Transparent, free-flowing polycarbonate mixts. - contain 90-99.5 wt. per cent thermoplastic aromatic polycarbonate and 10-0.5 wt. per cent aliphatic polycarbonate with MW below 15,000

摘要

Polycarbonate mixts. (I) are claimed, contg. (1) 90-99.5 wt% thermoplastic aromatic polycarbonate (PC) and (2) 10-0.5 wt% aliphatic polycarbonate with Mw 300-14,999 (measured by ultracentrifuging or light scattering). Also claimed is prepn. of (I), by mixing the components, and opt. stabilisers, pigment concentrates, mould release agents, fire retardants and/or antistatics, by known methods and then processing by melt compounding or melt extrusion in conventional appts. at 200-330 deg. C. Pref. component (2) has Mw 500-13,00. (I) can also contain additives as listed above. USE/ADVANTAGE - Used esp. for the prodn. of injection moulded prods. such as parts for domestic appliances, sheeting for building and garden applications, optical lenses etc. Addn. of component (2) gives PC mixts. with excellent toughness and melt flow properties, combined with the high transparency of the base PC (1) (aliphatic PC with mol. wt. above 15,000 has an adverse effect on transparency - see, e.g. EP 332989 and US 4900797). W.r.t. pure (1), mixts. (I) also have improved hydrolytic stability, lower water absorption, better mould release properties and higher elastic modulus.