Photoalignment composition

Abstract

The present invention relates to a photoalignment composition comprising a) 0.001 to 20%, by weight, preferably, 1 to 10% by weight, more preferably 1 to 9% by weight of at least one photoreactive compound (I) that comprises a photoalignment group and b) 80 to 99.999% by weight, preferably, 90 to 99% by weight, more preferably 91 to 99% by weight of at least one compound (II) that does not comprise a photoalignment group, and c) optionally at least one reactive or non reactive additives, and d) optionally at least one solvent. Further the present invention relates to the use of this photoalignment composition for the alignment of liquid crystals or liquid crystal polymers, in electrooptical and optical elements, systems and devices.

Claims

1. A photoalignment composition comprising a) 0.001 to 20%, by weight, of at least one photoreactive compound (I) that comprises a photoalignment group, which is of formula: ##STR00017## whereby the aromatic rings are unsubstituted or substituted and wherein the compound residue (Ia) ##STR00018## represents a straight-chain or branched C.sub.1-C.sub.16fluoralkyl group, wherein F is fluorine, and x is an integer from 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9; B represents a straight-chain or branched C.sub.1-C.sub.16alkyl group, which is in addition to its fluorine substituent(s) unsubstituted or substituted by di-(C.sub.1-C.sub.16alkyl)amino, C.sub.1-C.sub.6alkoxy, nitro, cyano and/or chlorine; and wherein one or more CH.sub.2 group may independently from each other be replaced by a linking group, wherein the linking group is selected from O, CO, COO, OCO, ##STR00019## NR.sup.1, NR.sup.1CO, CONR.sup.1, NR.sup.1COO, OCONR.sup.1, NR.sup.1CONR.sup.1, CHCH, CC, OCOO, and Si(CH.sub.3).sub.2OSi(CH.sub.3).sub.2, and wherein: R.sup.1 represents a hydrogen atom or C.sub.1-C.sub.6alkyl; and b) 80 to 99.999% by weight, of at least one compound (II) that does not comprise a photoalignment group, wherein the at least one compound (II) is polyamic acid and/or polyimide, and c) optionally at least one reactive or non reactive additives, and d) optionally at least one solvent.

2. A photoalignment material comprising a composition as claimed in claim 1.

3. A method of using the photoalignment material as claimed in claim 2, comprising providing the photoalignment material as an structured or unstructured photalignment layer, for aligning organic or inorganic compounds, wherein the photoalignment material is prepared by a process comprising a) applying the photoalignment composition, wherein said composition has the same meaning and preferences as given above; and then b) optionally drying, and then c) irradiating the applied photoalignment composition, obtained after step a) or step b), with aligning light to induce the anisotropy.

4. A photoalignment composition as claimed in claim 1, wherein the at least one photoreactive compound (I) is present in an amount of 0.1 to 2% by weight and the at least one compound (II) is present in an amount of 98 to 99.9% by weight.

5. A photoalignment composition comprising a) 0.001 to 20%, by weight, of at least one photoreactive compound (I) that comprises a photoalignment group, which is of formula: ##STR00020## whereby the aromatic rings are unsubstituted or substituted and wherein the compound residue (Ia) ##STR00021## represents a straight-chain or branched C.sub.1-C.sub.16fluoralkyl group, wherein F is fluorine, and x is an integer from 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9; B represents a straightchain or branched C.sub.1-C.sub.16alkyl group, which is in addition to its fluorine substituent(s) unsubstituted or substituted by di-(C.sub.1-C.sub.16alkyl)amino, C.sub.1-C.sub.6alkoxy, nitro, cyano and/or chlorine; and wherein one or more CH.sub.2 group may independently from each other be replaced by a linking group, wherein the linking group is selected from O, CO, COO, OCO, ##STR00022## NR.sup.1, NR.sup.1CO, CONR.sup.1, NR.sup.1COO, OCONR.sup.1, NR.sup.1CONR.sup.1, CHCH, CC, OCOO, and Si(CH.sub.3).sub.2OSi(CH.sub.3).sub.2, and wherein: R.sup.1 represents a hydrogen atom or C.sub.1-C.sub.6alkyl; and b) 80 to 99.999% by weight, of at least one compound (II) that does not comprise a photoalignment group, wherein the at least one compound (II) is selected from the group consisting of polymers and copolymers, and c) optionally at least one reactive or non reactive additives, and d) at least one solvent.

6. A photoalignment composition as claimed in claim 5, wherein the at least one compound (II) is selected from the group consisting of poly-acrylate, -methacrylate, -imide, -amic acid, -amide, -ethylene, -ethyleneoxide, -propylene, -vinyl chloride, -ethylene terephthalate, -styrene, -carbonate, -lactic acid, -urethane, -ester, -ether, and -silicon.

7. A photoalignment composition as claimed in claim 5, wherein the at least one photoreactive compound (I) is present in an amount of 0.1 to 2% by weight and the at least one compound (II) is present in an amount of 98 to 99.9% by weight.

8. A photoalignment composition as claimed in claim 1, wherein the at least one photoreactive compound (I) that comprises a photoalignment group, which is of formula: ##STR00023## whereby the aromatic rings are unsubstituted or substituted and wherein the compound residue (Ia) ##STR00024## represents a straight-chain or branched C.sub.1-C.sub.16fluoralkyl group, wherein F is fluorine, and x is an integer from 0 or 3, 4, 5 or 7; B represents a straight-chain or branched, substituted or unsubstituted C.sub.1-C.sub.8alkyl, wherein one or more the CH.sub.2 group may be replaced by a group selected from O, CO, COO, OCO, and CHCH, with the proviso that oxygen atoms are not directly linked to each other.

9. A photoalignment composition as claimed in claim 1, wherein the at least one photoreactive compound (I) that comprises a photoalignment group, which is of formula: ##STR00025## whereby the aromatic rings are unsubstituted or substituted and wherein the compound residue (Ia) ##STR00026## represents a straight-chain or branched C.sub.1-C.sub.16fluoralkyl group, wherein F is fluorine, and x is an integer from 0; B represents a straight-chain or branched, substituted or unsubstituted C.sub.1-C.sub.8alkyl, wherein one or more the CH.sub.2 group may be replaced by a group selected from O, CO, COO, OCO, and CHCH, with the proviso that oxygen atoms are not directly linked to each other.

10. A photoalignment composition as claimed in claim 1, wherein the at least one photoreactive compound (I) that comprises a photoalignment group, which is of formula: ##STR00027## whereby the aromatic rings are unsubstituted or substituted and wherein the compound residue (Ia) ##STR00028## represents a straight-chain or branched C.sub.1-C.sub.16fluoralkyl group, wherein F is fluorine, and x is an integer from 3, 4, 5 or 7; B represents a straight-chain or branched, substituted or unsubstituted C.sub.1-C.sub.8alkyl, wherein one or more the CH.sub.2 group may be replaced by a group selected from O, CO, COO, OCO, and CHCH, with the proviso that oxygen atoms are not directly linked to each other.

11. A photoalignment composition as claimed in claim 1, comprising at least one reactive or nonreactive additive in an amount of 1 to 10% by weight, and d) optionally at least one solvent.

12. A photoalignment composition as claimed in claim 1, comprising at least one reactive or nonreactive additive, which is a a stabilizer in an amount of 0.1 to 1% by weight, and d) optionally at least one solvent.

13. A photoalignment composition as claimed in claim 1, comprising at least one solvent, wherein said composition disposed in said solvent is between 1 and 50% by weight in said solvent(s).

14. A photoalignment composition as claimed in claim 1, wherein the at least one photoreactive compound (I) that comprises a photoalignment group, which is of formula: ##STR00029## whereby the aromatic rings are unsubstituted or substituted and wherein the compound residue (Ia) ##STR00030## represents a straight-chain or branched C.sub.1-C.sub.16fluoralkyl group, wherein F is fluorine, and x is an integer from 3, 4, 5 or 7; B represents a straight-chain or branched, substituted or unsubstituted C.sub.1-C.sub.8alkyl, wherein one or more the CH.sub.2 group may be replaced by a group selected from O, CO, COO, OCO, and CHCH, with the proviso that oxygen atoms are not directly linked to each other.

Description

EXAMPLES

Definitions Used in the Examples

(1) ##STR00007##
prepared as described in WO07/071,091 examples 9 and 18 (polyamic acid 18 and polyimide 18)

(2) ##STR00008##

(3) Polymer 2 is prepared in analogy to methods known in the art such as for example Polymerisation step: Formation of the polyamic acid

(4) 6 g (30.26 mmol) of 4,4-diaminodiphenyl derivative (4,4-diaminodiphenyl methane, 4,4-diaminodiphenyl thioether, 4,4-diaminodiphenyl ether, 4,4-diaminodiphenyl glutaric ester) was solubilised in 71 mL of 1-methyl-2-pyrrolidone (NMP). The mixture was cooled to 0 C. for 10 minutes. 6.648 g (29.66 mmol) of 2,3,5-tricarboxycyclopentylacetic-1,2:3,4-dianhydride were added to the solution. The mixture was stirred at 0 C. for two hours and then at rt for 3 hours. The reaction gave the polyamic acid precursor having a viscosity of 0.4 dL/g.

(5) ##STR00009##
prepared as described in WO07/071,091 examples 9 and 18 (polyamic acid 18 and polyimide 18)

(6) ##STR00010##

(7) Prepared as described in analogy to U.S. Pat. No. 6,632,909

(8) ##STR00011##

(9) Prepared as described in analogy to WO96/10049

(10) ##STR00012##

(11) Prepared as described in analogy to U.S. Pat. No. 6,107,427

(12) Liquid crystal polymer 1: Composition A in anisol (1:20)

(13) Composition A: the composition comprises, LCP1 (see below given structure), LCP 2 (see below given structure), Tinuvin 123 (manufactured by Ciba Specialty Chemicals), Irgacure 369 (manufactured by Ciba Speciality Chemicals), butyl-hydroxy-toluol having the following ratios (78.43:18.63:0.98:0.98:0.98)

(14) ##STR00013##

(15) Prepared as described in WO00/39631

(16) ##STR00014##

(17) Prepared as described in U.S. Pat. No. 6,676,851

Example 1

(18) A liquid crystal cell was prepared wherein the liquid crystal was aligned by photo reactive polymer 1.

(19) A 4% solution of polymer 1 was prepared by mixing the solid polymer 1 in the solvent n-methyl-2-pyrrolidone(NMP) and stirred thoroughly till the solid polymer 1 is dissolved and a second solvent butyl cellulose(BC) is added and the whole composition is stirred thoroughly to obtain final solution. The solvent ratio between n-methyl-2-pyrrolidone and butyl cellulose is 1:1.

(20) The above polymer solution was spin-coated onto the two ITO coated glass substrates at a spin speed of 1600 rpm for 30 seconds.

(21) After spin coating the substrates were subjected to baking procedure consisting of pre-baking for 5 minutes at 130 C. and post-baking for 40 minutes at a temperature of 200 C. The resulting layer thickness was around 60 nm.

(22) The substrates with the coated polymer layer on top were exposed to linearly polarized UV light(LPUV) at an incidence angle of 40 relative to the normal of the substrate surface. The plane of polarization was within the plane spanned by the substrate normal and the propagation direction of the light. The applied exposure dose was 48 mJ/cm.sup.2.

(23) After LPUV exposure a cell was assembled with the 2 substrates, the exposed polymer layers facing to the inside of the cell. The substrates were adjusted relative to each other such that the induced alignment directions were parallel to each other (corresponds to the anti-parallel rubbed configuration in case of alignment by rubbing procedure). The cell was capillary filled with liquid crystal MLC6610(Merck KGA), which had a negative dielectric anisotropy.

(24) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 87.7 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 2

(25) Another cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution to be coated comprised of polymer 2 instead of polymer 1 and the spin speed used was 2100 rpm for 30 seconds.

(26) Between crossed polarizers the cell appeared bright, independent of the angle between the polarizers and the edges of the substrates of the cell.

(27) Consequently, the liquid crystals were not aligned in vertical direction and there was no preferred azimuthal orientation direction. Because of the missing orientation, a tilt angle could not be determined. However, from the bright appearance of the cell it was concluded that the liquid crystal molecules were oriented almost planar. This interpretation fits with the fact that polymer 2 is a commercial material used as an orientation layer for liquid crystals in twisted nematic LCDs, where typically tilt angles of a few degrees are required.

Example 3

(28) Polymer 1 and polymer 2 were mixed in ratio of 20:80 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(29) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 20:80 per weight % and the spin speed used was 1900 rpm for 30 seconds.

(30) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 87.7 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 4

(31) Polymer 1 and polymer 2 were mixed in ratio of 10:90 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(32) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 10:90 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(33) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 87.6 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 5

(34) Polymer 1 and polymer 2 were mixed in ratio of 5:95 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(35) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 5:95 per weight % and the spin speed used was 2050 rpm for 30 seconds.

(36) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 87.9 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 6

(37) Polymer 1 and polymer 2 were mixed in ratio of 4:96 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(38) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 4:96 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(39) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 87.5 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 7

(40) Polymer 1 and polymer 2 were mixed in ratio of 3:97 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(41) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 3:97 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(42) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 87.7 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 8

(43) Polymer 1 and polymer 2 were mixed in ratio of 2:98 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(44) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 2:98 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(45) A tilt angle of 0.04 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 9

(46) Polymer 1 and polymer 2 were mixed in ratio of 1:99 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(47) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 1:99 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(48) A tilt angle of 0.02 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 10

(49) Polymer 1 and polymer 2 were mixed in ratio of 0.5:99.5 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(50) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 0.5:99.5 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(51) A tilt angle of 0.02 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 11

(52) Polymer 1 and polymer 2 were mixed in ratio of 0.2:99.8 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(53) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 0.2:99.8 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(54) A tilt angle of 0.02 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 12

(55) Polymer 1 and polymer 2 were mixed in ratio of 0.1:99.9 per weight % to form a blend composition. A 4% solution was prepared as per the procedure explained in Example 1 except that the two polymers were mixed in the solvent at the same time.

(56) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 and polymer 2 in ratio of 0.1:99.9 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(57) A tilt angle of 0.02 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 13

(58) A cell was prepared with the same processing and exposure conditions as in Example 1, except that solution used comprises of polymer solution A which is a commercial material OPTMER AL60702(JSR corporation) used as an orientation layer for liquid crystals in vertically aligned LCDs, where high tilt angles are required, and also except that the spin speed used was 3000 rpm for 30 seconds

(59) The liquid crystals were oriented in vertical direction. A tilt angle of 90 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers, but there was no preferred azimuthal orientation direction.

(60) This material was used in blend composition for further Examples 14, 15, 16 and 17 by replacing the polymer 2 of blend compositions listed in Examples 7, 8, 9 and 10.

Example 14

(61) A blend composition in ratio of 3:97 per weight % was prepared using polymer 1 listed in Example 1 and polymer solution A listed in Example 13 as per the procedure explained in Example 1 except that the solvents used were n-methyl-2-pyrrolidone, butyl cellulose and gamma butyrolactone in ratio of 3:3:4.

(62) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 listed in Example 1 and polymer solution A listed in Example 13 in ratio of 3:97 per weight % and the spin speed used was 2700 rpm for 30 seconds.

(63) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 88.0 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 15

(64) A blend composition in ratio of 2:98 per weight % was prepared using polymer 1 listed in Example 1 and polymer solution A listed in Example 13 as per the procedure explained in Example 1 except that the solvents used were n-methyl-2-pyrrolidone, butyl cellulose and gamma butyrolactone in ratio of 3:3:4.

(65) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 listed in Example 1 and polymer solution A listed in Example 13 in ratio of 2:98 per weight % and the spin speed used was 2700 rpm for 30 seconds.

(66) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 88.5 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 16

(67) A blend composition in ratio of 1:99 per weight % was prepared using polymer 1 listed in Example 1 and polymer solution A listed in Example 13 as per the procedure explained in Example 1 except that the solvents used were n-methyl-2-pyrrolidone, butyl cellulose and gamma butyrolactone in ratio of 3:3:4.

(68) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 listed in Example 1 and polymer solution A listed in Example 13 in ratio of 1:99 per weight % and the spin speed used was 2700 rpm for 30 seconds.

(69) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 89.4 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 17

(70) A blend composition in ratio of 0.5:99.5 per weight % was prepared using polymer 1 listed in Example 1 and polymer solution A listed in Example 13 as per the procedure explained in Example 1 except that the solvents used were n-methyl-2-pyrrolidone, butyl cellulose and gamma butyrolactone in ratio of 3:3:4.

(71) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 1 listed in Example 1 and polymer solution A listed in Example 13 in ratio of 0.5:99.5 per weight % and the spin speed used was 2700 rpm for 30 seconds.

(72) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 89.8 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 18

(73) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the polymer 3 was used instead of polymer 1 and the spin speed used was 2000 rpm for 30 seconds.

(74) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 88.7 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 19

(75) An experiment was performed with similar combination as in Example 10, except that the polymer 1 is replaced by polymer 3 listed in Example 18.

(76) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 3 and polymer 2 in ratio of 0.5:99.5 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(77) A tilt angle of 0.02 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 20

(78) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the polymer 4 was used instead of polymer 1 and the spin speed used was 2000 rpm for 30 seconds.

(79) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 89.2 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 21

(80) An experiment was performed with similar combination as in Example 10, except that the polymer 1 is replaced by polymer 4 listed in Example 20.

(81) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 4 and polymer 2 in ratio of 0.5:99.5 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(82) A tilt angle of 0.04 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 22

(83) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the polymer 5 was used instead of polymer 1 and the spin speed used was 1300 rpm for 30 seconds.

(84) The liquid crystal in the cell showed well defined homeotropic orientation. A tilt angle of 89.9 was measured using the crystal rotation method. Upon applying a voltage of 5V to the electrodes of the cell, the liquid crystal molecules switched from the vertical orientation to a planar orientation, which was observed by arranging the cell between crossed polarizers. The azimuthal orientation direction of the switched liquid crystals was determined to lie in the polarization plane of the LPUV light used for photo-exposure.

Example 23

(85) An experiment was performed with similar combination as in Example 6, except that the polymer 1 is replaced by polymer 5 listed in Example 22.

(86) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 5 and polymer 2 in ratio of 4:96 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(87) A tilt angle of 28 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 24

(88) An experiment was performed with similar combination as in Example 9, except that the polymer 1 is replaced by polymer 5 listed in Example 22.

(89) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 5 and polymer 2 in ratio of 1:99 per weight % and the spin speed used was 2000 rpm for 30 seconds.

(90) A tilt angle of 0.09 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 25

(91) An experiment was performed with similar combination as in Example 5, except that the polymer 1 is replaced by polymer 6.

(92) A cell was prepared with the same processing and exposure conditions as in Example 1, except that the solution used is a blend composition of polymer 6 and polymer 2 in ratio of 5:95 per weight % and the spin speed used was 1800 rpm for 30 seconds.

(93) A tilt angle of 0.2 was measured using the crystal rotation method. The cell was arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 45 to the axis of crossed polarizers, and the cell has bright appearance which concludes that the liquid crystal molecules were oriented almost planar. The cell was again arranged between crossed polarizers without any voltage applied, with the director of liquid crystal in the cell set at 0 to any one of the transmission axis of the polarizers, the cell has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal lying in the polarization plane of the LPUV light used for photo exposure.

Example 26

(94) From Examples 1 to 25, the anisotropic orientation of liquid crystal in cells were observed. Another experiment was performed where the anisotropic orientation of liquid crystal polymer was observed.

(95) Blend composition listed in Example 11 was used for this experiment. A glass substrate was processed with this above blend composition similar to the processing steps in Example 1, except that only one substrate is used for processing and no liquid crystal is used. This coated substrate was subjected to a second process step by spin coating with liquid crystal polymer 1 at a spin speed of 1200 rpm for a duration of 60 seconds which gives thickness of around 700 nm, then the coated substrate is placed in atmosphere of nitrogen and cross linked with the help of UV A light source at energy dose of 240 mJ/cm.sup.2.

(96) The above substrate was arranged between crossed polarizers, with the director of liquid crystal polymer set at 45 to the axis of crossed polarizers, and the substrate has bright appearance which concludes that the liquid crystal polymer molecules were oriented almost planar. The substrate was again arranged between crossed polarizers, with the director of liquid crystal polymer set at 0 to any one of the transmission axis of the polarizers, the substrate has dark appearance, which concludes the well defined azimuthal orientation direction of liquid crystal polymer lying in the polarization plane of the LPUV light used for photo exposure.

Example 27

(97) Similar experiment was performed as in Example 25, except that the blend composition listed in Example 12 was used.

(98) Similar observations of orientation as in Example 25 was concluded.

Example 28

(99) A blend 1 was prepared that consisted of 95% by weight of a compound (II) as given in the below table, and 5% by weight of a photoreactive compound (II) as given in the table below. Blend 1 was dissolved to 2% by weight in cyclopentanone and stirred for half an hour at room temperature.

(100) Indium tin oxide (ITO) coated glass plates were used as substrates. By means of spin-coating a solution of blend 1 with a solid content of 2 weight percent in cyclopentanone an alignment layer with a dry thickness of approximately 60 nm was prepared with the spin parameters of 2000 rpm during 60 s. The alignment layer was subsequently thermally treated on a hot-plate for 10 minutes at a temperature of 180 C. After that, the photo-alignment layer was vertically exposed to linearly polarised UVB light (wavelengths between 280 and 320 nm). A dose of 150 mJ/cm.sup.2 was applied at an intensity of 3 mW/cm.sup.2. In a next step, a 25 weight percent solution in cyclopentanone of the formulation M1 (Example 1) was spin-coated on top of the functionalized photo-alignment layer with the spin parameters of 800 rpm during 60 s. A dry film thickness of approximately 800 nm was achieved this way. A thermal treatment at a temperature of 40 C. on a hot-plate was then carried out for a duration of 10 minutes.

(101) ##STR00015## ##STR00016##

(102) Compounds (II) are prepared in analogy to methods known in the art such as for example Polymerisation step: Formation of the polyamic acid

(103) (30.26 mmol) of 4,4-diaminodiphenyl derivative (4,4-diaminodiphenyl methane, 4,4-diaminodiphenyl thioether, 4,4-diaminodiphenyl ether, 4,4-diaminodiphenyl glutaric ester) was solubilised in 71 mL of 1-methyl-2-pyrrolidone (NMP). The mixture was cooled to 0 C. for 10 minutes. (29.66 mmol) of 1,2,3,4-cyclobutanetretracarboxilic acid dianhydride were added to the solution. The mixture was stirred at 0 C. for two hours and then at rt for 3 hours. The reaction gave the polyamic acid precursor having a viscosity of 0.4 dL/g.