Polystyrene hard foam with aluminium pigments, method for producing it and use of same

摘要

Polystyrene rigid foam comprises aluminum pigments comprising a metallic core exhibiting an elemental aluminum content of at least 50 wt.%. The aluminum pigments are present in the form of flakes exhibiting an average particle size of 1-25 mu m, and in the form of aluminum powder comprising particles exhibiting an average diameter of 0.5-25 mu m. The proportion of the aluminum powder in the aluminum pigments is 60-90 wt.%. The proportion of the aluminum flakes in the aluminum pigment is 40-10 wt.%. The aluminum pigments are present as a homogeneous mixture in the polystyrene foam. Independent claims are also included for: (1) producing extruded polystyrene rigid foam, comprising (a1) introducing the aluminum pigments into a propellant-containing styrene polymer- and/or styrene copolymer melt or (a2) introducing the aluminum pigments into the styrene polymer- and/or styrene copolymer to obtain a homogenous mixture, and melting the aluminum pigments-containing styrene polymer and/or styrene copolymer in presence or with the addition of the propellant, and (b) extruding and foaming the melt to obtain extruded aluminum pigment-containing polystyrene rigid foam; and (2) producing expanded polystyrene rigid foam, comprising steps (a1) or (a2), (b1) extruding the melt to obtain aluminum pigment-containing styrene polymer- and/or styrene copolymer particles, and (c) foaming the styrene polymer- and/or styrene copolymer particles obtained in step (b) to obtain the expanded aluminum pigments-containing polystyrene rigid foam.