Polyvinyl chloride, polycarbonate and thermoplastic blend - prepd. by melt mixing with pre-homogenisation of polycarbonate and thermoplast

摘要

A blend contains (A) 10-90 wt.%, wr.t. (A)+(B), of PVC or a copolymer of vinyl chloride with up to 30 wt.% of a copolymerisable vinyl cpd., (B) 90-10% w.r.t. (A)+(B), of a polycarbonate in which at least 50 wt.% of the units have formula (I), (C) 2-200 wt.%, w.r.t. 100 wt.% of (A)+(B), of (C1) a thermoplastic polymer from a styrene cpd., a (meth)acrylic cpd., and maleic anhdyride or derivs. and/or (C2) a graft polymer of 1 or more of these monomers on rubber(s), (D) 0-60 wt.%, w.r.t. 100% of (A)+(B) of a rubber, and/or (E) stabilisers, lubricants, pigments, fillers, glass fibres, antistatics, flame protectants, plasticisers and/or blowing agents. The components are melt-mixed, and the polycarbonate is thermoplastically homogenised with (part of) (C1) and/or (c2) in a separate process, before being thermoplastically homogenised with the remaining components. X = a bond, O, CO, SO2 1-6C alkylene or alkylidene, 5-15C cycloalkylene or cycloalkylidene or gp. (II). USE/ADVANTAGE - The temp. of the final homogenisation process can be 190 deg.C, compared with 260 deg.C when all the components are mixed at the same time. A large-scale process is possible. Smaller amts. of heat-stabiliser are needed, and the blends have better properties, e.g. mechanical properties (e.g. notch impact strength), Vicat temp. and colour. The blends can be used plates, profiles and pipes, esp. in building.