| 摘要 |
Aromatic polyimides containing trifluoromethyl groups resulting from the reaction, under imidation conditions, of 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]bis-(1,3-isobenzof urandione) with at least one polyamine of general formula <IMAGE> in which each of the R groups independently represents a linear or branched alkyl group having from 1 to 16 carbon atoms and each of the a values independently is 0 or an integer from 1 to 4. These polyimides are preferably obtained by formation, in a first stage, of a polyamide/acid which is, in a second stage, subjected to imidation/polycondensation conditions, preferably by progressive heating or by heating in stages, preferably in the presence of at least two polar organic solvents, preferably with azeotropic removal of the water of reaction. Use of the polyimide in the preparation of alignment layers for liquid crystal displays, of coatings for levelling and/or protecting an electronic device, and of light waveguides.
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