High-Functionality Highly Branched Or Hyperbranched Polycarbonates And Their Preparation And Use

A high-functionality, highly branched or hyperbranched polycarbonate produced by the process comprising

• a) preparing one or more condensation products (K) by either
• (a1) reacting at least one organic carbonate (A) of general formula RO[(CO)O]nR with at least one aliphatic, aliphatic/aromatic or aromatic alcohol (B1) containing at least 3 OH groups, with elimination of alcohols ROH, R, independently at each occurrence, being a straight-chain or branched aliphatic, aromatic/aliphatic or aromatic hydrocarbon radical having 1 to 20 carbon atoms, and it also being possible for the radicals R to be joined to one another to form a ring, and n is an integer from 1 to 5, or
• (a2) reacting phosgene, diphosgene or triphosgene with said aliphatic, aliphatic/aromatic or aromatic alcohol (B1), with release of hydrogen chloride, and
• b) intermolecularly reacting the condensation products (K) to produce the high-functionality, highly branched or hyperbranched polycarbonate,
• wherein the proportion of the OH groups to the phosgenes or the carbonates in the reaction mixture being chosen such that the condensation products (K) contain on average either one carbonate or carbamoyl chloride group and more than one OH group, or one OH group and more than one carbonate or carbamoyl chloride group.