Patent ID: 6489379
Filing Date: 2002-12-03
Classification: C08F,C08L

Abstract:
A thermoplastic ABS moulding composition comprising:A) at least one elastic/thermoplastic graft polymer prepared by radical emulsion polymerisation of resin-forming vinyl monomers in the presence of rubber existing in latex form with a glass transition temperature &lE;0Â° C. using an initiator combination consisting of a redox initiator system and a persulfate compound; and B) at least one copolymer composed of styrene and acrylonitrile and optionally further comonomers, wherein graft polymer A) is produced by the steps of,(i) supplying a portion of the vinyl monomers to the rubber latex, (ii) adding the redox initiator components at the beginning of the graft polymerisation reaction in quantities of 0.1 to 2.5 wt. % (based on the monomers added up to the moment of addition of persulfate compound in each case), (iii) adding said persulfate compound after an addition of monomers of 10 to 95 wt. % (based on total quantity of monomer in each case), in quantities of 0.05 to 1.5 wt. % (based on the monomers added from the moment of addition of persulfate compound in each case), and (iv) allowing polymerisation to proceed to completion, further wherein the rubber existing in latex form of graft polymer A) is a mixture of at least two rubber latices having,a) an average particle diameter d50&lE;320 nm and a gel content &lE;70 wt. %, and b) an average particle diameter d50&gE;370 nm, and a gel content &gE;70 wt. %.