Liquid crystalline copolymer

A liquid crystalline polymer obtained by in-situ photopolymerization of at least one polymerizable reactive liquid crystal compound selected from

• a) compounds of formula Ia, ##STR50## wherein ##STR51## with W being H, Cl or alkyl with 1-5 C atoms P is alkylene with up to 12 C atoms, it being possible for one or more non adjacent CH.sub.2 groups to be replaced by --O--,
• X is --O--, --S--, --COO--, --OCO, --C.tbd.C-- or a single bond,
• R.sup.2 is an achiral alkyl radical with up to 15 C atoms, it being possible for one or more CH.sub.2 groups to be replaced by --O--, --S--, --CO--, OCO--, COO--, --O--CO--O-- in such a manner that oxygen atoms are not linked directly to one another, or alternatively R.sup.2 has one of the meanings given for R.sup.1 -P-X-,
• Z.sup.2 is --CH.sub.2 CH.sub.2 -- or a single bond, ##STR52## it being possible for these rings to be substituted by CN or halogen, ##STR53## b) compounds of formula Ib, ##STR54## wherein R.sup.1, R.sup.2, P, and X have the meaning given, L.sub.o is fluorine or chlorine,
• Z.sup.2 is --CH.sub.2 CH.sub.2 -- or a single bond, or in the case that L.sub.o is Cl, Z.sup.2 denotes also --O--CO--, ##STR55## denotes a 4, 4-biphenyldiyl group being optionally substituted by a fluorine or chlorine atoms (L.sub.o), and p is 0 or an integer between 1 and 4,
• c) compounds of formula IIa ##STR56## wherein R.sup.1, P, X and p have the meaning given, Z.sup.4 is --CH.sub.2 CH.sub.2 -- or a single bond,
• Q is --CF.sub.2, --OCF.sub.2, --C.sub.2 F.sub.4 or --OC.sub.2 F.sub.4 or a single bond, if Y.sup.1 is F or Cl,
• Y.sup.1 is H, F, or Cl
• d) compounds of formula IIb ##STR57## wherein R.sup.1, P, X, Q, Y.sup.1 and p have the meaning given, and q and r are each independently 0 or an integer selected from 1 to 4 and wherein R.sup.2 cannot be a chiral group.