Polymerizable liquid crystal media and polymerized liquid crystal films

Abstract

The present invention relates to polymerizable LC media comprising one or more di-or multi-reactive mesogenic compounds, one or more chiral compounds having an (s)-configuration, one or more chiral compounds having an (R)-configuration, where at least one chiral compound comprises a photoisomerizable group. Furthermore, the invention relates to a process for the preparation thereof, to polymer membranes obtainable from the corresponding polymerizable LC media, and to a process for the preparation of such polymer membranes. These polymer films can be used, for example, to adjust the optical properties of liquid crystal displays (LCDs), to improve light utilization efficiency, or to ensure the anti-reflection and visibility of organic light emitting devices (OLEDs), even for the purposes of AV / VR. The invention therefore also relates to the use of such a polymer film and said polymerizable LC medium in optical, electro-optical, decorative or security applications, as well as to corresponding devices.

Description

Technical Field

[0001] The present invention relates to a polymerizable LC medium comprising one or more direactive or polyreactive mesogenic compounds, one or more chiral compounds having (s)-configuration, one or more chiral compounds having (R)-configuration, wherein at least one chiral compound comprises a photoisomerizable group. In addition, the present invention also relates to a method for preparing the same, a polymer film obtainable from the corresponding polymerizable LC medium, and a method for preparing such a polymer film. These polymer films can be used, for example, to adjust the optical properties of a liquid crystal display (LCD), improve light utilization efficiency, or ensure antireflection and visibility of an organic light emitting device (OLED), and even for AV / VR purposes. Therefore, the present invention also relates to the use of such a polymer film and the polymerizable LC medium in optical, electro-optical, decorative or security applications, and the corresponding devices.

[0002] Background and Prior Art

[0003] OLED displays are built with a metal cathode that has a high reflectivity, acting like a mirror. It is important that the viewer only sees the light emitted by the OLED, and not the incident light that reflects off the display. To achieve this, an anti-reflective layer is needed in the display.

[0004] Typically, a circular polarizer is employed to optically isolate the incident light and eliminate reflections. A circular polarizer consists of a linear polarizer and a quarter-wave retarder. To prevent any reflected light from leaving the system, the quarter-wave plate (QWP) must have an optical retardation that precisely matches one-quarter of the wavelength of the incident light. Ideally, the QWP should be achromatic, so it performs equally well for all visible wavelengths.

[0005] Standard transparent materials have positive optical dispersion, i.e. the refractive index decreases as the wavelength increases. RM films with standard optical dispersion produce a QWP that converts linearly polarized input light into perfect circularly polarized light and vice versa only for a single wavelength. All other wavelengths will be converted into non-ideal elliptical polarization states, where a portion of the light will not be absorbed by the polarizer after reflection and transmitted to the viewer. This results in poor anti-reflection and the screen may look purple instead of black.

[0006] In order to produce an achromatic QWP, the retarder must have opposite (also called negative) optical dispersion, ie, the refractive index increases with increasing wavelength.

[0007] One way to make a QWP with opposite optical dispersion is to combine a half-wave plate (HWP) with positive optical dispersion with a QWP with positive optical dispersion. The two retarders must be laminated in such a way that the directors are perpendicular to each other. The disadvantage of this solution is the increased process cost due to having to apply two separate coatings and then laminate them together. The yield is also reduced due to the lamination cutting process.

[0008] Optical films based on polymerizable liquid crystal materials typically exhibit wavelength-dependent retardation. In this regard, three main optical behaviors are known:

[0009] i) "Normal" or "positive" optical dispersion, such as described in EP 0 940 707 B1

[0010] ii) "opposite" or "negative" optical dispersion, such as described in WO 2016 / 020035 A1, and

[0011] iii) "Flat" optical dispersion, as described, for example, in WO 2009 / 058396 A1.

[0012] For example, polymerizable liquid crystal materials with flat or negative dispersion can be prepared by adding at least one ordinary refractive index (n o ) is higher than the extraordinary refractive index (n e ) components. For this reason, it is usually necessary that highly conjugated substituents are located in orthogonal positions to the long axis of the molecule. These materials absorb part of the UV dose when curing the optical film, resulting in a poor degree of cure and poor thermal durability of the cured film. In addition, the molecular blocks are easily oxidized in the presence of oxygen at high temperatures. The same applies to high birefringence formulations containing highly conjugated reactive mesogens, which reduce the thermal durability of the cured film and are generally prone to yellowing.

[0013] The prior art also discloses polymerizable compounds with H-shape or T-shape for birefringent polymer films with negative optical dispersion. For example, WO 2008 / 119427 A1 describes a birefringent polymer film with negative optical dispersion obtainable from a polymerizable LC medium comprising a compound with H-shape as a negative dispersion component.

[0014] Suitable compounds having a T-shape and corresponding birefringent polymer films having negative optical dispersion are disclosed, for example, in US2015175564, WO 17079867 A1, WO16104317 A, US2015277007A1 or WO 16171041A1, and in particular compounds represented by formulas 1 to 5 of US 2015175564A1, compounds represented by formulas (I-1) to (I-5), (I-8), (I-14), (I-16) to (I-36), (I-41), (I-54) to (I-65), (I-75) to (I-80), (I-82), (I-83), (I-86) to (I-97) and (I-121) to (I-125) of WO 17 / 079867A1, Compounds represented by formulae (A12-16) to (A12-18), (A14-1) to (A14-3) and (A141-1) to (A143-2) of US 2015 / 0277007A1, and compounds represented by formulae (2-A) to (2-D), (3-A) to (3-D), (4-A) to (4-D), (5-A) to (5-D), (7-A) to (7-D), (8-A) to (8-D), (9-A) to (9-D), (11-B) to (11-D), (12-b) to (12-D), (13-B) to (13-D), (22-B) to (22-D), (25-A) to (25-D) of US 2015 / 0277007A1 -B) to (25-D), (40-A) to (40-D), (41-A) to (41-D), (42-A) to (42-D), (43-A) to (43-D), (44-A) to (44-D), (50-A) to (50-D), (52-A) to (52-D), (54-A) to (54-D), (55-A) to (55-D) or (56-A) to (56-D), compounds represented by formula (A) to (E) of WO 16171041 A1.

[0015] However, the bulk properties of negative dispersion compounds according to the prior art are often difficult to align or give formulations with narrow annealing temperature process windows, which is not conducive to large-scale production. In addition, the polymer films are often weak and have poor heat resistance. However, the main disadvantage is that the synthesis costs of T-shaped and H-shaped materials are much higher than those of standard LC molecules due to the increase in synthesis steps. A cheaper alternative than typical opposite dispersion films would be competitive in a wider market, especially for OLED TVs.

[0016] In this regard, US2016187554 A1 proposes an optical film that exhibits so-called reverse wavelength dispersion while forming a single thin layer by controlling the alignment state of the liquid crystal compound in the liquid crystal layer. These films can be used, for example, to adjust the optical properties of a liquid crystal display (LCD), improve light utilization efficiency, or ensure the anti-reflection and visibility of an organic light-emitting device (OLED). In addition, the film as described above can be used to generate a stereoscopic image, or to improve the quality of a stereoscopic image.

[0017] However, there is still a need for new and improved polymerizable liquid crystal materials or polymer films produced therefrom which do not exhibit the disadvantages of the prior art materials or, if they do, exhibit them only to a lesser extent.

[0018] The polymerizable LC media comprising them for film preparation should exhibit good thermal properties, in particular a moderate melting point, good solubility in LC hosts and organic solvents and a reasonable extrapolated clearing point, and should also exhibit excellent optical properties.

[0019] Advantageously, the polymerisable LC material should preferably be suitable for the preparation of different polymer films and should, in particular simultaneously,

[0020] - show favorable adhesion to the substrate,

[0021] -Highly transparent to VIS-light,

[0022] - show a yellow coloration (yellowing) that decreases over time,

[0023] -Exhibits high birefringence to reduce film thickness,

[0024] - exhibit favorable high temperature stability or durability, and in addition

[0025] - The polymer membranes should be inexpensive to produce by compatible, well-known mass production methods.

[0026] Other objects of the present invention will be immediately apparent to those skilled in the art from the following detailed description.

[0027] Surprisingly, the inventors of the present invention have found that one or more, preferably all of the above requirements can be met, preferably simultaneously, by using a polymerisable LC medium as disclosed and claimed hereinafter. Summary of the invention

[0028] The present invention relates to a polymerisable LC medium comprising one or more di- or polyreactive mesogenic compounds, one or more chiral compounds with (S) configuration, one or more chiral compounds with (R) configuration, wherein at least one chiral compound comprises a photoisomerisable group.

[0029] The present invention also relates to a process for the production of a polymerisable LC medium as described above and below.

[0030] The present invention also relates to the use of polymerisable LC media as described above and below in optical, electronic and electro-optical elements and devices, preferably in optical films, retarders or compensators with flat optical dispersion.

[0031] The present invention relates in particular to a process for producing a polymer film as described above and below.

[0032] The present invention further relates to a birefringent polymer film obtainable or obtained by polymerizing a polymerizable LC medium as described above and below, preferably in its LC phase in an oriented state in the form of a thin film.

[0033] The present invention particularly relates to a polymer film as described above and below, which is an achromatic QWP.

[0034] The invention further relates in particular to the use of a polymer film as described above and below in an optical component.

[0035] The present invention also relates to such an optical, electronic or electro-optical component or device comprising a polymerisable LC medium or a polymer film as described above and below.

[0036] The devices include, but are not limited to, electro-optical displays (e.g., OLEDs and LCDs), nonlinear optical (NLO) devices, optical information storage devices, electronic devices, electroluminescent displays, organic photovoltaic (OPV) devices, lighting devices, sensor devices, electrophotographic recording devices, organic memory devices, or devices for AR / VR applications.

[0037] Terms and Definitions

[0038] As used herein, the term "polymer" will be understood to refer to a molecule comprising a backbone of one or more different types of repeating units (the smallest building blocks of a molecule), and includes the well-known terms "oligomer", "copolymer", "homopolymer", etc. In addition, it should be understood that the term polymer includes, in addition to the polymer itself, residues from initiators, catalysts, and other elements accompanying the synthesis of such polymers, wherein such residues are understood not to be covalently incorporated therein. In addition, such residues and other elements, although generally removed during post-polymerization purification, are generally mixed or blended with the polymer so that they are generally retained in the polymer when the polymer is transferred between containers or between solvents or dispersion media.

[0039] The term "(meth)acrylic polymer" as used in the present invention includes polymers obtainable from acrylic monomers, polymers obtainable from methacrylic monomers, and corresponding copolymers obtainable from mixtures of such monomers.

[0040] The term "polymerization" refers to a chemical process of forming a polymer by bonding together a plurality of polymerizable groups or polymer precursors (polymerizable compounds) containing such polymerizable groups.

[0041] The term "film" or "layer" includes rigid or flexible, self-supporting or free-standing films having mechanical stability, as well as coatings or layers on a supporting substrate or between two substrates.

[0042] The term "liquid crystal or mesogenic compound" refers to a compound comprising one or more rod-shaped (rod or plate / slat-shaped) or disc-shaped (disc-shaped) mesogenic groups. The term "mesogenic group" refers to a group having the ability to induce liquid crystal (LC) phase behavior. Compounds comprising mesogenic groups do not necessarily have to exhibit LC mesophases themselves. They can also exhibit LC phase behavior only in a mixture with other compounds, or when the mesogenic compound or material or a mixture thereof is polymerized. For simplicity, the term "liquid crystal" is used hereinafter for mesogenic materials and LC materials. For an overview of definitions, see C. Tschierske, G. Pelzl and S. Diele, Angew. Chem. 2004, 116, 6340-6368.

[0043] The rod-like mesogenic group generally comprises a mesogenic core composed of one or more aromatic or non-aromatic cyclic groups connected to each other directly or via a connecting group, optionally comprising an end group attached to the end of the mesogenic core, and optionally comprising one or more side groups attached to the long side of the mesogenic core, wherein these end groups and side groups are generally selected from, for example, carbon groups (carbyl) or hydrocarbon groups, polar groups (such as halogen, nitro, hydroxyl, etc.) or polymerizable groups.

[0044] The term "reactive mesogen" (RM) refers to a polymerizable mesogenic or liquid crystalline compound.

[0045] A polymerizable compound having one polymerizable group is also referred to as a "monoreactive" compound, a compound having two polymerizable groups is also referred to as a "direactive" compound, and a compound having more than two polymerizable groups is also referred to as a "polyreactive" compound. A compound that does not contain a polymerizable group is also referred to as a "non-reactive" compound.

[0046] The term "non-mesogenic compound or material" refers to a compound or material that does not contain a mesogenic group as defined above.

[0047] Visible light is electromagnetic radiation having a wavelength in the range of about 400 nm to about 740 nm. Ultraviolet (UV) light is electromagnetic radiation having a wavelength in the range of about 200 nm to about 450 nm.

[0048] According to the present application, the term "linearly polarized light" refers to light that is at least partially linearly polarized. Preferably, the aligning light is linearly polarized with a degree of polarization greater than 5:1. The choice of wavelength, intensity and energy of the linearly polarized light depends on the photosensitivity of the photoalignable material. Typically, the wavelength is in the UV-A, UV-B and / or UV-C range or in the visible range. Preferably, the linearly polarized light comprises light with a wavelength of less than 450 nm, more preferably less than 420 nm, while the linearly polarized light preferably comprises light with a wavelength greater than 280 nm, preferably greater than 320 nm, more preferably greater than 350 nm.

[0049] Irradiance (E e ) or radiant power is defined as the electromagnetic radiation power (dθ) per unit area (dA) incident on a surface:

[0050] E e =dθ / dA.

[0051] Radiation exposure or radiation dose (H e ) is the irradiance or radiant power (E) per time (t) e ):

[0052] H e =E e ·t.

[0053] All temperatures, such as the melting point of the liquid crystal T(C,N) or T(C,S), the transition from the smectic phase (S) to the nematic phase (N) T(S,N) and the clearing point T(N,I) are given in degrees Celsius. All temperature differences are given as a difference in degrees.

[0054] The term "clearing point" refers to the temperature at which the transition between the intermediate phase having the highest temperature range and the isotropic phase occurs.

[0055] At the molecular level, the birefringence of liquid crystals depends on the anisotropy of polarizability "Polarizability" refers to the ease with which the electron distribution in an atom or molecule can be deformed. Polarizability increases as the number of electrons increases and the electron cloud spreads out. Polarizability can be measured using, for example, Jap. J. Appl. Phys. 42 , (2003) p.3463.

[0056] The "optical retardation" of a layer of liquid crystal or birefringent material at a given wavelength R(λ) (in nm) is defined as the product of the birefringence Δn(λ) at that wavelength and the layer thickness d (in nm) according to the following equation:

[0057] R(λ)=Δn(λ)·d

[0058] Optical retardation R is the difference in optical path lengths traveled by S-polarized and P-polarized light when passing through a birefringent material, expressed in nanometers. "On-axis" retardation refers to the retardation at normal incidence at the sample surface.

[0059] The term "negative (optical) dispersion" means that the birefringence of a liquid crystal material or layer exhibits opposite birefringence dispersion, wherein the magnitude of the birefringence (Δn) increases with increasing wavelength (λ), i.e., |Δn(450)|<|Δn(550)|, or Δn(450) / Δn(550)<1, wherein Δn(450) and Δn(550) are the birefringence of the material measured at wavelengths of 450 nm and 550 nm, respectively. In contrast, "positive (optical) dispersion" refers to a material or layer having |Δn(450)|>|Δn(550)| or Δn(450) / Δn(550)>1. See also, for example, A. Uchiyama, T. Yatabe "Control of Wavelength Dispersionof Birefringence for Oriented Copolycarbonate Films Containing Positive and Negative Birefringent Units". J. Appl. Phys. Vol. 42 pp 6941-6945 (2003). "Flat (optical) dispersion" refers to a material or layer having |Δn(450)|>|Δn(550)| or Δn(450) / Δn(550)≈1.

[0060] Since the retardation of light at a given wavelength is defined as the product of the birefringence and the layer thickness [R(λ)=Δn(λ)·d] as described above, the optical dispersion can be expressed as the ratio Δn(450) / Δn(550) as "birefringence dispersion", or as the ratio R(450) / R(550) as "retardation dispersion", where R(450) and R(550) are the retardations of the material measured at wavelengths of 450 nm and 550 nm, respectively. Since the layer thickness d does not vary with wavelength, R(450) / R(550) is equal to Δn(450) / Δn(550). Thus, a material or layer with negative or opposite dispersion has R(450) / R(550)<1 or |R(450)|<|R(550)|, a material or layer with positive or normal dispersion has R(450) / R(550)>1 or |R(450)|>|R(550)|, and a material or layer with flat dispersion has R(450) / R(550)≈1 or |R(450)|≈|R(550)|.

[0061] In the present invention, unless otherwise specified, "optical dispersion" refers to retardation dispersion, that is, the ratio R(450) / R(550).

[0062] The term "high dispersion" means that the absolute value of the dispersion shows a large deviation from 1, while the term "low dispersion" means that the absolute value of the dispersion shows a small deviation from 1. Thus, for example, "high negative dispersion" means that the dispersion value is significantly less than 1, and "low negative dispersion" means that the dispersion value is only slightly less than 1.

[0063] The retardation (R(λ)) of a material can be measured using a spectroscopic ellipsometer, such as the M2000 spectroscopic ellipsometer manufactured by JA Woollam Co. This instrument is capable of measuring the nanoscale optical retardation of birefringent samples, such as quartz, over a range of wavelengths, typically from 370nm to 2000nm. From this data, the dispersion of the material (R(450) / R(550) or Δn(450) / Δn(550)) can be calculated.

[0064] The method for making these measurements is presented in "Spectroscopic Ellipsometry, Part 1 - Theory and Fundamentals, Part 2 - Practical Examples and Part 3 - measurements" by N. Singh in the National Physics Laboratory (London, UK) in October 2006. The method is based on the Retardation Measurement (RetMeas) Manual (2002) and Guide to WVASE (2002) published by JA Woolam Co. Inc (Lincoln, NE, USA) ( W oollam V ariable A ngle S pectroscopic E Unless otherwise stated, this method is used to determine the retardation of the materials, films, and devices described in this invention.

[0065] The birefringence Δn is defined as follows

[0066] Δn=n e -n o

[0067] Where n e is the extraordinary refractive index and n o is the ordinary refractive index, and the average effective refractive index n av. Given by the following equation:

[0068] n av. =((2n o 2 +n e 2 ) / 3) 1 / 2

[0069] Average effective refractive index n av. and the ordinary refractive index n o This can be measured using an Abbe refractometer. Δn can then be calculated from the above equation.

[0070] The polymerizable LC media according to the invention can be prepared, for example, by doping the media with chiral compounds having a high twisting power. The pitch p of the induced cholesteric helix is ​​then given by the concentration c of the chiral compound and the helical twisting power HTP according to the following equation:

[0071] p=(HTP c) -1

[0072] The total HTP of chiral compounds with the same configuration (HTP total ) roughly conforms to the following equation:

[0073] HTP total =∑ i c i HTP i

[0074] where c i is the concentration of each individual chiral compound, HTP i is the helical twisting force of each individual chiral compound.

[0075] HTP of all chiral compounds in a mixture of different configurations (|HTP Δ |) roughly conforms to the following equation:

[0076] |HTP Δ |=(∑ s c s HTP s )-(∑ r c r HTP r )

[0077] where c s is the concentration of each individual chiral compound with S configuration, HTP s is the helical twisting force of each individual chiral compound with S configuration, where c r is the concentration of each individual chiral compound with R configuration, HTP R is the helical twisting force of each individual chiral compound with R configuration.

[0078] According to the present invention, a photoreactive group (also called a photoisomerization group) is a functional group of a molecule which, when irradiated with light of a suitable wavelength that the molecule can absorb, causes a change in the geometric configuration of the molecule, i.e. isomerization (photoisomerization), by bond rotation, skeleton rearrangement, or atom or group transfer, or by dimerization.

[0079] According to the present invention, a photoreactive compound (also referred to as a photoisomerizable compound) is a compound comprising one or more photoreactive groups (or photoisomerizable groups).

[0080] Examples of photoreactive groups are -C=C- double bonds and azo groups (-N=N-). Examples of molecular structures and substructures containing such photoreactive groups are stilbene, (1,2-difluoro-2-phenylvinyl)-benzene, cinnamate, 4-phenylbut-3-en-2-one, chalcone, coumarin, chromone, pentalenone and azobenzene.

[0081] The term "director" is known in the prior art and refers to the preferred orientation direction of the long molecular axis (in the case of rod-shaped compounds) or the short molecular axis (in the case of discotic compounds) of the liquid crystal or RM molecules. In the case of uniaxial ordering of such anisotropic molecules, the director is the axis of anisotropy.

[0082] Unless explicitly stated otherwise, all physical properties have been measured according to or according to “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, Status November 1997, Merck KGaA, Germany, and are given for a temperature of 20° C. The optical anisotropy (Δn) is measured at a wavelength of 589.3 nm.

[0083] In case of doubt, the definitions as given in C. Tschierske, G. Pelzl and S. Diele, Angew. Chem. 2004, 116, 6340-6368 shall apply.

[0084] Unless expressly stated otherwise, in the given general formulae, the following terms have the following meanings:

[0085] "Carbonyl" means a monovalent or multivalent organic group containing at least one carbon atom, which contains no other atoms (such as -C≡C-) or optionally contains one or more other atoms, such as N, O, S, P, Si, Se, As, Te or Ge (e.g., carbonyl, etc.). "Alkyl" means a carbon group, which additionally contains one or more H atoms and optionally one or more heteroatoms, such as N, O, S, P, Si, Se, As, Te or Ge.

[0086] The carbyl or hydrocarbon group may be a saturated or unsaturated group. An unsaturated group is, for example, an aryl, an alkenyl or an alkynyl group. A carbyl or hydrocarbon group having more than 3 C atoms may be straight chain, branched and / or cyclic and may contain spiro-connected or fused rings.

[0087] Preferred carbyl and hydrocarbyl groups are optionally substituted alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy groups having 1 to 40 C atoms, preferably 1 to 25 C atoms, particularly preferably 1 to 18 C atoms, optionally substituted aryl or aryloxy groups having 6 to 40 C atoms, preferably 6 to 25 C atoms, or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy groups having 6 to 40 C atoms, preferably 6 to 25 C atoms.

[0088] Other preferred carbon and hydrocarbon groups are C 1 -C 40 Alkyl, C 2 -C 40 Alkenyl, C 2 -C 40 Alkynyl, C 3 -C 40 Allyl, C 4 -C 40 Alkyldiene, C 4 -C 40 Polyene, C 6 -C 40 Aryl, C 6 -C 40 Alkyl aryl, C 6 -C 40 Arylalkyl, C 6 -C 40 Alkyl aryloxy, C 6 -C 40 Arylalkyloxy, C 2 -C 40 Heteroaryl, C 4 -C 40 Cycloalkyl, C 4 -C 40 Cycloalkenyl, etc. Preferably C 1 -C 22 Alkyl, C 2 -C 22 Alkenyl, C 2 -C 22 Alkynyl, C 3 -C 22 Allyl, C 4 -C 22 Alkyldiene, C 6 -C 12 Aryl, C 6 -C 20 Arylalkyl and C 2 -C 20 Heteroaryl.

[0089] Other preferred carbon and hydrocarbon radicals are straight-chain, branched or cyclic alkyl radicals having 1 to 40 C atoms, preferably 1 to 25 C atoms, more preferably 1 to 12 C atoms, which are unsubstituted or mono- or polysubstituted by F, Cl, Br, I or CN, and in which one or more non-adjacent CH 2 The groups may each be independently -C(R x )=C(R x )-,-C≡C-,-N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other.

[0090] In the above, R x Preferably it is H, halogen, a straight-chain, branched or cyclic alkyl chain having 1 to 25 C atoms, wherein furthermore one or more non-adjacent C atoms may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and wherein one or more H atoms may be replaced by fluorine, optionally substituted aryl or aryloxy having 6 to 40 C atoms or optionally substituted heteroaryl or heteroaryloxy having 2 to 40 C atoms.

[0091] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, n-hexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, and the like.

[0092] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl and the like.

[0093] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl and the like.

[0094] Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, 2-methylbutoxy, n-pentoxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy and the like.

[0095] Preferred amino groups include dimethylamino, methylamino, methylphenylamino, phenylamino and the like.

[0096] Aryl and heteroaryl groups may be monocyclic or polycyclic, i.e. they may have one ring (such as phenyl) or two or more rings, which may also be fused (such as naphthyl) or covalently linked (such as biphenyl), or contain a combination of fused and linked rings. Heteroaryl groups contain one or more heteroatoms, preferably selected from O, N, S and Se.

[0097] Preferred are monocyclic, bicyclic or tricyclic aryl groups with 6 to 25 C atoms and monocyclic, bicyclic or tricyclic heteroaryl groups with 2 to 25 C atoms, which optionally contain fused rings and which are optionally substituted. In addition, preferred are 5-, 6- or 7-membered aryl and heteroaryl groups, in which in addition one or more CH groups may be replaced by N, S or O in such a way that O atoms and / or S atoms are not directly connected to one another.

[0098] Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1':3',1"]-terphenyl-2'-yl, naphthalene, anthracene, binaphthyl, phenanthrene, pyrene, dihydropyrene, Perylene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene, and the like.

[0099] Preferred heteroaryl groups are, for example, 5-membered rings, such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 6-membered rings, such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine or fused groups, such as indole, isoindole , indolizine, indazole, benzimidazole, benzotriazole, purine, naphthimidazole, phenanthimidazole, pyridimidazole, pyrazimidazole, quinoxalineimidazole, benzoxazole, naphthimidazole, anthraxazole, phenanthimidazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, Benzo-7,8-quinoline, benzisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiadiazolethiophene, or a combination of these groups. The heteroaryl group may also be substituted by an alkyl, alkoxy, sulfanyl, fluorine, fluoroalkyl or other aryl or heteroaryl groups.

[0100] (Non-aromatic) alicyclic groups and heterocyclic groups include both saturated rings, i.e. those containing only single bonds, and partially unsaturated rings, i.e. those which may also contain multiple bonds. The heterocyclic ring contains one or more heteroatoms, preferably selected from Si, O, N, S and Se.

[0101] (Non-aromatic) alicyclic and heterocyclic groups may be monocyclic, i.e. contain only one ring (e.g. cyclohexane), or polycyclic, i.e. contain multiple rings (e.g. decalin or bicyclooctane). Saturated groups are preferred. In addition, mono-, bi- or tricyclic groups with 3 to 25 C atoms are preferred, which optionally contain fused rings and which are optionally substituted. Further preferred are 5-, 6-, 7- or 8-membered carbocyclic groups, in which in addition, one or more C atoms may be replaced by Si and / or one or more CH groups may be replaced by N and / or one or more non-adjacent CH 2 The group may be substituted by -O- and / or -S-.

[0102] Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups, such as cyclopentane, tetrahydrofuran, tetrahydrothiophene, pyrrolidine; 6-membered groups, such as cyclohexane, silinane, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine; 7-membered groups, such as cycloheptane; and condensed groups, such as tetralin, decalin, indane, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, octahydro-4,7-methanoindan-2,5-diyl.

[0103] The aryl, heteroaryl, (non-aromatic) alicyclic and heterocyclic groups optionally have one or more substituents, which are preferably selected from silyl, sulfonic acid, sulfonyl, formyl, amine, imine, nitrile, mercapto, nitro, halogen, C 1 -C 12 Alkyl, C 6 -C 12 Aryl, C 1 -C 12 Alkoxy, hydroxy or a combination of these groups.

[0104] Preferred substituents are, for example, solubility promoting groups, such as alkyl or alkoxy groups; electron withdrawing groups, such as fluorine, nitro or nitrile; or substituents used to increase the glass transition temperature (Tg) of the polymer, especially bulky groups, such as tert-butyl or optionally substituted aryl groups.

[0105] Preferred substituents (hereinafter also referred to as "L") are, for example, F, Cl, Br, I, -OH, -CN, -NO 2 , -NCO, -NCS, -OCN, -SCN, -C(=O)N(Rx ) 2 、-C(=O)Y x 、-C(=O)R x 、-C(=O)OR x 、-N(R x ) 2 , where R x has the meanings mentioned above, and the above Y x represents halogen; optionally substituted silyl; optionally substituted aryl or heteroaryl having 4 to 40, preferably 4 to 20 ring atoms; and straight-chain or branched alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, wherein one or more H atoms may be optionally replaced by F or Cl.

[0106] "Substituted silyl or aryl" preferably refers to substituted silyl or aryl groups with halogen, -CN, R y 、-OR y 、-CO-R y 、-CO-OR y 、-O-CO-R y OR-O-CO-OR y Substitution, where R y represents H, a linear, branched or cyclic alkyl chain having 1 to 12 C atoms.

[0107] In the formulae shown above and below, the substituted phenylene ring

[0108] Preferably

[0109]

[0110] wherein L has, at each occurrence, identically or differently, one of the meanings given above and below and is preferably F, Cl, CN, NO 2 , CH 3 , C 2 H 5 , C(CH 3 ) 3 、CH(CH 3 ) 2 , CH 2 CH(CH 3 )C 2 H 5 、OCH 3 , OC 2 H 5 、COCH 3 、COC 2 H 5 、COOCH3 、COOC 2 H 5 CF 3 、OCF 3 , OCHF 2 , OC 2 F 5 or P-Sp-, very preferably F, Cl, CN, CH 3 , C 2 H 5 、OCH 3 、COCH 3 、OCF 3 or P-Sp-, most preferably F, Cl, CH 3 、OCH 3 、COCH 3 or OCF 3 .

[0111] "Halogen" means F, Cl, Br or I, preferably F or Cl, more preferably F.

[0112] The "polymerizable group" (P) is preferably selected from groups comprising a C=C double bond or a C≡C triple bond, and groups suitable for ring-opening polymerization, such as, for example, an oxetanyl group or an epoxy group.

[0113] Preferably, the polymerizable group (P) is selected from CH 2 =CW 1 -COO-, CH 2 =CW 1 -CO-,

[0114] CH 2 =CW 2 -

[0115] (O) k3 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH 2 =CW 1 -CO-NH-, CH 3 -CH=CH-O-, (CH 2 =CH) 2 CH-OCO-, (CH 2 =CH-CH 2 ) 2 CH-OCO-, (CH 2 =CH) 2 CH-O-, (CH 2 =CH-CH 2 )2 N-, (CH 2 =CH-CH 2 ) 2 N-CO-, CH 2 =CW 1 -CO-NH-, CH 2 =CH-(COO) k1 -Phe-(O) k2 -, CH 2 =CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, where

[0116] W 1 Indicates H, F, Cl, CN, CF 3 , phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH 3 ,

[0117] W 2 represents H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl,

[0118] W 3 and W 4 Each independently of one another represents H, Cl or an alkyl radical having 1 to 5 C atoms, Phe represents 1,4-phenylene, which is optionally substituted by one or more radicals L as defined above but different from P-Sp, preferably, the preferred substituents L are F, Cl, CN, NO 2 , CH 3 , C 2 H 5 、OCH 3 , OC 2 H 5 、COCH 3 、COC 2 H 5 、COOCH 3 、COOC 2 H 5 CF 3 、OCF 3 , OCHF 2 , OC 2 F 5 , and phenyl, and

[0119] k 1 , k 2 and k 3 Each independently represents 0 or 1, k 3 Preferably represents 1, and k 4 is an integer from 1 to 10.

[0120] A particularly preferred polymerizable group P is CH 2 =CH-COO-, CH 2 =C(CH 3 )-COO-,CH 2 =CF-COO-, CH 2 =CH-, CH 2 =CH-O-, (CH 2 =CH) 2 CH-OCO-, (CH 2 =CH) 2 CH-O-, Where W 2 represents H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl.

[0121] Further preferred polymerizable groups (P) are vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetanyl and epoxy, most preferably acrylate or methacrylate, in particular acrylate.

[0122] Preferably, all polyreactive polymerizable compounds and subformulae thereof comprise one or more branching groups (polyreactive polymerizable groups) comprising two or more polymerizable groups P instead of one or more groups P-Sp-.

[0123] Suitable groups of this type and polymerizable compounds comprising them are described, for example, in US Pat. No. 7,060,200 B1 or US 2006 / 0172090 A1.

[0124] The polyreactive polymerizable group is preferably selected from the following formula

[0125] -X-alkyl-CHP x -CH 2 -CH 2 P y I * a

[0126] -X-alkyl-C(CH 2 P x )(CH 2 P y )-CH 2 P z I * b

[0127] -X-alkyl-CHP x CHP y -CH 2 P z I* c

[0128] -X-alkyl-C(CH 2 P x )(CH 2 P y )-C aa H 2aa+1 I * d

[0129] -X-alkyl-CHP x -CH 2 P y I * e

[0130] -X-alkyl-CHP x P y I * f

[0131] -X-alkyl-CP x P y -C aa H 2aa+1 I * g

[0132] -X-alkyl-C(CH 2 P v )(CH 2 P w )-CH 2 OCH 2 -C(CH 2 P x )(CH 2 Py)CH 2 P z I * h

[0133] -X-alkyl-CH((CH 2 ) aa P x )((CH 2 ) bb P y ) I * i

[0134] -X-alkyl-CHP x CHP y -C aa H 2aa+1 I * k

[0135] wherein

[0136] Alkyl represents a single bond or a straight-chain or branched alkylene group having 1 to 12 C atoms, wherein one or more non-adjacent CH 2 The groups may each be independently replaced by -C(R x )=C(R x )-,-C≡C-,-N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other, and further wherein one or more H atoms may be replaced by F, Cl or CN, wherein R x has one of the meanings mentioned above,

[0137] aa and bb each independently represents 0, 1, 2, 3, 4, 5 or 6,

[0138] X has one of the meanings indicated for X', and

[0139] P v To P z Each independently of the others has one of the meanings indicated above for P.

[0140] Preferred spacer groups Sp are selected from the formula Sp'-X', such that the group "P-Sp-" conforms to the formula "P-Sp'-X'-", wherein

[0141] Sp' denotes alkylene having 1 to 20, preferably 1 to 12 C atoms, which is optionally mono- or poly-substituted by F, Cl, Br, I or CN, and in which one or more non-adjacent CH 2 The groups can be independently replaced by -O-, -S-, -NH-, -NR xx -、-SiR xx R yy -, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, -NR xx -CO-O-, -O-CO-NR xx -、-NR xx -CO-NR yy -, -CH=CH- or -C≡C- in such a way that the O and / or S atoms are not directly connected to each other,

[0142] X' represents -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR xx -、-NR xx -CO-、-NR xx -CO-NR yy -、-OCH2 -、-CH 2 O-、-SCH 2 -、-CH 2 S-、-CF 2 O-、-OCF 2 -、-CF 2 S-, -SCF 2 -、-CF 2 CH 2 -、-CH 2 CF 2 -、-CF 2 CF 2 -, -CH=N-, -N=CH-, -N=N-, -CH=CR xx -、-CY xx =CY xx -, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond,

[0143] R xx and R yy each independently of one another represents H or an alkyl group having 1 to 12 C atoms, and

[0144] Y xx and Y yy Each independently of one another represents H, F, Cl or CN.

[0145] X' is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR xx -、-NR xx -CO-、-NR xx -CO-NR yy - or single key.

[0146] Typical spacer groups Sp' are, for example, -(CH 2 ) p1 -、-(CH 2 CH 2 O) q1 -CH 2 CH 2 -、-CH 2 CH 2 -S-CH 2 CH 2 -、-CH 2 CH 2 -NH-CH 2 CH 2 -or-(SiR xx R yy -O) p1-, wherein p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R xx and R yy has the meaning given above.

[0147] A particularly preferred group -X'-Sp'- is -(CH 2 ) p1 -,-O-(CH 2 ) p1 -,-OCO-(CH 2 ) p1 -,-OCOO-(CH 2 ) p1 -, where p1 is an integer from 1 to 12.

[0148] Particularly preferred radicals Sp′ are, for example, in each case straight-chain methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, vinylene, propenylene and butenylene.

[0149] For the present invention,

[0150]

[0151] represents trans-1,4-cyclohexylene, and

[0152]

[0153] It represents 1,4-phenylene.

[0154] For the purposes of the present invention, the group -COO-, -C(=O)O- or -CO 2 -Expression The ester group, and the groups -OCO-, -OC(=O)-, -O 2 C- or –OOC-expression Ester group.

[0155] All concentrations are expressed as weight percent (w / w) and are relative to the respective mixture as a whole, all temperatures are expressed in degrees Celsius and all temperature differences are expressed as differences in degrees.

[0156] Unless the context clearly indicates otherwise, as used herein, plural forms of the terms are to be understood as including the singular form and vice versa.

[0157] Throughout the description and claims of this specification, the words "include" and "contain" and variations of the words (such as "comprising" and "comprises") mean "including but not limited to", and are not intended to (and do not) exclude other components. On the other hand, the word "comprising" also encompasses but is not limited to the term "consisting of..."

[0158] Throughout the description and claims of this specification, the terms "obtainable" and "obtained" and variations of the terms mean "including but not limited to", and are not intended to (and do not) exclude other components. On the other hand, the term "obtainable" also encompasses but is not limited to the term "obtained". DETAILED DESCRIPTION OF THE INVENTION

[0160] Typically, when an opposite dispersion QWP is prepared from a polymer film comprising a polymerized RM or a polymerized RM mixture (RMM) (hereinafter also referred to as an "RM film"), the RM film or a portion of the RM film stack must have a director orientation perpendicular to the body, such as the HWP+QWP combination known in the above-mentioned prior art.

[0161] In contrast, the polymer film according to the present invention has a planar alignment, and by adding a small amount of a chiral dopant with a high twisting force, a helical twist is induced in the direction of the entire film thickness. As a result, a vertical director orientation can be provided in a single film using only positive dispersion materials. This makes the material cost low and improves market competitiveness.

[0162] Furthermore, the polymer films according to the invention show a biased pitch (or pitch gradient), i.e., wherein the chiral twist angle increases or decreases along the film thickness (i.e., in a direction perpendicular to the film plane). By using the materials and methods according to the invention, such structures have been achieved by applying low-intensity UV light.

[0163] The polymerisable LC medium according to the present invention preferably comprises

[0164] - a nematic RM host mixture comprising one or more di- or poly-reactive mesogenic compounds and optionally one or more mono-reactive mesophase compounds, and

[0165] a chiral component comprising one or more chiral compounds having the (S) configuration and one or more chiral compounds having the (R) configuration, wherein at least one chiral compound is photoreactive and preferably comprises a photoisomerizable group, and

[0166] -Optionally a photoinitiator.

[0167] Preferably, the method for preparing the polymer film according to the present invention requires only one additional production step compared to the method for preparing conventional planar alignment RM films. This additional step is low intensity UV exposure in air to induce photoisomerization of the chiral compound, and does not require an inert gas atmosphere or additional heating or cooling of the film.

[0168] In a preferred embodiment, the polymerisable LC medium comprises one or more di- or poly-reactive RMs, which are preferably selected from DRMs of the formula

[0169] P 1 -Sp 1 -MG-Sp 2 -P 2 DRM

[0170] in

[0171] P 1 and P 2 independently of one another represent a polymerizable group,

[0172] Sp 1 and Sp 2 are independently a spacer group or a single bond, and

[0173] MG is a rod-shaped mesogenic group, which is preferably selected from the formula MG

[0174] -(A 1 -Z 1 ) n -A 2 -MG

[0175] in

[0176] A 1 and A 2 represents, in the case of multiple occurrences, independently of one another, an aromatic or cycloaliphatic radical, which optionally contains one or more heteroatoms selected from N, O and S and is optionally mono- or polysubstituted by L,

[0177] L is P-Sp-, F, Cl, Br, I, -CN, -NO 2 , -NCO, -NCS, -OCN, -SCN, -C(=O)NR x R y 、-C(=O)OR x 、-C(=O)R x 、-NR x R y , -OH, -SF 5, optionally substituted silyl, aryl or heteroaryl (having 1 to 12, preferably 1 to 6 C atoms), and straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12, preferably 1 to 6 C atoms, wherein one or more H atoms are optionally replaced by F or Cl,

[0178] R x and R y independently of one another represent H or an alkyl radical having 1 to 12 C atoms,

[0179] Z 1 In the case of multiple occurrences, it represents independently of one another -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O-COO-, -CO-NR x -、-NR x -CO-、-NR x -CO-NR y 、-NR x -CO-O-, -O-CO-NR x -、-OCH 2 -、-CH 2 O-、-SCH 2 -、-CH 2 S-、-CF 2 O-、-OCF 2 -、-CF 2 S-, -SCF 2 -、-CH 2 CH 2 -、-(CH 2 ) n1 , -CF 2 CH 2 -、-CH 2 CF 2 -、-CF 2 CF 2 -, -CH=N-, -N=CH-, -N=N-, -CH=CR x -、-CY 1 =CY 2 -, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond, preferably -COO-, -OCO- or a single bond,

[0180] Y 1 and Y 2 independently of each other represents H, F, Cl or CN,

[0181] n is 1, 2, 3 or 4, preferably 1 or 2, most preferably 2,

[0182] n1 is an integer of 1 to 10, preferably 1, 2, 3 or 4.

[0183] Preferred group A 1 and A 2 Including, but not limited to, furan, pyrrole, thiophene, oxazole, thiazole, thiadiazole, imidazole, phenylene, cyclohexylene, bicyclooctylene, cyclohexenylene, pyridine, pyrimidine, pyrazine, azulene, indane, fluorene, naphthalene, tetralin, anthracene, phenanthrene and dithienothiophene, all of which are unsubstituted or substituted with 1, 2, 3 or 4 groups L as described above.

[0184] Particularly preferred groups A 1 and A 2 is selected from 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, thiophene-2,5-diyl, naphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indan-2,5-diyl, bicyclooctylene or 1,4-cyclohexylene, wherein one or two non-adjacent CH 2 The radicals are optionally substituted by O and / or S, where these radicals are unsubstituted or substituted by 1, 2, 3 or 4 radicals L as described above.

[0185] Preferred RMs of formula DRM are selected from the group consisting of

[0186] DRMa

[0187] in

[0188] P 0 is, in the case of multiple occurrences, independently of one another, a polymerizable group, preferably an acryloyl, methacryloyl, oxetanyl, epoxide, vinyl, heptadiene, vinyloxy, propenyl ether or styryl group,

[0189] Z 0 It is -COO-, -OCO-, -CH 2 CH 2 -、-CF 2 O-、-OCF 2 -, -C≡C-, -CH=CH-, -OCO-CH=CH-, -CH=CH-COO- or a single bond,

[0190] L, at each occurrence, may be identical or different and may have the same or different 1 one of the meanings given and preferably in case of multiple occurrences independently of one another is selected from F, Cl, CN or optionally halogenated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 5 C atoms,

[0191] r is 0, 1, 2, 3, or 4,

[0192] x and y are independently 0 or the same or different integers from 1 to 12, z is 0 or 1, and if the adjacent x or y is 0, then z is 0.

[0193] Very preferred RMs of formula DRM are selected from the following formulae:

[0194]

[0195]

[0196] Where P 0 , L, r, x, y and z are as defined in formula DRMa.

[0197] Particularly preferred are compounds of the formulae DRMa1, DRMa2 and DRMa3, in particular the compound of the formula DRMa1.

[0198] The concentration of di- or polyreactive RMs, preferably RMs of the formula DRM and subformulae thereof, in the RM mixture is preferably from 1% to 60%, very preferably from 10% to 60%, more preferably from 20% to 55%.

[0199] In a preferred embodiment, the polymerisable LC medium comprises, in addition to a di- or poly-reactive RM, preferably selected from the group consisting of a DRM of the formula

[0200] These additional monoreactive RMs are preferably selected from compounds of the formula MRM:

[0201] P 1 -Sp 1 -MG-R MRM

[0202] Where P 1 、Sp 1 and MG has the meaning given to it in Formula DRM,

[0203] R represents P-Sp-, F, Cl, Br, I, -CN, -NO 2 , -NCO, -NCS, -OCN, -SCN, -C(=O)NR x R y , -C(=O)X, -C(=O)OR x 、-C(=O)R y 、-NR x R y , -OH, -SF 5, optionally substituted silyl, straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12, preferably 1 to 6 C atoms, wherein one or more H atoms are optionally replaced by F or Cl,

[0204] X is halogen, preferably F or Cl, and

[0205] R x and R y are independently H or alkyl having 1 to 12 C atoms.

[0206] Preferably, the RM of formula MRM is selected from the following formula.

[0207]

[0208]

[0209]

[0210] Where P 0 , L, r, x, y and z are as defined in formula DRMa,

[0211] R 0 is alkyl, alkoxy, thioalkyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 or more, preferably 1 to 15, C atoms or represents Y 0 or P-(CH 2 ) y -(O) z -

[0212] X 0 Is -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 01 -、-NR 01 -CO-、-NR 01 -CO-NR 01 -、-OCH 2 -、-CH 2 O-、-SCH 2 -、-CH 2 S-、-CF 2 O-、-OCF 2 -、-CF 2 S-, -SCF 2 -、-CF 2 CH 2 -、-CH 2 CF 2 -、-CF 2 CF 2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 01 -, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond,

[0213] Y 0 It is F, Cl, CN, NO 2 、OCH 3 、OCN、SCN、SF 5 or mono-, oligo- or poly-fluorinated alkyl or alkoxy radicals having 1 to 4 C atoms,

[0214] Z 0 It is -COO-, -OCO-, -CH 2 CH 2 -、-CF 2 O-、-OCF 2 -, -CH=CH-, -OCO-CH=CH-, -CH=CH-COO- or a single bond,

[0215] A 0 is, in the case of multiple occurrences, independently of one another, 1,4-phenylene which is unsubstituted or substituted by 1, 2, 3 or 4 radicals L, or trans-1,4-cyclohexylene,

[0216] R 01,02 Independently of each other, H and R 0 or Y 0 ,

[0217] u and v are independently 0, 1 or 2,

[0218] w is 0 or 1,

[0219] The benzene ring and the naphthalene ring may be substituted by one or more identical or different groups L.

[0220] Particularly preferred are compounds of formula MRM1, MRM2, MRM3, MRM4, MRM5, MRM6, MRM7, in particular compounds of formula MRM1, MRM4, MRM6 and MRM7.

[0221] The concentration of all monoreactive RMs in the polymerisable LC medium is preferably from 1 to 80%, very preferably from 5 to 70%, more preferably from 10 to 60%.

[0222] Compounds of the formula DRM, MRM and subformulae thereof can be prepared in analogy to methods known to the person skilled in the art and described in standard works of organic chemistry, for example Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart.

[0223] In a preferred embodiment, the proportion of polymerizable mesogenic compounds in the total polymerizable liquid-crystalline medium according to the invention is in the range from 30 to 99% by weight, more preferably in the range from 40 to 97% by weight, even more preferably in the range from 50 to 95% by weight.

[0224] Preferably, the proportion of the monoreactive liquid crystal compound, direactive liquid crystal compound or polyreactive liquid crystal compound (preferably selected from the compounds of the formula DRM, MRM as given above and below) in the entire polymerizable liquid crystal medium according to the invention is preferably in the range of 30 to 99.9% by weight, more preferably in the range of 40 to 99.9% by weight, even more preferably in the range of 50 to 99.9% by weight.

[0225] In a preferred embodiment, the proportion of di- or polyreactive polymerizable mesogenic compounds in the entire polymerizable liquid-crystalline medium according to the invention is preferably in the range from 5 to 99% by weight, more preferably in the range from 10 to 97% by weight, even more preferably in the range from 15 to 95% by weight.

[0226] In another preferred embodiment, the proportion of the monoreactive polymerizable mesogenic compound, if present, in the entire polymerizable liquid crystal according to the present invention is preferably in the range of 5 to 80 wt.-%, more preferably in the range of 10 to 75 wt.-%, even more preferably in the range of 15 to 70 wt.-%.

[0227] In another preferred embodiment, the proportion of polyreactive polymerizable mesogenic compounds, if present, in the overall polymerizable liquid-crystalline medium according to the invention is preferably in the range from 1 to 30% by weight, more preferably in the range from 2 to 20% by weight, even more preferably in the range from 3 to 10% by weight.

[0228] In another preferred embodiment, the proportion of di- or polyreactive polymerizable mesogenic compounds in the entire polymerizable liquid-crystalline medium according to the invention is in the range from 20 to 70% by weight, more preferably in the range from 30 to 60% by weight, and the proportion of monoreactive polymerizable mesogenic compounds in the entire polymerizable liquid-crystalline medium according to the invention is in the range from 10 to 60% by weight, more preferably in the range from 20 to 50% by weight.

[0229] In another preferred embodiment, the polymerisable LC medium does not comprise polymerisable mesogenic compounds having more than two polymerisable groups.

[0230] In another preferred embodiment, the polymerisable LC medium does not comprise polymerisable mesogenic compounds having less than two polymerisable groups.

[0231] In a further preferred embodiment, the polymerisable LC material comprises one or more monoreactive mesogenic compounds, preferably selected from formulae MRM1, MRM7, MRM9 and MRM10, and one or more direactive mesogenic compounds, preferably selected from formula DRMa1.

[0232] In a further preferred embodiment, the polymerisable LC medium comprises at least two monoreactive mesogenic compounds, preferably selected from compounds of formulae MRM1, MRM7, MRM9 and MRM10, and one or more direactive mesogenic compounds, preferably selected from formula DRMa1.

[0233] In a further preferred embodiment, the polymerisable LC medium comprises at least two monoreactive mesogenic compounds, preferably selected from compounds of formula MRM1, MRM7, MRM9 and MRM10, and at least two direactive mesogenic compounds, preferably selected from compounds of formula DRMa1.

[0234] In a further preferred embodiment, the polymerisable LC medium comprises at least two direactive mesogenic compounds, preferably selected from compounds of formula DRMa1.

[0235] The polymerisable LC medium preferably exhibits a nematic LC phase, or a smectic LC phase and a nematic LC phase, very preferably exhibits a nematic LC phase at room temperature.

[0236] Preferably, the chiral compounds used in the polymerizable LC medium each have a carbonyl group of 20 μm -1 or larger, preferably 40 μm -1 or larger, more preferably 60 μm -1 or larger, most preferably within 80 μm -1 or larger up to 260μm -1 Absolute value of helical twisting force (HTP) within the range of .

[0237] The chiral compound preferably comprises a binaphthyl, isosorbide or isomannide group. The photoreactive chiral compound preferably additionally comprises a cinnamate group, a stilbene group, an azo group or a Schiff base (—CH═N—) group, preferably a cinnamate group.

[0238] The chiral compound may be polymerizable or non-polymerizable. The polymerizable chiral compound preferably comprises one or more, preferably two, polymerizable groups P as described above and below, preferably selected from acrylate groups and methacrylate groups, very preferably from acrylate groups.

[0239] Preferably, the non-polymerizable chiral compound is selected from compounds of formulae CI to C-III,

[0240]

[0241]

[0242] The latter include the corresponding (S,S) enantiomers,

[0243] wherein E and F are each independently 1,4-phenylene or trans-1,4-cyclohexylene, v is 0 or 1, Z 0 -COO-, -OCO-, -CH 2 CH 2 - or a single bond, and R is an alkyl, alkoxy or alkanoyl group having 1 to 12 C atoms.

[0244] Particular preference is given to polymerisable LC media which comprise one or more chiral compounds which do not necessarily exhibit a liquid-crystalline phase.

[0245] Compounds of formula C-II and their synthesis are described in WO 98 / 00428. Compounds of formula C-III and their synthesis are described in GB 2 328 207.

[0246] Furthermore, commonly used chiral compounds are, for example, the commercially available R / S-5011, R / S-811 and CB-15 (from Merck KGaA, Darmstadt, Germany).

[0247] The above-mentioned chiral compound R / S-5011 and the (further) compounds of the formulae CI, C-II and C-III exhibit very high helical twisting powers (HTP) and are therefore particularly suitable for the purposes of the present invention.

[0248] The polymerizable LC medium preferably comprises 1 to 5, in particular 1 to 3, very preferably 1 or 2 chiral compounds, preferably selected from the above formula C-II and / or formula C-III and / or R-5011 or S-5011, and very preferably the chiral compound is R-5011, S-5011.

[0249] Preferably, the polymerisable LC medium comprises one or more non-reactive chiral compounds and / or one or more mono-reactive, di-reactive and / or poly-reactive chiral compounds.

[0250] It is further preferred that the polymerisable LC medium comprises only polymerisable chiral compounds, preferably selected from direactive compounds.

[0251] Suitable mesogenically reactive chiral compounds preferably comprise one or more ring elements linked together by direct bonds or by linking groups, wherein two of these ring elements optionally can be linked to each other directly or via linking groups that are identical or different to the linking groups. The ring elements are preferably selected from four-membered, five-membered, six-membered or seven-membered rings, preferably five-membered or six-membered rings.

[0252] Preferred monoreactive or direactive chiral compounds are selected from the compounds of formula CRMa, CRMb and CRMc:

[0253]

[0254] in

[0255] P 0* represents a polymerizable group P,

[0256] Sp * represents the spacer group Sp,

[0257] R stands for P 0 - or P 0 -Sp * -,

[0258] A 0 and B 0 is, in the case of multiple occurrences, independently of one another, 1,4-phenylene which is unsubstituted or substituted by 1, 2, 3 or 4 radicals L as defined above, or trans-1,4-cyclohexylene,

[0259] X 1 and X 2 are independently -O-, -COO-, -OCO-, -O-CO-O- or a single bond,

[0260] Z 0* In the case of multiple occurrences, independently of one another, are -COO-, -OCO-, -O-CO-O-, -OCH 2 -、-CH 2 O-、-CF 2 O-、-OCF 2 -、-CH 2 CH 2 -、-(CH 2 ) 4 -、-CF 2 CH 2 -、-CH 2 CF 2 -、-CF 2 CF2 -, -C≡C-, -CH=CH-, -CH=CH-COO-, -OCO-CH=CH- or a single bond,

[0261] t is independently 0, 1, 2 or 3,

[0262] a is 0, 1, or 2,

[0263] b is 0 or an integer from 1 to 12,

[0264] z is 0 or 1,

[0265] and wherein the naphthalene ring may additionally be substituted by one or more identical or different groups L wherein,

[0266] L is independently of one another F, Cl, CN, halogenated alkyl having 1 to 5 C atoms, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy.

[0267] The compound of formula CRM is preferably selected from the compounds of formula

[0268]

[0269] Among them A 0 , B 0 , Z 0* , P 0* , a and b have the meanings given in the formula CRM or one of the preferred meanings given above and below, and (OCO) represents -O-CO- or a single bond.

[0270] Particularly preferred compounds of formula CRM are selected from the following sub-formulae:

[0271]

[0272]

[0273]

[0274] wherein R is -X as defined in formula CRMaa 2 -(CH 2 ) x -P 0* , and the benzene ring and the naphthalene ring are unsubstituted or substituted by 1, 2, 3 or 4 groups L as defined above and below.

[0275] In a preferred embodiment, the polymerisable LC medium comprises at least one photoreactive chiral compound in R configuration and at least one chiral compound in S configuration, preferably selected from the group consisting of formulae CRMa to CRMc.

[0276] In a preferred embodiment, the polymerisable LC medium comprises at least one photoreactive chiral compound in S configuration, and at least one chiral compound in R configuration, preferably selected from the group consisting of formulae CRMa to CRMc.

[0277] In a preferred embodiment, the polymerisable LC medium comprises at least one photoreactive chiral compound in the R or S configuration.

[0278] In a preferred embodiment, the configuration of the photoreactive chiral compound is selected to be different from the configuration of the chiral compound not comprising a photoreactive group. For example, if a chiral compound having an R configuration is selected, a photoreactive chiral compound having an S configuration is preferred, and vice versa. Therefore, the individual values ​​of HTP of the individual chiral compounds having different configurations can compensate each other according to their respective helical twisting forces, thereby obtaining the final absolute value of HTP, hereinafter also referred to as |HTP Δ |.

[0279] In a preferred embodiment, the polymerizable LC medium comprises one or more chiral compounds having (S) configuration, and further one or more chiral compounds having (R) configuration, wherein at least one of the chiral compounds having (S) configuration or the chiral compounds having (R) configuration is selected from photoreactive chiral compounds, and the resulting |HTP Δ | at 0.1 μm -1 Up to 100 μm -1 More preferably, it is within the range of 0.5 μm. -1 Up to 50μm -1 The range is preferably 1 μm. -1 Up to 25 μm -1 within the range.

[0280] The photoreactive chiral compound is preferably selected from polymerizable photoreactive chiral compounds, preferably a compound of formula I:

[0281] P-(Sp-X) n -(A 1 -Z 1 ) m -G-(-Z 2 -A 2 -) l -RI

[0282] in,

[0283] P is CH 2 =CW-COO-, WCH=CH-O- or CH 2 =CH-phenyl-(O) k -, where W is H, CH 3 or F, Cl and k are 0 or 1,

[0284] Sp is a spacer group having 1 to 20 C atoms,

[0285] X is a group selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, or a single bond,

[0286] n is 0 or 1,

[0287] Z 1 and Z 2 are independently -COO-, -OCO-, -CH 2 CH 2 -、-OCH 2 -、-CH 2 O-, -CH=CH-, -CH=CH-COO-, -OCO-CH=CH-, -C≡C- or a single bond,

[0288] A 1 and A 2 are each independently 1,4-phenylene, wherein additionally one or more CH groups may be replaced by N, 1,4-cyclohexylene, wherein additionally one or two non-adjacent CH 2 radicals which may be replaced by O and / or S, 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, all of which may be unsubstituted or mono- or polysubstituted by halogen, cyano or nitro or by alkyl, alkoxy or acyl radicals having 1 to 7 C atoms, in which one or more H atoms may be replaced by F or Cl,

[0289] m and l are each independently 0, 1 or 2,

[0290] G is the following structural element

[0291]

[0292] wherein q is 0, 1, 2, 3 or 4, and L is in each case independently halogen, cyano or nitro, or an alkyl, alkoxy or acyl group having 1 to 7 C atoms, wherein one or more H atoms may be substituted by F or Cl, and X is a photoreactive group, preferably a cinnamate group or an azo group, and

[0293] R is an alkyl radical having up to 25 C atoms, which may be unsubstituted, monosubstituted or polysubstituted by halogen or CN, and may also have one or more non-adjacent CH 2 The radicals are each independently of one another -O-, -S-, -NH-, -N(CH 3)-, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S- or -C≡C- is replaced in such a way that the oxygen atoms are not directly connected to each other, or alternatively, R is halogen, cyano or independently has a P-(Sp-X) n - one of the meanings given.

[0294] In a preferred embodiment of the present invention, the photoreactive chiral compound according to formula I is a compound of formula Ia

[0295]

[0296] wherein P, Sp, X, n, L, q and R have the meanings given in formula I.

[0297] In the compounds of formula Ia, P is preferably an acrylate or methacrylate group, particularly preferably an acrylate group, (Sp-X) n Preferably -O-(CH 2 ) p1 -、-OCO-(CH 2 ) p1 -, most preferably -O-(CH 2 ) p1 -, wherein p1 is an integer from 1 to 6, and R is preferably P-(Sp-X) n -, n is preferably 1 and q is preferably 0.

[0298] In another preferred embodiment of the present invention, the photoreactive chiral compound is selected according to formula I or Ia, wherein R has the P-(Sp-X) given above n -One of the meanings.

[0299] In another preferred embodiment of the invention, the photoreactive chiral compound is a compound of the formula I or Ia, wherein R is halogen, cyano or an optionally fluorinated achiral or chiral alkyl or alkoxy group having 1 to 15 C atoms.

[0300] In another preferred embodiment of the present invention, the photoreactive chiral compound is a compound of formula I or Ia, wherein n is 1 and Sp is an alkylene group having 1 to 15 C atoms, and X is -O-, -O-CO-, -CO-O- or a single bond.

[0301] Halogen is preferably F, Cl or Br, particularly preferably F.

[0302] Among the photoreactive chiral compounds of formula I, the following compounds are preferred:

[0303] P-Sp-XGR I1

[0304] P-Sp-XA1 -Z 1 -GZ 2 -A 2 -R I2

[0305] P-Sp-XA 1 -Z 1 -GR I3

[0306] P-Sp-XGZ 2 -A 2 -R I4

[0307] P-Sp-XA 1 -Z 1 -A 1 -Z 1 -GR I5

[0308] P-Sp-XGZ 2 -A 2 -Z 2 -A 2 -R I6

[0309] P-Sp-XA 1 -Z 1 -A 1 -Z 1 -GZ 2 -A 2 -R I7

[0310] P-Sp-XA 1 -Z 1 -GZ 2 -A 2 -Z 2 -A 2 -R I8

[0311] P-Sp-XA 1 -Z 1 -A 1 -Z 1 -GZ 2 -A 2 -Z 2 -A 2 -R I9

[0312] Among them, P, Sp, X, A 1 , A 2 , Z 1 , Z 2 , G and R have the meanings as given above for formula I as described above.

[0313] Among these photoreactive chiral compounds, particular preference is given to compounds of the formulae I1 to I4, very particular preference to compounds of the formulae I1 and I2.

[0314] Particularly preferred photoreactive chiral compounds of the formula I1 are compounds in which n is 1 and R is an alkyl or alkoxy group having 1 to 15 C atoms or has the meaning P-Sp-X-. In addition, -Sp-X- in the compounds of the formula I1 is preferably an alkylene or alkyleneoxy group having 1 to 12 C atoms.

[0315] Among the photoreactive chiral compounds of the formulae I2 to I9, those in which R is alkyl or alkoxy or has the meaning given for P-Sp-X- and Z 1 and Z 2 are independently -COO-, -OCO-, -CH 2 -CH 2 - or single bond compounds.

[0316] In A 1 and A 2 Among the photoreactive chiral compounds representing a heterocyclic group, compounds containing a pyridine-2,5-diyl group, a pyrimidine-2,5-diyl group, or a 1,3-dioxane-2,5-diyl group are particularly preferred.

[0317] A small selection of particularly preferred photoreactive chiral compounds of the formulae I2, I3 and I4 is listed below. For simplicity, PheS is 1,4-phenylene which is substituted in the 2 and / or 3 position by S, where S has one of the meanings given for L in formula I as described above. Furthermore, Pyd is pyridine-2,5-diyl, Pyr is pyrimidine-2,5-diyl, Cyc is 1,4-cyclohexylene, Dio is trans-1,3-dioxane-2,5-diyl, Dit is trans-1,3-dithiane-2,5-diyl, and Nap is tetrahydronaphthalene-2,6-diyl or decahydronaphthalene-2,6-diyl or naphthalene-2,6-diyl. The notations Pyd, Pyr, Dio and Dit include in each case two possible positional isomers.

[0318] Particularly preferred photoreactive chiral compounds of formula I2 are compounds of the following formula:

[0319] P-Sp-X-Phe-Z 1 -GZ 2 -Phe-R I2-1

[0320] P-Sp-X-Phe-Z 1 -GZ 2 -PheS-R I2-2

[0321] P-Sp-X-PheS-Z 1-GZ 2 -Phe-R I2-3

[0322] P-Sp-X-PheS-Z 1 -GZ 2 -PheS-R I2-4

[0323] P-Sp-X-Cyc-Z 1 -GZ 2 -Cyc-R I2-5

[0324] P-Sp-X-Phe-Z 1 -GZ 2 -Cyc-R I2-6

[0325] P-Sp-X-Cyc-Z 1 -GZ 2 -Phe-R I2-7

[0326] P-Sp-X-PheS-Z 1 -GZ 2 -Cyc-R I2-8

[0327] P-Sp-X-Cyc-Z 1 -GZ 2 -PheS-R I2-9

[0328] P-Sp-X-Phe-Z 1 -GZ 2 -Pyr-R I2-10

[0329] P-Sp-X-Phe-Z 1 -GZ 2 -Pyd-R I2-11

[0330] P-Sp-X-Pyd-Z 1 -GZ 2 -Pyd-R I2-12

[0331] P-Sp-X-Pyd-Z 1 -GZ 2 -PheS-R I2-13

[0332] P-Sp-X-Pyr-Z 1 -GZ 2 -PheS-R I2-14

[0333] P-Sp-X-Phe-Z 1 -GZ 2 -Dio-R I2-15

[0334] P-Sp-X-Phe-Z 1 -GZ 2 -Dit-R I2-16

[0335] P-Sp-X-Dio-Z 1 -GZ 2 -Dio-R I2-17

[0336] P-Sp-X-Dit-Z 1 -GZ 2 -Dit-R I2-18

[0337] P-Sp-X-Phe-Z 1 -GZ 2 -Nap-R I2-19

[0338] P-Sp-X-Nap-Z 1 -GZ 2 -Cyc-R I2-20

[0339] In the compounds of formulae I2-1 to I2-20, unless otherwise indicated, P, Sp, X, G, Z 1 , Z 2 and R have the meanings given for formula I described above.

[0340] In the compounds of the formulae I2-1 to I2-20, R is very particularly preferably P-Sp-X- or an alkyl or alkoxy radical having 1 to 15 C atoms. In addition, Z in these compounds 1 Very particular preference is given to ester groups (—CO—O— or —O—CO—), —CH 2 CH 2 - or single key.

[0341] Among the compounds of formulae I2-1 to I2-20, preferred are compounds of formulae I2-1 to I2-9. Particularly preferred are compounds of formulae I2-1 to I2-4.

[0342] Particularly preferred photoreactive chiral compounds of formula I3 are compounds of the formula:

[0343] P-Sp-X-Phe-Z 1 -GR I3-1

[0344] P-Sp-X-PheS-Z 1 -GR I3-2

[0345] P-Sp-X-Cyc-Z 1 -GR I3-3

[0346] P-Sp-X-Dio-Z 1 -GR I3-4

[0347] P-Sp-X-Dit-Z 1 -GR I3-5

[0348] P-Sp-X-Pyr-Z 1 -GR I3-6

[0349] P-Sp-X-Pyd-Z 1 -GR I3-7

[0350] P-Sp-X-Nap-Z 1 -GR I3-8

[0351] Particularly preferred photoreactive chiral compounds of formula I4 are compounds of the formula:

[0352] P-Sp-XGZ 2 -Phe-R I4-1

[0353] P-Sp-XGZ 2 -PheS-R I4-2

[0354] P-Sp-XGZ 2 -Cyc-R I4-3

[0355] P-Sp-XGZ 2 -Dio-R I4-4

[0356] P-Sp-XGZ 2 -Dit-R I4-5

[0357] P-Sp-XGZ 2 -Pyr-R I4-6

[0358] P-Sp-XGZ 2 -Pyd-R I4-7

[0359] P-Sp-XGZ 2 -Nap-R I4-8

[0360] In the compounds of formulae I3-1 to I3-8 and I4-1 to I4-8, unless otherwise indicated, P.Sp, X, G, Z 1 , Z 2 and R have the meanings given above for formula I.

[0361] Among the preferred compounds of the formulae I3-1 to I3-8 and I4-1 to I4-8, those in which R is P-Sp-X- or an alkyl or alkoxy radical having 1 to 15 C atoms and Z 1 -COO-, -OCO-, -CH 2 CH 2 - or those with single bonds.

[0362] If R is an alkyl or alkoxy group, i.e., one in which the terminal CH 2 If the radical is replaced by -O-, it may be straight-chain or branched. It is preferably straight-chain and has 2, 3, 4, 5, 6, 7 or 8 carbon atoms, and is therefore preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy or octyloxy, and furthermore methyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, nonyloxy, decyloxy, undecyl, dodecyl, tridecyl or tetradecyl.

[0363] Oxaalkyl, i.e. one of the CH 2 The radical is replaced by -O-, preferably by, for example, a straight-chain 2-oxapropyl (=methoxymethyl), 2-(=ethoxymethyl), 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-oxanononyl or 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.

[0364] L and S are preferably F, Cl, CN, NO 2 , CH 3 , C 2 H 5 、OCH 3 , OC 2 H 5 、COCH 3 、COC 2 H 5 CF 3 、OCF 3 , especially F, Cl, CN, CH 3 , C 2 H 5 、OCH 3 、COCH 3 and OCF 3 , most preferably F, CH 3 、OCH 3 and COCH 3 .

[0365] In the compounds of formula I, P is CH 2 =CW-COO-, WCH=CH-O- or CH 2 =CH-Phenyl-(O) k -, where W is H, CH 3 Or Cl, and k is 0 or 1.

[0366] P is preferably a vinyl group, an acrylate group, a methacrylate group, an acryl ether group or an epoxy group, and is particularly preferably an acrylate group or a methacrylate group.

[0367] As for the spacer group Sp, all groups known to the person skilled in the art for this purpose can be used. The spacer group Sp is preferably connected to the polymerizable group P via an ester group or an ether group or a single bond. The spacer group Sp is preferably a straight-chain or branched alkylene group having 1 to 20 C atoms, in particular 1 to 12 C atoms, wherein, in addition, one or more non-adjacent CH 2 The group can be -O-, -S-, -NH-, -N(CH 3 )-, -CO-, -O-CO-, -S-CO-, -O-COO-, -CO-S-, -CO-O-, -CH(halogen)-, -CH(CN)-, -CH=CH- or -C≡C-.

[0368] Typical spacer groups are, for example, -(CH 2 ) o -、-(CH 2 CH 2 O) r -、-CH 2 CH 2 -、-CH 2 CH 2 -S-CH 2 CH 2 -or-CH 2 CH 2 -NH-CH 2 CH 2 -, wherein o is an integer from 2 to 12, and r is an integer from 1 to 3.

[0369] Preferred spacer groups are, for example, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene and 1-methylalkylene.

[0370] Particularly preferred are compounds of the formula I wherein n is 1.

[0371] In a preferred embodiment, the polymer is a copolymer obtained by copolymerizing a mixture comprising a compound of the formula I wherein n is 0 and a compound of the formula I wherein n is 1.

[0372] When R or Q 2 When the groups are of the formula P-Sp-X- or P-Sp-, respectively, the spacer groups on both sides of the mesogenic core may be the same or different.

[0373] Chiral photoreactive compounds of the formula I can be prepared, for example, according to or analogously to the methods described in GB 2 314 839B.

[0374] Preferably, the proportion of chiral compounds without photoreactive groups, in particular those selected from the compounds of the formulae CI, C-II, C-III, CRMa, CRMb and CRMc or their subformulae and R / S-5011 in the overall polymerizable liquid-crystalline medium according to the invention is in the range from 0.05 to 2% by weight, very preferably in the range from 0.1 to 1% by weight and most preferably in the range from 0.1 to 0.5% by weight.

[0375] Preferably, the proportion of chiral compounds having photoreactive groups, in particular those selected from the compounds of formula I or its subformulae, in the polymerizable liquid-crystalline medium according to the invention as a whole is in the range from 0.05 to 1% by weight, very preferably in the range from 0.1 to 0.8% by weight and most preferably in the range from 0.1 to 0.4% by weight.

[0376] Preferably, the proportion of chiral compounds without photoreactive groups in the entire polymerizable liquid-crystalline medium according to the invention is less than the proportion of chiral compounds with photoreactive groups in the entire polymerizable liquid-crystalline medium according to the invention. Further preferably, the ratio of the weight % of chiral compounds with photoreactive groups to chiral compounds without photoreactive groups in the polymerizable liquid-crystalline medium according to the invention is from 2:1 to 1:1, more preferably from 1.8:1 to 1.4:1, most preferably from 1.7:1 to 1.5:1.

[0377] In a further preferred embodiment, the polymerizable LC medium optionally comprises one or more additives selected from the group consisting of further polymerization initiators, antioxidants, surfactants, stabilizers, catalysts, sensitizers, inhibitors, chain transfer agents, co-reacted monomers, reactive viscosity reducers, surface-active compounds, lubricants, wetting agents, dispersants, hydrophobic agents, binders, flow improvers, degassing agents or defoamers, deaerators, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments and nanoparticles.

[0378] In another preferred embodiment, the polymerisable LC medium optionally comprises one or more additives selected from polymerisable non-mesogenic compounds (reactive viscosity reducers).The amount of these additives in the polymerisable LC medium is preferably from 0 to 30%, very preferably from 0 to 25%.

[0379] The reactive viscosity reducers used are not only substances which are called reactive viscosity reducers in the actual sense, but also auxiliary compounds already mentioned above, which contain one or more additional reactive units or polymerizable groups P, such as hydroxyl groups, thiol groups or amino groups, through which reactions with polymerizable units of liquid crystal compounds can occur.

[0380] Substances that are generally capable of photopolymerization include, for example, mono-, di- or polyfunctional compounds containing at least one olefinic double bond. Examples are vinyl esters of carboxylic acids, such as vinyl esters of lauric acid, myristic acid, palmitic acid and stearic acid, and vinyl esters of dicarboxylic acids, such as vinyl esters of succinic acid, adipic acid, allyl and vinyl ethers of monofunctional alcohols and methacrylic and acrylates, such as allyl and vinyl ethers and methacrylic and acrylates of lauryl alcohol, myristyl alcohol, palmityl alcohol and stearyl alcohol, and diallyl and divinyl ethers of difunctional alcohols, such as diallyl and divinyl ethers of ethylene glycol and 1,4-butanediol.

[0381] Also suitable are, for example, methacrylates and acrylates of polyfunctional alcohols, in particular those which, in addition to hydroxyl groups, contain no further functional groups or at most ether groups. Examples of such alcohols are difunctional alcohols such as ethylene glycol, propylene glycol and their higher condensation representatives, for example diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, etc., butanediol, pentanediol, hexanediol, neopentyl glycol, alkoxylated phenolic compounds such as ethoxylated and propoxylated bisphenols, cyclohexanedimethanol, trifunctional and polyfunctional alcohols such as glycerol, trimethylolpropane, butanetriol, trimethylolethane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, sorbitol, mannitol, and the corresponding alkoxylated, in particular ethoxylated and propoxylated alcohols.

[0382] Further suitable reactive viscosity reducing agents are polyester (meth)acrylates, which are (meth)acrylate esters of polyester polyols.

[0383] Examples of suitable polyester polyols are those which can be prepared by esterifying polycarboxylic acids, preferably dicarboxylic acids, with polyols, preferably diols. The starting materials for such hydroxyl-containing polyesters are known to those skilled in the art. Dicarboxylic acids which can be used are succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid and isomers and hydrogenation products thereof, and esterifiable or ester transferable derivatives of the acids, such as anhydrides and dialkyl esters. Suitable polyols are the alcohols mentioned above, preferably ethylene glycol, 1,2- and 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol and polyglycols of the ethylene glycol and propylene glycol type.

[0384] Furthermore, suitable reactive viscosity reducers are 1,4-divinylbenzene, triallyl cyanurate, the acrylic ester of tricyclodecenyl alcohol, also known as dihydrodicyclopentadienyl acrylate, and the allyl esters of acrylic acid, methacrylic acid and cyanoacrylic acid.

[0385] Among the reactive viscosity reducing agents mentioned by way of example, use is made in particular and in view of the preferred compositions mentioned above, of those comprising photopolymerizable groups.

[0386] This group includes, for example, diols and polyols, such as ethylene glycol, propylene glycol and higher condensed representatives thereof, for example diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol and the like, butanediol, pentanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, glycerol, trimethylolpropane, butanetriol, trimethylolethane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, sorbitol, mannitol and the corresponding alkoxylated, in particular ethoxylated and propoxylated, alcohols.

[0387] Furthermore, the group includes, for example, alkoxylated phenolic compounds, such as ethoxylated and propoxylated bisphenols.

[0388] Furthermore, these reactive viscosity reducing agents may be, for example, epoxy or urethane (meth)acrylates.

[0389] Epoxy (meth)acrylates are, for example, those obtainable by reaction of epoxidized olefins or poly- or diglycidyl ethers, such as bisphenol A diglycidyl ether, with (meth)acrylic acid, as is known to the person skilled in the art.

[0390] Urethane (meth)acrylates are, in particular, the reaction products of hydroxyalkyl (meth)acrylates with poly- or diisocyanates, which are likewise known to the person skilled in the art.

[0391] Such epoxy and urethane (meth)acrylates are included as "mixed forms" in the compounds listed above.

[0392] If reactive viscosity reducing agents are used, their amount and properties must be matched to the respective conditions so that on the one hand a satisfactory desired effect, such as the desired color of the composition according to the invention, is achieved, but on the other hand the phase behavior of the liquid crystal composition is not excessively impaired. For example, low-crosslinked (high-crosslinked) liquid crystal compositions can be prepared using corresponding reactive viscosity reducing agents having a relatively low (high) number of reactive units per molecule.

[0393] For example, the group of diluents includes:

[0394] C1-C4-alcohols, for example methanol, ethanol, n-propanol, isopropanol, butanol, isobutanol, sec-butanol, and in particular C5-C12-alcohols, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol and n-dodecanol and isomers thereof, diols, for example 1,2-ethanediol, 1,2- and 1,3-propylene glycol, 1,2-, 2,3- and 1,4-butanediol, di- and triethylene glycol and di- and tri-propylene glycol, ethers, for example methyl tert-butyl ether, 1,2-ethanediol mono- and di-methyl ether, 1 , 2-ethylene glycol mono- and di-ethyl ether, 3-methoxypropanol, 3-isopropoxypropanol, tetrahydrofuran and dioxane, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), C1-C5-alkyl esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate and amyl acetate, aliphatic and aromatic hydrocarbons such as pentane, hexane, heptane, octane, isooctane, petroleum ether, toluene, xylene, ethylbenzene, tetralin, decalin, dimethylnaphthalene, white solvent naphtha, and Mineral oils, such as gasoline, kerosene, diesel and heating oil, and natural oils, such as olive, soybean, rapeseed, linseed and sunflower oils.

[0395] It is of course also possible to use mixtures of these diluents in the compositions according to the invention.

[0396] These diluents can also be mixed with water as long as there is at least partial miscibility. Examples of suitable diluents here are C1-C4-alcohols, such as methanol, ethanol, n-propanol, isopropanol, butanol, isobutanol and sec-butanol, diols, such as 1,2-ethanediol, 1,2- and 1,3-propylene glycol, 1,2-, 2,3- and 1,4-butanediol, di- and tri-ethylene glycol and di- and tri-propylene glycol, ethers, such as tetrahydrofuran and dioxane, ketones, such as acetone, methyl ethyl ketone and diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), and C1-C4-alkyl esters, such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate.

[0397] Diluents are optionally used in a proportion of about 0 to 10.0 wt. %, preferably about 0 to 5.0 wt. %, based on the total weight of the polymerisable LC medium.

[0398] Defoamers and deaerators (c1)), lubricants and flow aids (c2)), thermal or radiation curing aids (c3)), substrate wetting aids (c4)), wetting and dispersing aids (c5)), hydrophobic agents (c6)), adhesion promoters (c7)) and agents promoting scratch resistance (c8)) cannot be strictly demarcated from one another in terms of their action.

[0399] For example, lubricants and flow aids are often also used as defoamers and / or degassing agents and / or agents that promote scratch resistance. Radiation curing aids can also be used as lubricants and flow aids and / or degassing agents and / or substrate wetting aids. In various cases, some of these aids can also perform the function of adhesion promoters (c8)).

[0400] Corresponding to what has been said above, certain additives can therefore be classified into several groups c1) to c8) described below.

[0401] The defoamers in group c1) include silicon-free and silicon-containing polymers. Silicon-containing polymers are, for example, unmodified or modified polydialkylsiloxanes or branched, comb or block copolymers comprising polydialkylsiloxane and polyether units, the latter being obtainable from ethylene oxide or propylene oxide.

[0402] Degassing agents from group c1) include, for example, organic polymers, such as polyethers and polyacrylates, dialkylpolysiloxanes, in particular dimethylpolysiloxanes, organomodified polysiloxanes, such as arylalkyl-modified polysiloxanes, and fluorosilicones.

[0403] The action of defoamers is essentially based on preventing foam formation or destroying already formed foam. In a medium to be degassed, for example in the composition according to the invention, defoamers essentially act by promoting the merging of subdivided gas or air bubbles to give larger bubbles and thus accelerate the escape of gas (or air). Since defoamers can often also be used as deaerators and vice versa, these additives have been included together in group c1).

[0404] For example, such additives are available from Tego Foamex 800, Foamex 805, Foamex 810, Foamex 815, Foamex825, Foamex 835, Foamex 840, Foamex 842、 Foamex 1435、 Foamex 1488、 Foamex 1495、 Foamex 3062、 Foamex 7447、 Foamex8020、 Foamex N、 Foamex K 3、 Antifoam 2-18、 Antifoam2-18、 Antifoam 2-57、 Antifoam 2-80、 Antifoam 2-82、 Antifoam 2-89、 Antifoam 2-92、 Antifoam 14、 Antifoam 28、 Antifoam 81、 Antifoam D 90、 Antifoam 93、 Antifoam200、 Antifoam 201、 Antifoam 202、 Antifoam 793、 Antifoam 1488、 Antifoam 3062、 5803、 5852、 5863、 7008、 Antifoam1-60、 Antifoam 1-62、 Antifoam 1-85、 Antifoam2-67、 Antifoam WM 20、 Antifoam 50、 Antifoam105、 Antifoam 730、 Antifoam MR 1015、 Antifoam MR 1016, Antifoam 1435, Antifoam N, Antifoam KS 6, Antifoam KS10, Antifoam KS 53, Antifoam KS95, Antifoam KS100, Antifoam KE 600, Antifoam KS 911, Antifoam MR 1000, Antifoam KS1100, Airex 900, Airex 910, Airex 931, Airex 935, Airex 936, Airex960, Airex 970, Airex 980 and Airex 985 are commercially available and from BYK in -011, -019, -020, -021, -022, -023, -024, -025, -027, -031, -032, -033, -034, -035, -036, -037, -045, -051, -052, -053, -055, -057, -065, -066, -070, -080, -088, -141 and -A 530 is commercially available.

[0405] The auxiliaries in group c1) are optionally used in a proportion of about 0 to 3.0% by weight, preferably about 0 to 2.0% by weight, based on the total weight of the polymerisable LC medium.

[0406] In group c2), lubricants and flow aids generally include silicon-free and silicon-containing polymers, such as polyacrylates or modifiers, low molecular weight polydialkylsiloxanes. The modification consists in that some of the alkyl groups have been replaced by a wide variety of organic groups. These organic groups are, for example, polyethers, polyesters or even long-chain (fluoro)alkyl groups, the former being most frequently used.

[0407] The polyether groups in the correspondingly modified polysiloxanes are usually composed of ethylene oxide and / or propylene oxide units. In general, the higher the proportion of these alkylene oxide units in the modified polysiloxanes, the more hydrophilic the resulting product is.

[0408] For example, such additives are available from Tego Glide 100, Glide ZG 400, Glide 406, Glide 410, Glide 411, Glide 415, Glide 420, Glide 435, Glide 440, Glide 450, Glide A 115, Glide B 1484 (can also be used as a defoamer and deaerator), Flow ATF, Flow 300, Flow 460, Flow 425 and Flow ZFS460 is commercially available. A suitable radiation curable lubricant and flow aid, which can also be used to improve scratch resistance, is the product Rad 2100, Rad 2200, Rad 2500, Rad 2600 and Rad 2700, also available from TEGO.

[0409] Such additives are also available from BYK as -300 -306, -307, -310, -320, -333, -341, 354, 361, 361N, 388 obtained.

[0410] Such additives are also available from 3M, for example

[0411] Such adjuvants are also available, for example, from Cytonix, such as 561 or 562.

[0412] Such auxiliaries are also commercially available, for example, from Merck KGaA, such as FL 2300 and FL2500.

[0413] The auxiliaries in group c2) are optionally used in an amount of about 0 to 3.0% by weight, preferably about 0 to 2.0% by weight, based on the total weight of the polymerisable LC medium.

[0414] In group c3), radiation curing auxiliaries include, in particular, polysiloxanes with terminal double bonds, for example, components whose terminal double bonds are acrylate groups. Such auxiliaries can be crosslinked by actinic or, for example, electron radiation. These auxiliaries usually combine several properties together. In the uncrosslinked state, they can be used as defoamers, degassing agents, lubricants and flow aids and / or substrate wetting aids, while in the crosslinked state, they particularly improve the scratch resistance of, for example, coatings or films that can be prepared using the composition according to the invention. Precisely the improvement of the gloss properties of, for example, those coatings or films is essentially considered to be the result of the action of these auxiliaries as defoamers, degassing agents and / or lubricants and flow aids (in the uncrosslinked state).

[0415] Examples of suitable radiation curing aids are the products available from TEGO Rad2100, Rad2200, Rad 2500, Rad 2600 and Rad 2700 and products available from BYK -371.

[0416] The heat-curing auxiliaries in group c3) contain, for example, primary OH groups which are capable of reacting, for example, with isocyanate groups of the adhesive.

[0417] Examples of useful thermal curing aids are the products available from BYK -370, -373 and -375.

[0418] The auxiliaries in group c3) are optionally used in a proportion of about 0 to 5.0% by weight, preferably about 0 to 3.0% by weight, based on the total weight of the polymerisable LC medium.

[0419] The substrate wetting assistants in group c4) are used in particular to improve the wettability of substrates to be printed or coated, for example, with printing inks or coating compositions, for example the compositions according to the invention. The improvement in the lubrication and flow behavior of such printing inks or coating compositions, which is usually accompanied, has an influence on the appearance of the (for example crosslinked) prints or coatings produced.

[0420] A wide variety of such additives are available, for example, from Tego Wet KL 245, We t250, Wet 260 and Wet ZFS 453 and from BYK -306, -307, -310, -333, -344, -345, -346 and -348 is commercially available.

[0421] The auxiliaries in group c4) are optionally used in a proportion of about 0 to 3.0% by weight, preferably about 0 to 1.5% by weight, based on the total weight of the liquid-crystal composition.

[0422] The wetting and dispersing assistants in group c5) serve in particular to prevent flooding and floating and settling of the pigments and are therefore, if necessary, particularly suitable for use in pigmented compositions.

[0423] These additives stabilize the pigment dispersions substantially by electrostatic repulsion and / or steric hindrance of the pigment particles comprising these additives, wherein in the latter case the interaction of the additives with the surrounding medium (eg binder) plays a major role.

[0424] Since the use of such wetting and dispersing assistants is common practice, for example, in the field of printing ink and coating technology, the selection of suitable assistants of this type generally does not present any difficulties to the person skilled in the art if they are used at all.

[0425] Such wetting and dispersing aids are available, for example, from Tego as Dis pers 610, Dispers610S, Dispers 630, Dispers 700, Dispers 705, Dispers 710, Dispers 720W, Dispers 725W, Dispers 730W, Dispers 735W and Dispers 740W and from BYK -107, -108, -110, -111, -115, -130, -160, -161, -162, -163, -164, -165, -166, -167, -170, -174, -180, -181, -182, -183, -184, -185, -190, Anti- -U、Anti- -U 80、Anti- -P、Anti- -203, Anti- -204、Anti- -206, -151, -154, -155, -P 104 S, -P105, -WS and Commercially available.

[0426] The amount of the auxiliaries in group c5) is used based on the average molecular weight of the auxiliaries. A preliminary experiment is therefore advisable in any case, but this can be easily accomplished by a person skilled in the art.

[0427] The hydrophobic agents in group c6) can be used to impart hydrophobic properties to printed products or coatings produced, for example, using the composition according to the invention. This prevents or at least greatly suppresses swelling due to water absorption and thus, for example, changes in the optical properties of such printed products or coatings. In addition, when the composition is used as a printing ink, for example in offset printing, water absorption can thereby be prevented or at least greatly reduced.

[0428] Such hydrophobic agents are available, for example, from Tego Phobe WF, Phobe1000, Phobe 1000S, Phobe 1010, Phobe 1030, Phobe 1010, Phobe 1010, Phobe 1030, Phobe 1040, Phobe 1050, Phobe 1200, Phobe1300, Phobe 1310 and Phobe 1400 is commercially available.

[0429] The auxiliaries in group c6) are optionally used in a proportion of about 0 to 5.0% by weight, preferably about 0 to 3.0% by weight, based on the total weight of the polymerisable LC medium.

[0430] The additional adhesion promoters from group c7) serve to improve the adhesion of the two interfaces in contact. It is immediately apparent from this that substantially the only part of the effective adhesion promoter is that which is located at one or the other interface or at both interfaces. If, for example, it is desired to apply a liquid or pasty printing ink, a coating composition or a paint to a solid substrate, this generally means that the adhesion promoter must be added directly to the latter, or that the substrate must be pretreated with the adhesion promoter (also referred to as priming), i.e., the substrate is given modified chemical and / or physical surface properties.

[0431] If the substrate has been primed with a primer beforehand, this means that the interfaces in contact are those of the primer on the one hand and the printing ink or coating composition or lacquer on the other hand. In this case, not only the adhesion properties between substrate and primer, but also the adhesion properties between substrate and printing ink or coating composition or lacquer play a role in the adhesion of the entire multilayer structure on the substrate.

[0432] Adhesion promoters in a broader sense may also be mentioned as substrate wetting assistants already listed under group c4), but these generally do not have the same adhesion-promoting capabilities.

[0433] The diversity of adhesion promoter systems is not surprising in view of the widely varying physical and chemical properties of substrates and of the printing inks, coating compositions and lacquers intended for, for example, printing or coating thereof.

[0434] Adhesion promoters based on silanes are, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, N-aminoethyl-3-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, N-methyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane and vinyltrimethoxysilane. These and other silanes are available from Hüls, for example under the trade name Commercially available.

[0435] Generally, the corresponding technical information from the manufacturers of such additives should be used or the person skilled in the art can determine this information in a simple manner by corresponding preliminary experiments.

[0436] If, however, these additives are to be added as auxiliaries from group c7) to the polymerizable LC medium according to the invention, their proportion optionally corresponds to about 0 to 5.0% by weight, based on the total weight of the polymerizable LC medium. These concentration data serve only as a guide, since the amount and identity of the additive is determined in each individual case by the properties of the substrate and the printing / coating composition. For this case, the corresponding technical information is generally available from the manufacturers of such additives or can be determined in a simple manner by a person skilled in the art by corresponding preliminary experiments.

[0437] The auxiliaries in group c8) for improving scratch resistance include, for example, the above-mentioned products available from Tego Rad 2100, Rad 2200, Rad 2500, Rad 2600 and Rad 2700.

[0438] The quantitative data given for group c3) also apply to these auxiliaries, ie these additives are optionally used in a proportion of about 0 to 5.0% by weight, preferably about 0 to 3.0% by weight, based on the total weight of the liquid-crystal composition.

[0439] Examples of other light, heat and / or oxidation stabilizers which may be mentioned are the following substances:

[0440] Alkylated monophenols, such as 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethylphenol, 2,6-di(octadecyl)-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenol with linear or branched side chains, such as such as 2,6-dinonyl-4-methylphenol, 2,4-dimethyl-6-(1′-methylundecane-1′-yl)phenol, 2,4-dimethyl-6-(1′-methylheptadecan-1′-yl)phenol, 2,4-dimethyl-6-(1′-methyltridecane-1′-yl)phenol and mixtures of these compounds, alkylthiomethylphenols such as 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol and 2,6-di(dodecyl)thiomethyl-4-nonylphenol,

[0441] Hydroquinones and alkylated hydroquinones, such as 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydrocrainone, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate and bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate,

[0442] Tocopherols, such as alpha-tocopherol, beta-tocopherol, gamma-tocopherol, delta-tocopherol and mixtures of these compounds, and tocopherol derivatives, such as tocopherol acetate, succinate, nicotinate and polyoxyethylene succinate ("tocofersolate"),

[0443] Hydroxylated diphenyl sulfides, such as 2,2′-thiobis(6-tert-butyl-4-methylphenol), 2,2′-thiobis(4-octylphenol), 4,4′-thiobis(6-tert-butyl-3-methylphenol), 4,4′-thiobis(6-tert-butyl-2-methylphenol), 4,4′-thiobis(3,6-di-sec-amylphenol) and 4,4′-bis(2,6-dimethyl-4-hydroxyphenyl) disulfide,

[0444] Alkylenebisphenols, for example 2,2′-methylenebis(6-tert-butyl-4-methylphenol), 2,2′-methylenebis(6-tert-butyl-4-ethylphenol), 2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol], 2,2′-methylenebis(4-methyl-6-cyclohexylphenol), 2,2′-methylenebis(6-nonyl-4-methylphenol), 2,2′-methylenebis(4,6-di-tert-butylphenol), 2,2-ethylenebis( 4,6-di-tert-butylphenol), 2,2′-ethylenebis(6-tert-butyl-4-isobutylphenol), 2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol], 2,2′-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4′-methylenebis(2,6-di-tert-butylphenol), 4,4′-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2- methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tri(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecyl-mercaptobutane, ethylene glycol bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene, bis(3-tert-butyl-4-hydroxy-5-methylphenyl) [2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl] terephthalate, 1,1-bis(3,5-dimethyl-2-hydroxyphenyl)butane, 2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecyl-mercaptobutane and 1,1,5,5-tetrakis(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane,

[0445] O-, N- and S-benzyl compounds, such as 3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether, 4-hydroxy-3,5-dimethylbenzylthioglycolate octadecyl, 4-hydroxy-3,5-di-tert-butylbenzylthioglycolate tridecyl, tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine, bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide and isooctyl-3,5-di-tert-butyl-4-hydroxybenzylthioglycolate,

[0446] Aromatic hydroxybenzyl compounds, such as 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethyl-benzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethyl-benzene and 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol,

[0447] Triazine compounds, such as 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, -tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexahydro-1,3,5-triazine, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl) isocyanurate and 1,3,5-tris(2-hydroxyethyl) isocyanurate,

[0448] Benzylphosphonates, such as dimethyl 2,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and dioctadecyl 5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate,

[0449] Acylaminophenols, such as 4-hydroxylauroylanilide, 4-hydroxystearylanilide and octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate,

[0450] for example propionates and acetates of monohydric or polyhydric alcohols, such as methanol, ethanol, n-octanol, isooctyl alcohol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane and 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]-octane,

[0451] Propionamides based on amine derivatives, such as N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine, N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine and N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine,

[0452] Ascorbic acid (vitamin C) and ascorbic acid derivatives, such as ascorbyl palmitate, ascorbyl laurate and ascorbyl stearate, as well as ascorbyl sulfate and ascorbyl phosphate,

[0453] Antioxidants based on amine compounds, such as N,N′-diisopropyl-p-phenylenediamine, N,N′-di-sec-butyl-p-phenylenediamine, N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N′-bis(1-methylheptyl)-p-phenylenediamine, N,N′-dicyclohexyl-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine, N,N′-bis(2-naphthyl)-p-phenylenediamine, N-isopropyl-N′-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine, N -cyclohexyl-N′-phenyl-p-phenylenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N′-dimethyl-N,N′-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyl diphenylamine, 4-isopropoxy diphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octyl-substituted diphenylamines such as p,p′-di-tert-octyl diphenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol, 4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminophenol methylphenol, 2,4-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, N,N,N′,N′-tetramethyl-4,4′-diaminodiphenylmethane, 1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane, (o-tolyl)biguanide, bis[4-(1′,3′-dimethylbutyl)phenyl]amine, tert-octyl-substituted N-phenyl-1-naphthylamine, mixtures of mono- and di-alkylated tert-butyl / tert-octyl diphenylamines, mixtures of mono- and di-alkylated nonyl diphenylamines, mixtures of mono- and di-alkylated dodecyl diphenylamines, mixtures of mono- and di-alkylated isopropyl / isohexyl diphenylamines mixtures of mono- and di-alkylated tert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, mixtures of mono- and di-alkylated tert-butyl / tert-octyl phenothiazines, mixtures of mono- and di-alkylated tert-octyl phenothiazines, N-allyl phenothiazine, N,N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene, N,N-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine, bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate, 2,2,6,6-tetramethylpiperidin-4-one and 2,2,6,6-tetramethylpiperidin-4-ol,

[0454] Phosphines, phosphites and phosphonites, such as triphenylphosphine, triphenylphosphite, diphenylalkylphosphites, phenyldialkylphosphites, tris(nonylphenyl)phosphite, trilaurylphosphite, trioctadecylphosphite, distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, diisodecylpentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, diisodecylpentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite, bis(2,4,6 -tri(tert-butylphenyl))pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4′-diphenylene diphosphite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocine, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocine, bis(2,4-di-tert-butyl-6-methylphenyl)methylphosphite and bis(2,4-di-tert-butyl-6-methylphenyl)ethylphosphite,

[0455] 2-(2′-hydroxyphenyl)benzotriazole, such as 2-(2′-hydroxy-5′-methylphenyl)benzotriazole, 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5 -chlorobenzotriazole, 2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole, 2-(2′-hydroxy-4′-octyloxyphenyl)benzotriazole, 2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole, 2-(3,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)benzotriazole, a mixture of 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3′-tert-butyl-5′ -[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)-5-chlorobenzotriazole ]-2′-hydroxyphenyl)benzotriazole, 2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole and 2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-ylphenol]; the fully esterified product of 2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazole and polyethylene glycol 300;

[0456] Sulfur-containing peroxide scavengers and sulfur-containing antioxidants, such as esters of 3,3′-thiodipropionic acid, for example the lauryl, stearyl, myristyl and tridecyl esters, mercaptobenzimidazole and the zinc salt of 2-mercaptobenzimidazole, dibutyl zinc dithiocarbamate, dioctadecyl disulfide and pentaerythritol tetrakis(β-dodecylmercapto)propionate,

[0457] 2-Hydroxybenzophenones, such as the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2′,4′-trihydroxy and 2′-hydroxy-4,4′-dimethoxy derivatives,

[0458] Esters of unsubstituted and substituted benzoic acid, such as 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis(4-tert-butylbenzoyl)resorcinol, benzoylresorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl-3,5-di-tert-butyl-4-hydroxybenzoate and 2-methyl-4,6-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate,

[0459] Acrylates, such as ethyl α-cyano-β,β-diphenylacrylate, isooctyl α-cyano-β,β-diphenylacrylate, methyl α-methoxycarbonylcinnamate, methyl α-cyano-β-methyl-p-methoxycinnamate, butyl-α-cyano-β-methyl-p-methoxycinnamate and methyl-α-methoxycarbonyl-p-methoxycinnamate, sterically hindered amines, such as bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate, bis(2,2,6,6-tetramethylpiperidin-4-yl)succinate, bis(1,2,2,6,6-pentamethylpiperidin-4-yl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) Sebacate, bis(1,2,2,6,6-pentamethylpiperidin-4-yl)-n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, condensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, condensation product of N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethylpiperidin-4-yl) nitrilotriacetate, tetrakis(2,2,6,6-tetramethylpiperidin-4-yl)1,2,3,4-butanetetracarboxylate, 1,1′-(1,2-ethyl)-2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine )bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethylpiperidin-4-yl)2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)succinate, N,N′-bis(2 , 2,6,6-tetramethylpiperidin-4-yl) hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, condensation products of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidin-4-yl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane, condensation products of 2-chloro-4,6-bis(4-n-butylamino-1,2,2,6,6-pentamethylpiperidin-4-yl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]-decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethylpiperidin-4-yl)pyrrolidine-2,5-dione, 3-dodecyl-1-(1,2,2,6,6-pentamethylpiperidin-4-yl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidin, a condensation product of N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, a condensation product of 1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine, a condensation product of 4-butylamino-2,2,6,6-tetramethyl piperidine, N-(2,2,6,6-tetramethylpiperidin-4-yl)-n-dodecylsuccinimide, N-(1,2,2,6,6-pentamethylpiperidin-4-yl)-n-dodecylsuccinimide, 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4.5]-decane, condensation products of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro[4.5]decane and epichlorohydrin, condensation products of 4-amino-2,2,6,6-tetramethylpiperidine with tetrakishydroxymethylacetylene diurea and poly(methoxypropyl-3-oxy)-[4(2,2,6,6-tetramethyl)piperidinyl]-siloxane,.

[0460] Oxamides, such as 4,4′-dioctyloxyoxalanilide, 2,2′-diethoxyoxalanilide, 2,2′-dioctyloxy-5,5′-di-tert-butoxanilide, 2,2′-di(dodecyloxy)-5,5′-di-tert-butoxanilide, 2-ethoxy-2′-ethyloxalanilide, N,N′-bis(3-dimethylaminopropyl)oxalamide, 2-ethoxy-5-tert-butyl-2′-ethoxanilide and mixtures thereof with 2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide, and mixtures of o- and p-methoxy-disubstituted oxalanilides and mixtures of o- and p-ethoxy-disubstituted oxalanilides, and

[0461] 2-(2-hydroxyphenyl)-1,3,5-triazine, such as 2,4,6-tris-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propoxyphenyl)-6-(2,4-dimethylphenyl)- 1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-butoxypropoxy)phenyl]-4,6 -bis(2,4-dimethyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy / tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6- Bis-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-hexyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine and 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine.

[0462] In another preferred embodiment, the polymerizable LC medium comprises preferably selected from One or more specific antioxidant additives from the VIZOL series, such as antioxidants available from Ciba, Switzerland. 1076 and 1010.

[0463] In another preferred embodiment, the polymerisable LC medium comprises one or more, more preferably two or more photoinitiators, for example selected from the commercially available or (Ciba AG) series, in particular, Irgacure 127, Irgacure 184, Irgacure 369, Irgacure 651, Irgacure 817, Irgacure 907, Irgacure 1300, Irgacure, Irgacure 2022, Irgacure 2100, Irgacure 2959 or Darcure TPO. In particular, the polymerizable LC medium comprises preferably one or more oxime ester photoinitiators, preferably selected from the commercially available OXE02 (Ciba AG), NCI930, N1919T (Adeka), SPI-03 or SPI-04 (Samyang).

[0464] The concentration of the polymerisation initiator in the total polymerisable LC medium is preferably from 0.5 to 10%, very preferably from 0.8 to 8%, more preferably from 1 to 6%.

[0465] Preferably, the polymerisable LC medium comprises a given ratio between the photoinitiator concentration and the overall concentration of all chiral compounds in the range of 1:1 to 1:5, more preferably in the range of 1:1 to 1:4, even more preferably in the range of 1:1 to 1:3.

[0466] In a preferred embodiment, the polymerisable LC medium is dissolved in a suitable solvent, which is preferably selected from organic solvents.

[0467] The solvent is preferably selected from ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone or cyclohexanone; acetates such as methyl acetate, ethyl acetate or butyl acetate or methyl acetoacetate; alcohols such as methanol, ethanol or isopropanol; aromatic solvents such as toluene or xylene; alicyclic hydrocarbons such as cyclopentane or cyclohexane; halogenated hydrocarbons such as di- or tri-chloromethane; glycols or their esters such as PGMEA (propylene glycol monomethyl ether acetate), γ-butyrolactone. It is also possible to use binary, ternary or higher-order mixtures of the above solvents.

[0468] In case the polymerisable LC medium comprises one or more solvents, the total concentration of all solids (including RMs) in the solvent is preferably from 10% to 60%.

[0469] Preferably, the polymerisable LC medium comprises,

[0470] a) one or more di- or poly-reactive polymerizable mesogenic compounds,

[0471] b) optionally one or more monoreactive polymerizable mesogenic compounds, preferably selected from the compounds of formulae MRM1, MRM7, MRM9 and / or MRM10 and the corresponding subformulae thereof,

[0472] c) one or more chiral mesogenic compounds of (S) configuration, preferably selected from the compounds of formula CRMa, CRMb or CRMc, more preferably formula CRMaa and its subformulae,

[0473] d) one or more photoreactive chiral mesogenic compounds of (R) configuration, preferably selected from the compounds of formula I, very preferably selected from the compounds of formula Ia,

[0474] e) optionally one or more antioxidant additives,

[0475] f) optionally one or more adhesion promoters,

[0476] g) optionally one or more surfactants,

[0477] h) optionally one or more monoreactive, direactive or polyreactive polymerizable non-mesogenic compounds,

[0478] i) optionally one or more dyes showing an absorption maximum at the wavelength used to initiate photopolymerization,

[0479] j) optionally one or more chain transfer agents,

[0480] k) optionally one or more other stabilizers,

[0481] l) optionally one or more lubricants and flow aids, and

[0482] m) optionally one or more diluents,

[0483] n) optionally a non-polymerizable nematic component,

[0484] o) optionally one or more organic solvents.

[0485] Alternatively, the polymerisable LC medium comprises,

[0486] a) one or more di- or poly-reactive polymerizable mesogenic compounds,

[0487] b) optionally one or more monoreactive polymerizable mesogenic compounds, preferably selected from the compounds of formulae MRM1, MRM7, MRM9 and / or MRM10 and the corresponding subformulae thereof,

[0488] c) one or more chiral mesogenic compounds of (R) configuration, preferably selected from the compounds of formula CRMa, CRMb or CRMc, more preferably formula CRMaa and its subformulae,

[0489] d) one or more photoreactive chiral mesogenic compounds of (S) configuration, preferably selected from the compounds of formula I, very preferably selected from the compounds of formula Ia,

[0490] e) optionally one or more antioxidant additives,

[0491] f) optionally one or more adhesion promoters,

[0492] g) optionally one or more surfactants,

[0493] h) optionally one or more monoreactive, direactive or polyreactive polymerizable non-mesogenic compounds,

[0494] i) optionally one or more dyes showing an absorption maximum at the wavelength used to initiate photopolymerization,

[0495] j) optionally one or more chain transfer agents,

[0496] k) optionally one or more other stabilizers,

[0497] l) optionally one or more lubricants and flow aids, and

[0498] m) optionally one or more diluents,

[0499] n) optionally a non-polymerizable nematic component,

[0500] o) optionally one or more organic solvents.

[0501] The polymerisable LC media according to the invention are prepared in a manner conventional per se, for example by mixing one or more of the above-mentioned photoreactive chiral compounds with one or more direactive LC compounds and one or more chiral compounds as defined above, and optionally with further additives.

[0502] The present invention also relates to a method for preparing a polymer film, comprising, preferably consisting of, the following steps:

[0503] - providing a layer of a polymerisable LC medium as described above and below on a substrate, the substrate optionally being provided with an alignment layer capable of inducing a planar alignment relative to an adjacent layer of the polymerisable LC medium,

[0504] - in a first step, irradiating the layer stack in air with actinic radiation, preferably with UV radiation (first UV step), and

[0505] In a second step, in an inert gas atmosphere, the layer stack is irradiated with actinic radiation, preferably with UV radiation (second UV step).

[0506] The invention also relates to a polymer film obtainable by this process.

[0507] More preferably, the method for preparing the polymer according to the present invention comprises the following steps:

[0508] - providing a layer of a polymerisable LC medium as described above and below or a solution thereof onto a substrate, preferably provided with an alignment layer, such as a rubbed polyimide layer or a photoalignment layer, inducing a planar alignment layer, e.g. by spin coating or printing methods, and optionally removing any solvent present,

[0509] - exposing the layer of polymerizable LC medium to UV light, which results in photoisomerization of the chiral compound comprising a photoisomerizable group and provides a chiral structure with an offset helical pitch, preferably to non-polarized UV light, very preferably to non-polarized UVA light, at a dose of, for example, 40 to 500 mJ / cm 2 , preferably in an air environment at ambient temperature ("first UV step"),

[0510] - exposing the layer of polymerisable LC medium to UV light, which results in photopolymerisation of the polymerisable mesogenic compound, preferably to non-polarised UV light, very preferably to non-polarised UVA light, e.g. in a dose of 200 to 2000 mJ / cm 2 , preferably under an inert gas atmosphere, such as nitrogen, and at ambient temperature ("second UV step").

[0511] Preferably, in the method according to the invention all irradiation or UV exposure steps are carried out at room temperature and the layers of the polymerisable LC medium are not subjected to a heat treatment during or between the irradiation or UV exposure steps.

[0512] The first irradiation or first UV step results in photoisomerization of the chiral compound comprising a photoisomerizable group and provides a chiral structure with an offset helical pitch. The second irradiation or second UV step results in photopolymerization of the polymerizable mesogenic compound, thereby fixing the chiral structure.

[0513] The polymerisable LC medium may be coated or printed onto a substrate, for example by spin coating, printing or other known techniques, and the solvent evaporated off prior to polymerisation. In most cases it will be appropriate to heat the mixture to facilitate evaporation of the solvent.

[0514] The polymerisable LC medium can be applied to the substrate by conventional coating techniques such as spin coating, rod coating or doctor blade coating. The polymerisable LC medium can also be applied to the substrate by conventional printing techniques known to the person skilled in the art, such as for example screen printing, offset printing, roll-to-roll printing, letterpress printing, gravure printing, rotogravure printing, flexographic printing, gravure printing, pad printing, heat seal printing, inkjet printing or printing with the aid of a stamps or printing plates.

[0515] Suitable substrate media and substrates are known to the person skilled in the art and are described in the literature, such as conventional substrates used, for example, in the optical film industry, such as glass or plastics. Particularly suitable and preferred substrates for polymerization are polyesters such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyvinyl alcohol (PVA), polycarbonate (PC), triacetyl cellulose (TAC), cycloolefin polymers (COP), or known color filter materials, preferably triacetyl cellulose (TAC), cycloolefin polymers (COP) or known color filter materials.

[0516] The Friedel-Creagh-Kmetz rule compares the RM layers (γ RM ) and substrate (γ s ) can be used to predict whether the mixture will adopt a planar or homeotropic orientation:

[0517] If γ RM >γ s , then the reactive mesogenic compound will show a homeotropic alignment if γ RM <γ s , then the reactive mesogen compound will show plane alignment.

[0518] Without being bound by theory, when the surface energy of the substrate is relatively low, the intermolecular forces between the reactive mesogens are stronger than the forces across the RM-substrate surface, and therefore, the reactive mesogens align perpendicular to the substrate (homeotropic alignment) to maximize the intermolecular forces. Therefore, an additional alignment layer is required that can induce planar alignment with the adjacent polymerizable LC medium.

[0519] When the surface tension of the substrate is greater than the surface tension of the RM, the force across the interface dominates. If the reactive mesogen is aligned parallel to the substrate, so that the major axis of the RM can interact with the substrate, the interface energy is minimized. One method to promote planar alignment can be by coating the substrate with a polyimide layer and then rubbing the alignment layer with a velvet cloth. Other suitable planar alignment layers are known in the art, such as, for example, rubbed polyimide or alignment layers prepared by photoalignment, as described in US 5,602,661, US 5,389,698 or US 6,717,644.

[0520] In general, an overview of alignment techniques is given by I. Sage in "Thermotropic Liquid Crystals", edited by GWGray, John Wiley & Sons, 1987, pp. 75-77; and by T. Uchida and H. Seki in "Liquid Crystals - Applications and Uses Vol. 3", edited by B. Bahadur, World Scientific Publishing, Singapore 1992, pp. 1-63. A further overview of alignment materials and techniques is given by J. Cognard, Mol. Crystal. Liq. Crystal. 78, Supplement 1 (1981), pp. 1-77.

[0521] In a preferred embodiment, the method according to the invention comprises a method step wherein the polymerisable LC medium is allowed to stand for a period of time in order to uniformly redistribute the polymerisable LC medium on the substrate (referred to herein as "annealing").

[0522] In a preferred embodiment, after providing the polymerisable LC medium on the substrate, the layer stack is annealed for a period of 10 seconds to 1 hour, preferably 20 seconds to 10 minutes, most preferably 30 seconds to 2 minutes. Annealing is preferably performed at room temperature.

[0523] The polymerisable LC medium preferably consists of compounds which align spontaneously when deposited as a mixture onto a substrate.Thus, the LC medium is preferably not subjected to a heat treatment prior to UV exposure to align the mesogenic or liquid crystalline compounds.

[0524] If necessary, the layer stack can be cooled to room temperature after the high-temperature annealing. The cooling can be done actively with the aid of a cooling aid or passively by simply letting the layer stack stand for a given time.

[0525] In a preferred embodiment, the polymerisable LC medium is exposed to actinic radiation in a first UV step, for example as described in WO 01 / 20394, GB 2,315,072 or WO 98 / 04651.

[0526] Actinic radiation means irradiation with light, such as UV light, IR light or visible light, irradiation with X-rays or gamma rays, or irradiation with high-energy particles, such as ions or electrons. Preferably, the first UV step is performed by irradiation with light, in particular with UV light, especially with UVA light.

[0527] As a source of actinic radiation, for example, a single UV lamp or a group of UV lamps can be used. When using high lamp powers, the curing time can be shortened. Another possible source of actinic radiation is a laser, such as a UV laser, an IR laser or a visible laser.

[0528] The curing time depends, inter alia, on the reactivity of the photoreactive compound, the thickness of the coating, and the power and selected wavelength of the UV lamp, etc. The curing time is preferably ≤5 minutes, very preferably ≤3 minutes, most preferably ≤1 minute. For large-scale production, a short curing time of ≤30 seconds is preferred.

[0529] The UV radiation power in the first UV step is preferably between 5 and 300 mWcm -2 In the range of 50 to 250 mWcm -2 and most preferably in the range of 100 to 180 mWcm -2 within the range.

[0530] Suitable UV doses are preferably between 20 and 1000 mJcm, depending on the UV radiation applied and as a function of time. -2 In the range of 30 to 800 mJcm -2 In the range of 40 to 500 mJcm -2 The range of 40 to 200 mJcm is most preferred. -2 within the range.

[0531] The first irradiation step or first UV step is preferably carried out in air.

[0532] The first irradiation step or first UV step is preferably performed at room temperature.

[0533] The photopolymerization of the polymerizable LC medium in the second irradiation step is preferably achieved by exposing it to actinic radiation. Actinic radiation refers to irradiation with light, such as UV light, IR light or visible light, irradiation with X-rays or gamma rays, or irradiation with high-energy particles, such as ions or electrons. Preferably, the polymerization is carried out by irradiation, in particular with UV light. As a source for actinic radiation, for example a single UV lamp or a group of UV lamps can be used. When high lamp powers are used, the curing time can be reduced. Another possible source for photoradiation is a laser, such as for example a UV laser, an IR laser or a visible laser.

[0534] The curing time of the photopolymerization depends inter alia on the reactivity of the polymerizable LC medium, the thickness of the coating layer, the type of polymerization initiator and the power of the UV lamp. The curing time is preferably ≤5 minutes, very preferably ≤3 minutes, most preferably ≤1 minute. For mass production, a short curing time of ≤30 seconds is preferred.

[0535] Suitable UV radiation power for photopolymerization is preferably in the range of 100 to 1000 mWcm -2 In the range of 200 to 800 mWcm -2 and most preferably in the range of 300 to 600 mWcm -2 within the range.

[0536] Suitable UV doses are preferably in the range of 25 to 16500 mJcm, depending on the UV radiation applied and as a function of time. -2 In the range of 50 to 7200 mJcm -2 In the range of 100 to 3500 mJcm -2 and most preferably in the range of 200 to 2000 mJcm -2 within the range.

[0537] The photopolymerization (second irradiation step or second UV step) is preferably carried out in an inert gas atmosphere, preferably in a nitrogen atmosphere.

[0538] The photopolymerization (second irradiation step or second UV step) is preferably carried out at room temperature.

[0539] The preferred thickness of the polymerized LC film according to the present invention is determined by the optical properties required for the film or the final product.

[0540] For optical applications of the polymer film, it preferably has a thickness of 0.5 to 10 μm, preferably 0.5 to 5 μm, in particular 0.5 to 3 μm.

[0541] After photopolymerization, the resulting polymer film can be removed from the substrate and combined with other substrates or optical films by lamination processes known to those skilled in the art. Suitable substrates and optical films are given above and include, among others, polarizers, especially linear polarizers.

[0542] Without wishing to be bound by theory, the inventors believe that the presence of oxygen in the air during the first UV step inhibits free radical polymerization. This effect can be exploited to partially polymerize the film with a gradient in the film depth. The top of the film exposed to oxygen has a low polymerization rate. The bottom of the film at the substrate interface is much less inhibited by oxygen, so polymerization occurs more easily.

[0543] Due to the presence of at least one photoreactive chiral compound, photoisomerization occurs during the first UV step, and the helical twisting power (HTP) of the photoreactive chiral compound is reduced when exposed to UV light. In areas where the polymer density is higher, changes in the chiral structure are physically resisted. At the top or surface of the film, the polymer density is low, so the chiral structure can be modified more freely. However, at the bottom of the film adjacent to the substrate, more photopolymerization occurs, the polymer density is higher, and therefore changes in the chiral structure are hindered. This results in a chiral pitch gradient in the film. Therefore, after performing the above method, the polymerized LC medium exhibits accelerated chiral rotation in the main plane of the polymer film or in the thickness direction of the film. Preferably, the polymerized LC medium exhibits an offset pitch so that the chiral rotation angle gradually increases or decreases throughout the thickness of the film.

[0544] In the polymer film according to the present invention, the minimum twist angle is preferably 0°. It is further preferred that the maximum twist angle is in the range of 70 to 150°, very preferably 80 to 120°, most preferably 90 to 110°. Preferably, the twist angle varies in the film thickness direction from 0° to 150°, very preferably from 0° to 120°, most preferably from 0° to 100°. Preferably, the lower twist value is located on the side of the polymer film adjacent to the substrate on which the polymer film is prepared. The average twist angle in the polymer film is preferably in the range of 10 to 40°, very preferably from 15 to 35°, most preferably from 20 to 30°.

[0545] Preferably, the polymer film according to the invention has a negative optical dispersion. Preferably, the polymer film according to the invention has an optical retardation of 110 nm to 170 nm at 550 nm, very preferably 130 nm to 150 nm; and 90 nm to 140 nm at 450 nm, very preferably 110 nm to 120 nm.

[0546] In summary, the polymerized LC films and polymerizable LC media according to the present invention can be used in optical components or elements.

[0547] The polymerized LC films and polymerizable LC media according to the invention can be used in displays of the transmissive or reflective type, in particular they can be used in conventional OLED displays or LCDs, in particular OLED displays.

[0548] The invention has been described in the context of particular reference to preferred embodiments thereof. It should be understood that various changes and modifications can be made therein without departing from the spirit and scope of the invention.

[0549] Many of the compounds or mixtures thereof mentioned above and below are commercially available. All these compounds are known or can be prepared by methods known per se as described in the literature (for example in standard works such as Houben-Weyl, Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart), precisely under reaction conditions known and suitable for the described reactions. Variants known per se and not mentioned here can also be used here.

[0550] It should be understood that the aforementioned embodiments of the present invention may be modified while still falling within the scope of the present invention. Unless otherwise specified, alternative features for the same, equivalent or similar purposes may replace each feature disclosed in this specification. Therefore, unless otherwise specified, each feature disclosed is merely an example of a general concept of an equivalent or similar feature.

[0551] All features disclosed in this specification may be combined in any combination except where at least some of such features and / or steps are mutually exclusive. In particular, preferred features of the present invention are applicable to all aspects of the present invention and may be combined in any combination. Likewise, features described in non-essential combinations may be used separately (not in combination).

[0552] It should be understood that many of the features described above, particularly the features of the preferred embodiments, are inventive in themselves, and not just as part of an embodiment of the present invention. Independent protection for these features may be sought in addition to or in lieu of any invention currently claimed.

[0553] The present invention will now be described in more detail with reference to the following working examples, which are merely illustrative and do not limit the scope of the present invention. DETAILED DESCRIPTION

[0554] Example 1

[0555] Prepare mixture RMM1 according to the following table:

[0556]

[0557] 1076 is a commercially available stabilizer (Ciba AG, Basel, Switzerland). -930 is a commercially available photoinitiator (Adeka Coorporation, Japan). -310 is a commercially available surfactant from BYK (BYK, Germany).

[0558] Polymer film forming process

[0559] The RMM-1 mixture was converted into a formulation by dissolving it in a solvent blend of toluene:cyclohexanone (7:3) at a ratio of 36% solid to 64% solvent by mass. Nissan PAL HSPA-152 was coated on a 60 μm TAC substrate using an MB#3 rod. The substrate was then baked at 110°C for 60 seconds and exposed to polarization using a wire grid polarizer and a high pressure mercury lamp (LH6 fusion) at 67 mW / cm 2 and 12mJ / cm 2 The formulation was coated on an alignment layer obtained from Nissan PAL HSPA-152 using a MB#6 rod, annealed at 60°C for 60 seconds, and then illuminated using a high pressure mercury lamp (LH6 fusion) at 180 mW / cm 2 and 40mJ / cm 2 UVA was used for UV light exposure. After the first UV step, the sample was purged with nitrogen for 60 seconds and finally exposed to light using a high pressure mercury lamp (LH6fusion) at 520 mW / cm 2 and 220mJ / cm 2 UVA for UV light exposure.

[0560] Optical results

[0561] The polymer films were measured using the Axometrics Axostep, and each polymer film was measured twice, once with the film facing up (light source, substrate, polymer film, detector) and once with the film facing down (light source, polymer film, substrate, detector). The spectral polarization states are plotted on the Poincaré sphere, with the polarization ellipse varying with each wavelength, but each having a left-handed rotation. Due to the asymmetry of the twist in the z-direction, the film cannot be reversed.

[0562] To produce an achromatic circular polarizer, the back side (the side with less twist) of the polymer film is laminated with a linear polarizer, where the polarizer transmission axis makes an angle of 45° with the initial director of the aligned LC medium.

[0563] When light enters through the bottom of the polymer film, it first passes through the low-twist region. In this configuration, horizontally linearly polarized input light is converted to right-handed circularly polarized (RHCP) light, and it works equally well for all visible wavelengths.

[0564] When light enters through the top of the polymer film, it first passes through the high twist region. In this configuration, right-handed circularly polarized input light is converted to horizontally linearly polarized light, and this works equally well for all visible wavelengths.

[0565] Ray tracing is used to simulate the output polarization state selected for the input polarization state.

[0566] In the film-up measurement, ray tracing shows how horizontal input light is converted to RHCP output, and all spectral polarization states are tightly clustered at the +S3 pole of the Poincare sphere (S = [1, 0, 0, 1]).

[0567] In film-down measurements, ray tracing shows that the RHCP input light is converted to horizontal linearly polarized output, and the spectral polarization states are tightly concentrated at the +S1 (S=[1,1,0,0]) pole of the Poincare sphere.

[0568] Mueller matrix data measured with an Axometrics Axoscan have been used to model the progression of director orientation throughout the film. Figure 2 shown.

[0569] Anti-reflective visual performance

[0570] An antireflection stack S1 was created by arranging the polymer film of Example 1 between a reflective surface (eg a metal cathode of an OLED display) and a linear polarizer.

[0571] For comparison, reference antireflection stacks R1 and R2 were created as described above, but in the reference stack R1, the polymer film of Example 1 was replaced by a polymer film having a quarter-wavelength retardation and negative dispersion made of an H-type compound, and in the reference stack R2, the polymer film of Example 1 was replaced by a polymer film having a quarter-wavelength retardation but positive dispersion.

[0572] The anti-reflection performance of the three stacks was measured using DMS, as Figure 1 As shown, it can be seen that stack S1 comprising the polymer film of Example 1 shows the lowest reflectivity compared to reference stacks R1 and R2.

[0573] Example 2

[0574] Prepare mixtures RMM2 to RMM7 according to the following table:

[0575]

[0576]

[0577] SPI03 is a commercially available photoinitiator (Samyang, Korea)

[0578] TR-PBG-304 is a commercially available photoinitiator (Tronly, China)

[0579] N1919-T is a commercially available photoinitiator (Adeka Cooperation, Japan)

[0580] 651 is a commercially available photoinitiator (Ciba AG, Basel, Switzerland).

[0581] Polymer films were prepared from RMM2 to RMM7, and the optical results were measured as described in Example 1. All polymer films showed the expected chiral structure and had similar optical properties when measured on Axoscan.

[0582] This suggests that the type of photoinitiator is not critical to the mechanism of generating the desired chiral structure and that a variety of photoinitiators can be used.

Claims

1. A polymerizable LC medium comprising one or more di- or polyreactive mesogenic compounds, one or more chiral compounds having (S) configuration and further one or more chiral compounds having (R) configuration, wherein at least one of the chiral compounds having (S) configuration or the chiral compounds having (R) configuration is selected from photoreactive chiral compounds.

2. The polymerizable LC medium according to claim 1, wherein at least one of the chiral compound in (S) configuration or the chiral compound in (R) configuration is selected from polymerizable photoreactive chiral compounds.

3. A polymerisable LC medium according to claim 1 or 2, wherein the medium has a |HTP Δ | at 0.1 μm -1 Up to 100 μm -1 within the range.

4. Polymerizable LC medium according to one or more of claims 1 to 3, further comprising a photoinitiator.

5. A polymerisable LC medium according to claim 4, wherein the ratio of the concentration of photoinitiator to the total concentration of all chiral compounds is in the range from 1:1 to 1:

5.

6. A polymerisable LC medium according to one or more of claims 1 to 5, wherein the one or more di- or poly-reactive mesogenic compounds are selected from the group consisting of DRMs of the formula P 1 -Sp 1 -MG-Sp 2 -P 2 DRM in P 1 and P 2 independently of one another represent a polymerizable group, Sp 1 and Sp 2 are independently a spacer group or a single bond, and MG is a rod-shaped mesogenic group, which is preferably selected from the formula MG -(A 1 -Z 1 ) n -A 2 -MG in A 1 and A 2 represents, independently of one another on multiple occurrence, an aromatic or cycloaliphatic radical, which optionally contains one or more heteroatoms selected from N, O and S and is optionally mono- or polysubstituted by L, L is P-Sp-, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)NR x R y 、-C(=O)OR x 、-C(=O)R x 、-NR x R y , -OH, -SF5, optionally substituted silyl, aryl or heteroaryl having 1 to 12, preferably 1 to 6 C atoms, and linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12, preferably 1 to 6 C atoms, wherein one or more H atoms are optionally replaced by F or Cl, R x and R y independently of one another represent H or an alkyl radical having 1 to 12 C atoms, Z 1 In the case of multiple occurrences, it represents independently of one another -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O-COO-, -CO-NR x -、-NR x -CO-、-NR x -CO-NR y 、-NR x -CO-O-, -O-CO-NR x -, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH2CH2-, -(CH2) n1 , -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR x -、-CY 1 =CY 2 -, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond, preferably -COO-, -OCO- or a single bond, Y 1 and Y 2 independently of one another represent H, F, Cl or CN, n is 1, 2, 3 or 4, preferably 1 or 2, most preferably 2, n1 is an integer of 1 to 10, preferably 1, 2, 3 or 4.

7. Polymerizable LC medium according to one or more of claims 1 to 6, wherein the concentration of di- or polyreactive mesogenic compounds, preferably those of formula DRM and subformulae thereof, is preferably from 5 to 70%, very preferably from 10 to 60%, more preferably from 20 to 55%.

8. The polymerizable LC medium according to one or more of claims 1 to 7, comprising one or more monoreactive mesogenic compounds, preferably selected from compounds of the formula MRM: P 1 -Sp 1 -MG-R MRM Where P 1 、Sp 1 and MG has the meaning given to it in Formula DRM, R represents P-Sp-, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)NR x R y , -C(=O)X, -C(=O)OR x 、-C(=O)R y 、-NR x R y , -OH, -SF5, optionally substituted silyl, straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12, preferably 1 to 6 C atoms, wherein one or more H atoms are optionally replaced by F or Cl, X is halogen, preferably F or Cl, and R x and R y are independently H or alkyl having 1 to 12 C atoms.

9. The polymerizable LC medium according to one or more of claims 1 to 8, wherein the photoreactive chiral compound is selected from polymerizable photoreactive chiral compounds of formula I: P-(Sp-X) n -(A 1 -Z 1 ) m -G-(-Z 2 -A 2 -) l -R I in P is CH2=CW-COO-, WCH=CH-O- or CH2=CH-phenyl-(O) k -, wherein W is H, CH3 or F, Cl and k is 0 or 1, Sp is a spacer group having 1 to 20 C atoms, X is a group selected from -O-, -S-, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, or a single bond, n is 0 or 1, Z 1 and Z 2 each independently represents -COO-, -OCO-, -CH2CH2-, -OCH2-, -CH2O-, -CH=CH-, -CH=CH-COO-, -OCO-CH=CH-, -C≡C- or a single bond, A 1 and A 2 each independently 1,4-phenylene, where in addition one or more CH groups may be replaced by N, 1,4-cyclohexylene, where in addition one or two non-adjacent CH2 groups may be replaced by O and / or S, 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octanylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, all of which may be unsubstituted or mono- or polysubstituted by halogen, cyano or nitro or by alkyl, alkoxy or acyl groups having 1 to 7 C atoms, where one or more H atoms may be replaced by F or Cl, m and l are each independently 0, 1 or 2, G is the following structural element wherein q is 0, 1, 2, 3 or 4, and L is independently in each case halogen, cyano or nitro, or an alkyl, alkoxy or acyl group having 1 to 7 C atoms, wherein one or more H atoms may be substituted by F or Cl, and X is a photoreactive group, preferably a cinnamate group or an azo group, and R is alkyl with up to 25 C atoms, which may be unsubstituted, mono- or polysubstituted by halogen or CN, or one or more non-adjacent CH2 groups may be replaced, in each case independently of one another, by -O-, -S-, -NH-, -N(CH3)-, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S- or -C≡C- in such a way that the oxygen atoms are not directly attached to one another, or alternatively, R is halogen, cyano or independently has a radical P-(Sp-X) n - one of the meanings given.

10. The polymerizable LC medium according to one or more of claims 1 to 9, wherein the photoreactive chiral compound is selected from polymerizable photoreactive chiral compounds of formula Ia: wherein P, Sp, X, n, L, q and R have the meanings given in claim 9.

11. Polymerizable LC medium according to one or more of claims 1 to 10, comprising one or more monoreactive mesogenic compounds in a concentration of 1 to 80%, very preferably 5 to 70%, more preferably 10 to 60%.

12. Process for the production of a polymerizable LC medium according to one or more of claims 1 to 11, comprising at least the following steps: One or more di- or poly-reactive mesogenic compounds are mixed with one or more chiral compounds having an (S) configuration and one or more chiral compounds having an (R) configuration, wherein at least one of the chiral compounds comprises a photoisomerizable group.

13. Use of a polymerisable LC medium according to one or more of claims 1 to 11 for producing a polymer film exhibiting a biased helical pitch such that the chiral rotation angle gradually increases or decreases through the film thickness.

14. A method for preparing a polymer film, comprising the following steps: - providing a layer of a polymerisable LC medium according to one or more of claims 1 to 11 onto a substrate, the substrate optionally being provided with an alignment layer capable of inducing a planar alignment relative to an adjacent layer of the polymerisable LC medium, - a first step of irradiating the layer stack with actinic radiation in air, and - In a second step, in an inert gas atmosphere, the layer stack is irradiated with actinic radiation.

15. The method according to claim 14, characterized in that The irradiation with actinic radiation in the first and second steps is carried out by exposure to UV radiation.

16. The method according to claim 14 or 15, characterized in that The first and second irradiation or UV exposure steps are performed at room temperature and the layer of the polymerisable LC medium is not subjected to a heat treatment during or between the first and second irradiation or UV exposure steps.

17. Polymer film obtainable by a process according to one or more of claims 14 to 16.

18. The polymer film according to claim 17, characterized in that It exhibits an offset pitch, where the chiral rotation angle gradually increases or decreases through the film thickness.

19. Use of a polymer film according to claim 17 or 18 in an optical component.

20. A method for producing an optical component comprising the step of laminating the polymer film according to claim 17 or 18 onto a substrate or another polymer film.

21. An optical component comprising a polymer film according to claim 17 or 18.

22. The optical component according to claim 21, characterized in that It also contains the +A plate.

23. The optical component according to claim 21 or 22, characterized in that It is a QWP or anti-reflective component.

24. Use of a polymer film according to claim 17 or 18 or an optical component according to one or more of claims 21 to 23 in an optical or electro-optical device.

25. Optical or electro-optical device comprising a polymer film according to claim 17 or 18 or an optical component according to one or more of claims 21 to 23.

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