LIQUID CRYSTAL COMPOSITION AND LIQUID CRYSTAL DISPLAY APPARATUS USING THE SAME

• US 20080273160A1
• Filed: 03/26/2008
• Published: 11/06/2008
• Est. Priority Date: 05/02/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Oh, Keun-Chan, Son, Jong-Ho, Kim, Hyun-Wuk
• Granted Patent: US 7,695,778 B2
• Time in Patent Office: Days
• US Class Current: 349/182
• 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 19/44 containing compounds with benzene rings directly linked
• CPC Class Codes: C09K 2019/0407 containing a carbocyclic ring, e.g. dicyano-benzene, chlorofluoro-benzene or cyclohexanone
• CPC Class Codes: C09K 2019/123 Ph-Ph-Ph
• CPC Class Codes: C09K 2019/3004 Cy-Cy
• CPC Class Codes: C09K 2019/3009 Cy-Ph
• CPC Class Codes: C09K 2019/301 Cy-Cy-Ph
• CPC Class Codes: C09K 2019/3016 Cy-Ph-Ph
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: G02F 1/0045 Liquid crystals characterised by their physical properties
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence

Abstract

A liquid crystal composition includes a bicyclohexyl compound in an amount of about 35 percent by weight to about 50 percent by weight, a cyclohexyl phenyl compound in an amount of about 15 percent by weight to about 25 percent by weight, a bicyclohexyl phenyl compound in an amount of about 20 percent by weight to about 25 percent by weight, and a cyclohexyl biphenyl compound in an amount of about 15 percent by weight to about 20 percent by weight. The liquid crystal composition can improve the display quality and response time of a liquid crystal display (LCD) apparatus.

Claims

1. A liquid crystal composition comprising:

a bicyclohexyl compound in an amount of about 35 percent by weight to about 50 percent by weight, the bicyclohexyl compound represented by Chemical Formula 1;

a cyclohexyl phenyl compound in an amount of about 15 percent by weight to about 25 percent by weight, the cyclohexyl phenyl compound being represented by Chemical Formula 2;

a bicyclohexyl phenyl compound in an amount of about 20 percent by weight to about 25 percent by weight, the bicyclohexyl phenyl compound being represented by Chemical Formula 3; and

a cyclohexyl biphenyl compound in an amount of about 15 percent by weight to about 20 percent by weight, the cyclohexyl biphenyl compound being represented by Chemical Formula 4,

2. The liquid crystal composition of claim 1, wherein a rotation viscosity of the liquid crystal composition is from about 80 mPa·

s to about 165 mPa·

s.

3. The liquid crystal composition of claim 2, wherein each of X1, X2, X3, X4, Y1, Y2, Y3 and Y4 has a chain structure and five or less carbon atoms.

4. The liquid crystal composition of claim 3, further comprising a terphenyl compound in an amount of about 5 percent by weight or less, the terphenyl compound being represented by Chemical Formula 5,

5. The liquid crystal composition of claim 4, wherein each of X5 and Y5 has a chain structure and five or less carbon atoms.

6. The liquid crystal composition of claim 4, wherein a dielectric anisotropy of the liquid crystal composition is from about −

5.8 F/m to about −

2.7 F/m.

7. The liquid crystal composition of claim 6, wherein a refractive anisotropy of the liquid crystal composition is from about 0.075 to about 0.109.

8. A liquid crystal display (LCD) apparatus comprising:

a thin-film transistor (TFT) substrate comprising a gate line, a data line crossing over but not electrically connected to the gate line, a TFT connected to each of the gate line and the data line, and a pixel electrode electrically connected to the TFT;

an opposing substrate opposing the TFT substrate; and

a liquid crystal layer comprising a liquid crystal composition and being interposed between opposing surfaces of the TFT substrate and the opposing substrate, the liquid crystal composition comprising;

a bicyclohexyl compound in an amount of about 35 percent by weight to about 50 percent by weight, the bicyclohexyl compound being represented by Chemical Formula 1;

a cyclohexyl phenyl compound in an amount of about 15 percent by weight to about 25 percent by weight, the cyclohexyl phenyl compound being represented by Chemical Formula 2;

a bicyclohexyl phenyl compound in an amount of about 20 percent by weight to about 25 percent by weight, the bicyclohexyl phenyl compound being represented by Chemical Formula 3; and

a cyclohexyl biphenyl compound in an amount of about 15 percent by weight to about 20 percent by weight, the cyclohexyl biphenyl compound being represented by Chemical Formula 4,

9. The LCD apparatus of claim 8, wherein a rotation viscosity of the liquid crystal composition is from about 80 mPa·

s to about 165 mPa·

s.

10. The LCD apparatus of claim 9, wherein the liquid crystal composition further comprises a terphenyl compound in an amount of about 5 percent by weight or less, the terphenyl compound being represented by Chemical Formula 5.

11. The LCD apparatus of claim 10, wherein each of X1, X2, X3, X4, X5, Y1, Y2, Y3, Y4 and Y5 has a chain structure and five or less carbon atoms.

12. The LCD apparatus of claim 11, wherein the pixel electrode includes first domain partition portions dividing an area in which the pixel electrode is formed, into a plurality of domains.

13. The LCD apparatus of claim 12, wherein the opposing substrate has a common electrode including a plurality of second domain partition portion, and each of the second domain partition portions overlaps an area between the first domain partition portions adjacent to each other.

14. The LCD apparatus of claim 11, wherein the TFT substrate further comprises a color filter formed in the area in which the pixel electrode is formed.