Reversibly crosslinked orientable liquid crystalline polymers

An anisotropic liquid crystalline (LC) polymer film comprising:

• a) 70-99.8 wt. % of a reversibly crosslinkable LC poly(meth)acrylate wherein said poly(meth)acrylate comprises
• i) 85-99.9 mol % of monomer units of formula III:
• ##STR29## where R.sub.6 is hydrogen or methyl;
• D is --COO-- or --CONR1"--, where R1" is H or a C.sub.1-4 alkyl group;
• E is a spacer unit with 1-14 chain members;
• and
• M is a mesogenic group;
• and
• ii) 0.1-15 mol% of monomers of formula I ##STR30## where U is O, S, or NH;
• R.sub.1 is hydrogen or methyl;
• and
• R.sub.2 is --X--R.sub.3,
• where
• X is --(CH.sub.2).sub.n -- or --(O--CH.sub.2).sub.n --, and n=an integer from 1 to 6, and R.sub.3 is formula Ia:
• ##STR31## were V.sub.1 =CH;
• R', R", R"', and R"" each independently is hydrogen or an n-alkyl having 1-6 C atoms;
• and
• V.sub.1 '=O, S, or CH.sub.2 ;
• or R.sub.3 represents formula Ib:
• ##STR32## where A=N or CH;
• J.sub.1 represents N or CH;
• R.sub.4 ', R.sub.5 ', R.sub.6 ', and R.sub.7 ' each independently is hydrogen, CN, or halogen;
• J.sub.1 ' represents O, S, NH, or CH.sub.2 ;
• A" represents C;
• and
• R.sub.1 ', R.sub.2 ', and R.sub.3 ' each independently is hydrogen, CN, halogen, carboxyl, or a carboxylate ester;
• and
• b) 0.2-30 wt. % of a compound selected from the group consisting of the compounds of formulas IIa-IIf below:
• ##STR33## where B.sub.1 is CH;
• B.sub.1 ' represents CH.sub.2, O, or S;
• R.sub.9, R.sub.10, R.sub.11, and R.sub.12 each independently is hydrogen or an n-alkyl group with 1-6 C atoms;
• and
• Z is a C.sub.4-30 aliphatic, or C.sub.4-30 aromatic group, which also may contain additional hetero atoms or hetero atom groups;
• and ##STR34## where G represents N or CH;
• G' represents NH, O, S, or CH.sub.2 ;
• Q represents N or CH;
• R.sub.4 and R.sub.5 each independently is hydrogen, CN, or halogen;
• and
• Z' is a C.sub.4-30 aliphatic or C.sub.4-30 aromatic group, which also may contain additional hetero atoms or hetero atom groups.