Polymerisable LC material and polymer film with negative optical dispersion

1. Polymerisable LC material comprising from 1 to 45% of one or more compounds of formula I

wherein

U 1,2 are independently of each other selected from

including their mirror images, wherein the rings U 1 and U 2 are each bonded to the central bitolane group via the axial bond, and one or two non-adjacent CH 2 groups in these rings are optionally replaced by O and/or S, and the rings U 1 and U 2 are optionally substituted by one or more groups L,

Q 1,2 are independently of each other CH or SiH,

Q 3 is C or Si,

A 1-4 are independently of each other selected from non-aromatic carbocylic or heterocyclic groups and aromatic or heteroaromatic groups, which are optionally substituted by one or more groups R 5 , and wherein each of -(A 1 -Z 1 ) m —U 1 —(Z 2 -A 2 ) n - and -(A 3 -Z 3 ) o —U 2 —(Z 4 -A 4 ) p - does not contain more aromatic groups than non-aromatic groups,

Z 1-4 are independently of each other —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR 0 —, —NR 0 —CO—, —NR 0 —CO—NR 0 —, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CF 2 O—, —OCF 2 —, —CF 2 S—, —SCF 2 —, —CH 2 CH 2 —, —(CH 2 ) 3 —, —(CH 2 ) 4 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —CF 2 CF 2 —, —CH═CH—, —CY 1 ═CY 2 —, —CH═N—, —N═CH—, —N═N—, —CH═CR 0 —, —C≡C—, —CH═CH—COO—, —OCO—CH═CH—, CR 0 R 00 or a single bond,

Y 1,2 are independently of each other H, F, Cl, CN or R 0 ,

R 0 and R 00 are independently of each other H or alkyl with 1 to 12 C-atoms,

m and n are independently of each other 0, 1, 2, 3 or 4,

o and p are independently of each other 0, 1, 2, 3 or 4,

R 1-5 are independently of each other identical or different groups selected from H, halogen, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(═O)NR 0 R 00 , —C(═O)X 0 , —C(═O)R 0 , —NH 2 , —NR 0 R 00 , —SH, —SR 0 , —SO 3 H, —SO 2 R 0 , —OH, —NO 2 , —CF 3 , —SF 5 , P-Sp-, optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 40 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, or denote P or P-Sp-, or are substituted by P or P-Sp-, wherein the compounds comprise at least one group R 1-4 that denotes P or P-Sp- or is substituted by P or P-Sp-,

P is a polymerisable group,

Sp is a spacer group or a single bond, and further comprising from 50% to 99% of polymerisable mesogenic or liquid crystalline compounds different from formula I.

2. Polymerisable LC material according to claim 1 , characterized in that U 1 and U 2 in formula I are selected from

wherein R 5 is as defined for the compound of formula I.

3. Polymerisable LC material according to claim 1 , characterized in that A 1-4 in formula I are selected from trans-1,4-cyclohexylene and 1,4-phenylene that is optionally substituted with one or more groups L as defined for the compound of formula I.

4. Polymerisable LC material according to claim 1 , characterized in that the mesogenic groups do not comprise more than one unsaturated or aromatic ring.

5. Polymerisable LC material according to claim 1 , characterized in that Z 1-4 in formula I are selected from —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR 0 —, —NR 0 —CO—, —NR 0 —CO—NR 0 —, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CF 2 O—, —OCF 2 —, —CF 2 S—, —SCF 2 —, —CH 2 CH 2 —, —(CH 2 ) 3 —, —(CH 2 ) 4 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —CF 2 CF 2 —, —CH═CH—, —CY 1 ═CY 2 —, —CH═N—, —N═CH—, —N═N—, —CH═CR 0 —, —C≡C—, —CH═CH—COO—, —OCO—CH═CH—, CR 0 R 00 or a single bond, wherein R 0 , R 00 , Y 1 and Y 2 have the meanings given for the compound of formula I.

6. Polymerisable LC material according to claim 1 , characterized in that P in formula I is selected from CH 2 ═CW 1 —COO—, CH 2 ═CW 1 —CO—

CH 2 ═CW 2 —(O) k1 —, CH 3 —CH═CH—O—, (CH 2 ═CH) 2 CH—OCO—, (CH 2 ═CH—CH 2 ) 2 CH—OCO—, (CH 2 ═CH) 2 CH—O—, (CH 2 ═CH—CH 2 ) 2 N—, (CH 2 ═CH—CH 2 ) 2 N—CO—, HO—CW 2 W 3 —, HS—CW 2 W 3 —, HW 2 N—, HO—CW 2 W 3 —NH—, CH 2 ═CW 1 —CO—NH—, CH 2 ═CH—(COO) k1 -Phe-(O) k2 —, CH 2 ═CH—(CO) k1 -Phe-(O) k2 —, Phe-CH═CH—, HOOC—, OCN—, and W 4 W 5 W 6 Si—, with W 1 being H, F, Cl, CN, CF 3 , phenyl or alkyl with 1 to 5 C-atoms, in particular H, Cl or CH 3 , W 2 and W 3 being independently of each other H or alkyl with 1 to 5 C-atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 being independently of each other Cl, oxaalkyl or oxacarbonylalkyl with 1 to 5 C-atoms, W 7 and W 8 being independently of each other H, Cl or alkyl with 1 to 5 C-atoms, Phe being 1,4-phenylene that is optionally substituted, and k 1 and k 2 being independently of each other 0 or 1.

7. Polymerisable LC material according to claim 1 , characterized in that Sp in formula I is selected of formula Sp′-X′, such that P-Sp- is P-Sp′-X′—, wherein

Sp′ is alkylene with 1 to 20 C atoms, preferably 1 to 12 C-atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH 2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR 0 —, —SiR 0 R 00 —, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —NR 0 —CO—O—, —O—CO—NR 0 —, —NR 0 —CO—NR 0 —, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,

X′ is —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR 0 —, —NR 0 —CO—, —NR 0 —CO—NR 0 —, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CF 2 O—, —OCF 2 —, —CF 2 S—, —SCF 2 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —CF 2 CF 2 —, —CH═N—, —N═CH—, —N═N—, —CH═CR 0 —, —CY 1 ═CY 2 —, —c≡C—, —CH═CH—COO—, —OCO—CH═CH— or a single bond,

and R 0 , R 00 , Y 1 and Y 2 have the meanings given for the compound of formula I.

8. Polymerisable LC material according to claim 1 , characterized in that the compounds of formula I are selected from the following subformulae

wherein R 1-5 , A 1-4 , Z 1-4 , m, n, o and p have the meanings given for the compound of formula I, and B denotes

9. Polymerisable LC material according to claim 1 , characterized in that the compounds of formula I are selected from the following subformulae

wherein B is

Z has one of the meanings of Z 1 given for the compound of formula I, R has one of the meanings of R 1 given for the compound of formula I that is different from P-Sp-, P, Sp, L and r are as defined for the compound of formula I, and the benzene rings are optionally substituted by one or more groups L as defined for the compound of formula I.

10. Polymer film being obtained by polymerising a polymerisable LC material according to claim 1 .

11. Polymer film according to claim 10 , characterized in that it is a +A plate or +C plate.

12. Polymer film according to claim 10 , characterized in that it is a +A plate and has a retardation dispersion >0.7 and <0.98 at 0° angle of incidence.

13. Polymer film according to claim 10 , characterized in that it is a +C plate and has a retardation dispersion >0.65 and <0.95 at 60° angle of incidence.

14. Polymerisable LC material according to claim 1 or polymer film obtained by polymerising said polymerisable LC material, characterized in that it has a negative retardation dispersion.

15. Polymerisable LC material according to claim 1 or polymer film obtained by polymerising said polymerisable LC material, characterized in that it has a birefringence≧0.05 and <0.15 at 550 nm.

16. Polymerisable LC material according to claim 1 , or polymer film obtained by polymerising said polymerisable LC material, characterized in that it has a birefringence≧0.035 and <0.1 at 550 nm.

17. Optical, electronic or electrooptical device, or a component thereof, comprising a polymerisable LC material according claim 1 , or a polymer film obtained by polymerising said polymerisable LC material.

18. Component according to claim 17 , characterized in that it comprises one or more optically uniaxial films selected from an A-plate, C-plate, negative C-plate or O-plate, a twisted optical retarder, a twisted quarter wave foil (QWF), an optically biaxial film, an achromatic retarder, an achromatic QWF or half wave foil (HWF), a film having a cholesteric, smectic, nematic or blue phase, a film having homeotropic, splayed, tilted, planar or blue-phase alignment, which is uniformly oriented or exhibits a pattern of different orientations.

19. Component according to claim 17 , characterized in that it is an optical compensator for viewing angle enhancement, a brightness enhancement element, or an achromatic retarder.

20. Component according to claim 17 , characterized in that it is a retarding component in an optoelectronic device requiring similar phase shift at multiple wavelengths, including combined CD/DVD/HD-DVD/Blu-Ray, reading and/or writing and/or re-writing data storage systems, an achromatic retarder for optical devices including cameras, or an achromatic retarder for displays including OLED and LCD's.

21. Device or component according to claim 17 , characterized in that is selected from electrooptical displays, LCDs, optical films, polarisers, compensators, beam splitters, reflective films, alignment layers, colour filters, holographic elements, hot stamping foils, coloured images, decorative or security markings, LC pigments, adhesives, non-linear optic (NLO) devices, optical information storage devices, electronic devices, organic semiconductors, organic field effect transistors (OFET), integrated circuits (IC), thin film transistors (TFT), Radio Frequency Identification (RFID) tags, organic light emitting diodes (OLED), organic light emitting transistors (OLET), electroluminescent displays, organic photovoltaic (OPV) devices, organic solar cells (O-SC), organic laser diodes (O-laser), organic integrated circuits (O-IC), lighting devices, sensor devices, electrode materials, photoconductors, photodetectors, electrophotographic recording devices, capacitors, charge injection layers, Schottky diodes, planarising layers, antistatic films, conducting substrates, conducting patterns, photoconductors, electrophotographic applications, electrophotographic recording, organic memory devices, biosensors, biochips, optoelectronic devices requiring similar phase shift at multiple wavelengths, combined CD/DVD/HD-DVD/Blu-Rays, reading, writing re-writing data storage systems, or cameras.