| 摘要 |
The invention concerns cholesteric phase-forming polymers, a process for their preparation and their use. Cholesteric phase-forming polymers and oligomers according to the invention substantially comprise as molecular units: A. at least one duofunctional chiral molecular unit comprising at least one cyclic structural element which is different from the monosubstituted p-phenylene group; B. at least one duofunctional achiral or racemic molecular unit which comprises at least one cyclic structural element containing at least four ring members; and C. at least one duofunctional molecular unit which can optionally be chiral or achiral and cyclic or acyclic and is different from the molecular units A and B actually used. The molecular units are connected by ester groups with (C=O)= and O-C=O, carbonic ester with O-(C=O)-O, amide groups CONH, N-substituted amide CONR, cyclic imide with six ring members, azomethines CH=N and CR=N. The groups R, which may be identical or different, can be C1-C22 alkyl, aryl, aralkyl and the non-cyclic portion can be linear or branched if the group is non-cyclic or if a combination with a non-cyclic group is present, and linear, branched and/or cyclic groups can optionally comprise at least one heteroatom which is different from C and H, and/or can optionally be substituted or even heteroatom-substituted. The substituent can in particular also carry one or a plurality of halogens, provided that the molecular unit A is not derived exclusively from camphoric acid. The polymers and oligomers according to the invention are obtained by replacing between 0.01 and 50 mol percent of one or a plurality of the monomers corresponding to the molecular units B and/or C by monomers producing the chiral units A according to the invention in the prescription formula of any (nematic) liquid crystal polymer (LCP). The cholesteric phase-forming polymers and oligomers according to the invention are suitable as moulding compound granulates for further processing in known shaping processes, e.g. injection moulding. They can also be processed to form pigments for iridescent paints. |
