45results about How to "Large negative dielectric anisotropy" patented technology

A liquid crystal compound having high stability to heat, light and so forth, a high clearing point, a low minimum temperature of a liquid crystal phase, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, a suitable elastic constant and excellent compatibility with other liquid crystal compounds, a liquid crystal composition containing the compound, and a liquid crystal display device including the composition. The compound is represented by formula (1-1):

wherein, for example, R¹ is alkyl having 1 to 10 carbons, alkoxy having 1 to 9 carbons or alkenyl having 2 to 10 carbons; R² is alkyl having 1 to 10 carbons, alkoxy having 1 to 9 carbons or alkenyl having 3 to 10 carbons; ring A¹ is 1,4-cyclohexylene or 1,4-phenylene; ring A² is 1,4-cyclohexylene, 1,4-phenylene or 2,3-difluoro-1,4-phenylene; Z¹ and Z² are single bonds; L¹ and L² are fluorine; and 1 is 0, 1 or 2.

The invention relates to the field of liquid crystal display, in particular to a liquid crystal medium and application thereof. The liquid crystal medium comprises at least one compound represented bya general formula I and at least one compound represented by a general formula II, wherein the compound represented by the general formula I is a tricyclic compound containing a 2,3-difluorobenzene structure which has higher negative dielectric anisotropy and a high bright spot; the compound represented by the general formula II is a dicyclic compound containing a 2,3-difluorobenzene structure which is a negative dielectric anisotropic liquid crystal compound which adopts a fluoroethoxy structure at the tail end, thereby greatly improving the dielectric anisotropy of the liquid crystal compound. The liquid crystal medium provided by the invention has low rotating viscosity, high low-temperature mutual solubility and fast response time, is suitable for VA type liquid crystal display devices such as VA/MVA/PVA/PSVA as well as IPS and FFS mode liquid crystal display devices, and is very useful for improving the response time of liquid crystal display. The general formula I and the general formula II are shown in the description.

The invention relates to a negative dielectric anisotropic liquid crystal composition and applications thereof. The liquid crystal composition comprises at least one or more compounds represented by the formula I and one or more compounds represented by the formula II. The provided liquid crystal composition has the advantages of low rotary viscosity, large elastic constant, good low temperature inter-solubility, and quick response speed, can be applied to multiple display modes of quick response liquid crystal display, and can obviously improves the display effect of a liquid crystal displayof a VA/MV/PVA/PSVA, IPS or FFS mode.

To provide a liquid crystal compound satisfying at least one of high stability to heat, light and so forth, a high clearing point, a low minimum temperature of a liquid crystal phase, small viscosity, suitable optical anisotropy, large dielectric anisotropy, a suitable elastic constant and excellent compatibility with other liquid crystal compounds, a liquid crystal composition containing the compound, and a liquid crystal display device including the composition.

The compound is represented by formula (1):

wherein, for example, R is alkyl having 1 to 10 carbons or alkoxy having 1 to 9 carbons; ring A¹, ring A² and ring A³ is 1,4-cyclohexylene, 1,4-phenylene or 2,3-difluoro-1,4-phenylene; at least one of L¹ and L² is fluorine and the remainder is hydrogen; Z¹, Z² and Z³ are a single bond, —(CH₂)₂—, —CH₂O— or —COO—; x and y are an integer from 0 to 10; and l, m and n are 0 or 1.

To provide a liquid crystal compound satisfying at least one of physical properties such as a high stability to heat, light and so forth, a high clearing point, a low minimum temperature of a liquid crystal phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a suitable elastic constant and an excellent compatibility with other liquid crystal compounds; a liquid crystal composition containing the compound; and a liquid crystal display device including the composition. The compound is represented by formula (1):

wherein, for example, Ra and Rb are alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons or alkoxy having 1 to 9 carbons; A¹, A² and A³ are 1,4-cyclohexylene or 1,4-phenylene; Z¹ and Z² are single bonds, —(CH₂)₂—, —CH═CH—, —COO—, —OCO—, —CF₂O—, —OCF₂—, —CH₂O— or —OCH₂—; Y¹ is —CF₂H or —CF₃; Y² is fluorine; and a, b and d are 0, 1, 2 or 3, and c is 1 or 3.

The invention relates to the field of liquid crystal display, and particularly relates to a nematic liquid crystal composition containing a fluoroethoxy structure. The nematic liquid crystal composition contains at least one compound represented by a general formula I and at least one compound represented by a general formula II, wherein the compound represented by the formula I is a liquid crystal compound which is of a 2, 3-difluorobenzene structure, the compound has relatively great negative dielectric anisotropy and a high clearing point; and the compound represented by the formula II is abicyclic liquid crystal compound having 2, 3-difluoro-1, 4-phenyl, and a terminus is of a fluoroethoxy structure for greatly improving dielectric anisotropy of the liquid crystal compound. The liquidcrystal composition provided by the invention has low rotational viscosity, excellent low-temperature intersolubility and fast response, is suitable for VA-type liquid crystal display devices such asVA/MVA/PVA/PSVA as well as IPS and FFS mode liquid crystal display devices, and is very effective for improving the response time of liquid crystal displays.

This invention relates to a method for preparing a fluorine-containing organic intermediate, more specifically, 2, 3-difluoro-4-bromophenetole. The method comprises: bromating 2, 3-difluorophenol by Br2 in the presence of solvent and organic acid to obtain 2,3-difluoro-4-bromophenol with content higher than 95%, recrystallizing to obtain 2,3-difluoro-4-bromophenol with a content higher than 99%, and etherifying with bromoethane or diethyl sulfate to obtain 2,3-difluoro-4-bromophenetole. The method has such advantages as abundant raw materials, reasonable process, easy operation, low cost, and high yield. The prepared 2,3-difluoro-4-bromophenetole can be used in the formula of liquid crystal material with high negative dielectric anisotropy, appropriate double refraction, wide nematic range, and low viscoelasticity.

The invention relates to the field of liquid crystal displays, in particular to a liquid crystal medium and application thereof. The liquid crystal medium comprises at least one compound shown as a general formula I and at least one compound shown as a general formula II, wherein the compound shown as the general formula I is a tricyclic compound containing a 2,3-difluorobenzene structure, and thestructure has a relatively large negative dielectric anisotropy and a high clearing point; the compound shown as the general formula II, provided by the invention, is a bicyclic compound containing a2,3-difluorobenzene structure, and the structure is a negative dielectric anisotropic liquid crystal compound which adopts a fluoroethoxy structure at a terminal so as to greatly enhance the dielectric anisotropy of the liquid crystal compound. The liquid crystal medium provided by the invention has low rotational viscosity, good low-temperature intersolubility and a short response time, is suitable for VA liquid crystal display devices such as VA/MVA/PVA/PSVA and IPS-mode and FFS-mode liquid crystal display devices, and is very effective for shortening the response time of liquid crystal displays.

The invention relates to the field of liquid crystal display, in particular to a liquid crystal medium and application thereof. The liquid crystal medium at least contains a compound represented by ageneral formula I and at least one compound represented by at least one general formula II, wherein the compound represented by the general formula I is a three-ring compound with 2,3-difluorobenzenestructures; the structure has greater negative dielectric anisotropy and high clear points; the compound represented by the general formula II provided by the invention is a two ring compound with 2,3-difluorobenzene structures; the structure is the negative dielectric anisotropy liquid crystal compounds; the fluoro ethyoxyl structure is used as the tail end; the dielectric anisotropy of the liquid crystal compound is greatly improved. The liquid crystal medium provided by the invention has low rotary viscosity, good low-temperature mutual solubility and fast response time, is applicable to VAtype liquid crystal display devices such as VA/MVA/PVA/PSVA and IPS and FFS mode liquid crystal display devices; the medium is very effective on the improvement of the response time of the liquid crystal display. (The formulas are shown in the description.).

The invention discloses a high-transmittance liquid crystal composition with negative dielectric anisotropy. The liquid crystal composition contains: one or more compounds as shown in general formulaI-1 and/or I-2, which account for 20-60% of the total weight of a negative liquid crystal composition; one or more compounds as shown in a general formula II, which account for 12-40% of the total weight of the negative liquid crystal composition; one or more compounds as shown in general formula III, which account for 12-40% of the total weight of the negative liquid crystal composition; and oneor more compounds as shown in general formula IV, which account for 20-60% of the total weight of the negative liquid crystal composition. The invention also discloses a liquid crystal display devicecomprising the liquid crystal composition. The formulae are as shown in the specification.

The invention provides a liquid crystal compound and application thereof. The liquid crystal composition comprises at least one compound as shown in a formula I as described in the specification, wherein the compound accounts for 1-20% by weight of the liquid crystal composition, at least one compound selected from formulae II-1, II-2, II-3 and II-4 and a group of the combination thereof, whereinthe compound accounts for 25-80% by weight of the liquid crystal composition; and at least one compound selected from formulae III-1, III-2, III-3 and III-4 and a group of the combination thereof, wherein the compound accounts for 20-75% by weight of the liquid crystal composition. The liquid crystal composition provided by the invention has proper optical anisotropism, relatively high clearing points, relatively great negative dielectric anisotropy, low viscosity and high reliability, is suitable for a liquid crystal display and meets the demand of quick response of the liquid crystal display. The invention also provides a compound meeting the formula I-2 as shown in the specification.

The invention discloses a liquid crystal compound, the structural formula of the liquid crystal compound is shown as the following formula I, and the liquid crystal compound has good reliability, goodlow-temperature inter-solubility and high response speed. The invention also discloses a liquid crystal composition containing the liquid crystal compound and a liquid crystal display element or a liquid crystal display.

A means is a compound represented by formula (1) , a liquid crystal composition containing the compound, and a liquid crystal display device including the composition.

In formula (1), R¹ and R² are independently alkyl having 1 to 15 carbons or the like; ring A¹, ring A² and ring A³ are independently 1,4-cyclohexylene, 1,4-phenylene or the like; and Z¹, Z² and Z³ are independently a single bond or the like.