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CN-122012116-A - Compound, liquid crystal medium and liquid crystal display comprising same

CN122012116ACN 122012116 ACN122012116 ACN 122012116ACN-122012116-A

Abstract

The invention relates to liquid-crystalline media, preferably having a nematic phase, comprising one or more compounds of formula (C), Wherein the parameters have the meanings given herein, to their use in energy-efficient electro-optical displays, in particular in active matrix displays based on the IPS or FFS effect, to displays of this type containing liquid-crystalline media of this type, and to the use of compounds of formula (C) for improving the contrast and/or response time of liquid-crystalline media comprising one or more further mesogenic compounds as defined herein.

Inventors

  • S C. Lott
  • M temperature moral Hirst
  • Zhen Bian Duxiao
  • C. BLOCK

Assignees

  • 默克专利股份有限公司

Dates

Publication Date
20260512
Application Date
20211220
Priority Date
20201222

Claims (13)

  1. 1. Liquid-crystalline medium, characterized in that it comprises one or more compounds of the formula C Wherein the method comprises the steps of R C1 and R C2 independently of one another represent alkyl having 1 to 15C atoms, wherein one or more CH 2 groups of these groups can each, independently of one another, be replaced by-CH=CH-, -C≡C-, -CF 2 O-、-OCF 2 -, -O-, - (CO) -O-, -O- (C=O) -, cyclopropylene, 1, 3-cyclobutylene, 1, 3-cyclopentylene, preferably by cyclopropylene or 1, 3-cyclopentylene, preferably one CH 2 group can be replaced by 1, 2-cyclopropyl, by 1, 3-cyclopentyl or by 1, 3-cyclopentylene, alkenyl, alkenyloxy, alkoxyalkyl or fluoroalkenyl having from 2 to 7C atoms, preferably alkyl or alkenyl, where one-CH 2 -group may be replaced by cyclopropylene, 1, 3-cyclobutylene, 1, 3-cyclopentylene, preferably by cyclopropylene or 1, 3-cyclopentylene, in such a way that the O atoms are not directly connected to one another and where one or more H atoms may be replaced by halogen, and Wherein each ring may be substituted by one or two alkyl groups, preferably methyl and/or ethyl groups, and One or more compounds of the formula B, Wherein the method comprises the steps of N represents 1 or 2, preferably 1, R 1 has one of the meanings given for R C1 and preferably represents alkyl having 1 to 7C atoms, wherein one or more CH 2 groups of these radicals may each, independently of one another, be replaced by-CH=CH-, -C.ident.C-, -CF 2 O-、-OCF 2 -, -O-, - (CO) -O-, -O- (C=O) -, cyclopropylene, 1, 3-cyclobutylene, 1, 3-cyclopentylene or 1, 3-cyclopentylene substitution, and X 1 represents F, cl, fluoroalkyl, fluoroalkenyl, fluoroalkoxy or fluoroalkenoxy.
  2. 2. The medium according to claim 1, characterized in that it comprises one or more compounds selected from the group consisting of compounds of formulae II and III Wherein the method comprises the steps of R 2 has one of the meanings given for R C1 in claim 1 and preferably denotes alkyl, alkoxy, fluoroalkyl or fluoroalkoxy having 1 to 7C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluoroalkenyl having 2 to 7C atoms, L 21 and L 22 represent H or F, X 2 represents halogen, halogenated alkyl or alkoxy having 1 to 3C atoms, or halogenated alkenyl or alkenyloxy having 2 or 3C atoms, M represents 0,1,2 or 3, R 3 has one of the meanings given for R C1 in claim 1 and preferably denotes alkyl, alkoxy, fluoroalkyl or fluoroalkoxy having 1 to 7C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluoroalkenyl having 2 to 7C atoms, L 31 and L 32 independently of one another represent H or F, X 3 represents halogen, halogenated alkyl or alkoxy having 1 to 3C atoms, or halogenated alkenyl or alkenyloxy having 2 or 3C atoms, F, cl, -OCF 3 、-OCHF 2 、-O-CH 2 CF 3 、-O-CH=CF 2 、-O-CH=CH 2 or-CF 3 , Z 3 represents-CH 2 CH 2 -、-CF 2 CF 2 -, -COO-, trans-CH=CH-, trans-cf=cf-, -CH 2 O-, or a single bond, and, a step of, in the first embodiment, N represents 0,1,2 or 3, Wherein each ring, preferably a phenylene ring, optionally may be each substituted with one or two alkyl groups, preferably with methyl and/or ethyl groups.
  3. 3. Medium according to claim 1 or 2, characterized in that it comprises one or more dielectrically neutral compounds selected from formulae IV and V: Wherein the method comprises the steps of R 41 and R 42 independently of one another have the meaning stated in claim 1 for R C1 , Z 41 and Z 42 independently of one another and if Z 41 occurs twice, these also represent-CH 2 CH 2 -, -COO-, trans-CH=CH-, trans-CF=CF-, -CH 2 O-,-CF 2 O-, -C≡C-, or a single bond, P represents a group selected from 0,1 or 2, R 51 and R 52 independently of one another have one of the meanings given above for R 41 and R 42 , Z 51 to Z 53 each independently of the others represent-CH 2 -CH 2 -,-CH 2 -O-, -ch=ch-, -c≡c-, -COO-, or a single bond, and I and j each independently of the other represent 0 or 1, Wherein each ring, preferably a phenylene ring, optionally may each be substituted with one or two alkyl groups.
  4. 4. A medium according to claim 1 to 3, comprising one or more compounds of the formula B, Wherein the method comprises the steps of N represents a number of 1 or 2, R 1 has one of the meanings given for R C1 in claim 1 and preferably represents alkyl, alkoxy, fluoroalkyl, fluoroalkoxy, alkenyl, alkenyloxy, alkoxyalkyl or fluoroalkenyl, and X 1 represents F, cl, fluoroalkyl, fluoroalkenyl, fluoroalkoxy or fluoroalkenoxy.
  5. 5. The medium according to at least one of claims 1 to 4, characterized in that it further comprises one or more compounds of formula I: Wherein the method comprises the steps of N represents 0 or 1 and is preferably selected from the group consisting of, R 11 and R 12 each independently of one another have one of the meanings given for R C1 in claim 1 and preferably denote alkyl, alkoxy, fluoroalkyl having 1 to 7C atoms, where one CH 2 group can be replaced by 1, 2-cyclopropyl, by 1, 3-cyclopentyl or by 1, 3-cyclopentylene, or fluoroalkoxy, alkenyl, alkenyloxy, alkoxyalkyl or fluoroalkenyl having 2 to 7C atoms, and R 11 optionally denotes R 1 and R 12 optionally denotes X 1 , R 1 has one of the meanings given for R C1 in claim 1 and preferably denotes alkyl, alkoxy, fluoroalkyl or fluoroalkoxy, preferably having 1 to 7C atoms, in which one CH 2 group can be replaced by 1, 2-cyclopropyl, by 1, 3-cyclopentyl or by 1, 3-cyclopentylene, alkenyl, alkenyloxy, alkoxyalkyl or fluoroalkenyl having 2 to 7C atoms, and preferably alkyl or alkenyl, and X 1 represents F, cl, fluoroalkyl, fluoroalkenyl, fluoroalkoxy or fluoroalkenoxy, Compounds of formulas B, VII and IX are not included therein, and Wherein each ring, preferably a phenylene ring, optionally may be each substituted with one or two alkyl groups, preferably with methyl and/or ethyl groups.
  6. 6. Medium according to at least one of claims 1 to 5, characterized in that it comprises one or more compounds selected from formulae VI to IX: Wherein the method comprises the steps of R 61 has one of the meanings given for R C1 in claim 1 and preferably denotes an unsubstituted alkyl radical having 1 to 7C atoms, an unsubstituted alkenyl radical having 2 to 7C atoms, an unsubstituted alkoxy radical having 1 to 6C atoms or an unsubstituted alkenyloxy radical having 2 to 6C atoms, R 62 has one of the meanings given for R C1 in claim 1 and preferably denotes an unsubstituted alkyl radical having 1 to 7C atoms, an unsubstituted alkoxy radical having 1 to 6C atoms or an unsubstituted alkenyloxy radical having 2 to 6C atoms, and L represents either 0 or 1 and is preferably used, R 71 has one of the meanings given for R C1 in claim 1 and preferably represents an unsubstituted alkyl radical having 1 to 7C atoms or an unsubstituted alkenyl radical having 2 to 7C atoms, R 72 has one of the meanings given for R C1 in claim 1 and preferably denotes an unsubstituted alkyl radical having 1 to 7C atoms, an unsubstituted alkoxy radical having 1 to 6C atoms or an unsubstituted alkenyloxy radical having 2 to 6C atoms, R 81 has one of the meanings given for R C1 in claim 1 and preferably represents an unsubstituted alkyl radical having 1 to 7C atoms or an unsubstituted alkenyl radical having 2 to 7C atoms, R 82 has one of the meanings given for R C1 in claim 1 and preferably denotes an unsubstituted alkyl radical having 1 to 7C atoms, an unsubstituted alkoxy radical having 1 to 6C atoms or an unsubstituted alkenyloxy radical having 2 to 6C atoms, preferably having 2,3 or 4C atoms, Z 8 represents- (c=o) -O-, -CH 2 -O-, -CF 2 -O-or-CH 2 -CH 2 -, O represents either 0 or 1 and, R 91 and R 92 independently of one another have the meanings given above for R 71 , P and q each independently of one another represent 0 or 1, And wherein each ring, preferably a phenylene ring, optionally may be substituted each by one or two alkyl groups, preferably methyl and/or ethyl groups, and the compounds of formula VII are excluded from the compounds of formula IX.
  7. 7. The medium according to at least one of claims 1 to 6, characterized in that the total concentration of the compound of formula B in the whole medium is 1% or more and 60% or less.
  8. 8. Medium according to at least one of claims 1 to 7, characterized in that it further comprises one or more chiral compounds and/or one or more stabilizers.
  9. 9. Electro-optic display or electro-optic component, characterized in that it comprises a liquid-crystalline medium according to at least one of claims 1 to 8.
  10. 10. Display according to claim 9, characterized in that it is based on IPS-or FFS mode.
  11. 11. A display as claimed in claim 9 or 10, characterized in that it comprises an active matrix addressing device.
  12. 12. Use of a medium according to at least one of claims 1 to 8 in an electro-optic display or an electro-optic assembly.
  13. 13. Process for preparing a liquid-crystalline medium according to one or more of claims 1 to 8, characterized in that one or more compounds of the formula C are mixed with one or more further mesogenic compounds and optionally one or more additives.

Description

Compound, liquid crystal medium and liquid crystal display comprising same The application is a divisional application of patent application number 202180086040.0. Technical Field The present invention relates to novel liquid-crystalline media, in particular for energy-efficient liquid-crystal displays, and to these liquid-crystal displays, in particular liquid-crystal displays using the IPS (in-plane switching) or preferably FFS (fringe field switching) effect (both using dielectrically positive liquid crystals). The latter is occasionally also referred to as the XB-FFS (super bright FFS) effect. Background For this effect, dielectrically positive liquid crystals are used which comprise one or more compounds having both a high dielectric constant parallel to the molecular director and perpendicular to the molecular director, which results in a large average dielectric constant and a high dielectric ratio and preferably simultaneously in a relatively small dielectric anisotropy. The liquid-crystalline medium optionally additionally comprises a dielectrically negative compound, a dielectrically neutral compound or both. The liquid crystal medium is used for planar (i.e., planar) initial alignment. The liquid-crystalline medium according to the invention has a positive dielectric anisotropy and comprises compounds having a large dielectric constant both parallel to the molecular director and perpendicular to the molecular director. The media are characterized by particularly good performance for dark states, mainly due to their very low scattering. This in turn is caused in particular by their high elastic constants. High elastic constants may also lead to higher rotational viscosity values (γ1). And thus a higher ratio γ1/k 22 of rotational viscosity (γ1) to the elastic constant (k 22) of the torsional variant, which in turn leads to a higher response time. Since k 22 is approximately proportional to the spring constant of the splay deformation, k 11 (the value of k 22 is typically about half the value of k 11), γ1 and k 11 can be easily and conveniently determined approximately. The contrast of the LC display can be improved on the one hand by the higher transmittance that can be achieved by the higher epsilon ⊥ in the FFS cell layout. And, on the other hand, it can be improved by a better dark state. The latter, i.e. the dark state, is strongly influenced in particular by the scattering parameters. Herein, a liquid crystal medium having a high elastic constant reduces scattering, thus improving contrast ratio of the LCD. This also results in their excellent performance in the display according to the invention. IPS and FFS displays using dielectrically positive liquid crystals are well known in the art and have been widely adopted for various types of displays, such as desktop monitors and televisions, and for mobile applications. However, at present, IPS and particularly FFS displays using a dielectric negative liquid crystal are widely adopted. The latter is sometimes also referred to as UB-FFS (super bright FFS). Such a display is disclosed for example in US 2013/0207038 A1. These displays are characterized by a significantly increased transmittance compared to the previously used IPS-and FFS-displays of dielectrically positive liquid crystals. However, these displays using conventional dielectric negative liquid crystals have the serious disadvantage that a higher operating voltage is required than for each display using dielectric positive liquid crystals. The liquid-crystalline medium used for UB-FFS has a dielectric anisotropy of-0.5 or less and preferably-1.5 or less. The liquid crystal medium for HB-FFS (high brightness FFS) has a dielectric anisotropy of 0.5 or more and preferably 1.5 or more. Liquid crystal media for HB-FFS comprising both dielectrically negative and dielectrically positive liquid crystal compounds, or mesogenic compounds, are disclosed for example in US2013/0207038 A1. These media are characterized by already having considerable epsilon ⊥ and epsilon av. values, but their ratio (epsilon ⊥/delta epsilon) is relatively small. However, according to the invention, preference is given to IPS or FFS effects with a dielectrically positive liquid-crystalline medium which is aligned along the plane. The industrial application of this effect in electro-optic display elements requires a liquid crystal phase which must meet a number of requirements. Of particular importance here are chemical resistance and physical effects on moisture, air, such as radiation in the thermal, infrared, visible and ultraviolet regions, and Direct Current (DC) and Alternating Current (AC) electric fields. In addition, industrially useful liquid crystal phases are required to have a liquid crystal mesophase at a suitable temperature range and low viscosity. None of the series of compounds with liquid crystalline mesophases which have been disclosed so far include a single compound which meets all of these requi