Patent Application
20250207031
This application filed under 35 U.S.C. § 111 (a) claims priority benefit under 35 U.S.C. § 119 (a) of and to EP patent application Ser. No. 23/218,969.6, filed Dec. 21, 2023, the entire contents of which are incorporated herein by reference in their entirety and for all purposes.
The present invention relates to an LC medium (as a subcategory of liquid crystal material) comprising two or more polymerizable compounds, to its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in LC displays of the PSA (polymer sustained alignment) or SA (self-aligning) mode, to an LC display of the PSA or SA mode comprising the LC medium, and to a process of manufacturing the LC display using the LC medium, especially an energy-saving LC display and energy-saving LC display production process.
The popularity of 8K and gaming monitors leads to an increased need for LC display (LCD) panels having higher refresh rates and thus for LC media having faster response times. Many of these LCD panels are using polymer stabilized (PS) or polymer sustained alignment modes (PSA) modes, like the PS-VA (vertically aligned), PS-IPS (in-plane switching) or PS-FFS (fringe-field switching) mode or modes derived therefrom, or self-aligned (SA) modes like SA-VA which are polymer stabilized.
In the PS or PSA mode a small amount, typically from 0.1 to 1% of one or more polymerizable mesogenic compounds, also known as RMs (reactive mesogens), is added to the LC medium. After filling the LC medium into the display, the RMs are then polymerized in situ by UV photopolymerization, while a voltage is applied to the electrodes of the display. Thereby a small tilt angle is generated in the LC molecules of the LC medium, which is stabilized by the polymerized RMs. The UV polymerization process, also referred to as “PSA process”, is usually carried out in two steps, a first UV exposure step (“UV1 step”), with application of a voltage, to generate the tilt angle, and a second UV exposure step (“UV2 step”), without application of a voltage, to complete polymerization of the RMs.
In the SA-VA mode the alignment layers are omitted in the display. Instead, a small amount, typically 0.1 to 2.5%, of a self-alignment (SA) additive is added to the LC medium, which induces the desired alignment, for example homeotropic or planar alignment, in situ by a self-assembling mechanism. The SA additive usually contains an organic, mesogenic core group and attached thereto one or more polar anchor groups, for example hydroxy, carboxy, amino or thiol groups, which can interact with the substrate surface, causing the additives on the substrate surface to align and induce the desired alignment also in the LC molecules. The SA additive may also contain one or more polymerizable groups that can be polymerized under similar conditions as the RMs used in the PSA process. The LC medium may in addition to the SA additive also contain one or more RMs.
One method to reduce the response times in LC media for the PSA mode is for example by using compounds with an alkenyl group as components of the LC host mixture. However, this may lead to a decrease of the reliability of the mixture when being exposed to the UV light need to polymerize the RMs additives, which is believed to be caused by a reaction of the alkenyl compound with the polyimide of the alignment layer, which is especially problematic when using shorter UV wavelengths of less than 320 nm. Therefore, there is a tendency to use longer UV wavelengths for the PSA process.
UV-LED lamps have also been proposed for use in the PSA process, as they show less energy consumption, longer lifetime, and more effective optical energy transfer to the LC medium due to the narrower emission peak, which allows to reduce the UV intensity and/or UV irradiation time. This enables a reduced tact time and savings in energy and production costs. The UV lamps currently available have higher wavelength emission, for example at 365 nm.
Therefore, there is also need for polymerizable LC media which enables the RMs to be effectively polymerized at longer UV wavelengths.
A further problem in the production of PSA displays is the presence or removal of residual amounts of unpolymerized RMs, in particular after the polymerization step for production of the tilt angle in the display. For example, unreacted RMs of this type may adversely affect the properties of the display by, for example, polymerizing in an uncontrolled manner during operation after finishing of the display.
Thus, in PSA displays of prior art often additional image sticking can be observed which is caused by the presence of unpolymerized RMs. Uncontrolled polymerization of the residual RMs is initiated here by UV light from the environment or by the backlighting. In the switched display areas, this changes the tilt angle after a number of addressing cycles. As a result, a change in transmission in the switched areas may occur, while it remains unchanged in the unswitched areas.
It is therefore desirable for the polymerization of the RMs to proceed as completely as possible during production of the PSA display and for the presence of unpolymerized RMs in the display to be excluded as far as possible or reduced to a minimum. Thus, RMs and LC mixtures are required which enable or support highly effective and complete polymerization of the RMs. In addition, controlled reaction of the residual RM amounts would be desirable. This would be simpler if the RM polymerized more rapidly and effectively than the compounds known to date.
A further problem that has been observed in the operation of PSA displays is the stability of the tilt angle. Thus, it was observed that the tilt angle, which was generated during display manufacture by polymerizing the RM as described above, does not remain constant but can deteriorate after the display was subjected to voltage stress during its operation. This can negatively affect the display performance, e.g., by increasing the black state transmission, hence lowering the contrast.
It is therefore an object of the present invention to provide improved LC media comprising RMs for use in PSA or SA displays, and PSA or SA displays comprising them, which show very high specific resistance values, high VHR values, high reliability, low threshold voltages, short response times, high birefringence, good UV absorption especially at longer UV wavelengths, preferably in the range from 340 to 380 nm, quick and complete polymerization of the RMs, controlled generation of a low tilt angle, high tilt angle stability after UV exposure, reduced image sticking and ODF mura, and wherein the RMs show a high solubility in the LC host mixture.
It was found that one or more of these objects could be achieved by providing LC media which comprise two or more polymerizable compounds as disclosed and claimed hereinafter.
The invention relates to an LC medium having negative dielectric anisotropy and comprising one or more compounds selected from formulae L1 and L2, and further comprising two or more polymerizable compounds, preferably of formula M:
The invention further relates to an LC medium as described above and below, which additionally comprises one or more additives selected from the group consisting of stabilisers, chiral dopants, polymerization initiators and self-alignment additives.
The invention further relates to the use of the LC medium as described above and below in LC displays of the PSA or SA mode.
The invention furthermore relates to a process for preparing an LC medium as described above and below, comprising the steps of mixing one or more polymerizable compounds of formula M with one or more compounds of formula L1 and/or L2 and optionally with further LC compounds and/or additives.
The invention furthermore relates to an LC display comprising an LC medium according to the invention as described above and below, which is a PSA or SA display, preferably a PS-VA, PS-IPS, PS-FFS, PS-UB-FFS or SA-VA display.
The invention furthermore relates to an LC display comprising an LC medium as described above and below wherein the polymerizable compounds are present in ed form, which is preferably a PSA or SA display, very preferably a PS-VA, PS-IPS, PS-FFS, PS-UB-FFS or SA-VA display.
The invention furthermore relates to an LC display of the PSA type comprising two substrates, at least one which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and located between the substrates a layer of an LC medium as described above and below, wherein the polymerizable compounds are polymerized between the substrates of the display by UV photopolymerization.
The invention furthermore relates to a process for manufacturing an LC display as described above and below, comprising the steps of filling or otherwise providing an LC medium as described above and below between the substrates of the display, and polymerizing the polymerizable compounds, preferably by irradiation with UV light, preferably having a wavelength >340 nm, preferably >360 nm, preferably in the range from 340 to 400 nm, more preferably in the range from 350 to 390 nm, very preferably in the range from 360 to 380 nm, most preferably in the range from 360 to 368 nm, and preferably while a voltage is applied to the electrodes of the display.
The invention furthermore relates to a process for manufacturing an LC display as described above and below, wherein irradiation of the polymerizable compounds is carried out using a UV-LED lamp.
The LC media according to the present invention show the following advantageous properties when used in PSA displays:
In addition the LC media according to the present invention show one or more of the following advantageous properties:
An alkenyl group in the compounds of formula II or other components of the LC medium as disclosed below is not considered to be within the meaning of the term “polymerizable group” as used herein. The conditions for the polymerization of the polymerizable compounds of the LC medium are preferably selected such that alkenyl substituents do not participate in the polymerization reaction. Preferably the LC media disclosed and claimed in the present application do not contain an additive that initiates or enhances the participation of the alkenyl group in a polymerization reaction.
Unless stated otherwise, the polymerizable compounds and the compounds of formula II are preferably selected from achiral compounds.
As used herein, the expression “UV light having a wavelength of” followed by a given range of wavelengths (in nm), or by a given lower or upper wavelength limit (in nm), means that the UV emission spectrum of the respective radiation source has an emission peak, which is preferably the highest peak in the respective spectrum, in the given wavelength range or above the given lower wavelength limit or below the given upper wavelength limit and/or that the UV absorption spectrum of the respective chemical compound has a long or short wavelength tail that extends into the given wavelength range or above the given lower wavelength limit or below the given upper wavelength limit.
As used herein, the term “full width half maximum” or “FWHM” means the width of a spectrum curve measured between those points on the y-axis which are half the maximum amplitude.
As used herein, the term “substantially transmissive” means that the filter transmits a substantial part, preferably at least 50% of the intensity, of incident light of the desired wavelength(s). As used herein, the term “substantially blocking” means that the filter does not transmit a substantial part, preferably at least 50% of the intensity, of incident light of the undesired wavelengths. As used herein, the term “desired (undesired) wavelength” e.g. in case of a band pass filter means the wavelengths inside (outside) the given range of 2, and in case of a cut-off filter means the wavelengths above (below) the given value of 2.
As used herein, the terms “active layer” and “switchable layer” mean a layer in an electrooptical display, for example an LC display, that comprises one or more molecules having structural and optical anisotropy, like for example LC molecules, which change their orientation upon an external stimulus like an electric or magnetic field, resulting in a change of the transmission of the layer for polarized or unpolarized light.
As used herein, the terms “tilt” and “tilt angle” will be understood to mean a tilted alignment of the LC molecules of an LC medium relative to the surfaces of the cell in an LC display (here preferably a PSA display), and will be understood to be inclusive of “pretilt” and “pretilt angle”. The tilt angle here denotes the average angle (<)90° between the longitudinal molecular axes of the LC molecules (LC director) and the surface of the plane-parallel outer plates which form the LC cell. A low absolute value for the tilt angle (i.e. a large deviation from the 90° angle) corresponds to a large tilt here. A suitable method for measurement of the tilt angle is given in the examples. Unless indicated otherwise, tilt angle values disclosed above and below relate to this measurement method.
As used herein, the terms “reactive mesogen” and “RM” will be understood to mean a compound containing a mesogenic or liquid crystalline skeleton, and one or more functional groups attached thereto which are suitable for polymerization and are also referred to as “polymerizable group” or “P”.
Unless stated otherwise, the term “polymerizable compound” as used herein will be understood to mean a polymerizable monomeric compound.
An SA-VA display according to the present invention will be of the polymer stabilised mode as it contains, or is manufactured by use of, an LC medium containing RMs of formula I and II. Consequently as used herein, the term “SA-VA display” when referring to a display according to the present invention will be understood to refer to a polymer stabilised SA-VA display even if not explicitly mentioned.
As used herein, the term “low-molecular-weight compound” will be understood to mean to a compound that is monomeric and/or is not prepared by a polymerization reaction, as opposed to a “polymeric compound” or a “polymer”.
As used herein, the term “unpolymerizable compound” will be understood to mean a compound that does not contain a functional group that is suitable for polymerization under the conditions usually applied for the polymerization of the RMs.
The term “mesogenic group” as used herein is known to the person skilled in the art and described in the literature, and means a group which, due to the anisotropy of its attracting and repelling interactions, essentially contributes to causing a liquid-crystal (LC) phase in low-molecular-weight or polymeric substances. Compounds containing mesogenic groups (mesogenic compounds) do not necessarily have to have an LC phase themselves. It is also possible for mesogenic compounds to exhibit LC phase behaviour only after mixing with other compounds and/or after polymerization. Typical mesogenic groups are, for example, rigid rod- or disc-shaped units. An overview of the terms and definitions used in connection with mesogenic or LC compounds is given in Pure Appl. Chem. 2001, 73 (5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368.
The term “spacer group”, hereinafter also referred to as “Sp”, as used herein is known to the person skilled in the art and is described in the literature, see, for example, Pure Appl. Chem. 2001, 73 (5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368. As used herein, the terms “spacer group” or “spacer” mean a flexible group, for example an alkylene group, which connects the mesogenic group and the polymerizable group(s) in a polymerizable mesogenic compound.
Above and below,
denotes a trans−1,4-cyclohexylene ring, and
denotes a 1,4-phenylene ring.
In a group
the single bond shown between the two ring atoms can be attached to any free position of the benzene ring.
If in the formulae shown above and below a terminal group like R1A, 2A, R1, R2, R11,12,13, R21,22, R31, 32, R41,42, R51,52, R61,62, R71,72, R81,82,83, RO, R0, R, RM, RS, RS1,S2,S3,S4 or L denotes an alkyl radical and/or an alkoxy radical, this may be straight-chain or branched. It is preferably straight-chain, has 2, 3, 4, 5, 6 or 7 C atoms and accordingly preferably denotes ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexyloxy or heptyloxy, furthermore methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.
If one of the aforementioned terminal groups denotes an alkyl radical wherein one or more CH2 groups are replaced by S, this may be straight-chain or branched. It is preferably straight-chain, has 1, 2, 3, 4, 5, 6 or 7 C atoms and accordingly preferably denotes thiomethyl, thioethyl, thiopropyl, thiobutyl, thiopentyl, thiohexyl or thioheptyl.
Oxaalkyl preferably denotes straight-chain 2-oxapropyl (=methoxymethyl), 2-(=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3—, 4- or 5-oxahexyl, 2-, 3—, 4-, 5- or 6-oxaheptyl, 2-, 3—, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3—, 4-, 5-, 6-, 7- or 8-oxanonyl, 2-, 3—, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.
If one of the aforementioned terminal groups denotes an alkoxy or oxaalkyl group it may also contain one or more additional oxygen atoms, provided that oxygen atoms are not linked directly to one another.
If one of the aforementioned terminal groups denotes an alkyl radical in which one CH2 group has been replaced by —CH═CH—, this may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. Accordingly, it denotes, in particular, vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, hept-1-, -2-, -3-, -4-, -5- or -6-enyl, oct-1-, -2-, -3-, -4-, -5-, -6- or -7-enyl, non-1-, -2-, -3-, -4-, -5-, -6-, -7- or -8-enyl, dec-1-, -2-, -3-, -4-, -5-, -6-, -7-, -8- or -9-enyl.
If one of the aforementioned terminal groups denotes an alkyl or alkenyl radical which is at least monosubstituted by halogen, this radical is preferably straight-chain, and halogen is preferably F or CI. In the case of polysubstitution, halogen is preferably F. The resultant radicals also include perfluorinated radicals. In the case of monosubstitution, the fluorine or chlorine substituent may be in any desired position, but is preferably in the ω-position.
In another preferred embodiment, one or more of the aforementioned terminal groups, like R1A,2A, R1, R2, R11,12,13, R31, 32, R41,42, R51,52, R61,62, R71,72, R81,82,83, RO, R0, R, RM, RS, RS1,S2,S3,S4 or L are selected from the group consisting of
—OCH2OCH3, —O(CH2)3OCH3, —O(CH2)4OCH3, —O(CH2)2F, —O(CH2)3F, —O(CH2)4F.
Halogen is preferably F or Cl, very preferably F.
The group —CR0═CR00— is preferably —CH═CH—.
—CO—, —C(═O)— and —C(O)-denote a carbonyl group, i.e.
Preferred substituents L, are, for example, F, Cl, Br, I, —CN, —NO2, —NCO, —NCS, —OCN, —SCN, —C(═O) N(Rx)2, —C(═O)Y1, —C(═O)Rx, —N(Rx)2, straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 25 C atoms, in which one or more H atoms may optionally be replaced by F or Cl, optionally substituted silyl having 1 to 20 Si atoms, or optionally substituted aryl having 6 to 25, preferably 6 to 15, C atoms,
Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, furthermore phenyl.
is preferably
in which L has one of the meanings indicated above.
In the compounds of formula L1 and its subformulae, RL1 preferably denotes alkyl with 1, 2, 3, 4, 5 or 6 C atoms in which a CH2 group is optionally replaced by cyclopropane-1,2-diyl or cyclopentane-1,2-diyl, very preferably propyl, pentyl, cyclopropyl, cyclopentyl, cyclopropylmethyl or cyclopentylmethyl, most preferably propyl or pentyl.
In the compounds of formula L1 and its subformulae, XL preferably denotes F or CF3, very preferably CF3.
In the compounds of formula L1 and its subformulae, YL preferably denotes H or F, very preferably H.
In the compounds of formula L1, Y preferably denotes H or CH3, very preferably H.
Preferred compounds of formula L1 are selected from the following subformulae:
wherein RL1 has the meanings given in formula L1 above and preferably denotes alkyl having 1 to 6 C atoms in which a CH2 group is optionally replaced by cyclopropane-1,2-diyl or cyclopentane-1,2-diyl, very preferably propyl, pentyl, cyclopropyl, cyclopentyl, cyclopropylmethyl or cyclopentylmethyl, most preferably propyl or pentyl.
Very preferred are compounds of formula L1-2, especially wherein RL1 is n-propyl or n-pentyl.
In the compounds of formula L2 and its subformulae, RL1 preferably denotes alkyl with 1, 2, 3, 4, 5 or 6 C atoms, very preferably methyl.
In the compounds of formula L2 and its subformulae, RL2 preferably is selected from CH2═CH—, CH2═CHCH2—, CH2═CHCH2CH2—, CH3—CH—CH—, CH3—CH2—CH═CH—, CH3—(CH2)2—CH═CH—, CH3—(CH2)3—CH═CH— and CH3—CH═CH—(CH2)2—, more preferably from CH2═CH—, CH2═CHCH2— and CH3—CH═CH—, very preferably from CH2═CH—.
In the compounds of formula L2 and its subformulae, YL preferably denotes H or F, very preferably H.
In the compounds of formula L2, Y preferably denotes H or CH3, very preferably H.
Preferred compounds of formula L2 are selected from the following subformulae:
wherein “alkyl” means a straight-chain alkyl groups having 1 to 6 C atoms, in which a CH2 group may be replaced by cyclopropane-1,2-diyl or cyclopentane-1,2-diyl, and preferably denotes methyl, ethyl or propyl.
Very preferred are compounds of formula L2-1, especially wherein RL1 is methyl.
Preferably the total proportion of the compounds of formula L1 or its subformulae in the LC medium is from 0.1 to 10%, very preferably from 0.2 to 5%, most preferably from 0.3 to 3% by weight.
Preferably the total proportion of the compounds of formula L2 or its subformulae in the LC medium is from 0.1 to 10%, very preferably from 0.2 to 5%, most preferably from 0.3 to 3% by weight.
Further preferred embodiments of the LC medium according to the present invention are listed below, including any combination thereof:
Preferably the LC medium further comprises one or more compounds of formula II,
wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings:
in such a manner that O— and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl, CN or CF3, preferably alkyl or alkoxy having 1 to 6 C atoms,
Preferably the LC medium comprises one or more compounds of formula II selected from the group consisting of compounds of the formulae IIA, IIB, IIC and IID,
in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning:
in such a way that O— and/or S-atoms are not linked directly to one another,
Preferred compounds of the formulae IIA, IIB, IIC and IID are those wherein R22 denotes an alkyl or alkoxy radical having up to 15 C atoms, and very preferably denotes (O)CvH2v+1 wherein (O) is an oxygen atom or a single bond and v is 1, 2, 3, 4, 5 or 6.
Further preferred compounds of the formulae IIA, IIB, IIC and IID are those wherein R21 or R22 denotes or contains a cycloalkyl or cycloalkoxy radical, preferably selected from the group consisting of
wherein S1 is C1-12-alkylene or C2-12-alkenylene and S2 is H, C1-12-alkyl or C2-12-alkenyl, and very preferably are selected from the group consisting of
Further preferred compounds of the formulae IIA, IIB, IIC and IID are indicated below.
In a preferred embodiment the LC medium comprises one or more compounds of the formula IIA selected from the group consisting of the following formulae:
in which the index a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes CH2═CH—, CH2═CHCH2CH2—, CH3—CH═CH—, CH3—CH2—CH═CH—, CH3—(CH2)2—CH═CH—, CH3—(CH2)3—CH═CH— or CH3—CH═CH—(CH2)2-.
Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae IIA-2, IIA-8, IIA-10, IIA-16, II-18, IIA-40, IIA-41, IIA-42 and IIA-43.
In another preferred embodiment the LC medium comprises one or more compounds of the formula IIB selected from the group consisting of formulae IIB-1 to IIB-26,
in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes CH2═CH—, CH2═CHCH2CH2—, CH3—CH═CH—, CH3—CH2—CH═CH—, CH3—(CH2)2—CH═CH—, CH3—(CH2)3—CH═CH— or CH3—CH═CH—(CH2)2-.
Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae IIB-2, IIB-10 and IIB-16.
In another preferred embodiment the LC medium comprises one or more compounds of the formula IIC selected from the formula IIC-1,
in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, preferably in amounts of 0.5% to 5% by weight, in particular 1% to 3% by weight.
In another preferred embodiment the LC medium comprises one or more compounds of the formula IID selected from the group consisting of the following formulae,
in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, (O) denotes an oxygen atom or a single bond, Y denotes H or CH3 and alkenyl preferably denotes CH2═CH—, CH2═CHCH2CH2—, CH3—CH═CH—, CH3—CH2—CH═CH—, CH3—(CH2)2—CH═CH—, CH3—(CH2)3—CH═CH— or CH3—CH═CH— (CH2)2-.
Further preferred LC media according to the invention comprise one or more compounds of the formula IID-1 and/or IID-4.
Further preferred LC media according to the invention comprise one or more compounds of the formula IID, wherein q is 0, Y is H and R22 denotes an alkyl or alkoxy radical having 1 to 6 C atoms wherein one CH2 group is optionally replaced by a cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl group, preferably selected from formulae IID-1, IID-15, IID-17, IID-18, IID-19, IID-20, IID-21, IID-22 and IID-23, very preferably selected from formulae IID-1, IID-21, IID-22 and IID-23.
Very preferred compounds of the formula IID are compounds selected from the following subformulae,
wherein v is 1, 2, 3, 4, 5 or 6.
In a preferred embodiment, the LC medium comprises one or more compounds of formula IID-10a
in which R21, Y and q have the meanings given in formula IID, and R23 is
in which r is 0, 1, 2, 3, 4, 5 or 6 and s is 1, 2 or 3.
Preferred compounds of formula IID-10a are selected from the following subformulae:
Particularly preferred LC media according to the invention comprise one or more compounds selected from the formulae IIA-2, IIA-8, IIA-10, IIA-16, II-18, IIA-40, IIA-41, IIA-42, IIA-43, IIB-2, IIB-10, IIB-16, IIC-1, and IID-4 and IID-10 or their subformulae.
The proportion of compounds of the formulae IIA and/or IIB in the mixture as a whole is preferably at least 20% by weight.
Preferably, the LC medium comprises one or more compounds of the formula IIA-2 selected from the following subformulae:
Alternatively, preferably in addition to the compounds of the formulae IIA-2-1 to IIA-2-5, the LC medium comprises one or more compounds of the following formulae:
Further preferably, the LC medium comprises one or more compounds of the formula IIA-10 selected from the following sub-formulae:
Alternatively, preferably in addition to the compounds of the formulae IIA-10-1 to IIA-10-5, the LC medium comprises one or more compounds of the following formulae:
Preferably, the LC medium comprises one or more compounds of the formula IIB-10 selected from the following sub-formulae:
Alternatively, preferably in addition to the compounds of the formulae IIB-10-1 to IIB-10-5, the LC medium comprises one or more compounds of the following formulae:
In another preferred embodiment the LC medium comprises one or more compounds of formula III,
in which
In the compounds of formula III R31 and R32 are preferably selected from straight-chain alkyl or alkoxy with 1 to 12, preferably 1 to 7 C atoms, straight-chain alkenyl with 2 to 12, preferably 2 to 7 C atoms and cyclic alkyl or alkoxy with 3 to 12, preferably 3 to 8 C atoms.
In a preferred embodiment of the present invention the LC medium comprises one or more compounds of formula III selected from the subformulae III-1 and III-2,
in which the occurring groups have the same meanings as given under formula III above and preferably
In another preferred embodiment the LC medium comprises one or more compounds of the formula III-1 selected from the group of compounds of subformulae III-1-1 to III-1-10, preferably of formula III-1-6,
in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl and alkenyl*each, independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms, alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy radical having 1-6 C atoms, and L11 and L12 each, independently of one another, denote F or Cl, preferably both F.
In another preferred embodiment the LC medium comprises one or more compounds of the formula III-2 selected from the group of compounds of subformulae III-2-1 to III-2-10, preferably of subformula III-2-1,
in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms, alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy radical having 1-6 C atoms, and L11 and L12 each, independently of one another, denote F or Cl, preferably both F.
Very preferred compounds of formula III-2 are selected from the group consisting of the following subformulae,
in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferably ethoxy or propoxy.
Very preferred are the compounds of formula III-2-1-3, III-2-1-4 and III-2-1-5.
In another preferred embodiment of the present invention the LC medium comprises one or more compounds of formula III selected from the formulae III-3-1 and III-3-2
in which L11 and L12 have the same meanings as given under formula III, (O) denotes O or a single bond,
The compounds of formula III-3-1 and/or III-3-2 are contained in the LC medium either alternatively or additionally to the compounds of formula III-1 and/or III-2, preferably additionally.
Very preferred compounds of the formula III-3-1 are the following,
in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms.
Very preferred compounds of the formula III-3-2 are the following,
in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferably ethoxy or propoxy.
In another preferred embodiment of the present invention, the LC medium comprises one or more compounds of the formulae III-4 to III-6, preferably of formula III-5,
in which the parameters have the meanings given above, R11 preferably denotes straight-chain alkyl and R12 preferably denotes alkoxy, each having 1 to 7 C atoms.
In another preferred embodiment of the present invention, the LC medium comprises one or more compounds of the formula III selected from the group of compounds of subformulae III-7 to III-9, preferably of subformula III-8,
in which the parameters have the meanings given above, R11 preferably denotes straight-chain alkyl and R12 preferably denotes alkoxy each having 1 to 7 C atoms.
In another preferred embodiment of the present invention, the LC medium comprises one or more compounds of formula III selected from the subformula III-10,
in which R31 and R32 have the meanings given above.
Very preferred compounds of formula III-10 are selected from the group consisting of the following formulae,
in which R32 denotes alkyl having 1 to 7 C-atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl or alternatively-(CH2)nF in which n is 2,3,4, or 5, preferably C2H4F.
In another preferred embodiment of the present invention, the LC medium comprises one or more compounds of the formula III selected of the subformula III-11,
in which R31 and R32 have the meanings given above.
Very preferred compounds of formula III-11 are selected from the group consisting of the following formulae,
in which R32 denotes alkyl having 1 to 7 C-atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl or alternatively —(CH2)nF in which n is 2,3,4, or 5, preferably C2H4F.
In a preferred embodiment, the LC medium comprises one or more compounds of the formula IV,
in which
The compounds of the formula IV are preferably selected from the group of the compounds of the formulae IV-1 to IV-4,
Preferably, the LC medium comprises one or more compounds selected from the compounds of the formulae IV-1-1 to IV-1-6:
Very preferably, the LC medium according to the invention comprises one or more compounds of the formulae IV-2-1 and/or IV-2-2
Very preferably, the LC medium according to the invention comprises a compound of formula IV-3, in particular selected from the compounds of the following subformulae:
In another preferred embodiment, the LC medium according to the invention comprises one or more compounds of formula IV-3 selected from the compounds of the following subformulae:
in which alkyl denotes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or n-pentyl.
Very preferably, the LC medium according to the invention comprises a compound of formula IV-4, in particular selected from the compounds of the following formulae:
In another preferred embodiment the LC medium comprises one or more compounds of formula IV-4 and its subformulae in which one or both of “alkenyl” and “alkenyl′” denote
in which m is 0, 1 or 2, and n is 0, 1 or 2, very preferably selected from compounds of formulae IV-4-3 to IV-4-6.
Very preferably, the LC medium according to the invention comprises one or more compounds of the formula IV-1 or its subformulae and/or one or more compounds of the formula IV-3 or its subformulae and/or one or more compounds of the formula IV-4 or its subformulae, where the total concentration of these compounds of the formula IV-1 is in the range from 1% to 30%.
The LC medium according to the invention preferably additionally comprises one or more compounds of the formula IVa,
denotes
Preferred compounds of the formula IVa are indicated below:
The LC medium according to the invention preferably comprises at least one compound of the formula IVa-1 and/or formula IVa-2.
The proportion of compounds of the formula IVa in the mixture as a whole is preferably at least 5% by weight
Preferably, the LC medium comprises one or more compounds of formula IVb-1 to IVb-3
The proportion of the compounds of the formulae IV-1 to IV-3 in the mixture as a whole is preferably at least 3% by weight, in particular ≥5% by weight.
Of the compounds of the formulae IVb-1 to IVb-3, the compounds of the formula IVb-2 are particularly preferred.
Particularly preferred compounds of the formulae IV-1 to IV-3 are selected from the group consisting of the following formulae
in which alkyl* denotes an alkyl radical having 1 to 6 C atoms and preferably denotes n-propyl.
The LC medium according to the invention particularly preferably comprises one or more compounds of the formulae IVb-1-1 and/or IVb-2-3.
In another preferred embodiment, the LC medium according to the invention comprises one or more compounds of formula V
identically or differently, denote
preferably denotes
The compounds of formula V are preferably selected from the compounds of the formulae V-1 to V-17:
Preferred LC media comprise one or more compounds of the formulae V-1, V-3, V-4, V-6, V-7, V-10, V-11, V-12, V-14, V-15, and/or V-16
LC media according to the invention very particularly preferably comprise the compounds of the formula V-10 and/or IV-1, in particular in amounts of 5 to 30%.
Preferred compounds of the formulae V-10 are indicated below:
The LC medium according to the invention particularly preferably comprises the tricyclic compounds of the formula V-10a and/or of the formula V-10b in combination with one or more bicyclic compounds of the formulae IV-1 The total proportion of the compounds of the formulae V-10a and/or V-10b in combination with one or more compounds selected from the bicyclohexyl compounds of the formula IV-1 is 5 to 40%, very particularly preferably 15 to 35%.
Particularly preferred LC media comprise the compounds V-10a and/or IV-1-1
The compounds V-10a and IV-1-1 are preferably present in the mixture in a concentration of 5 to 30%, very preferably 10 to 25%, based on the mixture as a whole.
Preferred LC media comprise at least one compound selected from the group of the compounds
In another preferred embodiment the LC medium according to the invention comprises one or more compounds of the formula V-7, preferably selected from the compounds of the formulae V-7a to V-7e:
Very preferred compounds of the formulae V-7a to V-7e are selected from the compounds of the following subformulae:
Further preferred are compounds of formula V, wherein R51 and R52 independently of one another denote straight-chain alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.
In a preferred embodiment of the present invention the LC medium additionally comprises one or more compounds of the formulae VI-1 to VI-25,
R preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.
X preferably denotes F or OCH3, very preferably F.
The LC medium according to the invention preferably comprises the terphenyls of the formulae VI-1 to VI-25 in amounts of 2 to 30% by weight, in particular 5 to 20% by weight.
Particular preference is given to compounds of the formulae VI-1, VI-2, VI-4, VI-20, VI-21, and VI-22 wherein X denotes F. In these compounds, R preferably denotes alkyl, furthermore alkoxy, each having 1 to 5 C atoms. In the compounds of the formula VI-20, R preferably denotes alkyl or alkenyl, in particular alkyl. In the compounds of the formula VI-21, R preferably denotes alkyl. In the compounds of the formulae VI-22 to VI-25, X preferably denotes F.
The terphenyls of formula VI-1 to VI-25 are preferably employed in the LC media according to the invention if the Δn value of the mixture is to be ≥0.1. Preferred LC media comprise 2 to 20% by weight of one or more terphenyl compounds selected from the group of the compounds of formulae VI-1 to VI-25.
In another preferred embodiment of the present invention the LC medium additionally comprises one or more compounds of the formulae VII-1 to VII-9
Particular preference is given to LC media comprising at least one compound of the formula VII-9.
LC medium comprising one or more substances which contain a tetrahydronaphthyl or naphthyl unit, such as, for example, the compounds of the formulae N-1 to N-5,
The LC medium according to the invention preferably comprises the compounds of the formulae BC, CR, PH-1, PH-2 in amounts of 3 to 20% by weight, in particular in amounts of 3 to 15% by weight.
Particularly preferred compounds of the formulae BC and CR are the compounds BC-1 to BC-7 and CR-1 to CR-5,
Very particular preference is given to an LC medium comprising one, two or three compounds of the formula BC-2, BF-1 and/or BF-2.
denotes
Preferred compounds of the formula In are the compounds of the formulae In-1 to In-16 indicated below:
Particular preference is given to the compounds of the formulae In-1, In-2, In-3 and In-4.
The compounds of the formula In and the sub-formulae In-1 to In-16 are preferably employed in the LC media according to the invention in concentrations ≥5% by weight, in particular 5 to 30% by weight and very particularly preferably 5 to 25% by weight.
The compounds of the formulae L-1 to L8 are preferably employed in concentrations of 5 to 15% by weight, in particular 5 to 12% by weight and very particularly preferably 8 to 10% by weight.
Preferred compounds of the formula IIA-Y are selected from the group consisting of the following subformulae
Particularly preferred compounds of the formula IIA-Y are selected from the group consisting of following subformulae:
in which Alkoxy and Alkoxy* have the meanings defined above and preferably denote methoxy, ethoxy, n-propyloxy, n-butyloxy or n-pentyloxy.
Preferred compounds of formula Q are those wherein RQ denotes straight-chain alkyl with 2 to 6 C-atoms, very preferably ethyl, n-propyl or n-butyl.
Preferred compounds of formula Q are those wherein LQ3 and LQ4 are F. Further preferred compounds of formula Q are those wherein LQ3, LQ4 and one or two of LQ1 and L92 are F.
Preferred compounds of formula Q are those wherein X° denotes F or OCF3, very preferably F.
The compounds of formula Q are preferably selected from the following subformulae
Especially preferred are compounds of formula Q1, in particular those wherein RQ is n-propyl.
Preferably the proportion of compounds of formula Q in the LC medium is from >0 to ≤5% by weight, very preferably from 0.05 to 2% by weight, more preferably from 0.1 to 1% by weight, most preferably from 0.1 to 0.8% by weight.
Preferably the LC medium contains 1 to 5, preferably 1 or 2 compounds of formula Q.
The addition of quaterphenyl compounds of formula Q to the LC mixture of a polymerizable LC medium enables to reduce ODF mura, whilst maintaining high UV absorption, enabling quick and complete polymerization, enabling strong and quick tilt angle generation, and increasing the UV stability of the LC medium.
Besides, the addition of compounds of formula Q, which have positive dielectric anisotropy, to the LC medium with negative dielectric anisotropy allows a better control of the values of the dielectric constants & and &1, and in particular enables to achieve a high value of the dielectric constant & while keeping the dielectric anisotropy As constant, thereby reducing the kick-back voltage and reducing image sticking.
The LC medium according to the invention preferably comprises
In particular, the LC medium comprises
It is advantageous for the liquid-crystalline medium according to the invention to preferably have a nematic phase from ≤−20° C. to ≥70° C., particularly preferably from ≤−30° C. to >80° C., very particularly preferably from ≤−40° C. to ≥90° C.
The LC medium according to the invention preferably has a clearing temperature of 70° C. or more, preferably of 74° C. or more.
The expression “have a nematic phase” here means on the one hand that no smectic phase and no crystallisation are observed at low temperatures at the corresponding temperature and on the other hand that clearing still does not occur on heating from the nematic phase. The investigation at low temperatures is carried out in a flow viscometer at the corresponding temperature and checked by storage in test cells having a layer thickness corresponding to the electro-optical use for at least 100 hours. If the storage stability at a temperature of −20° C. in a corresponding test cell is 1000 h or more, the LC medium is referred to as stable at this temperature. At temperatures of −30° C. and −40° C., the corresponding times are 500 h and 250 h respectively. At high temperatures, the clearing point is measured by conventional methods in capillaries.
The liquid-crystal mixture preferably has a nematic phase range of at least 60 K and a flow viscosity v20 of at most 30 mm2·s−1 at 20° C.
The mixture is nematic at a temperature of −20° C. or less, preferably at −30° C. or less, very preferably at −40° C. or less.
The values of the birefringence Δn in the liquid-crystal mixture are generally between 0.08 and 0.17, preferably between 0.09 and 0.165, very preferably between 0.10 and 0.16. In a preferred embodiment of the present invention, the LC medium has a birefringence in the range of from 0.11 to 0.155.
The liquid-crystal mixture according to the invention has a dielectric anisotropy As of −1.5 to −8.0, preferably of −2.0 to −5.0, in particular −2.5 to −4.8,
The rotational viscosity γ1 at 20° C. is preferably ≤200 mPa·s, more preferably ≤180 mPa·s, very preferably ≤125 mPa·s, most preferably ≤115 mPa·s. In another preferred embodiment, the rotational viscosity γ1 at 20° C. is ≤110 mPa·s, in particular ≤105 mPa·s.
The liquid-crystal media according to the invention have relatively low values for the threshold voltage (V0). They are preferably in the range from 1.7 V to 3.0 V, particularly preferably ≤2.7 V and very particularly preferably ≤2.5 V.
For the present invention, the term “threshold voltage” relates to the capacitive threshold (V0), also called the Freedericks threshold, unless explicitly indicated otherwise.
In addition, the liquid crystal media according to the invention have high values for the voltage holding ratio in liquid-crystal cells.
In general, liquid-crystal media having a low addressing voltage or threshold voltage exhibit a lower voltage holding ratio than those having a higher addressing voltage or threshold voltage and vice versa.
For the present invention, the term “dielectrically positive compounds” denotes compounds having a Δε>1.5, the term “dielectrically neutral compounds” denotes those having −1.5≤Δε≤1.5 and the term “dielectrically negative compounds” denotes those having Δε<−1.5. The dielectric anisotropy of the compounds is determined here by dissolving 10% of the compounds in a liquid-crystalline host and determining the capacitance of the resultant mixture in at least one test cell in each case having a layer thickness of 20 μm with homeotropic and with homogeneous surface alignment at 1 KHz. The measurement voltage is typically 0.5 V to 1.0 V, but is always lower than the capacitive threshold of the respective liquid-crystal mixture investigated.
All temperature values indicated for the present invention are in ° C.
The LC media according to the invention are suitable for all VA-TFT (vertical alignment-thin film transistor) applications, such as, for example, VAN (vertically aligned nematic), MVA (multidomain VA), (S)-PVA (super patterned VA), ASV (advanced super view, or axially symmetric VA), PSA (polymer sustained VA) and PS-VA (polymer stabilised VA). They are furthermore suitable for IPS (in-plane switching) and FFS (fringe field switching) applications having negative Δε.
The nematic LC media in the displays according to the invention generally comprise two components A and B, which themselves consist of one or more individual compounds.
Component A has significantly negative dielectric anisotropy and gives the nematic phase a dielectric anisotropy of ≤−0.5. It preferably comprises one or more of the compounds of the formulae IIA, IIB, IIC and/or IID, furthermore one or more compounds of the formula III.
The proportion of component A is preferably between 45 and 100%, in particular between 60 and 85%.
For component A, one (or more) individual compound(s) which has (have) a value of As ≤−1.5 is (are) preferably selected. This value must be more negative, the smaller the proportion A in the mixture as a whole.
Component B has pronounced nematogeneity and a flow viscosity of not greater than 30 mm2·s−1, preferably not greater than 25 mm2·s−1, at 20° C.
A multiplicity of suitable materials is known to the person skilled in the art from the literature. Particular preference is given to compounds of the formula IV.
Particularly preferred individual compounds in component B are extremely low-viscosity nematic liquid crystals having a flow viscosity of not greater than 18 mm2·s−1, preferably not greater than 12 mm2·s−1, at 20° C.
Component B is monotropically or enantiotropically nematic, has no smectic phases and is able to prevent the occurrence of smectic phases down to very low temperatures in LC media. For example, if various materials of high nematogeneity are added to a smectic liquid-crystal mixture, the nematogeneity of these materials can be compared through the degree of suppression of smectic phases that is achieved.
The mixture may optionally also comprise a component C, comprising compounds having a dielectric anisotropy of As ≥1.5. These so-called positive compounds are generally present in a mixture of negative dielectric anisotropy in amounts of ≤20% by weight, based on the mixture as a whole.
Besides the polymerizable compounds and the compounds of formula L1 and/or L2, the LC medium preferably comprises 4 to 15, in particular 5 to 12, and particularly preferably <10, compounds of the formulae IIA, IIB, IIC and/or IID and one or more compounds of the formula IV.
Besides the polymerizable compounds and the compounds of formula L1 and/or L2 and the compounds of the formulae IIA, IIB, IIC and/or IID and IV, other constituents may also be present, for example in an amount of up to 45% of the mixture as a whole, but preferably up to 35%, in particular up to 10%.
The other constituents are preferably selected from nematic or nematogenic substances, in particular known substances, from the classes of the azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenyl or cyclohexyl benzoates, phenyl or cyclohexyl cyclohexanecarboxylates, phenylcyclohexanes, cyclohexylbiphenyls, cyclohexylcyclohexanes, cyclohexylnaphthalenes, 1,4-biscyclohexylbiphenyls or cyclohexylpyrimidines, phenyl- or cyclohexyldioxanes, optionally halogenated stilbenes, benzyl phenyl ethers, tolanes and substituted cinnamic acid esters.
The most important compounds which are suitable as constituents of liquid-crystal phases of this type can be characterised by the formula R
RR1-L-G-E-RR2 R
in which L and E each denote a carbo- or heterocyclic ring system from the group formed by 1,4-disubstituted benzene and cyclohexane rings, 4,4′-disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, di- and tetrahydronaphthalene, quinazoline and tetrahydroquinazoline,
In most of these compounds, RR1 and RR2 are different from one another, one of these radicals usually being an alkyl or alkoxy group. Other variants of the proposed substituents are also common. Many such substances or also mixtures thereof are commercially available. All these substances can be prepared by methods known from the literature.
It goes without saying for the person skilled in the art that the VA, IPS or FFS mixture according to the invention may also comprise compounds in which, for example, H, N, O, CI and F have been replaced by the corresponding isotopes.
The LC medium has preferably a nematic LC phase.
The LC medium further comprises two or more polymerizable compounds, preferably selected from polymerizable mesogenic compounds, also known as “reactive mesogens” or RMs, very preferably from formula M as described above.
In the polymerizable compounds, the polymerizable group P is a group which is suitable for a polymerization reaction, such as, for example, free-radical or ionic chain polymerization, polyaddition or polycondensation, or for a polymer-analogous reaction, for example addition or condensation onto a main polymer chain. Particular preference is given to groups for chain polymerization, in particular those containing a C═C double bond or —C≡C— triple bond, and groups which are suitable for polymerization with ring opening, such as, for example, oxetane or epoxide groups. Preferred groups P are selected from the group consisting of
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)2—, Phe-CH═CH—, HOOC—, OCN— and W4W5W6Si—, in which W1 denotes H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, CI or CH3, W2 and W3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W4, W5 and W6 each, independently of one another, denote Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W7 and W8 each, independently of one another, denote H, CI or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, which is optionally substituted by one or more radicals L as defined above which are other than P-Sp-, k1, k2 and k3 each, independently of one another, denote 0 or 1, k3 preferably denotes 1, and k4 denotes an integer from 1 to 10.
Very preferred groups P are selected from the group consisting of CH2═CW1—CO—O—, CH2═CW1—CO—,
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— and W4W5W6Si—, in which W1 denotes H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, CI or CH3, W2 and W3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W4, W5 and W6 each, independently of one another, denote Cl, oxaalkyl or oxa-carbonylalkyl having 1 to 5 C atoms, W7 and W8 each, independently of one another, denote H, CI or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, k1, k2 and k3 each, independently of one another, denote 0 or 1, k3 preferably denotes 1, and k4 denotes an integer from 1 to 10.
Very particularly preferred groups P are selected from the group consisting of CH2═CW1—CO—O—, in particular CH2═CH—CO—O—, CH2═C(CH3)—CO—O— and CH2═CF—CO—O—, furthermore CH2═CH—O—, (CH2═CH)2CH—O—CO—, (CH2═CH)2CH—O—,
Further preferred polymerizable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably from acrylate and methacrylate.
Very preferably all polymerizable groups in the polymerizable compound have the same meaning.
If the spacer group Sp is different from a single bond, it is preferably of the formula Sp “-X”, so that the respective radical P-Sp-conforms to the formula P-Sp “-X”—, wherein
X″ is preferably-O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR0 —, —NR0 —CO—, —NR0 —CO—NR0— or a single bond.
Typical spacer groups Sp and -Sp “-X”are, for example, —(CH2)p1—, —(CH2)p1—O—, —(CH2)p1—O—CO—, —(CH2)p1—CO—O—, —(CH2)p1—O—CO—O—, —(CH2CH2O)q1—CH2CH2—, —CH2CH2—S—CH2CH2—, —CH2CH2—NH—CH2CH2— or —(SiROR00—O)p1—, in which p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R0 and R00 have the meanings indicated above.
Particularly preferred groups Sp and -Sp “-X”-are —(CH2)p1—, —(CH2)p1—O—, —(CH2)p1—O— CO—, —(CH2)p1—CO—O—, —(CH2)p1—O—CO—O—, in which p1 and q1 have the meanings indicated above.
Particularly preferred groups Sp” are, in each case straight-chain, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.
In a preferred embodiment of the invention the polymerizable compounds contain a spacer group Sp that is substituted by one or more polymerizable groups P, so that the group Sp-P corresponds to Sp (P) s, with s being ≥2 (branched polymerizable groups).
Preferred polymerizable compounds according to this preferred embodiment are those wherein s is 2, i.e. compounds which contain a group Sp (P)2. Very preferred polymerizable compounds according to this preferred embodiment contain a group selected from the following formulae:
-X-alkyl-CHPP S1
-X-alkyl-CH((CH2)aaP)((CH2)bbP) S2
-X-N((CH2)aaP)((CH2)bbP) S3
-X-alkyl-CHP-CH2—CH2P S4
-X-alkyl-C(CH2P)(CH2P)—CaaH2aa+1 S5
-X-alkyl-CHP-CH2P S6
-X-alkyl-CPP-CaaH2aa+1 S7
-X-alkyl-CHPCHP-CaaH2aa+1 S8
Preferred spacer groups Sp (P)2 are selected from formulae S1, S2 and S3.
Very preferred spacer groups Sp (P)2 are selected from the following subformulae:
—CHPP S1a
—O—CHPP S1b
—CH2—CHPP S1c
—OCH2—CHPP S1d
—CH(CH2—P)(CH2—P) S2a
—OCH(CH2—P)(CH2—P) S2b
—CH2—CH(CH2—P)(CH2—P) S2c
—OCH2—CH(CH2—P)(CH2—P) S2d
—CO—NH((CH2)2P)((CH2)2P) S3a
P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, very preferably from acrylate and methacrylate, most preferably from methacrylate.
Further preferably all polymerizable groups P that are present in the same compound have the same meaning, and very preferably denote acrylate or methacrylate, most preferably methacrylate.
Sp preferably denotes a single bond or —(CH2)p1—, —(CH2)p2—CH═CH—(CH2)p3—, —O— (CH2)p1—, —O—CO—(CH2)p1, or —CO—O—(CH2)p1, wherein p1 is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 are independently of each other 0, 1, 2 or 3 and, if Sp is-O—(CH2)p1—, —O—CO—(CH2)p1 or —CO—O—(CH2)p1 the O-atom or CO-group, respectively, is linked to the benzene ring.
Further preferably at least one group Sp is a single bond.
Further preferably at least one group Sp is different from a single bond, and is preferably selected from —(CH2)p1—, —(CH2)p2—CH═CH—(CH2)p3—, —O—(CH2)p1—, —O—CO—(CH2)p1, or —CO—O—(CH2)p1, wherein p1 is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 are independently of each other 0, 1, 2 or 3 and, if Sp is —O—(CH2)p1—, —O—CO—(CH2)p1 or —CO—O—(CH2)p1 the O-atom or CO-group, respectively, is linked to the benzene ring.
Very preferably Sp is different from a single bond, and is selected from —(CH2)2—, —(CH2)3—, —(CH2)4—, —O—(CH2)2—, —O—(CH2)3—, —O—CO—(CH2)2 and -CO—O—(CH)2—, wherein the O atom or the CO group is attached to the benzene ring.
Particularly preferred compounds of the formula M are those in which B1 and B2 each, independently of one another, denote 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, coumarine, flavone, where, in addition, one or more CH groups in these groups may be replaced by N, cyclohexane-1,4-diyl, in which, in addition, one or more non-adjacent CH2 groups may 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, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl or octahydro-4,7-methanoindane-2,5-diyl, where all these groups may be unsubstituted or mono- or polysubstituted by L as defined above.
Particularly preferred compounds of the formula M are those in which B1 and B2 each, independently of one another, denote 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl or naphthalene-2,6-diyl.
Further preferred compounds of the formula M are those in which the group -B1-(ZmB2)m— in formula M is selected from the following formulae
wherein at least one benzene ring is substituted by at last one group L and the benzene rings are optionally further substituted by one or more groups L or P-Sp-.
Preferred compounds of formula M and its sub-formulae are selected from the following preferred embodiments, including any combination thereof:
Very preferred compounds of formula M are selected from the following formulae:
in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning:
Very preferred are compounds of formulae M2, M13 and M32, especially direactive compounds containing exactly two polymerizable groups P1 and P2.
Further preferred are compounds selected from formulae M17 to M31, in particular from formulae M20, M22, M26, M29 and M31, especially trireactive compounds containing exactly three polymerizable groups P1, P2 and P3.
In the compounds of formulae M1 to M32 the group
is preferably
wherein L on each occurrence, identically or differently, has one of the meanings given above or below, and is preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3) C2H5, —CH═CH2, C(CH3)═CH2, SCH3, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, —CH═CH2, C(CH3)═CH2, SCH3, OCH3, COCH3, OCF3 or P-Sp-, more preferably F, Cl, CH3, —CH═CH2, C(CH3)═CH2, SCH3, OCH3, COCH3 or OCF3, most preferably F, SCH3 or OCH3.
Preferred compounds of formulae M1 to M32 are those wherein P1, P2 and P3 denote an acrylate, methacrylate, oxetane or epoxy group, very preferably an acrylate or methacrylate group, most preferably a methacrylate group.
Further preferred compounds of formulae M1 to M32 are those wherein Sp1, Sp2 and Sp3 are a single bond.
Further preferred compounds of formulae M1 to M32 are those wherein one of Sp1, Sp2 and Sp3 is a single bond and another one of Sp1, Sp2 and Sp3 is different from a single bond.
Further preferred compounds of formulae M1 to M32 are those wherein those groups Sp1, Sp2 and Sp3 that are different from a single bond denote —(CH2)s1—X″—, wherein s1 is an integer from 1 to 6, preferably 2, 3, 4 or 5, and X″ is X″ is the linkage to the benzene ring and is-O—, —O—CO—, —CO—O, —O—CO—O— or a single bond.
Further preferred polymerizable compounds are selected from Table E below, especially selected from the group consisting of formulae RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-58, RM-64, RM-74, RM-76, RM-88, RM-91, RM-102, RM-103, RM-109, RM-116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-140, RM-142, RM-143, RM-145, RM-146, RM-147, RM-149, RM-156 to RM-163, RM-169, RM-170 and RM-171 to RM-183.
Particularly preferred are LC media comprising two, three or more polymerizable compounds of formula M.
Further preferred are LC media comprising two or more direactive polymerizable compounds of formula M, preferably selected from formulae M1 to M16 and M32, very preferably selected from formulae M2, M13 and M32.
Further preferred are LC media comprising one or more direactive polymerizable compounds of formula M, preferably selected from formulae M1 to M16 and M32, very preferably from formulae M2, M13 and M32, and one or more trireactive polymerizable compounds of formula M, preferably selected from formulae M17 to M32, very preferably from formulae M20, M22, M26, M29 and M31.
Further preferred are LC media comprising one or more polymerizable compounds of formula M wherein at least one r is not 0, or at least one of s and t is not 0, very preferably selected from formulae M2, M13, M22, M24, M27, M29, M31 and M32, and wherein L is selected from the preferred groups shown above, most preferably from F, OCH3 and SCH3.
Further preferred are LC media comprising one or more polymerizable compounds which show absorption in the wavelength range from 320 to 380 nm, preferably selected from formula M, very preferably from formulae M1 to M32.
Particular preference is given to LC media comprising two or more, very preferably two or three, polymerizable compounds selected from formula M or formulae M1 to M32.
The combination of compounds of the preferred embodiments mentioned above with the polymerized compounds described above and below causes low threshold voltages, low rotational viscosities and very good low-temperature stabilities in the LC media according to the invention at the same time as constantly high clearing points and high HR values, and allows the rapid establishment of a particularly low tilt angle (i.e. a large tilt) in PSA displays. In particular, the LC media exhibit significantly shortened response times, in particular also the grey-shade response times, in PSA displays compared with the LC media from the prior art.
For use in PSA displays the total proportion of the polymerizable compounds, like those of formula M or M1 to M32, in the LC medium is preferably from 0.01 to 2.0%, very preferably from 0.1 to 1.0%, most preferably from 0.2 to 0.8%.
For use in SA-VA displays the total proportion of the polymerizable compounds, like those of formula M or M1 to M32, in the LC medium is preferably from >0 to <3%, very preferably from >0 to <2%, more preferably from 0.05 to 2.0, most preferably from 0.05 to 1.0%.
In a preferred embodiment of the present invention the LC medium comprises two or more polymerizable compounds of formula M selected from formulae IA, IB and IC:
P-Sp-M1-Sp-P IA
P-Sp-M2-Sp-P IB
P-Sp-M3-Sp-P IC
in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meanings:
In a preferred embodiment of the invention the compounds of formula IA and its subformulae contain a spacer group Sp that is substituted by one or more, preferably by one, group La.
In the compounds of formula IA and its subformulae, Raa and Rbb preferably denote straight chain alkyl with 1 to 6 C atoms or branched alkyl with 3 to 6 C atoms. More preferably Raa and Rob denote, independently of each other, methyl, ethyl, propyl and butyl, very preferably methyl or ethyl, most preferably methyl.
Further preferred are compounds of formula IA and its subformulae as described above and below, wherein Raa and Rob together with the C atom to which they are attached form a cyclic alkyl group with 3 to 12 C atoms, very preferably a cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl group.
Very preferably the compounds of formula IA contain a group La selected from the following formulae:
wherein the asterisk denotes the linkage to the adjacent group in the compound of formula I.
In another preferred embodiment of the invention the compounds of formula IA and its subformulae contain a spacer group Sp that is a linear or branched alkylene with 1 to 12, preferably 1 to 7 C atoms which is substituted by one or more groups La. Preferred compounds of formula IA according to this preferred embodiment contain a group P-Sp-selected from the following formulae:
P—CHLa- SL1
P—(CH2)cc—O—CHLa- SL2
P—(CH2)cc—CO—O—CHLa- SL3
P—(CH2)cc—CHLa- SL4
in which P and La are as defined in formula I or have one of the meanings given above and below, and cc is 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3.
Preferred compounds of formula I contain one or more groups P-Sp-selected from formulae SL1, SL2 and SL3, very preferably of formula SL1.
Preferably in the compounds of formula IA M1 is selected of formula 1 or 2.
Preferred compounds of formula IA are selected from the following subformulae:
wherein P, Sp and L have the meanings given in formula IA or one of the preferred meanings as given above and below,
Very preferred compounds of subformulae IA-1 to IA-10 are those wherein all groups P are identical and denote acrylate or methacrylate, preferably methacrylate.
Further preferred compounds of subformulae IA-1 to IA-10 are those wherein at least one group Sp denotes a single bond.
Further preferred compounds of subformulae IA-1 to IA-10 are those wherein one group Sp is selected from formulae SL1 to SL4, very preferably from formula SL1, and the other groups Sp denote a single bond or, if being different from a single bond, denote is, —(CH2)p1—, —(CH2)p1—O—, —(CH2)p1—O—CO— or —(CH2)p1—CO—O—, in which p1 is an integer from 1 to 12, preferably 1 to 6, and the O— or CO-group is connected to the benzene ring, very preferably wherein the other groups Sp denote single bonds.
Further preferred compounds of formula IA and its subformulae are selected from the following preferred embodiments, including any combination thereof:
Very preferred compounds of formula IA and its subformulae are selected from the following list:
wherein “Me” is methyl and “Et” is ethyl.
In a preferred embodiment the LC medium comprises one or more compounds of formula IB having two polymerizable groups, which are preferably selected from formula IB-D
wherein P and Sp have the meanings given in formula IB, L has one of the meanings given in formula IB which is different from P-Sp-, r1, r2 and r3 are independently of each other 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 0 or 1, and k is 0 or 1.
Preferred compounds of formula IB-D are selected from the following subformulae
wherein P and Sp, L, r1, r2 and r3 have independently of each other one of the meanings given in formula IB-D or one of their preferred meanings as given above and below.
Especially preferred are the compounds of formula IB-D-1.
In the compounds of formula IB-D preferably at least one of r1, r2 and r3 is not 0. P is preferably acrylate or methacrylate, very preferably methacrylate. Preferably all groups P in the formulae IB-D, IB-D-1 and IB-D-2 have the same meaning, and very preferably denote methacrylate. Sp” is preferably selected from —(CH2)2—, —(CH2)3—, —(CH2)4—, —O—(CH2)2—, —O—(CH2)3—, —O—CO—(CH2)2 and -CO—O—(CH)2—, wherein the O atom or the CO group is attached to the benzene ring. L is preferably selected from F, CH3, OCH3, OC2H5 and C2H5, very preferably from F.
Very preferred compounds of formula IB-D are selected from the following subformulae:
Very preferred are the compounds of formula IBD1, IBD4, IBD6, IBD7, IBD19, IBD21 and IBD23.
Further preferred are the compounds of formulae IBD1 to IBD25 wherein one or two of the methacrylate groups are replaced by acrylate groups.
Further preferred compounds of formula IB-D are selected from Table D below, very preferably from the group consisting of RM-1, RM-2, RM-3, RM-7 to RM-49 and RM-58 to RM-77, very preferably selected from the group consisting of RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-58, RM-64, RM-72 and RM-74.
In another preferred embodiment the LC medium comprises one or more polymerizable compounds of formula IB having three polymerizable groups, which are preferably selected from formula IB-T
wherein P, Sp, L, r1, r2 and k independently of each other have the meanings given in formula IB-D or one of their preferred meanings as given above and below, and r4 is 0, 1, 2 or 3, preferably 0, 1 or 2, very preferably 0 or 1.
Preferred compounds of formula IB-T are selected from the following subformulae
wherein P, Sp, L, r1, r2 and r4 have independently of each other one of the meanings given in formula IB-T or one of their preferred meanings as given above and below. Preferably at least one of r1, r2 and r4 is not 0. P is preferably acrylate or methacrylate, very preferably methacrylate. L is preferably selected from F, CH3, OCH3, OC2H5 and C2H5, very preferably from OCH3 or F. Preferably all groups P in the formulae IB-T and IB-T-1 to IB-T-6 have the same meaning, and very preferably denote methacrylate.
Especially preferred are the compounds of formula IB-T-1, IB-T-4 and IB-T-5.
Very preferred compounds of formula IB-T are selected from the following subformulae:
Of the compounds of formula IBT1 to IB-T21 with two benzene rings very preferred are the compounds of formula IBT1, IBT2, IBT3, IBT8, IBT9, IBT10, IBT15, IBT16, IBT17. Most preferred are the compounds of formula IBT1, IBT2, IBT3, IBT8, IBT9 and IB10.
Of the compounds of formula IBT22 to IBT53 with three benzene rings very preferred are the compounds of formula IBT22 to IBT46. Most preferred are the compounds of formula IBT22, IBT28, IBT29, IBT35 and IBT36.
Further preferred are the compounds of formulae IBT1 to IBT53 wherein one or two of the methacrylate groups are replaced by acrylate groups.
Further preferred are the compounds of formulae IBT1 to IBT53 wherein all methacrylate groups are replaced by acrylate groups.
In another preferred embodiment the LC medium contains at least one compound of formula IC, which is at least monosubstituted by an alkenyl group Lb. Preferred compounds of formula IC of this preferred embodiment are selected from the following subformulae:
wherein P, Sp, L, r1, r2, r3 and r4 have the meanings given in formula IB-D and IB-T or one of the preferred meanings as given above and below, with r1+r2+r3+r4 ≥1, and wherein the compounds contain at least one group L that denotes Lb.
In the compounds of formulae IC-1 to IC-9 preferably L′ denotes —CH═CH2, —CH2—CH═CH2, —CH═CH—CH3, —CH═CH—CH═CH2 or —C(CH3)═CH2, very preferably —CH—CH2 or C(CH3)═CH2.
In the compounds of formulae IC-1 to IC-9 preferably P is acrylate or methacrylate, very preferably methacrylate. If Sp is different from a single bond, it is preferably selected from —(CH2)2—, —(CH2)3—, —(CH2)4—, —O—(CH2)2—, —O—(CH2)3—, —O—CO—(CH2)2 and -CO—O—(CH)2—, wherein the O atom or the CO group is attached to the benzene ring. L is preferably selected from F, CH3, OCH3, OC2H5 or C2H5, very preferably from OCH3 or F. Preferably all groups P in the formulae IC-1 to IC-9 have the same meaning, and very preferably denote methacrylate.
Very preferred compounds of formulae IC-1 to IC-9 are selected from the following subformulae:
Further preferred are compounds of formula IC1 to IC46 wherein one, two or all of the methacrylate groups are replaced by acrylate groups.
In a preferred embodiment the LC medium comprises at least one polymerizable compound of formula IA and/or formula IB and/or formula IC which have absorption in the range from 330 to 390 nm. Very preferably these compounds have an extinction coefficient of at least 0.5 at a wavelength in the range from 330 to 390 nm, more preferably in the range from 340 to 380 nm, very preferably in the range from 350 to 370 nm, most preferably in the range from 355 to 365 nm. The extinction coefficient and absorption wavelength are measured unless stated otherwise in a solution of the compound in DCM at a concentration of 3 g/L.
The total proportion of the polymerizable compounds of formulae IA, IB, IC and their subformulae in the LC medium according to the present invention is preferably from 0.05 to 3.0%, more preferably from 0.1 to 1.5%, very preferably from 0.1 to 0.9%.
In a first preferred embodiment of the present invention, the LC medium contains one or more, preferably exactly one, compound(s) of formula IA or its subformulae and one or more, preferably exactly one, compound(s) of formula IB or IC their subformulae, and preferably does not contain further polymerizable compounds.
Preferably, in the LC medium of this first preferred embodiment the proportion of the compound(s) of formula IA or its subformulae is from 0.01 to 1.0%, more preferably from 0.05 to 0.8%, very preferably from 0.1 to 0.6%, and the proportion of the compound(s) of formula IB od IC or their subformulae is from 0.01 to 1.0%, more preferably from 0.02 to 0.8%, very preferably from 0.05 to 0.5%.
In a second preferred embodiment of the present invention, the LC medium contains one or more, preferably exactly one, compound(s) of formula IA or its subformulae, one or more, preferably exactly one, compound(s) of formula IB or their subformulae, and one or more, preferably exactly one, compound(s) of formula IC or their subformulae, and preferably does not contain further polymerizable compounds.
More preferably the LC medium of this second preferred embodiment contains one or more, preferably exactly one, compound(s) of formula IA or its subformulae, one or more, preferably exactly one, compound(s) of formula IB-D or IB-T or their subformulae, and one or more, preferably exactly one, compound(s) selected from formulae IC-1 to IC-9 or their subformulae, and preferably does not contain further polymerizable compounds.
Preferably, in the LC medium of this second preferred embodiment the proportion of the compound(s) of formula IA or its subformulae is from 0.01 to 1.0%, more preferably from 0.05 to 0.8%, very preferably from 0.1 to 0.6%, the total proportion of the compound(s) of formula IB-D and IB-T or their subformulae is from 0.01 to 1.0%, more preferably from 0.05 to 0.8%, very preferably from 0.1 to 0.6%, and the total proportion of the compound(s) of the formulae IC-1 to IC-9 or their subformulae is from 0.01 to 1.0%, more preferably from 0.02 to 0.8%, very preferably from 0.05 to 0.5%.
In another preferred embodiment the LC medium comprises, in addition to the polymerizable compounds of formulae IA, IB, IC and their subformulae, at least one further polymerizable compound.
The compounds of the formulae M and its subformulae can be prepared analogously to processes known to the person skilled in the art and described in standard works of organic chemistry, such as, for example, in Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart.
For example, acrylic or methacrylic esters can be prepared by esterification of the corresponding alcohols with acid derivatives like, for example, (meth)acryloyl chloride or (meth)acrylic anhydride in the presence of a base like pyridine or triethyl amine, and 4-(N,N-dimethylamino)pyridine (DMAP). Alternatively the esters can be prepared by esterification of the alcohols with (meth)acrylic acid in the presence of a dehydrating reagent, for example according to Steglich with dicyclohexylcarbodiimide (DCC), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC) or N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride and DMAP.
The invention furthermore relates to an LC medium or LC display as described above, wherein the polymerizable compounds, like those of formula M and its subformulae, are present in polymerized form.
Optionally one or more polymerization initiators are added to the LC medium. Suitable conditions for the polymerization and suitable types and amounts of initiators are known to the person skilled in the art and are described in the literature. Suitable for free-radical polymerization are, for example, the commercially available photoinitiators Irgacure651®, Irgacure184®, Irgacure907®, Irgacure369® or Darocure1173® (Ciba AG). If a polymerization initiator is employed, its proportion is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.
The polymerizable compounds according to the invention are also suitable for polymerization without an initiator, which is accompanied by considerable advantages, such, for example, lower material costs and in particular less contamination of the LC medium by possible residual amounts of the initiator or degradation products thereof. The polymerization can thus also be carried out without the addition of an initiator. In a preferred embodiment, the LC medium thus does not contain a polymerization initiator.
The LC medium may also comprise one or more stabilisers in order to prevent undesired spontaneous polymerization of the RMs, for example during storage or transport. Suitable types and amounts of stabilisers are known to the person skilled in the art and are described in the literature. Particularly suitable are, for example, the commercially available stabilisers from the Irganox® series (Ciba AG), such as, for example, Irganox® 1076. If stabilisers are employed, their proportion, based on the total amount of RMs or the polymerizable component (component A), is preferably 10-50,000 ppm, particularly preferably 50-5,000 ppm.
In a preferred embodiment the LC media contain one or more chiral dopants, preferably in a concentration from 0.01 to 1% by weight, very preferably from 0.05 to 0.5% by weight. The chiral dopants are preferably selected from the group consisting of compounds from Table C below, very preferably from the group consisting of R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011, and R- or S-5011.
In another preferred embodiment the LC media contain a racemate of one or more chiral dopants, which are preferably selected from the chiral dopants mentioned in the previous paragraph.
In another preferred embodiment of the present invention the LC media contain one or more further stabilisers.
Preferred stabilisers are selected from the compounds of formula H
in which
The compounds of formula H are described in EP3354710 A1 and EP3354709 A1.
Preferred compounds of formula H are selected from the formulae H-1, H-2 and H-3:
in which RH has the meanings given above and preferably denotes H or O′, and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7, and Sp denotes a spacer group, preferably alkylene having 1 to 12 C atoms in which one or more non-adjacent —CH2— groups may be replaced with —O—.
Preferred compounds of formula H-1 are those of formula H-1-1:
in which RH has the meanings given above and preferably denotes H or O, and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.
Very preferred compounds of formula H-1-1 are those of formula H-1-1-1:
Preferred compounds of formula H-2 are those of formula H-2-1:
in which RH has the meanings given above and preferably denotes H or O′, and n2, on each occurrence identically or differently, preferably identically, is an integer from 1 to 12, preferably 2, 3, 4, 5, or 6, very preferably 3, and R$ on each occurrence identically or differently, preferably identically, denotes alkyl having 1 to 6 C atoms, preferably n-butyl.
Very preferred compounds of formula H-2-1 are those of formula H-2-1-1:
Preferred compounds of formula H-3 are selected from the formula H-3-1:
in which Sp and RH have the meanings given above and RH preferably denotes H or O, and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7. Further preferred stabilisers are selected from the group consisting of the formulae ST-1 to ST-18:
in which
—O—, —CO—O—, —O—CO— in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen,
on each occurrence, identically or differently, denotes
Preferred compounds of formula ST are those selected from the formulae ST-3 and in particular:
in which n=1, 2, 3, 4, 5, 6 or 7, preferably n=3
in which n=1, 2, 3, 4, 5, 6 or 7, preferably n=3
in which n=1, 2, 3, 4, 5, 6 or 7, preferably n=1 or 7
In the compounds of the formulae ST-3a and ST-3b, n preferably denotes 3. In the compounds of the formula ST-2a, n preferably denotes 7.
Very preferred stabilisers are selected from the group of the compounds of the formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1 and ST-12:
In another preferred embodiment the LC medium comprises one or more stabilisers selected from Table D below.
Preferably the proportion of stabilisers in the LC medium is from 10 to 500 ppm, very preferably from 20 to 100 ppm.
In another preferred embodiment the LC medium according to the present invention contains a self alignment (SA) additive, preferably in a concentration of 0.1 to 2.5%.
In a preferred embodiment the SA-VA display according to the present invention does not contain a polyimide alignment layer. In another preferred embodiment the SA-VA display according to preferred embodiment contains a polyimide alignment layer.
Preferred SA additives for use in this preferred embodiment are selected from compounds comprising a mesogenic group and a straight-chain or branched alkyl side chain that is terminated with one or more polar anchor groups selected from hydroxy, carboxy, amino or thiol groups.
Further preferred SA additives contain one or more polymerizable groups which are attached, optionally via spacer groups, to the mesogenic group. These polymerizable SA additives can be polymerized in the LC medium under similar conditions as applied for the RMs in the PSA process.
Suitable SA additives to induce homeotropic alignment, especially for use in SA-VA mode displays, are disclosed for example in US 2013/0182202 A1, US 2014/0838581 A1, US 2015/0166890 A1 and US 2015/0252265 A1.
In another preferred embodiment an LC medium or a polymer stabilised SA-VA display according to the present invention contains one or more self alignment additives selected from Table F below.
In another preferred embodiment the LC medium according to the present invention contains one or more SA additives, preferably selected from formula II or its subformulae or selected from Table F below, in a concentration from 0.1 to 5%, very preferably from 0.2 to 3%, most preferably from 0.2 to 1.5%.
The invention furthermore relates to an LC display comprising an LC medium according to the invention as described above and below, which is a preferably a PSA or SA display, very preferably a PS-VA, PS-IPS, PS-FFS or SA-VA display.
The invention furthermore relates to an LC display comprising an LC medium as described above and below wherein the polymerizable compounds are present in polymerized form, which is preferably a PSA or SA display, very preferably a PS-VA, PS-IPS, PS—FFS or SA-VA display.
For the production of PSA or polymer stabilised SA displays, the polymerizable compounds contained in the LC medium are polymerized by in-situ polymerization in the LC medium between the substrates of the LC display, preferably while a voltage is applied to the electrodes.
The structure of the displays according to the invention corresponds to the usual geometry for PSA displays, as described in the prior art cited at the outset. Geometries without protrusions are preferred, in particular those in which, in addition, the electrode on the colour filter side is unstructured and only the electrode on the TFT side has slots. Particularly suitable and preferred electrode structures for PS-VA displays are described, for example, in US 2006/0066793 A1.
A preferred PSA type LC display of the present invention comprises:
The first and/or second alignment layer controls the alignment direction of the LC molecules of the LC layer. For example, in PS-VA displays the alignment layer is selected such that it imparts to the LC molecules homeotropic (or vertical) alignment (i.e. perpendicular to the surface) or tilted alignment. Such an alignment layer may for example comprise a polyimide, which may also be rubbed, or may be prepared by a photoalignment method.
The LC layer with the LC medium can be deposited between the substrates of the display by methods that are conventionally used by display manufacturers, for example the so-called one-drop-filling (ODF) method. The polymerizable component of the LC medium is then polymerized for example by UV photopolymerization. The polymerization can be carried out in one step or in two or more steps. The PSA display may comprise further elements, like a colour filter, a black matrix, a passivation layer, optical retardation layers, transistor elements for addressing the individual pixels, etc., all of which are well known to the person skilled in the art and can be employed without inventive skill.
The electrode structure can be designed by the skilled person depending on the individual display type. For example for PS-VA displays a multi-domain orientation of the LC molecules can be induced by providing electrodes having slits and/or bumps or protrusions in order to create two, four or more different tilt alignment directions.
Upon polymerization the polymerizable compounds form a copolymer, which causes a certain tilt angle of the LC molecules in the LC medium. Without wishing to be bound to a specific theory, it is believed that at least a part of the crosslinked polymer, which is formed by the polymerizable compounds, will phase-separate or precipitate from the LC medium and form a polymer layer on the substrates or electrodes, or the alignment layer provided thereon. Microscopic measurement data (like SEM and AFM) have confirmed that at least a part of the formed polymer accumulates at the LC/substrate interface.
The polymerization can be carried out in one step. It is also possible firstly to carry out the polymerization, optionally while applying a voltage, in a first step in order to produce a tilt angle, and subsequently, in a second polymerization step without an applied voltage, to polymerize or crosslink the compounds which have not reacted in the first step (“end curing”).
Suitable and preferred polymerization methods are, for example, thermal or photopolymerization, preferably photopolymerization, in particular UV induced photopolymerization, which can be achieved by exposure of the polymerizable compounds to UV radiation.
The polymerizable compounds of formula M and its subformulae do in particular show good UV absorption in, and are therefore especially suitable for, a process of preparing a PSA display including one or more of the following features or any combination thereof:
Both using lower intensity and a UV shift to longer wavelengths protect the organic layer against damage that may be caused by the UV light.
A preferred embodiment of the present invention relates to a process for preparing a PSA display as described above and below, comprising one or more of the following features or any combination thereof:
This preferred process can be carried out for example by using the desired UV lamps or by using a band pass filter and/or a cut-off filter, which are substantially transmissive for UV light with the respective desired wavelength(s) and are substantially blocking light with the respective undesired wavelengths. For example, when irradiation with UV light of wavelengths λ of 300-400 nm is desired, UV exposure can be carried out using a wide band pass filter being substantially transmissive for wavelengths 300 nm<λ<400 nm. When irradiation with UV light of wavelength 2 of more than 340 nm is desired, UV irradiation can be carried out using a cut-off filter being substantially transmissive for wavelengthsλ<340 nm.
In a preferred embodiment of the present invention, UV irradiation is carried out using a UV-LED lamp.
The use of UV-LED lamps, which have with only one narrow emission peak, in the PSA process provides several advantages, like for example a more effective optical energy transfer to the polymerizable compounds in the LC medium, depending on the choice of the suitable polymerizable compounds that shows absorption at the emission wavelength of the LED lamp. This allows to reduce the UV intensity and/or the UV irradiation time, thus enabling a reduced tact time and savings in energy and production costs. Another advantage is that the narrow emission spectrum of the lamp allows an easier selection of the appropriate wavelength for photopolymerization.
Very preferably the UV light source is an UV-LED lamp emitting a wavelength in the range from 340 to 400 nm, more preferably in the range from 340 to 380 nm. UV-LED lamps emitting UV light with a wavelength of 365 nm are especially preferred.
Preferably the UV-LED lamp emits light having an emission peak with a full width half maximum (FWHM) of 30 nm or less.
UV-LED lamps are commercially available, for example from Dr. Hoenle AG, Germany or Primelite GmbH, Germany, or IST Metz GmbH, Germany, with emission wavelengths e.g. of 365, 385, 395 and 405 nm.
This preferred process enables the manufacture of displays by using longer UV wavelengths, thereby reducing or even avoiding the hazardous and damaging effects of short UV light components.
UV radiation energy is in general from 6 to 100 J, depending on the production process conditions.
The LC medium according to the present invention may additionally comprise one or more further components or additives, preferably selected from the list including but not limited to co-monomers, chiral dopants, polymerization initiators, inhibitors, stabilisers, surfactants, wetting agents, lubricating agents, dispersing agents, hydrophobing agents, adhesive agents, flow improvers, defoaming agents, deaerators, diluents, reactive diluents, auxiliaries, colourants, dyes, pigments and nanoparticles.
Furthermore, it is possible to add to the LC media, for example, 0 to 15% by weight of pleochroic dyes, furthermore nanoparticles, conductive salts, preferably ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutylammonium tetraphenylborate or complex salts of crown ethers (cf., for example, Haller et al., Mol. Cryst. Liq. Cryst. 24, 249-258 (1973)), for improving the conductivity, or substances for modifying the dielectric anisotropy, the viscosity and/or the alignment of the nematic phases. Substances 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.
The individual components of the above-listed preferred embodiments of the LC media according to the invention are either known or methods for the preparation thereof can readily be derived from the prior art by the person skilled in the relevant art, since they are based on standard methods described in the literature. Corresponding compounds of the formula CY are described, for example, in EP-A-0 364 538. Corresponding compounds of the formula ZK are described, for example, in DE-A-26 36 684 and DE-A-33 21 373.
The LC media which can be used in accordance with the invention are prepared in a manner conventional per se, for example by mixing one or more of the above-mentioned compounds with one or more polymerizable compounds as defined above, and optionally with further liquid-crystalline compounds and/or additives. In general, the desired amount of the components used in lesser amount is dissolved in the components making up the principal constituent, advantageously at elevated temperature. It is also possible to mix solutions of the components in an organic solvent, for example in acetone, chloroform or methanol, and to remove the solvent again, for example by distillation, after thorough mixing. The invention furthermore relates to the process for the preparation of the LC media according to the invention.
It goes without saying to the person skilled in the art that the LC media according to the invention may also comprise compounds in which, for example, H, N, O, Cl, F have been replaced by the corresponding isotopes like deuterium etc.
The following examples explain the present invention without restricting it. However, they show the person skilled in the art preferred mixture concepts with compounds preferably to be employed and the respective concentrations thereof and combinations thereof with one another. In addition, the examples illustrate which properties and property combinations are accessible.
For the present invention and in the following examples, the structures of the liquid-crystal compounds are indicated by means of acronyms. Unless stated otherwise, the transformation into chemical formulae is done in accordance with Tables A.1 to A.3 below. All radicals CnH2n+1, CmH2m+1 and CH2+1 or CnH2n, CmH2m and CIH2I are straight-chain alkyl radicals or alkylene radicals, in each case having n, m and I C atoms respectively. Preferably n, m and I are independently of each other 1, 2, 3, 4, 5, 6, or 7. Table A.1 shows the codes for the ring elements of the nuclei of the compound, Table A.2 lists the bridging units, and Table A.3 lists the meanings of the symbols for the left- and right-hand end groups of the molecules. The acronyms are composed of the codes for the ring elements with optional linking groups, followed by a first hyphen and the codes for the left-hand end group, and a second hyphen and the codes for the right-hand end group.
in which n and m are each integers, and the three dots “ . . . ” are placeholders for other abbreviations from this table.
Table B shows illustrative structures of compounds together with their respective abbreviations.
In a preferred embodiment of the present invention, the LC media according to the invention comprise one or more compounds selected from the group consisting of compounds from Table B.
C 15
CB 15
CM 21
R/S-811
CM 44
CM 45
CM 47
R/S-1011
R/S-2011
R/S-3011
R/S-4011
R/S-5011
The LC media preferably comprise 0 to 10% by weight, in particular 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight, of dopants. The LC media preferably comprise one or more dopants selected from the group consisting of compounds from Table C.
The LC media preferably comprise 0 to 10% by weight, in particular 1 ppm to 5% by weight, particularly preferably 1 ppm to 1% by weight, of stabilisers. The LC media preferably comprise one or more stabilisers selected from the group consisting of compounds from Table D.
RM-1
RM-2
RM-3
RM-4
RM-5
RM-6
RM-7
RM-8
RM-9
RM-10
RM-11
RM-12
RM-13
RM-14
RM-15
RM-16
RM-17
RM-18
RM-19
RM-20
RM-21
RM-22
RM-23
RM-24
RM-25
RM-26
RM-27
RM-28
RM-29
RM-30
RM-31
RM-32
RM-33
RM-34
RM-35
RM-36
RM-37
RM-38
RM-39
RM-40
RM-41
RM-42
RM-43
RM-44
RM-45
RM-46
RM-47
RM-48
RM-49
RM-50
RM-51
RM-52
RM-53
RM-54
RM-55
RM-56
RM-57
RM-58
RM-59
RM-60
RM-61
RM-62
RM-63
RM-64
RM-65
RM-66
RM-67
RM-68
RM-69
RM-70
RM-71
RM-72
RM-73
RM-74
RM-75
RM-76
RM-77
RM-78
RM-79
RM-80
RM-81
RM-82
RM-83
RM-84
RM-85
RM-86
RM-87
RM-88
RM-89
RM-90
RM-91
RM-92
RM-93
RM-94
RM-95
RM-96
RM-97
RM-98
RM-99
RM-100
RM-101
RM-102
RM-103
RM-104
RM-105
RM-106
RM-107
RM-108
RM-109
RM-110
RM-111
RM-112
RM-113
RM-114
RM-115
RM-116
RM-117
RM-118
RM-119
RM-120
RM-121
RM-122
RM-123
RM-124
RM-125
RM-126
RM-127
RM-128
RM-129
RM-130
RM-131
RM-132
RM-133
RM-134
RM-135
RM-136
RM-137
RM-138
RM-139
RM-140
RM-141
RM-142
RM-143
RM-144
RM-145
RM-146
RM-147
RM-148
RM-149
RM-150
RM-151
RM-152
RM-153
RM-154
RM-155
RM-156
RM-157
RM-158
RM-159
RM-160
RM-161
RM-162
RM-163
RM-164
RM-165
RM-166
RM-167
RM-168
RM-169
RM-170
RM-171
RM-172
RM-173
RM-174
RM-175
RM-176
RM-177
RM-178
RM-179
RM-180
RM-181
RM-182
RM-183
In a preferred embodiment, the mixtures according to the invention comprise one or more polymerizable compounds, preferably selected from the polymerizable compounds of the formulae RM-1 to RM-182. Of these, compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-58, RM-64, RM-74, RM-76, RM-88, RM-91, RM-102, RM-103, RM-109, RM-116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-140, RM-142, RM-143, RM-145, RM-146, RM-147, RM-149, RM-156 to RM-163, RM-169, RM-170 and RM-171 to RM-183 are particularly preferred.
In a preferred embodiment, the LC media, SA-VA and SA-FFS displays according to the present invention comprise one or more SA additives selected from formulae SA-1 to SA-48, preferably from formulae SA-14 to SA-48, very preferably from formulae SA-20 to SA-34 and SA-44, in combination with one or more RMs.
The following examples explain the present invention without restricting it. However, they show the person skilled in the art preferred mixture concepts with compounds preferably to be employed and the respective concentrations thereof and combinations thereof with one another. In addition, the examples illustrate which properties and property combinations are accessible.
In addition, the following abbreviations and symbols are used:
Unless explicitly noted otherwise, all concentrations in the present application are quoted in percent by weight and relate to the corresponding mixture as a whole, comprising all solid or liquid-crystalline components, without solvents.
Unless explicitly noted otherwise, all temperature values indicated in the present application, such as, for example, for the melting point T (C,N), the transition from the smectic(S) to the nematic (N) phase T (S,N) and the clearing point T (N,I), are quoted in degrees Celsius (C). M.p. denotes melting point, cl.p.=clearing point. Furthermore, C=crystalline state, N=nematic phase, S=smectic phase and I=isotropic phase. The data between these symbols represent the transition temperatures.
All physical properties are and have been determined in accordance with “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, Status November 1997, Merck KGaA, Germany, and apply for a temperature of 20° C., and Δn is determined at 589 nm and Δε at 1 KHz, unless explicitly indicated otherwise in each case.
The term “threshold voltage” for the present invention relates to the capacitive threshold (V0), also known as the Freedericks threshold, unless explicitly indicated otherwise. In the examples, the optical threshold may also, as generally usual, be quoted for 10% relative contrast (V10).
Unless stated otherwise, the process of polymerizing the polymerizable compounds in the PSA displays as described above and below is carried out at a temperature where the LC medium exhibits a liquid crystal phase, preferably a nematic phase, and most preferably is carried out at room temperature.
Unless stated otherwise, methods of preparing test cells and measuring their electrooptical and other properties are carried out by the methods as described hereinafter or in analogy thereto.
A PSVA display or PSVA test cell used for photopolymerization and measurement of the tilt angles etc. consists of two plane-parallel glass outer plates at a separation of 3-4 μm unless stated otherwise, each of which has on the inside an electrode layer and a polyimide alignment layer on top, where the two polyimide layers are rubbed antiparallel to one another and effect a homeotropic edge alignment of the liquid-crystal molecules. The SAVA display or test cell has the same structure but wherein one or both polyimide layers are omitted.
The polymerizable compounds are polymerized in the display or test cell by irradiation with UV light of defined intensity for a prespecified time, with a voltage simultaneously being applied to the display (usually 10 V to 30 V alternating current, 1 kHz).
The tilt angle is determined using the Mueller Matrix Polarimeter “AxoScan” from Axometrics. A low value (i.e. a large deviation from the 90° angle) corresponds to a large tilt here.
Unless stated otherwise, the term “tilt angle” means the angle between the LC director and the substrate, and “LC director” means in a layer of LC molecules with uniform orientation the preferred orientation direction of the optical main axis of the LC molecules, which corresponds, in case of calamitic, uniaxially positive birefringent LC molecules, to their molecular long axis.
The nematic LC host mixture NC1 is formulated as follows:
The mixture NC1 does not contain a compound of formula L1 or L2.
The chiral nematic LC host mixture CCh1 is formulated by adding 0.91% of the chiral dopant S-4011 to 99.09% of the host mixture NC1.
The polymerizable LC mixture PC1 is formulated as follows:
The nematic LC host mixture NC2 is formulated as follows:
The mixture NC2 does not contain a compound of formula L1 or L2.
The chiral nematic LC host mixture CCh2 is formulated by adding 0.89% of the chiral dopant S-4011 to 99.11% of the host mixture NC2.
The polymerizable LC mixture PC2 is formulated as follows:
The nematic LC host mixture N1 is formulated as follows:
The mixture N1 contains the compound CLP-3-T of formula L1.
The chiral nematic LC host mixture Ch1 is formulated by adding 0.9% of the chiral dopant S-4011 to 99.1% of the host mixture N1.
The polymerizable LC mixture P1 is formulated as follows:
The nematic LC host mixture N2 is formulated as follows:
The mixture N2 contains the compound CLP-V-1 of formula L2.
The chiral nematic LC host mixture Ch2 is formulated by adding 0.9% of the chiral dopant S-4011 to 99.1% of the host mixture N2.
The polymerizable LC mixture P2 is formulated as follows:
The VHR of the polymerizable mixtures of Comparison Examples 1 and 2 and Examples 1 and 2 is measured after the PSA process and after ageing. The physical properties and the VHR of the polymerizable mixtures are summarized in Table 1 below.
It can be seen that the polymerizable mixtures P1 and P2 according to the present invention, which contain a compound of formula L1 or L2, show significantly better VHR than the polymerizable mixtures PC1 and PC2 without these compounds, while maintaining the desired values of other critical properties like dielectric anisotropy, birefringence, low viscosity and low value of γ1/K11.
The nematic LC host mixture N3 is formulated as follows:
The mixture N3 contains the compound CLP-V-1 of formula L2.
The polymerizable LC mixture P3 is formulated as follows:
The nematic LC host mixture N4 is formulated as follows:
The mixture N4 contains the compound CLP-V-1 of formula L2.
The polymerizable LC mixture P4 is formulated as follows:
The nematic LC host mixture N5 is formulated as follows:
The mixture N5 contains the compound CLP-V-1 of formula L2.
The polymerizable LC mixture P5 is formulated as follows:
The polymerizable LC mixture P6 is formulated as follows:
The polymerizable LC mixture P7 is formulated as follows:
The polymerizable LC mixture P8 is formulated as follows:
The polymerizable LC mixture P9 is formulated as follows:
The polymerizable LC mixture P10 is formulated as follows:
The polymerizable LC mixture P11 is formulated as follows:
The polymerizable LC mixture P12 is formulated as follows:
The polymerizable LC mixture P13 is formulated as follows:
The polymerizable LC mixture P14 is formulated as follows:
The polymerizable LC mixture P15 is formulated as follows:
The polymerizable LC mixture P15 is formulated as follows:
The polymerizable LC mixture P17 is formulated as follows:
The polymerizable LC mixture P18 is formulated as follows:
The polymerizable LC mixture P19 is formulated as follows:
The polymerizable LC mixture P20 is formulated as follows:
The polymerizable LC mixture P21 is formulated as follows:
The polymerizable LC mixture P22 is formulated as follows:
The polymerizable LC mixture P23 is formulated as follows:
The polymerizable LC mixture P24 is formulated as follows:
The polymerizable LC mixture P25 is formulated as follows:
The polymerizable LC mixture P26 is formulated as follows:
The polymerizable LC mixture P27 is formulated as follows:
The polymerizable LC mixture P28 is formulated as follows:
The polymerizable LC mixture P29 is formulated as follows:
The polymerizable LC mixture P30 is formulated as follows:
The polymerizable LC mixture P31 is formulated as follows:
The polymerizable LC mixture P32 is formulated as follows:
The polymerizable LC mixture P33 is formulated as follows:
The polymerizable LC mixture P34 is formulated as follows:
The polymerizable LC mixture P35 is formulated as follows:
The polymerizable LC mixture P36 is formulated as follows:
The polymerizable LC mixture P37 is formulated as follows:
The polymerizable LC mixture P38 is formulated as follows:
The polymerizable LC mixture P39 is formulated as follows:
The polymerizable LC mixture P40 is formulated as follows:
The polymerizable LC mixture P41 is formulated as follows:
The polymerizable LC mixture P42 is formulated as follows:
The nematic LC host mixture N6 is formulated as follows:
The mixture N6 contains the compound CLG-3-F of formula L1.
The polymerizable LC mixture P43 is formulated as follows:
The polymerizable LC mixture P44 is formulated as follows:
The polymerizable LC mixture P45 is formulated as follows:
The polymerizable LC mixture P46 is formulated as follows:
The polymerizable LC mixture P47 is formulated as follows:
The polymerizable LC mixture P48 is formulated as follows:
The polymerizable LC mixture P49 is formulated as follows:
| Number | Date | Country | Kind |
|---|---|---|---|
| 23218969 | Dec 2023 | EP | regional |
