LCD media

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal medium.SOLUTION: The present invention relates to a liquid crystal (LC) medium containing a polymerizable compound, a preparation method thereof, a use thereof for optical, electro-optical, and electronic purposes, especially for LC displays, especially for polymer sustained alignment (PSA)-type LC displays and an LC display containing the LC medium, especially the PSA display.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal (LC) medium comprising a polymerizable compound, to a process for preparing it, to its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially LC displays of the polymer sustained alignment (PSA) type, and to LC displays, especially PSA displays, containing it. [Background technology]

[0002] The liquid crystal display modes that have found widespread interest and commercial use to date are the so-called PS ("polymer sustained") or PSA ("polymer sustained alignment") modes, for which the term "polymer stabilized" is sometimes used. PSA displays use an LC medium containing an LC mixture (hereafter also referred to as the "host mixture") and a small amount of one or more polymerizable compounds, preferably polymerizable monomeric compounds, typically less than 1% by weight, e.g., 0.2-0.4% by weight. After the LC medium is filled into the display, the polymerizable compounds are polymerized or crosslinked in situ, usually by UV photopolymerization, while optionally applying a voltage to the display electrodes. Polymerization is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, usually at room temperature. The addition of polymerizable mesogens or liquid crystal compounds, also known as reactive mesogens or "RMs," to the LC host mixture has proven particularly suitable.

[0003] The PS(A) mode is currently used in various conventional types of LC displays. For example, PS-VA ("vertically aligned"), PS-OCB ("optically compensated bend"), PS-IPS ("in-plane switching"), PS-FFS ("fringe field switching"), PS-UB-FFS ("Ultra Brightness FFS"), and PS-TN ("twisted nematic") displays are known. In the case of PS-VA and PS-OCB displays, the RM is polymerized preferably with an applied voltage, while in the case of PS-IPS displays, the RM is polymerized with or without, preferably without, an applied voltage. As a result, a pretilt angle of the LC molecules is generated in the display cell. For example, in the case of PS-OCB displays, the bend structure can be stabilized, eliminating or reducing the need for an offset voltage. In the case of PS-VA displays, the pretilt has a positive effect on the response time. For PS-VA displays, standard MVA ("multi domain VA") or PVA ("patterned VA") pixel and electrode layouts can be used. It is also possible to use electrodes structured on only one side without protrusions, which significantly simplifies manufacturing and improves contrast and transparency.

[0004] Furthermore, the so-called positive-VA ("positive VA") mode has proven particularly suitable. Similar to conventional VA and PS-VA displays, in the initial state with no applied voltage, the initial orientation of the LC molecules in a positive-VA display is homeotropic, i.e., substantially perpendicular to the substrates. However, in contrast to conventional VA and PS-VA displays, a positive-VA display uses an LC medium with positive dielectric anisotropy. Similar to IPS and PS-IPS displays, the two electrodes in a positive-VA display are located on only one of the two substrates and preferably exhibit an interdigitated (interdigitated) structure. When a voltage is applied to the interdigitated electrodes, the electrodes generate an electric field substantially parallel to the layer of the LC medium, causing the LC molecules to switch to an orientation substantially parallel to the substrates. Also in positive-VA displays, polymer stabilization, which involves adding an RM to the LC medium and then polymerizing it within the display, has proven advantageous. This allows for significantly shorter switching times.

[0005] PS-VA displays are described, for example, in European Patent Application Publication No. 1170626 (Patent Document 1), U.S. Patent No. 6861107 (Patent Document 2), U.S. Patent No. 7169449 (Patent Document 3), U.S. Patent Application Publication No. 2004 / 0191428 (Patent Document 4), U.S. Patent Application Publication No. 2006 / 0066793 (Patent Document 5) and U.S. Patent Application Publication No. 2006 / 0103804 (Patent Document 6). PS-OCB displays are described, for example, in T.-J-Chen et al., Jpn.J.Appl.Phys., Vol. 45, 2006, pp. 2702-2704 (Non-Patent Document 1) and SHKim, L.-C-Chien, Jpn.J.Appl.Phys., Vol. 43, 2004, pp. 7643-7647 (Non-Patent Document 2). A PS-IPS display is described, for example, in U.S. Pat. No. 6,177,972 (Patent Document 7) and Appl. Phys. Lett. 1999, Vol. 75 (No. 21), p. 3264 (Non-Patent Document 3). A PS-TN display is described, for example, in Optics Express 2004, Vol. 12 (No. 7), p. 1221 (Non-Patent Document 4).

[0006] PSA displays can operate as either active matrix or passive matrix displays, where in the case of active matrix displays, individual pixels are typically addressed by integrated non-linear active elements such as transistors (such as thin-film transistors or TFTs), while in passive matrix displays, individual pixels are typically addressed by a multiplexing method, as is known from the prior art.

[0007] PSA displays may also include alignment layers on one or both of the substrates forming the display cell. The alignment layers are typically coated on the electrodes (if such electrodes are present) so as to contact the LC medium and induce initial alignment of the LC molecules. The alignment layers may, for example, comprise or consist of polyimide, and may be rubbed or prepared by photoalignment methods.

[0008] In particular, for monitor and especially television applications, it remains desirable to optimize not only the response time but also the contrast and brightness (and therefore the transmittance) of LC displays. Here, the PSA method can offer important advantages. In particular, for PS-VA, PS-IPS, PS-FFS and PS-positive-VA displays, a reduction in response time can be achieved, correlated with a measurable pretilt in test cells, without significantly affecting other parameters.

[0009] Biphenyl diacrylate or biphenyl dimethacrylate, which may be fluorinated, has been suggested in the prior art as an RM for use in PSA displays.

[0010] However, a problem arises in that not all combinations of LC host mixtures and RMs are suitable for use in PSA displays, for example, because they can only produce inappropriate tilt angles or no tilt angles at all, or because, for example, their voltage holding ratios (VHRs) are inappropriate for TFT display applications. In addition, it has been found that LC mixtures and RMs known from the prior art still have some disadvantages when used in PSA displays. Therefore, not all known RMs that are soluble in LC host mixtures are suitable for use in PSA displays. In addition, it is often difficult to directly measure the pretilt in PSA displays and to find appropriate selection requirements for RMs. When UV photopolymerization without the addition of a photoinitiator is desired, which is advantageous for certain applications, the scope for selecting a suitable RM becomes even narrower.

[0011] In addition, the selected LC host mixture / polymerizable compound combination must have low rotational viscosity and good electrical properties, especially a high VHR. A high VHR after UV light exposure is particularly important for PSA displays, since UV exposure is not only a normal part of the operation of the finished display, but is also an integral part of the display manufacturing process.

[0012] It would be particularly desirable to have available improved materials for PSA displays that produce particularly small pretilt angles. Preferred materials would be capable of producing lower pretilt angles after the same exposure time and / or at least the same pretilt angles after a shorter exposure time compared to prior art materials. This would allow for shorter display manufacturing times ("takt time") and reduced costs in the manufacturing process.

[0013] Another challenge in the manufacture of PSA displays is the presence and removal of residual amounts of unpolymerized RM after the polymerization step required to create a pretilt angle in the display, which can adversely affect display properties, for example, due to uncontrolled polymerization during display operation.

[0014] Thus, PSA displays known from the prior art often exhibit the undesirable effect of so-called "image sticking" or "image burning", i.e. the image generated in the LC display by temporary addressing of individual pixels remains visible and remains even after the electric field in these pixels has been switched off or other pixels have been addressed.

[0015] For example, the use of LC host mixtures with low VHR can cause image sticking. The UV component of daylight or the display backlight can cause undesirable decomposition of LC molecules, initiating the production of ionic or free radical impurities. These can accumulate, particularly in the electrodes or alignment layers, where they reduce the effective applied voltage. This effect can also be observed in conventional LC displays without polymer components.

[0016] In PSA displays, an additional image-sticking effect caused by the presence of unpolymerized RM is often observed. Uncontrolled polymerization of the remaining RM is initiated by UV light from the environment or backlight. This causes tilt angle changes in switched-on display areas after many address cycles. This can result in transmittance changes in switched-on areas, while the unswitched areas remain unchanged.

[0017] Therefore, when manufacturing PSA displays, it is desirable to ensure that the polymerization of the RM is as complete as possible and to eliminate or minimize the presence of unpolymerized RM in the display. Therefore, there is a need for RM and LC host mixtures that enable or support highly efficient and complete polymerization of the RM. Additionally, reactions with controlled residual amounts of RM are desirable. This could be achieved by providing improved RMs that polymerize more quickly and efficiently than prior art RMs.

[0018] A further challenge that has been observed during the operation of PSA displays is the stability of the pretilt angle. Thus, it has been observed that the pretilt angle generated during display fabrication by polymerizing the RM does not remain constant, but can decrease after subjecting the display to voltage stress during operation. This can adversely affect display performance, for example by increasing dark state transmission and therefore decreasing contrast.

[0019] Another problem to be solved is that prior art RMs often have high melting points and only limited solubility in many commercially used LC mixtures. As a result, these RMs tend to spontaneously crystallize and precipitate from LC mixtures. In addition, the risk of spontaneous polymerization prevents the LC host mixture from being heated to better dissolve the RM, necessitating high solubility even at room temperature. Furthermore, there is a risk of phase separation (chromatographic effect), for example, when filling the LC medium into an LC display, which can significantly impair the display homogeneity. Due to the fact that, in order to reduce the risk of spontaneous polymerization (see above), the LC medium is usually filled into the display at low temperature, this risk of separation is further increased, which has a negative impact on solubility.

[0020] Another problem observed in the prior art is that the use of conventional LC media in LC displays (including, but not limited to, PSA-type displays) often results in the occurrence of mura within the display, especially when the LC medium is filled into the display using one drop filling (ODF). This phenomenon is also known as "ODF mura." Therefore, it would be desirable to provide an LC medium that leads to reduced ODF mura.

[0021] Another problem observed in the prior art is that LC media for use in PSA displays (but not limited to PSA-type displays) often exhibit high viscosity and, as a result, long switching times. To reduce the viscosity and response time of LC media, the prior art has suggested adding LC compounds having alkenyl groups. However, LC media containing alkenyl compounds often exhibit reduced reliability and stability, and it has been observed that the VHR decreases, especially after exposure to UV radiation. For use in PSA displays in particular, photopolymerization of RMs in PSA displays is usually carried out by exposure to UV radiation, which can result in a decrease in the VHR of the LC medium, and this decrease in VHR after exposure to UV radiation is a significant disadvantage.

[0022] The prior art has proposed LC media for use in PSA displays, in which the LC host mixture contains one or more terphenyl compounds to promote polymerization of RM. However, the addition of terphenyl compounds increases the viscosity of the LC host mixture, thereby slowing down the response time. In addition, the addition of terphenyl compounds may lead to reduced reliability and VHR after UV stress in the LC medium.

[0023] It is therefore another problem to provide LC mixtures and LC media for PSA displays which exhibit reduced viscosity and high VHR, while at the same time allowing rapid and complete polymerization of the RM.

[0024] There is therefore a great need for PSA displays which do not exhibit, or exhibit to a lesser extent, the above-mentioned drawbacks and which have improved properties, as well as for LC media and polymerizable compounds for use in such displays.

[0025] There is a great demand for LC mixtures and RMs for use in PSA displays in particular, which simultaneously enable high resistivity over a wide operating temperature range, short response times even at low temperatures, low threshold voltages, low pretilt angles, a large number of grey levels, high contrast and wide viewing angles, high reliability after UV exposure and high VHR values, and, in the case of RMs, low melting points and high solubility in LC host mixtures. For PSA displays intended for mobile applications, it is particularly desirable to have available LC media that exhibit low threshold voltages and high birefringence.

[0026] The present invention is based on the object of providing new suitable materials, in particular RMs, LC host mixtures and LC media containing same, for use in PSA displays, which do not have or have to a reduced extent the disadvantages indicated above.

[0027] In particular the present invention is based on the object of providing an LC medium for use in PSA displays which allows very high resistivity values, high VHR values, high reliability, low threshold voltages, short response times, high birefringence, shows good UV absorption, especially at longer wavelengths, polymerizes the RM contained therein quickly and completely, produces low pretilt angles as quickly as possible, allows high stability of the pretilt even after longer times and / or after UV exposure, reduces or prevents the occurrence of image sticking in displays, reduces or prevents the occurrence of ODF mura in displays.

[0028] Another object of the present invention is to solve the problem of providing LC mixtures and LC media for PSA displays which exhibit reduced viscosity and high VHR while allowing rapid and complete polymerization of the RM.

[0029] The above objects have been achieved in accordance with the present invention by the materials and methods described and claimed in this application.

[0030] It has surprisingly been found that at least some of the above-mentioned problems can be solved by using an LC medium comprising a polymerizable component and an LC host mixture containing compounds of formulae B and Q as disclosed and claimed hereinafter.

[0031] Thus, it has been found that when LC media as disclosed and claimed hereinafter are used in PSA displays, it is possible to reduce the viscosity of the LC host mixture while still maintaining a high VHR, high UV absorption and strong tilt angle generation necessary for rapid and complete polymerization.

[0032] In particular, it has been found that an improvement in viscosity can be achieved by adding a compound of formula B to an LC medium, and an improvement in VHR can be achieved by adding a compound of formula Q to an LC medium. [Prior art documents] [Patent documents]

[0033] [Patent Document 1] European Patent Application Publication No. 1170626 [Patent Document 2] U.S. Patent No. 6,861,107 [Patent Document 3] U.S. Patent No. 7,169,449 [Patent Document 4] U.S. Patent Application Publication No. 2004 / 0191428 [Patent Document 5] U.S. Patent Application Publication No. 2006 / 0066793 [Patent Document 6] U.S. Patent Application Publication No. 2006 / 0103804 [Patent Document 7] U.S. Patent No. 6,177,972 [Non-patent literature]

[0034] [Non-Patent Document 1] T.-J-Chen et al., Jpn.J.Appl.Phys. vol. 45, 2006, pp. 2702-2704 [Non-patent document 2] SHKim, L.-C-Chien, Jpn.J.Appl.Phys.43, 2004, pp. 7643-7647 [Non-patent document 3] Appl.Phys.Lett.1999, Volume 75 (No. 21), Page 3264 [Non-patent document 4] Optics Express 2004, Volume 12 (No. 7), Page 1221 Summary of the Invention [Problem to be solved by the invention]

[0035] The use of the LC medium according to the present invention facilitates a rapid and complete UV photopolymerization reaction at particularly low UV energies and / or longer UV wavelengths in the range of 300-380 nm, especially above 340 nm, which is of considerable advantage to the display manufacturing process. In addition, the use of the LC medium according to the present invention allows for the rapid generation of large and stable pretilt angles, reduces image sticking and ODF mura in displays, leads to high VHR values ​​after UV photopolymerization, and makes it possible to achieve fast response times, low threshold voltages, and high birefringence. [Means for solving the problem]

[0036] The present invention relates to a liquid crystal (LC) medium comprising one or more polymerizable compounds, one or more compounds of formula B and one or more compounds of formula Q.

[0037] [ka] The individual radicals, which may be identical or different at each occurrence in the formula, each have, independently of one another, the following meanings: R 1 , R 2 , R Qalkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which groups may be fluorinated, X Q F, Cl, halogenated alkyl or alkoxy having 1 to 6 C atoms or halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, L 1 , L 2 F or Cl, preferably F, L Q1 ~L Q6 H, F or Cl, preferably H or F, but L Q1 ~L Q6 At least one of is F or Cl, preferably F.

[0038] The present invention further comprises: a polymerizable component A) comprising, preferably consisting of, one or more polymerizable compounds, and a liquid crystal component B) comprising, preferably consisting of, one or more mesogenic or liquid crystal compounds, hereinafter also referred to as "LC host mixture"; A liquid crystal (LC) medium comprising: Component B) relates to a liquid crystal (LC, liquid crystal) medium comprising one or more compounds of formula B and one or more compounds of formula Q as defined above and below.

[0039] The liquid crystal component B) of the LC media according to the invention, hereinafter also called "LC host mixture", preferably contains only LC compounds selected from non-polymerizable low molecular weight compounds such as those of the formulae B and Q, and optionally additives such as polymerization initiators, inhibitors, etc.

[0040] The invention further relates to an LC medium or an LC display as described above and below, in which the polymerizable compounds of component A) have been polymerized.

[0041] The present invention further relates to a method for preparing an LC medium as described above and below, comprising the steps of: The present invention relates to a method comprising the step of mixing one or more compounds of formula B and one or more compounds of formula Q as described above and below, or LC host mixtures or LC components B), with one or more polymerizable compounds and, optionally, further LC compounds and / or additives.

[0042] The invention further relates to the use of the LC medium in LC displays, in particular in PSA displays.

[0043] The present invention further relates to the use of the LC media according to the invention in PSA displays, in particular in PSA displays containing an LC medium, for generating a tilt angle in the LC medium by in situ polymerizing the polymerizable compound(s) of component B) in the PSA display, preferably while applying an electric or magnetic field.

[0044] The present invention further relates to an LC display comprising one or more compounds of formula I or an LC medium according to the invention, which is preferably a PSA display, very preferably a PS-VA, PS-IPS or PS-UB-FFS display.

[0045] The present invention further relates to an LC display comprising one or more compounds of formula I or a polymer obtainable by polymerizing polymerizable component A) as described above, or comprising an LC medium according to the present invention, which is preferably a PSA display, very preferably a PS-VA, PS-IPS or PS-UB-FFS display.

[0046] The present invention further relates to an LC display of the PSA type comprising two substrates, at least one of which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and a layer of an LC medium comprising one or more polymerizable compounds and LC components as described above and below, arranged between the substrates, with the proviso that the polymerizable compounds are polymerized between the substrates of the display.

[0047] The present invention further relates to a method for producing an LC display as described above and below, comprising the steps of filling or otherwise providing between the substrates of the display an LC medium comprising one or more polymerizable compounds as described above and below, and polymerizing the polymerizable compounds.

[0048] The PSA displays according to the invention have two electrodes, preferably in the form of transparent layers, provided on one or both of the substrates. In some displays, such as PS-VA displays, one electrode is provided on each of the two substrates. In other displays, such as PS-IPS or PS-UB-FFS displays, both electrodes are provided on only one of the two substrates.

[0049] In a preferred embodiment, the polymerizable component is polymerized within the LC display while a voltage is applied to the electrodes of the display.

[0050] The polymerizable compound of the polymerizable component is preferably polymerized by photopolymerization, and very preferably by UV photopolymerization. DETAILED DESCRIPTION OF THE INVENTION

[0051] Unless otherwise stated, the polymerizable compounds are selected from achiral compounds.

[0052] As used herein, the terms "active layer" and "switchable layer" refer to a layer in an electro-optical display, e.g., an LC display, that contains one or more types of molecules with structural and optical anisotropy, e.g., LC molecules, that undergo a change in molecular orientation upon application of an external stimulus, such as an electric or magnetic field, resulting in a change in the transparency of the layer for polarized or unpolarized light.

[0053] As used herein, the terms "tilt" and "tilt angle" are understood to mean the tilted orientation of the LC molecules of the LC medium in an LC display (herein preferably a PSA display) relative to the cell surface. Herein, tilt angle means the average angle (less than 90°) between the molecular long axis (LC director) of the LC molecules and the surfaces of the flat, parallel outer plates forming the LC cell. Herein, low values ​​of tilt angle (i.e., large deviations from the 90° angle) correspond to large tilt. A suitable method for measuring tilt angle is given in the examples. Unless otherwise indicated, the tilt angle values ​​disclosed above and below refer to this measurement method.

[0054] As used herein, the terms "reactive mesogen" and "RM" are understood to mean a compound containing a mesogenic or liquid crystalline backbone and one or more functional groups attached to the backbone that are suitable for polymerization, which functional groups are also referred to as "polymerizable groups" or "P".

[0055] Unless otherwise stated, as used herein, the term "polymerizable compound" is understood to mean a polymerizable monomeric compound.

[0056] As used herein, the term "low molecular weight compound" is understood as a term in contrast to "polymeric compound" or "polymer" to mean a compound that is monomeric and / or not prepared by a polymerization reaction.

[0057] As used herein, the term "non-polymerizable compound" is understood to mean a compound that does not contain functional groups suitable for polymerization under conditions normally applied for the polymerization of RMs.

[0058] As used herein, the term "mesogenic group" is known to those skilled in the art and described in the literature and refers to a group that, due to the anisotropy of its attractive and repulsive interactions, essentially contributes to the generation of a liquid crystal (LC) phase in low-molecular-weight or polymeric materials. A compound containing a mesogenic group (mesogenic compound) does not necessarily have an LC phase by itself. It is also possible for a mesogenic compound to exhibit LC phase behavior only after mixing with other compounds and / or polymerization. Typical mesogenic groups are, for example, rigid rod- or disc-shaped units. A review of terms and definitions used in relation to mesogens or LC compounds is given in Pure Appl. Chem. 2001, Vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, Vol. 116, pp. 6340-6368.

[0059] As used herein, the term "spacer group", hereinafter also referred to as "Sp", is known to those skilled in the art and described in the literature, see, for example, Pure Appl. Chem. 2001, vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, vol. 116, pp. 6340-6368. As used herein, the term "spacer group" or "spacer" refers to a flexible group, such as an alkylene group, that connects a mesogenic group and a polymerizable group(s) in a polymerizable mesogenic compound.

[0060] Above and below,

[0061] [ka] represents a trans-1,4-cyclohexylene ring,

[0062] [ka] represents a 1,4-phenylene ring.

[0063] Above and below, "organic group" represents a carbon or hydrocarbon group.

[0064] The term "carbon group" refers to a monovalent or polyvalent organic group containing at least one carbon atom, provided that it either contains no additional atoms (e.g., -C≡C-) or it may contain one or more additional atoms (e.g., carbonyl) such as, for example, N, O, S, B, P, Si, Se, As, Te, or Ge. The term "hydrocarbon group" refers to a carbon group that additionally contains one or more H atoms and may contain one or more heteroatoms such as, for example, N, O, S, B, P, Si, Se, As, Te, or Ge.

[0065] "Halogen" represents F, Cl, Br or I.

[0066] -CO-, -C(=O)- and -C(O)- are carbonyl groups, i.e.

[0067] [ka] Represents.

[0068] The carbon or hydrocarbon group may be saturated or unsaturated. Unsaturated groups are, for example, aryl, alkenyl, or alkynyl groups. The carbon or hydrocarbon group having more than three carbon atoms may be linear, branched, and / or cyclic, and may contain spiro-linked or fused rings.

[0069] The terms "alkyl," "aryl," "heteroaryl," etc. also encompass polyvalent groups such as alkylene, arylene, heteroarylene, etc.

[0070] The term "aryl" refers to an aromatic carbon group or a group derived therefrom. The term "heteroaryl" refers to an "aryl" as defined above containing one or more heteroatoms (preferably selected from N, O, S, Se, Te, Si, and Ge).

[0071] Preferred carbon and hydrocarbon groups are optionally substituted, linear, branched or cyclic alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy, optionally substituted aryl or aryloxy having 5 to 30, preferably 6 to 25 C atoms, or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy having 5 to 30, preferably 6 to 25 C atoms, with the proviso that one or more C atoms may be replaced by a heteroatom, preferably selected from N, O, S, Se, Te, Si and Ge.

[0072] More preferred carbon and hydrocarbon groups are C1-C 20 Alkyl, C2-C 20 Alkenyl, C2-C 20 Alkynyl, C3-C 20 Allyl, C4~C 20 Alkyldienyl, C4-C 20 Polyenyl, C6-C 20 Cycloalkyl, C4-C 15 Cycloalkenyl, C6-C 30 Aryl, C6-C 30 Alkylaryl, C6-C 30 Aryl alkyl, C6-C 30 Alkylaryloxy, C6-C 30 Arylalkyloxy, C2-C 30 Heteroaryl, C2-C 30 It is heteroaryloxy.

[0073] C1~C 12 Alkyl, C2-C 12 Alkenyl, C2-C 12 Alkynyl, C6-C 25 Aryl and C2-C 25 Heteroaryl is particularly preferred.

[0074] Further preferred carbon and hydrocarbon groups are alkyl, linear, branched or cyclic, having 1 to 20, preferably 1 to 12, C atoms, which are unsubstituted or mono- or polysubstituted by F, Cl, Br, I or CN, provided that one or more non-adjacent CH groups are each independently of one another -C(R x )=C(R x )-, -C≡C-, -N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, or -O-CO-O-.

[0075] R x preferably represents H, F, Cl, CN, a linear, branched or cyclic alkyl chain having 1 to 25 C atoms (with the proviso that in addition, one or more non-adjacent C atoms may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and with the proviso that one or more H atoms may be replaced by F or Cl), or an optionally substituted aryl or aryloxy group having 6 to 30 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 30 C atoms.

[0076] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecanyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, and the like.

[0077] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, and the like.

[0078] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, and the like.

[0079] Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, and the like.

[0080] Preferred amino groups include, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, and the like.

[0081] Aryl and heteroaryl groups can be monocyclic or polycyclic, i.e., they can contain one ring (e.g., phenyl) or two or more rings, and the groups can be fused (e.g., naphthyl) or covalently linked (e.g., biphenyl) or contain a combination of fused and linked rings. Heteroaryl groups preferably contain one or more heteroatoms selected from O, N, S, and Se.

[0082] Particularly preferred are mono-, bi- or tricyclic aryl groups having 6 to 25 C atoms and mono-, bi- or tricyclic heteroaryl groups having 5 to 25 ring atoms, which may contain fused rings and may be substituted.Furthermore, 5-, 6- or 7-membered aryl and heteroaryl groups are preferred, provided that in addition, one or more CH groups may be replaced by N, S or O, in such a way that the O and / or S atoms are not directly linked to one another.

[0083] Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1':3',1"]terphenyl-2'-yl, naphthyl, anthracene, binaphthyl, phenanthrene, 9,10-dihydrophenanthrene, pyrene, dihydropyrene, chrysene, perylene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene, and the like.

[0084] Preferred heteroaryl groups are, for example, pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4- Five-membered rings such as thiadiazole, 1,2,5-thiadiazole, and 1,3,4-thiadiazole; six-membered rings such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, and 1,2,3,5-tetrazine; or indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, prilus benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoiazole, naphthimidazole, phenanthroimidazole, pyridimidazole, pyrazineimidazole, quinoxalineimidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoiazole fused groups such as isoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiadiazothiophene; or combinations of these groups.

[0085] The aryl and heteroaryl groups mentioned above and below may also be substituted with alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or further aryl or heteroaryl groups.

[0086] (Non-aromatic) alicyclic and heterocyclic groups include both saturated rings, i.e., those containing exclusively single bonds, and also partially unsaturated rings, i.e., those which may also contain multiple bonds. Heterocyclic rings preferably contain one or more heteroatoms selected from Si, O, N, S and Se.

[0087] (Non-aromatic) alicyclic and heterocyclic groups may be monocyclic, i.e., containing only one ring (e.g., cyclohexane), or polycyclic, i.e., containing multiple rings (e.g., decahydronaphthalene or bicyclooctane). Saturated groups are particularly preferred. Furthermore, monocyclic, bicyclic, or tricyclic groups having 5 to 25 ring atoms are preferred, which may contain fused rings and may be substituted. Furthermore, 5-, 6-, 7-, or 8-membered carbocyclic groups are preferred, provided that in addition, one or more C atoms may be replaced by Si, and / or one or more CH groups may be replaced by N, and / or one or more non-adjacent CH groups may be replaced by -O- and / or -S-.

[0088] Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, and pyrrolidine; 6-membered groups such as cyclohexane, silynan, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, and piperidine; 7-membered groups such as cycloheptane; and fused groups such as tetrahydronaphthalene, decahydronaphthalene, indane, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, and octahydro-4,7-methanoindan-2,5-diyl.

[0089] Preferred substituents are, for example, solubility-promoting groups such as alkyl or alkoxy, electron-withdrawing groups such as fluorine, nitro or nitrile, or substituents for increasing the glass transition temperature (Tg) in the polymer, especially bulky groups such as, for example, t-butyl or optionally substituted aryl groups.

[0090] Preferred substituents, hereinafter also referred to as "L", are F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )2, -C(=O)Y 1 , -C(=O)R x , -N(R x )2, linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, each having 1 to 25 C atoms (provided that one or more H atoms may be replaced by F or Cl), optionally substituted silyl having 1 to 20 Si atoms, optionally substituted aryl having 6 to 25, preferably 6 to 15, C atoms, However, R x represents H, F, Cl, CN, linear, branched or cyclic alkyl having 1 to 25 C atoms, with the proviso that one or more non-adjacent CH groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly linked to one another, with the proviso that one or more H atoms may be replaced by F, Cl, P- or Sp-, respectively, and Y 1 represents a halogen.

[0091] "Substituted silyl or aryl" preferably includes halogen, -CN, R 0 , -OR 0 , -CO-R 0 , -CO-OR 0 , -O-CO-R 0 or -O-CO-OR 0 where R 0 represents H or alkyl having 1 to 20 C atoms.

[0092] Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, and also phenyl.

[0093] [ka] wherein L has one of the meanings given above.

[0094] The polymerizable group P is, for example, a group suitable for polymerization reactions, such as free-radical or ionic chain polymerization, polyaddition or polycondensation, or for polymer-analogous reactions, such as addition or condensation onto the main chain. Groups for chain polymerization, especially those containing a C=C double bond or a -C≡C- triple bond, and groups suitable for ring-opening polymerization, such as, for example, oxetane or epoxide groups, are particularly preferred.

[0095] The preferred group P is CH2=CW 1 -CO-O-, CH2=CW 1 -CO-,

[0096] [ka] CH2=CW 2 -(O) k3 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW 2 W 3 -, HS-CW 2 W 3 -, HW 2 N-, HO-CW 2 W 3 -NH-, CH2=CW 1-CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si—, wherein W 1 denotes H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, and W 2 and W 3 each independently of one another denotes H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 carbon atoms, W 7 and W 8 each independently represent H, Cl, alkyl having 1 to 5 C atoms; Phe represents 1,4-phenylene as defined above which may be substituted with one or more groups L other than P-Sp-; k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer of 1 to 10.

[0097] Particularly preferred groups P are CH2=CW 1 -CO-O-, CH2=CW 1 -CO-,

[0098] [ka] CH2=CW 2 -O-, CH2=CW 2 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1-CO-NH-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH- and W 4 W 5 W 6 Si—, wherein W 1 denotes H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, and W 2 and W 3 each independently of one another denotes H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 carbon atoms, W 7 and W 8 each independently represent H, Cl, or alkyl having 1 to 5 C atoms; Phe represents 1,4-phenylene; k1, k2, and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer of 1 to 10.

[0099] Very particularly preferred groups P are CH2=CW 1 -CO-O-, in particular CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, further CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-,

[0100] [ka] is selected from the group consisting of:

[0101] More preferably, the polymerizable group P is selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably acrylate or methacrylate.

[0102] When Sp is different from a single bond, Sp is preferably of the formula Sp"-X" so that each group P-Sp- corresponds to the formula P-Sp"-X"-, where Sp" and X" have the following meanings:

[0103] Sp" represents alkylene having 1 to 20, preferably 1 to 12, C atoms, which may be mono- or polysubstituted by F, Cl, Br, I or CN, provided that in addition, one or more non-adjacent CH groups are each independently of one another -O-, -S-, -NH-, -N(R 0 )-, -Si(R 0 R 00 )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00 )-CO-O-, -O-CO-N(R 0 )-, -N(R 0 )-CO-N(R 00 )-, -CH=CH- or -C≡C-; “X” is -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R 0 )-, -N(R 0 )-CO-, -N(R 0 )-CO-N(R 00 )-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 0 -, -CY 2 =CY 3 represents -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond; R 0 and R 00 each independently represent H or alkyl having 1 to 20 C atoms, Y 2 and Y 3 each independently represents H, F, Cl or CN, X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, or -CO-NR 0 -, -NR 0 -CO-, -NR 0 -CO-NR 00 - or a single bond.

[0104] Exemplary spacer groups Sp and -Sp"-X"- include, for example, -(CH2) p1 -, -(CH2CH2O) q1 -CH2CH2-, -CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2- or -(SiR 0 R 00 -O) p1 In the formula, p1 is an integer of 1 to 12, q1 is an integer of 1 to 3, and R 0 and R 00 has the meaning given above.

[0105] Particularly preferred groups Sp and -Sp"-X"- are -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-O-, where p1 and q1 have the meanings given above.

[0106] Particularly preferred radicals Sp" are, in their respective linear forms, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

[0107] The compounds of formula B are preferably selected from formula B1.

[0108] [ka] where alkyl represents a linear alkyl group having 1 to 6 C atoms and (O) represents an oxygen atom or a single bond. Highly preferred are compounds of formula B1 in which both groups (O) represent an oxygen atom and alkyl is methyl, ethyl, propyl, butyl, pentyl or hexyl, preferably linear.

[0109] The proportion of compounds of the formula B or B1 in the LC medium, preferably in component B) of the LC medium, is preferably 0.5 to 20%, very preferably 1 to 15%, most preferably 1 to 10%.

[0110] In another preferred embodiment of the invention, the proportion of compounds of formula B or B1 in the LC medium, preferably in component B) of the LC medium, is 3% or more, more preferably 4% or more. In another preferred embodiment of the invention, the proportion of compounds of formula B or B1 in the LC medium, preferably in component B) of the LC medium, is 20% or less, more preferably 15% or less. The proportion of compounds of formula B or B1 in the LC medium, preferably in component B) of the LC medium, is very preferably 3-20%, most preferably 4-15%.

[0111] Preferably the LC medium contains 1 to 5, preferably 1, 2 or 3 compounds of formula B or B1.

[0112] Preferred compounds of formula Q, Q1 and Q2 are Q3 and L Q4 is F. Further preferred compounds of formula Q, Q1 and Q2 are those in which L Q3 , L Q4 and L Q1 and L Q2 One or two of these are F.

[0113] Further preferred compounds of formula Q are X Q represents F or OCF3, very preferably F.

[0114] The compounds of formula Q are preferably selected from the following sub-formulae:

[0115] [ka] In the formula, R Q has one of the meanings of formula Q or one of the preferred meanings thereof given above and below, and is preferably ethyl, n-propyl or n-butyl.

[0116] Preferred compounds of formula Q, Q1 and Q2 are R Q denotes straight-chain alkyl having 2 to 6 C atoms, very preferably ethyl, n-propyl or n-butyl.

[0117] Compounds of formula Q1, in particular R Q is particularly preferably n-propyl.

[0118] The proportion of compounds of the formula Q in the LC medium, preferably in component B) of the LC medium, is preferably from >0 to 5%, very preferably from 0.05 to 2%, most preferably from 0.1 to 1%.

[0119] Preferably the LC medium contains 1 to 5, preferably 1 or 2, compounds of formula Q.

[0120] The use of LC host mixtures comprising compounds of formulae B and Q in conjunction with the use of polymerizable components which preferably comprise di- and / or tri-reactive RMs in LC media according to the invention leads to advantageous properties in PSA displays. In particular, one or more of the following advantages can be achieved:

[0121] Good UV absorption at longer wavelengths Rapid and complete polymerization of RM Rapid generation of particularly low pretilt angles at low UV energies and / or longer UV wavelengths, High UV absorption, Improved UV stability, High pretilt angle stability after UV exposure, -Reduction of image sticking, -Reduction of ODF unevenness, High reliability and high VHR values ​​after UV exposure and / or heat treatment, High birefringence, - Viscosity reduction, Faster response time.

[0122] It has surprisingly been found that in particular in LC media according to the invention which contain higher amounts of a compound of formula B, preferably at least 3% or even 4%, the VHR can be improved more significantly, for example the VHR can be maintained at a high level even after polymerization of the polymerizable compounds by adding a compound of formula Q. Since the addition of higher amounts of a compound of formula B leads to a more significant improvement (i.e. reduction) of the viscosity, the addition of both a compound of formula B and a compound of formula Q allows the advantages of a high VHR and a low viscosity to be combined.

[0123] Furthermore, the LC media according to the invention show high absorption at longer UV wavelengths, which allows the use of longer UV wavelengths for the polymerization, which is advantageous for the display manufacturing process.

[0124] The polymerizable compound is preferably selected from formula I:

[0125] [ka] In the formulae, the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another: R a and R b P, P-Sp-, H, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, SF5 or linear or branched alkyl having 1 to 25 C atoms, provided that in addition one or more non-adjacent CH2 groups are each independently connected to one another such that O and / or S atoms are not directly linked to one another, -C(R 0 )=C(R 00 )-, -C≡C-, -N(R 00 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, provided that in addition one or more H atoms may be replaced by F, Cl, Br, I, CN, P or P-Sp-, provided that B 1 and / or B. 2 contains saturated C atoms, and R a and / or R b may represent a group spiro-linked to this saturated C atom, However, the group R a and R b at least one of which represents or contains the group P or P-Sp-, P polymerizable group, Sp a spacer group or a single bond; B 1 and B 2 an aromatic, heteroaromatic, alicyclic or heterocyclic group, preferably having 4 to 25 ring atoms, which may also contain fused rings, which group is unsubstituted or mono- or polysubstituted by L, Z b -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1-, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, CR 0 R 00 or a single bond, R 0 and R 00 each independently represents H or alkyl having 1 to 12 C atoms, m represents 0, 1, 2, 3 or 4; n1 represents 1, 2, 3 or 4, LP, P-Sp-, OH, CH2OH, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )2, -C(=O)Y 1 , -C(=O)R x , -N(R x ) 2, optionally substituted silyl, optionally substituted aryl having 6 to 20 C atoms or linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, wherein in addition one or more H atoms may be replaced by F, Cl, P or P-Sp-, P and Sp have the meanings given above, Y 1 represents a halogen, R x P, P-Sp-, H, halogen, linear, branched or cyclic alkyl having 1 to 25 C atoms (provided that in addition, one or more non-adjacent CH groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not directly linked to each other, and in addition, one or more H atoms may be replaced by F, Cl, P or P-Sp-), an optionally substituted aryl or aryloxy group having 6 to 40 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 C atoms.

[0126] Particularly preferred compounds of formula I are B 1 and B 2are each independently 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl, naphthalene-2,6-diyl, phenanthrene-2,7-diyl, 9,10-dihydro-phenanthrene-2,7-diyl, anthracene-2,7-diyl, fluorene-2,7-diyl, coumarin, flavone (in addition, one or more CH groups in these groups may be replaced by N), cyclohexane-1,4-diyl (in addition, one or more non-adjacent CH groups may be replaced by O and / or S), 1 ,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indan-2,5-diyl or octahydro-4,7-methanoindan-2,5-diyl, all of which groups may be unsubstituted or mono- or polysubstituted by L as defined above.

[0127] Particularly preferred compounds of formula I are B 1 and B 2 each independently represents 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl or naphthalene-2,6-diyl.

[0128] Highly preferred compounds of formula I are selected from the following formulae:

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] [ka] In the formulae, the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another: P 1 , P 2 , P 3 vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane or epoxy groups, Sp 1 , Sp 2 , Sp 3 a single bond or a spacer group, but in addition, if any group P is present 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 -At least one of R aa one or more groups P 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 - is R aa It can be expressed as R aa H, F, Cl, CN, or linear or branched alkyl having 1 to 25 C atoms (provided that in addition one or more non-adjacent CH groups are present, each independently of the other, in such a way that O and / or S atoms are not directly linked to each other), C(R 0 )=C(R 00 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, provided that in addition one or more H atoms may be replaced by F, Cl, CN or P 1 -Sp 1-), particularly preferably linear or branched, mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, with the proviso that alkenyl and alkynyl groups have at least 2 C atoms and branched groups have at least 3 C atoms, R 0 , R 00 H or alkyl having 1 to 12 C atoms, R y and R z H, F, CH3 or CF3, X 1 , X 2 , X 3 -CO-O-, -O-CO- or a single bond, Z 1 -O-, -CO-, -C(R y R z )- or -CF2CF2-, Z 2 , Z 3 -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2- or -(CH2) n -, where n is 2, 3, or 4; LF, Cl, CN or alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, which may be linear or branched and monofluorinated or polyfluorinated, L', L" H, F or Cl, r 0, 1, 2, 3 or 4, s 0, 1, 2 or 3, t 0, 1 or 2, x 0 or 1.

[0133] Compounds of formula M2 and M13, in particular those containing exactly two polymerizable groups P 1 and P 2 Highly preferred are direactive compounds containing:

[0134] Furthermore, compounds M15 to M31, in particular M17, M18, M19, M22, M23, M24, M25, M26, M30 and M31, in particular those containing exactly three polymerizable groups P 1 , P 2 and / or P 3 Preferred are trireactive compounds containing

[0135] In the compounds of formulae M1 to M31, the group

[0136] [ka] and wherein L, identically or differently, in each occurrence has one of the meanings given above and below, preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, OCH3, COCH3, OCF3 or P-Sp-, more preferably F, Cl, CH3, OCH3, COCH3 or OCF3, in particular F or CH3.

[0137] Preferred compounds of formulae M1 to M30 are P 1 , P 2 and P 3 represents an acrylate, methacrylate, oxetane or epoxy group, very preferably an acrylate or methacrylate group.

[0138] Further preferred compounds of formulae M1 to M31 are Sp 1 , Sp 2 and Sp 3 is a single bond.

[0139] Further preferred compounds of formulae M1 to M31 are Sp 1 , Sp 2 and Sp 3One of them is a single bond, and Sp 1 , Sp 2 and Sp 3 The other one is different from a single bond.

[0140] Further preferred compounds of the formulae M1 to M31 are those in which the group Sp is different from a single bond 1 , Sp 2 and Sp 3 -(CH2) s1 represents -X"-, where s1 is an integer of 1 to 6, preferably 2, 3, 4, or 5, and X" is a linkage to a benzene ring and is -O-, -O-CO-, -CO-O, -O-CO-O-, or a single bond.

[0141] Particularly preferred are LC media which comprise one, two or three polymerisable compounds of formula I.

[0142] Preferably the proportion of compounds of formula I in the LC medium is between 0.01 and 5%, very preferably between 0.05 and 1%, most preferably between 0.1 and 0.5%.

[0143] It has been observed that combining polymerizable compounds of formulae M1-M31 with compounds of formulae B and Q results in favorable behavior of the LC medium, achieving rapid and complete polymerization, rapid generation of low pretilt that is stable even after UV exposure, as well as high reliability after UV exposure and high UVR values, along with high birefringence. Additionally, the LC medium exhibits high absorption at longer UV wavelengths, allowing the use of such longer UV wavelengths for polymerization, which is advantageous for the display manufacturing process.

[0144] To produce a PSA display, polymerizable compounds contained in the LC medium are polymerized or crosslinked (if one compound contains more than one polymerizable group) by in situ polymerization in the LC medium between the substrates of the LC display, optionally with application of a voltage to the electrodes.

[0145] The structure of the PSA display according to the present invention corresponds to the usual configuration of PSA displays as described in the prior art cited at the beginning. A configuration without protrusions is preferred, in particular one in which the electrode on the color filter side is unstructured and only the electrode on the TFT side has slits. A particularly suitable and preferred electrode structure for PS-VA displays is described, for example, in US Patent Application Publication No. 2006 / 0066793.

[0146] A preferred PSA type LC display of the present invention is a first substrate including pixel electrodes defining pixel areas, the pixel electrodes being connected to switch elements disposed in each pixel area and optionally having a micro-slit pattern, and optionally a first alignment layer disposed on the pixel electrodes; a second substrate including a conventional electrode layer, and an optional second alignment layer, which may be disposed on the entire portion of the second substrate facing the first substrate; a LC layer comprising an LC medium comprising a polymerizable component A and a liquid crystal component B as described above and below (wherein the polymerizable component A may be polymerized), and disposed between first and second substrates; Includes.

[0147] The first and / or second alignment layers control the alignment direction of the LC molecules in the LC layer. For example, in a PS-VA display, the alignment layers are selected to align the LC molecules in a homeotropic (or vertical) orientation (i.e., perpendicular to the surface) or tilted orientation. Such alignment layers can comprise, for example, polyimides, which may be rubbed or prepared by photoalignment.

[0148] The LC layer with the LC medium can be placed between the substrates of the display by methods commonly used in display manufacturing, for example the so-called one drop filling (ODF) method. The polymerizable components of the LC medium are then polymerized, for example by UV photopolymerization. Polymerization can be carried out in one step or in two or more steps.

[0149] PSA displays may include additional elements such as color filters, black matrices, passivation layers, optical retardation layers, transistor elements for addressing individual pixels, all of which are known to those skilled in the art and can be used without the exercise of patentable skill.

[0150] The electrode structure can be designed by those skilled in the art depending on the type of display, for example, to generate two, four or more different tilt alignment directions for PS-VA displays, electrodes with slits and / or ridges or protrusions can be provided to induce multi-domain alignment of the LC molecules.

[0151] Upon polymerization, the polymerizable compound forms a crosslinked polymer, which induces a certain pretilt of the LC molecules in the LC medium. Without wishing to be bound by any particular theory, it is believed that at least a portion of the crosslinked polymer formed by the polymerizable compound phase separates or precipitates from the LC medium, forming a polymer layer on the substrate or electrodes or alignment layers provided thereon. Microscopic measurements (SEM and AFM, etc.) confirmed that at least a portion of the formed polymer accumulated at the LC / substrate interface.

[0152] The polymerization can be carried out in a single step, or it is also possible to first carry out the polymerization in a first step, optionally with the application of a voltage, to generate a pretilt angle, followed by a second polymerization step in which the compounds that did not react in the first step are polymerized or crosslinked without the application of a voltage ("final cure").

[0153] Suitable and preferred methods of polymerization are, for example, thermal or photopolymerization, preferably photopolymerization, especially UV-induced photopolymerization, which can be achieved by exposing the polymerizable compound to UV radiation.

[0154] One or more polymerization initiators can be added to the LC medium. Suitable polymerization conditions and the appropriate type and amount of initiator are known to those skilled in the art and are described in the literature. For example, commercially available photoinitiators Irgacure 651®, Irgacure 184®, Irgacure 907®, Irgacure 369®, or Darocure 1173® (Ciba) are suitable for free-radical polymerization. When a polymerization initiator is used, the proportion of initiator is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.

[0155] The polymerizable compound according to the present invention is also suitable for polymerization without initiator, which has significant advantages, such as lower material costs and, in particular, less contamination of the LC medium by residual amounts of initiator or its degradation products.In this way, polymerization can also be carried out without adding initiator.Therefore, in a preferred embodiment, the LC medium does not contain a polymerization initiator.

[0156] The LC medium may also contain one or more stabilizers, for example, to prevent undesired spontaneous polymerization of the RM during storage or transportation. Suitable types and amounts of stabilizers are known to those skilled in the art and are described in the literature. Commercially available stabilizers, such as Irganox® 1076 from the Irganox® series (Ciba), are particularly suitable. When a stabilizer is used, the proportion of the stabilizer is preferably 10 to 500,000 ppm, particularly preferably 50 to 50,000 ppm, based on the total amount of the RM or polymerizable component (component A).

[0157] The polymerizable compounds of formula I exhibit particularly good UV absorption and are therefore particularly suitable for methods of preparing PSA displays comprising one or more of the following features: exposing the polymerizable medium to UV light within the display in a two-step process including a first UV exposure step ("UV-1 step") to generate the tilt angle and a second UV exposure step ("UV-2 step") to complete the polymerization; The polymerizable medium is exposed in the display to UV light produced by energy-saving UV lamps (also known as "green UV lamps"). These lamps are characterized by a relatively low intensity (1 / 100 to 1 / 10 of that of conventional UV lamps) in the absorption spectrum between 300 and 380 nm, and are preferably used in the UV2 step, but can also be used in the UV1 step if high intensities need to be avoided; To avoid exposure to short wavelength UV light in the PS-VA process, the polymerizable medium is exposed in the display to UV light generated by a UV lamp with an emission spectrum shifted to longer wavelengths (preferably 340 nm or longer).

[0158] Either using lower intensity or shifting to longer wavelength UV protects the organic layers from damage that can be caused by UV light.

[0159] Preferred embodiments of the present invention relate to methods for preparing the PSA displays described above and below, comprising one or more of the following features: exposing the polymerizable LC medium to UV light in two steps, including a first UV exposure step ("UV-1 step") to generate a tilt angle and a second UV exposure step ("UV-2 step") to complete the polymerization; The polymerizable LC medium is illuminated at 0.5 mW / cm within the wavelength range of 300-380 nm. 2 ~10mW / cm 2 (Preferably, this UV lamp is used in the UV2 step and can also be used in the UV1 step); The polymerizable LC medium is exposed to UV light having a wavelength of 340 nm or more and preferably 400 nm or less.

[0160] This preferred method can be carried out, for example, by using a desired UV lamp or a bandpass filter and / or cutoff filter that substantially transmits UV light having the desired wavelength and substantially blocks light having undesired wavelengths. For example, if irradiation with UV light having a wavelength λ of 300 to 400 nm is desired, UV exposure can be carried out using a wide bandpass filter that substantially transmits wavelengths λ greater than 300 nm and less than 400 nm. If irradiation with UV light having a wavelength λ greater than 340 nm is desired, UV exposure can be carried out using a cutoff filter that substantially transmits wavelengths λ greater than 340 nm.

[0161] "Substantially transmit" means that the filter transmits a majority of incident light of a desired wavelength, preferably at least 50% intensity. "Substantially block" means that the filter does not transmit a majority of incident light of undesired wavelengths, preferably at least 50% intensity. "Desired (undesired) wavelength" means, for example, in the case of a bandpass filter, wavelengths within (outside) a given λ range, and in the case of a cutoff filter, wavelengths above (below) a given λ value.

[0162] This preferred method allows for the manufacture of displays using longer wavelength UV, thereby reducing or avoiding the harmful and damaging effects of the short wavelength component of UV light.

[0163] The UV irradiation energy is generally 6 to 100 J, depending on the conditions of the manufacturing process.

[0164] Preferably, the LC medium according to the present invention consists essentially of the polymerizable component A) and the LC component B) (or LC host mixture) as described above and below. However, the LC medium may additionally comprise one or more further components or additives, preferably selected from the following list, which includes, but is not limited to: comonomers, chiral dopants, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricants, dispersants, hydrophobizing agents, adhesives, flow improvers, antifoaming agents, degassing agents, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments and nanoparticles.

[0165] The polymerizable component A) is a compound of formula I * LC media consisting only of polymerizable compounds of the formula (I) are preferred.

[0166] In another preferred embodiment, formula I * In addition to the compounds of the present invention, polymerizable component A) preferably contains one or more further polymerizable compounds ("comonomers") selected from RM.

[0167] Preferably the proportion of polymerizable component A) in the LC medium is from >0 to <5%, very preferably from >0 to <1%, most preferably from 0.01 to 0.5%.

[0168] Preferably the proportion of LC component B) in the LC medium is from 95 to less than 100%, very preferably from 99 to less than 100%.

[0169] In addition to a polymerizable component A) as described above, the LC medium according to the present invention comprises an LC component B) or LC host mixture which comprises one or more, preferably two or more LC compounds selected from non-polymerizable low molecular weight compounds, which LC compounds are selected such that they are stable and / or unreactive towards polymerization reactions under the conditions applied for the polymerization of the polymerizable compound.

[0170] Examples of these compounds are compounds of formulae B and Q above.

[0171] Preference is given to LC media in which the LC component B) or the LC host mixture has a nematic LC phase and preferably no chiral liquid crystal phase.

[0172] Furthermore, achiral compounds of the formula I and LC media in which the compounds of components A and / or B are selected exclusively from the group consisting of achiral compounds are preferred.

[0173] The LC component B) or LC host mixture is preferably a nematic LC mixture.

[0174] In a preferred embodiment of the invention, the LC component B) of the LC medium or LC host mixture comprises, in addition to the compound of formula A, one or more further mesogenic or LC compounds (hereinafter referred to as "alkenyl compounds") containing a linear, branched or cyclic alkenyl group, provided that said alkenyl group is stable to polymerization reactions under the conditions used for the polymerization of the polymerizable compounds contained in the LC medium.

[0175] These further alkenyl compounds are preferably selected from the formulae AN and AY.

[0176] [ka] In the formulae, the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another:

[0177] [ka]

[0178] [ka]

[0179] [ka] R A1Alkenyl having 2 to 9 carbon atoms, when at least one of rings X, Y and Z represents cyclohexenyl, and R A2 One of the meanings of R A2 alkyl having 1 to 12 C atoms, provided that in addition one or two non-adjacent CH groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO-, such that the O atoms are not directly linked to one another; Z x -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CHO-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CHO- or a single bond, preferably a single bond, L 1~4 H, F, Cl, OCF3, CF3, CH3, CH2F or CHF2H, preferably H, F or Cl, x 1 or 2, z 0 or 1.

[0180] Preferred compounds of formula AN and AY are A2 is selected from ethenyl, propenyl, butenyl, pentenyl, hexenyl and heptenyl.

[0181] Further preferred compounds of formula AN and AY are 1 and L 2 represents F or L 1 and L 2 one of which represents F and the other represents Cl, and L 3 and L 4 represents F or L 3 and L 4 One of them represents F and the other represents Cl.

[0182] The compounds of formula AN are preferably selected from the following sub-formulae:

[0183] [ka]

[0184] [ka] During the ceremony, Alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 carbon atoms, alkenyl and alkenyl * each independently represent a straight-chain alkenyl group having 2 to 7 carbon atoms. * preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0185] Highly preferred compounds of formula AN are selected from the following sub-formulae:

[0186] [ka] During the ceremony, m represents 1, 2, 3, 4, 5 or 6; i represents 0, 1, 2 or 3; R b1 is H, CH3 or C2H5.

[0187] Very particularly preferred compounds of formula AN are selected from the following sub-formulae:

[0188] [ka] Compounds of formula AN1a2, AN1a5, AN6a1 and AN6a2 are most preferred.

[0189] The compounds of formula AY are preferably selected from the following sub-formulae:

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193] [ka] During the ceremony, Alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 carbon atoms, alkenyl and alkenyl * each independently represent a straight-chain alkenyl group having 2 to 7 carbon atoms. * preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0194] Highly preferred compounds of formula AY are selected from the following sub-formulae:

[0195] [ka] During the ceremony, m and n each independently represent 1, 2, 3, 4, 5, or 6; and Alkenyl represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0196] The LC medium preferably does not contain compounds containing terminal vinyloxy groups (-O-CH=CH2), in particular R A1 or R A2 does not include compounds of formula AN or AY in which represents or contains a terminal vinyloxy group (-O-CH=CH2).

[0197] In a preferred embodiment, the LC medium contains an LC component B) or an LC host mixture based on compounds with negative dielectric anisotropy. Such LC media are particularly suitable for use in PS-VA and PS-UB-FFS displays. Particularly preferred embodiments of such LC media and the corresponding LC component B) or LC host mixture are those described below under items a) to y).

[0198] a) LC medium or LC host mixtures comprising one or more compounds of formula CY and / or PY.

[0199] [ka] During the ceremony, a represents 1 or 2, b represents 0 or 1;

[0200] [ka] R 1 and R 2 each independently represent alkyl having 1 to 12 C atoms (provided that in addition, one or two non-adjacent CH groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly linked to one another), preferably alkyl or alkoxy having 1 to 6 C atoms, Z x and Z yeach independently represent -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CHO-, -OCH2-, -CO-O-, -O-CO-, -CF4-, -CF=CF-, -CH=CH-CHO- or a single bond, preferably a single bond; L 1~4 each independently represents F, Cl, OCF3, CF3, CH3, CH2F, or CHF2.

[0201] Preferably, L 1 and L 2 Both represent F, or L 1 and L 2 One of them represents F and the other represents Cl, or L 3 and L 4 Both represent F, or L 3 and L 4 One of them represents F and the other represents Cl.

[0202] The compound of formula CY is preferably selected from the group consisting of the following subformulae:

[0203] [ka]

[0204] [ka]

[0205] [ka]

[0206] [ka]

[0207] [ka] In the formula, a represents 1 or 2, and alkyl and alkyl* each independently represent a linear alkyl group having 1 to 6 carbon atoms, alkenyl represents a linear alkenyl group having 2 to 6 carbon atoms, and (O) represents an oxygen atom or a single bond. Alkenyl preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH-, or CH3-CH=CH-(CH2)2-.

[0208] The compounds of formula PY are preferably selected from the group consisting of the following subformulae:

[0209] [ka]

[0210] [ka]

[0211] [ka] In the formula, alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 carbon atoms, alkenyl represents a linear alkenyl group having 2 to 6 carbon atoms, and (O) represents an oxygen atom or a single bond. Alkenyl preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH-, or CH3-CH=CH-(CH2)2-.

[0212] b) LC medium or LC host mixtures comprising one or more compounds of the following formula:

[0213] [ka] wherein the individual groups have the following meanings:

[0214] [ka]

[0215] [ka] R 3 and R 4 each independently represent alkyl having 1 to 12 C atoms, provided that in addition, one or two non-adjacent CH groups may be replaced by -O-, -CH=CH-, -CO-, -O-CO- or -CO-O-, in such a way that the O atoms are not directly linked to one another, Z y represents -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CHCHO- or a single bond, preferably a single bond.

[0216] The compound of formula ZK is preferably selected from the group consisting of the following subformulae:

[0217] [ka] In the formula, alkyl and alkyl * each independently represent a straight-chain alkyl group having 1 to 6 C atoms, and alkenyl represents a straight-chain alkenyl group having 2 to 6 C atoms. Alkenyl preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0218] Compounds of formula ZK1 are particularly preferred.

[0219] Particularly preferred compounds of formula ZK are selected from the following sub-formulae:

[0220] [ka] In the formula, the propyl, butyl and pentyl groups are linear groups.

[0221] Compounds of formula ZK1a are most preferred.

[0222] c) LC medium or LC host mixtures comprising one or more compounds of the following formula:

[0223] [ka] In the formula, the individual radicals, identical or different, at each occurrence have the following meanings: R 5 and R 6 each independently represent alkyl having 1 to 12 C atoms (provided that in addition, one or two non-adjacent CH groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly linked to one another), preferably alkyl or alkoxy having 1 to 6 C atoms,

[0224] [ka]

[0225] [ka] and, e represents 1 or 2.

[0226] The compound of formula DK is preferably selected from the group consisting of the following subformulae:

[0227] [ka]

[0228] [ka] In the formula, alkyl and alkyl * each independently represent a straight-chain alkyl group having 1 to 6 C atoms, and alkenyl represents a straight-chain alkenyl group having 2 to 6 C atoms. Alkenyl preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0229] d) LC media or LC host mixtures comprising one or more compounds of the following formula:

[0230] [ka] wherein the individual groups have the following meanings:

[0231] [ka] At least one ring F is different from cyclohexylene; f represents 1 or 2; R 1 and R 2 each independently represent alkyl having 1 to 12 C atoms, provided that in addition, one or two non-adjacent CH groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly linked to one another, Z x represents -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CHO-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CHCHO- or a single bond, preferably a single bond; L 1 and L 2each independently represents F, Cl, OCF3, CF3, CH3, CH2F, or CHF2.

[0232] Preferably, the group L 1 and L 2 both represent F or a group L 1 and L 2 One of them represents F and the other represents Cl.

[0233] The compound of formula LY is preferably selected from the group consisting of the following subformulae:

[0234] [ka]

[0235] [ka]

[0236] [ka] In the formula, R 1 has the meaning indicated above, alkyl represents a linear alkyl group having 1 to 6 C atoms, (O) represents an oxygen atom or a single bond, and v represents an integer of 1 to 6. R 1 is preferably a linear alkyl having 1 to 6 C atoms or a linear alkenyl having 2 to 6 C atoms, in particular CH3, C2H5, n-C3H7, n-C4H9, n-C5H 11 , CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0237] e) LC medium or LC host mixtures comprising one or more compounds of the following formula:

[0238] [ka] In the formula, the individual radicals are identical or different at each occurrence and each have, independently of one another, the following meanings: R 1 , R 2 alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which groups may be fluorinated, L T1 ~L T6 H, F or Cl, but L T1 ~L T6 At least one of them is F or Cl.

[0239] The compound of formula T is preferably selected from the group consisting of the following subformulae:

[0240] [ka]

[0241] [ka]

[0242] [ka] In the formula, R represents a linear alkyl or alkoxy group having 1 to 7 C atoms, and R * represents a linear alkenyl group having 2 to 7 carbon atoms, (O) represents an oxygen atom or a single bond, and m represents an integer of 1 to 6. * preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0243] R and R *preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.

[0244] Compounds of formula T1, T2 and T3, especially those of formula T1 and T2, are highly preferred.

[0245] Highly preferred are compounds of formulae T1 to T24, in which (O) represents an oxygen atom, m is 1, 2, 3, 4 or 5 and R is methyl, ethyl, propyl, butyl or pentyl or hexyl, the group preferably being linear.

[0246] Preferably the LC medium does not contain more than 15% of compounds of the formulae T or T1 to T24 or any other compounds bearing a terphenyl group.

[0247] Preferably the proportion of compounds of the formulae T or T1 to T24 or any other compounds carrying a terphenyl group in the LC medium is at least 5%, very preferably 5 to 15%, most preferably 5 to 10%.

[0248] Preferably the LC medium contains 1 to 5, very preferably 1 or 2, compounds of the formula T or T1 to T24.

[0249] f) LC medium or LC host mixtures comprising one or more compounds selected from the group consisting of the following formulae:

[0250] [ka] In the formula, alkyl is C 1~6 - represents alkyl, L x represents H or F and X represents F, Cl, OCF3, OCHF2 or OCH=CF2. Compounds of formula G1 in which X represents F are particularly preferred.

[0251] g) LC medium or LC host mixtures comprising one or more compounds selected from the group consisting of the following formulae:

[0252] [ka]

[0253] [ka]

[0254] [ka] In the formula, R 5 is R 1 has one of the meanings given above, and alkyl is C 1~6 -alkyl, d represents 0 or 1, and z and m each independently represent an integer of 1 to 6. 5 is particularly preferably C 1~6 -alkyl or -alkoxy or C 2~6 -alkenyl, and d is preferably 1. The LC media according to the invention preferably comprise one or more compounds of the above formulae in an amount of 5% by weight or more.

[0255] h) LC medium or LC host mixtures comprising one or more biphenyl compounds selected from the group consisting of the following formulae:

[0256] [ka] In the formula, alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 carbon atoms, and alkenyl and alkenyl * each independently represent a straight-chain alkenyl group having 2 to 6 carbon atoms. * preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0257] The proportion of biphenyls of the formulae B1 to B3 in the LC mixture is preferably at least 3% by weight, in particular 5% by weight or more.

[0258] Compounds of formula B2 are particularly preferred.

[0259] The compounds of formulae B1 to B3 are preferably selected from the group consisting of the following sub-formulae:

[0260] [ka] In the formula, alkyl * denotes an alkyl group having 1 to 6 C atoms. The medium according to the invention particularly preferably comprises one or more compounds of the formula B1a and / or B2c

[0261] i) An LC medium or LC host mixture comprising one or more compounds selected from the group consisting of the following formulae:

[0262] [ka] In the formula, R 1 and R 2 have the meanings given above and preferably each independently of one another denote straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms.

[0263] Preferred media comprise one or more compounds selected from formulae O1, O3 and O4.

[0264] k) LC media or LC host mixtures which comprise one or more compounds of the following formulae preferably in an amount of more than 3% by weight, in particular more than 5% by weight, very particularly preferably 5 to 30% by weight:

[0265] [ka] During the ceremony,

[0266] [ka] R 9 represents H, CH3, C2H5 or n-C3H7, (F) represents an optional fluorine substituent, q represents 1, 2 or 3, R 7 is R 1 It has one of the meanings given in

[0267] Particularly preferred compounds of formula FI are selected from the group consisting of the following subformulae:

[0268] [ka] In the formula, R 7 preferably represents a linear alkyl, and R 9 represents CH3, C2H5 or n-C3H7. Compounds of the formulae FI1, FI2 and FI3 are particularly preferred.

[0269] l) LC medium or LC host mixtures comprising one or more compounds selected from the group consisting of the following formulae:

[0270] [ka] In the formula, R 8 is R 1 where alkyl denotes a linear alkyl group having 1 to 6 carbon atoms.

[0271] m) LC media or LC host mixtures comprising one or more compounds containing a tetrahydronaphthyl or naphthyl unit, such as, for example, compounds selected from the group consisting of the following formulae:

[0272] [ka]

[0273] [ka] During the ceremony, R 10 and R 11 each independently represent alkyl having 1 to 12 C atoms (provided that in addition, one or two non-adjacent CH groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly linked to one another), preferably alkyl or alkoxy having 1 to 6 C atoms, and R 10 and R 11 preferably denotes linear alkyl or alkoxy having 1 to 6 C atoms or linear alkenyl having 2 to 6 C atoms, Z 1 and Z 2 represent, independently of one another, -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CH-CH2CH2-, -CH2CH2CH=CH-, -CHO-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CH2- or a single bond.

[0274] n) LC media or LC host mixtures which comprise one or more difluorodibenzochromans and / or chromans of the following formulae preferably in an amount of 3 to 20% by weight, in particular in an amount of 3 to 15% by weight:

[0275] [ka] During the ceremony, R 11 and R 12 are each independently of each other, R 11 has one of the meanings given above for Ring M is trans-1,4-cyclohexylene or 1,4-phenylene; Z m is -C2H4-, -CH2O-, -OCH2-, -CO-O- or -O-CO-, c is 0, 1 or 2.

[0276] Particularly preferred compounds of formula BC, CR and RC are selected from the group consisting of the following subformulae:

[0277] [ka]

[0278] [ka]

[0279] [ka] In the formula, alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms, (O) represents an oxygen atom or a single bond, c is 1 or 2, and alkenyl and alkenyl * each independently represent a straight-chain alkenyl group having 2 to 6 carbon atoms. * preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0280] Very particular preference is given to mixtures comprising one, two or three compounds of the formula BC-2.

[0281] o) LC media or LC host mixtures comprising one or more fluorinated phenanthrenes and / or dibenzofurans of the following formulae:

[0282] [ka] In the formula, R 11 and R 12are each independently of each other, R 11 wherein b represents 0 or 1, L represents F, and r represents 1, 2 or 3.

[0283] Particularly preferred compounds of formula PH and BF are selected from the group consisting of the following subformulae:

[0284] [ka] In the formula, R and R' each independently represent a linear alkyl or alkoxy group having 1 to 7 C atoms.

[0285] p) LC medium or LC host mixtures comprising one or more monocyclic compounds of the following formula:

[0286] [ka] During the ceremony, R 1 and R 2 each independently represent alkyl having 1 to 12 C atoms (provided that in addition, one or two non-adjacent CH groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly linked to one another), preferably alkyl or alkoxy having 1 to 6 C atoms, L 1 and L 2 each independently represent F, Cl, OCF3, CF3, CH3, CH2F or CHF2.

[0287] Preferably, L 1 and L 2 Both represent F or L 1 and L 2 One represents F and the other represents Cl.

[0288] The compound of formula Y is preferably selected from the group consisting of the following subformulae:

[0289] [ka] In the formula, Alkyl and Alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms, Alkoxy represents a linear alkoxy group having 1 to 6 C atoms, and Alkenyl and Alkenyl * each independently represent a straight-chain alkenyl group having 2 to 6 carbon atoms. * preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0290] Particularly preferred compounds of formula Y are selected from the group consisting of the following subformulae:

[0291] [ka] In the formula, Alkoxy preferably denotes straight-chain alkoxy having 3, 4 or 5 C atoms.

[0292] q) The LC medium does not contain compounds containing terminal vinyloxy groups (-O-CH=CH2).

[0293] r) The LC medium preferably comprises 1 to 5, preferably 1, 2 or 3, polymerizable compounds selected from formula I or any of its sub-formulas.

[0294] s) In the LC medium, the proportion of polymerizable compounds, in particular of formula I or any sub-formula thereof, is between 0.05 and 5%, preferably between 0.1 and 1%, in the mixture as a whole.

[0295] t) The LC medium comprises 1 to 8, preferably 1 to 5, compounds of the formulae CY1, CY2, PY1 and / or PY2. The proportion of these compounds in the overall mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably in each case 2 to 20%.

[0296] u) The LC medium comprises 1 to 8, preferably 1 to 5, compounds of the formulae CY9, CY10, PY9 and / or PY10. The proportion of these compounds in the overall mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably in each case 2 to 20%.

[0297] v) The LC medium comprises 1 to 10, preferably 1 to 8, compounds of the formula ZK, in particular compounds of the formulae ZK1, ZK2 and / or ZK6. The proportion of these compounds in the overall mixture is preferably 3 to 25%, particularly preferably 5 to 45%. The content of these individual compounds is preferably in each case 2 to 20%.

[0298] w) In the LC medium, the proportion of compounds of the formulae CY, PY and ZK in the mixture as a whole is more than 70%, preferably more than 80%.

[0299] x) the LC medium or LC host mixture is one or more compounds containing alkenyl groups, preferably R 1 and R 2 of the formulae CY, PY and LY, where one or both of R represents a linear alkenyl having 2 to 6 C atoms; 3 and R 4 or R 5 and R 6and compounds of the formulae ZK and DK, wherein one or both of the formulae ZK and DK are linear alkenyl having 2 to 6 carbon atoms; and B2 and B3, very preferably compounds selected from compounds of the formulae CY15, CY16, CY24, CY32, PY15, PY16, ZK3, ZK4, DK3, DK6, B2 and B3. The concentration of these compounds in the LC host mixture is preferably 2 to 70%, very preferably 3 to 55%.

[0300] y) The LC media contain one or more, preferably 1 to 5, compounds selected from the formulae PY1 to PY8, very preferably PY2. The proportion of these compounds in the overall mixture is preferably 1 to 30%, particularly preferably 2 to 20%. The proportion of each of these compounds is preferably in each case 1 to 20%.

[0301] The combination of the compounds of the preferred embodiments described above with the polymerized compounds described above results in LC media according to the invention with low threshold voltages, low rotational viscosities and very good low-temperature stability, and at the same time consistently high clearing points and high HR values, allowing particularly low pretilt angles to be rapidly established in PSA displays.In particular, compared with media from the prior art, in PSA displays the LC media show significantly reduced response times, and in particular reduced grey-shading response times.

[0302] The LC medium and LC host mixture according to the present invention can maintain a nematic phase down to -20°C, preferably down to -30°C, particularly preferably down to -40°C, and a clearing point above 70°C, preferably above 74°C, while simultaneously achieving a rotational viscosity γ1 of 120 mPa·s, thereby achieving excellent MLC displays with fast response times.

[0303] The LC media and LC host mixtures according to the invention preferably have a nematic phase range of at least 80 K, particularly preferably at least 100 K, and a rotational viscosity at 20° C. of 150 mPa·s or less, preferably 120 mPa·s or less.

[0304] In a VA-type display according to the invention, in the switched-off state, the molecules in the LC medium layer are aligned perpendicular to the electrode surface (homeotropic) or have a tilted homeotropic alignment. Application of a voltage to the electrodes causes a reorientation of the LC molecules with their long molecular axes parallel to the electrode surface.

[0305] For use in particular in displays of the PS-VA and PS-UB-FFS type, the LC media according to the invention preferably have a negative dielectric anisotropy Δε at 20° C. and 1 kHz of very preferably −0.5 to −10, most preferably −2.5 to −7.5.

[0306] For use in particular in displays of the PS-VA and PS-UB-FFS type, the birefringence Δn in the LC media according to the invention is preferably less than 0.16, very preferably between 0.06 and 0.14, most preferably between 0.07 and 0.12.

[0307] To increase the anchoring power, additional polymerizable compounds, so-called "reactive mesogens", may be added to the mixtures of the present invention. Preferred polymerizable compounds are listed in Table D.

[0308] The LC media according to the invention may also contain further additives known to those skilled in the art and described in the literature, such as, for example, polymerization initiators, inhibitors, stabilizers, surface-active substances or chiral dopants. These additives may be polymerizable or non-polymerizable. Polymerizable additives are therefore considered to belong to the polymerizable component or component A). Non-polymerizable additives are therefore considered to belong to the non-polymerizable component or component B).

[0309] The LC media according to the invention may also comprise UV stabilizers, antioxidants, free radical scavengers, nanoparticles, etc., such as, for example, one or more Tinuvin® from Ciba Chemical, in particular Tinuvin® 770. Suitable stabilizers are listed in Table C below.

[0310] The LC media according to the invention may also comprise one or more chiral dopants, for example, preferably in a concentration of 0.01 to 1%, very preferably 0.05 to 0.5%. Suitable chiral dopants are set out in Table B below. Preferred chiral dopants are for example selected from R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011 or R- or S-5011.

[0311] In another preferred embodiment, the LC medium contains a racemate of one or more chiral dopants, which are preferably selected from the chiral dopants mentioned in the previous paragraph.

[0312] It is also possible to add to the LC medium, for example, 0 to 15% by weight of pleochroic dyes, and furthermore nanoparticles, conductive salts to improve the conductivity, preferably ethyl dimethyl dodecyl ammonium 4-hexoxybenzoate, tetrabutyl ammonium tetraphenyl borate or complex salts of crown ethers (see, for example, Haller et al., Mol. Cryst. Liq. Cryst. 24, 249-258 (1973)), or substances for modifying the dielectric anisotropy, viscosity and / or alignment of the nematic phase. Substances of this type are described, for example, in DE-A-22 09 127, DE-A-22 40 864, DE-A-23 21 632, DE-A-23 38 281, DE-A-24 50 088, DE-A-26 37 430 and DE-A-28 53 728.

[0313] The individual components of the preferred embodiments a) to y) of the LC media according to the invention are either known or their preparation is based on standard methods described in the literature and can therefore be easily derived by those skilled in the art from the prior art. Compounds of formula CY are described, for example, in EP-A-0 364 538. Compounds of formula ZK are described, for example, in DE-A-26 36 684 and DE-A-33 21 373.

[0314] It goes without saying for those skilled in the art that the LC media according to the invention may also include compounds in which, for example, H, N, O, Cl, F are replaced by the corresponding isotopes, such as deuterium.

[0315] The LC media that can be used according to the present invention can be prepared in a conventional manner, for example, by mixing one or more compounds of formulae B and Q with one or more compounds of the above-mentioned preferred embodiments and / or with additives such as further liquid crystal compounds and / or polymerizable compounds or RM. The desired amount of the component, which is generally used in small amounts, is dissolved in the component that constitutes the main component, advantageously at elevated temperatures. It is also possible to mix solutions of the components in organic solvents, such as acetone, chloroform or methanol, and, after thorough mixing, remove the solvent again, for example by distillation.

[0316] It goes without saying that by appropriately selecting the components of the LC mixtures according to the invention, it is also possible to achieve higher clearing points (e.g., above 100°C) at higher threshold voltages or lower clearing points at lower threshold voltages, while retaining other advantageous properties. Similarly, mixtures with higher Δε and thus lower thresholds can be obtained. MLC displays according to the invention preferably operate in the first Gooch and Tarry transmission minimum [C.H. Gooch and H.A. Tarry, Electron. Lett. 10, pp. 2-4, 1974; C.H. Gooch and H.A. Tarry, Appl. Phys. 8, pp. 1575-1584, 1975], and in addition to particularly favorable electro-optical properties, such as high characteristic line steepness and low angular dependence of contrast (German Patent No. 30 22 818), lower dielectric anisotropy is also sufficient at the same threshold voltage as in similar displays in the second minimum. This makes it possible to achieve significantly higher resistivity values ​​at the first minimum using the mixtures according to the invention than with mixtures containing cyano compounds. By appropriately selecting the individual components and their weight ratios, a person skilled in the art can use simple routine methods to set the required birefringence for a pre-specified layer thickness in an MLC display.

[0317] The construction of the LC display according to the invention from polarizers, electrode base plates and surface-treated electrodes corresponds to the conventional design of this type of display, the term conventional design being used in the broad sense herein to encompass all derivatives and modifications of LC displays, in particular matrix display elements based on poly-Si TFT or MIM.

[0318] The following examples are intended to illustrate, without limiting, the invention. Above and below, percentage data represent percent by weight; all temperatures are expressed in degrees Celsius.

[0319] Throughout this patent application and in the examples, the structures of liquid crystal compounds are indicated by acronyms. Unless otherwise indicated, conversion to chemical formulas is made according to Tables I to III. All groups C n H 2n+1 , C m H 2m+1 , C n H 2n , C m H 2m and C k H 2k are in each case straight-chain alkyl or alkenyl groups each having n, m or k C atoms, where n and m each independently represent 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, preferably 1, 2, 3, 4, 5 or 6, and k is 1, 2, 3, 4, 5 or 6. In Table I, the ring elements of each compound are coded, Table II lists the linking elements, and Table III gives the meaning of the symbols for the left and right side chains of the compounds.

[0320] [Table 1]

[0321] [Table 2]

[0322] [Table 3]

[0323] [Table 4] Preferred mixture components are shown in Table A.

[0324] [Table 5]

[0325] [Table 6]

[0326]

Table 7

[0327]

Table 8

[0328]

Table 9

[0329]

Table 10

[0330]

Table 11

[0331]

Table 12

[0332]

Table 13

[0333]

Table 14

[0334]

Table 15

[0335] Table 16

[0336] [Table 17]

[0337] [Table 18]

[0338] [Table 19]

[0339] [Table 20]

[0340] [Table 21] Liquid crystal mixtures comprising at least one, two, three or more compounds from Table A are particularly preferred.

[0341] Table B lists dopants which may generally be added to the mixtures according to the invention. The mixtures preferably contain 0 to 10% by weight, in particular 0.001 to 5% by weight, particularly preferably 0.001 to 3% by weight, of dopants.

[0342] [Table 22]

[0343] [Table 23]

[0344] [Table 24]

[0345] [Table 25]

[0346] Table 26

[0347] Table 27

[0348] Table 28

[0349] Table 29

[0350] Table 30

[0351] Table 31

[0352] Table 32

[0353]

Table 33

[0354] Table 34

[0355] Table 35

[0356] Table 36

[0357] Table 37

[0358] Table 38

[0359] Table 39

[0360] Table 40

[0361] Table 41

[0362] Table 42

[0363] Table 43

[0364] Table 44

[0365] Table 45 In a preferred embodiment, the mixture according to the invention comprises one or more polymerizable compounds, preferably selected from the polymerizable compounds of formulae RM-1 to RM-131, of which the compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-43, RM-47, RM-49, RM-51, RM-59, RM-69, RM-71, RM-83, RM-97, RM-98, RM-104, RM-112, RM-115 and RM-116 are particularly preferred. [Example]

[0366] The following examples illustrate the invention without limiting it. However, they give the skilled person an idea of ​​the preferred mixtures, together with the compounds to be preferably used and their respective concentrations and their combinations with one another. In addition, the examples illustrate which properties and property combinations are possible.

[0367] In addition, the following abbreviations and symbols are used: V0 is the capacitance threshold voltage [V] at 20°C, n e is the extraordinary refractive index at 20°C and 589 nm, n0 is the ordinary refractive index at 20°C and 589 nm, Δn is the optical anisotropy at 20°C and 589 nm; ε ⊥ is the dielectric constant perpendicular to the director at 20°C and 1 kHz, ε ∥ is the dielectric constant parallel to the director at 20°C and 1 kHz, Δε is the dielectric anisotropy at 20 °C and 1 kHz, cl.p., T(N,I) is the clearing point [°C], γ1 is the rotational viscosity at 20°C [mPa·s], K1 is the elastic constant for "splay" deformation at 20°C [pN], K2 is the elastic constant for "twist" deformation at 20°C [pN], K3 is the elastic constant for "bend" deformation [pN] at 20°C.

[0368] Unless otherwise specified, all concentrations in this application are given in weight percent and refer to the corresponding total mixture, including all solid or liquid crystal components, excluding solvent.

[0369] Unless otherwise specified, all temperature values ​​given in this application, such as the melting point T(C,N), the smectic (S) to nematic (N) phase transition T(S,N), and the clearing point T(N,I), are given in degrees Celsius (°C). mp denotes the melting point, cl.p. denotes the clearing point. Furthermore, C is the crystalline state, N is the nematic phase, S is the smectic phase, and I is the isotropic phase. The data between these symbols represent the transition temperatures.

[0370] All physical properties are or have been determined in accordance with "Merck Liquid Crystals, Physical Properties of Liquid Crystals", November 1997, Merck KGaA, Germany, and unless otherwise stated in each case, a temperature of 20°C applies, Δn is determined at 589 nm and Δε is determined at 1 kHz.

[0371] For the present invention, the term "threshold voltage" refers to the capacitive threshold (V), also known as the Freederickss threshold, unless otherwise specified. Also, in the examples, and as is generally usual, the threshold voltage is referred to as the 10% relative contrast (V 10 ) may also be given as the optical threshold.

[0372] Unless otherwise specified, the process of polymerizing the polymerizable compounds in the PSA displays, as described above and below, is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, preferably a nematic phase, and most preferably at room temperature (also abbreviated as RT).

[0373] Unless otherwise specified, the methods for preparing the test cells and measuring their electro-optical and other properties are as or similar to those described hereinafter.

[0374] The display used for measuring the capacitance threshold voltage consists of two flat and parallel outer glass plates separated by a distance of 25 μm. Each outer plate has an electrode layer on the inner side and an unrubbed polyimide alignment layer on the uppermost part, resulting in a homeotropic edge alignment of liquid crystal molecules.

[0375] The display or test cell used for measuring the tilt angle consists of two flat and parallel outer glass plates separated by a distance of 4 μm. Each outer plate has an electrode layer on the inner side and a polyimide alignment layer on the uppermost part. However, the two polyimide layers are rubbed in antiparallel to each other, resulting in a homeotropic edge alignment of liquid crystal molecules.

[0376] The polymerizable compound polymerizes in the display or test cell by irradiation with UVA light of a specified intensity for a predetermined time while simultaneously applying a voltage (usually 10V - 30V AC, 1kHz) to the display. In the example, unless otherwise indicated, for polymerization, a metal halide lamp with an intensity of 50 mW / cm 2 is used. The intensity is measured using a standard meter (a high-range Hoenle AUV meter equipped with a UVA sensor).

[0377] The tilt angle is determined by a crystal rotation experiment (Autronic-Melchers TBA-105). Here, a low value (i.e., a large deviation from an angle of 90°) corresponds to a large tilt.

[0378] The VHR value is measured as follows: Add 0.3% of the polymerizable monomer compound to the LC host mixture and introduce the resulting mixture into a VA-VHR test cell containing an unrubbed VA-polyimide alignment layer. Unless otherwise stated, the LC layer thickness d is approximately 6 μm. Determine the VHR values before and after UV exposure at 1V, 60Hz, 64 μs pulses (measurement device: Autronic-Melchers VHRM-105).

[0379] <LC host mixture> <Comparative Example 1A> The nematic LC host mixture C0 is formulated as follows.

[0380] [Table 46] The mixture does not contain a compound of formula B or Q.

[0381] <Comparative example 1B> The nematic LC host mixture C1 is formulated as follows.

[0382] [Table 47] The mixture contains the compound of formula B (B(S)-2O-O5) but does not contain the compound of formula Q.

[0383] <Example 1> The nematic LC host mixture N1 is formulated as follows.

[0384] [Table 48] The mixture contains a compound of formula B (B(S)-2O-O5) and a compound of formula Q (PPGU-3-F).

[0385] <Comparative Example C2> Nematic LC host mixture C2 is prepared as follows.

[0386] [Table 49] The mixture contains the compound of formula B (B(S)-2O-O5) but does not contain the compound of formula Q.

[0387] <Example 2> The nematic LC host mixture N2 is formulated as follows.

[0388] [Table 50] The mixture contains a compound of formula B (B(S)-2O-O5) and a compound of formula Q (PPGU-3-F).

[0389] <Comparative Example C3> Nematic LC host mixture C3 is prepared as follows.

[0390] [Table 51] The mixture contains two compounds of formula B (B(S)-2O-O4, B(S)-2O-O5), but no compound of formula Q.

[0391] <Example 3> Nematic LC host mixture N3 is formulated as follows.

[0392] [Table 52] The mixture contains two compounds of formula B (B(S)-2O-O4, B(S)-2O-O5) and a compound of formula Q (PPGU-3-F).

[0393] <Comparative example C4> Nematic LC host mixture C4 is prepared as follows.

[0394] [Table 53] The mixture contains two compounds of formula B (B(S)-2O-O4, B(S)-2O-O5), but no compound of formula Q.

[0395] <Example 4> The nematic LC host mixture N4 is formulated as follows.

[0396] [Table 54] The mixture contains two compounds of formula B (B(S)-2O-O4, B(S)-2O-O5) and a compound of formula Q (PPGU-3-F).

[0397] <Usage example> Table 1 shows the rotational viscosity of LC host mixtures C0-C4 and N1-N4 as a function of the concentration of the compound of formula B.

[0398] [Table 55] It can be seen from Table 1 that as the concentration of compound B(S)-nO-Om of formula B increases, the rotational viscosity of the LC host mixture decreases, indicating that the addition of compound B has the beneficial effect of reducing the rotational viscosity, resulting in a shorter response time.

[0399] <Polymerizable mixture> Polymerizable mixtures are prepared by adding reactive mesogen M1 at a concentration of 0.35 wt % to each of the nematic LC host mixtures C0-C4 and N1-N4.

[0400] [ka] The composition of the polymerizable mixture is shown in Table 2 below.

[0401] [Table 56] The VHR value of the polymerizable mixture is measured at 60° C. in a VA-VHR test cell before and after UV exposure for 80 minutes at room temperature using a fluorescent UV lamp type C (305 nm to 355 nm).

[0402] The VHR values ​​of the polymerizable mixtures are shown in Table 3.

[0403] [Table 57] From Table 3, it can be seen that the initial VHR values ​​of all polymerizable mixtures CP0 to CP4 and P1 to P4 are at almost the same level.

[0404] However, after polymerization, mixtures CP1 to CP4 and P1 to P4 show an increasing decrease in VHR with increasing compound of formula B compared to mixture CP0 without compound of formula B.

[0405] On the other hand, in the mixtures P1 to P4 according to the present invention which additionally contain a compound of formula Q, the increase in the VHR drop after polymerization is reduced as the amount of the compound of formula B is increased compared to the mixtures CP1 to CP4 which do not contain a compound of formula Q.

[0406] This effect is particularly important in mixtures P2 to P4, which have higher VHR after polymerization and higher concentrations of compounds of formula B than comparative mixtures C2 to C4.

[0407] Thus, the addition of a compound of formula Q to an LC medium can reduce the decrease in VHR, which is observed when increasing the amount of compound B added to the LC medium. The effect is particularly important for mixtures with higher amounts of compound of formula B. Adding higher amounts of compound of formula B is desirable since it leads to lower viscosities as shown above, and the use of mixtures P1 to P4 according to the invention allows combining the advantages of both low viscosity and high reliability.

Claims

1. A liquid crystal (LC) medium comprising one or more polymerizable compounds, one or more compounds of formula B1 in the range of 4 to 15% by weight, based on the total LC medium, and one or more compounds selected from compounds of formula Q1 or Q2 in the range of 0.1 to 2% by weight, based on the total LC medium. 【Chemical 1】 (In the formula, alkyl represents a straight-chain alkyl group having 1 to 6 C atoms, and (O) represents an oxygen atom or a single bond. 【Chemistry 2】 (In the formula, R Ｑ represents alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms.

2. a polymerizable component A) containing one or more polymerizable compounds, and Liquid crystal component B) containing one or more mesogens or liquid crystal compounds LC medium comprising LC medium according to claim 1, characterized in that component B) comprises one or more compounds selected from one or more compounds of the formula B1 and compounds of the formula Q1 or Q2 as defined in claim 1.

3. LC medium according to claim 1 or 2, characterized in that it comprises one or more compounds of the formula B1 selected from compounds of the formula B(S)-nO-Om or B(S)-n-Om 【Chemistry 3】 (In the formula, m and n each independently represent an integer of 1 to 6.

4. LC medium according to claim 3, characterized in that it comprises one or more compounds of the formula B1 selected from compounds of the formula B(S)-nO-Om. 【Chemistry 4】 (In the formula, m and n each independently represent an integer of 1 to 6.

5. LC medium according to any one of claims 1 to 4, characterized in that the polymerisable compound is selected from the formula I. 【Chemistry 5】 wherein the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another: R ａ and R ｂ P, P-Sp-, H, F, Cl, Br, I, -CN, -NO ２ , -NCO, -NCS, -OCN, -SCN, SF ５ or linear or branched alkyl having 1 to 25 C atoms, provided that in addition there are one or more non-adjacent CH ２ The groups may each independently be formed by a -C(R ０ ) = C(R ００ )-, -C≡C-, -N(R ００ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, provided that in addition one or more H atoms may be replaced by F, Cl, Br, I, CN, P or P-Sp-, provided that B １ and / or B ２ contains saturated C atoms, and R ａ and / or R ｂ may represent a group spiro-linked to this saturated C atom, where the group R ａ and R ｂ at least one of which represents or contains a group P or P-Sp-, P polymerizable group, Sp a spacer group or a single bond; B １ and B ２ an aromatic, heteroaromatic, alicyclic or heterocyclic group having 4 to 25 ring atoms, which may also contain fused rings, which group is unsubstituted or mono- or polysubstituted by L; Z ｂ -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH ２ -, -CH ２ O-, -SCH ２ -, -CH ２ S-, -CF ２ O-, -OCF ２ -, -CF ２ S-, -SCF ２ -, -(CH ２ ) ｎ１ -, -CF ２ CH ２ -, -CH ２ CF ２ -, -(CF ２ ) ｎ１ -, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, CR ０ R ００ or a single bond, R ０ and R ００ H or alkyl having 1 to 12 C atoms, m 0, 1, 2, 3 or 4, n1 1, 2, 3 or 4, L P, P-Sp-, OH, CH ２ OH, F, Cl, Br, I, -CN, -NO ２ , -NCO, -NCS, -OCN, -SCN, -C(=O)N(R ｘ ) ２ , -C(=O)Y １ , -C(=O)R ｘ , -N(R ｘ ) ２ , optionally substituted silyl, optionally substituted aryl having 6 to 20 C atoms or linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, provided that in addition one or more H atoms may be replaced by F, Cl, P or P-Sp-, Y １ halogen, R ｘ P, P-Sp-, H, halogen, linear, branched or cyclic alkyl having 1 to 25 carbon atoms (but in addition one or more non-adjacent CH ２ The group may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not directly linked to one another, with the proviso that in addition one or more H atoms may be replaced by F, Cl, P or P-Sp-), an optionally substituted aryl or aryloxy group having 6 to 40 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 C atoms.

6. LC medium according to any one of claims 1 to 5, characterized in that the polymerisable compound is selected from the following formulae: 【Chemistry 6】 【Chemistry 7】 【Chemistry 8】 【Chemistry 9】 wherein the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another: P １ , P ２ , P ３ vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane or epoxy groups, Sp １ , Sp ２ , Sp ３ a single bond or a spacer group, provided that in addition, the group P １ -Sp １ -, P ２ -Sp ２ - and P ３ -Sp ３ At least one of - is R ａａ one or more groups P １ -Sp １ -, P ２ -Sp ２ - and P ３ -Sp ３ - is R ａａ It can be expressed as R ａａ H, F, Cl, CN, or linear or branched alkyl having 1 to 25 C atoms (but in addition one or more non-adjacent CH ２ The groups may each be independently C(R ０ ) = C(R ００ )-, -C≡C-, -N(R ０ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, provided that in addition one or more H atoms may be replaced by F, Cl, CN or P １ -Sp １ - may be replaced by .) R ０ , R ００ H or alkyl having 1 to 12 C atoms, X １ , X ２ , X ３ —CO—O—, —O—CO— or a single bond, Z １ -O-、-C-、-C(R ｙ R ｚ )-or-CF ２ CF ２ -、 Z ２ , Z ３ -CO-O-, -O-CO-, -CH ２ O-, -OCH ２ -, -CF ２ O-, -OCF ２ - or - (CH ２ ) ｎ -, where n is 2, 3 or 4; L F, Cl, CN or linear or branched, optionally monofluorinated or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, L', L" H, F or Cl, r 0, 1, 2, 3 or 4, s 0, 1, 2 or 3, t 0, 1 or 2, x 0 or 1.)

7. 7. LC medium according to claim 1, comprising one or more compounds selected from the formulae AN and AY. 【Chemistry 10】 wherein the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another: 【Chemistry 11】 【Chemistry 12】 【Chemistry 13】 【Chemistry 14】 R Ａ１ Alkenyl having 2 to 9 carbon atoms, when at least one of the rings X, Y and Z represents cyclohexenyl, and R Ａ２ One of the meanings of R Ａ２ Alkyl having 1 to 12 C atoms, but in addition having 1 or 2 non-adjacent CH ２ groups may be replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that the O atoms are not directly linked to one another; Z ｘ -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, L １～４ H, F, Cl, OCF ３ , C.F. ３ , C.H. ３ , C.H. ２ F or CHF ２ H. x 1 or 2, z 0 or 1.)

8. 8. LC medium according to any one of claims 1 to 7, characterized in that it comprises one or more compounds selected from the formulae CY and PY, with the exception of compounds of the formula AY as defined in claim 7. 【Chemistry 15】 wherein the individual groups have the following meanings: a represents 1 or 2; b represents 0 or 1; 【Chemistry 16】 【Chemistry 17】 R １ and R ２ each independently represent alkyl having 1 to 12 C atoms, provided that in addition there are 1 or 2 non-adjacent CH ２ groups may be replaced by —O—, —CH═CH—, —CO—, —O—CO— or —CO—O— in such a way that the O atoms are not directly linked to each other; Z ｘ is -CH=CH-, -CH ２ O-, -OCH ２ -, -CF ２ O-, -OCF ２ -, -O-, -CH ２ -, -CH ２ CH ２ represents - or a single bond, L １～４ are each independently F, Cl, OCF ３ , C.F. ３ , C.H. ３ , C.H. ２ F, CHF ２ Represents.)

9. 9. LC medium according to any one of claims 1 to 8, characterized in that it comprises one or more compounds selected from the formulae ZK and DK, with the exception of compounds of the formula AN as defined in claim 7. 【Chemistry 18】 wherein the individual groups at each occurrence have the following meanings, which may be the same or different: 【Chemistry 19】 【Chemistry 20】 【Chemical 21】 【Chemical 22】 R ３ and R ４ each independently represent alkyl having 1 to 12 C atoms, provided that in addition there are 1 or 2 non-adjacent CH ２ groups may be replaced by —O—, —CH═CH—, —CO—, —O—CO— or —CO—O— in such a way that the O atoms are not directly linked to each other; Z ｙ is -CH ２ CH ２ -, -CH=CH-, -CF ２ O-, -OCF ２ -, -CH ２ O-, -OCH ２ -, -COO-, -OCO-, -C ２ F ４ represents -, -CF=CF- or a single bond; R ５ and R ６ are each independently an alkyl having 1 to 12 C atoms (but in addition may have 1 or 2 non-adjacent CH ２ The group may be replaced by —O—, —CH═CH—, —CO—, —O—CO— or —CO—O— in such a way that the O atoms are not directly linked to each other, e represents 1 or 2.

10. LC medium according to any one of claims 1 to 9, characterized in that the polymerizable compound is polymerized.

11. LC display comprising an LC medium as defined in any one of claims 1 to 10.

12. 12. The LC display of claim 11 which is a PSA type display.

13. 13. The LC display of claim 12 which is a PS-VA, PS-IPS or PS-UB-FFS display.

14. It comprises two substrates, at least one of which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and a layer of an LC medium as defined in any one of claims 1 to 9, arranged between the substrates, with the proviso that the polymerizable compound is polymerized between the substrates of the display.

14. An LC display according to claim 12 or 13.

15. 15. A method for manufacturing an LC display according to claim 14, comprising the steps of: providing an LC medium as defined in any one of claims 1 to 9 between the substrates of a display, and and polymerizing the polymerizable compound.

16. A process for preparing an LC medium according to any one of claims 1 to 9, comprising the steps of 1. A process comprising the step of mixing one or more compounds selected from compounds of formula B1 as defined in claim 1 or compounds of formula B(S)-nO-Om or B(S)-n-Om as defined in claim 3 with one or more compounds of formula Q1 or Q2 as defined in claim 1, one or more polymerizable compounds as defined in claims 1, 5 or 6, and optionally further LC compounds and / or additives.

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