| abstract |
The present invention relates to a process for producing a dielectric polyurethane film, in which at least the following steps are performed continuously: I) a mixture comprising: a) a compound containing isocyanate groups and having a content of isocyanate groups of >10% by weight and ≦50% by weight, b) a compound containing isocyanate-reactive groups and having an OH number of ≧20 and ≦150, at least one solvent having a vapor pressure at 20° C. of >0.1 mbar and <200 mbar, at least one wetting additive, is produced, where the sum of the number-average functionalities of isocyanate groups and of isocyanate-reactive groups in the compounds a) and b) is ≧2.6 and ≦6, II) immediately after production thereof, the mixture is applied to a carrier in the form of a wet film, III) the wet film is cured to form the polyurethane film and IV) the polyurethane film is separated from the carrier. The invention further provides a dielectric polyurethane film obtainable by the process according to the invention, a process for producing an electromechanical transducer, and an electromechanical transducer obtainable by this process. |