Liquid Crystal Composition and Liquid Crystal Display Device

• US 20110062384A1
• Filed: 08/24/2010
• Published: 03/17/2011
• Est. Priority Date: 09/15/2009
• Status: Active Grant

• Current Assignee: JNC Petrochemical Corporation (Chisso Corporation)
• Original Assignee: Chisso Corporation, Chisso Petrochemical Corporation
• Inventors: SAITO, Masayuki, HIRAOKA, Takashi, YANAI, Takayoshi
• Granted Patent: US 8,057,867 B2
• Time in Patent Office: Days
• US Class Current: 252/299.61
• CPC Class Codes: C09K 19/126 Compounds containing at least one asymmetric carbon atom
• CPC Class Codes: C09K 19/3003 Compounds containing at least two rings in which the different rings are directly linked (covalent bond)
• CPC Class Codes: C09K 19/3068 chain containing -COO- or -OCO- groups
• CPC Class Codes: C09K 19/44 containing compounds with benzene rings directly linked
• CPC Class Codes: C09K 2019/123 Ph-Ph-Ph
• CPC Class Codes: C09K 2019/301 Cy-Cy-Ph
• CPC Class Codes: C09K 2019/3016 Cy-Ph-Ph
• CPC Class Codes: C09K 2019/3075 Cy-COO-Ph
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition

Abstract

Subject The subject is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large elastic constant ratio, a small temperature dependence of the threshold voltage, a small frequency dependence of the dielectric anisotropy and a short helical pitch, or that is suitably balanced regarding at least two of the characteristics. The subject is to provide a STN device that has a short response time, a large contrast ratio, a low threshold voltage, a small electric power consumption, a steep voltage-transmission curve and a small light leak.

Means for Solving the Subject The invention provides a nematic liquid crystal composition that include a specific optically active compound as a first component and a specific compound having a positively large dielectric anisotropy as a second component, and that optionally may include a specific compound having a high maximum temperature or a small viscosity as a third component and a specific compound having a positively large dielectric anisotropy as a fourth component, and provides a liquid crystal display device containing this composition.

Claims

1. A liquid crystal composition that has a nematic phase and comprises two components, wherein a first component is at least one optically active compound selected from the group of compounds represented by formula (1), and a second component is at least one compound selected from the group of compounds represented by formula (2):

2. The liquid crystal composition according to claim 1, wherein the sum of the number of carbons of R² and R³ in formula (1) is an integer from 3 to 10.

3. The liquid crystal composition according to claim 2, wherein the first component is at least one compound selected from the group of compounds represented by formula (1-1) to formula (1-3):

4. The liquid crystal composition according to claim 1, wherein the ratio of the first component is in the range of approximately 0.01 part to approximately 5 parts by weight based on 100 parts by weight of the liquid crystal composition excluding the first component.

5. The liquid crystal composition according to claim 1, wherein the second component is at least one compound selected from the group of compounds represented by formula (2-1) to formula (2-7):

6. The liquid crystal composition according to claim 1, wherein the ratio of the second component is in the range of approximately 5% to approximately 70% by weight based on the weight of the liquid crystal composition excluding the first component.

7. The liquid crystal composition according to claim 1, further comprising at least one compound selected from the group of compounds represented by formula (3) as a third component:

8. The liquid crystal composition according to claim 7, wherein the third component is at least one compound selected from the group of compounds represented by formula (3-1) to formula (3-17):

9. The liquid crystal composition according to claim 7, wherein the ratio of the third component is in the range of approximately 30% to approximately 95% by weight based on the weight of the liquid crystal composition excluding the first component.

10. The liquid crystal composition according to claim 1, further comprising at least one compound selected from the group of compounds represented by formula (4) as a fourth component:

11. The liquid crystal composition according to claim 7, further comprising at least one compound selected from the group of compounds represented by formula (4) as a fourth component:

12. The liquid crystal composition according to claim 10, wherein the fourth component is at least one compound selected from the group of compounds represented by formula (4-1) to formula (4-6):

13. The liquid crystal composition according to claim 11, wherein the fourth component is at least one compound selected from the group of compounds represented by formula (4-1) to formula (4-6):

14. The liquid crystal composition according to claim 10, wherein the ratio of the fourth component is in the range of approximately 5% to approximately 50% by weight based on the weight of the liquid crystal composition excluding the first component.

15. The liquid crystal composition according to claim 11, wherein the ratio of the fourth component is in the range of approximately 5% to approximately 50% by weight based on the weight of the liquid crystal composition excluding the first component.

16. A liquid crystal display device containing the liquid crystal composition according to claim 1.