Polymerizable liquid crystal material and polymerized liquid crystal film

Abstract

The present invention relates to a polymerizable LC material comprising one or more reactive mesogenic compounds, one or more chiral compounds, and a block copolymer comprising at least one polyfluorooxetane block bonded to a polyether block, the polyfluorooxetane block having repeating units of the formula #imgabs0#, wherein the respective radicals have one of the meanings given in the claims. Furthermore, the present invention relates to a process for its preparation, a polymer film obtainable from the corresponding polymerizable LC material, a process for preparing such a polymer film, and the use of such a polymer film and the polymerizable LC material in optical, electro-optical, decorative, or security devices.

Description

Technical Field

[0001] The present invention relates to a polymerisable LC material comprising one or more reactive mesogenic compounds, one or more chiral compounds and a block copolymer comprising at least one polyfluorooxetane block in combination with a polyether block, said polyfluorooxetane block having repeating units of the formula

[0002]

[0003] wherein the respective radicals have one of the meanings given in the claims. Furthermore, the present invention relates to a process for their preparation, a polymer film obtainable from the corresponding polymerizable LC material, a process for preparing such a polymer film, and the use of such a polymer film and the polymerizable LC material in optical, electro-optical, decorative or security devices. Background Art

[0004] Reactive mesogens (RMs), mixtures or formulations containing them, and polymers obtained therefrom can be used to manufacture optical components such as compensation, retardation or polarizing films, or lenses. These optical components can be used in optical or electro-optical devices such as LC displays. Typically, the RMs or RM mixtures are polymerized by an in situ polymerization process.

[0005] Manufacturing RM film products with high birefringence is very important for manufacturing optical components of modern display devices such as LCDs. For example, brightness enhancement films (such as 3M DBEF TM ) are often included in displays to increase brightness or reduce the number of light sources in a backlight unit. Broadband cholesteric films can also be used for this purpose, and the optical properties depend on the broadening that can be achieved during processing. Films that are better able to broaden can be processed faster on the production line and may also have improved optical properties.

[0006] In this regard, the cholesteric reactive mesogen film can be polymerized such that a gradient in the helical pitch is obtained, thereby broadening the reflection band of the film.Thin films with good optical properties rely on the incorporation of at least one suitable high birefringence RM.

[0007] Cholesteric film broadening is determined by the high-birefringence material in the reactive mesogen mixture. The compound must be highly birefringent and allow band broadening to occur while also exhibiting good solubility and a broad nematic range, preferably without increasing the melting point too much. High-birefringence reactive mesogens produced to date with these characteristics have only allowed cholesteric film broadening to a certain extent before the film becomes hazy.

[0008] It is possible to increase the birefringence of RMs while keeping them polymerizable and having good physical properties, but this requires the incorporation of specific chemical groups into the compound, such as, for example, tolan groups.

[0009] Mesogenic tolan derivatives are known, for example, from US 6,514,578 B1, GB 2 388 599 B1, US 7,597,942 B1, US 2003-072893 A1 and US 2006-0119783 A1.

[0010] Typically, the tolan group is relatively reactive and generally not amenable to light exposure, making it difficult to use in many optical applications due to yellowing or other degradation effects. Furthermore, mesogenic tolan derivatives generally exhibit limited solubility in RM mixtures and are therefore limited in their use.

[0011] Furthermore, cholesteric liquid crystal (CLC) materials, when formed into thin layers with a planar alignment (i.e., in which the cholesteric helical axes are oriented substantially perpendicular to the plane of the layer), exhibit the well-known effect of selective reflection of light, where the wavelength of the reflected light depends on the pitch of the cholesteric helices. By using polymerizable CLC materials, the aligned CLC layer can be converted into a coherent polymer film that retains the selective reflection properties of the original material.

[0012] CLC polymer films are known in the prior art and have been proposed for various uses, for example as broadband or notch polarizers, as color filters in displays or projection systems, and for decorative and security purposes, such as the preparation of color image films or cholesteric pigment flakes.

[0013] For some applications, it is desirable to form a multilayer cholesteric film comprising two or more cholesteric layers, eg, exhibiting different reflection wavelengths.

[0014] Multilayer cholesteric polymer films have been described in the prior art, for example US 6,417,902. Furthermore, EP 0 634 674 suggests preparing a multilayer cholesteric liquid crystal polymer film by bonding a pair of chiral nematic liquid crystal polymer films together, applying pressure and heating the polymers above their glass transition temperature to allow the films to adhere.

[0015] Maurer et al., SID 90 Digest, Vol. 21, pp. 110 (1990) describe polarizing color filters obtained by combining several polarizing films with different reflection wavelengths. To prepare each film, a layer of a CLC-side chain polysiloxane containing chiral and achiral side groups is placed between two glass plates and oriented by shearing at high temperature.

[0016] JP 01-133003-A (Sumi tomo Chem. Ind.) and JP 08-271731-A (Nit to Denko) disclose polarizing plates obtained by laminating one or more CLC polymer layers onto a quarter wave plate.

[0017] However, the methods described in the aforementioned documents for producing multilayer cholesteric films have several disadvantages. Consequently, achieving uniform alignment in the CLC polymer layer is often very difficult and requires high temperatures. For example, Maurer et al. mention an alignment temperature of 150°C, while JP01-133003-A and JP08-271731-A mention the need for temperatures well above the glass transition temperature of the CLC polymer. This is particularly disadvantageous when using polymers with high glass transition temperatures (such as acrylates, styrenes, or methacrylates), and is particularly unsuitable for large-scale production.

[0018] Furthermore, according to the multilayer production method described, for example, in JP01-133003-A, polymers must be selected so that different polymer layers exhibit different glass transition temperatures. Consequently, when, for example, a second layer is laminated and aligned on top of the first layer, the alignment temperature (and therefore the glass transition temperature) of the second layer must be lower than the glass transition temperature of the first layer in order not to affect the uniform orientation of the first layer. This severely limits the selection of suitable materials and complicates the production process.

[0019] Another aspect is that polymerizable LC materials often need to include a leveling agent (e.g., a surfactant) in order to achieve good alignment of the resulting CLC polymer. Typically, without the use of a surfactant in the formulation, increased haze, poor alignment of the helices in the CLC polymer, and uneven thickness across the film can be observed. Furthermore, due to the leveling agents typically used in such formulations, achieving good alignment and coating quality of the second coating of the CLC material required for multilayer applications can be difficult.

[0020] In this context, dewetting is defined as the breaking up of a thin liquid film on a substrate and the formation of droplets. In the case of multilayer applications, this can lead to an uneven thickness of the second CLC material upon drying. In some cases, the film can retract from the edges, and in the worst case, there is extreme beading of the second coating layer, which results in zero coverage of the coated area.

[0021] The object of the present invention is therefore to provide improved polymerizable LC materials or RM mixtures and RM formulations that do not exhibit the disadvantages of the materials known in the prior art. In particular, the object is to provide RM mixtures and RM formulations that are suitable for the preparation of polymers by in situ UV photopolymerization and that simultaneously exhibit high birefringence, good solubility, improved broadening potential, a favorable transition temperature, and high resistance to yellowing after exposure to UV light. Another object is to provide an improved multilayer stack that does not exhibit the disadvantages of the materials known in the prior art. Further objects of the invention will be immediately apparent to the expert from the following description.

[0022] Surprisingly, the inventors of the present invention have found that a polymerisable LC material according to claim 1 fulfils one or more of the requirements defined above and preferably achieves all objects simultaneously. Summary of the Invention

[0023] The present invention relates to a polymerisable LC material comprising one or more reactive mesogenic compounds, one or more chiral compounds and a block copolymer comprising at least one polyfluorooxetane block bonded to a polyether block, wherein the polyfluorooxetane block has a repeating unit of the formula

[0024]

[0025] Each of them

[0026] n and m are each and independently an integer from 1 to 6,

[0027] R is hydrogen or an alkyl group having 1 to 6 carbon atoms,

[0028] Rf and R f* Each and independently a straight or branched chain alkyl group of 1 to about 20 carbon atoms, wherein said R f or R f* at least 50% of the hydrogen atoms of the alkyl group are replaced by F, and optionally up to all remaining H atoms are replaced by I, Cl or Br,

[0029] DP is 2 to about 100.

[0030] Furthermore, the present invention also relates to a corresponding production process for a polymerisable LC material, comprising at least the step of mixing one or more reactive mesogenic compounds, one or more chiral mesogenic compounds and a block copolymer.

[0031] The present invention also relates to a polymer network or polymer film obtainable, preferably obtainable, from a polymerisable LC material as described above and below, and to a method for the preparation of a polymer film as described above and below.

[0032] The present invention also relates to a method for improving the dewetting behavior of a polymer film obtainable from a polymerizable LC material as described above and below, preferably obtained from a polymerizable LC material as described above and below, by adding a block copolymer as described above and below to the polymerizable LC material before polymerization.

[0033] The present invention also relates to an optical component comprising one or more optical films, wherein one optical film is selected from polymer films obtainable from polymerisable LC materials as described above and below.

[0034] The present invention also relates to the use of an optical component or a polymer film or a polymerizable LC material as described above and below in optical, electrooptical, information storage, decorative and security applications, such as liquid crystal displays, projection systems, polarizers, compensators, alignment layers, circular polarizers, color filters, decorative images, liquid crystal pigments, reflective films with spatially different reflection colors, multicolor images, unforgeable documents such as identity cards or credit cards or banknotes.

[0035] The invention also relates to an electro-optical device, such as an LCD or an OLED, comprising one or more optical components or polymer films or polymerisable LC materials as described above and below.

[0036] The invention also relates to electro-optical devices in the field of augmented or virtual reality, such as head-mounted devices comprising one or more optical components, polymer films of polymerizable materials as described above and below.

[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," and the like. Furthermore, it should be understood that the term polymer encompasses, 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. Furthermore, such residues and other elements, while typically removed during post-polymerization purification, are typically mixed or blended with the polymer so that they typically remain in the polymer when it 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 (LC) refers to materials that have a liquid crystal mesophase within a certain temperature range (thermotropic LC) or within a certain concentration range in solution (lyotropic LC). They necessarily contain mesogenic compounds.

[0043] The terms "mesogenic compound" and "liquid crystal compound" refer to compounds containing 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 that has the ability to induce liquid crystal phase (or mesophase) behavior. Compounds containing mesogenic groups do not necessarily exhibit liquid crystal mesophases themselves. They can also exhibit liquid crystal mesophases only in mixtures with other compounds or when the mesogenic compound or material or mixtures thereof are polymerized. Such liquid crystal mesophases include low molecular weight non-reactive liquid crystal compounds, reactive or polymerizable liquid crystal compounds, and liquid crystal polymers.

[0044] The rod-shaped 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 end groups attached to the ends of the mesogenic core, and optionally comprising one or more side groups attached to the long sides 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.

[0045] The term "reactive mesogen" refers to polymerizable mesogenic or liquid crystal compounds, preferably monomeric compounds. These compounds can be used as pure compounds or as mixtures of reactive mesogens with other compounds that act as photoinitiators, inhibitors, surfactants, stabilizers, chain transfer agents, non-polymerizable compounds, etc.

[0046] Polymerizable compounds with one polymerizable group are also referred to as "monoreactive" compounds, compounds with two polymerizable groups are also referred to as "direactive" compounds, and compounds with more than two polymerizable groups are also referred to as "polyreactive" compounds. Compounds that do not contain polymerizable groups are also referred to as "non-reactive or non-polymerizable" compounds.

[0047] The term "non-mesogenic compound or material" refers to a compound or material that does not contain a mesogenic group as defined above.

[0048] 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.

[0049] Irradiance (E e ) or radiant power is defined as the power of electromagnetic radiation (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 radiation power (E e ):

[0052] H e =E e ·t.

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

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

[0055] 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 a liquid crystal or RM molecule. In the case of uniaxial ordering of such anisotropic molecules, the director is the anisotropy axis.

[0056] The term "alignment" or "orientation" refers to the alignment (orientational ordering) of anisotropic units of a material (e.g., small molecules or fragments of a macromolecule) along a consistent direction (called the "alignment direction"). In a liquid crystal material or an alignment layer of a RM material, the liquid crystal director is aligned with the alignment direction so that the alignment direction corresponds to the direction of the anisotropy axis of the material.

[0057] The term "homogeneous orientation" or "homogeneous alignment" of a liquid crystal or RM material, for example in a layer of the material, means that the long molecular axes (in the case of rod-shaped compounds) or the short molecular axes (in the case of discotic compounds) of the liquid crystal or RM molecules are essentially aligned in the same direction. In other words, the lines of the liquid crystal directors are parallel.

[0058] The term "homeotropic structure" or "homeotropic orientation" refers to a film in which the optical axis is substantially perpendicular to the plane of the film.

[0059] The terms "planar structure" or "planar orientation" refer to films in which the optical axis is substantially parallel to the plane of the film.

[0060] The term "A-plate" refers to an optical retarder that utilizes a layer of uniaxial birefringent material with its extraordinary axis oriented parallel to the plane of the layer.

[0061] The term "C-plate" refers to an optical retarder that utilizes a layer of uniaxial birefringent material with its extraordinary axis oriented perpendicular to the plane of the layer.

[0062] In an A / C-plate containing an optically uniaxially birefringent liquid crystal material having a uniform orientation, the optical axis of the film is given by the direction of the extraordinary axis. An A (or C) plate containing an optically uniaxially birefringent material having a positive birefringence is also referred to as a "positive A (or C) plate" or "+A (or +C) plate".

[0063] A (or C) plates comprising films of optically uniaxially birefringent materials having negative birefringence, such as discotic anisotropic materials, are also referred to as "negative A (or C) plates" or "-A (or C) plates," depending on the orientation of the discotic material. Films made of cholesteric rod-shaped materials having a reflection band in the UV portion of the spectrum also have the optics of a negative C plate.

[0064] The birefringence Δn is defined as follows

[0065] △n=n e -n o

[0066] where n e is the extraordinary refractive index and n o is the ordinary refractive index, and the average effective refractive index n av. is given by the following equation:

[0067] n av. =((2n o 2 +n e 2 ) / 3) 1 / 2

[0068] Average effective refractive index n av. and ordinary refractive index no It can be measured using an Abbe refractometer. Δn can then be calculated from the above equation.

[0069] 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.

[0070] Unless explicitly stated otherwise, all physical properties have been measured according to or in accordance with “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, 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.

[0071] In case of doubt, the definitions as given in C. Tschierske, G. Pelzl and S. Diele, Angew. Chem. 2004, 116, 6340-6368 shall apply.

[0072] Unless otherwise indicated, in the given formulae, the following terms have the following meanings:

[0073] "Carbyl" refers to a monovalent or polyvalent organic group containing one or more carbon atoms, 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.). "Hydrocarbyl" refers to a carbon group that 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.

[0074] The carbyl or hydrocarbyl 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 hydrocarbyl group having more than 3 C atoms may be straight-chain, branched and / or cyclic and may contain spiro-connected or fused rings.

[0075] Preferred carbon and hydrocarbon radicals are optionally substituted alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy radicals having 1 to 40 C atoms, preferably 1 to 25 C atoms, particularly preferably 1 to 18 C atoms, optionally substituted aryl or aryloxy radicals having 6 to 40 C atoms, preferably 6 to 25 C atoms, or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy radicals having 6 to 40 C atoms, preferably 6 to 25 C atoms.

[0076] Other preferred carbon and hydrocarbon groups are C1-C 40 Alkyl, C2-C 40 Alkenyl, C2-C 40 Alkynyl, C3-C 40 Allyl, C4-C 40 Alkyldiene, C4-C 40 Polyene, C6-C 40 Aryl, C6-C 40 Alkyl aryl, C6-C 40 Arylalkyl, C6-C 40 Alkyl aryloxy, C6-C 40 Arylalkyloxy, C2-C 40 Heteroaryl, C4-C 40 Cycloalkyl, C4-C 40 Cycloalkenyl, etc. Particularly preferred are C1-C 22 Alkyl, C2-C 22 Alkenyl, C2-C 22 Alkynyl, C3-C 22 Allyl, C4-C 22 Alkyldiene, C6-C 12 Aryl, C6-C 20 Arylalkyl and C2-C 20 Heteroaryl.

[0077] Other preferred carbon and hydrocarbon radicals are linear, 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 CH2 groups can each be replaced independently of one another by -C(R x )=C(R x )-,-C≡C-,-N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- are substituted in such a way that the O and / or S atoms are not directly bonded to each other.

[0078] In the above, R x Preferably it denotes H, halogen, a linear, 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.

[0079] 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, etc., wherein, in addition, one or more non-adjacent CH2 groups may each independently be replaced by Alternative.

[0080] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl and the like.

[0081] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl and the like.

[0082] 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, etc., wherein, in addition, one or more non-adjacent CH2 groups may each independently be replaced by Alternative.

[0083] Preferred amino groups include dimethylamino, methylamino, methylphenylamino, and phenylamino.

[0084] 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.

[0085] Preference is given to monocyclic, bicyclic or tricyclic aryl radicals having 6 to 25 C atoms and monocyclic, bicyclic or tricyclic heteroaryl radicals having 2 to 25 C atoms, which optionally contain fused rings and which are optionally substituted. Furthermore, preference is given to 5-, 6- or 7-membered aryl and heteroaryl radicals, in which one or more CH groups may be replaced by N, S or O in such a way that the O atoms and / or S atoms are not directly connected to one another.

[0086] 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, etc.

[0087] 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, pyrazinimidazole, quinoxalinoimidazole, 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 thereof. The heteroaryl group may also be substituted with an alkyl, alkoxy, sulfanyl, fluorine, fluoroalkyl, or other aryl or heteroaryl groups.

[0088] (Non-aromatic) alicyclic 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.

[0089] (Non-aromatic) alicyclic group and heterocyclic group can be monocyclic, i.e. only contain one ring (for example cyclohexane), or be polycyclic, i.e. contain multiple rings (for example decalin or bicyclooctane).Particularly preferred are saturated groups.In addition preferably have 3-25 atom's single-, two- or three-cyclic groups, it optionally contains fused ring and it is optional replacement.Further preferred are 5-, 6-, 7- or 8-unit carbocyclic groups, wherein in addition, one or more C atoms can be substituted by Si and / or one or more CH groups can be substituted by N and / or one or more non-adjacent CH2 groups can be substituted by-O- and / or-S-.

[0090] 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.

[0091] Aryl, heteroaryl, (non-aromatic) alicyclic and heterocyclic groups optionally have one or more substituents, preferably selected from silyl, sulfonic acid, sulfonyl, formyl, amine, imine, nitrile, mercapto, nitro, halogen, C 1-12 Alkyl, C 6-12 Aryl, C 1-12 alkoxy, hydroxy or a combination of these groups.

[0092] 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 for increasing the glass transition temperature (Tg) of the polymer, particularly bulky groups, such as tert-butyl or optionally substituted aryl groups.

[0093] Preferred substituents (hereinafter also referred to as "L") are, for example, F, Cl, Br, I, OH, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )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.

[0094] "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 yOR-O-CO-OR y Substituted, where R y represents H, a linear, branched or cyclic alkyl chain having 1 to 12 C atoms.

[0095] In the formulae shown above and below, the substituted phenylene ring

[0096] Preferably

[0097]

[0098] wherein L has, identically or differently on each occurrence, one of the meanings given above and below and is preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, OCH3, COCH3, OCF3 or P-Sp-, most preferably F, Cl, CH3, OCH3, COCH3 or OCF3.

[0099] "Halogen" means F, Cl, Br or I, preferably F or Cl, more preferably F.

[0100] 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, oxetane or epoxy groups.

[0101] Preferably, the polymerizable group (P) is selected from CH2=CW 1 -COO-, CH2=CW 1 -CO-, CH2=CW 2 -(O) k3 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O)k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-,

[0102] in

[0103] W 1 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3,

[0104] W 2 represents H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl,

[0105] 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, preferred substituents L are F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, and also phenyl, and

[0106] k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 is an integer of 1 to 10.

[0107] Particularly preferred polymerizable groups P are CH2=CH-COO-, CH2=C(CH3)-COO-, CH2=CF-COO-, CH2=CH-, CH2=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH)2CH-O-, Where W 2 represents H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl.

[0108] Further preferred polymerizable groups (P) are vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy groups, most preferably acrylate or methacrylate, especially acrylate.

[0109] Preferably, all polyreactive polymerizable compounds and subformulae thereof comprise one or more branching groups comprising two or more polymerizable groups P (polyreactive polymerizable groups) instead of one or more groups P-Sp-.

[0110] 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.

[0111] Particularly preferred are polyreactive polymerizable groups selected from the following formulae

[0112] -X-alkyl-CHP x -CH2-CH2P y I*a

[0113] -X-alkyl-C(CH2P x )(CH2P y )-CH2P z I*b

[0114] -X-alkyl-CHP x CHP y -CH2P z I*c

[0115] -X-alkyl-C(CH2P x )(CH2P y )-C aa H 2aa+1 I*d

[0116] -X-alkyl-CHP x -CH2P y I*e

[0117] -X-alkyl-CHP x P y I*f

[0118] -X-alkyl-CP x P y -C aa H 2aa+1 I*g

[0119] -X-alkyl-C(CH2P v )(CH2P w )-CH2OCH2-C(CH2P x )(CH2Py)CH2P z I*h

[0120] -X-alkyl-CH((CH2) aa P x )((CH2) bb P y )I*i

[0121] -X-alkyl-CHP x CHPy -C aa H 2aa+1 I*k

[0122] in

[0123] Alkyl represents a single bond or a straight-chain or branched alkylene radical having 1 to 12 C atoms, wherein one or more non-adjacent CH2 groups may each be replaced independently of one another 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 one another, and in addition wherein one or more H atoms may be replaced by F, Cl or CN, wherein R x has one of the meanings mentioned above,

[0124] aa and bb each independently represent 0, 1, 2, 3, 4, 5 or 6,

[0125] X has one of the meanings indicated for X', and

[0126] P v To P z Each independently of the others has one of the meanings indicated above for P.

[0127] Preferred spacer groups Sp are selected from alkylene groups having 1 to 20, preferably 1 to 12, C atoms, which are optionally mono- or polysubstituted by F, Cl, Br, I or CN and wherein, in addition, one or more non-adjacent CH2 groups may each be substituted independently of one another 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 0xx -,-NR xx -CO-NR yy -, -CH=CH- or -C≡C- are substituted in such a way that the O and / or S atoms are not directly connected to each other, and wherein R xx and R yy Each independently of one another represents H or alkyl having 1 to 12 C atoms.

[0128] Further 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

[0129] Sp' represents an alkylene radical 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 wherein, moreover, one or more non-adjacent CH2 groups may each independently of one another be 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 0xx -,-NR xx -CO-NR yy -, -CH=CH- or -C≡C- are substituted in such a way that the O and / or S atoms are not directly connected to each other,

[0130] X' represents -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR xx -,-NR xx -CO-, -NR xx -CO-NR yy -, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR xx -,-CY xx =CY xx -, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or single bond,

[0131] R xx and R yy each independently of one another represents H or an alkyl group having 1 to 12 C atoms, and

[0132] Y xx and Y yy Each independently represents H, F, Cl or CN.

[0133] X' is preferably -O-, -S--CO-, -COO-, -OCO-, -O-COO-, -CO-NR xx -、-NR xx -CO-、-NR xx -CO-NR yy - or single key.

[0134] Typical and preferred spacer groups Sp and / or Sp' are, for example, -(CH2) p1-, -(CH2CH2O) q1 -CH2CH2-, -CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2-or-(SiR xx R yy -O) p1 -,

[0135] 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 meanings set out above.

[0136] A particularly preferred group -X'-Sp'- is -(CH2) p1 -, -O-(CH2) p1 -, -OCO-(CH2) p1 -,-OCOO-(CH2) p1 -, wherein p1 is an integer from 1 to 12.

[0137] Particularly preferred radicals Sp and / or 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.

[0138] Often, the term "chiral" is used to describe an object that is non-superimposable on its mirror image.

[0139] An "achiral" (without hand) object is one that is identical to its mirror image.

[0140] Unless explicitly stated otherwise, the terms "chiral nematic" and "cholesteric" are used synonymously in this application.

[0141] Chiral nematic textures or cholesteric liquid crystals (CLCs) exhibit selective reflection of circularly polarized light, where the direction of rotation of the light vector corresponds to the direction of rotation of the cholesteric helix.

[0142] The reflection wavelength λ is given by the pitch P of the cholesteric helix and the average birefringence n of the cholesteric liquid crystal according to the following equation:

[0143] λ=n·p

[0144] CLC media can be prepared, for example, by doping nematic LC media with chiral dopants having high twisting power. The pitch p of the induced cholesteric helix is ​​then provided by the concentration c of the chiral dopant and the twisting power HTP according to the following equation:

[0145] p=(HTP c) -1

[0146] It is also possible to use two or more dopants, for example to compensate for the temperature dependence of the HTP of the individual dopants and thus to achieve a low temperature dependence of the helical pitch and the reflection wavelength of the CLC medium. 总 ), then the following equation applies approximately:

[0147] HTP total =∑ i c i HTP i

[0148] where c i is the concentration of each individual dopant and HTP i is the helical twisting force of each individual dopant.

[0149] For the present invention,

[0150]

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

[0152]

[0153] represents 1,4-phenylene.

[0154] For the purposes of the present invention, the group -COO- or -CO2- is represented by the formula The ester group, and the group -OCO-, -O2C- or -OOC- are expressed as ester group.

[0155] A "polymer network" is a network in which all polymer chains are interconnected by numerous crosslinks to form a single macroscopic entity. Polymer networks can occur in the following types:

[0156] A grafted polymer molecule is a branched polymer molecule in which one or more side chains differ structurally or conformationally from the main chain.

[0157] A star polymer molecule is a branched polymer molecule in which a single branch point gives rise to multiple linear chains or arms. If the arms are identical, the star polymer molecule is said to be regular. If adjacent arms are composed of different repeating subunits, the star polymer molecule is said to be diversified.

[0158] A comb polymer molecule consists of a main chain with two or more three-way branching points and linear side chains. If the arms are identical, the comb polymer molecule is called regular.

[0159] - Brush polymer molecules consist of a backbone with linear, unbranched side chains, and where one or more of the branching points has a four-way functionality or greater.

[0160] Throughout the description and claims of this specification, the words "include" and "contain" and variations of the words (e.g., "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."

[0161] Throughout the description and claims of this specification, the wording "obtainable" and "obtained" and variations of the wording mean "including but not limited to", and are not intended to (and do not) exclude other components. On the other hand, the wording "obtainable" also encompasses but is not limited to the term "obtained".

[0162] All concentrations are quoted in weight percent and relate to the respective mixture as a whole, all temperatures are quoted in degrees Celsius and all temperature differences are quoted in differential degrees. DETAILED DESCRIPTION

[0163] Preferred are block copolymers wherein the DP is in the range of at least 2 to about 100 or 200, more preferably 2 to about 10 or 20, or 30, even more preferably 2 to 6.

[0164] Preferred are block copolymers wherein the polyfluorooxetane block is an oligomer, polymer or copolymer.

[0165] Further preferred are block copolymers wherein each Rf or R f* The total amount of fluorine atoms in the group is typically at least 10% or 25%, ideally at least 50% or 75%, preferably at least 80%, 85%, 90% or 95%, or even 100% (perfluorinated), e.g., trifluoromethyl, pentafluoroethyl, heptafluoropropyl, etc., and any remaining non-carbon or non-fluorine atoms are H, or I, or Cl or Br.

[0166] Pendant or side chain group R f or R f* It may be present on all monomers (including polymers), or on a selected minority, preferably in the range of about 50% to 100% of the monomers containing pendant or side chain groups R f or R f* The monomer of the polymer.

[0167] Preferred polymers contain one R per repeat unit. f group and does not contain group Rf* Therefore, the following repeating units are preferred,

[0168] Preferably, n represents an integer from 1 to 6, preferably 1, 2, 3 or 4.

[0169] On each monomer R f independently represents a linear or branched, unsaturated, or preferably saturated alkyl group having from 1 to about 7, or about 10, or about 15, or about 20 carbon atoms, of which at least 25, 50, 75, 80, 85, 90 or 95%, or preferably 100%, of said R f of the H atoms are replaced by F, and optionally up to all remaining H atoms are replaced by I, Cl or Br.

[0170] When R f When short chain, it preferably contains 1, 2, 3 or 4 carbon atoms. f It may contain a straight chain alkyl group or a branched chain alkyl group, preferably a straight chain alkyl group.

[0171] When it is a branched group, the main chain contains from 1 to 7 carbon atoms, and each branch may also contain up to 3 carbon atoms.

[0172] R is hydrogen or an alkyl group of 1 to 6 carbon atoms, preferably a methyl group or an ethyl group, more preferably a methyl group.

[0173] Suitable polyethers include hydroxy-terminated polyethylene glycol, polypropylene glycol, polybutylene glycol, polyisobutylene glycol, etc. and their monohydroxy compounds, such as polyethylene glycol methyl ether, polytetramethylene glycol, etc. Preferably, the polyether is neopentyl glycol.

[0174] Such polyethers generally have an average molecular weight of from about 50 to about 10,000, desirably from about 75 to about 5,000, preferably from about 100 to about 2,500, and thus can be monomers, oligomers, polymers, or copolymers.

[0175] Preferably, the block copolymer is an AB, or BAB, or BA, or ABA block copolymer, wherein the A block is the polyether block and the B block is the polyfluorooxetane block.

[0176] Block copolymers of polyfluorooxetane and polyether can be prepared according to two different approaches. In one approach, the polyether acts as an initiator for reaction with the fluorooxetane monomer; or alternatively, the fluorooxetane oligomer, polymer or copolymer acts as an initiator for reaction with the alkylene oxide monomer in the presence of a catalyst to form polyfluorooxetane blocks bound or linked to the polyether, or alternatively to form polyether blocks linked to the fluorooxetane oligomer, polymer or copolymer.

[0177] The polyethers used as initiators can be prepared in a manner known in the literature and in the art. One common source is an alkylene oxide monomer containing from 2 to about 6 carbon atoms, and preferably from 2 to about 4 carbon atoms.

[0178] Fluoroxetane monomers are those described in 2003 / 0109662A1, which is incorporated herein by reference in its entirety.

[0179] The polymerization of one or more fluorooxetane monomers initiated by one or more polyether functional groups, such as hydroxyl groups, is ideally carried out by solution polymerization and is therefore carried out in the presence of a solvent. Suitable solvents are generally polar and / or halogenated hydrocarbons having a total of 1 to about 6 carbon atoms, such as dichloromethane, carbon tetrachloride, chloroform, trichloroethylene, chlorobenzene, ethyl bromide, dichloroethane, and the like, preferably dichloromethane.

[0180] The amount of such solvents is generally from about 50 to about 100 parts by weight, and desirably from about 50 to about 65 parts by weight, per 100 parts by weight of the combined weight of the polyether initiator and the one or more fluorooxetane monomers.

[0181] One or more fluorooxetane monomers that are polymerized on the polyether initiator with 1 or more functional groups (for example hydroxyl) are easy to polymerization in the presence of a Lewis acid catalyst (that is, the compound that can accept an electron pair).This suitable Lewis acid comprises the complex compound of boron trifluoride, for example BF etherate, BF -THF, antimony pentafluoride, zinc chloride, aluminum bromide etc., wherein BF -THF is preferred.When using BF -THF, THF will be polymerized, therefore will produce fluorooxetane-THF copolymer.Usually, based on the gross weight of copolymer, the amount of THF in the copolymer is approximately 0.05 % by weight to approximately 10 % by weight or approximately 12 % by weight or approximately 30 % by weight or approximately 50 % by weight, and is ideally approximately 0.1 % by weight to approximately 5 % by weight.

[0182] The polymerization is carried out at a temperature of about 15°C to 1 or 2 degrees below the boiling point of the solvent, ideally about 25°C to about 45°C, preferably about 35°C to about 40°C. The polymerization time may vary depending on the temperature and other factors, but generally ranges from about 1 / 2 to about 5 hours. Once the various fluorooxetane monomers have been polymerized onto the polyether, the final product, which is a block copolymer, can be washed with water to remove the solvent.

[0183] If the polyether initiator has one functional end group, such as a hydroxyl group, an AB block copolymer will be formed, wherein the B block is derived from a fluorooxetane monomer and the A block is derived from a monohydroxy polyether. Alternatively, if the polyether has two functional end groups, a BAB block copolymer will be formed. In either case, the B block will have a hydroxyl end group.

[0184] Including a block copolymer as described above and below in the polymerisable LC material allows for easy formation of aligned CLC phases with no visible haze, while also allowing another layer to be coated on top which provides good alignment without the need for a second alignment layer.

[0185] This choice of block copolymer type also eliminates any issues with dewetting of upper layers in a layer stack, which is common when using surfactant additives.

[0186] The concentration of the block copolymer as described above and below in the polymerisable LC material is preferably from 0.01% to 1%, more preferably from 0.03% to 0.7%, especially from 0.05% to 0.5%.

[0187] The block copolymers as described above and below can advantageously and preferably be prepared according to the disclosure given in 2003 / 0109662 A1 or as A series of additives are commercially available from Omnova Solutions Inc., USA, such as PF-636, PF-6320, PF-656, PF-650, or PF-7002:

[0188]

[0189] x + y = 4 or 5

[0190] Polyfox TM PF-7002

[0191] In a preferred embodiment, the polymerisable LC material comprises one or more reactive mesogens selected from the group consisting of formula RMT,

[0192]

[0193] P is a polymerizable group,

[0194] Sp is a spacer group or a single bond,

[0195] r2 and r3 are independently 0, 1, 2, 3 or 4,

[0196] R 11 is P-Sp-, alkyl, alkoxy, thioalkyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, preferably having 1 to 15 C atoms, which is more preferably optionally fluorinated.

[0197] A and B, in the case of multiple occurrences, independently of one another, denote 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, preferably 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 CH2 groups are optionally replaced by O and / or S, where these radicals are unsubstituted or substituted by 1, 2, 3 or 4 radicals L,

[0198] 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, or a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 12 C atoms, wherein one or more H atoms are optionally replaced by F or Cl, preferably F, -CN or a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 6 C atoms,

[0199] R x and R y independently of one another represent H or an alkyl group having 1 to 12 C atoms,

[0200] Z 11 and Z 12 In the case of multiple occurrences, -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O-COO-, -CO-NR are independently of one another. 00 -,-NR 00 -CO-, -NR 00 -CO-NR 000 , -NR 00 -CO-O-, -O-CO-NR 00 -, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH2CH2-, -(CH2) n1 , -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 00-,-CY 1 =CY 2 -, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond, preferably -COO-, -OCO-, -C≡C-, or a single bond,

[0201] Y 1 and Y 2 independently represent H, F, Cl or CN,

[0202] n is 1, 2, 3 or 4, preferably 1 or 2, most preferably 1,

[0203] m is 0, 1, 2, 3 or 4, preferably 0 or 1, most preferably 0,

[0204] n1 is an integer from 1 to 10, preferably 1, 2, 3 or 4.

[0205] Preferred compounds of formula RMT are selected from those of formula RMTa or RMTb,

[0206]

[0207]

[0208] in

[0209] P is a polymerizable group,

[0210] Sp is a spacer group or a single bond,

[0211] r1, r2, r3 are independently 0, 1, 2, 3 or 4, preferably 0, 1 or 2 and L, R 11 , Z 12 , Ring B and m have one of the meanings given above under formula RMT.

[0212] Preferred compounds of formula RMTa are selected from those of formula RMTa1 to RMTa6

[0213]

[0214] Among them, L, P, Sp, and R 11 As defined in formula RMT, r1 to r3 represent 1, 2, 3, or 4, preferably 1 or 2.

[0215] Preferred compounds of formula RMTa1 to RMTa6 are selected from the following formula

[0216]

[0217]

[0218] Among them, P 11represents a group selected from the group consisting of heptadiene, vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy groups, and very preferably represents an acrylate, methacrylate or oxetane group, especially an acrylate or methacrylate group, in particular an acrylate group, and x is an integer from 0 to 12, preferably from 1 to 8, more preferably 3, 4, 5 or 6, in particular x represents 3 or 6, in particular 6, and R 11 represents alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, preferably having 1 to 15 C atoms, which is more preferably optionally fluorinated and L has on each occurrence one of the meanings given above for the formula RMT.

[0219] Especially preferred are compounds of formula RMTa2, which are preferably selected from the following formulae:

[0220]

[0221]

[0222]

[0223] where R 11 has one of the meanings given above under formula RMT, preferably R 11 represents an alkyl group or an alkoxy group, more preferably a methoxy group, an ethoxy group, a propoxy group, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an isopropyl group or an isobutyl group, in particular a methoxy group.

[0224] Preferred compounds of formula RMTb are those selected from formulae RMTb0 to RMTb6

[0225]

[0226] Among them, L, P, Sp, and R 11 As defined in formula RMT, r1 to r3 represent 1, 2, 3, or 4, preferably 1 or 2.

[0227] Preferred compounds of formula RMTb0 to RMTb6 are selected from the following formula

[0228]

[0229]

[0230]

[0231] Among them, P 11represents a group selected from the group consisting of heptadiene, vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy groups, and very preferably represents an acrylate, methacrylate or oxetane group, especially an acrylate or methacrylate group, in particular an acrylate group, and x is an integer from 0 to 12, preferably from 1 to 8, more preferably 3, 4, 5 or 6, in particular x represents 3 or 6, in particular 6, and R 11 represents alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, preferably having 1 to 15 C atoms, which is more preferably optionally fluorinated and L has on each occurrence one of the meanings given above for the formula RMT.

[0232] Especially preferred are compounds of formula RMTb2, which are preferably selected from the following formulae:

[0233]

[0234]

[0235]

[0236] where R 11 has one of the meanings given above under formula RMT. 11 represents an alkyl group or an alkoxy group.

[0237] Further preferred are compounds of formula RMTb2-A1 selected from compounds of the formula,

[0238]

[0239]

[0240]

[0241] where R 11 has one of the meanings given above under formula RMT, preferably R 11 represents an alkyl group or an alkoxy group, more preferably a methoxy group, an ethoxy group, a propoxy group, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an isopropyl group or an isobutyl group, in particular a methoxy group.

[0242] Preferably, the polymerisable LC material comprises one or more, preferably two or more, compounds selected from formulae RMTa2-A3 to RMTa2-A6 or RMTb2-A3, in particular the polymerisable LC material comprises one or more compounds of formula RMTb2-A3, in particular the polymerisable LC material comprises a combination of compounds of formulae RMTa2-A4 and / or RMTa2-A5 and RMTb2-A3.

[0243] By using one or more compounds of formula RMT in the polymerizable LC material, the birefringence of the polymer film can be advantageously increased. The corresponding reflection bandwidth is related to the birefringence by the following formula:

[0244] Bandwidth = △n*pitch,

[0245] It can be seen that by increasing the birefringence of the cholesteric polymer film, a wider reflection bandwidth can be achieved. By utilizing compounds of formula RMT in polymerizable LC materials, the reflection bandwidth of the corresponding polymer film can be significantly broadened without adversely affecting film properties such as wet film crystallization or dewetting.

[0246] The concentration of the compound of formula RMT and its sub-formulae in the polymerisable LC material is preferably from 40% to 99%, more preferably from 45% to 95%, especially from 50% to 90%.

[0247] Compounds of formula RMT are commercially available from Merck KGaA, Darmsstadt or can be synthesized according to the procedures given, for example, in US 6,514,578 or US 15 / 575,415.

[0248] In a preferred embodiment, the polymerisable LC material comprises one or more di- or polyreactive reactive mesogens, preferably selected from the group consisting of DRMs of the formula

[0249] P 1 -Sp 1 -MG-Sp 2 -P 2 DRM

[0250] in

[0251] P 1 and P 2 represent, independently of one another, a polymerizable group,

[0252] Sp 1 and Sp 2 are independently a spacer group or a single bond, and

[0253] MG is a rod-shaped mesogenic group, which is preferably selected from the formula MG

[0254] -(A 1 -Z 1 ) n -A 2 -MG

[0255] Among them A 1 and A 2represents, independently of one another in the case of multiple occurrences, 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,

[0256] 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 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,

[0257] R x and R y independently of one another represent H or an alkyl group having 1 to 12 C atoms,

[0258] Z 1 In case of multiple occurrence, independently of one another, represents -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-, -(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,

[0259] Y 1 and Y 2 independently represent H, F, Cl or CN,

[0260] n is 1, 2, 3 or 4, preferably 1 or 2, most preferably 2,

[0261] n1 is an integer from 1 to 10, preferably 1, 2, 3 or 4,

[0262] However, there is a proviso that compounds of formula RMT are excluded from compounds of formula DRM.

[0263] Preferred group A 1 and A 2 Including, but not limited to, furan, pyrrole, thiophene, oxazole, thiazole, thiadiazole, imidazole, phenylene, cyclohexylene, dicyclooctylene, 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.

[0264] 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-tetrahydro-naphthalene-2,6-diyl, indan-2,5-diyl, bicyclooctylene or 1,4-cyclohexylene, in which one or two non-adjacent CH2 groups are optionally replaced by O and / or S, wherein these groups are unsubstituted or substituted by 1, 2, 3 or 4 groups L as described above.

[0265] Preferred RMs of formula DRM are selected from the group consisting of formula DRMa

[0266]

[0267] in

[0268] P 0 is, in the case of multiple occurrences, independently of one another, a polymerizable group, preferably an acryloyl, methacryloyl, oxetane, epoxy, vinyl, heptadiene, vinyloxy, propenyl ether or styrene group,

[0269] Z 0 It is -COO-, -OCO-, -CH2CH2-, -CF2O-, -OCF2-, -C≡C-, -CH=CH-,-

[0270] OCO-CH=CH-, -CH=CH-COO- or single bond,

[0271] L has, identically or differently on each occurrence, one of the meanings given for L in the formula DRM and is preferably selected independently of one another in the case of multiple occurrences from F, Cl, CN or optionally halogenated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 5 C atoms,

[0272] r is 0, 1, 2, 3, or 4,

[0273] x and y are independently 0 or the same or different integers from 1 to 12,

[0274] z is 0 or 1, and if the adjacent x or y is 0, then z is 0.

[0275] Very preferred RMs of formula DRM are selected from the following formulae:

[0276]

[0277]

[0278] Among them, P 0 , L, r, x, y and z are as defined in formula DRMa.

[0279] Particularly preferred are compounds of the formulae DRMa1, DRMa2 and DRMa3, in particular those of the formula DRMa1.

[0280] The concentration of di- or polyreactive RMs (preferably those of formula DRM and subformulae thereof) in the RM mixture is preferably from 1% to 60%, very preferably from 5% to 40%.

[0281] In another embodiment, the RM mixture comprises one or more monoreactive RMs. These additional monoreactive RMs are preferably selected from the group consisting of MRMs of the formula:

[0282] P 1 -Sp 1 -MG-R MRM

[0283] Among them, P 1 、Sp 1 and MG has the meaning given in Formula DRM,

[0284] 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,

[0285] X is a halogen, preferably F or Cl, and

[0286] R x and R y are independently of one another H or alkyl having 1 to 12 C atoms, with the proviso, however, that compounds of the formula RMT are excluded from compounds of the formula MRM.

[0287] Preferably the compound of formula MRM is selected from the following formula.

[0288]

[0289]

[0290]

[0291] Among them, P 0 , L, r, x, y and z are as defined in formula DRMa,

[0292] 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-(CH2) y -(O) z -,

[0293] X 0 Is -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 01 -、-NR 01 -CO-、-NR 01 -CO-NR 01 -, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 01 -, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or single bond

[0294] Y 0is F, Cl, CN, NO2, OCH3, OCN, SCN, SF5 or a monofluorinated, oligofluorinated or polyfluorinated alkyl or alkoxy group having 1 to 4 C atoms,

[0295] Z 0 is -COO-, -OCO-, -CH2CH2-, -CF2O-, -OCF2-, -CH=CH-, -OCO-CH=CH-, -CH=CH-COO- or a single bond,

[0296] 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,

[0297] R 01,02 H, R independently of each other 0 or Y 0 ,

[0298] u and v are independently 0, 1 or 2,

[0299] w is 0 or 1,

[0300] The benzene and naphthalene rings may be substituted by one or more identical or different groups L.

[0301] Especially preferred are compounds of the formula MRM1, MRM2, MRM3, MRM4, MRM5, MRM6, MRM7, in particular those of the formula MRM1, MRM4, MRM6 and MRM7.

[0302] The concentration of all monoreactive RMs (including those with formula RMT) in the polymerisable LC material is preferably from 1% to 80%, very preferably from 5% to 20%.

[0303] In the formulae DRM, MRM and preferred subformulae thereof, L is preferably selected from F, Cl, CN, NO2 or a linear or branched alkyl group, alkoxy group, alkylcarbonyl group, alkoxycarbonyl group, alkylcarbonyloxy group or alkoxycarbonyloxy group having 1 to 12 C atoms, wherein the alkyl group is optionally perfluorinated, or P-Sp-.

[0304] Very preferably, L is selected from F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, in particular F, Cl, CN, CH3, C2H5, C(CH3)3, CH(CH3)2, OCH3, COCH3 or OCF3, most preferably F, Cl, CH3, C(CH3)3, OCH3 or COCH3 or P-Sp-.

[0305] Preferably, the polymerizable LC material according to the present invention comprises one or more chiral compounds. These chiral compounds may be non-mesogenic or mesogenic. Furthermore, these chiral compounds, whether mesogenic or non-mesogenic, may be non-reactive, monoreactive or polyreactive.

[0306] Preferably, the chiral compounds used have a density of 20 μm each alone or in combination with one another. -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 Helical twisting forces (IHTP) in the range of 总 I) absolute value.

[0307] Preferably, the non-polymerizable chiral compound is selected from compounds of formulae CI to C-III,

[0308]

[0309] The latter includes the corresponding (S,S) enantiomers,

[0310] wherein E and F are each independently 1,4-phenylene or trans-1,4-cyclohexylene, v is 0 or 1, Z 0 is -COO-, -OCO-, -CH2CH2- or a single bond, and R is an alkyl group, an alkoxy group or an alkanoyl group having 1 to 12 C atoms.

[0311] Especially preferred polymerisable LC materials comprise one or more chiral compounds, which compounds do not necessarily have to exhibit a liquid crystal phase.

[0312] Compounds of formula C-II and their synthesis are described in WO 98 / 00428. Particularly preferred is compound CD-1 as shown in Table D below. Compounds of formula C-III and their synthesis are described in GB 2 328 207.

[0313] Commonly used chiral compounds include, for example, commercially available R / S-5011, CD-1, R / S-811, and CB-15 (from Merck KGaA, Darmsstadt, Germany).

[0314] The chiral compounds R / S-5011 and CD-1 mentioned above and (other) compounds of the formulae CI, C-II and C-III exhibit very high helical twisting powers (HTPs) and are therefore particularly useful for the purposes of the present invention.

[0315] The polymerisable LC material preferably comprises 1 to 5, in particular 1 to 3, very preferably 1 or 2 chiral compounds, preferably selected from formula C-II, in particular CD-1 and / or formula C-III and / or R-5011 or S-5011 above, very preferably the chiral compound is R-5011, S-5011 or CD-1.

[0316] Preferably, the polymerisable LC material comprises one or more non-reactive chiral compounds and / or one or more reactive chiral compounds, which compounds are preferably selected from mono-reactive and / or poly-reactive chiral compounds.

[0317] Suitable mesogenically reactive chiral compounds preferably comprise one or more ring elements, which are linked together by a direct bond or via a linking group, and wherein two of these ring elements are optionally linked to each other directly or via a linking group, which linking group may be the same as or different from the mentioned linking group. The ring elements are preferably selected from a 4-membered ring, a 5-membered ring, a 6-membered ring or a 7-membered ring, preferably a 5-membered ring or a 6-membered ring.

[0318] Preferred monoreactive chiral compounds are selected from compounds of formulae CRMa to CRMc.

[0319]

[0320]

[0321] in

[0322] P 0* Represents a polymerizable group P

[0323] Sp* represents a spacer group Sp

[0324] 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,

[0325] X 1 and X 2 are independently -O-, -COO-, -OCO-, -O-CO-O- or a single bond,

[0326] Z 0* In the case of multiple occurrences, it is independently of one another -COO-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -CF2O-, -OCF2-, -CH2CH2-, -(CH2)4-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -C≡C-, -CH=CH-, -CH=CH-COO-, -OCO-CH=CH- or a single bond,

[0327] t is independently 0, 1, 2 or 3,

[0328] a is 0, 1, or 2,

[0329] b is 0 or an integer from 1 to 12,

[0330] z is 0 or 1,

[0331] The naphthalene ring in the formula CRMa may be further substituted by one or more identical or different groups L

[0332] in

[0333] L is independently of one another F, Cl, CN, halogenated alkyl having 1 to 5 C atoms, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy.

[0334] The compound of formula CRMa is preferably selected from the compounds of formula CRMa-1.

[0335]

[0336] where X 2 , A 0 , B 0 , Z 0* , P 0* and b have the meanings given in formula CRMa or one of the preferred meanings given above and below, and (OCO) represents -O-CO- or a single bond.

[0337] Particularly preferred compounds of formula CRM are selected from the following sub-formula:

[0338]

[0339]

[0340] wherein R is -X as defined in formula CRM-a 2-(CH2) x -P 0* , and the benzene and naphthalene rings are unsubstituted or substituted with 1, 2, 3 or 4 groups L as defined above and below.

[0341] The compound of formula CRMb is preferably selected from the compounds of formulae CRMb-1 to CRMb-3,

[0342]

[0343] where X 2 , A 0 , B 0 , Z 0* , P 0* and b have the meanings given in formula CRMa or one of the preferred meanings given above and below.

[0344] Preferred compounds of formula CRMb-1 are preferably selected from compounds of formula CRMb-1a and CRMb-1b,

[0345]

[0346]

[0347] where X 2 , Z 0* , P 0* and b have the meanings given in formula CRMa or one of the preferred meanings given above and below. Preferably, in the compounds of formula CRMb-1a and CRMb-1b, Z 0 represents OCOO, COO, OCO or a single bond. Preferably, in the compounds of formula CRMb-1a and CRMb-1b, X 2 represents OCOO, OCO, COO or a single bond. Preferred are compounds of formula CRMb-1b selected from the following compounds,

[0348]

[0349] Among them, P 0* and b have the meanings given in formula CRMa or one of the preferred meanings given above and below.

[0350] Among them, P 0* The compound CRMb-1bI, in which a represents an acrylate group at each occurrence and b represents 4 at each occurrence, is particularly preferred and is commercially available under the trade name LC756 from BASF, Germany.

[0351] The compound of formula CRMc is preferably selected from the compounds of formula CRMc-1,

[0352]

[0353] where X 2 , A 0 , B 0 , Z 0* , P 0* and b have the meanings given in formula CRMa or one of the preferred meanings given above and below.

[0354] Preferred compounds of formula CRMc-1 are preferably selected from compounds of formula CRMc-1a and CRMc-1b,

[0355]

[0356] where X 2 , Z 0* , P 0* and b have the meanings given in formula CRMa or one of the preferred meanings given above and below. Preferably, in the compounds of formula CRMc-1a and CRMc-1b, Z 0 represents OCOO, COO, OCO or a single bond. Preferably, in the compounds of formula CRMc-1a and CRMc-1b, X 2 represents O, OCOO, OCO, COO or a single bond. Preferred compounds of formula CRMc-1a are selected from the following compounds:

[0357]

[0358] Among them, P 0* and b have the meanings given in formula CRMa or one of the preferred meanings given above and below.

[0359] Compound CRMc-1aI (where P 0* represents an acrylate group at each occurrence and b represents 3 or 6 at each occurrence, and X 2 represents O or a single bond at each occurrence) is especially preferred.

[0360] The amount of chiral compound in the liquid-crystalline medium is preferably 1 to 20%, more preferably 1 to 15%, even more preferably 1 to 10%, and most preferably 3 to 7%, based on the weight of the total mixture.

[0361] In a preferred embodiment, the proportion of the polymerizable mesogenic compound as a whole in the polymerizable liquid crystal material according to the present invention is in the range of 30 to 99 wt %, more preferably in the range of 40 to 97 wt %, even more preferably in the range of 50 to 95 wt %.

[0362] 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 polymerizable liquid crystal material according to the present invention) as a whole 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.

[0363] In a preferred embodiment, the proportion of the di- or polyreactive polymerizable mesogenic compound as a whole in the polymerizable liquid crystal material according to the present invention is preferably in the range of 1 to 70 wt %, more preferably in the range of 2 to 60 wt %, even more preferably in the range of 3 to 50 wt %.

[0364] In another preferred embodiment, the proportion of monoreactive polymerizable mesogenic compounds of formula MRM (which excludes compounds of formula RMT), if present, in the polymerizable liquid-crystalline material according to the invention as a whole is preferably in the range of 1 to 50 wt.-%, more preferably in the range of 2 to 45 wt.-%, even more preferably in the range of 5 to 40 wt.-%.

[0365] In another preferred embodiment, the proportion of the multireactive polymerizable mesogenic compound as a whole in the polymerizable liquid-crystalline material according to the present invention, if present, is preferably in the range of 1 to 30 wt.-%, more preferably in the range of 2 to 20 wt.-%, even more preferably in the range of 3 to 10 wt.-%.

[0366] In another preferred embodiment the polymerisable LC material does not comprise a polymerisable mesogenic compound having more than two polymerisable groups.

[0367] In another preferred embodiment, the polymerisable LC material comprises one or more monoreactive mesogenic compounds, preferably selected from formula MRM-1, MRM-4, MRM-6 and / or MRM-7, one or more direactive mesogenic compounds, preferably selected from formula DRMa-1.

[0368] Furthermore, the polymerizable LC material should also have the property that different reflection wavelengths, in particular in the VIS region, can be achieved by simple and targeted variation. Preferably, the cholesteric pitch of the polymerizable LC material is selected such that its reflection wavelength is within the infrared range of the electromagnetic spectrum, i.e., within the range of 300 nm to 900 nm, more preferably within the range of 350 to 850 nm. In particular, the reflection wavelength of the liquid crystal medium is within the range of 400 nm to 800 nm.

[0369] The polymerisable LC materials according to the present invention are prepared in a conventional manner per se, for example by mixing one or more of the above-mentioned polymerisable compounds with one or more block copolymers as described above and below and one or more chiral compounds (all as described above), and optionally with further liquid-crystalline compounds and / or additives and / or solvents.

[0370] In another preferred embodiment, the polymerizable LC material optionally comprises one or more additives selected from the group consisting of: additional polymerization initiators, antioxidants, surfactants, stabilizers, catalysts, sensitizers, inhibitors, chain transfer agents, co-reactive monomers, reactive viscosity reducers, surface-active compounds, lubricants, wetting agents, dispersants, hydrophobic agents, adhesives, flow improvers, degassing agents or defoaming agents, deaerators, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments and nanoparticles.

[0371] In a further preferred embodiment, the polymerisable LC material optionally comprises one or more additives selected from polymerisable non-mesogenic compounds (reactive viscosity reducing agents).The amount of these additives in the polymerisable LC material is preferably 0 to 30%, very preferably 0 to 25%.

[0372] The reactive viscosity reducers used are not only substances which are called reactive viscosity reducers in the true sense, but are also the 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 a reaction with the polymerizable units of the liquid-crystal compound can occur.

[0373] 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 lauric acid, myristic acid, palmitic acid and stearic acid, and vinyl esters of dicarboxylic acids, such as succinic acid and adipic acid, allyl and vinyl ethers of monofunctional alcohols, methacrylic acid and acrylates, such as lauryl alcohol, myristyl alcohol, palmityl alcohol and stearyl alcohol, and diallyl and divinyl ethers of difunctional alcohols, such as ethylene glycol and 1,4-butanediol.

[0374] 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.

[0375] Further suitable reactive viscosity reducers are polyester (meth)acrylates, which are (meth)acrylates of polyester polyols.

[0376] 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 their isomers and hydrogenation products, and esterifiable or transesterifiable 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 types.

[0377] In addition, suitable reactive viscosity reducing agents are 1,4-divinylbenzene, triallyl cyanurate, acrylic acid esters of tricyclodecenyl alcohol of the formula

[0378]

[0379] Also known as dihydrodicyclopentadienyl acrylate, and allyl esters of acrylic acid, methacrylic acid, and cyanoacrylic acid.

[0380] Among the reactive viscosity reducers mentioned by way of example, use is made in particular and in view of the preferred compositions mentioned above, of those comprising photopolymerizable groups.

[0381] This group includes, for example, diols and polyols, such as ethylene glycol, propylene glycol and their more highly condensed representatives, for example diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, etc., 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.

[0382] Furthermore, the group includes, for example, alkoxylated phenolic compounds, such as ethoxylated and propoxylated bisphenols.

[0383] Furthermore, these reactive viscosity reducing agents may be, for example, epoxy or urethane (meth)acrylates.

[0384] Epoxy (meth)acrylates are, for example, those obtainable by reacting epoxidized olefins or poly- or diglycidyl ethers, such as bisphenol A diglycidyl ether, with (meth)acrylic acid, as is known to those skilled in the art.

[0385] 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.

[0386] Such epoxy and urethane (meth)acrylates are included as "mixed forms" in the compounds listed above.

[0387] If reactive viscosity-reducing agents are used, their amount and properties must be adapted to the respective conditions so that, on the one hand, the desired effect, for example the desired color of the composition according to the invention, is achieved satisfactorily, 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.

[0388] For example, the group of diluents includes:

[0389] 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 tripropylene glycol, ethers, for example methyl tert-butyl ether, 1,2-ethanediol mono- and dimethyl ether, 1 , 2-ethylene glycol mono- and diethyl 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.

[0390] It is of course also possible to use mixtures of these diluents in the compositions according to the invention.

[0391] These diluents can also be mixed with water, provided there is at least partial miscibility. Examples of suitable diluents 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.

[0392] 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 material.

[0393] Defoamers and deaerators (c1)), lubricants and flow control agents (c2)), thermal or radiation curing agents (c3)), substrate wetting agents (c4)), wetting and dispersing agents (c5)), hydrophobic agents (c6)), adhesion promoters (c7)) and agents promoting scratch resistance (c8)) cannot be strictly separated from one another by their action.

[0394] 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 serve as lubricants and flow aids and / or degassing agents and / or substrate wetting aids. In various cases, some of these additives can also perform the function of adhesion promoters (c8).

[0395] Corresponding to what has been said above, certain additives can therefore be classified into several groups c1) to c8) described below.

[0396] 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 derivable from ethylene oxide or propylene oxide.

[0397] 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.

[0398] The action of defoamers is essentially based on preventing foam formation or disrupting already formed foam. In a medium to be degassed, such as the composition according to the invention, defoamers essentially act by promoting the merging of finely divided gas or air bubbles to form larger bubbles, thereby accelerating the escape of gas (or air). Since defoamers can often also act as deaerators and vice versa, these additives are also included in group c1).

[0399] For example, such additives are available from Tego Foamex 800, Foamex 805, Foamex 810, Foamex 815, Foamex 825, Foamex835, Foamex 840, Foamex 842, Foamex 1435, Foamex 1488, Foamex 1495, Foamex 3062, Foamex 7447, Foamex 8020, Foamex N, Foamex K 3, Antifoam2-18, Antifoam 2-18, Antifoam 2-57, Antifoam2-80, Antifoam 2-82, Antifoam 2-89, Antifoam2-92, Antifoam 14, Antifoam 28, Antifoam81, Antifoam D 90, Antifoam 93, Antifoam200, Antifoam 201, Antifoam 202, Antifoam793, Antifoam1488、 Antifoam 3062、 5803、 5852、 5863、 7008、 Antifoam 1-60、 Antifoam 1-62、 Antifoam 1-85 Antifoam 2-67、 Antifoam WM 20、 Antifoam50、 Antifoam 105、 Antifoam730、 Antifoam MR 1015、 Antifoam MR 1016、 Antifoam1435、 Antifoam N、 Antifoam KS 6、 Antifoam KS10、 Antifoam KS 53、 Antifoam KS 95、 Antifoam KS100、 Antifoam KE 600、 Antifoam KS 911、 Antifoam MR 1000、 Antifoam KS1100、 Airex 900、 Airex910、 Airex 931、 Airex 935、 Airex 936、 Airex960、 Airex 970、 Airex 980 and Airex 985 are commercially available and obtained from BYK at

[0400]

[0401] and Commercially available.

[0402] The auxiliaries in group c1) are optionally used in a proportion of about 0 to 3.0 wt. %, preferably about 0 to 2.0 wt. %, based on the total weight of the polymerisable LC material.

[0403] In group c2), lubricants and flow aids generally include silicon-free and silicon-containing polymers, such as polyacrylates or, as 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 (fluorinated) alkyl groups, the former being the most commonly used.

[0404] The polyether groups in the correspondingly modified polysiloxanes are generally 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.

[0405] For example, such additives are available from Tego Glide 100, Glide ZG 400, Glide 406, Glide 410, Glide 411, Glide415, Glide 420, Glide 435, Glide440, Glide450, 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 ZFS 460 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.

[0406] Such additives are also available from BYK, for example. 354, get.

[0407] Such adjuvants are also available from 3M, for example.

[0408] Such adjuvants are also available commercially, for example, from Cytonix, such as or

[0409] Such auxiliaries are also commercially available, for example, from Merck KGaA, such as 2300 and 2500.

[0410] The auxiliaries in group c2) are optionally used in an amount of about 0 to 3.0 wt.-%, preferably about 0 to 2.0 wt.-%, based on the total weight of the polymerisable LC material.

[0411] In group c3), radiation-curing auxiliaries include, in particular, polysiloxanes having terminal double bonds, for example, components in which the terminal double bonds are acrylate groups. Such auxiliaries can be crosslinked actinically or, for example, by electron radiation. These auxiliaries generally combine several properties. In the uncrosslinked state, they can act as defoamers, deaerators, lubricants, 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 produced using the compositions according to the invention. Improvements in gloss properties, such as those of coatings or films, are primarily believed to be a result of the action of these auxiliaries as defoamers, deaerators, and / or lubricants and flow aids (in the uncrosslinked state).

[0412] Examples of suitable radiation curing auxiliaries are the products available from TEGO Rad2100, Rad 2200, Rad 2500, Rad 2600 and Rad 2700 and products available from BYK

[0413] The thermal curing auxiliaries in group c3) contain, for example, primary OH groups which are capable of reacting, for example, with isocyanate groups of the adhesive.

[0414] Examples of useful thermal curing aids are the products available from BYK and

[0415] The auxiliaries in group c3) are optionally used in a proportion of about 0 to 5.0 wt.-%, preferably about 0 to 3.0 wt.-%, based on the total weight of the polymerisable LC material.

[0416] The substrate wetting additives 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 generally accompanying improvement in the lubrication and flow behavior of such printing inks or coating compositions has an impact on the appearance of the resulting (for example, crosslinked) prints or coatings.

[0417] A wide variety of such additives are available, for example, from Tego Wet KL 245, Wet250, Wet 260 and Wet ZFS 453 and from BYK and Commercially available.

[0418] 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.

[0419] 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.

[0420] These additives stabilize the pigment dispersions essentially 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 significant role.

[0421] 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.

[0422] Such wetting and dispersing aids are available, for example, from Tego Dispers 610, Dispers 610S, Dispers 630, Dispers 700, Dispers705, Dispers 710, Dispers 720W, Dispers 725W, Dispers 730W, Dispers 735W and Dispers 740W and from BYK 80. 104S, 105. and Commercially available.

[0423] The amount of the auxiliaries in group c5) is based on the average molecular weight of the auxiliaries. Therefore, preliminary experiments are advisable in any case, but this can be easily carried out by a person skilled in the art.

[0424] The hydrophobizing agents in group c6) can be used to impart hydrophobic properties to printed products or coatings produced, for example, using the compositions according to the invention. This prevents or at least significantly suppresses swelling due to water absorption and, therefore, changes in the optical properties of such printed products or coatings. Furthermore, when the compositions are used as printing inks, for example in offset printing, water absorption can be prevented or at least significantly reduced.

[0425] Such hydrophobic agents are available, for example, from Tego Phobe WF, Phobe 1000, Phobe 1000S, Phobe 1010, Phobe 1030, Phobe1010, Phobe 1010, Phobe 1030, Phobe 1040, Phobe 1050, Phobe 1200, Phobe 1300, Phobe 1310 and Phobe 1400 is commercially available.

[0426] The auxiliaries in group c6) are optionally used in a proportion of about 0 to 5.0 wt. %, preferably about 0 to 3.0 wt. %, based on the total weight of the polymerisable LC material.

[0427] The further adhesion promoters from group c7) serve to improve the adhesion of the two interfaces in contact. It is immediately apparent from this that essentially the only part of the adhesion promoter that is effective 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 varnish 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 known as priming), i.e., the substrate must be given modified chemical and / or physical surface properties.

[0428] If the substrate has been pre-primed with a primer, 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. 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.

[0429] 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.

[0430] 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 with which they are intended to be printed or coated, for example.

[0431] 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-methacryloyloxypropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane and vinyltrimethoxysilane. These and other silanes are available from Hüls, for example, under the trade name Commercially available.

[0432] Generally, the corresponding technical information from the manufacturers of such additives should be used, or the person skilled in the art can easily determine this information by corresponding preliminary experiments.

[0433] If, however, these additives are to be added as auxiliaries from group c7) to the polymerizable LC material according to the invention, their proportions are optionally from about 0 to 5.0% by weight, based on the total weight of the polymerizable LC material. These concentration figures serve only as a guide, since the amount and identity of the additives are determined in each individual case by the properties of the substrate and the printing / coating composition. In this case, 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 through appropriate preliminary experiments.

[0434] The auxiliaries in group c8) for improving the scratch resistance include, for example, the above-mentioned products available from Tego Rad 2100, Rad 2200, Rad 2500, Rad 2600 and Rad 2700.

[0435] 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.

[0436] Examples of other light, heat and / or oxidation stabilizers which may be mentioned are the following substances:

[0437] 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-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenol with linear or branched side chains, e.g. Such as 2,6-dinonyl-4-methylphenol, 2,4-dimethyl-6-(1′-methylundec-1′-yl)phenol, 2,4-dimethyl-6-(1′-methylheptadecan-1′-yl)phenol, 2,4-dimethyl-6-(1′-methyltridec-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-didodecylthiomethyl-4-nonylphenol,

[0438] 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,

[0439] Tocopherols, such as α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures of these compounds, and tocopherol derivatives, such as tocopherol acetate, succinate, nicotinate and polyoxyethylene succinate ("tocofersolate"),

[0440] 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,

[0441] Alkylenebisphenols, such as 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-tris(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(1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane) [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,

[0442] O-, N- and S-benzyl compounds, such as 3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tridecyl-4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate, 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-hydroxybenzylmercaptoacetate,

[0443] 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,

[0444] 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,

[0445] 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,

[0446] Acylaminophenols, such as 4-hydroxylauroylanilide, 4-hydroxystearylanilide, and octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate,

[0447] 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,

[0448] 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,

[0449] 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,

[0450] 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-allyldiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octyl-substituted diphenylamines such as p,p′-di-tert-octyldiphenylamine, 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-octyldiphenylamines, mixtures of mono- and di-alkylated nonyldiphenylamines, mixtures of mono- and di-alkylated dodecyldiphenylamines, mixtures of mono- and di-alkylated isopropyl / isohexyldiphenylamines mixtures, 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-octylphenothiazines, mixtures of mono- and di-alkylated tert-octylphenothiazines, N-allylphenothiazine, 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,

[0451] 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 -tris(tert-butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)4,4′-diphenylene diphosphonite, 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,

[0452] 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 with polyethylene glycol 300;

[0453] Sulfur-containing peroxide scavengers and sulfur-containing antioxidants, such as esters of 3,3′-thiodipropionic acid, for example lauryl, stearyl, myristyl and tridecyl esters, mercaptobenzimidazole and zinc salts of 2-mercaptobenzimidazole, dibutylzinc dithiocarbamate, dioctadecyl disulfide and pentaerythritol tetrakis(β-dodecylmercapto)propionate,

[0454] 2-Hydroxybenzophenones, such as 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2′,4′-trihydroxy and 2′-hydroxy-4,4′-dimethoxy derivatives,

[0455] 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,

[0456] 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-ethylenediamine) )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-tetramethylpiperidine, condensation products of N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, condensation products of 1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine, 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,

[0457] Oxamides, such as 4,4′-dioctyloxyoxalanilide, 2,2′-diethoxyoxalanilide, 2,2′-dioctyloxy-5,5′-di-tert-butoxanilide, 2,2′-didodecyloxy-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

[0458] 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.

[0459] In another preferred embodiment, the polymerisable LC material comprises preferably selected from One or more specific antioxidant additives from the VITAMIN® series, such as the antioxidants available from Ciba, Switzerland. 1076 and 1010.

[0460] In another preferred embodiment, the polymerizable LC material comprises one or more, more preferably a combination of two or more photoinitiators, for example selected from 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, additionally selected from the commercially available OXE02 (Ciba AG), NCI 930, N1919T (Adeka), SPI-03 or SPI-04 (Samyang).

[0461] The concentration of the polymerisation initiator in the polymerisable LC material as a whole is preferably 0.5-10%, very preferably 0.8-8%, more preferably 1-6%.

[0462] In a preferred embodiment, the polymerisable LC material is dissolved in a suitable solvent, which is preferably selected from organic solvents.

[0463] 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, 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) and gamma-butyrolactone. Binary, ternary, or higher-order mixtures of the above solvents may also be used. In particular, methyl isobutyl ketone is a preferred solvent for multi-layer application.

[0464] In case the polymerisable LC material comprises one or more solvents, the total concentration of all solids (including RMs) in the solvent is preferably from 10% to 60%, more preferably from 20% to 50%, especially from 30% to 45%.

[0465] Preferably, the polymerisable LC material comprises, in addition to one or more block copolymers

[0466] a) one or more polymerizable mesogenic compounds of the formula RMT and corresponding subformulae,

[0467] b) optionally one or more poly- or di-reactive polymerizable mesogenic compounds, preferably selected from the group consisting of compounds of formula DRM and corresponding sub-formulae,

[0468] c) one or more chiral mesogenic compounds, preferably selected from the group consisting of compounds of formulae CRMa to CRMc (more preferably CRMb) and subformulae thereof,

[0469] d) optionally one or more monoreactive mesogens, preferably selected from compounds of formula MRM and corresponding subformulae,

[0470] e) optionally one or more photoinitiators,

[0471] f) optionally one or more antioxidant additives,

[0472] g) optionally one or more adhesion promoters,

[0473] h) optionally one or more surfactants,

[0474] i) optionally one or more monoreactive, direactive or polyreactive polymerizable non-mesogenic compounds,

[0475] j) optionally one or more dyes showing an absorption maximum at the wavelength used to initiate photopolymerization,

[0476] k) optionally one or more chain transfer agents,

[0477] l) optionally one or more other stabilizers,

[0478] m) optionally one or more lubricants and flow aids, and

[0479] n) optionally one or more diluents,

[0480] o) optionally a non-polymerizable nematic component,

[0481] p) optionally one or more organic solvents.

[0482] More preferably, the polymerisable LC material comprises:

[0483] a) one or more block copolymers as given above or their corresponding preferred formulas,

[0484] b) one or more, preferably two or more, polymerizable mesogenic compounds of formula RMT and corresponding subformulae, preferably selected from compounds of subformulae RMTa2-A4 and / or RMTa2-A5 and / or RMTb-A3,

[0485] c) one or more, preferably two or more, direactive polymerizable mesogenic compounds, preferably selected from compounds of formula DRMa-1,

[0486] d) optionally one or more, preferably two or more, monoreactive polymerizable mesogenic compounds, preferably selected from compounds of formula MRM-1 and / or MRM-4 and / or MRM-6 and / or MRM-7,

[0487] e) optionally one or more chiral mesogenic compounds of formula CRMb, in particular of formula CRMb-1bI,

[0488] f) optionally one or more antioxidant additives, preferably selected from esters of unsubstituted and substituted benzoic acids, in particular 1076, and if present, preferably 0.01-2 wt. %, very preferably 0.05-1 wt. %,

[0489] g) optionally one or more photoinitiators, preferably 907 and / or SPI-3,

[0490] h) optionally one or more organic solvents, preferably methyl isobutyl ketone.

[0491] The present invention further relates to a method for preparing a polymer film by

[0492] - providing a layer of polymerisable LC material as described above and below onto a substrate,

[0493] - polymerising the polymerisable component of the polymerisable LC material by photopolymerisation, and

[0494] - optionally removing the polymerized LC material from the substrate, and / or optionally providing the polymerized LC material onto another substrate.

[0495] The polymerizable LC material may be coated or printed onto a substrate, for example by spin coating, printing or other known techniques, and the solvent evaporated off before polymerisation.In most cases it will be appropriate to heat the mixture to promote evaporation of the solvent.

[0496] The polymerisable LC material can be applied to the substrate by conventional coating techniques such as spin coating, rod coating or knife coating. The polymerisable LC material 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, intaglio printing, pad printing, heat seal printing, inkjet printing or printing with the aid of a stamp or printing plate.

[0497] Suitable substrate materials 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 plastic. 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), or cycloolefin polymers (COP), or known color filter materials, in particular triacetyl cellulose (TAC), cycloolefin polymers (COP) or known color filter materials.

[0498] The polymerisable LC material preferably shows a uniform alignment throughout the layer.Preferably the polymerisable LC material shows a uniform planar, uniform homeotropic, uniform cholesteric or patterned alignment.

[0499] The Friedel-Creagh-Kmetz rule is performed by comparing the RM layers (γ RM ) and substrate (γ s ) can be used to predict whether the mixture will adopt a planar or homeotropic alignment:

[0500] If γ RM >γ s , then the reactive mesogenic compound will show homeotropic alignment, if γ RM <γ s , then the reactive mesogen compound will show planar alignment.

[0501] Without being bound by theory, when the surface energy of the substrate is relatively low, the intermolecular forces between reactive mesogens are stronger than the forces across the RM-substrate interface, and therefore, the reactive mesogens align perpendicular to the substrate (homeotropic alignment) to maximize the intermolecular forces.

[0502] Homeotropic alignment can also be achieved by using amphiphilic materials; these can be added directly to the polymerizable LC material, or the substrate can be treated with these materials in the form of a homeotropic alignment layer. The polar head of the amphiphilic material chemically bonds to the substrate, while the hydrocarbon tail points perpendicularly to the substrate. Intermolecular interactions between the amphiphilic material and the RM promote homeotropic alignment. Commonly used amphiphilic surfactants are described above.

[0503] Another method for promoting homeotropic alignment is to apply corona discharge treatment to the plastic substrate, thereby generating alcohol or ketone functional groups on the substrate surface. These polar groups can interact with the polar groups present in RMs or surfactants to promote homeotropic alignment.

[0504] When the surface tension of the substrate is greater than that of the RM, the forces across the interface dominate. If the reactive mesogens are aligned parallel to the substrate, allowing the long axis of the RM to interact with the substrate, the interfacial energy is minimized. Unidirectional planar alignment can be promoted by coating the substrate with a polyimide layer and then rubbing the alignment layer with a velvet cloth.

[0505] Other suitable planar alignment layers are known in the art, such as for example rubbed polyimides or alignment layers prepared by photoalignment, as described in US 5,602,661, US 5,389,698 or US 6,717,644.

[0506] In general, an overview of alignment techniques is given by I. Sage in "Thermotropic Liquid Crystals", edited by G.W. Ray, John Wiley & Sons, 1987, pp. 75-77; and by T. Uchida and H. Seki in "Liquid Crystals - Applications and Uses Volume 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.

[0507] To prepare the polymer film according to the present invention, the polymerisable compounds in the polymerisable LC material are polymerised or crosslinked (if one compound contains two or more polymerisable groups) by in situ photopolymerisation.

[0508] The photopolymerization can be carried out in one step. It is also possible to photopolymerize or crosslink the compounds that did not react in the first step in a second step ("finish curing").

[0509] In a preferred method of preparation, a polymerisable LC material is coated on a substrate and then photopolymerised by exposure to actinic radiation as described, for example, in WO 01 / 20394, GB 2,315,072 or WO 98 / 04651.

[0510] Photopolymerization of the LC material is preferably achieved by exposing it to actinic radiation. Actinic radiation is understood to mean 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, polymerization is carried out by irradiation, in particular with UV light. 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 reduced. Another feasible source for optical radiation is a laser, such as, for example, a UV laser, an IR laser or a visible laser. Another possible source for optical radiation is an LED lamp.

[0511] The curing time depends, inter alia, on the reactivity of the polymerizable LC material, 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, and most preferably ≤1 minute. For mass production, a short curing time of ≤30 seconds is preferred.

[0512] Suitable UV radiation power is preferably in the range of 5 to 200 mWcm -2in the range of 50 to 175 mWcm -2 in the range and most preferably in the range of 100 to 150 mWcm -2 within the range.

[0513] Suitable UV doses are preferably in the range of 25 to 7200 mJ cm-2, depending on the UV radiation applied and as a function of time. -2 in the range of 100 to 7200 mJcm -2 and most preferably in the range of 200 to 7200 mJcm -2 within the range.

[0514] The photopolymerization is preferably carried out in an inert gas atmosphere, preferably a heated nitrogen atmosphere, but polymerization in air is also possible.

[0515] The photopolymerization is preferably carried out at a temperature of 1 to 70°C, preferably 5 to 50°C, even more preferably 15 to 30°C.

[0516] The polymerized LC film according to the present invention has good adhesion to plastic substrates, in particular to TAC, COP and color filters. Therefore, it can be used as an adhesive or base coating for subsequent LC layers that would otherwise not adhere well to the substrate.

[0517] 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.

[0518] The optical retardation (δ(λ)) of the polymer film as a function of the wavelength (λ) of the incident light beam is given by the following equation (7):

[0519] δ(λ)=(2πΔn·d) / λ (7)

[0520] where (Δn) is the birefringence of the film, (d) is the thickness of the film and λ is the wavelength of the incident light beam.

[0521] According to Snellius's law, the birefringence as a function of the direction of the incident light beam is defined as

[0522] Δn = sinΘ / sinΨ (8)

[0523] where sinΘ is the angle of incidence or the tilt angle of the optical axis in the film, and sinΨ is the corresponding reflection angle.

[0524] Based on these laws, the birefringence and therefore the optical retardation depends on the thickness of the film and the tilt angle of the optical axis in the film (see Berek compensator). Therefore, the skilled person realized that different optical retardations or different birefringence can be induced by adjusting the orientation of the liquid crystal molecules in the polymer film.

[0525] The birefringence (Δn) of the polymer film according to the present invention is preferably in the range of 0.01 to 0.4, more preferably in the range of 0.01 to 0.3 and even more preferably in the range of 0.01 to 0.25.

[0526] The optical retardation as a function of the thickness of the polymer film according to the invention is less than 200 nm, preferably less than 180 nm and even more preferably less than 150 nm.

[0527] The polymer films of the present invention can also be used as alignment films or substrates for other liquid crystal or LC materials. The inventors have found that polymer films obtainable from polymerizable LC materials as described above and below are particularly suitable for multilayer applications due to their improved dewetting properties. In this way, stacks of optical films or preferably polymerized LC films can be produced.

[0528] In summary, the polymerized LC films and polymerizable LC materials according to the invention can be used in optical elements such as polarizers, compensators, alignment layers, circular polarizers or color filters (in liquid crystal displays or projection systems), in decorative images, for the production of liquid crystals or effect pigments, and in particular in reflective films with spatially varying reflection colors, for example for decorative multicolor images, for information storage or security purposes, such as in unforgeable documents such as identity cards or credit cards, banknotes, etc.

[0529] The polymerized LC films according to the invention can be used in displays of the transmissive or reflective type. They can be used in conventional OLED displays or LCDs, in particular LCDs.

[0530] The invention has been described above and below with particular reference to preferred embodiments thereof. It will be understood that various changes and modifications can be made therein without departing from the spirit and scope of the invention.

[0531] Many of the compounds mentioned above and below or their mixtures are commercially available. All of 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), specifically under reaction conditions known and suitable for the reactions described. Variants known per se and not mentioned here can also be used.

[0532] It should be understood that the foregoing embodiments of the present invention may be modified while still falling within the scope of the present invention. Unless otherwise specified, alternative features serving 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 generic concept of equivalent or similar features.

[0533] 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. Similarly, features described in optional combinations may be used separately (not in combination).

[0534] It should be understood that many of the features described above, particularly the features of the preferred embodiments, are inventive in themselves and not merely as part of an embodiment of the invention. Independent protection may be sought for these features in addition to or in lieu of any invention currently claimed.

[0535] 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 invention.

[0536] Example

[0537] Example 1

[0538] The following formulations were prepared according to the given table: Formulation 1

[0539]

[0540] Formulation 2

[0541]

[0542]

[0543] Formulation 3

[0544]

[0545] Formulation 4

[0546]

[0547] Irganox 1076, LC756, and LC242 are commercially available from BASF, Germany, and SPI-3 is commercially available from Samyang Corporation, Korea.

[0548] Formulations 1 to 4 were dissolved to 20% solids in MIBK (methyl isobutyl ketone): 3-pentanone (8:2). Each host formulation was then doped with various surfactants to produce the final formulations shown in the table below.

[0549] Surfactant-doped formulations per host

[0550]

[0551]

[0552] Tego Airex 901, Tego Airex 920, Tego Airex 931, Tego Airex962, Tego Glide435, Tego Wet 260, Tego Wet 500, Tego Wet510, Tego Twin 4000 were commercially purchased from EvonikTego, Germany. Polyfox PF-3320 Polyfox PF-7002 Polyfox PF-656 are commercially available from Omnova Solutions Inc., USA.

[0553] Formulations 5-52 were spin-coated onto polyimide-rubbed glass at 1000 rpm for 30 s. The wet films were annealed at 60° C. for 60 s and irradiated under a Light Hammer 6 Fusion conveyor belt UV lamp (250 mJ cm -2 ). After the initial cure, each resulting film was visually inspected for CLC alignment and visible haze. An additional coating of the same formulation was applied on top in the same manner as described above. After the second annealing step, each multilayer coating was visually inspected for dewetting.

[0554] Comparative Formulations:

[0555]

[0556]

[0557]

[0558] The formulation according to the invention:

[0559]

[0560] O = Good (good alignment or no dewetting)

[0561] Δ = bad (acceptable CLC alignment / haze or some dewetting)

[0562] X = (extreme dewetting)

[0563] As can be seen in the table above, using Polyfox PF-656 (Formulations 15, 27, 39, and 51) as a surfactant provides an extremely wide range of concentrations that can be used to achieve CLC alignment. This surfactant selection also has a wide range of concentrations in which it does not cause dewetting of subsequent coating layers and also provides alignment with the overlying layer, thus eliminating the need for additional alignment layers between CLC layers. Similar results can be achieved with PolyFox PF 7002 (Formulations 14, 26, 38, and 50).

[0564] Example 2

[0565] The following formulations were prepared according to the given table:

[0566] Formulation 53

[0567]

[0568] Formulation 54

[0569]

[0570] Formulation 55

[0571]

[0572] Formulation 56

[0573]

[0574]

[0575]

[0576] Each formulation was dissolved in MIBK:3-pentanone (8:2) to 20% solids.

[0577] Formulations 53-57 were each coated onto a 5x rubbed cycloolefin polymer substrate using a Mayer rod 9. The wet films were annealed at 60°C for 60 s and irradiated under N2 with a Light Hammer 6 Fusion conveyor belt UV lamp (250 mJ cm -2 ). After curing, each film was visually inspected for CLC alignment. No film crystallization or dewetting was observed for any of the coated films. Each film was measured using a Shimadzu 3600 UV-Vis spectrometer to determine the reflection wavelength and reflection bandwidth. Film thickness was measured using a Dektak profilometer. The results of these measurements are shown in the table below.

[0578] Central wavelength, in nm Reflection bandwidth, in nm Film thickness, in μm Membrane 1 467 72 5.14 Membrane 2 504 76 5.75 Membrane 3 550 85 4.77 Membrane 4 610 96 5.38 Membrane 5 681 115 5.13

[0579] Example 3

[0580] The following formulations were prepared according to the given table:

[0581]

[0582]

[0583] The formulation was dissolved in MIBK:3-pentanone (8:2) to 40% solids.

[0584] Formulations 58 and 59 were spin-coated on polyimide-rubbed glass at 1000 rpm for 30 s. The wet films were annealed at 60° C. for 60 s and irradiated under a Light Hammer 6 Fusion conveyor belt UV lamp (250 mJ cm -2 ) is cured.

[0585] Each film was visually inspected for CLC alignment and visible haze after initial curing.

[0586] Film 6 obtained from formulation 58 showed excellent alignment and exhibited a main reflection bandwidth from 425 to 510.

[0587] Film 7 obtained from formulation 59 showed excellent alignment and exhibited a main reflection bandwidth from 550 to 675 nm.

[0588] Film 8 was obtained from a multilayer coating of formulation 59, applied and cured as described above, followed by application and curing of formulation 58 as described above on top of the polymer film obtained from formulation 59. The multilayer film exhibited one reflection bandwidth from 425 to 510 nm and a second main reflection bandwidth from 550 to 675 nm.

[0589] It can be seen that using the Polyfox PF656 surfactant, it is possible to coat one CLC film directly on top of another with a broad bandwidth for each layer. There is no adverse effect on the reflective properties of each layer, as can be seen by the overlapping reflection bands.

Claims

1. A polymerisable LC material comprising one or more reactive mesogenic compounds, one or more chiral compounds and a block copolymer comprising at least one polyfluorooxetane block in combination with a polyether block, wherein the polyfluorooxetane block has one or more repeating units of the formula Each of these n and m are each and independently an integer from 1 to 6, R is hydrogen or an alkyl group having 1 to 6 carbon atoms, R f and R f* Each and independently a linear or branched alkyl group of 1 to 20 carbon atoms, wherein the R f or R f* at least 50% of the hydrogen atoms of the alkyl group are replaced by F, and optionally up to all remaining H atoms are replaced by I, Cl or Br, DP is 2 to 100.

2. A polymerisable LC material according to claim 1, wherein the concentration of the block copolymer is from 0.01% to 1%.

3. A polymerisable LC material according to claim 1 or 2, comprising one or more reactive mesogens selected from the group consisting of formula RMT, in P is a polymerizable group, Sp is a spacer group or a single bond, r2 and r3 are independently 0, 1, 2, 3 or 4, R 11 is P-Sp-, alkyl, alkoxy, thioalkyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, A and B, in the case of multiple occurrences, independently of one another, represent an aromatic or alicyclic radical, which optionally contains one or more heteroatoms selected from N, O and S and which 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, or a straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 12 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 group having 1 to 12 C atoms, Z 11 and Z 12 In the case of multiple occurrences, independently of one another, represent -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O-COO-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH2CH2-, -(CH2) n1 , -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CY 1 =CY 2 -, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or single bond, Y 1 and Y 2 independently represent H, F, Cl or CN, n is 1, 2, 3 or 4, m is 0, 1, 2, 3 or 4, n1 is an integer from 1 to 10.

4. A polymerisable LC material according to claim 3, wherein R 11 is P-Sp-, alkyl, alkoxy, thioalkyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 15 C atoms.

5. A polymerisable LC material according to claim 3, wherein R 11 is P-Sp-, alkyl, alkoxy, thioalkyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, which is optionally fluorinated.

6. A polymerisable LC material according to claim 3 , wherein A and B, in the case of multiple occurrences, independently of one another, represent 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 CH2 groups are optionally replaced by O and / or S, wherein these groups are unsubstituted or substituted by 1, 2, 3 or 4 groups L.

7. A polymerisable LC material according to claim 3, wherein L is F, -CN or a linear or branched alkyl group, alkoxy group, alkylcarbonyl group, alkoxycarbonyl group, alkylcarbonyloxy group or alkoxycarbonyloxy group having 1 to 6 C atoms.

8. A polymerisable LC material according to claim 3, wherein Z 11 and Z 12 Multiple occurrences independently represent -COO-, -OCO-, -C≡C-, or a single bond.

9. A polymerisable LC material according to claim 3, wherein n is 1 or 2.

10. A polymerisable LC material according to claim 3, wherein n is 1.

11. A polymerisable LC material according to claim 3, wherein m is 0 or 1.

12. A polymerisable LC material according to claim 3, wherein m is 0.

13. A polymerisable LC material according to claim 3, wherein n1 is 1, 2, 3 or 4.

14. Polymerisable LC material according to claim 1 or 2, wherein the concentration of the compound of formula RMT is from 40% to 99%.

15. A polymerisable LC material according to claim 1 or 2, comprising one or more compounds selected from the group consisting of: P 1 -Sp 1 -MG-Sp 2 -P 2 DRM in P 1 and P 2 represent, independently of one another, a polymerizable group, Sp 1 and Sp 2 are independently of one another a spacer group or a single bond, and MG is a rod-shaped mesogenic group. However, there is a proviso that compounds of formula RMT are excluded from compounds of formula DRM.

16. A polymerisable LC material according to claim 15, wherein MG is selected from the formula MG -(A 1 -Z 1 ) n -A 2 -MG in A 1 and A 2 represents, in the case of multiple occurrences, independently of one another, an aromatic or alicyclic 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 C atoms, and straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 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 group having 1 to 12 C atoms, Z 1 In the case of multiple occurrences, -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O-COO-, -CO-NR are independently of one another. 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-, -(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 single bond, Y 1 and Y 2 independently represent H, F, Cl or CN, n is 1, 2, 3 or 4, n1 is an integer from 1 to 10.

17. A polymerisable LC material according to claim 16, wherein L is an aryl or heteroaryl group having 1 to 6 C atoms, or a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 6 C atoms, wherein one or more H atoms are optionally replaced by F or Cl.

18. A polymerisable LC material according to claim 16, wherein n1 is 1, 2, 3 or 4.

19. A polymerisable LC material according to claim 1 or 2, wherein the concentration of the compound of formula DRM is from 1% to 60%.

20. A polymerisable LC material according to claim 1 or 2, comprising one or more compounds selected from the group consisting of formula MRM: P 1 -Sp 1 -MG-R MRM in P 1 , Sp 1 and MG has the meaning given 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, linear or branched alkyl having 1 to 12 C atoms, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, wherein one or more H atoms are optionally replaced by F or Cl, X is a halogen, and R x and R y are independently H or alkyl having 1 to 12 C atoms, However, there is a proviso that compounds of formula RMT are excluded from compounds of formula MRM.

21. A polymerisable LC material according to claim 20, wherein R represents a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 6 C atoms, wherein one or more H atoms are optionally replaced by F or Cl.

22. A polymerisable LC material according to claim 20, wherein X is F or Cl.

23. A polymerisable LC material according to claim 1 or 2, comprising one or more reactive chiral compounds selected from compounds of formulae CRMa to CRMc, in P 0* Represents a polymerizable group P Sp* represents a spacer group Sp 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, X 1 and X 2 are independently -O-, -COO-, -OCO-, -O-CO-O- or a single bond, Z 0* in the case of multiple occurrences, independently of one another, is -COO-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -CF2O-, -OCF2-, -CH2CH2-, -(CH2)4-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -C≡C-, -CH=CH-, -CH=CH-COO-, -OCO-CH=CH- or a single bond, t is independently 0, 1, 2 or 3, a is 0, 1 or 2, b is 0 or an integer from 1 to 12, z is 0 or 1, The naphthalene ring in the formula CRMa may be further substituted by one or more identical or different groups L in L is independently of one another F, Cl, CN, halogenated alkyl having 1 to 5 C atoms, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy.

24. The polymerisable LC material according to claim 1 or 2, wherein the concentration of the chiral compound in the liquid crystal medium is in an amount of 1 to 20%.

25. The polymerisable LC material according to claim 1 or 2, comprising one or more additives selected from the group consisting of additional surfactants, photoinitiators, stabilisers, catalysts, sensitisers, inhibitors, chain transfer agents, co-reactive monomers, reactive viscosity reducers, lubricants, wetting agents, dispersants, hydrophobic agents, binders, flow improvers, degassing agents or defoaming agents, diluents, colourants and nanoparticles.

26. A method for preparing a polymerisable LC material according to any one of claims 1 to 25, comprising the following steps: One or more block copolymers as defined in claim 1 are mixed with one or more reactive mesogenic compounds and one or more chiral compounds.

27. A method for preparing a polymer film, the method being achieved by: - providing a layer of polymerisable LC material according to any one of claims 1 to 25 onto a substrate, - photopolymerizing the polymerizable LC material, and - optionally removing the polymerized LC material from the substrate and / or optionally providing it onto another substrate.

28. A polymer film obtainable from the polymerisable LC material according to any one of claims 1 to 25 by a process comprising the steps of: - providing a layer of said polymerisable LC material onto a substrate, - photopolymerizing the LC material, and - Optionally, removing the polymerized LC material from the substrate and / or optionally providing it onto another substrate.

29. Use of one or more polymer films according to claim 28 or polymerisable LC materials according to any one of claims 1 to 25 in an optical component.

30. An optical component comprising one or more polymer films according to claim 28 or a polymerisable LC material according to any one of claims 1 to 25.

31. Use of the optical component according to claim 30 in an electro-optical device.

32. An electro-optical device comprising an optical component according to claim 29 or one or more polymer films according to claim 28 or a polymerisable LC material according to any one of claims 1 to 25.

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