Patent ID: 7649074

Claim:
A high-functionality, highly branched or hyperbranched polycarbonate produced by a process comprising a) preparing one or more condensation products (K) by (a1) reacting at least one aliphatic organic carbonate (A) of general formula RO[(CO)O] n R with at least one aliphatic alcohol (B1) comprising at least 3 OH groups, with elimination of alcohols ROH, R, independently at each occurrence, being a straight-chain or branched aliphatic 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 at least one aliphatic alcohol (B1), with release of hydrogen chloride, and b) intermolecularly reacting the one or more 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 aliphatic 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, wherein the high-functionality, highly branched or hyperbranched polycarbonate has a weight average molecular weight M w of between 3,300 and 150,000 g/mol, wherein the degree of crosslinking of the high-functionality, highly branched or hyperbranched polycarbonate is less than 15%, and wherein the degree of branching of the high-functionality, highly branched or hyperbranched polycarbonate ranges from 10% to 99.9%.