Claims
- 1. An optical element comprising at least one substrate, an optical alignment layer on a surface of the substrate and a liquid crystal layer on a surface of the optical alignment layer, wherein the optical alignment layer comprises anisotropically absorbing molecules consisting essentially of at least one diaryl ketone and is exposed to polarized light sufficient to align the liquid crystal layer.
- 2. In an optical element of claim 1 in the configuration of a liquid crystal display element comprising two substantially parallel substrates having facing surfaces, an alignment layer disposed on each facing surface wherein at least one of the alignment layers is an optical alignment layer, wherein each optical alignment layer comprises anisotropically absorbing molecules; a liquid crystal layer at least partly aligned and disposed between, and adjacent to, the alignment layers, and a spacer separating the alignment layers; the improvement wherein the anisotropically absorbing molecules consist essentially of at least one diaryl ketone and wherein the liquid display element is substantially free from irregularities in the alignment pattern when viewed at 100 time magnification between crossed polarizers.
- 3. An optical element of claim 1 in the configuration of an optical storage medium comprising a plurality of substrates, each coated with an optical alignment layer on at least one surface, the coated substrates being separated by a liquid crystal layer.
- 4. An optical element of claim 1 wherein the diaryl ketone consists essentially of at least one copolyimide of at least one diaryl ketone tetracarboxylic dianhydride and at least three diamines, consisting essentially of at least three structural elements of the formula IIa. wherein Y is a divalent radical selected form the formulas IIIa and IVa wherein Z and Z1 are selected, independently, from the group consisting of —S—, —SO2—, —O—, — CH2CH2—, —CH2—, —NR—, —C(CF3)2—, —C(O)— and a covalent bond, wherein R is a C1-C4 hydrocarbon chain; X2 is independently selected from —R3, —OR3, —SR3, —N(R4)R3; wherein R3 is selected from C1-C3 perfluorinated alkyl chain and partially fluorinated alkyl chain and R4 is independently selected from R3 and H; X3 is independently selected from X2 and H; X is independently selected from the group consisting of H, Cl, F, and Br; and m is 1 or 0.
- 5. An optical element of claim 1 wherein the diaryl ketone consists essentially of at least one copolyimide of at least one diaryl ketone tetracarboxylic dianhydride and at least two diamines, consisting essentially of at least one structural element of the formula IIa wherein Y is a divalent radical selected from the formulas IIIa and IVa and at least one structural element of formula VII wherein Z and Z1 are selected, independently, from the group consisting of —S—, —SO2—, —O—, — CH2CH2—, —CH2—, —NR—, —C(CF3)2—, —C(O)— and a covalent bond, wherein R is a C1-C4 hydrocarbon chain; X2 is independently selected from —R3, —OR3, —SR3, —N(R4)R3; wherein R3 is selected from C1-C3 perfluorinated alkyl chain and partially fluorinated alkyl chain and R4 is independently selected from R3 and H; X3 is independently selected from X2 and H; X is independently selected from the group consisting of H, Cl, F, and Br; and m is 1 or 0; and the copolyimide consists of about from 99 to 1 mol % of at least one structural element of formula IIa and about from 1 to 99% of at least one structural element of formula VII.
- 6. An optical element of claim 1 wherein the diaryl ketone consists essentially of at least one copolyimide of at least one diaryl ketone tetracarboxylic dianhydride, at least one alicyclic tetracarboxylic dianhydride and at least one diamine, consisting essentially of at least two structural elements of the formula IIa and Va wherein Y is a divalent radical selected from the formula IIIa and IVa wherein Z and Z1 are independently selected from the group consisting of —S—, —SO2—, —O—, — CH2CH2—, —CH2—, —NR—, —C(CF3)2—, —C(O)— and a covalent bond, wherein R is a C1-C4 hydrocarbon chain; X2 is independently selected from —R3, —OR3, —SR3, —N(R4)R3; wherein R3 is selected from C1-C3 perfluorinated alkyl chain and partially fluorinated alkyl chain and R4 is independently selected from R3 and H; X3 is independently selected from X2 and H; X is independently selected from the group consisting of H, Cl, F, and Br; and m is 1 or 0; P is a tetravalent radical derived from said alicyclic tetracarboxylic dianhydride; and the copolyimide comprises 95 to 20 mol % of at least one structural element of formula IIa and 5 to 80 mol % of at least one structural element of formula Va.
- 7. An optical element of claim 1 wherein the diaryl ketone consists essentially of at least one polyimide polymer consisting essentially of at least one structural element of the formula VIII. wherein P is a tetravalent optical derived from said alicyclic tetracarboxylic dianhydride; and X is independently selected from the group consisting of H, Cl, F, and Br.
Parent Case Info
This application is a division of application Ser. No. 08/886,560, filed Jul. 1, 1997, now U.S. Pat. No. 5,965,691 which is a division of application Ser. No. 08/624,945, filed Mar. 29, 1996, now U.S. Pat. No. 5,807,498.
Government Interests
This invention was made with United States Government support under cooperative agreement No. 70NANB4H1525 awarded by the United States Department of Commerce. The United States Government has certain rights in the invention.
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