USE OF HYPERBRANCHED POLYCARBONATES AS A DISPERSING AGENT FOR PIGMENTS

摘要

Disclosed is the use of highly functional, highly branched or hyperbranched polycarbonates as a dispersing agent for pigments. Said polycarbonates can be obtained by a) producing one or several different condensation products (K) by 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 (B) comprising at least 3 OH groups while eliminating alcohols ROH, R independently representing a linear or branched aliphatic, aromatic/aliphatic, or aromatic hydrocarbon radical containing 1 to 20 C atoms, and radicals R being optionally interconnected so as to form a ring containing the grouping -O[(CO)O]_n-, and n representing an integer ranging from 1 to 5, or a2) reacting phosgene, diphosgene, or triphosgene with the aliphatic, aliphatic/aromatic, or aromatic alcohol (B) while releasing hydrogen chloride, the quantitative ratio between alcohols (B) and the carbonates (A) or the phosgenes in the reaction mixture being selected such that the condensation products (K) on average are provided with one carbonate group or carbamyl chloride group and more than one OH group or one OH group and more than one carbonate group or carbamyl chloride group, and b) intermolecularly reacting the condensation products (K) obtained in step a).