| 摘要 |
The invention relates to a process for producing a dielectric polyurethane polymer through reaction of a mixture comprising: a) a compound which contains isocyanate groups and has a number-average isocyanate functionality of <u>></u> 2.3 and <u>< </u>6; b} a compound which contains isocyanate-reactive groups and has a number-average functionality of isocyanate-reactive groups of <u>> </u>1.5 and <u><</u> 6; c) a polymeric additive obtainable through stoichiometric reaction of c1) a monoisocyanate of the general formula 1a and / or 1b NCO-X-(A)n (formula 1a) NCS-X-(A)n (formula 1b) with c2) a polyol component with a number-average molecular weight Mn of from 100 to 1500 g/mol and a functionality of from 2 to 4; d) optionally a catalyst; where X is an organic moiety having a delocalized electron system, A is an electron-acceptor functionality selected from the group consisting of -NO2, CN, -F, -Cl, -CF3,- OCF3, cyanovinyl, dicyanovinyl and tricyanovinyl moieties, and n is an integer from 1 to 3. The invention also relates to a dielectric polyurethane polymer produced by the process and to use of said polyurethane polymer. |
