| 摘要 |
Films and membranes produced therefrom for acoustic signal converters made of polyester comprising the structural unit of formula (I) wherein R1 and R2 independently represent hydrogen, halogen, C1-C8 alkyl, C5-C6 cycloalkyl, C6-C10 aryl, C7-C12 aralkyl and R3 corresponds to a carbonyl group or to the formula (A) |
