Liquid crystal composition and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-9688915-B2
Application number	US-201414902333-A
Country	US
Kind code	B2
Filing date	Jun 9, 2014
Priority date	Jul 3, 2013
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of nematic phase, a low minimum temperature of nematic phase, small viscosity, suitable optical anisotropy, large positive dielectric anisotropy, large specific resistance, high stability to UV light and heat or a large elastic constant, or having a suitable balance regarding at least two of the characteristics, and an AM device having a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio and a long service life, etc. are described. The composition has a nematic phase and contains an additive that can suppress formation of an impurity, and a specific compound having large dielectric anisotropy as a first component, and may contain a specific compound having a high maximum temperature or small viscosity as a second component. The AM device is an LCD device including the composition.

First claim

The invention claimed is:

1. A liquid crystal composition that has a positive dielectric anisotropy and a nematic phase, and contains at least one compound selected from the group consisting of compounds having two or more monovalent groups represented by formula (1) as an additive, and at least one compound selected from the group consisting of compounds represented by formula (2) as a first component:

wherein in formulae (1) and (2), R 1 is hydrogen or alkyl having 1 to 15 carbons; R 2 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; ring A is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; Z 1 is a single bond, ethylene, carbonyloxy or difluoromethyleneoxy; X 1 and X 2 are independently hydrogen or fluorine; Y 1 is fluorine, chlorine, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by halogen, or alkoxy having 1 to 12 carbons in which at least one hydrogen is replaced by halogen; and a is 1, 2, 3 or 4,
wherein a proportion of the additive is in a range of 0.03 wt % to 0.3 wt % based on a weight of the liquid crystal composition, and
wherein at least one compound in the first component is a compound of formula (2) with X 1 , X 2 and Y 1 being fluorine.

2. The liquid crystal composition of claim 1 , containing at least one compound selected from the group consisting of compounds represented by formulae (1-1) and (1-2) as the additive:

wherein in formulae (1-1) and (1-2), R 1 , R 3 , R 4 and R 5 are independently hydrogen or alkyl having 1 to 15 carbons; Z 2 is alkylene having 1 to 20 carbons, and in the alkylene, at least one hydrogen may be replaced by halogen, and at least one —CH 2 —may be replaced by —O—.

3. The liquid crystal composition of claim 1 , wherein the first component contains at least one compound selected from the group consisting of compounds represented by fonnulae (2-2) to (2-13), (2-15) to (2-23) and (2-25) to (2-27):

wherein in formulae (2-2) to (2-13), (2-15) to (2-23) and (2-25) to (2-27), R 2 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons.

4. The liquid crystal composition of claim 1 , wherein a proportion of the first component is in a range of 10 wt % to 90 wt % based on a weight of the liquid crystal composition.

5. The liquid crystal composition of claim 1 , further containing at least one compound selected from the group consisting of compounds represented by formula (3) as a second component:

wherein in formula (3), R 6 and R 7 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which at least one hydrogen is replaced by fluorine; ring B and ring C are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; Z 3 is a single bond, ethylene or carbonyloxy; and b is 1, 2 or 3.

6. The liquid crystal composition of claim 5 , containing at least one compound selected from the group consisting of compounds represented by formulae (3-1) to (3-13) as the second component:

wherein in formulae (3-1) to (3-13), R 6 and R 7 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which at least one hydrogen is replaced by fluorine.

7. The liquid crystal composition of claim 5 , wherein a proportion of the second component is in a range of 10 wt % to 90 wt % based on a weight of the liquid crystal composition.

8. The liquid crystal composition of claim 1 , wherein a maximum temperature of a nematic phase is 70° C. or higher, an optical anisotropy (measured at 25° C.) at a wavelength of 589 nanometers is 0.07 or more and a dielectric anisotropy (measured at 25° C.) at a frequency of 1 kHz is 2 or more.

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

10. The liquid crystal display device of claim 9 , of which an operating mode includes a TN mode, an ECB mode, an OCB mode, an IPS mode, an FFS mode or an FPA mode, and a driving mode includes an active matrix mode.

11. The liquid crystal composition of claim 3 , wherein the first component further contains at least one compound selected from the group consisting of compounds represented by formulae (2-1), (2-14) and (2-24):

wherein in formulae (2-1), (2-14) and (2-24), R 2 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons.

Assignees

• Jnc Corp
• Jnc Petrochemical Corp

Inventors

• Furusato Yoshimasa
• Saito Masayuki

Classifications

• G02F1/0045

  Liquid crystals characterised by their physical properties · CPC title

• C09K2019/3083

  Cy-Ph-COO-Ph · CPC title

• C09K2019/3077

  Cy-Cy-COO-Ph · CPC title

• C09K2019/3422

  the heterocyclic ring being a six-membered ring · CPC title

• C09K19/44

  containing compounds with benzene rings directly linked · CPC title