GB2383040A - Multiblock compounds comprising hydrocarbon moiety & fluorocarbon, siloxane, or oligo- or poly(oxaalkylene) moiety as an additive in liquid crystal materials - Google Patents

Abstract

Compounds having a multiblock structure are disclosed which comprise at least one first block, comprising an aliphatic, alicyclic, aromatic or araliphatic hydrocarbon group ("hydrocarbon block"), and at least one second block, comprising a fluorocarbon, siloxane or oliogo- or poly(oxaalkylene) group ("surfactant block") provided such compounds comprise either at least two hydrocarbon blocks or at least one hydrocarbon block comprising a cyclic group. The compounds may be added to liquid crystal materials (eg polymerisable films) and used to control the orientation of such materials at the material/substrate and/or material/air interface, to promote adhesion between such materials and the substrate and/or subsequent liquid crystals or polymer layers, or to promote wetting of the substrate and/or other layers. In the examples, the surfactant block comprises -(CF 2 ) n - (where n is from 6 to 10) or a 2,3,5,6-tetrafluoro-1,4-phenylene and the hydrocarbon block comprises a branched alkyl group, phenyl or 4-substituted phenyl.

Description

J - 1 Compounds with Multiblock Structure Field of the Invention

5 The invention relates to compounds having a multiblock structure, to methods of their preparation, to their use as surfactants, aligning, adhesion promotion or wetting agents in particular in liquid crystal materials, and to liquid crystal materials and polymer films comprising the inventive multiblock compounds.

Background and Prior Art

Liquid crystal materials have for many years found widespread use, particularly in display applications. In order to make use of their 15 anisotropic physical and optical properties, it is usually necessary that the liquid crystal material is macroscopically aligned into a monodomain. This is most conveniently achieved by the use of a suitable aligning layer on the supporting substrate, most often a rubbed polymer such as polyimide or PVA. In many cases, for example in the manufacture of a liquid crystal 20 display, a thin layer of liquid crystal material is prepared between two such substrates with aligning surfaces, and the surface alignment propagates through the bulk of the material to give the desired uniform alignment of the bulk. Typically this can be planar alignment (i.e. the long axis of the molecules essentially parallel to the substrates), but it may also be 25 homeotropic alignment (perpendicular to the substrates) or tilted alignment (intermediate between planar and homeotropic), or a combination of these. In all cases the macroscopic alignment can effectively be controlled by the appropriate choice of alignment layer on the two substrates.

However, in some situations it is desirable that the aligned layer of liquid crystal material is prepared on a single substrate, for example in the coating of a thin film of a liquid crystal material containing liquid crystal or mesogenic compounds with polymerisable groups (hereinafter also 35 referred to as Reactive mesogensn) whereby subsequent polymerization allows the formation of a coherent polymer network. In this case it is only

- 2 possible to utilise an alignment layer at one of the liquid crystal surfaces, the other inevitably being an open surface, and the overall alignment through the bulk is then partially determined by the natural ordering of the liquid crystal molecules at the air interface. To some extent this can be 5 controlled by the structure of the liquid crystal materials themselves.

It is also known in prior art to use surface active (surfactant) additives or

mixtures to promote planar orientation of LC materials on single substrates, with one surface of the LC open to the air. This is disclosed for 10 example in WO 99/45082 and US 5,995,184, which report the use of surfactants to promote planar orientation in the preparation of a film of polymerised LC material with an open surface. WO 99/45082 reports the use of short chain, mixed fluorocarbon / hydrocarbon surfactants. US 5,995, 184 reports the use of polymeric molecules as surfactants, like 15 polyacrylates, polysilicones and organosilanes. In each case the average tilt angle at the open surface of LC films can be tailored from an inherent tilt angle, which depends on the material composition and the substrate, to approximately 0 by variation in the amount of surfactant that is added.

20 The use of short chain, mixed fluorocarbon/hydrocarbon surfactants is usually favoured because their lower surface energy results in a greater reduction in the surface tension of the mixture for a given concentration of surfactant. For example, typical values for the surface tension of hydrocarbon, silicone and fluorochemical surfactants are 2 25, 20 - 35 and 25 16 - 20 moms respectively [L. Gehlhoff Fluorosuffactants for Paint and Coatings, product information of 3M Inc., St. Paul, Minnesota, USA]. The low surface tension of these fluorochemical surfactants has been widely utilised, for example in levelling agents for coatings lL. Gehlhoff Fluorosuffactants for Paint and Coatings, product information of 3M Inc., 30 St. Paul, Minnesota, USA] and water repellent treatments [see US 5,216,097, US 5,344,956].

Molecules with a low surface energy readily accumulate at the LClair

interface promoting the orientation effect as reported for example in US 35 5,344,956. In practice, once polymerised the LC films may be part of a composite LC cell, in which other layers need to be added to the polymer

- 3 LC film, such as, but not restricted to, other liquid crystal, retardation or barrier layers etc.. However, the polymerised LC films containing fluorocarbon surfactants, which are rich in fluorocarbon molecules at their surface, have a low surface energy which frequently leads to problems in 5 the coating of subsequent layers due to de-wetting. Moreover, when it is possible to successfully coat a second layer, the adhesion of the second layer to the polymerized LC film is often very poor as a result of the low surface energy of the first layer. In addition, the surfactant molecules also tend to migrate to the lower interface, leading to poor adhesion of the LC 10 film to the substrate.

It is an aim of the present invention to provide additive materials that achieve the desired--alignment at the air interface of an LC layer, but without the associated problems of de-wetting and low adhesion that are 15 found in the prior art materials as described above. Further aims of the

invention are immediately evident from the following description.

It was found that these aims can be achieved by providing compounds having a multiblock structure as described in the present invention.

Summary of the Invention

One object of the present invention is a compound having a multiblock structure, comprising at least one first block comprising an aliphatic, 25 alicyclic, aromatic or araliphatic hydrocarbon group (hydrocarbon block) and at least one second block comprising a fluorocarbon, siloxane or oligo- or poly(oxaalkylene) group, characterized in that the compound comprises at least two hydrocarbon blocks andlor at least one hydrocarbon block comprising a cyclic group Another object of the present invention is the use of the multiblock compounds as surfactant, aligning, adhesion promotion or wetting agent in liquid crystal materials.

35 Another object of the present invention is the use of the multiblock compounds in a layer of liquid crystal material provided on a substrate, to

- 4 promote alignment of the liquid crystal material at the substrate or at the open surface, and/or to promote adhesion between the liquid crystal material and the substrate or between the liquid crystal material and subsequent liquid crystal layers, and/or to promote wetting of the 5 substrate.

Another object of the present invention is a method in a liquid crystal material provided on a substrate to control the alignment of the liquid crystal molecules at the substrate and/or at the open surface, by adding 10 one or more multiblock compounds according to the invention to the liquid crystal material.

Another object of the present invention is a method to control alignment as described above, wherein the alignment is parallel, homeotropic, tilted, 15 splayed, twisted or bent alignment.

Another object of the present invention is a liquid crystal material comprising one or more mesogenic or liquid crystal compounds and at least one multiblock compound according to the invention.

Another object of the present invention is a polymerisable liquid crystal material comprising one or more mesogenic or liquid crystal compounds and at least one multiblock compound according to the invention, and comprising at least one polymerisable compound which can be one of 25 said multiblock, mesogenic or liquid crystal compounds or an additional compound. Another object of the present invention is an anisotropic polymer film obtained by providing a layer of polymerisable liquid crystal material 30 according to the invention on a substrate, and polymerising the material that is aligned in its liquid crystal phase, wherein the alignment of the liquid crystal molecules at the substrate and/or at the open surface is controlled by appropriate selection of the multiblock compounds according to the invention that are present in the polymerisable material.

- 5 Another object of the present invention is a multilayer anisotropic polymer film comprising two or more polymerized layers prepared according to the invention, wherein second and higher numbered layers, in the sequence of their preparation, are prepared on the first or previous layers serving as 5 a substrate, and wherein the adhesion between adjacent layers is controlled by appropriate selection of the multiblock compounds according the invention that are present in the layers.

Another object of the present invention is a liquid crystal material 10 comprising one or more mesogenic or liquid crystal compounds and at least one multiblock compound according to the invention, wherein at least one of said multiblock compounds comprises a photoisomerisable group that undergoes isomerisation, thereby changing its structure, upon photoradiation. Another object of the invention is a liquid crystal material comprising a multiblock compound with a photoisomerisable group as defined above, wherein the different isomeric structures of the photoisomerisable compound promote different alignment directions in the liquid crystal material.

Another object of the present invention is a patterned anisotropic polymer film comprising a polymerised liquid crystal material with uniform alignment, having a pattern of at least two areas of different alignment direction, obtained by 25 - providing a layer of a polymerisable liquid crystal material comprising at least one photoisomerisable compound as defined above on a substrate, - exposing selected areas of the layer to photoradiation that induces 30 isomerisation in the photoisomerisable compound, thereby changing the tilt of the liquid crystal material in the exposed areas at the air interface, and - polymerising the selected areas and/or the entire layer to fix the alignment.

- 6 Another object of the present invention is the use of a liquid crystal material or polymer film according to the invention in active or passive optical devices like liquid crystal displays, polarisers, compensators, colour filters, alignment layers, beam splitters, birefringent, coloured or patterned 5 films for use in optical, decorative and security applications, security markings, holographic images, hot stamping foils and for the preparation of liquid crystal pigments, further as oriented films with charge transport or semiconductor properties in optical or electronic devices, like field effect

transistors as components of integrated circuitry, thin flm transistors in flat 10 panel display applications or for REID (Radio Frequency Identification) tags, semiconducting components for OLED (organic light emitting diode) applications, electroluminescent display devices, backlights, photovoltaic or sensor devices, electrode materials in batteries, photoconductors and electrophotographic applications.

Brief Descrintion of the Drawinas Figure 1 shows the retardation profile (optical retardation versus viewing angle) of a polymer film obtained from polymerisable Mixture 1 according 20 to example 6 of the present invention.

Figure 2 shows the retardation profile of a polymer film obtained from polymerisable Mixture 2 according to example 6 of the present invention.

25 Figure 3 shows the retardation profile of a polymer film obtained from polymerisable Mixture 3 according to example 6 of the present invention.

Detailed Descriotion of the Invention 30 The compounds according to the present invention are particulary useful as additives to control the specific orientation of LC materials at open surfaces. Furthermore, they afford improved adhesion of a polymerised LC layer to subsequent LC or polymer layers. For this purpose, they are designed to contain one or more blocks comprising a fluorocarbon, 35 siloxane or oligo- or poly(oxaalkylene) groups, hereinafter also shortly referred to as "surfactant block" or "surfactant chain", and one or more,

- 7 preferably more than one block comprising an aliphatic, alicyclic, aromatic or araliphatic hydrocarbon group, hereinafter also shortly referred to as "hydrocarbon block" or"hydrocarbon chain".

5 By correct design of the molecular structure of the inventive compounds, it is possible for example to promote specific orientation of the LC molecules at the air interface (for example homeotropic, planar or an intermediate tilted orientation). Subsequent polymerization of the LC layer fixes the molecular orientation, and the resultant polymer film may be used, for 10 example, as an optical retardation layer. If the LC material possesses a cholesteric phase, the inventive materials may be used for obtaining the planar cholesteric alignment necessary to produce a bright selective reflection-of-light. Such-layers-may be used-as polarising reflectors, colour filters, in optical data storage or in security and decorative applications.

When used as surfactants, the compounds of the present invention due to the presence of the surfactant chain concentrate at the interfaces of the LC layer. Through the-incorporation of specific functionality into the hydrocarbon chain the inventive compounds can be engineered to control 20 various physical aspects of the LC molecules at the air surface, for example it is possible to promote specific interactions such as hydrogen bonding, dipole interactions etc.. This functionality can, for example, be used to overcome the problem of poor adhesion and dewetting that occurs when using the prior art surfactant materials between the surfactant rich

25 interface and a subsequent hydrocarbon based organic layer. For example, the incorporation of polar nitrile groups in the compound 24 of example 2 of this invention enables a polymerized film, prepared from a mixture containing compound 24, to be wetted by another hydrocarbon layer. It may also be used to control the orientation of a subsequent LC 30 layer when coated onto the first layer after polymerization.

In another variation, the inventive compounds also contain one or more photoisomerisable groups that are sensitive to irradiation by light of visible or UV wavelengths, and which thereby undergo a change of molecular 35 shape, for example, by a trans-cis isomerisation of a double bond. By correct choice of molecular design, the irradiated species can have

- 8 different chemical or physical properties to the non-irradiated form, such as, for example, stabilising a different tilt angle of the LC molecules at the air interface. The irradiation process then provides a switching mechanism between the two possible orientations, and by irradiation through a 5 suitable mask, patterning of the surface orientation is possible.

In a preferred embodiment of the present invention, the multiblock compound contains one or more photoisomerisable groups in the hydrocarbon block. These groups are chosen from the range of such 10 groups already known, that have the property of undergoing cis/trans isomerisation on exposure to UV radiation. Examples of useful groups include azobenzene, cinnamate and stilbene. As a result of the isomerisation,-the shape-of the hydrocarbon- part of-the mole-cure is changed, thereby affecting the alignment angle at the surface. By 15 irradiation through a mask the surface alignment can be patterned to create discrete regions of different alignment through the bulk of the film.

For example, a polymerisable nematic LC mixture containing an inventive multiblock compound that promotes planar alignment is coated onto a 20 rubbed polyimide surface to give a film with a macroscopic, uniform planar alignment. The film is irradiated through a grey scale mask with a chequer board pattern (in the presence of air to inhibit photo- polymerisation) such that some areas are exposed to UV radiation, and others are not. In the areas that do receive UV exposure the photoisomerisable group of the 25 surfactant undergoes cis/trans isomerisation and the surface alignment changes from planar to tilted in these regions, causing the bulk alignment to change from planar to splayed. Subsequent photopolymerisation under an inert atmosphere fixes the structure. Such films are useful for example as retarders in multidomain LCD's or, patterned cholesteric films for 30 decorative I security use.

In a further variation, the inventive compounds contain one or more polymerisable groups, so that in subsequent polymerization of the LC layer the additive material becomes chemically bound into the layer. This 35 prevents subsequent migration of the additive material into any further layer that is coated onto the LC layer following the polymerization.

- 9 - In the following, some structures of suitable multiblock compounds according to the present invention are exemplarily described. These structures are intended to sufficiently demonstrate the effects of the 5 present invention, however, they should not be construed as a complete list of such suitable compounds, nor are they intended to limit the scope of this invention.

Thus, for example multiblock compounds with other surface active chains 10 than those specifically shown below are also suitable as additives for the applications described in this invention. Also, the number and structure of possible hydrocarbon chains is not restricted to the structures as specifically shown below and in-th-e examples of this invention. The basic idea is applicable to a wide variety of hydrocarbon aliphatic and aromatic 15 chains, provided the chain is long enough to promote miscibility with the LC and not too long that the solubility limit is reached. Also, the choice of a suitable hydrocarbon chain depends on the intended application.

For example, to promote planar alignment the hydrocarbon chains are 20 preferably chosen such that the difference in their surface energies is small, the ideal case being that the hydrocarbon chains are identical, causing the multiblock compound to orient parallel to the substrate at the air interface and hence promoting planar orientation. For example, compounds 11 - 12, 14 - 15, 17 - 18 and 20 - 22 of example 2 of this 25 invention are all symmetrical compounds, i.e. they contain identical hydrocarbon chains, and all are found to promote planar orientation in a film of polymerisable LO material according to the invention. Compound 26 of example 2 is not a symmetrical compound but still promotes planar orientation in such a film. This is rationalised because the terminal 30 hydrocarbon chains have only a small difference in their surface energies, 29 mNm ' for benzene compared to 31 mNm ' for the combined contribution from cyclohexane (25 mNm ') and pentane (16 mNm ') lsee J. Jasper Whys. Chem. Ref. Data 1, 841-1009 (1972)1.

35 To promote homeotropic orientation the multiblock compound can for example be constructed such that there is a large difference in surface

- 10 energies of the terminal groups. For example, the non-symmetric compounds 1-9 of example 1 of this invention promote homeotropic orientation and contain terminal groups with a large difference in surface energies. The alkyl groups have a typical surface energy of at least 29 5 mNm ' (benzyl group without further substitution) whereas the methylalcohol group has a surface energy of 22.5 mNm ' [see J. Jasper Phys. Chem. Ref. Data 1, 841-1009 (1972)].

Alternatively it is possible to modify the multiblock compound inducing 10 planar alignment by incorporating bulky terminal groups such that they template homeotropic or tilted orientation at the air interface. For example the geometry adopted by the hydrocarbon chains, with respect to the more-rigid fluorocarbon-chain-,-as-shown exemplarily-in the compounds 19 and 23 of example 2 of this invention, directly influences the tilt angles at 15 the air interface of a film of polymerisable LC material according to the invention. Although these materials are symmetrical, the templating effect of the hydrocarbon groups induces a tilt angle at the air surface of 87 and 71 respectively.

20 It is also possible to design the multiblock compounds according to the present invention such that they induce a first alignment, for example planar alignment, in a first layer of a polymerised LC mixture containing the multiblock compound, but induce a different alignment, for example homeotropic alignment, in a subsequent layer of polymerised LC material 25 that is prepared on said first layer, or vice versa. In this way a multilayer can be prepared wherein the alignment direction varies between the adjacent single layers.

The terminal chains of the multiblock compounds can also be modified to 30 incorporate a reactive group, like for example an acrylate or methacrylate group, to enable them to be polymerized into the LC film and to prevent their migration into subsequent layers.

Especially preferred are triblock compounds with one surFactant block and 35 two hydrocarbon blocks. However, further to triblock compounds, multiblock compounds with more than three blocks can also provide, for

l - 11 example, good orientation and improved adhesion to a subsequent layer, provided the material is soluble in the LO and the balance of chain length of the surface active and hydrocarbon parts is maintained to produce a surface active molecule. In this way, pendant groups can be incorporated 5 into specific hydrocarbon regions and used to influence either the underlying LC or a subsequent layer.

The multiblock compounds of the present invention can be ionic or non ionic compounds. Especially preferred are nonionic compounds.

Preferably the inventive compounds comprise 3 to 5 hydrocarbon blocks and 1 to 4 blocks comprising a fluorocarbon, siloxane or oligo- or poly(oxaalkylene)--group. 15 Especially preferred are compounds selected of formula I Cn((B C2)a B C)n wherein B is a bivalent block comprising a fluorocarbon, siloxane or oligo- or poly(oxaalkylene) group, C' is in each case independently of one another a monovalent 25 hydrocarbon block, or, in case one or more of C2, C" or the other groups C' contain a cyclic group, may also denote H. C2 is in each case independently of one another a bivalent hydrocarbon block, C" is an n-valent hydrocarbon block, n is an integer from 1 to 6, and 35 a isO, 1,2,30r4.

- 12 Especially preferred compounds of formula I are those selected from the following subformulae C1 B (C2 B) C1 1-1

1 2 B 3 1

C -B-(C-)b-C (B-C)2 1-2 C4(B-C1)4 1-3

10 wherein B. Ci, C2 and a have the meaning of formula 1, C3 iS a trivalent hydrocarbon block, C4 iS a tetravalent hydrocarbon block, and b isOor1.

The blocks B comprising a fluorocarbon, siloxane or oligo- or poly(oxaalkylene) group are preferably selected from the following formulae Q-(CF2)c Q 11-1 25 +> Q 11-2

F F 30 T O (CH2CH20)e (CH2CH2CH20)f T 11-3 Y-(SiR1 R2-O)g-SiR1 R2-Y l lot wherein

- 13 Q is -CH2O-, -OCH2-, -CH2S-' -SCH2-, -CH2-O-CO-N R -, -N R CO-O-C H2-, -C H2-O-CO-O-, -O-CO-OC H2-, -CO-O- 1 -O-CO-,

CO-S-, -S-CO-, -CO-NR - or-NR -CO-, 5 T is -CO-' -CO-O-J -O-CO-, -CO-NR or -NR -CO-, Y is -CH20-, -OCH2- or-CH2CH2-, R is H or alkyl with 1 to 12 C-atoms, R' and R2 are independently of each other H or an aliphatic, alicyclic, aromatic or araliphatic group with 1 to 10 C-atoms, c is an integer from 2 to 20, d is an integer from 1 to 4, e and f are independently of each other an integer from O to 25, with e + f = 2 to 30, and g is an integer from 1 to 10.

Very preferably the blocks B comprising a fluorocarbon, siloxane or oligo or poly(oxaalkylene) group are selected from the following formulae -OCH2(CF2)C-CH20- 11-1a -COO-(CF2)c-OCO- 11-1 b 30 -NH-COO-(CF2)C-OCO-NH- 111c -OCO-(CF2)C-COO- 11-1 d -NH-CO-(CF2)C-CO-NH- 11-1e -CH20-(CH2CH20)eCH2- 11-3a

- 14 -CH20-(CH2CH2CH20)e CH2 11-3b -COO-(CH2CH2O)e-CO- 1 1-3c -COO(CH2CH2CH2O)e-CO- 11-3d -NH-COO-(CH2CH2O)e-CO-NH- 11-3e 10 N H-COO(CH2CH2CH2O)e-CO-NH- 1 1-3f -CH2-O-(Si(CH3)2-O)g-Si(CH3)2-O-CH2- 11 a CH2- CH2-O-(Si(CH3)2-O)g-Si(CH3)2-O-CH2-CH2- 114b wherein c is preferably 8, 9 or 10, e is preferably an integer from 3 to 14, and g is preferably an integer from 1 to 10.

The hydrocarbon blocks On, C', C2, C3 and C4 are preferably selected 20 from H. straight-chain or branched alkyl, or comprise up to four of each of the sub-units Sp, X, A and R which may be connected in a linear or branched manner, wherein Sp is an n-valent spacer group or a single bond, X is-O-,-S-,-CO-,-COO-,-OCO-,-CO-S,-S-CO-,-O-COO-, CO-NR -,-NR -CO-, OCH2-, -CH2o-t -SCH2-, -CH2S-, CF20-, -oCF2-' -CF2S-, -SCF2-, -CH2CH2-, CF2CH2-' CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CH-,

30 CF=CH-,-CH=CF-,-CF=CF-,-C_C-,-CH=CH-COO-,-OCO

CH=CH- or a single bond, A is an n-valent 5- or 6-membered aromatic or carbocyclic group which may also contain one or more hetero atoms, 35 may be connected to neighboured groups in any of the 1-, 2

- 15 3-, 4-, 5- or 6-position, and may be substituted by one or more groups L or P-Sp-X, L is halogen or a cyano, nitro, alkyl, alkoxy, alkylcarbonyl or 5 alkoxycarbonyl group with 1 to 7 C atoms, wherein one or more H atoms may be substituted by F or Cl, R is H. F. Cl, Br, I, ON, SON, SF5H, NO2, or n-valent straight chain, branched or cyclic alkyl with 1 to 20 C-atoms, which 10 may be unsubstituted, mono- or poly-substituted by F. Cl, Br, I or ON, it being also possible for one or more nonadjacent CH2 groups to be replaced, in each case independently from one another, by-O-, -S-, -NH-, -NR -, -SiR R -, -CO-, -COO -OCO-, -OCO-O-, S-CO-, -CO-S-, -CH=CH- or-C_C- in 15 such a manner that O and/or S atoms are not linked directly to one another, or denotes P-Sp-X, P is a polymerisable group, 20 R and R are independently of each other H or alkyl with 1 to 12 C atoms, and n is an integer from 2 to 6.

25 Preferably at least one of the hydrocarbon blocks On, C', C2, C3 and C4 comprises a group of formula lil Sp-X'-A'-(Z-A2)m-R. 111 30 wherein X' is-O-,-S-,-OCH2-,-CH20-,-CO-,-COO-,-OCO-,-CO-S-,-S CO-, -OCO-O-, -CO-NR -, -NR -CO-, -OCH2-, -CH20-, -SCH2-,

-CH2S-, -CH=CH-COO-, -OOC-CH=CH- or a single bond, A' and A2 independently of each other have one of the meanings of A,

- 16 Z is-O-,-S-,-CO- -COO- -OCO-'-CO-S- -S-CO-,-O-COO- -

CO-NR -' -N R -CO-, -OCH2-, -CH20-l -SCH2-, -CH2S-, -CF2O -OCF2-, -CF2S-, -SCF2- -CH2CH2-l -CF2CH2-, -CH2CF2-l 5 CF2CF2- -CH=N- -N=CH-,-N=N-,-CH=CH1-CF=CH-1

CH=CF-, -CF=CF-, -C_C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond, m is 0, 1, 2 or 3, and Sp, X, R. R , R , P. L and have the meanings given above.

Very preferably at least one of the hydrocarbon blocks On, C', C2, C3 and C4 comprises a group selected from the following formulae A-R 1111

A'-A2-R 1112

Ai-OCO-A2-R 1113 A'-COO-A2-R 1114

20 A'-O A2 R 1115

A'-CH2O-A2-R 1116

A'-OCH2-A2-R 1117

A'-CH2CH2-A2-R 1118

A'-A2 A2 R 1119

25 A'-OCo-A2-A2-R 11110 A'-Coo-A2-A2-R 11111 A4-COO-A2-CH2CH2-A2-R 1111 2

A4-OCO-A2-CH2CH2-A2-R 11113

A'-CH2CH2-A2-COO-A2-R 11114

30 A'-CH2CH2-A2-OCO-A2-R 11115

A'-COO-A2 COO-A2-R 11116

A4-COO-A2 OCO-A2-R 11117

A'-OCO-A2 OCO-A2-R 11118

A'-CH2CH2-A2-CH2CH2-A2-R 11119

- 17 (CH2)h-H C\ IV (CH2)j H wherein A', A2, R have the meanings given above, and h and i are identical or different integers from O to 20.

Especially preferred are compounds selected from the following formulae RA'-(Z-A2)m-X'-Q-(CF2)C-Q-H V-1 15 R-A1-(Z-A2)m-X1-Q Q-H V-2 F F (CH2)h-H\ /(CH2)h-H 20 /C-Q-(CF2)C-Q-C\ V-3

(CH2), H (CH2),-H

R-A'-(Z-A2)m-X1-Q-(CF2)C-Q-X1-(A2-z)m-A1-R V4 25 F F

R-A1-(Z-A2)m-X'-Q Q-X1-(A2-Z)m-A'-R V-5 F F wherein R. A1, A2, Z. X', Q. c, d, h, i and m have the meanings given above. In the above formulae, A, A' and A2 are preferably selected from phenyl in 35 which, in addition, one or more CH groups may be replaced by N. cyclopentane or cyclohexane in which, in addition, one or two non

- 18 adjacent CH2 groups may be replaced by O and/or S, thiophenelthiazole, thiadiazole, dioxolane, cyclohexene, piperidine, indane, benzofuran, benzo[b]thiophene, benzooxazole, benzothiazole, naphthalene, decahydronaphthalene' tetrahydronaphthalene, it being possible for all 5 these groups to be unsubstituted, mono- or polysubstituted with L. Especially preferably A, A' and A2 are selected from the following groups: = 0} 0 0

20 I\ IN

25 IN IN

: -No b ó

- 19 5 INN INN I,

to 3:1 Particularly preferred are compounds wherein the group A,-(Z-A2)m is 15 selected from the group of formulae listed below. For reasons of simplicity, Phe in these formulae is 1,4-phenylene that may also be substituted with 1 to 4 groups L as defined above, Cyc is 1,4cyclohexylene and Z has one of the meanings of formula lilt The list is comprising the following subformulae as well as their mirror images -PheZ-Phe- Vl-1 -Phe-Z-Cyc- Vl-2 -Cyc-Z-Cyc- Vl-3 -Phe-Z-Phe-Z-Phe- Vl4 25 Phe-Z-Phe-Z-Cyc- Vl-5 -Phe-Z-Cy>Z-Phe- Vl-6 -Cyc-Z-Phe-Z-Cyc- Vl-7 -Phe-ZCyc-Z-Cyc- Vl-8 -Cyc-Z-Cyc-Z-Cyc- Vl-9 Particularly preferred are the subformulae Vl-1, Vl-2, Vl, Vl-5 and Vl-6.

Very preferably the group A'-(Z-A2)m is selected from the following formulae and their mirror images

- 20 (L)r (L)r Vla 5 (L)r 0 Vlb Vlc (L)r (L)r 15 COO Vld (L)r (L)r 20 CH2CH2 Vle (Ll)r j)r = > Vlf (L)r (L)r (L)r Vlg (L)r (L)r (L)r tCOO Vlh

- 21 (L)r (L)r (L)r HOOCH Vli 5 (L)r (L)r COO Vlk COO:OOCt Vlm (L)r (L)r (L)r 15 COO:COO Vln (Ll)r - ( IL)r (lL)r 20 OOC SCOOT Vlo (L)r (L)r (L)r 25 CH2CH2 CH2CH2 Vlp (L)r (L)r (L)r ≤óOOC Vlq OOC OOC Vlr

b - 22 wherein L and r have the above meanings, and r is preferably 0, 1 or 2.

(L)r The group {A in these preferred formulae is very preferably 5 L L L L L

denoting {A or furthermore {A with having each independently one of the meanings given above.

Particularly preferred are the subformulae Vld, Vlg, Vlh, Vli, Vim, Vln and Vlo, in particular the subformula Vld.

In the above formulae, L is preferably F. Cl, CN, NO2, CH3, C2H5, OCH3, 15 OC2Hs, COCH3, COC2H5, COOCH3, COOC2Hs, CF3, OCF3, OCHF2 or OC2F5, in particular F. Cl, CN, CH3, C2H5, OCH3, COCH3, CF3 or OCF3, most preferably F. Cl, CH3, OCH3 or OCF3.

Z is preferably -COO-, -OCO-, -CH2CH2-, -CH2O-, -OCH2- or a single 20 bond.

If R is an alkyl or alkoxy radical, i.e. where the terminal CH2 group is replaced by -O-, this may be straight-chain or branched. It is preferably straight-chain, has 2, 3, 4, 5, 6, 7 or 8 carbon atoms and accordingly is 25 preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, or octoxy, furthermore methyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, nonoxy, decoxy, undecoxy, dodecoxy, tridecoxy or tetradecoxy, for example.

30 Especially preferred is straight chain alkyl or alkoxy with 1 to 8 C atoms.

Oxaalkyl, i.e. where one CH2 group is replaced by-O-, is preferably straight-chain 2-oxapropyl (=methoxymethyl), 2- (=ethoxymethyl) or 3 oxabutyl (=2-methoxyethyl), 2-, 3-, or 4-oxapentyl, 2-, 3-, 4-, or 5oxahexyl, 35 2-, 3-, 4-, 5-, or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyl or 2-, 3-, 4-, 5-, 6-,7-, 8- or 9-oxadecyl, for example.

- 23 R can be a polar or an unpolar group. In case of a polar group, it is preferably selected from CN, NO2, halogen, OCH3, SON, CoR3, CoOR3 or a mono- oligo- or polyfluorinated alkyl or alkoxy group with 1 to 4 C 5 atoms. R3 is optionally fluorinated alkyl with 1 to 4, preferably 1 to 3 C atoms. Especially preferably polar groups are selected of F. Cl, CN, NO2, OCH3, COCH3, COC2H5, COOCH3, COOC2Hs, CF3, C2F5, OCF3, OCHF2, and OC2F, in particular of F. Cl, CN, OCH3 and OCF3. In case of an unpolar group, it is preferably alkyl with up to 15 C atoms or alkoxy with 2 10 to 15 C atoms.

R can be an achiral or a chiral group. In case of a chiral group, it is preferably selected according to formula Vll: 1 5 -Z'-Q'-CH-O2

Q3 Vl1 wherein Z' is -O-, -S-, -CO-, -COO-, -OCO-, -OCOO- or a single bond, Q' is an alkylene or alkylene-oxy group with 1 to 9 C atoms or a single bond, Q2 is an alkyl or alkoxy group with 1 to 10 C atoms which may be unsubstituted, mono- or polysubstituted with halogen or CN, it being also possible for one or more non-adjacent CH2 groups to be replaced, in each case independently from one another, by 30 -C_C-, -O-, - S-, -NR -, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO- or CO-S- in such a manner that oxygen atoms are not linked directly to one another, Q3 is halogen, a cyano group, an alkyl or alkoxy group with 1 to 4 C 35 atoms different from Q2, or a phenyl group that may also be mono- or polysubstituted with L as defined in formula 1.

- 24 In case Q, in formula Vll is an alkylene-oxy group, the O atom is preferably adjacent to the chiral C atom.

5 Preferred chiral groups are 2-alkyl, 2-alkoxy, 2-methylalkyl, 2 methylalkoxy, 2-fluoroalkyl, 2-fluoroalkoxy, 2-(2-ethin)-alkyl, 2-(2ethin) alkoxy, 1,1,1-trifluoro-2-alkyl, 1,1,1-trifluoro-2-alkoxy, 2phenylalkyl, 2 phenylalkoxy, 2-phenylcarbonyl, 2-phenylcarbonyloxy and 2 phenyloxycarbonyl. Particularly preferred chiral groups are 2-butyl (=1methylpropyl), 2 methylbutyl, 2-methylpentyl, 3-methylpentyl, 2ethylhexyl, 2-propylpentyl, in particular 2-methylbutyl, 2-methylbutoxy, 2-methylpentoxy, 3 methylpentoxy, 2-ethylhexoxy, 1-methylhexoxy, 2octyloxy, 2-oxa-3 15 methylbutyl, 3-oxa4-methylpentyl, 4-methylhexyl, 2hexyl, 2-octyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-methoxyoctoxy, 6methyloctoxy, 6 methyloctanoyloxy, 5-methylheptyloxycarbonyl, 2methylbutyryloxy, 3 methylvaleroyloxy, 4-methylhexanoyloxy, 2chlorpropionyloxy, 2-chloro-3 methylbutyryloxy, 2-chloro4methylvaleryloxy, 2-chloro-3 20 methylvaleryloxy, 2-methyl-3-oxapentyl, 2methyl-3-oxahexyl, 1 methoxypropyl-2-oxy, 1-ethoxypropyl-2-oxy, 1propoxypropyl-2-oxy, 1 butoxypropyl-2-oxy, 2-fluorooctyloxy, 2fluorodecyloxy, 1,1,1-trifluoro-2 octyloxy, 1,1,1-trifluoro-2-octyl, 2fluoromethyloctyloxy, 2-phenylbutyl, 2 phenylbutyloxy, 2phenylpropylcarbonyl, 2-phenylpropylcarbonyloxy for 25 example. Very preferred are 2-hexyl, 2-octyl, 2-octyloxy, 1,1,1-trifluoro-2 hexyl, 1, 1, 1-trifluoro-2-octyl and 1, 1,1-trifluoro-2-octyloxy, for example.

In addition, compounds containing an achiral branched group R may occasionally be of importance, for example, due to a reduction in the 30 tendency towards crystallization. Branched groups of this type generally do not contain more than one chain branch. Preferred achiral branched groups are isopropyl, isobutyl (=methylpropyl), isopentyl (=3-methylbutyl) , isopropoxy, 2-methyl-propoxy and 3-methylbutoxy.

35 R and R are preferably H or CH3, in particular H.

- 25 Halogen is preferably F or Cl.

The polymerisable group P is preferably selected from CH2=CW'-COO-, 5 W2HC-CH- W2 (CH2)k- -, CH2=CW2-O-, CH3-CH=CH-O-.

Ho-CW2W3-, HS-CW2W3-, HW2N-, Ho-CW2W3-NH-, CH2=CW'-CO-NH-, CH2=CH-(COO)k'Phe-(O)k2-, Phe-CH=CH-, HOOC-, OCN- and W4W5W6Si-, with W1 being H. Cl, ON, phenyl or alkyl with 1 to C-atoms, 10 in particular H. Cl or CH3, W2 and W3 being independently of each other H or alkyl with 1 to 5 C-atoms, in particular methyl, ethyl or n-propyl, W4, W5 and w6 being independently of each other Cl, oxaalkyl or oxacarbonylalkyl with 1 to 5 C-atoms, Phe being 1,4-phenylene and k, and k2 being independently of each other 0 or 1.

P is particularly preferably an acrylate, methacrylate, vinyl, vinyloxy, epoxy, styrene or propenyl ether group, in particular an acrylate, methacrylate, vinyl or epoxy group.

20 As for the spacer group Sp all groups can be used that are known for this purpose to those skilled in the art. The space group Sp is preferably a straight chain or branched alkylene group having 1 to 20 C atoms, in particular 1 to 12 C atoms, in which, in addition, one or more non-adjacent CH2 groups may be replaced by-O-, -S-, -NR -, -CO-, -O-CO-, S-CO-, 25 O-COO-,-CO-S-,-CO-O-,-CH(halogen)-,-C(halogen)2,-CH(CN)-, CH(OH) -, -CD2-, -CH=CH-, -CF=CF-, -CH=CF- or -C_C-, or a siloxane group, and in which one or more H atoms may be replaced by halogen, CN or OH.

30 Typical spacer groups are for example -(CH2)o-, -(CH2CH2O)p-CH2CH2-, CH2CH2-S-CH2CH2- or -CH2CH2-NH-CH2CH2-, or -(SiR R -O)q-, with o being an integer from 2 to 12, p being an integer from 1 to 3, q being an integer from 1 to 3, and R and R having the meanings given above.

35 Preferred spacer groups are ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene,

( - 26 dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylene-thioethylene, ethylene-N-methyliminoethylene, 1-

methylalkylene, ethenylene, propenylene and butenylene for example.

5 Especially preferred are inventive compounds wherein Sp is denoting alkylene or alkylene-oxy with 2 to 8 C atoms. Straight-chain groups are especially preferred: Further preferred are compounds comprising at least one spacer group Sp 10 that is a chiral group of formula Vat: -Q'-CH-Q4

Q3 V111

wherein Q' and Q3 have the meanings given in formula Vll, and 20 Q4 is an alkylene or alkylene-oxy group with 1 to 10 C atoms or a single bond, being different from Q'.

In case Q. in formula Vlil is an alkylene-oxy group, the O atom is preferably adjacent to the chiral C atom.

Further preferred are compounds with one or more groups P-Sp-X wherein Sp and/or X is a single bond.

In case of multiple occurrence of the group P. Sp and X, respectively, the 30 multiply occurring groups may be identical or different.

A further preferred embodiment of the present invention relates to multiblock compounds as described above and below, wherein at least one of the hydrocarbon blocks comprises one or more photoisomerisable 35 groups that isomerise, thereby changing their structure, upon photoradiation.

J - 27 Preferably the photoisomerisable group is a group A, X-A, X-A-X-AX or X4 A' (Z A2)m with A, X, A', A2, X' and m being as defined above.

5 Very preferably the photoisomerisable group is a cinnamate, stilbene, azobenzene or benzylidene phenyl amine group.

Especially preferred are the following compounds 1 o R':$ OR" IX-1 15 R' OR" IX-2

0 ON\\ OR" IX-3

R' OR" IX4

-, j,o R" IX-5 0 - Rot x-6 o R IX-7

- 28 R' 3 o R" IX-8 o O -'i' JAR" IX-9 o R'' IX-10 wherein R' and R" have one of the meanings of R given above, s is an 15 integer from 1 to 8, preferably 3, 4 or 5, and the phenyl rings can also be mono-, di-, tri- or tetrasubstituted by L as defined above.

As described above, the multiblock compounds according to the present invention can be designed to yield desired effects for specific applications.

20 From the formulae and definitions given above preferred structures are chosen according to the particular requirements of the material. Some examples of a strategy for molecular design are given below.

Planar alignment In order to achieve planar alignment at the air interface, the surfactant molecule preferably has an overall symmetrical structure. For example, in case of a simple C-B-C triblock, the hydrocarbon blocks C are preferably chosen to be either identical, or very similar in terms of size, shape and 30 polarity. Examples of this type are symmetrical compounds of formula V4 given above, in particular the following preferred compounds R' O 'O R" Vera

- 29 wherein s is an integer from 1 to 8, preferably 3, 4 or 5, and R' and R" have one of the meanings of R given above.

HomeotroPic alignment To obtain homeotropic alignment at the air interface, particularly suitable are triblock compounds wherein the hydrocarbon blocks are chosen to be very dissimilar, e.g. compounds of formula V-1 given above, in particular the following preferred compounds F F HO: R.t V-1 a wherein R" and s have the meanings given above.

Tilted alignment 20 Tilted alignment at the air interface can be achieved for example by selecting preferred structures that are intermediate between the compounds of formula V-1a and V - a above.

Control of adhesion 25 In addition to controlling the alignment at the air interface by use of multblock compounds according to the present invention, the adhesion of a subsequent coating can be optimised by selecting inventive multiblock compounds with structural elements that ensure good compatibility 30 between the two layers at the interface. For example, to get good adhesion of a subsequent layer of a very polar material (such as for example polyimide), the inventive compound preferably contains one or more polar terminal groups R. like for example a nitrile group, or terminal groups R groups that can participate in hydrogen bonding at the interface, 35 like for example hydroxyl, carboxyl, carbonyl, amino, nitro, amide or urethane groups.

- 30 The multiblock compounds according to the present invention can be synthesized according to or in analogy to methods which are known per se and which are described in standard works of organic chemistry such as, for example, Houben-Weyl, Methoden der organischen Chemie, 5 ThiemeVerlag, Stuttgart. Some specific methods of preparation can be taken from the examples.

Examples of suitable polymerisable mesogenic compounds that can be used as co-components in a polymerisable LC material according to the 10 present invention are disclosed for example in WO 93/22397; EP 0 261 712; DE 19504224; DE 4408171 and DE 4405316. The compounds disclosed in these documents, however, are to be regarded merely as examples that do not limit the scope of this invention.

15 Examples representing especially useful monoreactive chiral and achiral polymerisable mesogenic compounds are shown in the following list of compounds, which should, however, be taken only as illustrative and is in no way intended to restrict, but instead to explain the present invention: P-(CH2)xO COO Y (Xa) P-(CH2)XO COO MY

25 (Xb) L' P(CH2)xO COO OCO Y (Xc) P (CH2)xO COO RX (Xd) 35 P-(CH2)XO COO C:} Rx (Xe)

- 31 P-(CH2)XO Z Z :RX (Xf) P(CH2)X-O} vRX (Xg) 10 P-(CH2)xO CH=CH-COO RX (Xh) P(CH2)xo (COO)v RX (Xi) P-(cH2)xo coO CH2CH(CH3)C2H5 (Xk) 20 P(cH2)xo coo coo CH2cH(cH3)C2Hs (Xm) P-(CH2)xo COO-Ter (Xn) P-(CH2)xO COOChol (Xo) P-(CH2)XO COO-

(Xp) Examples of useful d i reactive chiral and ach iral polymerisab le mesogenic compounds are shown in the following list of compounds, which should, 35 however, be taken only as illustrative and is in no way intended to restrict, but instead to explain the present invention

- 32 L1 L2 P(CH2)xo COO OCO O(CH2)yP (Xq) L1 L2 P(CH2)x CH2CH2 CH2CH2 O(CH2)yP 10 L1 L2

P- o co26O2cko (Xs) 15 P(CH2)x CH=CHCO: _ OOCCH=CH o(CH2)yP (Xt) P(CH2) xO}Z,: H 3Z'{: O(CH2)yP In the above formulae, P is a polymerisable group, preferably an acryl, methacryl, vinyl, vinyloxy, propenyl ether, epoxy or styryl group, x and y are each independently 1 to 12, A is preferably 1,4-phenylene that is 30 optionally mono- di or trisubstituted by L' or 1,4-cyclohexylene, v is O or 1, Z is -COO-, -OCO-, -CH2CH2- or a single bond, Y is a polar group as defined for R above, Ter is a terpenoid radical like e.g. menthyl, Chol is a cholesteryl group, Rx is an non-polar alkyl or alkoxy group as defined for R above, and L' and L2 are each independently H. F. Cl, CN or an optionally 35 halogenated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkoxycarbonyloxy group with 1 to 7 C atoms.

- 33 The polymerisable material may also comprise one or more non polymerisable chiral dopants, which can also be mesogenic or liquid crystalline. Especially preferred are chiral dopants with a high twisting power comprising a chiral sorbitol, diphenylethandiol or 5 binapUthyl group with attached mesogenic groups. Especially preferred sorbitol dopants are disclosed in WO 98/00428, especially preferred diphenylethandiol dopants are described in GB 2,328,207.

Further preferred chiral dopants are chiral binapthyl derivatives as disclosed in EP 01111954.2, chiral binaphthol acetal derivatives as 10 described in WO 02/34739, chiral TADDOL derivatives as described in WO 02/06265, and chiral dopants having at least one fluorinated bridging group and a terminal or central chiral group as described in WO 02/06196 and WO 02/06195. Further suitable chiral compounds are e.g. the commercially available S 1011, R 811 or CB 15 (from 15 Merck KGaA, Darmstadt, Germany).

Anisotropic polymer films according to the present invention are prepared from a polymerisable liquid crystal material by aligning the material in its liquid crystal phase into macroscopically uniform orientation as described 20 above and polymerising or crosslinking it to fix the oriented state.

Polymerisation is preferably carried out by in-situ polymerization of a coated layer of the material. By using specific multiblock compounds as described above, the polymerisable liquid crystal materials are aligned in 25 their liquid crystal state into the desired orientation, e.g. homeotropic, planar or tilted, prior to polymerisation. The molecules are then polymerised or crosslinked to fix the uniform orientation of the liquid crystal state. Alignment and curing are carried out in the liquid crystal phase or mesophase of the material. This technique is known in the art 30 and is generally described for example in D.J. Broer, et al., Angew.

Makromol. Chem.183, (1990),45-66 In addition to the use of inventive multiblock compounds, it is possible to induce or improve a specific alignment of the liquid crystal molecules at 35 the substrate surface for example by treatment of the substrate, by shearing the material during or after coating, by application of a magnetic

$ - 34 or electric field to the coated material, or by the addition of further surface

active compounds to the liquid crystal material. Reviews of alignment techniques are given for example by 1. Sage in "Thermotropic Liquid Crystals", edited by G. W. Gray, John Wiley & Sons, 1987, pages 75-77, 5 and by T. Uchida and H. Seki in "Liquid Crystals - Applications and Uses Vol. 3", edited by B. Bahadur, World Scientific Publishing, Singapore 1992, pages 1-63. A review of alignment materials and techniques is given by J. Cognard, Mol. Cryst. Liq. Cryst. 78, Supplement 1 (1981), pages 1 77. Polymerisation takes place by exposure to heat or actinic radiation. Actinic radiation means irradiation with light, like 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 15 out by UV irradiation at a non-absorbing wavelength. As a source for actinic radiation for example a single UV lamp or a set of UV lamps can be used. When using a high lamp power the curing time can be reduced.

Another possible source for actinic radiation is a laser, like e.g. a UV laser, an IR laser or a visible laser.

Polymerisation is preferably carried out in the presence of an initiator absorbing at the wavelength of the actinic radiation. For example, when polymerising by means of UV light, a photoinitiator can be used that decomposes under UV irradiation to produce free radicals or ions that 25 start the polymerization reaction. When curing polymerisable materials with acrylate or methacrylate groups, preferably a radical photoinitiator is used, when curing polymerisable materials with vinyl, epoxide and oxetane groups, preferably a cationic photoinitiator is used. It is also possible to use a polymerization initiator that decomposes when heated to 30 produce free radicals or ions that start the polymerization. As a photoinitiator for radical polymerization for example the commercially available Irgacure 651, Irgacure 184, Darocure 1173 or Darocure 4205 (all from Ciba Geigy AG) can be used, whereas in case of cationic photopolymerisation the commercially available UVI 6974 (Union Carbide) 35 can be used.

- 35 The polymerisable material can additionally comprise one or more other suitable components such as, for example, catalysts, sensitizers, stabilizers, inhibitors, chain-transfer agents, co-reacting monomers, surface-active compounds, lubricating agents, wetting agents, dispersing agents, 5 hydrophobing agents, adhesive agents, flow improvers, defoaming agents, deaerators, diluents, reactive diluents, auxiliaries, colourants, dyes or pigments. In case of the preparation of patterned films, selected areas of the 10 polymerisable films are exposed to photoradiation to cure the material and thereby fix the alignment in these areas, for example by using a photomask.

This technique is known in prior art.

Without further elaboration, it is believed that one skilled in the art can, 15 using the preceding description, utilize the present invention to ist fullest

extent. The following examples are, therefore, to be construed as merely illustrative and not limitative of the remainder of the disclosure in any way

whatsoever. 20 In the foregoing and in the following examples, unless otherwise indicated, all temperatures are set forth uncorrected in degrees Celsius and all parts and percentages are by weight.

The following abbreviations are used to illustrate the liquid crystalline 25 phase behaviour of the compounds: K = crystalline; N = nematic; S = smectic; Ch = cholesteric; I = isotropic. The numbers between the symbols indicate the phase transition temperatures in C. ExamoIes Examole 1 PreDaration of triblock compounds Compound (1) was prepared according to the following reaction scheme.

- 36 4 + HOCH2(CF2)8CH2OH

OH OCH2(CF2)8CH2OH

(1) i: N,N'-dicyclohexylcarbodiimide, 4-(dimethylaminopyridine), THE, r.t.

To a stirred solution of benzoic acid (0.53g, 4.3mmol), 1 H,1 H,10H,1 OH-

perfluorodecane-1,10-diol (2.0g, 4.3mmol) and 4-(dimethylamino)pyridine 10 (56mg, 0.5mmol), in tetrahydrofuran (30mL), N,N'-dicyclohexyl carbodiimide (1.08g, 5.2mmol) was added. An immediate precipitate (1,3 dicyclohexylurea) formed and the reaction stirred at ambient temperature overnight, after which solid was removed by filtration, the liquor volume was increased with dichloromethane (30mL) and the organic layer was washed with water (2x1 OmL) and then dried (Na2SO4). Solvent was 15 removed under reduced pressure to give an oil (3.9g), which solidified on standing, and after column chromatography (silica: CH2CI2 as eluent) a white solid was isolated which was identified as benzoic acid 1,1,2,2,3,3, 4,4,5,5,6,6,7,7,8,8-hexadecafluoro-9-hydroxy-nonyl ester 20 (1.89, 73%, HPLC 99%), OH NMR (400MHz, CDCI3) 4.1 (2H, m), 4.8 (2H, t, 20Hz), 7.5 (2H Ar, t, 10Hz), 7.7 (1H Ar, t, 10Hz) and 8.1 (2H, d, 10Hz); 9F NMR (235MHz, CDCI3) -119.7 (2F, s), -122.4 (8F, s), -122.8 (2F, s), 123.7 (2F, s) and 124.0 (2F, s); El m/z 536 (-CH2OH), 105 (Ar-CO, 100%) and 77 (Ar).

25 Similarly the following materials were synthesised and identified using NMR and mass spectrometry: No. Structure 30 2 OCH2(CF2)6CH2OH

3 OCH2(CF2) 0CH2OH 1

- 37 4 - OCH2(cF2)8cH2OH 5 OCH2(CF2)8CH2OH

10 r j O OH 1 5 / OCH2(CF2)6CH2OH

20 8 OCH2(CF2)8CH2OH

_ - -} OCH2(CF2)8CH2OH

Example 2 - Preparation of symmetrical triblock compounds Compound (10) was prepared according to the following reaction scheme.

30 2 HO - <(CH2)7CH3 + HoCH2(CF2)8CH2OH O (CH2)9CH3 1 i

- 38 CH3(CH2)9, 40 O>__<(CH2)9CH3

CH3(CH2)7 OCH2(CF2)8CH2 0 (CH2)7CH3

(10) i: N,N'-dicyclohexylcarbodiimide, 4-(dimethylaminopyridine), THE, r. t.

To a stirred solution of 2-octyidodecanoic acid (2.76g, 8.8mmol), 1 H,1 H, 1 OH,1 OH-perfluorodecane-1,10-diol (2.0g, 4.3mmol) and 4 1 0 (dimethylamino)pyridine (120mg, 1.Ommol), in tetrahydrofuran (40mL), N,N'dicyclohexyicarbodiimide (2.1g, 10.1 mmol) was added. An immediate precipitate (1,3-dicyclohexylurea) formed and the reaction stirred at ambient temperature overnight, after which solid was removed by filtration, the liquor volume was increased with dichloromethane (40mL) and the 1 5 organic layer was washed with water (2x10mL) and then dried (Na2SO4).

Solvent was removed under reduced pressure to give an oil (3.09) and after column chromatography (silica; petrol 40-60:CH2CI2 1:1 as eluent - and iodine was-used-to develop TLC plates) a colourless liquid was isolated which was identified as 2-Octyl-dodecanoic acid 20 1,1,2,2 i 3,3, 4,4,5,5,6,6,7,7,8,8-hexadecafluoro-9-(2-octyl-dodecanoyloxy) nonyl ester (1.19, 24%, HPLC 99%), OH NMR (250MHz, CDCI3) 0.87 (12H, t, 5Hz),1.3 (56H, s),1.4-1.6 (OH, br m), 2.5 (2H, m) and 4.29 (4H, t, 15Hz); 19F NMR (235MHz, CDCI3) -119.0 (4F, s), -121.5 (8F, s), -122.8 (4F, s); El miz 1051 (M+).

Similarly the following materials were synthesised and identified using NMR and mass spectrometry: No Structure Phase T ransition 30 _ Temp. ( C) 11 > 0 0 < 22.7

OCH2(CF2)8CH2o 12 A

35 OcH2(cF2) cH2O

- 39 13 iOCH2(CF2)6CH2O: 5 14 >4OCH2(CF2)8CH2O:

15 >4OCH2(CF2)10CH2O:

10 O: Cot; 191.5 15 OCH2(CFz)8CH 1 20 18 - \ OCH2(cF-;ecH2O 70.0 25 OCH7(CF2)eCHzO 67. 0 20 n C3H7{ OCH2(CF2)8CH2O}n 2H7 137 0 21 n-C5H11{ j oCH2(CF2)8CH2O} n-C5H11 30 22 n C7H15 oCH2(CF2)8CH2O {}n-C7H1s 123. 9 23 6 CH2(CF2)8CH2O 150. 0

35 24 NC OCH2(CF2)8CH2O CN 140 2

- 40 25 NC ON

ocH2(cF2)8CH2o 136.7 5: OCH2(CF2)eCH2O CF3 10 Example 3 - Preparation of reactive symmetrical triblock compounds Compound (27) was prepared according to the following reaction scheme: 15 Cl lro(CH2)6 OH + HOCH2(CF2)8CH2OH 1''ii (CH2)6O O O(CH2)60

oCH2(CF2)8CH2)0 i, N,N'-dicyclohexylcarbodiimide, 4-(dimethylamino) pyridine, THF, r.t.

ii, Triethylamine, 35 C To a stirred solution of 4-[6-(3-Chloropropionyloxy)-hexyloxy] 30 benzoic acid (2.879, 8.7mmol), 1 H. 1 H. 1 OH, 1 OH-perfluorodecane 1,10-diol (2.1g, 4.6mmol) and 4-(dimethylamino) pyridine (150mg, 1.2mmol), in tetrahydrofuran (40mL), N,N'dicyclohexylcarbodiimide (2.09, 9.7mmol) was added. An immediate precipitate (1,3 dicyclohexylurea) formed and the reaction stirred at ambient 35 temperature overnight, after which solid was removed by filtration and triethylamine (7.5mL) was added. Stirring continued at 35 C for

-41 1 Oh and after cooling solid was filtered off, the liquid diluted with dichloromethane (40mL), washed with dilute hydrochloric acid (1 x 20mL) and then water (2 x 20mL) until neutral. The organic layer was then dried (Na2SO4) and after solvent removal a pale yellow solid 5 (4.39) was isolated. Column chromatography (dichloromethane as eluent) afforded a white solid (2.09,44%) which was identified as Di (4-(6-acryloyloxyhexyloxy)-benzoic acid) 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorodecyl ester (HPLC 96%), 'H NMR (250MHz, CDCI3) 0.83-1.88 (16H, overlapping m), 10 4.03 (4H, t, 6.3Hz), 4.18 (4H, t, 6.5Hz), 4.79 (4H, t, 13.6Hz), 5.78 6.43 (OH, m-acrylate resonances), 6.92 and 8.00 (8H, ABq, 8. 8Hz); OF NMR (235MHz, CDCI3)-122.0 (4F, s), -124.6 (8F, s), -126.0 (4F, s) ; El m/z 772 (M±238); Phase transition temperature = 76 C.

15 Similarly the following compound was synthesised and identified using NMR and mass spectroscopy: 20 O(CH2)3o ocu2(cF2)8cH2)o OtCH2) (28) Phase transition temperature = 54.7 C 25 ExamoIe 4 - Prena ration of asymmetric trib lock com oou nds Compound (29) was prepared according to the following reaction scheme.

30 O 'OCH2(CF2)8CH2OH

+ CH3(CH2)4 0H

- 42 (}(CH2)4CH3

OC H2(C F2)8C H2O

(29) i: N,N'-dicyclohexylcarbodiimide, 4-(dimethylaminopyridine), THE, r. t.

To a stirred solution of 4-(4-Pentyl-cyclohexyl)-benzoic acid (230mg, 0. 84mmol), compound (1) (490mg, 0.87mmol) and 4-(dimethylamino) 10 pyridine (24mg, 0.19mmol), in dichloromethane (30mL), N,N' dicyclohexylcarbodiimide (332mg, 1.61mmol) was added. An immediate precipitate (1,3-dicyclohexylurea) formed and the reaction stirred at ambient temperature overnight, after which solid was removed by filtration, the organic layer washed with water (2x10mL) and dried (Na2SO4).

15 Solvent was removed under reduced pressure to yield a white solid and after column chromatography (silica; CH2CI2 as eluent) a white solid was isolated and after recrystallization (petrol 40-601CH2CI2) this was identified as 4-(4-Pentyl-cyclohexyl)-benzoic acid 10-(benzoyl) 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-decyl ester (0.3g, 42%, 20 HPLC 98%), 'H NMR (250MHz, CDCI3) 0.9 (3H, t, 7Hz), 1.1 (2H, t, 10Hz), 1.15-1.55 (11H, brm),1.9 (4H, d,10Hz), 2.54 (1H, t, 10Hz), 4.81 (4H, overlapping t, 15Hz), 7.26-8.0 (9H Ar, m); '9F NMR (235MHz, CDCI3) 119.7 (4F, s), -122.3 (8F, s), -123.7 (4F, s); El m/z 822 (M+).

The following material was also synthesised and identified using NMR and mass spectroscopy: 9 o(CH2) 30 ocld2(cF2)8cH2)o 0 (3o) Example 5 Preparation of asymmetric compounds with increased polarity

e - 43 Following the procedure as described in example 4 compound (31) with a higher polarity was synthesised (71% yield, 98% purity by HPLC).

5 6740CH2(CF2)8CH2O s-

(31) Example 6 - Preparation of compounds with increased hvdrooen bonding canabilitv Using a procedure analogous to that described in example 2 the symmetric diamide (32) was formed from a fluorinated acid and an amine (HPLC purity 98%, m/z 752 (M+)): 2 CH3(CH2)4 NH2 +:(CF2)s: 1 i - (CF2)8:

25 CH3(CH2)4 N\ IN (CH2)4CH3

H (32) i: N,N'-dicyclohexylcarbodiimide, 4-(dimethylaminopyridine), THE, r.t.

Example 7 (Use Example) - Use of symmetrical triblock compound to promote planar alignment and improve wetting of subsequent layer 35 A first polymerisable nematic LC mixture (Mixture 1) was prepared as shown in Table 1, incorporating polymerisable mesogenic compounds A-D

- 44 (also referred to as reactive mesogens or "RM") and 0.6% of the state-of the-art non-ionic fluorocarbon surfactant FC171) (from 3M, St. Paul, Minnesota, USA) with the formula CnF2n+,So2N(C2H5)(CH2CH2o)xCH3, wherein n is an integer from 4 to 12 and x is an integer from 5 to 15. A 5 second polymerisable nematic LO mixture (Mixture 2) was prepared, consisting of essentially the same composition but omitting the surfactant.

A third polymerisable nematic mixture (Mixture 3) was also prepared with the same composition as Mixture 1, but replacing the surfactant FC171 by compound (14) of example 2.

Component Mixture 1 Mixture 2 Mixture 3 A 39.48 40.08 39.48

B 9.72 9.72 9.72

C 24.6 24.6 24.6

D 24.6 24.6 24.6

15 FC171 0.60 0.00 0.00

(14) 0.00 0.00 0.60

Irgacure 651 1.00 1.00 1.00 Table 1. Composition of polymerisable mixtures (weight percent solids).

20 CH3

CH2=CHCo2(CH2)6o43 COO OCO O(CH2)6O2CCH=CH2 (A) 25 CH2=CHCO2(CH2)3o H3 O(CH2)3O2CCH=CH2 (B) 30 CH2=CHCOo(CH2)6O <3coo ON (C) 35 CH2=CHCOO(CH2)6O COO OCH3

(D)

- 45 Irgacure 651<g) is a commercially available photoinitiator from Ciba AG (Baser, Switzerland).

5 A 50 weight percent solution of each of Mixtures 1-3 was prepared in xylene and the solution filtered through a 0.2 1lm PTFE membrane filter. Each solution was spin-coated onto a rubbed polyimide (JSR AL1054)/ glass substrate at 3,000 RPM for 30s. The resulting film was photo-polymerised using 19.5 mWcm 2 UV-A radiation for 60s in a nitrogen atmosphere. The 10 thickness of the films produced was determined to be approximately 3 Am from interference fringe measurements. In these films the rubbed polyimide acts to induce planar alignment of the RM molecules at the polyimide/RM interface, whereas the physical nature of the surfactants control the orientation of the RM molecules at the RM/air interface.

Contact angle measurements allow the determination of the film's overall surface energy and also allow this surface energy to be considered as a combination of dispersive and polar components. The surface energy of the films from Mixture 1-3 was determined from contact angle 20 measurements taken using a Kruss DSA10 instrument linked to a PC. The analysis was performed using the specialist software supplied with the instrument. Contact angles of water (BDH, HPLC grade) and dilodomethane (Aldrich 99%) were measured to determine the surface energy of the films. The solvents were used as supplied. All 25 measurements were taken at 20 C. The contact angles were determined from an average of at least 4 measurements fitted according to Young Laplace. The Surface energies were then obtained using Owen-Wendt Rabel-Kaelbe (OWRK) theory.

30 The quality and nature of the liquid crystal alignment of each film was determined by optical microscopy between crossed polarisers.The tilt angle of molecules (directors) in the annealed and non-annealed films were determined from measurements of the retardation of the LC films from -60 to + 60 . For the non-planar films, where appropriate, care was 35 taken to avoid the area immediately next to any reverse tilt defect RTD.

The retardation of the polymerised films was determined by measuring the

- 46 transrnission of the film between parallel polarisers, with the orientation axis of the film at an angle of 45 to the polariser axis. The optical transmission was measured with an Oriel Spectrograph, for the wavelength range of 420-800nm, using a tungsten lamp as the light 5 source. The retardation of the film was calculated by fitting the observed intensity measurements to theory. The tilt angle profile of the nematic director throughout the polymerised film was calculated by measuring the retardation of the film (as described above) as a function of the angle of incidence of the light beam when the sample is rotated from 0 to + 60 10 (See O.Parri et al., Mol.Cryst.Liq.Cryst., Vol 332, p273, 1999). Hence the tilt angle at the air 43RMpair and substrate RWsub interfaces were obtained. In each case the tilt angle at the substrate interface was 1 .

A second layer was then coated onto each film, using the same mixture 15 mixture composition as the first layer, and examined for signs of de wetting. The surface energies, alignment, tilt angle at the air surface and wetting behaviour of these films, are given in Table 2.

Mixture Surface energy y/mNm 1 d/mNm 1 P/mNm ' 1 33.40 28.48 4.92

25 2 48.96 31) sat 4.56 Table 2: Surface energies of RM films fabricated from the mixtures detailed in Table 1. The superscripts d and p refer to the dispersive and 30 polar contributions to the surface energies, respectively.

The retardation profiles (optical retardation versus viewing angle) used to determine the tilt profile for Mixtures 1, 2 and 3 are shown in Figure 1, 2 and 3, respectively.

* - 47 As can be seen from Table 2, the surface energy of the film containing FC171 (Mixture 1) is much lower than a film produced from essentially the same mixture without FC171 (Mixture 2). To ensure good wetting of a second layer, the coating liquid must have a lower surface energy than the 5 substrate. Hence, it is difficult for other hydrocarbon materials coated on the polymerised layer of Mixture 1, to wet a surface of Mixture 1, and thus the second layer is observed to de-wet. In contrast, the second layer will wet a film of Mixture 2. However the film of Mixture 2 does not show perfect uniform orientation and contains some tilt defects, having an 10 average tilt angle at the air interface Corsair = 77 . In contrast, the film containing Compound 14 (Mixture 3), has a surface energy close to that for Mixture 2 so that the second layer does not show de-wetting, and promotes planar alignment producing an average tilt angle at the air interface (3RWair = 1.0 which is similarto the value of Corsair = 1.8 obtained 15 by Mixture 1.

The above results show that the addition of small amounts of a fluorocarbon surfactant known from prior art can be used to promote

planar oriented, open cast, liquid crystal films, as described in WO 20 99145082. This can produce planar alignment, however, the accumulation of the fluorocarbon surfactant at the liquid crystal/air interface causes a concomitant decrease in the surface energy of the liquid crystal film causing subsequent layers to dewet from the liquid crystal film.

25 The above results further show that this problem can be solved by using a triblock compound (14) of formula 1-1 with a = 0, wherein B is a surface active fluorocarbon chain that is capped by two identical hydrocarbon chains so that the compound is symmetrical. When incorporating such a compound into a polymerisable LC mixture a planar film is obtained. The 30 fluorocarbon chain as the most surface-active component will preferentially migrate to the LC/air interface, whereas the two hydrocarbon chains are chemically and hence physically identical and thus have an equal tendency to migrate to the LC/air interface. In this way the surfactant tends to lie parallel to the substrate at the LCJair interface and 35 hence promote planar orientation. The incorporation of the hydrocarbon chains into the surfactant increases the surface energy of the films,

- 48 compared to those containing the prior art surfactant, enabling these films

to be wetted by other layers.

It is also possible to modify the above described example, e.g. by using a 5 triblock compound of formula 1-1 wherein the hydrocarbon parts of the molecule are not equivalent, to obtain alignment other than planar, for example homeotropic or tilted.

The preceding examples can be repeated with similar success by 10 substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.

From the foregoing description, one skilled in the art can easily ascertain

15 the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

Claims (1)

1. Claims 1. A compound having a multiblock structure, comprising at least

   one first block comprising an aliphatic, alicyclic, aromatic or araliphatic 5 hydrocarbon group (hydrocarbon block) and at least one second block comprising a fluorocarbon, siloxane or oligo-or poly(oxaalkylene) group, wherein said compound comprises at least two hydrocarbon blocks and/or at least one hydrocarbon block comprising a cyclic group.

   to 2. A compound as claimed in claim 1, characterized in that it is a nonionic compound.

   3. A compound as claimed in claim 1 or 2, comprising 3 to 5 hydrocarbon blocks and 1 to 4 blocks comprising a fluorocarbon, siloxane 15 or oligoor poly(oxaalkylene) group.

   4. A compound as claimed in any one of claims 1 to 3, selected of formula l: 20 Cn((B C2)a B C')n l wherein B is a bivalent block comprising a fluorocarbon, siloxane or 2S oligo- or poly(oxaalkylene) group.

   C, is in case independently of one another a monovalent hydrocarbon block, or, in case one or more of C2, C" or the other groups C, contain a cyclic group, may also denote H. C2 is in case independently of one another a bivalent hydrocarbon block,

   -ED On is an n-valent hydrocarbon block, n Is an integer from 1 to 6, and a isO, 1,2,30r4.

   5. A compound as claimed in claim 4, selected from the following formulae C1 B (C2 B)a C1 1-1 1 2 - 3 n r 1 C -B-(C -B)b-w t=-,2 1-' 15 C4(B-C1)4 13

   wherein B. C', c2 and a have the meaning of Formula I, C3 is a trivalent hydrocarbon block, C4 is a tetravalent hydrocarbon block, and b is O or 1.

   5 6. A compound as claimed in any of claims 1 to 5, wherein the blocks comprising a fluorocarbon, siloxane or oligo- or poly(oxaalkylene) group are selected from the following formulae

   -st Q-(CF2)c Q 11-1 \ - 5 Q \> - Q

   , F F T-O (CH2CH20)e (CH2CH2CH2O)rT 11-3 Y-(SiR1R2-O)g SiR1R2 y 11= wherein 1S Q iS-CH2o- -oCH2- -CH2S- -SCH2- -CH2-o-Co-NRo-, -N R -CO-O-C H2-, -CH2-O-CO-O-, -O-CO-OCH2-, -CO-O-,

   -O-CO-, -CO-S-, -S-CO-, -CO-NR - or-NR -CO-, T is -CO-, -CO-O-, -O-CO-, CO-NR - or-NR -CO-, 20 y is-CH20-, -OCH2- or-CH2CH2-, R is H or alkyl with 1 to 12 C-atoms, R' and R2 are independently of each other H or an aliphatic, 25 alicyclic, aromatic or araliphatic group with 1 to 10 C atoms, c is an integer from 2 to 20, d is an integer from 1 to 4, e and f are independently of each other an integer from O to 25,with e f = 2to 30, and 9 is an integer from 1 to 10.

   -so 7. A compound as claimed in claim 6, wherein the blocks comprising a fluorocarbon, siloxane or oligo- or poly(oxaalkylene) group are selected from the following formulae -OCH2-(CF2)c-CH20- 11-1 a -COO-(CF2)C-OCO- 111 b -NH-COO-(CF2)C-OCO-NH- 11-1 c -OCO-(CF2)C-COO- 11-1d -NH-CO-(CF2)c-CONH- 11-1e --CH20-(CH2CH2O)e-CH2 11-3a -CH20-(CH2CH2CH20)e CH2 11-3b -COO(CH2CH20)e-CO- 11-3c -COO-(CH2CH2CH20)e-CO- 11-3d -NH-COO-(CH2CH2O)e-CONH- 11-3e -NH-COO-(CH2CH2CH2O)e-CO-NH- 11-3f -CH2-O-(Si(CH3)2-O)g-Si(CH3) 2-O-CH2- 114a -CH2- C H2-o-(si(cH3)2-o)g-si(cH3)2-o-cH2-cH2- 114b

   -53 wherein c is 8, 9 or 10, e is an integer from 3 to 14, and 9 is an integer from 1 to 10.

   8. A compound as claimed in any one of claims 1 to 7, wherein the 5 hydrocarbon blocks are selected from H. straight-chain or branched alkyl, or comprise up to four of each of the sub-units Sp, X, A and R which may be connected in a linear or branched manner, wherein Sp is an n-valent spacer group or a single bond, X is-O-,-S-,-CO-,-COO-,-OCO-,-CO-S-,-S-CO-, -O-COO-, -CO-NR -, -NR -CO-, -OCH2-, -CH20-,

   -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-,

   15 -C H2C H2-, -C F2C H2-, -C H2C F2-, -C F2 C F2-, -C H = N-,

   -N=CH-, -N=N-, -CH=CH-, -CF=CH-, -CH=CF-,

   20 -CF=CF-, -C=C-, CH=CH-COO-, -OCO-CH- or a single bond, A is an nvalent 5- or 6-membered aromatic or carbocyclic group which may also contain one or more hetero atoms, may be connected to neighboured groups in any of the 1-, 2-, 3-, 4-, 5- or 6-position, and may be 25 substituted by one or more groups L or P-Sp-X, L is halogen or a cyano, nitro, alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group with 1 to 7 C atoms, wherein one or more H atoms may be substituted by F or Cl,

   -54 R is H. F. Cl, Br, I, CN,SCN,SF5H, NO2, or n-valent straight chain, branched or cyclic alkyl with 1 to 20 C atoms, which may be unsubstituted, mono- or poly substituted by F. Cl, Br, I or ON, it being also possible for one or more non-adjacent CH2 groups to be replaced, in each case independently from one another, by -O-, -S-, -NH-, -NR -, -SiR R -, -CO-, -COO-, -OCO -OCO-O-,-S-CO-,-CO-S-,-CH=CH- or-C_C- in such a manner that O and/or S atoms are not linked directly to one another, or denotes P-Sp- X, P is a polymerisable group, R and R are independently of each other H or alkyl with 1 to 12 C-atoms, and 5 n is an integer from 2 to 6.

   9. A compound as claimed in claim 8, wherein at least one of the hydrocarbon blocks comprises a group of formula lil S p-X'-A' (Z A2)m R wherein, 25 X' is-O-,-S-,-OCH2-,-CH20-,-CO-,-COO-,-OCO-, -CO-S-,-S-CO-,OCO-O-,-CO-NR -,-NR -CO-,

   -OCH2-,-CH2O-,-SCH2-,-CH2S-,-CH=CH-COO-,

   -OOC-CH=CH- or a single bond, A, and A2 independently of each other have one of the meanings 30 of A,

   -55 Z is-O-,-S-,-CO-,-COO-,-OCO-,-CO-S-,-S-CO-, -O-COO-, -CO-N R -, -N R CO-, -OCH2-, -CH?O-, -SCH2-,

   5 -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH2CH2-,

   -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-,

   -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C-C-,

   -CH=CH-COO-, -OCO-CH=CH- or a single bond, m isO, 1, 20r3, and Sp, X, R. R , R , P. L and have the meanings of claim 7.

   10. A compound as claimed in claim 8 or 9, wherein at least one of the 15 hydrocarbon blocks comprises a group selected from the following formulae A-R 1111

   A1-A2-R 1112

   A,-OCO-A2-R 1113

   20 A1-COO-A2-R 1114

   A,-O-A2-R 1115

   A'-CH20-A2-R 1116

   A1-OCH2-A2-R 1117

   A1-CH2CH2-A2-R 1118

   A'-A2A2R 1119

   25 A'-OCO A2 A2 R 11110

   A'-COO A2 A2 R 1111 1

   A,-COO-A2-CH2CH2-A2-R 11112

   Ai-OCO-A2-CH2CH2-A2-R 11113 A'-CH2CH2-A2-COO-A2-R 11114

   30 A,-CH2CH2-A2-OCO-A2-R 11115

   A1-COO-A2 coo-A2-R 11116 A'-COO-A2-OCO-A2-R 11117

   -5& A' -OCO-A2-OCO A2 R 1111 8

   A'-CH2CH2-A2-CH2CH2-A2-R 11119

   /(CH2)h-H CH IV (CH2)j-H wherein At, A2, R have the meanings given in claim 11 and 12, and h and i are identical or different integers from O to 20.

   11. A compound as claimed in any of claims 8 to 10, wherein A, A, and A2 are selected from phenyl in which, in addition, one or more CH groups may be replaced by N. cyclopentane or cyclohexane in which, in addition, one or two non-adjacent CH2 groups may be replaced by O and/or S. 5 thiophene, thiazole, thiadiazole, dioxolane, cyclohexene, piperidine, indane, benzofuran, benzo[bithiophene, benzooxazole, benzothiazole, naphthalene, decahydronaphthalene, tetrahydronaphthalene, it being possible for all these groups to be unsubstituted, mono- or polysubstituted with L as defined in claim 8.

   12. A compound as claimed in any of claims 1 to 11, selected from the following formulae R-A'-(Z-A2)m-X'-Q-(CF2)C-Q-H V-1 F F R-A'-(Z-A2)m-X1-Q Q-H V-2 F F

   -57 (CH2)h-H\ /(CH2)h-H 7C Q-(cF2)c-Q C\ V-3 s (CH2)j-H (CH2)i-H R-A1-(ZA2)m-X1-Q-(CF2)c-Q-X1-(A2-Z)m-A1-R V4 10 R-A1-(Z-A2)m-X1-Q Q-X1-(A2-Z)mA1-R V-5 F F wherein R. A1, A2, Z. X', Q. c, d, h, i and m have the meanings given in claims 4 to 11.

   f5 do 13. A compound as claimed in any of claims 1 to 12, wherein at least one of the hydrocarbon blocks comprises one or more photoisomerisable groups that isomerise, thereby changing their structure, upon photoradiation. 75 14. A compound as claimed in claim 13, wherein the photoisomerisable group is a group A, X-A, X-A-X-A-X or X,-A'-(Z-A2)m with A, X, A', A2, X, and m being as defined in claims 8 and 9.

   15. A compound as claimed in claim 14, wherein the photoisomerisable so group is a cinnamate, stilbene, azobenzene or benzylidene phenyl amine group.

   -5s 16. A compound substantially as hereinbefore described with reference to Examples 1 to 6.

   17. Use of a compound as claimed in any of claims 1 to 16 as 5 surfactant, aligning, adhesion promotion or wetting agent in liquid crystal materials. 18. Use of a compound as claimed in any of claims 1 to 16 in a layer of liquid crystal material provided on a substrate, to promote alignment of the to liquid crystal material at the substrate or at the open surface, and/or to promote adhesion between the liquid crystal material and the substrate or between the liquid crystal material and subsequent liquid crystal layers, andlor to promote wetting of the substrate.

   |5 19. Use of a compound substantially as hereinbefore described with reference to Example 7.

   20. A method to control in a liquid crystal material provided on a substrate the alignment of the liquid crystal molecules at the substrate 20 andJor at the open surface, by adding one or more compounds according to at least one of claims 1 to 16 to the liquid crystal material.

   21. A method as claimed in claim 20, wherein the alignment is parallel, homeotrophic, tilted, splayed, twisted or bent alignment.

   22. A liquid crystal material comprising one or more mesogenic or liquid crystal compounds and at least one compound as claimed in any claims 1 to 16.

   Jo 23. A liquid crystal material as claimed in claim 22, comprising at least one polymerisable compound, which can be one of said compounds of

   -5) claims 1 to 16, said mesogenic or liquid crystal compounds or an additional compound.

   24. A liquid crystal material as claimed in claim 23, comprising at least 5 one compound as claimed in any claims 13 to 15 with a photoisomerisable group that undergoes isomerisation, thereby changing its structure, upon photoradiation, wherein the different isomeric structures of the compound promote different alignment directions in the liquid crystal material.

   to 25. An anisotropic polymer film obtained by providing a layer of polymerisable liquid crystal material as claimed in any of claims 22 to 24 on a substrate and polymerising-the material that is aligned in its liquid crystal phase, wherein the alignment of the liquid crystal molecules at the substrate and/or at the open surface is controlled by appropriate selection 15 of the compounds as claimed in any of claims 1 to 16.

   26. A multilayer anisotropic polymer film comprising two or more polymerised layers prepared as claimed in claim 25, wherein second and higher numbered layers, in the sequence of their preparation, are to prepared on the first or previous layers serving as a substrate, and wherein the alignment in the second and higher layers and/or the adhesion between adjacent layers is controlled by appropriate selection of the compounds as claimed in any claims 1 to 16 that are present in the layers. 27. A multilayer film as claimed in claim 26, wherein a first alignment is induced in a first of said two or more polymerised layers, and a second alignment different from said first alignment is induced in a second of said two or more polymerized layers adjacent to said first layer, by adding at so least one multiblock compound as claimed in any claims 1 to 16 to the polymerisable LO material of said first layer before polymerization.

   28. A patterned anisotropic polymer film comprising a polymerized liquid crystal material with uniform alignment, having a pattern of at least two areas of different alignment direction, obtained by - providing a layer of a polymerisable liquid crystal material as 5 claimed in claim 24 comprising at least one photoisomerisable compound on a substrate.

   - exposing selected areas of the layer to photoradiation that induces isomerisation in the photoisomerisable compound, thereby changing the alignment direction of the liquid crystal to material in the exposed areas, and - polymerising the selected areas and/or the entire layer to fix the alignment.

   29. A polymer film substantially as hereinbefore described with 15 reference to and as shown in Figures 1 to 3.

   30. A liquid crystal material provided on a substrate that is covered by an anisotropic polymer film as claimed in any of claims 25 to 28, or provided on an anisotropic polymer film as claimed in any of claims 25 to to 28 serving as substrate, wherein the liquid crystal material is optionally a material as claimed in any claims 22 to 24, and wherein the alignment of the liquid crystal molecules at the substrate and/or at the open surface, and/or the adhesion between the liquid crystal material and the anisotropic polymer film are controlled by appropriate selection of the compounds as 25 claimed in any claims 1 to 16 that are present in the anisotropic polymer film and/or in the liquid crystal material.

   31. Use of a liquid crystal material or polymer film as claimed in any of claims 22 to 30, in active or passive optical devices like liquid crystal JO displays, polarisers, compensators, colour filters, alignment layers, beam splitters, birefringent, coloured or patterned films for use in optical, decorative and security applications, security markings, holographic

   images, hot stamping foils and for the preparation of liquid crystal pigments, further as oriented films with charge transport or semiconductor properties in optical or electronic devices, like field transistors as

   components of integrated circuitry, thin film transistors in flat panel display s applications or for REID (Radio Frequency Identification) tags, semiconducting components for OLED (organic light emitting diode) applications, electroluminescent display devices, backlights, photovoltaic or sensor devices, electrode materials in batteries, photoconductors and electrophotographic applications.