Liquid crystalline copolymer
AssigneeBASF SE
InventorsKarl-Heinz Etzbach, Bernd Hisgen
Life of this patent
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Abstract
A liquid crystalline copolymer contains a comonomer to which a radical ##STR1## is bonded, where X is a chemical bond, O or NR.sup.1, Y is a chemical bond or --CO--, R.sup.1 is hydrogen or C.sub.1 -C.sub.4 -alkyl and A is a linear or branched C.sub.2 -C.sub.20 -alkylene group which may be interrupted by --O-- or ##STR2## The liquid crystalline copolymers have very good lightfastness, high dichroism and a high absorption.
Claims11
A liquid crystalline copolymer which contains, as copolymerized units, a comonomer of the formula:
- ##STR39## where X is a chemical bond, --O-- or ##STR40## wherein R.sup.1 is hydrogen or C.sub.1 -C.sub.4 -alkyl, Y is a chemical bond or --CO--, A is a linear or branched C.sub.2 -C.sub.20 -alkylene group where the carbon chain of the alkylene group can be interrupted by --O-- or ##STR41## R.sup.2 is hydrogen, methyl or chlorine and R.sup.3 is a mesogenic group of the formula:
- ##STR42## in which Y.sup.1 is --O--, ##STR43## or --S--, Z is a chemical bond or a radical of the formula ##STR44## --CH.dbd.CH--, --N.dbd.N, ##STR45## --N.dbd.CH-- or --CH.dbd.N--, U is a chemical bond or radical of the formula:
- ##STR46## R.sup.5 is hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.5 -C.sub.7 -cycloalkyl, C.sub.1 -C.sub.12 -alkoxy, C.sub.4 -C.sub.12 -alkoxycarbonyl, C.sub.1 -C.sub.12 -alkanoyloxy, fluorine, chlorine, bromine, cyano, phenyl, 4-cyanophenyl or nitro, R.sup.6 is hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.1 -C.sub.12 -alkoxy or C.sub.1 -C.sub.12 -alkoxycarbonyl and R.sup.7 is methyl, ethyl, methoxy, ethoxy or chlorine.
A liquid crystalline copolymer which is of the formula ##STR49## where R.sup.2 is hydrogen or methyl, X is --O-- Y is a chemical bond, A is a linear C.sub.2 -C.sub.20 -alkylene group, R.sup.3 is ##STR50## R.sup.5 is C.sub.1 -C.sub.12 -alkyl, C.sub.1 -C.sub.12 -alkoxy, C.sub.4 -C.sub.12 -alkoxycarbonyl, C.sub.1 -C.sub.12 -alkanoyloxy, fluorine, chlorine, cyano, phenyl, 4-cyanophenyl or nitro and R.sup.6 is C.sub.1 -C.sub.12 -alkyl, the copolymer containing from 0.5 to 40% by weight, based on the polymer, of a dye containing radical.
Dependencies are inferred from the claim text.