Polycarbonates with end groups containing double bonds which can be crosslinked by UV light

摘要

High molecular weight aromatic polycarbonates having molecular weights Mw (weight average) of between about 10,000 and 200,000, which are based on diphenols and monofunctional chain stoppers, which correspond to the general formula <IMAGE> (I) in which Z denotes the radical of a diphenol, n denotes an integer from 20 to 400, E denotes <IMAGE> m is 0 or 1 and R denotes a hydrogen atom or a C1 to C3 alkyl group, and in which between about 0.5 and 5 mol % of Z are radicals of aromatic dihydroxyketones. These polycarbonates share mechanical and thermal properties with known polycarbonates but in addition are suitable for crosslinking, for example in the presence of photoinitiators and optionally photo-reducing agents and under irradiation with UV light. When crosslinked they are resistant to organic solvents and insensitive to stress-cracking, and have particularly good flame-repellent properties when additionally incorporating flameproofing agents.