Search

US-12618008-B2 - Liquid crystal medium

US12618008B2US 12618008 B2US12618008 B2US 12618008B2US-12618008-B2

Abstract

Liquid-crystalline (LC) media having positive dielectric anisotropy and liquid-crystal displays (LCDs) containing these media. Also, displays addressed by an active matrix and LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer-stabilized SA-HB-FFS, polymer-stabilized SA-XB-FFS, positive VA, or positive PS-VA type.

Inventors

  • Jing Wang
  • Hee-Kyu LEE
  • Sven Christian Laut
  • Aaron Lackner
  • Dmitry Ushakov
  • Rocco Fortte
  • Philipp Wucher

Assignees

  • MERCK PATENT GMBH

Dates

Publication Date
20260505
Application Date
20250428
Priority Date
20240522

Claims (12)

  1. 1 . A liquid crystal medium comprising: one or more compounds of formula I: in which R 11 and R 12 identically or differently, denote H, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms, wherein one or more CH 2 groups are optionally replaced, independently of one another, by —CH═CH—, —C≡C—, —CF 2 O—, —OCF 2 —, —O—, —CO—O—, or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by halogen; and L 11 , L 12 , L 13 , and L 14 identically or differently, denote H, F, Cl, CH 3 , CF 3 , or CHF 2 , wherein at least one of L 11 , L 12 , L 13 , or L 1 denotes F, Cl, CH 3 , CF 3 , or CHF 2 ; and one or more compounds of formula VIII: in which R 81 and R 82 identically or differently, denote H, halogen, CN, SCN, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms, where one or more CH 2 groups are optionally replaced, independently of one another, by —C≡C—, —CF 2 O—, —OCF 2 —, —CH═CH—, —O—, —CO—O—, or —O—CO— in such a way that 0 atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by halogen; A 0 , A 81 , and A 82 each, independently of one another, denote phenylene-1,4-diyl, in which one or two CH groups are optionally replaced by N and one or more H atoms are optionally replaced by halogen, CN, CH 3 , CHF 2 , CH 2 F, CF 3 , OCH 3 , OCHF 2 , or OCF 3 , cyclohexane-1,4-diyl, in which one or two non-adjacent CH 2 groups are optionally replaced, independently of one another, by O and/or S and one or more H atoms are optionally replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]-pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl, or 1,3-dioxane-2,5-diyl; Z 81 and Z 82 each, independently of one another, denote —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CO—O—, —O—CO—, —C 2 H 4 —, —C 2 F 4 , —CF 2 CH 2 —, —CH 2 CF 2 —, —CFHCFH—, —CFHCH 2 —, —CH 2 CFH—, —CF 2 CFH—, —CFHCF 2 —, —CH═CH—, —CF═CH—, —CH═CF—, —CF═CF—, —C≡C—, or a single bond; n denotes 0, 1, 2, or 3, and m denotes 0, 1, 2, or 3.
  2. 2 . The liquid crystal medium according to claim 1 , wherein the medium further comprises one or more compounds selected from formulae II and III: in which R 2 and R 3 independently of one another, denote H, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms, where one or more CH 2 groups in the straight-chain alkyl or alkoxy group having 1 to 15 C atoms, the straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or the branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms are optionally replaced, independently of one another, by —CH═CH—, —C≡C—, —CF 2 O—, —OCF 2 —, —O—, —CO—O—, or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by halogen; and independently of one another denote L 21 , L 22 , L 31 , and L 32 independently of each other, denote H or F; Y 2 and Y 3 identically or differently, denote H or CH 3 ; X 2 and X 3 independently of each other, denote halogen, a halogenated alkyl or alkoxy group with 1 to 3 C atoms, or a halogenated alkenyl or alkenyloxy group with 2 or 3 C atoms; Z 3 denotes —CH 2 CH 2 —, —CF 2 CF 2 —, —COO—, trans- —CH═CH—, trans- —CF═CF—, —CH 2 O—, or a single bond; and l, m, n, and o are, independently of each other, 0 or 1.
  3. 3 . The liquid crystal medium according to claim 1 , wherein the medium further comprises one or more compounds selected from formulae II-1, II-2, and II-3: in which L 21 , L 22 , L 23 , and L 24 independently of each other, denote H or F; R 2 denotes H, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms, where one or more CH 2 are optionally replaced, independently of one another, by —CH═CH—, —C═C—, —CF 2 O—, —OCF 2 —, —O—, —CO—O—, or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by halogen; X 2 denotes halogen, a halogenated alkyl or alkoxy group with 1 to 3 C atoms, or a halogenated alkenyl or independently of one another, denote
  4. 4 . The liquid crystal medium according to claim 1 , wherein the medium further comprises one or more compounds selected from formulae III-1 and III-2: in which R 3 denotes H, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms, where one or more CH 2 groups are optionally replaced, independently of one another, by —CH═CH—, —C═C—, —CF 2 O—, —OCF 2 —, —O—, —CO—O—, or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by halogen; and independently of one another, denote L 31 and L 32 independently of each other, denote H or F; X 3 denotes halogen, a halogenated alkyl or alkoxy group with 1 to 3 C atoms, or a halogenated alkenyl or alkenyloxy group with 2 or 3 C atoms; Z 3 denotes —CH 2 CH 2 —, —CF 2 CF 2 —, —COO—, trans- —CH═CH—, trans- —CF═CF—, —CH 2 O—, or a single bond; and n and o are, independently of each other, 0 or 1.
  5. 5 . The liquid crystal medium according to claim 1 , wherein the medium further comprises one or more compounds selected from the group consisting of formulae Y, B, BC, CR, PH-1, and PH-2: in which R Y1 , R Y2 , R B1 , R B2 , R CR1 , R CR2 , R P1 , and R P2 each, independently of one another, denote H, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms, where one or more CH 2 groups in the straight-chain alkyl or alkoxy group having 1 to 15 C atoms, the straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or the branched alkyl, alkoxy, alkenyl, or alkenyloxy group having 3 to 15 C atoms are optionally replaced, independently of one another, by —CH═CH—, —C═C—, —CF 2 O—, —OCF 2 —, —O—, —CO—O—, or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by halogen; and on each occurrence, independently of one another, denote a) 1,4-cyclohexylene or 1,4-cyclohexenylene radical, in which one or two non-adjacent CH 2 groups are optionally replaced by —O— or —S—; b) a 1,4-phenylene radical, in which one or two CH groups are optionally replaced by N; or c) a radical from the group spiro[3.3]heptane-2,6-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl, and fluorene-2,7-diyl, where the radicals a), b), and c) are optionally mono- or poly-substituted by halogen atoms; Z x and Z y identically or differently, denote —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CO—O—, —O—CO—, —C 2 F 4 —, —CF═CF—, —CH═CH—CH 2 O—, or a single bond; Z 1 denotes —CO—O—, —O—CO—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CH 2 —, —CH 2 CH 2 —, —(CH 2 ) 4 —, —CH═CH—CH 2 O—, —C 2 F 4 —, —CH 2 CF 2 —, —CF 2 CH 2 —, —CF═CF—, —CH═CF—, —CF═CH—, —CH═CH—, —C═C—, or a single bond; L Y1 , L Y2 , L B1 , and L B2 each, independently of one another, denote F, Cl, CF 3 or CHF 2 ; W denotes O or S; n is 0, 1, or 2; c is 0, 1, or 2; and x and y independently, are 0, 1, or 2, where x+y≤3.
  6. 6 . The liquid crystal medium according to claim 1 , wherein the medium further comprises one or more compounds of formula VII: in which R 71 and R 72 denote H, F, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl, alkoxy, alkenyl, or alkenyloxy group each having 3 to 15 C atoms, where one or more CH 2 groups in the straight-chain alkyl or alkoxy group having 1 to 15 C atoms, the straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms, or the branched alkyl, alkoxy, alkenyl, or alkenyloxy group each having 3 to 15 C atoms are optionally replaced, independently of one another, by —C═C—, —CF 2 O—, —OCF 2 —, —CH═CH—, —O—, —CO—O—, or —O—CO— in such a way that O atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by halogen; X 71 , X 72 , X 73 , X 74 , X 75 and X 76 identically or differently, denote H or F; and Z 71 and Z 72 identically or differently, denote CH 2 CH 2 or a single bond.
  7. 7 . The liquid crystal medium according to claim 1 , wherein the medium comprises one or more compounds of formula IV: in which R 11 denotes a straight-chain alkyl or alkoxy radical having 1 to 12 C atoms, a branched or cyclic alkyl radical having 3 to 12 C atoms, a straight-chain alkenyl radical having 2 to 12 C atoms, a branched alkenyl radical having 3 to 12 C atoms, or a cyclic alkenyl radical having 5 to 12 C atoms, wherein one or more H atoms are optionally replaced by fluorine; and R 12 denotes a straight-chain alkyl or alkoxy radical having 1 to 12 C atoms, a branched or cyclic alkyl or alkoxy radical having 3 to 12 C atoms, a straight-chain alkenyl radical having 2 to 12 C atoms, a branched alkenyl radical having 3 to 12 C atoms, or a cyclic alkenyl radical having 5 to 12 C atoms, wherein one or more H atoms are optionally replaced by fluorine.
  8. 8 . The liquid crystal medium according to claim 1 , wherein the medium comprises one or more compounds of formulae IVa and/or IVb: in which R 41 and R 42 each, independently of one another, denote a straight-chain alkyl, alkoxy, alkenyl, alkoxyalkyl, or alkenyloxy radical having up to 12 C atoms; denotes and Z 4 denotes a single bond, —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —COO—, —OCO—, —C 2 F 4 —, —C 4 H 8 —, or —CF═CF—.
  9. 9 . The liquid crystal medium according to claim 1 , wherein the medium further comprises one or more compounds of formula V: in which R 51 and R 52 denote an alkyl group having 1 to 7 C atoms, an alkoxy group having 1 to 7 C atoms, or an alkoxyalkyl, alkenyl, or alkenyloxy group having 2 to 7 C atoms; identically or differently, denote Z 51 and Z 52 each, independently of one another, denote —CH 2 —CH 2 —, —CH 2 —O—, —CH═CH—, —C═C—, —COO—, or a single bond; and n is 1 or 2.
  10. 10 . The liquid crystal medium according to claim 1 , wherein the medium further comprises one or more compounds of formula V-3: in which R 51 and R 52 denote an alkyl group having 1 to 7 C atoms, an alkoxy group having 1 to 7 C atoms, or an alkoxyalkyl, alkenyl, or alkenyloxy group having 2 to 7 C atoms; denotes and Z 51 denotes —CH 2 —CH 2 —, —CH 2 —O—, —CH═CH—, —C═C—, —COO—, or a single bond.
  11. 11 . A liquid crystal display comprising the liquid-crystal medium according to claim 1 .
  12. 12 . The liquid crystal display according to claim 11 , wherein the display is configured to operate under IPS or FFS mode.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This is a U.S. nonprovisional patent application filed under 35 U.S.C. § 111 (a), claiming priority benefit under 35 U.S.C. § 119 (a) of and to PCT International Application No. PCT/CN2024/094658, filed May 22, 2024, the contents of which documents are incorporated herein by reference in their entirety and for all purposes. FIELD OF INVENTION The present invention relates to liquid-crystalline (LC) media having positive dielectric anisotropy and to liquid-crystal displays (LCDs) containing these media, especially to displays addressed by an active matrix and in particular to LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, PS-HB-FFS, SA-HB-FFS, polymer-stabilized SA-HB-FFS, positive VA, or positive PS-VA type. BACKGROUND Liquid crystal displays (LCDs) are used in many areas for the display of information. LCDs are used both for direct-view displays and for projection-type displays. The electro-optical modes used are, for example, the twisted nematic (TN), super twisted nematic (STN), optically compensated bend (OCB), and electrically controlled birefringence (ECB) modes, together with their various modifications, as well as others. All these modes utilize an electric field which is generated substantially perpendicular to the substrates and the liquid-crystal layer. Besides these modes, there are also electro-optical modes that utilize an electric field which is substantially parallel to the substrates or the liquid-crystal layer. For example, WO 91/10936 discloses a liquid-crystal display in which the electric signals are generated in such a way that the electric fields have a significant component parallel to the liquid-crystal layer, and which has since then become known as in-plane switching IPS) display. The principles of operating such a display are described, for example, by R. A. Soref in Journal of Applied Physics, Vol. 45, No. 12, pp. 5466-5468 (1974). IPS displays contain an LC layer between two substrates with a planar orientation, where the two electrodes are arranged on only one of the two substrates and preferably have interdigitated, comb-shaped structures. Upon application of a voltage to the electrodes, an electric field with a significant component parallel to the LC layer is generated between them. This applied voltage causes realignment of the LC molecules in the layer plane. EP 0 588 568, for example, discloses various possibilities for the design of the electrodes and for addressing an IPS display. DE 198 24 137 likewise describes various embodiments of such IPS displays. Liquid-crystalline materials for IPS displays of this type are described, for example, in DE 195 28 104. Furthermore, so-called “fringe-field switching” (FFS) displays have been reported (see, inter alia, S. H. Jung et al., Jpn. J. Appl. Phys., Volume 43, No. 3, 2004, 1028), which contain two electrodes on the same substrate, one of which is structured in a comb-shaped manner and the other is unstructured. A strong, so-called “fringe field” is thereby generated, i.e., a strong electric field close to the edge of the electrodes, and, throughout the cell, an electric field which has both a strong vertical component and a strong horizontal component. FFS displays have a low viewing-angle dependence of the contrast. FFS displays usually contain an LC medium with positive dielectric anisotropy, and an alignment layer, usually of polyimide, which provides planar alignment to the molecules of the LC medium. Liquid-crystal displays of the IPS and FFS electro-optical modes are in particular suitable for use in not only modern desktop monitors, TV sets, and multimedia applications, but also for mobile phones, tablet PCs, and the like. The liquid-crystalline media according to the present invention are preferably used in displays of this type. In general, dielectrically positive liquid-crystalline media having rather lower values of the dielectric anisotropy are used in FFS displays, but in some cases, liquid-crystalline media having a dielectric anisotropy of only about 3 or even less are also used in IPS displays. A further improvement has been achieved by the so-called HB-FFS mode. One of the unique features of the HB-FFS mode in contrast to the traditional FFS technology is that it enables higher transmittance, which allows operation of the panel with less energy consumption. Liquid-crystal compositions which are suitable for LCDs and especially for FFS and IPS displays are known in prior art, for example, from JP 07-181 439 (A), EP 0 667 555, EP 0 673 986, DE 195 09 410, DE 195 28 106, DE 195 28 107, WO 96/23 851, and WO 96/28 521. However, these compositions have certain disadvantages. Amongst other deficiencies, most of them result in disadvantageously long addressing times, have inadequate values of the resistivity, and/or require excessively high operating voltages. FFS and IPS displays can be operated as active-matrix displays (AMD) or passive-matrix dis