Macrocyclic polycarbonates

The subject of the instant invention are polycarbonates based on diphenols of the formula I (I) wherein Y is a single bond, an elkylene- or alkylidene-radical with 1 to 7 carbon atoms, a cycloalkylene- or cycloalkylidene-radical with 5 to 12 carbon atoms, which have weight average molecular weights (MLS) measured by light scattering of at least 15 000 and which are characterized in having an average of zero to 1.5 mols, preferably 0.3 to 1.0 mols and especially 0.3 to 0.8 mols endgroups per mol polycarbonate. The subject of instant invention is also a process for preparing these polycarbonates according to the interfacial polycondensation method, the polycarbonates thus obtained and the use of the polycarbonates according instant invention for the preparation of compounds and films.