KR102587314B1 - Liquid crystal medium - Google Patents

Abstract

The present invention relates to a liquid crystal (LC) medium comprising polymerizable compounds, a process for its preparation, a method for optical, electro-optical and electrical purposes, in particular LC displays, especially of the polymer sustained alignment (PSA) type. It relates to its use for LC displays, and LC displays comprising the same, especially PSA displays.

Description

Liquid crystal medium {LIQUID CRYSTAL MEDIUM}

The present invention relates to a liquid crystal (LC) medium comprising polymerizable compounds, a process for its preparation, a method for optical, electro-optical and electrical purposes, in particular LC displays, especially of the polymer sustained alignment (PSA) type. It relates to its use for LC displays, and LC displays comprising the same, especially PSA displays.

A liquid crystal display mode that has widespread interest and commercial use is the so-called PS (“polymer sustained”) or PSA (“polymer sustained orientation”) mode, which is sometimes also used by the term “polymer stabilized”. . In a PSA display, the LC mixture (hereinafter also referred to as the “host mixture”) and a small amount, typically less than 1% by weight, such as 0.2 to 0.4% by weight, of one or more polymerisable compounds, preferably polymerisable monomers. An LC medium containing the compound is used. After charging the LC medium into the display, the polymerizable compound is polymerized or cross-linked in situ, usually by UV photopolymerization, optionally while a voltage is applied to the electrodes of the display. The polymerization is carried out at a temperature at which the LC medium exhibits a liquid crystalline phase, usually room temperature. The addition of polymerizable mesogens or liquid crystalline compounds, also known as reactive mesogens or “RM”, to the LC host mixture has proven particularly suitable.

Meanwhile, the PS(A) mode is used in various common LC display types. Thus, 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 announced The polymerization of the RM may preferably occur with an applied voltage in the case of PS-VA and PS-OCB displays and may occur with or without, preferably without, an applied voltage in the case of PS-IPS displays. As a result, a pretilt angle of LC molecules is generated within the display cell. For PS-OCB displays, for example, the bend structure is stabilized so that the offset voltage is unnecessary or can be reduced. For PS-VA displays, the pretilt angle is It has a positive impact on response time.For PS-VA displays, standard MVA (“multidomain VA”) or PVA (“patterned VA”) pixel and electrode layouts can be used. It is also possible to use just a single structured electrode without protrusions, which significantly simplifies production and improves contrast and transparency.

Additionally, the so-called posi-VA mode (“positive VA”) has proven to be particularly suitable. As in conventional VA and PS-VA displays, the initial orientation of the LC molecules in a posi-VA display is homeotropic (i.e., substantially perpendicular to the substrate in the initial state when no voltage is applied). However, in contrast to conventional VA and PS-VA displays, in posi-VA displays an LC medium with positive dielectric anisotropy is used. As in the IPS and PS-IPS displays, the two electrodes in the Posey-VA display are aligned on only one of the two substrates, preferably intermeshed and comb-shaped (Interdigital). (interdigital)) represents the structure. When a voltage is applied to the interdigital electrode to generate an electric field substantially parallel to the layer of LC medium, the LC molecules switch to an orientation that is substantially parallel to the substrate. In Posey-VA displays, it has also proven advantageous to stabilize the polymer by adding RM to the LC medium and then polymerizing it within the display. This can achieve significant switching time reductions.

PS-VA displays are described for example in EP1170626A2, US6861107, US7169449, US2004/0191428A1, US2006/0066793A1 and US2006/0103804A1. PS-OCB displays are described, for example, in T.-J-Chen et al., Jpn. J. Appl. Phys. 45, 2006, 2702-2704] and [S. H. Kim, L.-C-Chien, Jpn. J. Appl. Phys. 43, 2004, 7643-7647]. PS-IPS displays are described, for example, in US 6177972 and [Appl. Phys. Lett. 1999, 75(21), 3264]. PS-TN displays are described, for example, in Optics Express 2004, 12(7), 1221.

PSA displays can be operated as active-matrix or passive-matrix displays. For active-matrix displays, individual pixels are often addressed by integrated non-linear active elements, such as transistors (e.g. thin-film transistors or “TFTs”), whereas for passive-matrix displays, each The pixels of are often addressed by complex methods known from the prior art.

PSA displays may also include an orientation layer on one or both of the substrates forming the display cell. The orientation layer is often applied over the electrodes (if such electrodes exist), contacting the LC medium and inducing an initial orientation of the LC molecules. The orientation layer may comprise or consist of polyimide, which may be rubbed or prepared, for example, by photoalignment methods.

In particular, for monitors and especially TV products, optimization of the contrast and luminance (and therefore transmittance) of LC displays as well as response time is still required. The PSA method can offer significant advantages here. Particularly for the PS-VA, PS-IPS, PS-FFS and PS-Forge-VA displays, a reduction in response time relative to the measurable preslope within the test cell can be achieved without significant adverse effects on other variables.

The prior art suggests biphenyl diacrylate or dimethacrylate, optionally fluorinated, as RM for use in PSA displays.

However, not all combinations of LC host mixtures and RM are suitable for use in PSA displays, for example because only unsuitable tilt angles occur or no tilt angles occur, or because, for example, the voltage retention ratio (VHR) is not suitable for TFT display products. The problem arises that this is not the case. It has also been found that when used in PSA displays, the LC mixtures and RMs known from the prior art still have some disadvantages. Therefore, not all known RMs that are soluble in LC host mixtures are suitable for use in PSA displays. Additionally, it is usually difficult to find suitable selection criteria for RM other than direct measurement of pretilt in PSA displays. If UV photopolymerization is required without the addition of photoinitiator to benefit a particular product, the choice of suitable RM becomes more narrow.

Additionally, the selected combination of LC host mixture/RM should have low rotational viscosity and good electrical properties, especially high VHR. In PSA displays, high VHR after irradiation with UV light is particularly important because UV exposure not only occurs as a normal exposure during operation of the final display, but is also an integral part of the display production process.

In particular, it would be desirable to have improved materials available for PSA displays that provide very small pretilt angles. Preferred materials are those that, compared to prior art materials, are capable of producing a lower pretilt angle after the same exposure time and/or are capable of producing one or more identical pretilt angles after a shorter exposure time. This may allow to reduce display production time (“tact time”) and production costs.

A further problem in the manufacture of PSA displays is the presence and removal of residual amounts of unpolymerized RM after the polymerization step essential for the generation of pretilt angles in the display. Unreacted RM may have a negative impact on the display, for example by polymerizing in an uncontrolled manner during display operation.

Accordingly, PSA displays known from the prior art usually suffer from the so-called "image sticking" or "image burn" (i.e. the loss of individual pixels even after the electric field within the pixel has been switched off or even after other pixels have been addressed). images generated on an LC display by transient addressing) often exhibit undesirable effects.

Afterimages can occur, for example, when LC host mixtures with low VHR are used. sunlight or display backlight UV components can cause undesirable decomposition reactions of LC molecules and initiate the production of ionic or free-radical impurities. They can accumulate especially in the electrode or orientation layer, where they reduce the effective applied voltage. This effect can also be observed in conventional LC displays without polymer components.

Additional afterimage effects caused by the presence of unpolymerized RM are often observed in PSA displays. Uncontrolled polymerization of the remaining RM is initiated by UV light from sunlight or backlight. In a switched display area, this changes the tilt angle after several addressing cycles. As a result, changes in transmittance may occur in the switched region, but remain constant in the unswitched region.

Therefore, during the production of PSA displays, it is desirable for the polymerization of the RMs to proceed as completely as possible, so that the presence of unpolymerized RMs in the display can be excluded or reduced to a minimum. Therefore, there is a need for RM and LC host mixtures that enable or assist rapid and complete polymerization of RM. Additionally, a controlled response of the amount of residual RM is desirable. This can be achieved by providing improved RMs that polymerize faster and more effectively than prior art RMs.

A further problem observed in the operation of PSA displays is the stability of the pretilt angle. Accordingly, it has been observed that the pretilt angle generated during display manufacturing by polymerizing RM may not remain constant and may worsen after voltage stress is applied to the display during display operation. This can negatively impact display performance, for example by increasing black state transmittance and thus reducing contrast.

Another problem to be solved is that prior art RMs often have high melting points and show only limited solubility in many commonly used LC mixtures. As a result, RM tends to spontaneously crystallize outside the LC mixture. Additionally, the risk of spontaneous polymerization prevents the ability to warm the LC host mixture to better dissolve RM, requiring high solubility even at room temperature. Additionally, for example, when filling an LC display with an LC medium, there is a risk of phase separation (chromatographic effect), which can greatly impair the homogeneity of the display. This can be further exacerbated by the fact that the LC medium is often filled into the display at low temperatures to reduce the risk of spontaneous polymerization (see above), which in turn has a negative impact on solubility.

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, particularly by using the one drop filling (ODF) method, causes the LC media to be injected into the display. When charging, spots often appear on the display. This phenomenon is also known as “ODF mura”. Therefore, it is desirable to provide an LC medium that leads to reduced ODF staining.

Another problem observed in the prior art is that the LC media used in PSA displays, including but not limited to PSA type displays, often exhibit high viscosity and, consequently, high switching times. In order to reduce the viscosity and response time of the LC medium, the addition of LC mixtures with alkenyl groups has been proposed in the prior art. However, LC media containing alkenyl groups are often observed to show a decrease in reliability and stability and a decrease in VHR, especially after exposure to UV irradiation. Particularly when used in PSA displays, photo-polymerization of RMs in PSA displays is usually carried out by exposure to UV irradiation, which is a serious disadvantage, since this may cause VHR drop in the LC medium.

In the prior art, the LC media used in PSA displays were proposed so that the LC host mixture contained one or more terphenyl compounds to enhance the polymerization of RM. However, addition of terphenyl compounds increases the viscosity of the LC host mixture and thus results in slower response times. Moreover, the addition of terphenyl compounds can lead to reduced reliability and a drop in VHR after UV stress in the LC medium.

Therefore, another challenge is to provide LC mixtures and LC media for PSA displays that can enable rapid and complete polymerization of RM while exhibiting reduced viscosity and high VHR.

Accordingly, there still exists a significant need for PSA displays and LC media and polymerizable compounds for use in such displays that do not exhibit or only slightly exhibit the disadvantages described above and have improved properties.

In particular, high resistivity and at the same time wide operating-temperature range, short response time even at low temperatures, low threshold voltage, low pretilt angle, variable gray shades, high contrast and wide viewing angle, high reliability and high VHR value after UV exposure, and RM of There is still a significant need for PSA displays and LC mixtures and RMs for use in such displays that have low melting points and high solubility in the LC host mixture. For PSA displays for mobile applications, it is particularly desirable to have available LC media that exhibit low threshold voltage and high birefringence.

The present invention is based on the object of providing new and suitable materials for use in PSA displays, in particular RMs, LC host mixtures and LC media comprising them, which do not have the disadvantages described above or only to a reduced extent.

In particular, the present invention enables very high resistivity values, high VHR values, high reliability, low threshold voltage, short response time, high birefringence, shows excellent UV absorption, especially at longer wavelengths, and has a fast and fast rate of embedded RM. Enables complete polymerization, generates low pretilt angles as quickly as possible, enables high stability of pretilt even after longer times and/or UV exposure, reduces or prevents the occurrence of afterimages within the display, and eliminates ODF staining within the display. It is based on the objective of providing an LC medium for use in PSA displays that reduces or prevents the occurrence of .

Another object of the present invention is to solve the problem of providing LC mixtures and LC media for PSA displays, which allow rapid and complete polymerization of RM while showing reduced viscosity and high VHR.

The above object is achieved according to the invention by means of the materials and methods described and claimed herein.

Surprisingly, at least some of the above-mentioned problems involve LC host mixtures containing a polymerizable component and compounds of formulas A, B and T, and further described and claimed hereinafter, according to formula S. It was confirmed that the problem could be solved by using an LC medium additionally containing at least one amine-based light stabilizer (HALS) or its derivative.

Therefore, it has been confirmed that when using the LC media described and claimed hereinafter in PSA displays, it is possible to maintain high UV absorption, and strong tilt angle generation required for fast and complete polymerization, while maintaining high VHR.

It was also confirmed that improvement in the VHR can be achieved by adding a stabilizing compound of formula S to the mixture.

The use of the LC medium according to the invention facilitates a fast and complete UV-photopolymerization reaction, especially at low UV energies and/or at longer UV wavelengths of 300 to 380 nm and especially >340 nm, which is a significant advantage in the display manufacturing process. am. Moreover, the use of the LC medium according to the present invention enables the rapid generation of large and stable pretilt angles, reduces afterimages and ODF stains in the display, leads to high VHR values after UV photopolymerization, fast response time, and low threshold voltage. and achieve high birefringence.

US 2012/0268706 A1 describes stabilizers of formula S and LC media comprising them, but does not describe or suggest the polymerizable LC media subsequently described and claimed herein.

The present invention,

- polymerisable component A) comprising, preferably consisting of at least one polymerisable compound

- also referred to as “LC host mixture”, comprising, preferably consisting of, one or more mesogenic or liquid crystal compounds comprising at least one compound of formula A, at least one compound of formula B and at least one compound of formula T: Liquid crystal component B):

[In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:

R ¹ , R ² and R ^Q represent alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 carbon atoms or alkenyl or alkenyloxy having 2 to 9 carbon atoms, all of which are optional fluorinated,

X ^Q shows a halogenated alkyl or alkoxy having F, CL, 1 to 6 carbon atoms, or a halogenated alkenil or alkeniloxy having 2 to 6 carbon atoms,

L ¹ and L ² represent F or Cl, preferably F,

L ^Q1 to L ^Q6 represent H, F or Cl, preferably H or F, wherein at least one of L ^Q1 to L ^Q6 represents F or Cl, preferably F,

L ^T1 to L ^T6 represent H, F or Cl, preferably H or F, wherein at least one of L ^T1 to L ^T6 represents F or Cl, preferably F]

A liquid crystal (LC) medium comprising: wherein the LC medium comprises at least one compound of formula S:

[In the above equation,

R ^{a -d} are, independently of each other, straight-chain or branched alkyl having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, very preferably 1 to 4 carbon atoms, most preferably methyl. represents,

X represents H, CH ₃ , OH or O ^ㆍ ,

A represents an optionally substituted straight-chain, branched or cyclic alkylene having 1 to 20 carbon atoms.

The liquid crystalline component B) of the LC medium according to the invention is hereinafter also referred to as “LC host mixture” and is preferably an LC compound selected from non-polymerizable low molecular weight compounds, such as compounds of formulas A, B and T. and optionally additives such as polymerization initiators, inhibitors, etc.

The invention also relates to LC media or LC displays described above and below, in which the polymerisable compounds of component A have been polymerized.

The invention also provides a combination of at least one compound of formula A, at least one compound of formula B and at least one compound of formula T or the LC host mixture or LC component B) described above and below, and at least one compound of formula S and mixing one or more polymerizable compounds, and optionally additional LC compounds and/or additives.

The invention also relates to the use of LC media in LC displays, especially PSA displays.

The invention also relates to the use of the LC medium according to the invention in PSA displays, in particular the use of the LC medium according to the invention by in situ polymerization of the polymerisable compounds of component B) in PSA displays, preferably under the application of an electric or magnetic field. It relates to use in PSA displays comprising LC media for producing tilt angles.

The invention also relates to LC displays comprising at least one compound of formula I or an LC medium according to the invention, in particular PSA displays, very preferably PS-VA, PS-IPS or PS-UB-FFS displays.

The invention also relates to an LC display comprising at least one compound of formula I or a polymer obtainable by the above-described polymerizable component A) or comprising an LC medium according to the invention, which is preferably PSA A display, very preferably a PS-VA, PS-IPS or PS-UB-FFS display.

The invention also relates to an LC display of the PSA type, comprising two substrates, at least one of which is optically transparent, two electrodes provided on each substrate or only on one of the two substrates, and characterized in that it comprises a layer of LC medium comprising an LC component and one or more polymerisable compounds described above and below, positioned between the substrates, wherein the polymerisable compound is polymerized between the substrates of the display. .

The present invention also provides a method for forming a LC medium comprising one or more polymerizable compounds described above and below, comprising the steps of packing or otherwise providing between the substrates of a display and polymerizing the polymerizable compounds. It relates to a method of manufacturing the described LC display.

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

In a preferred embodiment, the polymerizable component polymerizes in the LC display while a voltage is applied to the electrodes of the display.

The polymerizable compound of the polymerizable component is preferably polymerized by photopolymerization, very preferably by UV photopolymerization.

Unless otherwise stated, the polymerisable compounds and RM are preferably selected from achiral compounds.

As used herein, the terms "active layer" and "switchable layer" refer to one or more molecules having a structure and optical anisotropy that change orientation upon external stimulation, such as an electric or magnetic field, thereby changing the transmittance of the layer for polarized or unpolarized light. , e.g., a layer within an electro-optical display, such as an LC display, comprising LC molecules.

As used herein, the term “tilt” or “tilt angle” will be understood to mean an inclined orientation of the LC molecules in the LC medium relative to the surface of the cell in the LC display (preferably here a PSA display). The tilt angle herein refers to the average angle (less than 90°) between the longitudinal molecular axis of the LC molecule (LC director) and the plane-parallel outer plate surfaces forming the LC cell. Low values of inclination angles (i.e. large deviations from the 90° angle) correspond here to large inclinations. A suitable method for measuring the tilt angle is given in the examples below. Unless otherwise stated, the tilt angle values described above and below relate to this measurement method.

As used herein, the terms "reactive mesogen" and "RM" refer to a compound comprising a mesogenic or liquid crystalline framework and one or more functional groups attached thereto (suitable for polymerization, also referred to as "polymerizable groups" or "P"). It will be understood to mean.

Unless otherwise stated, the term “polymerisable compound” will be understood herein to mean a polymerisable monomeric compound.

As used herein, the term “low molecular weight compound”, as opposed to “polymeric compound” or “polymer”, will be understood to mean a compound that is monomeric and/or has not been prepared by polymerization.

“Non-polymerizable compounds” will be understood herein to mean compounds that do not contain functional groups suitable for polymerization under the conditions normally applied for the polymerization of RMs.

As used herein, the term "mesogenic group" is known to those skilled in the art and described in the literature and is essential for directing the liquid crystal (LC) phase to a low molecular weight or polymeric material due to the anisotropy of attractive and repulsive interactions. It means that it contributes to . Compounds containing mesogenic groups (mesogenic compounds) do not necessarily have to have an LC phase per se. It is also possible that mesogenic compounds exhibit LC phase behavior only after mixing and/or polymerization with other compounds. Typical mesogenic groups are, for example, hard rod- or disk-shaped units. For an overview of terms and definitions used in relation to mesogenic or LC compounds, see Pure Appl. Chem. 2001, 73(5), 888] and [C. Tschierske, G. Pelzl, S. Diele, and Angew. Chem. 2004, 116, 6340-6368].

The term “spacer group”, hereinafter also referred to as “Sp”, is known to those skilled in the art and is described in, for example, Pure Appl. Chem. 2001, 73(5), 888] and [C. Tschierske, G. Pelzl, S. Diele, and Angew. Chem. 2004, 116, 6340-6368]. The term “spacer group” or “spacer” herein refers to a flexible group, such as an alkylene group, linking a mesogenic group and a polymerizable group(s) in a polymerizable mesogenic compound.

Above and below,

는 트랜스-1,4-사이클로헥실렌 고리를 나타내고,

represents a trans-1,4-cyclohexylene ring,

는 1,4-페닐렌 고리를 나타낸다.

represents a 1,4-phenylene ring.

“Organic group” above and below refers to a carbon or hydrocarbon group.

“Carbon group” refers to a monovalent or multivalent organic group comprising one or more carbon atoms, which may contain no additional atoms (e.g., -C≡C-), or optionally one or more additional atoms, such as N, Contains O, S, B, P, Si, Se, As, Te or Ge (e.g. carbonyl, etc.). The term “hydrocarbon group” refers to a carbon group that additionally comprises one or more H atoms and optionally one or more heteroatoms such as N, O, S, B, P, Si, Se, As, Te or Ge.

“Halogen” refers to F, Cl, Br or I.

"O ^· " represents an oxygen radical.

를 나타낸다.-CO-, -C(=O)- and -C(O)- are carbonyl groups, i.e.

represents.

The carbon or hydrocarbon group may be saturated or unsaturated. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. Carbon or hydrocarbon groups having more than 3 carbon atoms can be straight chain, branched and/or cyclic, and can also include spiro bonds or condensed rings.

The terms “alkyl,” “aryl,” “heteroaryl,” and the like also encompass multivalent groups such as alkylene, arylene, heteroarylene, and the like.

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

Preferred carbon and hydrocarbon groups are straight-chain, branched or cyclic, alkyl, alkenyl, optionally substituted and having 1 to 40, preferably 1 to 20, very preferably 1 to 12 carbon atoms, Alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy, optionally substituted aryl or aryloxy having 5 to 30 carbon atoms, preferably 6 to 25 carbon atoms, or 5 optionally substituted alkylaryl, aryl-alkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, aryl-carbonyloxy and having from 30 to 30 carbon atoms, preferably from 6 to 25 carbon atoms. represents aryloxy-carbonyloxy, wherein one or more carbon atoms may also be replaced by a heteroatom, preferably selected from N, O, S, Se, Te, Si and Ge.

Further preferred carbon and hydrocarbon groups are C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ alkynyl, C ₃ -C ₂₀ aryl, C ₄ -C ₂₀ alkyldienyl, C ₄ - C ₂₀ polyenyl, C ₆ -C ₂₀ cycloalkyl, C ₄ -C ₁₅ cycloalkenyl, C ₆ -C ₃₀ aryl, C ₆ -C ₃₀ Alkylaryl, C ₆ -C ₃₀ Arylalkyl, C ₆ -C ₃₀ Alkylaryloxy, C ₆ -C ₃₀ Aryl-alkyloxy, C ₂ -C ₃₀ heteroaryl, C ₂ -C ₃₀ heteroaryloxy.

Particularly preferred are C ₁ -C ₁₂ alkyl, C ₂ -C ₁₂ alkenyl, C ₂ -C ₁₂ alkynyl, C ₆ -C ₂₅ aryl and C ₂ -C ₂₅ heteroaryl.

Further preferred carbon and hydrocarbon groups are straight-chain, branched, having 1 to 20, preferably 1 to 12 carbon atoms, which may be unsubstituted or mono- or polysubstituted with F, Cl, Br, I or CN. represents chain or cyclic alkyl, wherein one or more non-adjacent CH ₂ groups are, independently of each other, in such a way that the O and/or S atoms are not directly connected to each other -C(R ^x )=C(R ^x )-, -C ≡C-, -N(R ^x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-.

^R -CO-, -CO-O-, -O-CO-, -O-CO-O- and one or more H atoms may be replaced by F or Cl), or 6 to 30 carbon atoms represents an optionally substituted aryl or aryloxy group having 2 to 30 carbon atoms or an optionally substituted heteroaryl or heteroaryloxy group.

Preferred alkyl groups are such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclo-pentyl, n- Hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecanyl, trifluoro-methyl , perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluoro-hexyl, etc.

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

Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.

Preferred alkoxy groups are such as methoxy, ethoxy, 2-methoxy-ethoxy, 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, etc.

Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, etc.

Aryl and heteroaryl groups can be monocyclic or polycyclic. That is, they contain one ring (e.g. phenyl), two or more rings that can also be fused (e.g. naphthyl), two or more rings that can be covalently bonded (e.g. biphenyl), or combinations of fused and linked rings. may include. Heteroaryl groups preferably contain one or more heteroatoms selected from O, N, S and Se.

Particularly preferred are mono-, di- or tricyclic aryl groups having 6 to 25 carbon atoms, optionally comprising fused rings and optionally substituted, and mono-, di- aryl groups having 5 to 25 ring atoms. or a tricyclic heteroaryl group. Also preferred are 5-, 6- or 7-membered aryl and heteroaryl groups, wherein one or more CH groups may also be replaced by N, S or O in such a way that the O and/or S atoms are not directly connected to each other. You can.

Preferred aryl groups are such as phenyl, biphenyl, terphenyl, [1,1':3',1"]terphenyl-2'-yl, naphthyl, anthracene, binapthyl, phenanthrene, 9,10-di Hydro-phenanthrene, pyrene, dihydropyrene, chrysene, perylene, tetracene, pentacene, benzo-pyrene, fluorene, indene, indenofluorene, spirobifluorene, etc.

Preferred heteroaryl groups are, for example, 5-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophen, oxa Sol, 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-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 6 -One ring, 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, 1,2,3,5-tetrazine, or condensing groups such as indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, purine , naphthymidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoxaline imidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran , isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine, Phenothiazine, phenoxazine, benzo-pyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno-[2,3b]- Thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzo-thiophene, dibenzothiophene, benzothiadiazothiophene, or a combination of these groups.

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.

The above (non-aromatic) alicyclic and heterocyclic groups encompass both saturated rings, i.e. those containing only single bonds, and partially unsaturated rings, i.e. which may also contain multiple bonds. The heterocyclic ring preferably contains one or more heteroatoms selected from Si, O, N, S and Se.

The (non-aromatic) alicyclic and heterocyclic groups may be monocyclic, having only one ring (e.g. cyclohexane), or polycyclic containing multiple rings (e.g. decahydro-naphthalene or bicyclooctane). . Particular preference is given to saturating groups. Preference is also given to mono-, di- or tricyclic groups having 5 to 25 ring atoms, optionally comprising fused rings and optionally substituted. Preference is also given to 5-, 6-, 7- or 8-membered carbocyclic groups, wherein one or more carbon atoms can also be replaced by Si and/or one or more CH groups can be replaced by N and/or Alternatively, one or more non-adjacent CH ₂ groups may be replaced by -O- and/or -S-.

Preferred cycloaliphatic and heterocyclic groups include, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, pyrrolidine, 6-membered groups such as cyclohexane, silinane, cyclohexene, tetrahydropyran, Tetrahydrothiopyran, 1,3-dioxane, 1,3-dithian, 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, octahydro-4 ,7-Methanoindan-2,5-diyl.

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

Preferred substituents, hereinafter also referred to as "L", are 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 , straight or branched chain alkyl, alkoxy, alkylcarbo, each having 1 to 25 carbon atoms Nyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, wherein one or more H atoms may be optionally substituted with F or Cl, optionally substituted silyl having 1 to 20 silicon atoms, or 6 represents an optionally substituted aryl having from 25 to 25 carbon atoms, preferably from 6 to 15 carbon atoms,

In this case _, ^R In a manner that is not directly linked, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be replaced, and one or more H atoms each may be optionally replaced by F, Cl, P- or P-Sp-),

Y ¹ represents halogen.

“Unsubstituted silyl or aryl” is preferably halogen, -CN, R ⁰ , -OR ⁰ , -CO-R ⁰ , -CO-OR ⁰ , -O-CO-R ⁰ or -O-CO- OR ⁰ means substituted, where R ⁰ represents H or alkyl having 1 to 20 carbon atoms.

Particularly preferred substituents L are, for example, F, Cl, CN, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ , is also phenyl.

는 바람직하게는

이고, 이때 L은 상기 기재된 의미 중 하나를 갖는다.

is preferably

, where L has one of the meanings described above.

The polymerisable group P is a group suitable for polymerization reactions, such as free-radical or ionic chain polymerization, polyaddition or polycondensation, or polymer-like reactions, such as addition or condensation on the main polymer chain. Particular preference is given to groups for chain polymerization, especially those containing C=C double bonds or -C≡C- triple bonds, and groups suitable for ring-opening polymerization, such as oxetane or epoxide groups.

, CH₂=CW²-(O)_k3-, CW¹=CH-CO-(O)_k3-, CW¹=CH-CO-NH-, CH₂=CW¹-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-CW²W³-, HS-CW²W³-, HW²N-, HO-CW²W³-NH-, CH₂=CW¹-CO-NH-, CH₂=CH-(COO)_k1-Phe-(O)_k2-, CH₂=CH-(CO)_k1-Phe-(O)_k2-, Phe-CH=CH-, HOOC-, OCN- 및 W⁴W⁵W⁶Si-로 이루어진 군으로부터 선택되고,Preferred groups P are CH ₂ =CW ¹ -CO-O-, CH ₂ =CW ¹ -CO-,

, CH ₂ =CW ² -(O) _k3 -, CW ¹ =CH-CO-(O) _k3 -, CW ¹ =CH-CO-NH-, CH ₂ =CW ¹ -CO-NH-, CH ₃ - CH=CH-O-, (CH ₂ =CH) ₂ CH-OCO-, (CH ₂ =CH-CH ₂ ) ₂ CH-OCO-, (CH ₂ =CH) ₂ CH-O-, (CH ₂ = CH-CH ₂ ) ₂ N-, (CH ₂ =CH-CH ₂ ) ₂ N-CO-, HO-CW ² W ³ -, HS-CW ² W ³ -, HW ² N-, HO-CW ² W ³ -NH-, CH ₂ =CW ¹ -CO-NH-, CH ₂ =CH-(COO) _k1 -Phe-(O) _k2 -, CH ₂ =CH-(CO) _k1 -Phe-(O) _k2 -, Phe-CH=CH-, HOOC-, OCN- and W ⁴ W ⁵ W ⁶ Si-,

At this time, W ¹ represents H, F, Cl, CN, CF ₃ , phenyl or alkyl having 1 to 5 carbon atoms, especially H, F, Cl or CH ₃ , and W ² and W ³ are each independently of each other. , H or an alkyl having 1 to 5 carbon atoms, especially H, methyl, ethyl or n-propyl, and W ⁴ , W ⁵ and W ⁶ each, independently of one another, represent Cl, having 1 to 5 carbon atoms. represents oxaalkyl or oxacarbonylalkyl having, W ⁷ and W ⁸ each independently represent H, Cl or alkyl having 1 to 5 carbon atoms, and Phe represents, except for P-Sp- represents 1,4-phenylene optionally substituted with one or more radicals L as defined above, k ₁ , k ₂ and k ₃ independently of each other represent 0 or 1, and k ₃ preferably represents 1 , k ₄ represents an integer from 1 to 10.

, CH₂=CW²-O-, CH₂=CW²-, CW¹=CH-CO-(O)_k3-, CW¹=CH-CO-NH-, CH₂=CW¹-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=CW¹-CO-NH-, CH₂=CH-(COO)_k1-Phe-(O)_k2-, CH₂=CH-(CO)_k1-Phe-(O)_k2-, Phe-CH=CH- 및 W⁴W⁵W⁶Si-로 이루어진 군으로부터 선택되고,Very preferred groups P are CH ₂ =CW ¹ -CO-O-, CH ₂ =CW ¹ -CO-,

, CH ₂ =CW ² -O-, CH ₂ =CW ² -, CW ¹ =CH-CO-(O) _k3 -, CW ¹ =CH-CO-NH-, CH ₂ =CW ¹ -CO-NH- , (CH ₂ =CH) ₂ CH-OCO-, (CH ₂ =CH-CH ₂ ) ₂ CH-OCO-, (CH ₂ =CH) ₂ CH-O-, (CH ₂ =CH-CH ₂ ) ₂ N-, (CH ₂ =CH-CH ₂ ) ₂ N-CO-, CH ₂ =CW ¹ -CO-NH-, CH ₂ =CH-(COO) _k1 -Phe-(O) _k2 -, CH ₂ = CH-(CO) _k1 -Phe-(O) _k2 -, Phe-CH=CH- and W ⁴ W ⁵ W ⁶ Si-,

At this time, W ¹ represents H, F, Cl, CN, CF ₃ , phenyl or alkyl having 1 to 5 carbon atoms, especially H, F, Cl or CH ₃ , and W ² and W ³ are each independently of each other. , H or an alkyl having 1 to 5 carbon atoms, especially H, methyl, ethyl or n-propyl, and W ⁴ , W ⁵ and W ⁶ each, independently of one another, represent Cl, having 1 to 5 carbon atoms. represents oxaalkyl or oxacarbonylalkyl having, W ⁷ and W ⁸ each independently represent H, Cl or alkyl having 1 to 5 carbon atoms, Phe represents 1,4-phenylene, k ₁ , k ₂ and k ₃ independently of each other represent 0 or 1, k ₃ preferably represents 1, and k ₄ represents an integer of 1 to 10.

로 이루어진 군으로부터 선택된다.Very particularly preferred groups P are CH ₂ =CW ¹ -CO-O-, especially CH ₂ =CH-CO-O-, CH ₂ =C(CH ₃ )-CO-O- and CH ₂ =CF-CO-O. -, also CH ₂ =CH-O-, (CH ₂ =CH) ₂ CH-O-CO-, (CH ₂ =CH) ₂ CH-O-,

is selected from the group consisting of

Further preferred polymerisable groups P are selected from the group consisting of vinyloxy, acrylates, methacrylates, fluoroacrylates, chloroacrylates, oxetanes and epoxides, most preferably acrylates and methacrylates.

If the spacer group Sp differs from the single bond, this is preferably of the formula Sp"-X", so that the individual radicals P-Sp- correspond to the formula P-Sp"-X"-, where

Sp" is an alkenyl group having 1 to 20, preferably 1 to 12 carbon atoms, optionally mono- or polysubstituted with F, Cl, Br, I or CN, wherein one or more non-adjacent CH _{The two} groups can also be, each independently of one another, -O-, -S-, -NH-, -N(R ⁰ )-, -Si(R ⁰ R ⁰⁰⁾ in such a way that the O and/or S atoms are not directly connected to each other. )-, -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 )-, -OCH ₂ -, -CH ₂ O-, -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, - OCF ₂ -, -CF ₂ S-, -SCF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CF ₂ CF ₂ -, -CH=N-, -N=CH-, -N =N-, -CH=CR ⁰ -, -CY ² =CY ³ -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or represents a single bond,

R ⁰ and R ⁰⁰ each independently represent H or alkyl having 1 to 20 carbon atoms,

Y ² and Y ³ each independently represent H, F, Cl, or CN.

X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR ⁰ -, -NR ⁰ -CO-, -NR ⁰ - CO-NR ⁰⁰ - or a single bond.

Typical spacer groups Sp and -Sp"-X"- are, for example -(CH ₂ ) _p1 -, -(CH ₂ CH ₂ O) _q1 -CH ₂ CH ₂ -, -CH ₂ CH ₂ -S-CH ₂ CH ₂ -, -CH ₂ CH ₂ -NH-CH ₂ CH ₂ - or -(SiR ⁰ R ⁰⁰ -O) _p1 -, where p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R ⁰ and R ⁰⁰ have the meanings described above.

Particularly preferred groups Sp and -Sp"-X"- are -(CH ₂ ) _p1 -, -(CH ₂ ) _p1 -O-, -(CH ₂ ) _p1 -O-CO-, -(CH ₂ ) _p1 - CO-O-, or -(CH ₂ ) _p1 -O-CO-O-, where p1 and q1 have the meanings described above.

Particularly preferred groups Sp" are, in each case, straight chain, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxy. They are ethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

In compounds of formula S, R ^{a -d} preferably represents methyl or ethyl, very preferably methyl.

In compounds of formula S, A preferably represents a straight-chain alkylene of 1 to 20 carbon atoms, a branched alkylene of 2 to 20 carbon atoms, or a cyclic alkylene of 3 to 20 carbon atoms, all of which is optionally substituted with one or more groups L ^A .

In compounds of formula S, A very preferably represents a straight-chain alkylene having 1 to 20 carbon atoms or a branched alkylene having 2 to 20 carbon atoms, all of which are optionally represented by one or more groups L ^A is replaced.

Preferred substituents L ^A are selected from F and straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy, each having 1 to 12 carbon atoms, wherein one or more The H atom may optionally be replaced by F or Cl.

In a first preferred embodiment of the invention, the compounds of formula S are selected from those wherein X is H or CH ₃ , preferably H.

In a first preferred embodiment of the invention, the compounds of formula S are selected from those wherein X is O ^· or OH, preferably O ^· .

In a first preferred embodiment of the invention, the compounds of formula S are selected from those where A is a branched alkylene having 2 to 20 carbon atoms, optionally substituted with one or more groups L ^A .

Preferred compounds of formula S are selected from the following subformulas S1 to S4:

In the above formula, n1 is an integer from 2 to 12, and one or more H-atoms in these radicals (CH ₂ ) _n1 are optionally replaced by methyl, ethyl, propyl, butyl, pentyl or hexyl groups.

Very preferred compounds of formula S are selected from the following subformulas S1a to S4a:

In a first preferred embodiment of the invention, the compounds of formula S are selected from those wherein X is H or CH ₃ , preferably H. Preferred compounds of this first preferred embodiment are those of the formulas S1 and S4 above and the sub-formulas S1a, S1b and S4a.

In a second preferred embodiment of the invention, the compounds of formula S are selected from those wherein X is O ^· or OH, preferably O ^· . Preferred compounds of this second preferred embodiment are those of the formulas S2 and S3 above and the sub-formulas S2a, S2b, S2c and S3a. Particularly preferred are compounds of formula S2a.

In a third preferred embodiment of the invention, the compounds of formula S are selected from those where A is a branched alkylene having 2 to 20 carbon atoms, optionally substituted with one or more groups L ^A . Preferred compounds of the second preferred embodiment are those of formula S5 and sub-formulas S1b and S2c.

In the above equation,

X is H, CH ₃ , OH or O ^ㆍ , preferably H or O ^ㆍ ,

R ^A is methyl, ethyl, propyl, butyl, pentyl or hexyl,

n2 is 0 or an integer from 1 to 12, preferably 0,

n3 is 0 or an integer from 1 to 12.

Preferred compounds of formula S5 are those of subformula S1b and S2c above.

Preferably, the proportion of formula S or a subformula thereof in the LC medium is 10 to 1000 ppm, very preferably 20 to 500 ppm.

Preferably, the LC medium contains 1 to 5, preferably 1, 2 or 3 compounds of formula S or sub-formulas thereof.

In another preferred embodiment of the invention, in addition to the compounds of formula S, the LC medium comprises one or more further stabilizers, preferably selected from the compounds of formula:

In the above formula, n is an integer from 1 to 6, preferably 3.

Preferably, the proportion of additional stabilizers, such as compounds of formula SC, in the LC medium is 10 to 500 ppm, very preferably 20 to 100 ppm.

Compounds of formula A are preferably selected from formula A1:

In the above formula, alkyl represents a straight-chain alkyl radical having 1 to 6 carbon atoms, and (O) represents an oxygen atom or a single bond. Very preferred are the compounds of formula A1, where (O) represents an oxygen atom and the alkyl is preferably straight chain methyl, ethyl, propyl, butyl, pentyl or hexyl.

Preferably, the proportion of compounds of formula A or A1 in the LC medium is 2 to 35%, very preferably 3 to 30% and most preferably 5 to 25%.

Preferably, the LC medium contains 1 to 5, preferably 1, 2 or 3 compounds of formula A or A1.

Compounds of formula B are preferably selected from formula B1:

In the above formula, alkyl represents a straight-chain alkyl radical having 1 to 6 carbon atoms, and (O) represents an oxygen atom or a single bond. Very preferred are compounds of formula B1, wherein both groups (O) represent oxygen atoms and the alkyl is preferably straight chain methyl, ethyl, propyl, butyl, pentyl or hexyl.

Preferably, the compound of formula B or B1 in the LC medium is 0.5 to 20%, very preferably 1 to 15% and most preferably 1 to 10%.

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

Compounds of formula T are preferably selected from the following subformulas T1 to T24:

In the above formula, R represents a straight-chain alkyl or alkoxy radical having 1 to 7 carbon atoms, R ^* represents a straight-chain alkenyl radical having 2 to 7 carbon atoms, (O) represents an oxygen atom or a single bond, and , m represents an integer from 1 to 6. R ^* is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH =CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

R and R ^* preferably represent methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.

Very preferred are those of the formulas T1, T2 and T3, especially those of the formulas T1 and T2.

Very preferred are the compounds of the formulas T1 to T24, wherein (O) represents an oxygen atom, m is 1, 2, 3, 4 or 5 and R is methyl, ethyl, propyl, butyl, preferably straight chain. , pentyl or hexyl.

Preferably, the LC medium does not contain more than 15% of compounds of formula T or T1 to T24 or any other compounds having terphenyl groups.

Preferably, the proportion of compounds of formula T or T1 to T24 or any other compounds with terphenyl groups in the LC medium is 0.5 to 15%, very preferably 1 to 10%. In another preferred embodiment, the proportion of compounds of formula T or T1 to T24 or any other compounds having terphenyl groups in the LC medium is 5 to 15%, very preferably 5 to 10%.

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

In an LC medium according to the invention, an LC host mixture comprising compounds of formulas A, B and T is polymerized, comprising at least one stabilizer of formula S and preferably di- and/or tri-reactive RMs. Use with aqueous components leads to advantageous properties in PSA displays. In particular, one or more of the following advantages can be achieved:

- Excellent UV absorption even at longer wavelengths,

- rapid and complete polymerization of RM,

- rapid occurrence of low pretilt angles, especially at low UV energies and/or longer UV wavelengths, especially in advance,

- High UV absorption,

- increased UV stability,

- High pretilt angle stability after UV exposure,

- Reduced afterimage,

- Reduced ODF staining,

- High reliability and high VHR values after UV exposure and/or heat treatment,

- High birefringence,

- reduced viscosity, and

- Faster response time.

Since the LC media according to the invention shows high absorption at longer UV wavelengths, it is possible to use longer UV wavelengths for polymerization, which is advantageous for the display manufacturing process.

The polymerisable compound is preferably selected from the formula (I):

R ^a -B ¹ -(Z ^b -B ² ) _m -R ^b I

In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:

R ^a and R ^b are P, P-Sp-, H, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, SF ₅ or 1 to 25 represents a straight-chain or branched alkyl with a carbon atom, wherein one or more non-adjacent CH ₂ groups are also, independently of each other, in such a way that the O and/or S atoms are not directly connected to each other -C(R ⁰ )=C( R ⁰⁰ )-, -C≡C-, -N(R ⁰⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be replaced with, wherein one or more H atoms may also be replaced with F, Cl, Br, I, CN, P or P-Sp-, and B ¹ and/or B ² contain a saturated carbon atom. In this case, R ^a and/or R ^b may also represent a radical spiro-linked to the saturated carbon atom,

wherein at least one of the radicals R ^a and R ^b represents or contains the group P or P-Sp,

P is a polymerizable group,

Sp is a spacer group or single bond,

B ¹ and B ² represent an aromatic, heteroaromatic, alicyclic or heterocyclic group, which may comprise a fused ring and is unsubstituted or mono- or poly-substituted with L, preferably having 4 to 25 ring atoms. represents,

Z ^b is -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 represents a single bond ,

R ⁰ and R ⁰⁰ represent H or alkyl having 1 to 12 carbon atoms,

m represents 0, 1, 2, 3 or 4,

n1 represents 1, 2, 3 or 4,

L is 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 carbon atoms. , or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxy-carbonyloxy having 1 to 25 carbon atoms, wherein one or more H atoms are also F, may be replaced by Cl, P or P-Sp-,

P and Sp have the meanings described above,

Y ¹ represents halogen,

^R _{_} may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and one or more H atoms may also be replaced by , Cl, P or P-Sp-), an optionally substituted aryl or aryloxy group having 6 to 40 carbon atoms, or an optionally substituted hetero-aryl having 2 to 40 carbon atoms. or hetero-aryloxy group.

Particularly preferred compounds of formula I are those in which B ¹ and B ² are: Each independently of the other, 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 (wherein one or more CH groups in these groups are also N may be replaced), cyclohexane-1,4-diyl (wherein one or more non-adjacent CH ₂ groups may also be replaced by O and/or S), 1,4-cyclohexenylene, bicycle- [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, decahydro-naphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indan-2,5-diyl or octahydro-4 , 7-methanoindan-2,5-diyl (wherein all these groups may be unsubstituted or mono- or poly-substituted with L as defined above).

Particularly preferred compounds of formula I are those in which B ¹ and B ² are each, independently of one another, 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl or naphthalene-2,6-diyl. These are things that represent work.

Very preferred compounds of formula I are selected from the formula:

In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:

P ¹ , P ² and P ³ represent vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane or epoxy group,

Sp ¹ , Sp ² and Sp ³ represent a single bond or spacer group, where one or more of the radicals P ¹ -Sp ¹ -, P ¹ -Sp ² - and P ³ -Sp ³ - can also represent R ^aa . provided that at least one of the radicals P ¹ -Sp ¹ -, P ² -Sp ² and P ³ -Sp ³ - present is different from R ^aa ,

R ^aa is H, F, Cl, CN or a straight-chain or branched alkyl having 1 to 25 carbon atoms, wherein one or more non-adjacent CH ₂ groups are also, each independently of one another, O and/or S atoms directly adjacent to each other. In a non-connected manner, -C(R ⁰ )=C(R ^{0 0} )-, -C≡C-, -N(R ⁰ )-, -O-, -S-, -CO-, -CO-O -, -O-CO-, -O-CO-O-, where one or more H atoms can also be replaced by F, Cl, CN or P ¹ -Sp ¹ -), in particular Alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, preferably having 1 to 12 carbon atoms, straight chain or branched, optionally mono- or polyfluorinated. Represents alkoxycarbonyloxy (wherein the alkenyl and alkynyl radicals have 2 or more carbon atoms and the branched radical has 3 or more carbon atoms),

R ⁰ and R ⁰⁰ represent H or alkyl having 1 to 12 carbon atoms,

R ^y and R ^z represent H, F, CH ₃ or CF ₃ ,

X ¹ , X ² and X ³ represent -CO-O-, -O-CO- or a single bond,

Z ¹ represents -O-, -CO-, -C(R ^y R ^z )- or -CF ₂ CF ₂ -,

Z ² and Z ³ represent -CO-O-, -O-CO-, -CH ₂ O-, -OCH ₂ -, -CF ₂ O-, -OCF ₂ - or -(CH ₂ ) _n -, In this case, n is 2, 3, or 4,

L is F, Cl, CN or straight-chain or branched alkyl having 1 to 12 carbon atoms, optionally mono- or polyfluorinated, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkyl Represents carbonyloxy or alkoxycarbonyloxy,

L' and L" represent H, F or Cl,

r represents 0, 1, 2, 3 or 4,

s represents 0, 1, 2 or 3,

t represents 0, 1 or 2,

x represents 0 or 1.

Particularly preferred are the compounds of formula M2 and M13.

Further preference is given to the trireactive compounds M15 to M30, especially M17, M18, M19, M22, M23, M24, M25, M29 and M30.

In compounds of formula M1 to M30,

는 바람직하게는

이고,energy

is preferably

ego,

At this time, L has the meaning given above or below, identically or differently in each case, and is preferably F, Cl, CN, NO ₂ , CH ₃ , C ₂ H ₅ , C(CH ₃ ) ₃ , CH(CH ₃ ) ₂ , CH ₂ CH(CH ₃ )C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ or P-Sp-, very preferably F, Cl, CN, CH ₃ , C ₂ H ₅ , OCH ₃ , COCH ₃ , OCF ₃ or P-Sp-, more preferably F , Cl, CH ₃ , OCH ₃ , COCH ₃ or OCF ₃ , especially F or CH ₃ .

Preferred compounds of formula M1 to M30 are those in which P ¹ , P ² and P ³ represent acrylate, methacrylate, oxetane or epoxy groups, very preferably acrylate or methacrylate groups.

Further preferred compounds of formula M1 to M30 are those in which Sp ¹ , Sp ² and Sp ³ are single bonds.

Further preferred compounds of formula M1 to M30 are those in which one of Sp ¹ , Sp ² and Sp ³ is a single bond and the other of Sp ¹ , Sp ² and Sp ³ is different from a single bond.

Further preferred compounds of the formula M1 to M30 are those in which the groups Sp ¹ , Sp ² and Sp ³ different from the single bond represent -(CH ₂ ) _s1 -X"-, wherein s1 is 1 to 6, preferably 2, is an integer of 3, 4 or 5, and

Particularly preferred are LC media comprising one, two or three polymerisable compounds of formula (I).

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

Combining the polymerizable compounds of formulas M1 to M30 with compounds of formulas B, Q and T results in rapid and complete polymerization, rapid development of stable low pretilt angles after UV exposure, and at the same time high reliability and high VHR values after UV exposure. This leads to advantageous behavior of the LC medium, which is achieved together with the refractive index. Moreover, the LC media exhibits high absorption at longer UV wavelengths, and therefore it is possible to use these longer UV wavelengths for polymerization, which is advantageous in the display manufacturing process.

For the production of PSA displays, the polymerizable compounds included in the LC medium are polymerized or cross-linked by polymerizing in situ in the LC medium between the substrates of the LC display, optionally while applying a voltage to the electrodes (one compound if it contains two or more polymerizable groups).

The structure of the PSA display according to the invention corresponds to the conventional geometric PSA display described in the prior art cited at the beginning. Geometries without protrusions are preferred, especially those where the electrodes on the color filter side are unstructured and only the electrodes on the TFT side have slots. Particularly suitable and preferred electrode structures for PS-VA displays are described, for example, in US 2006/0066793 A1.

Preferred PSA type LC displays of the present invention include:

- a pixel electrode defining a pixel area, wherein the pixel electrode is connected to a switching element disposed in each pixel area and optionally includes a micro-slit pattern, and a first orientation layer optionally disposed on the pixel electrode. Comprising a first substrate,

- a second substrate, comprising a conventional electrode layer that can be disposed entirely on the second substrate facing the first substrate, and optionally a second orientation layer,

- an LC disposed between the first and second substrates and comprising an LC medium comprising the polymerisable component A and the liquid crystal component B described above and below, wherein the polymerisable component A may also be polymerized. floor.

The first and/or second alignment layer controls the orientation direction of the LC molecules in the LC layer. For example, in PS-VA displays, the orientation layer is selected to give the LC molecules homeotropic (or perpendicular) orientation (i.e., perpendicular to the surface) or oblique orientation. This orientation layer may comprise, for example, polyimide, which may also be rubbed, or may be produced by photoalignment methods.

The LC layer with LC medium can be deposited between the substrates of the display by methods commonly used by display manufacturers, such as the so-called liquid crystal dropping (ODF) method. The polymerisable component of the LC medium is then polymerized, for example by UV photopolymerization. The polymerization may be performed in one step or two or more steps.

The PSA display may include additional elements such as color filters, black matrices, passivation layers, optical delay layers, transistor elements for addressing individual pixels, etc., all of which are well known to those skilled in the art and are inventive. It can be used even without phosphor technology.

The electrode structure can be designed by a person skilled in the art depending on the individual display type. For example, in the case of PS-VA displays, multi-domain orientation of LC molecules can be induced by providing electrodes with slits and/or bumps or protrusions to create two, four or more different tilt orientation directions. You can.

Upon polymerization, the polymerizable compounds form cross-linked polymers, which cause a specific 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 will phase-separate or deposit from the LC medium and form a polymer layer on the substrate or electrode, or an orientation layer provided thereon. Microscopic data (such as SEM and AFM) confirmed that at least a portion of the formed polymer accumulated at the LC/substrate interface.

The polymerization can be performed in one step. In addition, it is also possible to first perform polymerization by arbitrarily applying a voltage to provide a pretilt angle in the first step, and then polymerize or cross-link the compounds that did not react in the first step in the second polymerization step without applying voltage. Do (“end curing”).

Suitable and preferred polymerization methods are, for example, thermal polymerization or photopolymerization, preferably photopolymerization, especially UV induced photopolymerization, which can be achieved by exposing the polymerisable compound to UV radiation.

Optionally one or more polymerization initiators are added to the LC medium. Suitable conditions for polymerization and suitable types and amounts of initiators are known to those skilled in the art and are described in the literature. Suitable for free-radical polymerization are, for example, the commercially available photoinitiators Irgacure 651 ^® , Irgacure 184 ^® , Irgacure 907 ^® , Irgacure 369 ^® or Darocure 1173 ^® (Ciba). Ciba AG). If a polymerization initiator is used, its proportion is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.

The polymerisable compounds according to the invention are also suitable for polymerization without initiators, which entails significant advantages, such as lower material costs and less contamination of the LC medium, in particular by possible residual amounts of the initiator or its decomposition products. Therefore, polymerization can also be carried out without adding an initiator. Accordingly, in a preferred embodiment, the LC medium does not contain a polymerization initiator.

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

The polymerisable compounds of formula (I) show excellent UV absorption and are therefore particularly suitable for processes for producing PSA displays comprising one or more of the following features:

- exposing the polymerizable medium to UV light in a display in two steps, e.g. a first UV exposure step to generate the tilt angle (“UV-1 step”) and a second UV exposure step to complete polymerization (“UV-1 step”) -Step 2")),

- exposing the polymerizable medium to UV light within the display generated by power-saving UV lamps (also known as “green UV lamps”), which have a relatively high absorption spectrum in their absorption spectrum of 300 to 380 nm. can be characterized by low intensity (typical UV1 lamps from 1/100 to 1/10) and are preferably used in the UV2 stage, but are also optionally used in the UV1 stage if it is necessary for the method to avoid high intensities) , and

- The polymerizable medium is exposed in the display to UV light generated by a UV lamp with an irradiation spectrum switched to a longer wavelength, preferably 340 nm or more, to avoid short UV light exposure in the PS-VA process. To do something.

By using both lower intensities and UV conversion to longer wavelengths, the organic layer is protected from damage that can be caused by UV light.

A preferred embodiment of the present invention relates to a method of manufacturing a PSA display described above and below comprising one or more of the following features:

- exposing the polymerizable medium to UV light in a display in two steps, e.g. a first UV exposure step to generate the tilt angle (“UV-1 step”) and a second UV exposure step to complete polymerization (“UV-1 step”) -Step 2")),

- the polymerizable LC medium is irradiated by a UV lamp with an intensity of 0.5 mW/cm ² to 10 mW/cm ² in the wavelength range of 300 to 380 nm, preferably used in the UV2 stage and optionally also used in the UV1 stage. exposing to generated UV light, and

- exposing the polymerizable LC medium to UV light with a wavelength of 340 nm or more, preferably 400 nm or less.

The preferred method uses, for example, a preferred UV lamp or a band pass filter and /Or it can be performed using a cut-off filter. For example, if irradiation with UV light of a wavelength λ of 300 to 400 nm is desired, the UV exposure may be performed using a broadband filter substantially transparent to the wavelength 300 nm < λ < 400 nm. If it is desirable to irradiate with UV light of a wavelength λ greater than 340 nm, the UV exposure may be performed using a cutoff filter that is substantially transparent to a wavelength λ greater than 340 nm.

“Substantially transmissive” means that the filter passes a substantial portion of the incident light of the desired wavelength, preferably at least 50% of the intensity. “Substantially blocking” means that the filter does not pass a substantial portion of incident light of undesired wavelengths, preferably more than 50% of the intensity. “Desired (unwanted) wavelength” means, for example, in the case of a bandpass filter, a wavelength within (outside) a given range of λ values, and in the case of a cutoff filter, a wavelength above (below) a given λ value.

The preferred method allows the production of displays using longer UV wavelengths, thereby reducing or even avoiding the dangerous and harmful effects of short UV light components.

UV irradiation energy is generally 6 to 100 J depending on production process conditions.

Preferably the LC medium according to the invention essentially consists of polymerisable component A) and LC component B) (or LC host mixture) described above and below. However, the LC medium may further include, but is not limited to, comonomers, chiral dopants, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricants, dispersants, hydrophobizers, adhesives, flow improvers, anti-foaming agents, degassing agents. , diluents, reactive diluents, auxiliaries, colorants, dyes, pigments, and nanoparticles.

Preference is given to LC media in which the polymerisable component A) consists exclusively of polymerisable compounds of formula (I).

In another preferred embodiment, the polymerisable component A) comprises, in addition to the polymerisable compounds of formula (I), at least one further polymerisable compound (“comonomer”), preferably selected from RM.

Preferably, the proportion of polymerisable component A) in the LC medium is greater than 0 and less than 5%, very preferably greater than 0 and less than 1%, most preferably between 0.01 and 0.5%.

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%.

Suitable and preferred mesogenic comonomers may be selected from Table D below.

The LC medium according to the invention is an LC host mixture comprising at least one, preferably at least two LC compounds selected from the above-described polymerisable component A), as well as the LC component B), or non-polymerizable low molecular weight compounds. Includes. These LC compounds are selected to be stable and/or non-reactive to polymerization under the conditions applicable to the polymerization of the polymerizable compound.

Examples of these compounds are those of formulas A, B and T described above.

Preference is given to the LC medium in which the LC component B), or the LC host mixture, has a nematic LC phase and preferably does not have a chiral liquid crystalline phase.

Also preferred are achiral compounds of formula (I), which are given in the LC medium in which the compounds of components A and/or B are selected exclusively from the group consisting of achiral compounds.

The LC component B), or LC host mixture, is preferably a nematic LC mixture.

The LC medium and LC component B) or LC host mixture according to the invention preferably have negative dielectric anisotropy.

In a preferred embodiment of the invention, the LC component B) of the LC medium, or the LC host mixture, comprises, in addition to the compounds of formula A, one or more further mesogenic or LC compounds comprising straight-chain, branched or cyclic alkenyl groups. (hereinafter also referred to as an “alkenyl compound”), wherein the alkenyl group is stable to polymerization under the conditions used for polymerization of the Joulesable compound contained in the LC medium.

These further alkenyl compounds are preferably selected from the formulas AN and AY:

In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:

는

Is

를 나타내고,

represents,

는

Is

를 나타내고,

represents,

는

Is

를 나타내고,

represents,

R ^A1 represents alkenyl having 2 to 9 carbon atoms, or when at least one of rings X, Y and Z represents cyclohexenyl, it also represents one of the meanings of R ^A2 ,

R ^A2 is alkyl having 1 to 12 carbon atoms (where one or two non-adjacent CH ₂ groups are also -O-, -CH=CH-, -CO-, in such a way that the O atoms are not directly connected to each other, may be replaced with -OCO- or -COO-),

Z ^x is -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, preferably a single bond,

L ^1-4 represents H, F, Cl, OCF ³ , CF ₃ , CH _{3 , CH 2 F} or CHF ₂ H, preferably H, F or Cl,

x represents 1 or 2,

z represents 0 or 1.

Preferred compounds of formula AN and AY are those where R ^A2 is selected from ethenyl, propenyl, butenyl, pentenyl, hexenyl and heptenyl.

Further preferred compounds of formula AN and AY are those wherein L ¹ and L ² represent F, or one of L ¹ and L ² represents F and the other represents Cl, and L ³ and L ⁴ represent F, or , L ³ and L ⁴ , one of which represents F and the other represents Cl.

Compounds of formula AN are preferably selected from the following subformulas AN1 to AN12:

In the above formula, alkyl and alkyl ^* each, independently of one another, represent a straight-chain alkyl radical having 1 to 6 carbon atoms, and alkenyl and alkenyl ^* each, independently of one another, represent a straight-chain alkyl radical having 2 to 7 carbon atoms. Represents an alkenyl radical. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Very preferred compounds of formula AN are selected from the following subformulas AN1a to AN6a:

In the above formula, m represents 1, 2, 3, 4, 5 or 6, i represents 0, 1, 2 or 3, and R ^b1 represents H, CH ₃ or C ₂ H ₅ .

Very particularly preferred compounds of formula AN are selected from the following subformulas AN1a1 to AN1a5:

Most preferred are the compounds of formula AN1a2 and AN1a5.

Compounds of formula AY are preferably selected from the following subformulas AY1 to AY28:

In the above formula, alkyl and alkyl ^* each, independently of one another, represent a straight-chain alkyl radical having 1 to 6 carbon atoms, and alkenyl and alkenyl ^* each, independently of one another, represent a straight-chain alkyl radical having 2 to 7 carbon atoms. Represents an alkenyl radical. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Very preferred compounds of formula AY are selected from the following subformulas AY5a to AY11a:

In the above formula, m and n each independently represent 1, 2, 3, 4, 5 or 6, and alkenyl is CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH -, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ - represents.

The LC medium is preferably a compound containing a terminal vinyloxy group (-O-CH=CH ₂ ), especially a compound of the formula AN or AY where R ^A1 or R ^A2 is a terminal vinyloxy group (-O-CH=CH ₂ ) and does not include compounds of).

Preferably, the LC medium comprises an LC component B) based on compounds with negative dielectric anisotropy, or an LC host mixture. These LC media are particularly suitable for use in PS-VA and PS-UB-FFS displays. Particularly preferred embodiments of these LC media are those of a) to z):

a) LC medium comprising at least one compound of the formula CY and/or PY:

In the above equation,

a represents 1 or 2,

b represents 0 or 1,

는

또는

를 나타내고,

Is

or

represents,

R ¹ and R ² are each, independently of each other, an alkyl having 1 to 12 carbon atoms (where one or two non-adjacent CH ₂ groups are also -O-, - CH=CH-, -CO-, -OCO- or -COO-), preferably alkyl or alkoxy having 1 to 6 carbon atoms,

Z ^x and Z ^y are each independently of each other -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, preferably a single bond,

L ^{1 -4} each independently represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F, and CHF ₂ .

Preferably, both L ¹ and L ² represent F or one of L ¹ and L ² represents F and the other represents Cl, or both L ³ and L ⁴ represent F or L ³ and One of L ⁴ represents F and the other represents Cl.

Compounds of formula CY are preferably selected from the group consisting of the following subformulas CY1 to CY33:

In the above formula, a represents 1 or 2, alkyl and alkyl ^* each independently of the other represent a straight-chain alkyl radical having 1 to 6 carbon atoms, and alkenyl represents a straight-chain alkenyl radical having 2 to 6 carbon atoms. and (O) represents an oxygen atom or a single bond. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH= It represents CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Compounds of formula PY are preferably selected from the group consisting of the following subformulas PY1 to PY20:

In the above formula, alkyl and alkyl ^* each, independently of one another, represent a straight-chain alkyl radical having 1 to 6 carbon atoms, alkenyl represents a straight-chain alkenyl radical having 2 to 6 carbon atoms, and (O) is oxygen Represents an atom or a single bond. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH= It represents CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

b) LC medium further comprising at least one compound of formula ZK:

In the above equation,

는

Is

를 나타내고,

represents,

는

를 나타내고,

Is

represents,

R ³ and R ⁴ are each, independently of each other, an alkyl having 1 to 12 carbon atoms (where one or two non-adjacent CH ₂ groups are also -O-, - in such a way that the O atoms are not directly connected to each other) CH=CH-, -CO-, -O-CO- or -CO-O- may be replaced),

Z ^y is -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, preferably a single bond.

Compounds of formula ZK are preferably selected from the group consisting of the following subformulas ZK1 to ZK10:

In the above formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1 to 6 carbon atoms, and alkenyl represents a straight-chain alkenyl radical having 2 to 6 carbon atoms. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH= It represents CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Particularly preferred are compounds of formula ZK1.

Particularly preferred compounds of formula ZK are selected from the following subformulas ZK1a to ZK1c:

wherein the propyl, butyl and pentyl groups are straight chain groups.

Most preferred are compounds of formula ZK1a.

c) LC medium further comprising at least one compound of formula DK:

In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:

R ⁵ and R ⁶ are each, independently of each other, an alkyl having 1 to 12 carbon atoms (where one or two non-adjacent CH ₂ groups are also -O-, - CH=CH-, -CO-, -OCO- or -COO-), preferably alkyl or alkoxy having 1 to 6 carbon atoms,

는

를 나타내고,

Is

represents,

는

를 나타내고,

Is

represents,

e represents 1 or 2.

Compounds of formula DK are preferably selected from the group consisting of the following subformulas DK1 to DK12:

In the above formula, alkyl and alkyl ^* each, independently of one another, represent a straight-chain alkyl radical having 1 to 6 carbon atoms, and alkenyl represents a straight-chain alkenyl radical having 2 to 6 carbon atoms. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH= It represents CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

d) LC medium further comprising at least one compound of formula LY:

In the above equation,

는

Is

를 나타내고,

represents,

(only one or more ring F is different from cyclohexylene),

f represents 1 or 2,

R ¹ and R ² each, independently of one another, represent an alkyl having 1 to 12 carbon atoms, where one or two non-adjacent CH ₂ groups are also -O- in such a way that the O atoms are not directly connected to each other. , -CH=CH-, -CO-, -OCO- or -COO-,

Z ^x is -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, preferably a single bond.

L ¹ and L ² each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F, and CHF ₂ .

Preferably, both radicals L ¹ and L ² represent F, or one of the radicals L ¹ and L ² represents F and the other represents Cl.

Compounds of the formula LY are preferably selected from the group consisting of the following subformulas LY1 to LY24:

In the above formula, R ¹ has the meaning described above, alkyl represents a straight-chain alkyl radical having 1 to 6 carbon atoms, (O) represents an oxygen atom or a single bond, and v represents an integer from 1 to 6. R ¹ is preferably straight-chain alkyl having 1 to 6 carbon atoms or straight-chain alkenyl having 2 to 6 carbon atoms, especially CH ₃ , C ₂ H ₅ , nC ₃ H ₇ , nC ₄ H ₉ , nC ₅ H ₁₁ , CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH- , CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

e) LC medium further comprising at least one compound selected from the group consisting of formulas G1 to G4:

In the above formula, alkyl represents C _1-6 -alkyl, L ^x represents H or F, _and X represents F, Cl, OCF ₃ , OCHF ₂ or OCH=CF ₂ . Particular preference is given to compounds of formula G1 where X represents F.

f) LC medium further comprising at least one compound selected from the group consisting of formulas Y1 to Y15:

In the above formula, R ⁵ is R ¹ has one of the meanings described above, alkyl represents C _1-6 -alkyl, d represents 0 or 1, and z _and m each independently represent an integer of 1 to 6. In these compounds R ⁵ is particularly preferably C _1-6 -alkyl or -alkoxy or C _2-6 -alkenyl, _and d _is preferably 1. The LC medium according to the invention preferably comprises at least one compound of the above-mentioned formula in an amount of at least 5% by weight.

g) LC medium further comprising at least one biphenyl compound selected from the group consisting of formulas B1 to B3:

In the above formula, alkyl and alkyl ^* each, independently of one another, represent a straight-chain alkyl radical having 1 to 6 carbon atoms, and alkenyl and alkenyl ^* each, independently of one another, represent a straight-chain alkyl radical having 2 to 6 carbon atoms. Represents an alkenyl radical. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

The proportion of biphenyls of formulas B1 to B3 in the LC mixture is preferably at least 3% by weight, especially at least 5% by weight.

Compounds of formula B2 are particularly preferred.

Compounds of formulas B1 to B3 are preferably selected from the group consisting of the following subformulas B1a to B2c:

In the above formula, alkyl ^* represents an alkyl radical having 1 to 6 carbon atoms. The medium according to the invention particularly preferably comprises one or more compounds of the formulas B1a and/or B2c:

h) LC medium further comprising at least one compound of formula O1 to O11:

In the above formula, R ¹ and R ² have the meanings described above and preferably each, independently of one another, represents straight-chain alkyl having 1 to 6 carbon atoms or straight-chain alkenyl having 2 to 6 carbon atoms.

A preferred medium comprises one or more compounds selected from the formulas O1, O3 and O4:

i) LC medium further comprising at least one compound of formula F1

In the above equation,

는

Is

를 나타내고,

represents,

R ⁹ represents H, CH ₃ , C ₂ H ₅ or nC ₃ H ₇ , (F) represents an optional fluorine substituent, q represents 1, 2 or 3, and R ⁷ has the meaning described for R ¹ has one of

Particularly preferred compounds of formula FI are selected from the group consisting of the following subformulas Fl1 to Fl8:

In the above formula, R ⁷ preferably represents straight-chain alkyl and R ⁹ represents CH ₃ , C ₂ H ₅ or nC ₃ H ₇ . Particularly preferred are compounds of formula FI1, FI2 and FI3.

k) LC medium further comprising at least one compound selected from the group consisting of formulas VK1 to VK4:

In the above formula, R ⁸ has one of the meanings described for R ¹ and alkyl represents a straight-chain alkyl radical having 1 to 6 carbon atoms.

l) LC medium further comprising at least one compound comprising tetrahydronaphthyl or naphthyl units, for example selected from the group consisting of formulas N1 to N10:

In the above equation,

R ¹⁰ and R ¹¹ are each, independently of each other, an alkyl having 1 to 12 carbon atoms (where one or two non-adjacent CH ₂ groups are also -O-, - in such a way that the O atoms are not directly connected to each other) CH=CH-, -CO-, -OCO- or -COO-), preferably represents alkyl or alkoxy having 1 to 6 carbon atoms, R ¹⁰ and R ¹¹ preferably have 1 to 6 carbon atoms represents straight-chain alkyl or alkoxy having 6 carbon atoms, or straight-chain alkenyl having 2 to 6 carbon atoms,

Z ¹ and Z ² are each, independently of each other, -C ₂ H ₄ -, -CH=CH-, -(CH ₂ ) ₄ -, -(CH ₂ ) ₃ O-, -O(CH ₂ ) ₃ - , -CH=CH-CH ₂ CH ₂ -, -CH ₂ CH ₂ CH=CH-, -CH ₂ O-, -OCH ₂ -, -CO-O-, -O-CO-, -C ₂ F ₄ -, -CF=CF-, -CF=CH-, -CH=CF-, -CH ₂ - or represents a single bond.

m) LC medium further comprising at least one difluorodibenzo chroman and/or chroman of the formulas BC to RC, preferably in an amount of 3 to 20% by weight, especially in an amount of 3 to 15% by weight:

In the above equation,

R ¹¹ and R ¹² each, independently of one another, have one of the meanings described for R ¹¹ ,

Ring M is trans-1,4-cyclohexylene or 1,4-phenylene,

Z ^m is -C ₂ H ₄ -, -CH ₂ O-, -OCH ₂ -, -CO-O- or -O-CO-,

c is 0, 1 or 2.

Particularly preferred compounds of the formulas BC, CR and RC are selected from the group consisting of the following subformulas BC1 to RC3:

In the above formula, alkyl and alkyl ^* each, independently of one another, represent a straight-chain alkyl radical having 1 to 6 carbon atoms, (O) is an oxygen atom or a single bond, c is 1 or 2, alkenyl and alkyl Kenyl ^* each independently represents a straight-chain alkenyl radical having 2 to 6 carbon atoms. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

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

n) LC medium further comprising at least one fluorinated phenanthrene and/or dibenzofuran of the formula PH or BF:

In the above formula, R ¹¹ and R ¹² each, independently of one another, have one of the meanings described above for R ¹¹ , b represents 0 or 1, L represents F, and r represents 1, 2 or 3. .

Particularly preferred compounds of formula PH and BF are selected from the group consisting of the following subformulas PH1 to BF1:

In the above formula, R and R' each independently represent a straight-chain alkyl or alkoxy radical having 1 to 7 carbon atoms.

o) LC medium further comprising at least one monocyclic compound of formula Y:

In the above equation,

R ¹ and R ² are each, independently of each other, an alkyl having 1 to 12 carbon atoms (where one or two non-adjacent CH ₂ groups are also -O-, - in such a way that the O atoms are not directly connected to each other) CH=CH-, -CO-, -OCO- or -COO-), preferably alkyl or alkoxy having 1 to 6 carbon atoms,

L ¹ and L ² each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F, and CHF ₂ .

Preferably, both L ¹ and L ² represent F or one of L ¹ and L ² represents F and the other represents Cl,

Compounds of formula Y are preferably selected from the group consisting of the following subformulas Y1 to Y10:

In the above formula, alkyl and alkyl ^* each, independently of one another, represent a straight-chain alkyl radical having 1 to 6 carbon atoms, alkoxy represents a straight-chain alkoxy radical having 1 to 6 carbon atoms, and alkenyl and alkenyl ^* represents, independently of each other, a straight-chain alkenyl radical having 2 to 6 carbon atoms, and O represents an oxygen atom or a single bond. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Particularly preferred compounds of formula Y are selected from the group consisting of the following subformulas Y6A and Y6B:

In the above formula, alkoxy preferably represents straight-chain alkoxy having 3, 4, or 5 carbon atoms.

p) LC medium further comprising at least one terphenyl compound selected from the group consisting of formula Q:

In the above equation,

R ^Q is alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 carbon atoms, or alkenyl or alkenyloxy having 2 to 9 carbon atoms, all of which are optionally fluorinated;

^and

L ^Q1 to L ^Q6 are, independently of each other, H or F, but at least one of L ^Q1 to L ^Q6 is F.

Preferred compounds of formula Q are those where R ^Q is a straight-chain alkyl having 2 to 6 carbon atoms, very preferably ethyl, n-propyl or n-butyl.

Preferred compounds of formula Q are those where L ^Q3 and L ^Q4 are F. Further preferred compounds of formula Q are those where L ^Q3 , L ^Q4 and one or both of L ^Q1 and L ^Q2 are F.

Preferred compounds of formula Q are those where X ^Q represents F or OCF ₃ , very preferably F.

Compounds of formula Q are preferably selected from the following subformulas Q1 or Q2:

In the above formula, R ^Q has the meaning of formula Q or one of its preferred meanings given above and below, and is preferably ethyl, n-propyl or n-butyl.

Particularly preferred are compounds of formula Q1, especially those where R ^Q is n-propyl.

Preferably, the proportion of compounds of formula Q in the LC medium is greater than 0 and up to 5% by weight, very preferably 0.1 to 2% by weight and most preferably 0.2 to 1.5% by weight.

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

The addition of a quarterphenyl compound of formula Q to the LC media mixture reduces ODF staining, maintains high UV absorption, enables fast and complete polymerization, enables strong and fast tilt angle generation, and reduces the UV absorption of the LC media. Increases stability.

Moreover, the addition of a compound of formula Q with positive dielectric anisotropy to the above LC medium with negative dielectric anisotropy results in the dielectric constant ε _|| and ε _⊥ , but especially for high values of the dielectric constant ε _|| The dielectric anisotropy Δε is maintained constant while achieving , thereby reducing kick-back voltage and afterimage.

q) LC medium free from polymerisable compounds according to the invention, in particular compounds of formula (I) or sub-formulas thereof and, apart from comonomers, compounds comprising terminal vinyloxy groups (-O-CH=CH ₂ ).

r) LC medium comprising 1 to 5, preferably 1, 2 or 3 polymerisable compounds, preferably selected from the polymerisable compounds according to the invention, especially compounds of formula (I) or subformulas thereof.

s) LC medium, wherein the proportion of polymerisable compounds, especially compounds of formula (I) or sub-formulas thereof, in the total mixture is 0.05 to 5%, preferably 0.1 to 1%.

t) LC medium comprising 1 to 8, preferably 1 to 5, compounds of the formula CY1, CY2, PY1 and/or PY2. The proportion of these compounds in the total mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The individual contents of these compounds are preferably 2 to 20% in each case.

u) LC medium comprising 1 to 8, preferably 1 to 5, compounds of the formula CY9, CY10, PY9 and/or PY10. The proportion of these compounds in the total mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The individual contents of these compounds are preferably 2 to 20% in each case.

v) LC medium comprising 1 to 10, preferably 1 to 8, compounds of formula ZK, especially compounds of formula ZK1, ZK2 and/or ZK6. The proportion of these compounds in the total mixture is preferably 3 to 25%, particularly preferably 5 to 45%. The individual contents of these compounds are preferably 2 to 20% in each case.

w) LC medium, wherein the proportion of compounds of the formulas CY, PY and ZK in the total mixture is greater than 70%, preferably greater than 80%.

x) a compound in which said LC host mixture contains an alkenyl group, preferably of the formulas CY, PY and LY, wherein one or both of R ¹ and R ² represents a straight chain alkenyl having 2 to 6 carbon atoms; , with the formulas ZK and DK, where one or both of R ³ and R ⁴ or one or both of R ⁵ and R ⁶ represents a straight chain alkenyl having 2 to 6 carbon atoms, and with formulas B2 and B3 LC medium comprising at least one compound selected from the group consisting of, very preferably at least one compound selected from the formulas 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%.

y) LC medium comprising at least one, preferably 1 to 5 compounds selected from the formulas PY1 to PY8, very preferably of the formula PY2. The proportion of these compounds in the total LC host mixture is preferably 1 to 30%, particularly preferably 2 to 20%. The individual contents of these compounds are preferably 1 to 20% in each case.

The combination of the compounds of the above-mentioned preferred embodiments with the above-described polymerized compounds provides the LC medium according to the invention with a low threshold voltage, low rotational viscosity and very good low-temperature stability, at the same time a consistently high clearing point and high HR values. and allows rapid establishment of particularly low pretilt angles for PSA displays. In particular, LC media exhibit very short response times in PSA displays compared to media from the prior art, and especially gray tint response times.

The LC medium and LC host mixture of 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 at most 250 mPa·s, preferably at most 200 mPa·s. has

In a VA-type display according to the invention, the molecules in the layer of the LC medium in the switched-off state are either oriented perpendicular to the electrode surface (homeotropic orientation) or have an inclined homeotropic orientation. Upon application of electrical voltage, rearrangement of LC molecules occurs with the longitudinal molecular axis parallel to the electrode surface.

The LC medium according to the invention, based on compounds with negative dielectric anisotropy, especially for use in displays of the PS-VA and PS-UB-FFS types, very preferably has a temperature range of -0.5 to -0.5 at 20° C. and 1 kHz. It has a negative dielectric anisotropy Δε of -10, especially -2.5 to -7.5.

The birefringence Δn in the LC media according to the invention used in displays of the PS-VA and PS-UB-FFS types is preferably less than 0.16, particularly preferably 0.06 to 0.14 and very particularly preferably 0.07 to 0.12.

The LC media according to the invention may also comprise further additives known to the person skilled in the art and described in the literature, such as polymerization initiators, inhibitors, stabilizers, surface-active components or chiral dopants. They may or may not be polymerizable. The polymerisable additive is therefore given as polymerisable component or component A). Non-polymerizable additives are therefore given as non-polymerizable components or component B).

In a preferred embodiment, the LC medium comprises one or more chiral dopants, preferably in a concentration of 0.01 to 1%, very preferably 0.05 to 0.5%. The chiral dopants are preferably from the group consisting of compounds from Table B below, very preferably R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011, and It is selected from the group consisting of R- or S-5011.

In another preferred embodiment, the LC medium comprises a racemate of at least one chiral dopant, preferably selected from the chiral dopants mentioned in the previous paragraph.

In addition, to the LC medium, for example 0 to 15% by weight of pleochroic dyes to improve conductivity, also nanoparticles, conductive salts, preferably ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutyl-ammonium tetraphenyl. complexing of borates or crown ethers (see, e.g., Haller et al., Mol. Cryst. Liq. Cryst. 24, 249-258 (1973)), or altering the dielectric anisotropy, viscosity, and/or orientation of the nematic phase. It is possible to add substances to change it. Materials of this type are described, for example, in DE-A 22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430 and 28 53 728.

Preferred embodiments a) to z) of the LC media according to the invention are known or can be easily derived from the prior art by a person skilled in the art, since the methods for their preparation are based on standard methods described in the literature. Corresponding compounds of formula CY are described for example in EP-A-0 364 538. The corresponding compounds of formula ZK are described for example in DE-A-26 36 684 and DE-A-33 21 373.

The LC media that can be used according to the invention are prepared in a manner customary per se, for example by mixing one or more of the above-mentioned compounds with one or more polymerisable compounds as defined above, and optionally further liquid crystalline compounds and/or additives. do. In general, the preferred amount of ingredient used in smaller amounts is Advantageously, it dissolves in the ingredients that make up the major constituents at elevated temperatures. It is also possible to mix a solution of the components in an organic solvent such as acetone, chloroform or methanol, mix thoroughly and then remove the solvent again, for example by distillation. The invention also relates to a process for preparing the LC medium according to the invention.

It will be appreciated by those skilled in the art that the LC medium according to the invention may also comprise compounds in which, for example, H, N, O, Cl, F are replaced by corresponding isotopes such as deuterium and the like.

The following examples illustrate the invention without limiting it. However, these examples show to those skilled in the art the preferred mixture concepts with the compounds preferably used, their respective concentrations and their combinations with each other. Additionally, the examples illustrate acceptable characteristics and combinations of characteristics.

The following abbreviations are used:

(n, m, z are in each case, independently of each other, 1, 2, 3, 4, 5 or 6)

Table A

In a preferred embodiment of the invention, the LC medium according to the invention comprises at least one compound selected from the group consisting of compounds from Table A.

Table B shows possible chiral dopants that can be added to the LC medium according to the invention.

Table B

The LC medium preferably comprises 0 to 10% by weight, especially 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight of chiral dopant. The LC medium preferably comprises one or more dopants selected from the group consisting of compounds from Table B below.

Table C shows possible stabilizers that can be added to the LC medium according to the invention.

Table C

(where n represents an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7 or 8, and the terminal methyl group is not shown)

The LC medium preferably comprises 0 to 10% by weight of stabilizers, especially 1 ppm to 5% by weight, particularly preferably 1 ppm to 1% by weight. The LC medium preferably comprises one or more stabilizers selected from the group consisting of compounds from Table C below.

Table D

Table D shows exemplary compounds that can be used in the LC medium according to the invention, preferably as reactive mesogenic compounds.

In a preferred embodiment of the invention, the mesogenic medium comprises at least one compound selected from the group of compounds selected from Table D. Very preferably, the LC medium is a compound selected from the formulas RM-1 to RM-32, most preferably RM-1, RM-15 or RM-17, or a compound of the formulas RM-41 to RM-48, most preferably includes compounds selected from the formula RM-41:

Additionally, the following abbreviations and symbols are used:

V ₀ represents the threshold voltage (capacitance) [V] at 20°C,

n _e is the anomalous refractive index measured at 20°C and 589 nm,

n _o is the normal refractive index measured at 20°C and 589 nm,

Δn is the optical anisotropy measured at 20°C and 589 nm;

ε _⊥ is the dielectric susceptibility perpendicular to the direction at 20°C and 1 kHZ,

ε _∥ is the dielectric susceptibility parallel to the director at 20°C and 1 kHZ,

Δε is the dielectric anisotropy at 20°C and 1 kHZ,

cl.p. or T(N,I) is the clearing point [℃],

γ ₁ is the rotational viscosity [mPa·s] measured at 20°C,

K ₁ is the elastic modulus (“splay” strain) [pN] at 20°C,

K ₂ is the elastic modulus (“twist” strain) [pN] at 20°C,

K ₃ is the elastic modulus (“bend” strain) [pN] at 20°C.

Unless explicitly stated otherwise, all concentrations in the present invention are quoted in weight percent and relate to the corresponding total mixture comprising all solid or liquid crystalline components without solvent.

Unless explicitly stated otherwise, all temperature values described herein, such as melting point T(C,N), transition temperature from smetic (S) to nematic (N) phase T(S,N), and clearing point. T(N,I) is quoted in degrees Celsius (°C). M.p. represents the melting point, and cl.p. represents the clearing point. Additionally, C = crystalline phase, N = nematic phase, S = smectic phase and I = isotropic phase. The numbers between these symbols represent the transition temperature.

All physical properties are described in “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, Status Nov. 1997, Merck KGaA, Germany], applying a temperature of 20°C, and in each case, unless otherwise stated, Δn is determined at 589 nm and Δε is determined at 1 kHz.

In the present invention, the term “threshold voltage”, unless explicitly stated otherwise, relates to the capacitive threshold voltage (V ₀ ), also known as the Fredericks threshold. In embodiments, the optical threshold voltage may also be quoted, typically at 10% relative contrast (V ₁₀ ).

Unless otherwise stated, the processes for polymerization of polymerizable compounds in PSA displays described above and below are carried out at a temperature where the LC medium exhibits a liquid crystalline phase, preferably a nematic phase, and most preferably at room temperature. do.

Unless otherwise stated, methods of fabricating test cells and measuring their electro-optical and other properties are performed similarly or by methods described hereinafter.

The display used for the measurement of the capacitive threshold voltage consists of two face-parallel glass outer plates with a gap of 25 μm having an electrode layer on the inside and a rubbed polyimide orientation layer on top, which are the homeocenters of the liquid crystal molecules. Affects tropic edge orientation.

The display or test cell in which the tilt angle is measured consists of two face-parallel glass outer plates spaced 4 μm apart with an electrode layer on the inside and a rubbed polyimide orientation layer on top, wherein the two polyimide The mid layers are rubbed against each other and affect the homeotropic edge orientation of the liquid crystal molecules.

The polymerisable compound is polymerized by irradiation of UVA light of determined intensity for a prespecified time in the display or test cell by means of a voltage simultaneously applied to the display (often 10 V to 30 V alternating current, 1 kHz). In the examples, unless otherwise stated, a metal halide lamp or a high pressure mercury lamp and an intensity of 50 mW/cm ² are used for polymerization. The intensity is measured using a standard UVA meter (Hoenle UV-meter high resolution with UVA sensor).

The tilt angle is determined by a crystal rotation experiment (Otronic-Meltzers TBA-105). Low values (i.e. large deviations from the 90° angle) correspond here to large inclinations.

VHR values were determined as follows: 0.3% of the polymerizable monomeric compound was added to the LC host mixture and the resulting mixture was introduced into a VA-VHR test cell containing an unrubbed VA-polyimide orientation layer. Unless otherwise stated, the LC-layer thickness d is approximately 6 μm. VHR values are measured before and after UV exposure at 1 V, 60 Hz, 64 μs pulses (Measuring instrument: Otronic-Meltzers VHRM-105).

Example One

The nematic LC host mixture N1 was formulated as follows.

Usage Example A

The polymerisable mixture is prepared by adding the reactive mesogen M1 to the nematic LC host mixture N1 at a concentration of 0.3% by weight and further adding a stabilizer of formula S1a or S1b, or a prior art stabilizer SC in various concentrations. Manufactured.

The composition of the polymerizable mixture is shown in Table 1 below.

Table 1 - polymerizability mixture composition

The VHR value of the polymerizable mixture is measured before and after UV exposure for 80 minutes at 20° C. or 60° C., respectively, using a fluorescent UV lamp type C (305 nm to 355 nm).

The VHR values of the polymer mixtures are shown in Table 1 below.

Table 2 - VHR value

From Table 2, it can be seen that the compounds P1 to P6 according to the invention containing a stabilizer of formula S1a or S1b show significantly higher VHR values after UV exposure, comparable to the mixture CP1 containing only the stabilizer SC. You can check that.

Each of the polymerizable mixture according to the present invention and the polymerizable comparative mixture are respectively injected into the VA e/o test cell. The test cell contained an antiparallel rubbed VA-polyimide orientation layer (JALS-2096-R1). The LC-layer thickness d is approximately 4 μm.

To determine the polymerization rate, polymerization in the test cell using a fluorescent UV lamp type C (305 nm to 355 nm) at 60°C for 80 minutes was followed by HPLC to determine the residual content (% by weight) of unpolymerized RM in the test cell. ) is measured. For this purpose, the polymerized mixture is then rinsed from the test cell using MEK (methyl ethyl ketone) and measured.

The remaining concentration of RM in the mixture after 80 minutes of irradiation is shown in Table 3 below.

Table 3 - Residual monomer content

From Table 3, it can be seen that mixtures P1 to P6 according to the invention with stabilizers of formula S1a or S1b show rapid polymerization with a low amount of residual RM, comparable to mixture CP1 without stabilizers of formula S1a or S1b. You can check it.

By crystal rotation experiments (Autronic-Melchers TBA-105). After UV irradiation of 50 mW/cm ² for 120 seconds (6 J), the pretilt angle is measured.

The pretilt angles are shown in Table 4 below.

Table 4 - pretilt angle

From Table 4, it can be seen that mixtures P1 to P6 according to the invention containing stabilizers of formula S1a or S1b show a pretilt angle generation comparable to mixture CP1 without stabilizers of formula S1a or S1b.

The results show that the polymerizable mixture according to the invention comprising a stabilizer of formula S shows improved reliability with higher VHR values after UV exposure compared to polymerizable mixtures with stabilizers known from the prior art. It also shows that other properties such as pretilt angle generation and rapid and complete polymerization are not negatively affected by the addition of the stabilizer of formula S.

Usage Example B

Comparative polymerizable mixture CP2 was prepared by adding 0.3% by weight of reactive mesogen M1 to the nematic LC host mixture N1.

Polymerizable mixture P7 according to the invention is prepared by adding 0.3% by weight of reactive mesogen M1 and 100 ppm of stabilizer of formula S2a to the nematic LC host mixture N1.

The VHR values of the polymerizable mixtures are measured before and after UV exposure at 20° C. or 60° C., respectively, for 80 minutes using a fluorescent UV lamp type C (305 nm to 355 nm).

The VHR values of the polymerizable mixture are shown in Table 5 below.

Table 5 - VHR value

From Table 5, it can be seen that the mixture P7 according to the invention containing the stabilizer of formula S2a shows a higher VHR value after UV exposure compared to the mixture CP2 without the stabilizer.

The polymerizable mixture according to the invention and the comparative polymerizable mixture are each inserted into the VA e/o test cell. The test cell contained an antiparallel rubbed VA-polyimide orientation layer (JALS-2096-R1). The LC-layer thickness d is approximately 4 μm.

To determine the polymerization rate, polymerization in the test cell using a fluorescent UV lamp type C (305 nm to 355 nm) at 60°C for 80 minutes followed by residual content (% by weight) of unpolymerized RM in the test cell by HPLC. Measure. The polymerized mixture is then rinsed from the test cell using MEK (methyl ethyl ketone) and measured.

The remaining concentration of RM in the mixture after 80 minutes of irradiation is shown in Table 6 below.

Table 6 - Residual monomer content

From Table 6, it can be seen that mixture P7 according to the invention containing a stabilizer of formula S2a shows rapid polymerization with a low amount of residual RM comparable to mixture CP2 without stabilizer.

The pretilt angle is measured before and after UV irradiation using a high-pressure Hg lamp (20J) at 50 mW/cm ² for 400 seconds by a crystal rotation experiment (Otronic-Meltzers TBA-105).

The pretilt angles are shown in Table 7 below.

Table 7 - pretilt angle

From Table 7, it can be seen that mixture P7 according to the present invention containing the stabilizer of formula S2a shows a pretilt angle generation comparable to that of mixture CP2.

The above results show that the polymerizable mixture according to the present invention containing the stabilizer of formula S shows improved reliability with a high VHR value after UV exposure, while other factors such as generation of pretilt angle and rapid and complete polymerization due to the addition of the stabilizer. It shows that the trait is not negatively affected.

Claims (20)

- a polymerizable component A) comprising at least one polymerizable compound, and
- Liquid crystal component B) comprising at least one mesogenic or liquid crystal compound comprising at least one compound of the formula A, at least one compound of the formula B and at least one compound of the formula T:

[In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:
R ¹ and R ² represent alkyl or alkoxy having 1 to 9 carbon atoms, or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 9 carbon atoms, all of which are optionally fluorinated;
L ¹ and L ² represent F or Cl,
L ^T1 to L ^T6 represent H, F or Cl, and at least one of L ^T1 to L ^T6 is F or Cl]
A liquid crystal (LC) medium comprising one or more compounds selected from the formula S:

[In the above equation,
R ^a , R ^b , R ^c and R ^d independently of one another represent straight-chain or branched-chain alkyl having 1 to 10 carbon atoms,
X represents H, CH ₃ , OH or O ^ㆍ ,
A represents a straight-chain, branched or cyclic alkylene having 1 to 20 carbon atoms, which is optionally substituted. According to claim 1,
LC medium, wherein the compounds of formula S are selected from the following subformulas S1 to S5:

[In the above equation,
X represents H, CH ₃ , OH or O ^ㆍ ,
R ^A represents methyl, ethyl, propyl, butyl, pentyl or hexyl,
n1 is an integer from 2 to 12,
n2 is 0 or an integer from 1 to 12,
n3 is 0 or an integer from 1 to 12, where
In the formulas S1 to S4, one or more H-atoms in the radical (CH ₂ ) _n1 are optionally replaced by a methyl, ethyl, propyl, butyl, pentyl or hexyl group]. According to claim 1,
LC medium, wherein the compounds of formula S are selected from the following subformulas S1a, S1b, S2a to S2c, S3a and S4a:

. According to claim 1,
LC medium, wherein the compound of formula A is selected from subformula A1:

[In the above formula, alkyl represents a straight-chain alkyl radical having 1 to 6 carbon atoms, and (O) represents an oxygen atom or a single bond]. According to claim 1,
LC medium, wherein the compound of formula B is selected from formula B1:

[In the above formula, alkyl represents a straight-chain alkyl radical having 1 to 6 carbon atoms, and (O) represents an oxygen atom or a single bond]. According to claim 1,
LC medium, wherein the compound of formula T is selected from the group consisting of formulas T1 to T24:

[In the above formula, R represents a straight-chain alkyl or alkoxy radical having 1 to 7 carbon atoms, R ^* represents a straight-chain alkenyl having 2 to 7 carbon atoms, (O) represents an oxygen atom or a single bond, , m represents an integer from 1 to 6]. According to claim 1,
LC medium, wherein the polymerisable compound is selected from the formula (I):

[In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:
R ^a and R ^b are P, P-Sp-, H, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, SF ₅ or 1 to 25 represents a straight-chain or branched alkyl with a carbon atom, wherein one or more non-adjacent CH ₂ groups are also, independently of each other, in such a way that the O and/or S atoms are not directly connected to each other -C(R ⁰ )=C( R ⁰⁰ )-, -C≡C-, -N(R ⁰⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be replaced with, wherein one or more H atoms may also be replaced with F, Cl, Br, I, CN, P or P-Sp-, and B ¹ and/or B ² contain a saturated carbon atom. In this case, R ^a and/or R ^b may also represent a radical spiro-linked to the saturated carbon atom,
wherein at least one of the radicals R ^a and R ^b represents or contains the group P or P-Sp,
P is a polymerizable group,
Sp is a spacer group or single bond,
B ¹ and B ² represent an aromatic, heteroaromatic, cycloaliphatic or heterocyclic group having 4 to 25 ring atoms, which may contain fused rings and are unsubstituted or mono- or polysubstituted with L,
Z ^b is -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 represents a single bond ,
R ⁰ and R ⁰⁰ represent H or alkyl having 1 to 12 carbon atoms,
m represents 0, 1, 2, 3 or 4,
n1 represents 1, 2, 3 or 4,
L is 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 carbon atoms. , or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxy-carbonyloxy having 1 to 25 carbon atoms, wherein one or more H atoms are also F, may be replaced by Cl, P or P-Sp-,
Y ¹ represents halogen,
^R _{_} may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and one or more H atoms may also be replaced by , Cl, P or P-Sp-), an optionally substituted aryl or aryloxy group having 6 to 40 carbon atoms, or an optionally substituted hetero-aryl having 2 to 40 carbon atoms. or hetero-aryloxy group]. According to claim 7,
B ¹ and B ² are each independently selected from 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 (wherein these groups one or more CH groups may also be replaced by N), cyclohexane-1,4-diyl, where one or more non-adjacent CH ₂ groups may also be replaced by O and/or S, 1,4 -Cyclohexenylene, bicycle-[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, decahydro-naphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indan-2,5 -diyl or octahydro-4,7-methanoindan-2,5-diyl (wherein all these groups may be unsubstituted or mono- or polysubstituted with L as defined in claim 7) LC medium selected from. According to claim 1,
LC medium, wherein the polymerisable compound is selected from the formulas M1 to M30:

[In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:
P ¹ , P ² and P ³ represent vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane or epoxy group,
Sp ¹ , Sp ² and Sp ³ represent a single bond or spacer group, where one or more of the radicals P ¹ -Sp ¹ -, P ¹ -Sp ² - and P ³ -Sp ³ - can also represent R ^aa . provided that at least one of the radicals P ¹ -Sp ¹ -, P ² -Sp ² and P ³ -Sp ³ - present is different from R ^aa ,
R ^aa is H, F, Cl, CN or a straight-chain or branched alkyl having 1 to 25 carbon atoms, wherein one or more non-adjacent CH ₂ groups are also, each independently of one another, O and/or S atoms directly adjacent to each other. In a non-connected manner, -C(R ⁰ )=C(R ^{0 0} )-, -C≡C-, -N(R ⁰ )-, -O-, -S-, -CO-, -CO-O -, -O-CO-, -O-CO-O-, where one or more H atoms can also be replaced by F, Cl, CN or P ¹ -Sp ¹ -) ,
R ⁰ and R ⁰⁰ represent H or alkyl having 1 to 12 carbon atoms,
R ^y and R ^z represent H, F, CH ₃ or CF ₃ ,
X ¹ , X ² and X ³ represent -CO-O-, -O-CO- or a single bond,
Z ¹ represents -O-, -CO-, -C(R ^y R ^z )- or -CF ₂ CF ₂ -,
Z ² and Z ³ represent -CO-O-, -O-CO-, -CH ₂ O-, -OCH ₂ -, -CF ₂ O-, -OCF ₂ - or -(CH ₂ ) _n -, In this case, n is 2, 3, or 4,
L is F, Cl, CN or straight or branched alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkyl having 1 to 12 carbon atoms, optionally mono- or polyfluorinated. Represents carbonyloxy or alkoxycarbonyloxy,
L' and L" represent H, F or Cl,
r represents 0, 1, 2, 3 or 4,
s represents 0, 1, 2 or 3,
t represents 0, 1 or 2,
x represents 0 or 1]. According to clause 9,
LC medium, wherein the polymerisable compound is selected from the formulas M2 and M13:

According to claim 1,
LC medium comprising one or more compounds selected from the formulas AN and AY:

[In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:

Is

or

represents,

Is

or

represents,

Is

or

represents,
R ^A1 represents alkenyl having 2 to 9 carbon atoms, or when at least one of rings X, Y and Z represents cyclohexenyl, it also represents one of the meanings of R ^A2 ,
R ^A2 represents alkyl having 1 to 12 carbon atoms, where one or two non-adjacent CH ₂ groups are also -O-, -CH=CH-, - may be replaced by CO-, -OCO- or -COO-,
Z ^x is -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 , L ² , L ³ and L ⁴ represent H, F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ H,
x represents 1 or 2,
z represents 0 or 1]. According to claim 1,
LC medium comprising one or more compounds selected from the formulas CY and PY:

[In the above formula, individual radicals have the following meanings:
a represents 1 or 2,
b represents 0 or 1,

Is

or

represents,
R ¹ and R ² each, independently of one another, represent an alkyl having 1 to 12 carbon atoms, where one or two non-adjacent CH ₂ groups are also -O- in such a way that the O atoms are not directly connected to each other. , -CH=CH-, -CO-, -O-CO- or -CO-O-,
Z ^x is -CH=CH-, -CH ₂ O-, -OCH ₂ -, -CF ₂ O-, -OCF ₂ -, -O-, -CH ₂ -, -CH ₂ CH ₂ - or a single bond represents,
L ¹ , L ² , L ³ and L ⁴ each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ ]. According to claim 1,
LC medium comprising one or more compounds selected from the formulas ZK and DK:

[In the above formula, the individual radicals have the following meanings independently of each other in each case, either identically or differently:

Is

or

represents,

Is

or

represents,

Is

or

represents,
R ³ and R ⁴ each, independently of one another, represent alkyl having 1 to 12 carbon atoms, where one or two non-adjacent CH ₂ groups are also -O- in such a way that the O atoms are not directly connected to each other. , -CH=CH-, -CO-, -O-CO- or -CO-O-,
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 -, -CF=CF- or represents a single bond,
R ⁵ and R ⁶ are each, independently of each other, an alkyl having 1 to 12 carbon atoms (where one or two non-adjacent CH ₂ groups are also -O-, - CH=CH-, -CO-, -OCO- or -COO-),
e represents 1 or 2]. The method according to any one of claims 1 to 13,
LC medium in which the polymerizable compound is polymerized. 14. An LC display comprising an LC medium as defined in any one of claims 1 to 13. According to claim 15,
PSA type display, LC display. According to claim 16,
LC displays, which are PS-VA, PS-IPS or PS-UB-FFS displays. According to claim 16,
Two substrates, at least one of which is optically transparent, an electrode provided on each substrate or two electrodes provided on only one of the two substrates, and a layer of the LC medium positioned between the substrates, wherein a polymeric LC display, comprising a compound polymerized between the substrates of the display. A method of manufacturing an LC display according to claim 18, comprising providing an LC medium between the substrates of the display and polymerizing a polymerisable compound. At least one compound of formula A as defined in claim 1 or 4, at least one compound of formula B as defined in claim 1 or 5 and at least one compound of formula T as defined in claim 1 or 6. , one or more compounds of formula S as defined in claims 1, 2 or 3, and one or more polymerisable compounds as defined in any one of claims 1 and 7 to 10, and optionally A process for preparing an LC medium according to any one of claims 1 to 11, comprising the step of mixing with further LC compounds and/or additives.