —CF═CF—, —CH 2 O—, —OCH 2 —, —OCH(CH 3 )—, —CH(CH 3 )O—, —(CH 2 ) 4 —, —(CH 2 ) 3 O—, —O(CH 2 ) 3 —, —C≡C—, —CF 2 O—, —OCF 2 —, —COO—, —OCO—, —COS—, —SCO—, or a single bond;

in the case where pluralities of Y 2 and B 2 exist, a plurality of Y 2 or B 2 may be the same or different;

and

p represents 0, 1, or 2), wherein

a dielectric constant anisotropy is negative.

2. The nematic liquid crystal composition according to claim 1 , wherein at least one of R 3 and R 4 represents an alkenyl group in said general formula (II).

3. The nematic liquid crystal composition according to claim 1 , comprising either one or at least two compounds selected from the group consisting of compounds represented by general formula (I-A) and general formula (I-B):

(wherein R 5 and R 7 each represent, independently, an alkenyl group of 2 to 10 carbon atoms, and R 6 and R 8 each represent, independently, an alkenyl group of 3 to 10 carbon atoms).

4. The nematic liquid crystal composition according to claim 1 , comprising either one or at least two compounds selected from the group consisting of compounds represented by general formula (II-A) through general formula (II-G):

(wherein R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 , R 21 , R 22 , R 23 , R 24 , R 25 and R 26 each represent, independently, an alkyl group of 1 to 10 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, an alkenyl group of 2 to 10 carbon atoms, or an alkenyloxy group of 3 to 10 carbon atoms).

5. The nematic liquid crystal composition according to claim 4 , comprising:

either one or at least two compounds selected from the group consisting of compounds represented by general formula (I-A) and general formula (I-B):

(wherein R 5 and R 7 each represent, independently, an alkenyl group of 2 to 10 carbon atoms, and R 6 and R 8 each represent, independently, an alkenyl group of 3 to 10 carbon atoms); and

a compound represented by said general formula (II-A), general formula (II-C), or general formula (II-D).

6. The nematic liquid crystal composition according to claim 2 , comprising either one or at least two compounds selected from the group consisting of compounds represented by general formula (II-A-1) through general formula (II-A-8):

(wherein R 9 , R 10 , and R 11 each represent, independently, an alkyl group of 1 to 10 carbon atoms or an alkoxy group of 1 to 10 carbon atoms).

7. The nematic liquid crystal composition according to claim 2 , comprising either one or at least two compounds selected from the group consisting of compounds represented by general formula (II-B-1) through general formula (II-B-7):

(wherein R 12 , R 13 , R 14 , R 15 , R 16 , and R 17 , each represent, independently, an alkyl group of 1 to 10 carbon atoms or an alkoxy group of 1 to 10 carbon atoms).

8. The nematic liquid crystal composition according to claim 2 , comprising either one or at least two compounds selected from the group consisting of compounds represented by general formula (II-C-1) through general formula (II-C-6):

(wherein R 21 and R 22 each represent, independently, an alkyl group of 1 to 10 carbon atoms or an alkoxy group of 1 to 10 carbon atoms).

9. The nematic liquid crystal composition according to claim 2 , comprising either one or at least two compounds selected from the group consisting of compounds represented by general formula (II-D-1) through general formula (II-D-5):

(wherein R 27 and R 28 each represent, independently, an alkyl group of 1 to 10 carbon atoms or an alkoxy group of 1 to 10 carbon atoms).

10. The nematic liquid crystal composition according to claim 6 , comprising:

either one or at least two compounds selected from the group consisting of compounds represented by said general formula (I-A) and general formula (I-B); and

a compound represented by said general formula (II-A-1), general formula (II-A-2), or general formula (II-A-3).

11. The nematic liquid crystal composition according to claim 8 , comprising:

either one or at least two compounds selected from the group consisting of compounds represented by said general formula (I-A) and general formula (I-B); and

a compound represented by said general formula (II-C-1), general formula (II-C-2), or general formula (II-C-4).

12. The nematic liquid crystal composition according to claim 1 , further comprising either one or at least two compounds selected from the group consisting of compounds represented by general formula (III-A) through general formula (III-J):

(wherein R 29 and R 30 each represent, independently, an alkyl group of 1 to 10 carbon atoms or an alkenyl group of 2 to 10 carbon atoms, in which one CH 2 group, or at least two CH 2 groups that are not adjacent, may be substituted with O and/or S, and one or at least two hydrogen atoms may be substituted with F or Cl; and

R 31 represents an alkyl group of 1 to 10 carbon atoms, in which one CH 2 group, or at least two CH 2 groups that are not adjacent, may be substituted with O and/or S, and one or at least two hydrogen atoms may be substituted with F or Cl).

13. The nematic liquid crystal composition according to claim 1 , wherein a dielectric constant anisotropy Δ∈ at 25° C. is within a range of −2.0 to −8.0, a refractive index anisotropy Δn at 25° C. is within a range of 0.06 to 0.16, a viscosity at 20° C. is within a range of 10 mPa·s to 30 mPa·s, and a nematic phase-isotropic liquid phase transition temperature Tni is within a range of 70° C. to 130° C.

14. A liquid crystal display element, which uses a nematic liquid crystal composition according to claim 1 .

15. A liquid crystal display element for active matrix driving, which uses a nematic liquid crystal composition according to claim 1 .

16. A liquid crystal display element for VA mode, IPS mode, or ECB mode, which uses a nematic liquid crystal composition according to claim 1 .